Double-sided local electronic electroplating method, and double-sided cleaning device and double-sided electronic electroplating mold used in double-sided local electronic electroplating method

Abstract

The invention relates to a double-sided local electronic electroplating method and a double-sided cleaning device and a double-sided electronic electroplating mold used in the method, and belongs to the technical field of double-sided local semiconductor electronic electroplating. The method comprises the following steps: after pre-treating a semiconductor device, sequentially performing first-time plating piece washing, double-sided local plating of a bottom layer metal film, second-time plating piece washing, plating piece pickling, third-time plating piece washing, double-sided local plating of noble metal and fourth-time plating piece washing; wherein the double-sided local plating of the bottom layer metal film and the double-sided local plating of the noble metal are both subjected to double-sided local electroplating treatment by using a double-sided electronic electroplating mold. According to the invention, the pollution of the residual noble metal electroplating solution on the surface of the mold silica gel to semiconductor devices and the replacement reaction between metals are avoided, and the excellent binding force between the noble metal plating layer and the bottom plating metal layer of the continuously produced electronic electroplating device is maintained.

Description

Technical Field

[0001] The invention relates to a double-sided local electronic electroplating method and a double-sided cleaning device and a double-sided electronic electroplating mold used therein, belonging to the technical field of double-sided local semiconductor electronic electroplating. Background Art Electronic electroplating forms a metal coating on the plated part by the principle of cathode electrolytic reduction. It is a special manufacturing technology for nano-precision manufacturing of semiconductor devices. Its application areas include semiconductor wafer electroplating, printed circuit board electroplating, lead frame electroplating, connector electroplating, microwave devices and other electronic components manufacturing. It is the only key technology that can achieve nano-level electronic logic interconnection and micro-nano structure manufacturing and processing. Electronic electroplating has become a basic, universal and irreplaceable special manufacturing technology in the production of high-end electronic products such as wafer chip manufacturing, three-dimensional integration and device packaging, micro-nano device manufacturing, micro-electromechanical systems, sensors, components, etc. in the semiconductor integrated industry chain.

[0002] In order to make the semiconductor electronic components have reliable and excellent performance, the metal coating formed on the surface of the plated parts needs to have high uniformity, excellent density and strong corrosion resistance in various harsh environments, and can be used for efficient electronic plating equipment and methods for plated parts of various complex shapes. Among them, the double-sided local electronic plating method is an important basis for electronic plating of semiconductor devices.

[0003] With the rapid development of science and technology, the components of semiconductor integrated circuits required by the new energy industry are constantly being updated, and the technical requirements for high-end manufacturing of electronic electroplating are becoming higher and higher. In particular, with the rapid rise of new energy vehicles in recent years, a variety of new performance electronic components are emerging in an endless stream, and the use of conventional electroplating equipment and electroplating methods can no longer meet the performance requirements of new energy electronic components. For example, more and more semiconductor components are limited to local electroplating treatment for the area that transmits signals, while areas with heat dissipation and other functions do not require any electroplating treatment; in the present invention, in order to ensure the heat dissipation function of semiconductor devices, the area of ​​the heat sink is usually quite different from the local electroplating area of ​​the transmission signal, which is several times or dozens of times higher.

[0004] In the prior art, CN100514759A adopts a process method including nickel / gold plating on plated parts, and a technical solution of bottom nickel plating to prevent the copper material of the plated parts from being oxidized; CN114892225A includes a method for electroplating gold on a nickel coating, and provides a plating solution for electroplating gold on a nickel coating, a method for electroplating gold on a nickel coating, and an application of gold-plated parts; CN102131962A adopts a hard gold plating solution including a soluble gold salt conductive salt and a chelating agent; GB1461474A adopts a method of co-depositing cadmium, tin, antimony or cobalt in the electroplating process using a cyanide plating solution to improve the hardness of the gold coating, thereby improving the wear resistance of the coating; CN117552063A adopts a cyanide-free gold plating solution to reduce the nickel-gold replacement problem that occurs during the gold plating process on the nickel layer, reduce the generation of the replacement gold coating, and improve the bonding force between the nickel layer and the gold layer, thereby improving the reliability of the device; CN 117779130 A uses tungsten nickel / gold plating to make the tungsten nickel / gold plating deposited in the plating area of ​​the semiconductor device have a dense amorphous morphology, no pinholes, no gaps, and a smooth surface. In summary, the existing electroplating process methods are all to implement gold plating on the surface of the electronic component copper material under the premise of electroplating the underlying metal plating layer to protect it from oxidation.

