China Shenzhen Perfect Precision Product Co., Ltd. company news

According to the phys website on September 22, if you put an aluminum spoon in a tank filled with water, the spoon will sink to the bottom. Alexander Boldyrev, a chemist at Utah State University, said that this is because conventional aluminum metals are denser than water. However, if the structure of ordinary household metals can be redesigned at the molecular level (as Boldyrev and his colleagues did with computer modeling), ultralight crystalline aluminum with a density smaller than that of water can be produced. Boldyrev and scientists ILIYA getmanskii, Vitaly Koval, Russian minyaev and Vladimir Minkin from the Southern Federal University of rostovtang state in Russia published their research findings and results on the online edition of the Journal of Physical Chemistry C on September 18, 2017. The team's research was supported by the National Science Foundation and the Russian Ministry of science and education. Boldyrev, a professor in the Department of chemistry and biochemistry of Utah State University in the United States, said: "the challenge proposed by my colleagues is very innovative. They started with diamond, a known lattice type material, and used aluminum atoms to replace each carbon atom in the diamond lattice to obtain a new tetrahedron." Through the simulation calculation of the team, it can be proved that this structure has a new, metastable and light aluminum crystal form. Moreover, it is surprising that the density of the aluminum material having this structure is only 0.61 g / cc compared to the conventional aluminum having a density of 2.7 g / cc. "This means that the material obtained by crystallization in this form will be able to float on water because the density of water is 1 g / cc." Boldyrev said. This characteristic will make the application of non-magnetic metals, corrosion-resistant metals, high-yield metals, relatively low-cost and easy to produce metals and other materials to a new height. BodyRev said: "the space shuttle, medicine, wiring and more light and fuel-efficient automobile parts are some of the application fields that I think of at present. Of course, it is too early to consider the use of this material. There are still many unknown points to study about this material, for example, we know nothing about its strength." However, BodyRev also said that this breakthrough discovery still marks the emergence of a new material design method. Boldyrev said: "the most exciting aspect of this research is that it has obtained a new design method: using a known structure to design new materials. This method will pave the way for further discoveries in the future."

With the continuous improvement of human requirements for living environment, the environmental problems involved in the PCB production process are particularly prominent. At present, lead and bromine are the hottest topics; Lead free and halogen-free will affect the development of PCB in many aspects. Although at present, the changes in the surface treatment process of PCB are not great, and it seems that it is still a distant thing, it should be noted that long-term slow changes will lead to great changes. With the increasing demand for environmental protection, the surface treatment process of PCB will certainly undergo great changes in the future. Purpose of surface treatment The basic purpose of surface treatment is to ensure good solderability or electrical performance. Since copper in nature tends to exist in the form of oxide in the air, it is unlikely to remain as original copper for a long time, so other treatments are required for copper. Although in the subsequent assembly, strong flux can be used to remove most of the copper oxide, it is not easy to remove the strong flux itself, so the industry generally does not use strong flux. Common surface treatment process At present, there are many PCB surface treatment processes, including hot air leveling, organic coating, electroless nickel plating / gold dipping, silver dipping and tin dipping, which will be introduced one by one.   1. Hot air leveling Hot air leveling, also known as hot air solder leveling, is a process of coating molten tin lead solder on the surface of PCB and leveling (blowing) with heated compressed air to form a coating layer that is resistant to copper oxidation and provides good solderability. Copper tin intermetallic compound is formed at the junction of solder and copper by hot air leveling. The thickness of the solder protecting the copper surface is about 1-2 mil. PCB shall be immersed in molten solder during hot air leveling; The air knife blows the liquid solder before the solder solidifies; The wind blade can minimize the meniscus of solder on the copper surface and prevent solder bridging. Hot air leveling is divided into vertical type and horizontal type. It is generally considered that the horizontal type is better, mainly because the horizontal hot air leveling coating is more uniform and can realize automatic production. The general process of hot air leveling process is: Micro etching → preheating → coating flux → spraying tin → cleaning. 2. Organic coating The organic coating process is different from other surface treatment processes in that it acts as a barrier layer between copper and air; Organic coating technology is simple and low cost, which makes it widely used in the industry. The early organic coating molecules are imidazole and benzotriazole, which play the role of rust prevention. The latest molecule is mainly benzimidazole, which is the copper that chemically bonds the nitrogen functional group to the PCB. In the subsequent welding process, if there is only one organic coating layer on the copper surface, it is not possible. There must be many layers. This is why liquid copper is usually added to the chemical tank. After coating the first layer, the coating layer adsorbs copper; Then, the organic coating molecules of the second layer are combined with copper until 20 or even 100 times of organic coating molecules gather on the copper surface, which can ensure multiple reflow soldering. The experiment shows that the latest organic coating technology can keep good performance in many lead-free welding processes. The general process of the organic coating process is: degreasing → micro etching → pickling → pure water cleaning → organic coating → cleaning. The process control is easier than other surface treatment processes. 3. Electroless nickel plating / gold immersion electroless nickel plating / gold immersion process Unlike organic coating, electroless nickel plating / gold impregnation seems to put thick armor on PCB; In addition, the electroless nickel plating / gold dipping process is not like the organic coating as the antirust barrier layer. It can be useful in the long-term use of PCB and achieve good electrical performance. Therefore, electroless nickel plating / gold immersion is to wrap a thick layer of nickel gold alloy with good electrical properties on the copper surface, which can protect the PCB for a long time; In addition, it also has environmental tolerance that other surface treatment processes do not have. The reason for nickel plating is that gold and copper will diffuse each other, and the nickel layer can prevent the diffusion between gold and copper; Without the nickel layer, the gold will diffuse into the copper within hours. Another advantage of electroless nickel plating / gold impregnation is the strength of nickel. Only 5 microns of nickel can limit the expansion in the Z direction at high temperature. In addition, electroless nickel plating / gold immersion can also prevent the dissolution of copper, which will be beneficial for lead-free assembly. The general process of electroless nickel plating / gold leaching process is: acidic cleaning → micro etching → prepreg → activation → electroless nickel plating → electroless gold leaching. There are mainly 6 chemical tanks, involving nearly 100 chemicals, so the process control is difficult. 