[0005] However, as more and more semiconductor integrated circuit products only need to be locally electroplated in the area where signals are transmitted, the use of existing electroplating process production lines for semiconductor integrated circuit products that only need to be electroplated in the area where signals are transmitted often causes the following problems to occur on the surface of the copper material in the non-plated area: 1) substitution reactions with other metals in the electroplating solution, resulting in product defects; 2) oxidation reactions with oxidizing substances in the ambient atmosphere, resulting in performance defects of semiconductor electronic components. Specific defects include: Figure 7a and Figure 7b The white spots on the copper surface shown, Figure 8a and Figure 8b The copper surface color difference shown; these deficiencies result in the existing electroplating process production line being unable to meet the development needs of electronic electroplating of semiconductor integrated circuit products that only need to be electroplated in the area transmitting signals.

[0006] In summary, in the field of electronic electroplating of electronic products in the semiconductor integrated circuit industry chain, the existing electroplating technology uses a method of pre-plating the underlying metal on the entire semiconductor device and then electroplating precious metals in local areas, which is no longer suitable for the electroplating of new semiconductor devices. Therefore, it is urgent to find an effective double-sided local electronic electroplating treatment method to solve the problems of metal replacement and copper oxidation on the copper surface of electronic components; in order to obtain excellent uniform distribution, morphology, purity and density through electronic electroplating equipment to meet the market demand for the production of semiconductor integrated circuit electronic products with high corrosion resistance, high-precision conductivity and high-quality electronic signal transmission performance.

[0007] There are no literature reports on the solutions to the above-mentioned problems. The existence of these scientific problems and technical difficulties in the field of electronic electroplating technology has hindered the growing demand for innovative high-end electronic components and materials in the aerospace, new energy vehicle, and communications electronics industries, and is a research topic that urgently needs innovative breakthroughs. Summary of the invention

[0008] As shown in Table 1, the existing electroplating process technology is used for double-sided local electroplating. There are white spots, color difference and dirt missing on the copper surface of the non-plated area of ​​the semiconductor device; and there are fatal defects such as nickel plating copper leakage, gold plating dirt and poor plating adhesion in the local plating area. These defects directly lead to the decline of semiconductor device product performance, especially the lack of plating adhesion will make the semiconductor device become waste.

[0009] Table 1

[0010] The present invention provides a double-sided local electronic electroplating method to solve the problems of metal replacement and copper oxidation on the copper surface of semiconductor devices. The method can be applied to nano-precision manufacturing and processing of semiconductor integrated circuit electronic products, and the formed double-sided local electronic electroplating gold film has excellent uniform distribution, morphology, purity and density, and obtains high corrosion resistance and high-precision conductivity. At the same time, the electronic electroplating process and the electronic electroplating method of the present invention can ensure the design functions such as heat dissipation of metal materials in non-plated areas, thereby providing the semiconductor integrated circuit industry with a variety of high-end precision semiconductor integrated circuit electronic products with high-quality electronic signal transmission performance.

[0011] On the one hand, the present invention aims to solve the problems of white spots, color difference and dirt on the copper surface of the non-plated area of ​​semiconductor devices in the existing electroplating technology by improving the function of the cleaning process tank and adding filtering measures; on the other hand, by optimizing the pre-treatment process, optimizing the treatment liquid filtration and the gold plating post-treatment process and optimizing the acid activation treatment process conditions before electroplating, the problems of nickel plating copper leakage, gold plating dirt and poor bonding in the plating area of ​​semiconductor devices in the existing electroplating technology are solved.