4. Silver leaching process Between organic coating and electroless nickel plating / gold leaching, the process is relatively simple and fast; It is not as complicated as electroless nickel plating / gold immersion, nor does it put a thick layer of armor on the PCB, but it can still provide good electrical performance. Silver is the little brother of gold. Even if exposed to heat, humidity and pollution, silver can still maintain good solderability, but it will lose luster. Silver immersion does not have the good physical strength of electroless nickel plating / gold immersion because there is no nickel under the silver layer. In addition, the silver impregnation has good storage property, and there will be no big problem when it is put into assembly for several years after the silver impregnation. Silver impregnation is a displacement reaction, which is almost submicron pure silver coating. Sometimes, some organic substances are included in the process of silver leaching, mainly to prevent silver corrosion and eliminate silver migration; It is generally difficult to measure this thin layer of organic matter, and analysis shows that the weight of the organism is less than 1%. 5. Tin immersion Since all solders are based on tin, the tin layer can match any type of solder. From this point of view, the tin dipping process has great development prospects. However, tin whiskers appear after the previous PCB is dipped in tin. During the welding process, the migration of tin whiskers and tin will bring reliability problems. Therefore, the use of tin dipping process is limited. Later, organic additives were added to the tin immersion solution, which can make the tin layer structure appear granular structure, overcome the previous problems, and have good thermal stability and solderability. The tin dipping process can form a flat copper tin intermetallic compound, which makes the tin dipping have the same good solderability as hot-air leveling without the headache of flatness caused by hot-air leveling; There is no diffusion problem between electroless nickel plating / gold dipping metals in tin dipping - copper tin intermetallic compounds can be firmly bonded together. The tin immersion plate shall not be stored for too long, and the assembly must be carried out according to the sequence of tin immersion. 6. Other surface treatment processes Other surface treatment processes are less applied. The nickel gold plating and electroless palladium plating processes that are relatively more applied are as follows. Nickel gold plating is the originator of PCB surface treatment process. It has appeared since the appearance of PCB, and has gradually evolved into other methods. It is to first coat the conductor on the PCB surface with a layer of nickel and then a layer of gold. Nickel plating is mainly to prevent the diffusion between gold and copper. There are two types of nickel gold plating at present: soft gold plating (pure gold, the gold surface does not look bright) and hard gold plating (the surface is smooth and hard, wear-resistant, contains cobalt and other elements, and the gold surface looks bright). Soft gold is mainly used for gold wire during chip packaging; Hard gold is mainly used for electrical interconnection at non welded places. In consideration of the cost, the industry often uses image transfer method for selective plating to reduce the use of gold. At present, the use of selective gold plating in the industry continues to increase, which is mainly due to the difficulty in controlling the process of electroless nickel plating / gold leaching. Under normal circumstances, welding will lead to embrittlement of plated gold, which will shorten the service life. Therefore, welding on plated gold should be avoided; However, due to the thin and consistent gold of electroless nickel plating / gold immersion, embrittlement rarely occurs. The process of electroless palladium plating is similar to that of electroless nickel plating. The main process is to reduce palladium ions to palladium on the catalytic surface through a reducing agent (such as sodium dihydrogen hypophosphite). The newly formed palladium can become a catalyst to promote the reaction, so any thickness of palladium coating can be obtained. The advantages of electroless palladium plating are good welding reliability, thermal stability and surface flatness. Selection of surface treatment process The choice of surface treatment process mainly depends on the type of final assembled components; The surface treatment process will affect the production, assembly and final use of PCB. The following will specifically introduce the application occasions of the five common surface treatment processes. 1. Hot air leveling Hot air leveling once played a leading role in PCB surface treatment process. In the 1980s, more than three quarters of PCBs used hot-air leveling technology. However, the industry has been reducing the use of hot-air leveling technology in the past decade. It is estimated that about 25% - 40% of PCBs currently use hot-air leveling technology. Hot air leveling process is dirty, smelly and dangerous, so it has never been a favorite process. However, hot air leveling is an excellent process for larger components and wires with larger spacing. In the PCB with high density, the flatness of hot air leveling will affect the subsequent assembly; Therefore, the hot air leveling process is generally not used for HDI boards. With the progress of technology, the hot air leveling process suitable for assembling QFP and BGA with smaller spacing has appeared in the industry, but the actual application is less. At present, some factories use organic coating and electroless nickel plating / gold dipping process to replace the hot air leveling process; Technological development has also led some factories to adopt tin and silver impregnation processes. With the lead-free trend in recent years, the use of hot air leveling is further restricted. Although the so-called lead-free hot air leveling has appeared, it may involve the compatibility of equipment. 2. Organic coating It is estimated that at present, about 25% - 30% of PCBs use organic coating technology, and the proportion has been rising (it is likely that organic coating has now surpassed hot-air leveling in the first place). The organic coating process can be used for low-tech PCB or high-tech PCB, such as single-sided TV PCB and high-density chip packaging board. For BGA, organic coating is also widely used. If PCB has no functional requirements for surface connection or storage period, organic coating will be the most ideal surface treatment process. 3. Electroless nickel plating / gold immersion electroless nickel plating / gold immersion process Different from organic coating, it is mainly used on boards with functional requirements for connection and long storage life on the surface, such as mobile phone key area, edge connection area of router shell and electrical contact area of elastic connection of chip processor. Due to the flatness of hot-air leveling and the removal of organic coating flux, electroless nickel plating / gold impregnation was widely used in the 1990s; Later, due to the appearance of black disk and brittle nickel phosphorus alloy, the application of electroless nickel plating / gold dipping process was reduced. However, at present, almost every high-tech PCB Factory has electroless nickel plating / gold dipping line. Considering that the solder joint will become brittle when the copper tin intermetallic compound is removed, many problems will occur at the relatively brittle nickel tin intermetallic compound. Therefore, almost all portable electronic products (such as mobile phones) use copper tin intermetallic compound solder joints formed by organic coating, silver immersion or tin immersion, while electroless nickel plating / gold immersion is used to form key areas, contact areas and EMI shielding areas. It is estimated that at present, about 10% - 20% of PCBs use electroless nickel plating / gold impregnation process. 4. Silver immersion It is cheaper than electroless nickel plating / gold immersion. If PCB has functional requirements and needs to reduce costs, silver immersion is a good choice; In addition to the good flatness and contact of silver impregnation, the silver impregnation process should be selected. Silver immersion is widely used in communication products, automobiles and computer peripherals, and also in high-speed signal design. Silver impregnation can also be used in high-frequency signals because of its excellent electrical properties that can not be matched by other surface treatments. EMS recommends the silver impregnation process because it is easy to assemble and has good inspectability. However, due to the defects such as tarnish and solder hole in the silver impregnation, its growth is slow (but not decreased). It is estimated that about 10% - 15% of PCBs currently use silver impregnation process. 5. Tin immersion It has been nearly ten years since tin was introduced into the surface treatment process. The appearance of this process is the result of the requirements of production automation. The tin impregnation does not bring any new elements into the welding place, and is especially suitable for the communication backplane. Tin will lose solderability beyond the storage period of the board, so better storage conditions are required for tin immersion. In addition, the use of tin impregnation process is restricted due to carcinogenic substances. It is estimated that about 5% - 10% of PCBs currently use the tin dipping process. V Conclusion: with the increasingly high requirements of customers, stricter environmental requirements and more and more surface treatment processes, it seems that it is a bit confusing and confusing to choose the surface treatment process with better development prospects and stronger universality. Where the PCB surface treatment process will go in the future can not be accurately predicted now. In any case, meeting customer requirements and protecting the environment must be done first!

With the continuous improvement of human requirements for living environment, the environmental problems involved in the PCB production process are particularly prominent. At present, lead and bromine are the hottest topics; Lead free and halogen-free will affect the development of PCB in many aspects. Although at present, the changes in the surface treatment process of PCB are not great, and it seems that it is still a distant thing, it should be noted that long-term slow changes will lead to great changes. With the increasing demand for environmental protection, the surface treatment process of PCB will certainly undergo great changes in the future. Purpose of surface treatment The basic purpose of surface treatment is to ensure good solderability or electrical performance. Since copper in nature tends to exist in the form of oxide in the air, it is unlikely to remain as original copper for a long time, so other treatments are required for copper. Although in the subsequent assembly, strong flux can be used to remove most of the copper oxide, it is not easy to remove the strong flux itself, so the industry generally does not use strong flux. Common surface treatment process At present, there are many PCB surface treatment processes, including hot air leveling, organic coating, electroless nickel plating / gold dipping, silver dipping and tin dipping, which will be introduced one by one.   1. Hot air leveling Hot air leveling, also known as hot air solder leveling, is a process of coating molten tin lead solder on the surface of PCB and leveling (blowing) with heated compressed air to form a coating layer that is resistant to copper oxidation and provides good solderability. Copper tin intermetallic compound is formed at the junction of solder and copper by hot air leveling. The thickness of the solder protecting the copper surface is about 1-2 mil. PCB shall be immersed in molten solder during hot air leveling; The air knife blows the liquid solder before the solder solidifies; The wind blade can minimize the meniscus of solder on the copper surface and prevent solder bridging. Hot air leveling is divided into vertical type and horizontal type. It is generally considered that the horizontal type is better, mainly because the horizontal hot air leveling coating is more uniform and can realize automatic production. The general process of hot air leveling process is: Micro etching → preheating → coating flux → spraying tin → cleaning. 2. Organic coating The organic coating process is different from other surface treatment processes in that it acts as a barrier layer between copper and air; Organic coating technology is simple and low cost, which makes it widely used in the industry. The early organic coating molecules are imidazole and benzotriazole, which play the role of rust prevention. The latest molecule is mainly benzimidazole, which is the copper that chemically bonds the nitrogen functional group to the PCB. In the subsequent welding process, if there is only one organic coating layer on the copper surface, it is not possible. There must be many layers. This is why liquid copper is usually added to the chemical tank. After coating the first layer, the coating layer adsorbs copper; Then, the organic coating molecules of the second layer are combined with copper until 20 or even 100 times of organic coating molecules gather on the copper surface, which can ensure multiple reflow soldering. The experiment shows that the latest organic coating technology can keep good performance in many lead-free welding processes. The general process of the organic coating process is: degreasing → micro etching → pickling → pure water cleaning → organic coating → cleaning. The process control is easier than other surface treatment processes. 3. Electroless nickel plating / gold immersion electroless nickel plating / gold immersion process Unlike organic coating, electroless nickel plating / gold impregnation seems to put thick armor on PCB; In addition, the electroless nickel plating / gold dipping process is not like the organic coating as the antirust barrier layer. It can be useful in the long-term use of PCB and achieve good electrical performance. Therefore, electroless nickel plating / gold immersion is to wrap a thick layer of nickel gold alloy with good electrical properties on the copper surface, which can protect the PCB for a long time; In addition, it also has environmental tolerance that other surface treatment processes do not have. The reason for nickel plating is that gold and copper will diffuse each other, and the nickel layer can prevent the diffusion between gold and copper; Without the nickel layer, the gold will diffuse into the copper within hours. Another advantage of electroless nickel plating / gold impregnation is the strength of nickel. Only 5 microns of nickel can limit the expansion in the Z direction at high temperature. In addition, electroless nickel plating / gold immersion can also prevent the dissolution of copper, which will be beneficial for lead-free assembly. The general process of electroless nickel plating / gold leaching process is: acidic cleaning → micro etching → prepreg → activation → electroless nickel plating → electroless gold leaching. There are mainly 6 chemical tanks, involving nearly 100 chemicals, so the process control is difficult. 4. Silver leaching process Between organic coating and electroless nickel plating / gold leaching, the process is relatively simple and fast; It is not as complicated as electroless nickel plating / gold immersion, nor does it put a thick layer of armor on the PCB, but it can still provide good electrical performance. Silver is the little brother of gold. Even if exposed to heat, humidity and pollution, silver can still maintain good solderability, but it will lose luster. Silver immersion does not have the good physical strength of electroless nickel plating / gold immersion because there is no nickel under the silver layer. In addition, the silver impregnation has good storage property, and there will be no big problem when it is put into assembly for several years after the silver impregnation. Silver impregnation is a displacement reaction, which is almost submicron pure silver coating. Sometimes, some organic substances are included in the process of silver leaching, mainly to prevent silver corrosion and eliminate silver migration; It is generally difficult to measure this thin layer of organic matter, and analysis shows that the weight of the organism is less than 1%. 