[0012] The present invention provides a double-sided local electronic electroplating method, which performs a first water washing of the plated part, a double-sided local metal film plating of the bottom layer, a second water washing of the plated part, an acid washing of the plated part, a third water washing of the plated part, a double-sided local precious metal plating and a fourth water washing of the plated part after pre-processing the semiconductor device; wherein the double-sided local metal film plating and the double-sided local precious metal plating are both performed by using a double-sided electronic electroplating mold for double-sided local electroplating; The process of double-sided local plating of bottom metal film and double-sided local plating of precious metal respectively includes a primary mold circulation process for the double-sided electronic electroplating mold and a secondary mold circulation process for the double-sided electronic electroplating mold; the primary mold circulation process and the secondary mold circulation process are both configured to cyclically perform mold washing, mold drying, mold standby, semiconductor devices are arranged in the mold and then assembled in the electronic electroplating device, so as to clean the electroplating solution remaining in the mold so that the electroplating solution isolates the copper surface of the semiconductor device; The first plated parts water washing, the first mold circulation process, the second plated parts water washing, the plated parts pickling, the third plated parts water washing, the second mold circulation process and the fourth plated parts water washing are all cleaned by a double-sided cleaning device, and the double-sided cleaning device includes a first-level water tank unit, a second-level water tank unit, and a third-level water tank unit connected in sequence. When the first-level water tank unit is equipped with a quantitative pure water replenishment pipeline, the water in the first-level water tank unit will overflow step by step to the second-level water tank unit and the third-level water tank unit after accumulation, forming a step-by-step overflow structure.

[0013] Furthermore, the first-level water tank unit includes an upper pump, an upper diverter plate, an upper water outlet baffle, a lower water outlet baffle, a lower diverter plate, and a lower pump, which are arranged in sequence from top to bottom. A cavity is arranged between the upper water outlet baffle and the lower water outlet baffle, and the cavity is used to place semiconductor devices or double-sided electronic electroplating molds. The structures of the first-level water tank unit, the second-level water tank unit, and the third-level water tank unit are exactly the same.

[0014] Preferably, the distance from the semiconductor device / double-sided electronic electroplating mold to the upper water outlet baffle is set to 50 mm, and the distance from the semiconductor device / double-sided electronic electroplating mold to the lower water outlet baffle is set to 35 mm.

[0015] Preferably, the upper water outlet baffle is provided with a plurality of upper water outlets, and the lower water outlet baffle is provided with a plurality of lower water outlets, and the water outlet angles of the upper water outlets and the lower water outlets are both set to 70 degrees.

[0016] Preferably, the diameter of the upper water outlet and the diameter of the lower water outlet are set to 6.0 mm and 4.5 mm respectively.

[0017] Preferably, the frequencies of the upper pump and the lower pump are set to 50 Hz and 40 Hz respectively, and the cleaning time for each cleaning is set to 15 seconds.

[0018] Furthermore, the double-sided electronic electroplating mold includes an upper shell, an anode, an upper silicone mask, a lower silicone mask, an anode, and a lower shell arranged in sequence from top to bottom, and a gap is left between the upper silicone mask and the lower silicone mask, and the gap is used to fix the semiconductor device.

[0019] Preferably, 10.0A / dm is used in the process of double-sided local plating of the bottom metal film and double-sided local plating of the precious metal. 2 The current density is set to 0.58A, the bath temperature is set to 50°C, and a high-speed jet precision electronic electroplating equipment is used. A double pulse power supply is used to energize the semiconductor device to be plated for 23 seconds. Both the upper silicone mask and the lower silicone mask have inlay grooves adapted to semiconductor devices.

[0020] A double-sided local electronic electroplating method of the present invention can perform local electroplating treatment only in the area where signals are transmitted, and can prevent various situations that occur on the surface of copper materials in non-plated areas caused by existing electroplating methods: 1) substitution reaction with metals in other electroplating solutions resulting in poor products, and 2) oxidation reaction with oxygen in the ambient atmosphere resulting in performance loss of electronic components.