5. Tin immersion Since all solders are based on tin, the tin layer can match any type of solder. From this point of view, the tin dipping process has great development prospects. However, tin whiskers appear after the previous PCB is dipped in tin. During the welding process, the migration of tin whiskers and tin will bring reliability problems. Therefore, the use of tin dipping process is limited. Later, organic additives were added to the tin immersion solution, which can make the tin layer structure appear granular structure, overcome the previous problems, and have good thermal stability and solderability. The tin dipping process can form a flat copper tin intermetallic compound, which makes the tin dipping have the same good solderability as hot-air leveling without the headache of flatness caused by hot-air leveling; There is no diffusion problem between electroless nickel plating / gold dipping metals in tin dipping - copper tin intermetallic compounds can be firmly bonded together. The tin immersion plate shall not be stored for too long, and the assembly must be carried out according to the sequence of tin immersion. 6. Other surface treatment processes Other surface treatment processes are less applied. The nickel gold plating and electroless palladium plating processes that are relatively more applied are as follows. Nickel gold plating is the originator of PCB surface treatment process. It has appeared since the appearance of PCB, and has gradually evolved into other methods. It is to first coat the conductor on the PCB surface with a layer of nickel and then a layer of gold. Nickel plating is mainly to prevent the diffusion between gold and copper. There are two types of nickel gold plating at present: soft gold plating (pure gold, the gold surface does not look bright) and hard gold plating (the surface is smooth and hard, wear-resistant, contains cobalt and other elements, and the gold surface looks bright). Soft gold is mainly used for gold wire during chip packaging; Hard gold is mainly used for electrical interconnection at non welded places. In consideration of the cost, the industry often uses image transfer method for selective plating to reduce the use of gold. At present, the use of selective gold plating in the industry continues to increase, which is mainly due to the difficulty in controlling the process of electroless nickel plating / gold leaching. Under normal circumstances, welding will lead to embrittlement of plated gold, which will shorten the service life. Therefore, welding on plated gold should be avoided; However, due to the thin and consistent gold of electroless nickel plating / gold immersion, embrittlement rarely occurs. The process of electroless palladium plating is similar to that of electroless nickel plating. The main process is to reduce palladium ions to palladium on the catalytic surface through a reducing agent (such as sodium dihydrogen hypophosphite). The newly formed palladium can become a catalyst to promote the reaction, so any thickness of palladium coating can be obtained. The advantages of electroless palladium plating are good welding reliability, thermal stability and surface flatness. Selection of surface treatment process The choice of surface treatment process mainly depends on the type of final assembled components; The surface treatment process will affect the production, assembly and final use of PCB. The following will specifically introduce the application occasions of the five common surface treatment processes. 1. Hot air leveling Hot air leveling once played a leading role in PCB surface treatment process. In the 1980s, more than three quarters of PCBs used hot-air leveling technology. However, the industry has been reducing the use of hot-air leveling technology in the past decade. It is estimated that about 25% - 40% of PCBs currently use hot-air leveling technology. Hot air leveling process is dirty, smelly and dangerous, so it has never been a favorite process. However, hot air leveling is an excellent process for larger components and wires with larger spacing. In the PCB with high density, the flatness of hot air leveling will affect the subsequent assembly; Therefore, the hot air leveling process is generally not used for HDI boards. With the progress of technology, the hot air leveling process suitable for assembling QFP and BGA with smaller spacing has appeared in the industry, but the actual application is less. At present, some factories use organic coating and electroless nickel plating / gold dipping process to replace the hot air leveling process; Technological development has also led some factories to adopt tin and silver impregnation processes. With the lead-free trend in recent years, the use of hot air leveling is further restricted. Although the so-called lead-free hot air leveling has appeared, it may involve the compatibility of equipment. 2. Organic coating It is estimated that at present, about 25% - 30% of PCBs use organic coating technology, and the proportion has been rising (it is likely that organic coating has now surpassed hot-air leveling in the first place). The organic coating process can be used for low-tech PCB or high-tech PCB, such as single-sided TV PCB and high-density chip packaging board. For BGA, organic coating is also widely used. If PCB has no functional requirements for surface connection or storage period, organic coating will be the most ideal surface treatment process. 3. Electroless nickel plating / gold immersion electroless nickel plating / gold immersion process Different from organic coating, it is mainly used on boards with functional requirements for connection and long storage life on the surface, such as mobile phone key area, edge connection area of router shell and electrical contact area of elastic connection of chip processor. Due to the flatness of hot-air leveling and the removal of organic coating flux, electroless nickel plating / gold impregnation was widely used in the 1990s; Later, due to the appearance of black disk and brittle nickel phosphorus alloy, the application of electroless nickel plating / gold dipping process was reduced. However, at present, almost every high-tech PCB Factory has electroless nickel plating / gold dipping line. Considering that the solder joint will become brittle when the copper tin intermetallic compound is removed, many problems will occur at the relatively brittle nickel tin intermetallic compound. Therefore, almost all portable electronic products (such as mobile phones) use copper tin intermetallic compound solder joints formed by organic coating, silver immersion or tin immersion, while electroless nickel plating / gold immersion is used to form key areas, contact areas and EMI shielding areas. It is estimated that at present, about 10% - 20% of PCBs use electroless nickel plating / gold impregnation process. 4. Silver immersion It is cheaper than electroless nickel plating / gold immersion. If PCB has functional requirements and needs to reduce costs, silver immersion is a good choice; In addition to the good flatness and contact of silver impregnation, the silver impregnation process should be selected. Silver immersion is widely used in communication products, automobiles and computer peripherals, and also in high-speed signal design. Silver impregnation can also be used in high-frequency signals because of its excellent electrical properties that can not be matched by other surface treatments. EMS recommends the silver impregnation process because it is easy to assemble and has good inspectability. However, due to the defects such as tarnish and solder hole in the silver impregnation, its growth is slow (but not decreased). It is estimated that about 10% - 15% of PCBs currently use silver impregnation process. 5. Tin immersion It has been nearly ten years since tin was introduced into the surface treatment process. The appearance of this process is the result of the requirements of production automation. The tin impregnation does not bring any new elements into the welding place, and is especially suitable for the communication backplane. Tin will lose solderability beyond the storage period of the board, so better storage conditions are required for tin immersion. In addition, the use of tin impregnation process is restricted due to carcinogenic substances. It is estimated that about 5% - 10% of PCBs currently use the tin dipping process. V Conclusion: with the increasingly high requirements of customers, stricter environmental requirements and more and more surface treatment processes, it seems that it is a bit confusing and confusing to choose the surface treatment process with better development prospects and stronger universality. Where the PCB surface treatment process will go in the future can not be accurately predicted now. In any case, meeting customer requirements and protecting the environment must be done first!

The same is true in the plastic industry. The hardness, wear resistance, toughness, cracking resistance, collapse angle resistance, corrosion resistance and processing accuracy of plastic molds make them very popular. So, what is the future development trend of plastic mold? 1、 High quality The development trend of die steel in Europe and America is that carbon tool steel, low alloy tool steel and high alloy tool steel have successively appeared a series of new die materials, and the alloying degree of die standard steel is also increasing. 1. Development trend of new plastic die steel abroad Plastic mold steel with good free cutting and polishing properties, such as 412 and M-300 of the United States, YAG of Japan, EAB of the United Kingdom, stavax-13 of Sweden, etc; Pre hardened plastic die steel, such as P20 and 445 in the United States, PDS in Japan, movtrex-a (2312) in Germany, etc; Integrally hardened plastic die steel, such as A2, D3 and H13 in the United States; Corrosion resistant plastic die steel, such as 110cr-mo17 in the national standard ISO and 4Cr13 in the Swedish Assab company. 2. Advanced die surface treatment technology The surface of die was treated by multi-element infiltration and compound infiltration instead of single element infiltration. The coating on the mold surface can be tic, tin, TiCN, TiAlN, CrN, Cr7C3, W2C, etc. the coating can be prepared by physical vapor deposition, chemical vapor deposition, physical chemical vapor deposition, ion penetration, ion implantation and other methods. 2、 High accuracy The high-speed scanner and the mold scanning system provide many functions required from the model or the physical object scanning to the processing of the desired model, greatly shortening the mold development and manufacturing cycle. The mold scanning system has been successfully applied in the European and American mold industry. The equipment in this respect, such as the high-speed scanner (cyclonseries 2) of Renishaw company, can realize the complementary advantages of the laser probe and the contact probe. The laser scanning accuracy is 0.05mm and the contact probe scanning accuracy is 0.02mm. 3、 High efficiency 1. High speed cutting technology is widely used It is generally used for large-scale panel dies, and its surface processing accuracy can reach 0.01mm. After high-speed milling and finishing, the mold surface can be used only with a little polishing, saving a lot of time for grinding and polishing. High speed machining greatly shortens the mold making cycle, thus improving the market competitiveness of products. 2. Combination of rapid prototyping technology and rapid tooling technology The combination of rapid prototyping technology and rapid tooling technology is applied to mold manufacturing, that is, the prototype of product parts is manufactured by rapid prototyping technology, and then the mold is rapidly manufactured based on the prototype. The cost of using this technology from mold design to manufacturing is only 1 / 3 of that of traditional methods. The rapid prototype casting silicone rubber mold is used for turning a small number of plastic parts, which is very suitable for the trial production of products. The injection mold made of aluminum can shorten the injection cycle by 25-30%, greatly reduce the weight of the mold and shorten the grinding and polishing time by half. 4、 Innovation power In order to strengthen the competitiveness, the production of foreign die steel tends to be centralized from decentralized, and many companies have conducted transnational mergers. In order to better compete, these companies have built complete and technologically advanced die steel production lines and die steel scientific research bases, and formed several world-famous die production and research centers to meet the rapid development of the die industry. Editor's note: the mold industry is a modern process base material and an industry relying on technology and quality. Only by strengthening research and development can we be invincible in the industry. At present, there is still a certain gap between the domestic mold industry and foreign counterparts. However, as long as we quickly absorb foreign advanced technology and constantly try to improve and innovate, we will certainly make great breakthroughs in the near future.