[0021] Beneficial effects of the present invention: The present invention uses a double-sided local electronic electroplating method to successively clean semiconductor devices multiple times and perform double-sided electroplating and synchronous cycle cleaning of the mold, thereby preventing the pollution of semiconductor devices by the residual precious metal electroplating solution on the surface of the mold silicone and the replacement reaction between metals, maintaining the excellent bonding force between the precious metal coating and the bottom plated metal layer of the continuously produced electronic electroplating devices, and finally realizing a precious metal coating with nano-level dense morphology, uniform distribution, extremely high purity and excellent density, and obtaining a double-sided local semiconductor device electronic electroplating product with a dense precious metal coating, uniform film thickness distribution and high purity.

[0022] At the same time, by adopting a double-sided local electronic electroplating device that can quickly disassemble the electroplating mold and configuring a special mold washing process flow, the mold is thoroughly cleaned after each electroplating and dried for use; through the processing of this process flow, the electroplating solution remaining in the electroplating mold during each electroplating process is thoroughly cleaned in the mold washing process, and the mold is maintained to its initial state by drying; it is ensured that during the production process, each semiconductor device is set in a clean and dry electroplating mold to prevent the residual electroplating solution from contacting the copper surface of the semiconductor device, and to prevent white spots and color differences on the product surface caused by contamination by various chemical components in the electroplating solution; the prepared semiconductor device non-plating area heat sink field meets its unique performance requirements, and the bottom-plating metal film in the double-sided local electroplating area has excellent bonding with the semiconductor device material; the bottom-plating metal film thus formed has excellent morphology, uniform distribution and excellent density, and the produced semiconductor device electronic products have excellent corrosion resistance, high-precision conductivity and high-quality electronic signal transmission performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1The present invention is an overall operation flow chart of a double-sided local electronic electroplating method in one embodiment of the present invention.

[0024] Figure 2 It is a schematic structural diagram of a double-sided cleaning device in one embodiment of the present invention.

[0025] Figure 3 It is a schematic structural diagram of a semiconductor device in one embodiment of the present invention.

[0026] Figure 4 It is a schematic structural diagram of a primary water tank unit in one embodiment of the present invention.

[0027] Figure 5 It is a schematic diagram of a double-sided cleaning device in a CFD space model according to one embodiment of the present invention.

[0028] Figure 6 It is a schematic structural diagram of a double-sided electronic electroplating mold in one embodiment of the present invention.

[0029] Figure 7a and Figure 7b The white spot pattern images appearing in two comparative examples of the present invention are shown in FIG.

[0030] Figure 8a and Figure 8b These are the color difference samples that appear in two comparative examples of the present invention.

[0031] Figure 9a and Figure 9b This is a sample diagram of color difference occurring in Examples 1 and 2 of the present invention.

[0032] Fig.10a , Fig.10b , Fig.10c , Fig.10d This is a sample diagram of color difference that occurs in Examples 3-6 of the present invention.

[0033] In the figure, 100, double-sided local electronic plating method; 110, double-sided local plating of bottom metal film; 120, double-sided local plating of precious metal; 13. Double-sided cleaning device; 131. Primary water tank unit; 132. Secondary water tank unit; 133. Third-level water tank unit; 20. semiconductor device; 21. heat sink; 22. double-sided electronic plating area; 210. upper pump; 220. upper manifold; 230. upper water outlet baffle; 330. lower water outlet baffle; 320. lower manifold; 310. lower pump; 121, upper silicone mask; 122, upper anode; 123, upper shell; 124, lower silicone mask; 125, lower anode; 126, lower shell; Y Vertical distance from the upper water outlet baffle to the semiconductor device Z The vertical distance from the lower water outlet baffle to the semiconductor device d Upper water outlet diameter ΦLower water outlet diameter δThe angle between the upper outlet and the upper outlet baffle plane α is the angle between the lower water outlet and the plane of the lower water outlet baffle. DETAILED DESCRIPTION

[0034] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0035] In the present invention, unless otherwise clearly specified and limited, the terms "connected", "connected", and "fixed" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0036] In the present invention, the "first" and "second" are only used to distinguish similar components / parts with different positions or different characteristics, and have no other limiting meanings; the "upper" refers to the direction of each component away from the ground, and the "lower" refers to the direction of each component away from the ground.