The same is true in the plastic industry. The hardness, wear resistance, toughness, cracking resistance, collapse angle resistance, corrosion resistance and processing accuracy of plastic molds make them very popular. So, what is the future development trend of plastic mold? 1、 High quality The development trend of die steel in Europe and America is that carbon tool steel, low alloy tool steel and high alloy tool steel have successively appeared a series of new die materials, and the alloying degree of die standard steel is also increasing. 1. Development trend of new plastic die steel abroad Plastic mold steel with good free cutting and polishing properties, such as 412 and M-300 of the United States, YAG of Japan, EAB of the United Kingdom, stavax-13 of Sweden, etc; Pre hardened plastic die steel, such as P20 and 445 in the United States, PDS in Japan, movtrex-a (2312) in Germany, etc; Integrally hardened plastic die steel, such as A2, D3 and H13 in the United States; Corrosion resistant plastic die steel, such as 110cr-mo17 in the national standard ISO and 4Cr13 in the Swedish Assab company. 2. Advanced die surface treatment technology The surface of die was treated by multi-element infiltration and compound infiltration instead of single element infiltration. The coating on the mold surface can be tic, tin, TiCN, TiAlN, CrN, Cr7C3, W2C, etc. the coating can be prepared by physical vapor deposition, chemical vapor deposition, physical chemical vapor deposition, ion penetration, ion implantation and other methods. 2、 High accuracy The high-speed scanner and the mold scanning system provide many functions required from the model or the physical object scanning to the processing of the desired model, greatly shortening the mold development and manufacturing cycle. The mold scanning system has been successfully applied in the European and American mold industry. The equipment in this respect, such as the high-speed scanner (cyclonseries 2) of Renishaw company, can realize the complementary advantages of the laser probe and the contact probe. The laser scanning accuracy is 0.05mm and the contact probe scanning accuracy is 0.02mm. 3、 High efficiency 1. High speed cutting technology is widely used It is generally used for large-scale panel dies, and its surface processing accuracy can reach 0.01mm. After high-speed milling and finishing, the mold surface can be used only with a little polishing, saving a lot of time for grinding and polishing. High speed machining greatly shortens the mold making cycle, thus improving the market competitiveness of products. 2. Combination of rapid prototyping technology and rapid tooling technology The combination of rapid prototyping technology and rapid tooling technology is applied to mold manufacturing, that is, the prototype of product parts is manufactured by rapid prototyping technology, and then the mold is rapidly manufactured based on the prototype. The cost of using this technology from mold design to manufacturing is only 1 / 3 of that of traditional methods. The rapid prototype casting silicone rubber mold is used for turning a small number of plastic parts, which is very suitable for the trial production of products. The injection mold made of aluminum can shorten the injection cycle by 25-30%, greatly reduce the weight of the mold and shorten the grinding and polishing time by half. 4、 Innovation power In order to strengthen the competitiveness, the production of foreign die steel tends to be centralized from decentralized, and many companies have conducted transnational mergers. In order to better compete, these companies have built complete and technologically advanced die steel production lines and die steel scientific research bases, and formed several world-famous die production and research centers to meet the rapid development of the die industry. Editor's note: the mold industry is a modern process base material and an industry relying on technology and quality. Only by strengthening research and development can we be invincible in the industry. At present, there is still a certain gap between the domestic mold industry and foreign counterparts. However, as long as we quickly absorb foreign advanced technology and constantly try to improve and innovate, we will certainly make great breakthroughs in the near future.

With the expansion of production scale and global industrial transfer of automobile and parts, aerospace, mold, railway transportation equipment, construction machinery and other equipment manufacturing industries, as well as the strong demand of related industries for multi-level machine tool products, China's metal cutting machine tool manufacturing industry is facing an accelerated period of development. In the first half of this year, the overall development of China's manufacturing industry recovered, the intelligent upgrading continued to advance, and the robot and automation equipment maintained a high prosperity. According to the data of the National Bureau of statistics, from January to June, the cumulative output of domestic industrial robots reached 59000, with a year-on-year increase of 52%. In June, the year-on-year increase reached 61%, ranking the first among various industrial products; From January to June, the cumulative output of metal cutting machine tools reached 400000, with a year-on-year increase of 8.7%. Metal cutting machine tool industry metal cutting machine tools are the most widely used and the largest number of machine tools. Affected by the recovery of the machine tool market demand since 2016, the production capacity of China's metal cutting machine tool industry has been increasing. With the expansion of production scale and global industrial transfer of automobile and parts, aerospace, mold, railway transportation equipment, construction machinery and other equipment manufacturing industries, as well as the strong demand of related industries for multi-level machine tool products, China's metal cutting machine tool manufacturing industry is facing an accelerated period of development. 8195, It plays an important basic supporting role in the process of China's transformation from a manufacturing power to a manufacturing power. Industrial robot in recent years, China has promoted the transformation and upgrading of the manufacturing industry, and the output of industrial robots has increased significantly. Manufacturing enterprises have used industrial robots on a large scale, which has improved the production level and efficiency of the manufacturing industry. On this basis, the manufacturing industry continues to introduce advanced technologies of artificial intelligence, making the manufacturing industry move towards intelligent manufacturing. At the same time, more cutting-edge technologies, such as visual perception, big data, cloud computing and other artificial intelligence technologies have also started to "follow up" in a timely manner. Technology integration is creating more profound industrial changes. This is exactly the scenario that the transformation and upgrading of the manufacturing industry wants to achieve, that is, from automation to intelligence, benchmarking German industry 4.0. 8195. It is with the help of artificial intelligence, a new technology, that manufacturing industry has gradually changed from automation to intelligence. As the "pearl in the crown of manufacturing industry", industrial robots gradually reflect their own value in the process of the development of China's manufacturing industry. The booming industrial robot application market has also attracted a large number of industrial robot enterprises such as Dalian machine tool and Huazhong CNC to settle in Guangdong, and has also pushed China's industrial robot market to a new height.

With the expansion of production scale and global industrial transfer of automobile and parts, aerospace, mold, railway transportation equipment, construction machinery and other equipment manufacturing industries, as well as the strong demand of related industries for multi-level machine tool products, China's metal cutting machine tool manufacturing industry is facing an accelerated period of development. In the first half of this year, the overall development of China's manufacturing industry recovered, the intelligent upgrading continued to advance, and the robot and automation equipment maintained a high prosperity. According to the data of the National Bureau of statistics, from January to June, the cumulative output of domestic industrial robots reached 59000, with a year-on-year increase of 52%. In June, the year-on-year increase reached 61%, ranking the first among various industrial products; From January to June, the cumulative output of metal cutting machine tools reached 400000, with a year-on-year increase of 8.7%. Metal cutting machine tool industry metal cutting machine tools are the most widely used and the largest number of machine tools. Affected by the recovery of the machine tool market demand since 2016, the production capacity of China's metal cutting machine tool industry has been increasing. With the expansion of production scale and global industrial transfer of automobile and parts, aerospace, mold, railway transportation equipment, construction machinery and other equipment manufacturing industries, as well as the strong demand of related industries for multi-level machine tool products, China's metal cutting machine tool manufacturing industry is facing an accelerated period of development. 8195, It plays an important basic supporting role in the process of China's transformation from a manufacturing power to a manufacturing power. Industrial robot in recent years, China has promoted the transformation and upgrading of the manufacturing industry, and the output of industrial robots has increased significantly. Manufacturing enterprises have used industrial robots on a large scale, which has improved the production level and efficiency of the manufacturing industry. On this basis, the manufacturing industry continues to introduce advanced technologies of artificial intelligence, making the manufacturing industry move towards intelligent manufacturing. At the same time, more cutting-edge technologies, such as visual perception, big data, cloud computing and other artificial intelligence technologies have also started to "follow up" in a timely manner. Technology integration is creating more profound industrial changes. This is exactly the scenario that the transformation and upgrading of the manufacturing industry wants to achieve, that is, from automation to intelligence, benchmarking German industry 4.0. 8195. It is with the help of artificial intelligence, a new technology, that manufacturing industry has gradually changed from automation to intelligence. As the "pearl in the crown of manufacturing industry", industrial robots gradually reflect their own value in the process of the development of China's manufacturing industry. The booming industrial robot application market has also attracted a large number of industrial robot enterprises such as Dalian machine tool and Huazhong CNC to settle in Guangdong, and has also pushed China's industrial robot market to a new height.

To select metal cutting fluid, it is first necessary to select pure oil-based metal cutting fluid or water-soluble metal cutting fluid according to the process conditions and requirements of cutting. Usually we can choose according to the recommendation of the machine tool supplier; Secondly, it can also be selected according to conventional experience. For example, when high-speed steel tools are used for low-speed cutting, pure oil-based metal cutting fluid is usually used; when hard alloy tools are used for high-speed cutting, water-soluble metal cutting fluid is usually used; Pure oil-based metal cutting fluid (such as tapping, broaching of inner holes, etc.) is used when it is difficult to supply fluid or the cutting fluid is not easy to reach the cutting area. In other cases, water-soluble metal cutting fluid can be used. In short, the specific cutting fluid type shall be selected according to the specific cutting conditions and requirements, the different characteristics of pure oil-based metal cutting fluid and water-soluble metal cutting fluid, and the different actual conditions of each plant, such as the ventilation conditions of the workshop, the waste liquid treatment capacity and the use of cutting fluid in the previous and subsequent processes. Secondly, after selecting the type of cutting fluid, the type of cutting fluid should be preliminarily selected according to the cutting process, the material of the workpiece and the requirements for the machining accuracy and roughness of the workpiece. For example, when selecting the cutting fluid for grinding, we should not only consider the conditions of ordinary cutting, but also consider the characteristics of the grinding process itself: we all know that the grinding process is actually a Multi Tool simultaneous cutting process. The feed amount of grinding is small and the cutting force is usually small, but the grinding speed is high (30-80m / s). Therefore, the temperature in the grinding area is usually high, up to 800-1000 ℃, It is easy to cause local burns on the surface of the workpiece, and the thermal stress of grinding will cause deformation of the workpiece and even crack on the surface of the workpiece. At the same time, a large amount of metal grinding debris and grinding wheel dust will be produced in the grinding process, which will affect the surface roughness of the workpiece; Therefore, when selecting the water-soluble metal cutting fluid for grinding, we need the cutting fluid to have good cooling, lubrication and washing and scouring properties. According to the different materials of workpieces, when selecting water-soluble metal cutting fluid, different cutting fluid products should be selected according to the different characteristics of different materials. For example, when cutting high hardness stainless steel, the extreme pressure water-soluble metal cutting fluid with good extreme pressure performance should be selected according to its characteristics of high hardness, high strength and difficult cutting, so as to meet the extreme pressure lubrication performance requirements of the cutting fluid in the cutting process; For materials such as aluminum alloy and copper alloy, due to the characteristics of high toughness and high activity of the material itself, when selecting water-soluble metal cutting fluid, the lubricity and cleaning property of the cutting fluid are required, and the workpiece cannot be corroded.