[0037] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may include that the first and second features are in direct contact, or may include that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, a first feature being "above", "above" and "above" a second feature includes that the first feature is directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. A first feature being "below", "below" and "below" a second feature includes that the first feature is directly below and obliquely below the second feature, or simply indicates that the first feature is lower in level than the second feature.

[0038] The present invention provides a double-sided local electronic electroplating method to solve the problems of metal replacement and copper oxidation on the copper surface of semiconductor devices. The method can be applied to nano-precision manufacturing and processing of semiconductor integrated circuit electronic products, and the formed double-sided local electronic electroplating gold film has excellent uniform distribution, morphology, purity and density, and obtains high corrosion resistance and high-precision conductivity. At the same time, the electronic electroplating process and the electronic electroplating method of the present invention can ensure the design functions such as heat dissipation of metal materials in non-plated areas, thereby providing the semiconductor integrated circuit industry with a variety of high-end precision semiconductor integrated circuit electronic products with high-quality electronic signal transmission performance.

[0039] On the one hand, the present invention aims to solve the problems of white spots, color difference and dirt on the copper surface of the non-plated area of ​​semiconductor devices in the existing electroplating technology by improving the function of the cleaning process tank and adding filtering measures; on the other hand, by optimizing the pre-treatment process, optimizing the treatment liquid filtration and the gold plating post-treatment process and optimizing the acid activation treatment process conditions before electroplating, the problems of nickel plating copper leakage, gold plating dirt and poor bonding in the plating area of ​​semiconductor devices in the existing electroplating technology are solved.

[0040] like Figure 1 As shown, the present invention provides a double-sided local electronic electroplating method, which performs a first water washing of the plated part, a double-sided local bottom metal film plating, a second water washing of the plated part, a pickling of the plated part, a third water washing of the plated part, a double-sided local precious metal plating and a fourth water washing of the plated part in sequence after pre-processing the semiconductor device; wherein the double-sided local bottom metal film plating and the double-sided local precious metal plating are both subjected to double-sided local electroplating treatment using a double-sided electronic electroplating mold; Specifically, the above steps are introduced: First, pretreatment is performed, which includes ultrasonic degreasing, electrolytic degreasing, pickling and acid activation; After the semiconductor device 20 has been pre-treated, a double-sided electronic plating mold is used to locally plate the bottom metal film on both sides. The nickel film thickness specification requires 1500nm. The current density during electronic plating is 7.0A / dm 2 , then the current is set to 0.41A, the bath temperature is set to 50°C, and then the high-speed jet precision electroplating equipment is used, using a pulse power supply, and the plated parts are energized for 57 seconds; Next, the semiconductor device product is quickly taken out from the double-sided electronic electroplating mold, and the upper and lower parts of the double-sided electronic electroplating mold are quickly disassembled to successively perform the second plating part water washing, the plating part acid washing, and the third plating part water washing; Then, a double-sided electronic plating mold is used to locally plate precious metals on both sides. The thickness of nickel and gold is required to be ≥100nm. The current density during electronic plating is 10.0A / dm 2, then set the current to 0.58A, the bath temperature to 50°C, and then use high-speed jet precision electronic electroplating equipment and a double-pulse power supply to energize the plated parts for 23 seconds; Finally, after quickly taking out the semiconductor device product, the upper and lower parts of the double-sided electronic electroplating mold are quickly disassembled and the plated parts are washed for the fourth time.

[0041] Furthermore, if Figure 6 As shown, the double-sided electronic electroplating mold includes an upper shell 123, an upper anode 122, an upper silicone mask 121, a lower silicone mask 124, a lower anode 125, and a lower shell 126 arranged in sequence from top to bottom, and a gap is left between the upper silicone mask 121 and the lower silicone mask 124, and the gap is used to fix the semiconductor device 20.

[0042] The upper part of the double-sided electronic plating mold includes an upper shell 123 , an upper anode 122 , and an upper silicone mask 121 ; the lower part of the double-sided electronic plating mold includes a lower silicone mask 124 , a lower anode 125 , and a lower shell 126 .