1、 When finishing turning the outer circle, there are chaotic ripples on the circumferential surface Cause: 1. The raceway of the main shaft rolling bearing is worn. 2. The axial clearance of the main shaft is too large. 3. When the tailstock is used to support the workpiece cutting, the center sleeve is unstable. 4. When the chuck is used to clamp the workpiece for cutting, the internal thread of the chuck flange hole and the thread of the centering journal at the front end of the main shaft are loose, which causes the workpiece to be unstable, or the jaw is in the shape of a horn hole, which causes the workpiece to be clamped unstable. 5. The square tool rest is deformed due to clamping the tool, resulting in poor contact between the ground and the bottom plate of the upper tool rest. 6. The clearance between the sliding surfaces of the upper and lower tool holders (including the carriage) is too large. 7. The three support shafts of the tool box and the carriage box bracket are different, and the rotation is restrained (jamming phenomenon). resolvent: 1. Replace the rolling bearing of the main shaft. 2. Adjust the clearance of the thrust ball bearing at the rear end of the main shaft. 3. Check the tailstock center sleeve, shaft hole and clamping device. If it fails to work, repair the shaft hole first. 4. Change the clamping method of the workpiece and use the tailstock to support cutting. 5. Scrape and repair the joint surface of the base plate of the square tool rest to achieve uniform and comprehensive contact. 6. Adjust the iron stopper pressing plates of all guide rail pairs to make them fit evenly and shake smoothly and easily. 7. Check the supports and remove and reassemble them if necessary. 2、 Finish turning the outer circular surface, with repeated corrugations every certain length Cause: 1. The longitudinal cutter pinion of the carriage box is not meshed with the rack normally. 2. The smooth rod is bent or the mounting holes of the smooth rod, screw rod and tool walking rod are not on the same plane. 3. One of the transmission gears in the carriage box may be damaged, or the kneading caused by pitch diameter vibration is incorrect. 4. The shaft in the headstock and tool box is bent or the gear is damaged. Solution: 1. Adjust the meshing clearance and make the gear rack mesh on the full width of the tooth surface. 2. The polished rod shall be removed and straightened; During assembly, keep the three holes coaxial and on the same plane. 3. Check and correct the transmission gear in the carriage box, and replace it if damaged. 4. Check the transmission shaft and gear, straighten the transmission shaft and replace the damaged gear. 3、 The outer diameter taper of cylindrical workpiece after machining is out of tolerance Cause: 1. The unevenness of the headstock main shaft centerline to the moving guide rail of the slide plate is out of tolerance. 2. The inclination of the bed guide rail is out of tolerance or deformed after assembly. 3. The guide rail surface of the bed is seriously worn, and the straightness in the horizontal plane when the slide plate moves and the inclination when the slide plate moves are out of tolerance. 4. Because the center line of the spindle taper hole and the center line of the tailstock center sleeve taper hole are not on the same straight line. 5. The blade is not wear-resistant. 6. The temperature rise of the headstock is too high, causing the thermal deformation of the machine tool: the friction heat generated by the movement is absorbed by the lubricating oil and becomes a large secondary heat source. The heat is transmitted from the bottom of the headstock to the bed and the headstock, causing the temperature of the joint part of the bed to rise and expand, causing the thermal deformation of the machine tool. resolvent: 1. Re calibrate the installation position of the headstock spindle center line to make the workpiece within the allowable error range. 2. Readjust the inclination of the bed guide rail with the adjusting shim. 3. If the straightness of the slide plate moving in the horizontal plane and the inclination of the slide plate moving are small, the guide rail surface is free of large-area scratches and can be repaired by scraping the guide rail. 4. Adjust the screws on both sides of the tailstock to eliminate the taper. 5. Trim the tool and select the spindle speed and feed rate correctly. 6. Properly adjust the oil supply quantity of the lubricating oil of the front bearing of the main shaft, replace the appropriate lubricating oil, and check whether the oil supply quantity of the oil pump is blocked. 4、 After finishing turning, the end face of the workpiece is convex Cause: 1. The non parallelism of the center line of the headstock spindle caused by the movement of the slide plate is poor. 2. The upper and lower guide rails of the slide are not vertical. resolvent: 1. Correct the position of the spindle center line of the headstock. On the premise of ensuring that the positive cone of the workpiece is qualified, the spindle center line will deviate forward, that is, to the tool rest. 2. Scrape and grind the guide rail surface of the slide plate, and make the outer end of the upper guide rail of the slide plate deviate to the headbox. 5、 When turning thread, the pitch is uneven and the thread is disordered Cause: 1. The screw rod of the machine tool is worn and bent, the opening and closing nut is worn and the screw rod is different from the shaft, and the engagement is poor. The clearance is too large, and the opening and closing nut is unstable when it is closed due to the wear of the dovetail guide rail. 2. The clearance of the transmission chain from the main shaft through the change gear is too large. 3. The axial clearance of the screw rod is too large. 4. The male and British system handles are wrong, the fork position is wrong, or the change gear on the change gear frame is wrong. resolvent: 1. Straighten the screw rod, adjust the clearance between the screw rod and the split nut pair, and scrape the dovetail guide rail to ensure the stability of the split nut when it is closed. 2. Check the meshing clearance of all transmission parts, and adjust all adjustable ones, such as change gears. 3. Adjust the axial clearance and play of the screw rod. 4. Check whether the handle, fork and change wheel are correct, and correct them if wrong. 6、 Ellipse or edge circle produced by workpiece Cause: 1. The clearance of main shaft bearing is too large. 2. The ellipse of the main shaft journal is too large. 3. The main shaft bearing is worn, or the accuracy of the final gear of the main shaft is out of tolerance, and there is vibration during rotation. 4. The outer diameter of the main shaft bearing sleeve is elliptical or the shaft hole of the headstock box is elliptical, or the fitting clearance between the two is too large. 5. The thimble tip of the machine tool is worn off, or the thimble hole of the workpiece is not round. Solution: 1. Adjust the clearance of main shaft bearing; If the lathe works at high speed, the adjusted clearance should be slightly larger; if it works at low speed, the clearance should be smaller. If the spindle clearance is adjusted according to the low speed, the phenomenon of holding the spindle may occur in the high-speed operation. Therefore, the speed range shall be adjusted according to the daily use specification of the lathe, and the general clearance shall be between 0.02 and 0.04 mm. 2. The Journal of the main shaft is polished to meet the requirements of roundness. 3. Scrape the bearing and replace the rolling bearing or the final gear. 4. If the out of roundness of the shaft hole is particularly poor, it shall be scraped round and straight first, and then repaired by "local nickel plating"; If it is a sliding bearing, it must be replaced with a new bearing sleeve. 5. Repair the ejector pin or workpiece ejector pin hole.

We all know that deep hole processing is not easy to do. We have talked about the problem of hole diameter reduction in deep hole processing. In the spirit of truth-seeking, the editor seriously consulted the senior engineer of quick screening: the following is the reason analyzed by Master Liu. Cause: The design value of reamer outer diameter is too small; The cutting speed is too low; The feed amount is too large; The main deflection angle of reamer is too small; Improper selection of cutting fluid; The worn part of reamer is not worn out during grinding, and the elastic recovery reduces the aperture; When reaming steel parts, if the allowance is too large or the reamer is not sharp, it is easy to produce elastic recovery, so that the aperture is reduced, the inner hole is not round, and the aperture is unqualified. Solution Replace the outer diameter of reamer; Properly increase the cutting speed; Appropriately reduce the feed rate; Increase the main deflection angle appropriately; Select oil-based cutting fluid with good lubricating performance; Regularly exchange reamers and properly sharpen the cutting parts of reamers; When designing reamer size, the above factors shall be considered or the value shall be taken according to the actual situation; Make experimental cutting, take appropriate allowance and sharpen reamer.