[0043] The process of double-sided local plating of bottom metal film and double-sided local plating of precious metal respectively includes a primary mold circulation process for the double-sided electronic electroplating mold and a secondary mold circulation process for the double-sided electronic electroplating mold; the primary mold circulation process and the secondary mold circulation process are both configured to cyclically perform mold washing, mold drying, mold standby, semiconductor devices are arranged in the mold and then assembled in the electronic electroplating device, so as to clean the electroplating solution remaining in the mold so that the electroplating solution isolates the copper surface of the semiconductor device; The first plated part washing, the first mold circulation process, the second plated part washing, the plated part pickling, the third plated part washing, the second mold circulation process and the fourth plated part washing are all cleaned by a double-sided cleaning device, such as Figure 2 As shown, the double-sided cleaning device 13 includes a primary water tank unit 131, a secondary water tank unit 132, and a tertiary water tank unit 133 which are connected in sequence. When the electronic electroplating device / double-sided electronic electroplating mold is immersed in the primary water tank unit 131, the secondary water tank unit 132, and the tertiary water tank unit 133 for three independent cleanings and the primary water tank unit 131 is provided with a quantitative pure water replenishment pipeline, the water in the primary water tank unit 131 will accumulate and overflow step by step to the secondary water tank unit 132 and the tertiary water tank unit 133 to form a step-by-step overflow structure, which is very beneficial to the cleaning effect and ensures the stability of continuous production.

[0044] Furthermore, if Figure 4As shown, the primary water tank unit 131 includes an upper pump 210, an upper diverter plate 220, an upper water outlet baffle 230, a lower water outlet baffle 330, a lower diverter plate 320, and a lower pump 310, which are arranged in sequence from top to bottom. A cavity is arranged between the upper water outlet baffle 230 and the lower water outlet baffle 330, and the cavity is used to place a semiconductor device 20 or a double-sided electronic electroplating mold. The structures of the primary water tank unit 131, the secondary water tank unit 132, and the tertiary water tank unit 133 are exactly the same.

[0045] Furthermore, the upper water outlet baffle 230 is provided with a plurality of upper water outlets, and the lower water outlet baffle 330 is provided with a plurality of lower water outlets. The porous structures of the upper water outlet baffle 230 and the lower water outlet baffle 330 form a porous flow stabilizing plate, which is preferably evenly arranged in the length direction of the bottom plate of the trough to form three equal parts, so as to ensure uniform distribution of water flow, effectively clean the upper silicone mask 121 and the lower silicone mask 124 in direct contact with the semiconductor device in the double-sided electronic electroplating mold, so that the solution used for bottom plating remaining on the surface thereof is evenly cleaned; at the same time, the oxidative effect of oxygen in the ambient atmosphere on the semiconductor device is suppressed to the maximum extent, thereby effectively maintaining the stability of continuous production.

[0046] Preferably, both the upper silicone mask 121 and the lower silicone mask 124 have inlay grooves adapted to semiconductor devices.

[0047] A double-sided local electronic electroplating method of the present invention can perform local electroplating treatment only in the area where signals are transmitted, and can prevent various situations that occur on the surface of copper materials in non-plated areas caused by existing electroplating methods: 1) substitution reaction with metals in other electroplating solutions resulting in poor products, and 2) oxidation reaction with oxygen in the ambient atmosphere resulting in performance loss of electronic components.

[0048] like Figure 3 As shown, the semiconductor device 20 to be plated is made of copper alloy material, has a size of 106.5×74.2 mm, and a thickness of 0.15 mm; it includes a double-sided electronic plating area 22 and six heat sinks 21. The double-sided electronic plating area 22 includes nine terminal pins, and the portion to be plated is the middle part of the nine terminal pins. The area of ​​the double-sided electronic plating area 22 is {(2×15)+(0.15×15)}×2=64.5 mm 2 .

[0049] For the electroplated products obtained by the above-mentioned double-sided local electronic electroplating method, the coating thickness test can be carried out: the FISCHERSCOPE X-RAY XDV-SDD detector manufactured by Fischer is used for testing Figure 3The nickel / gold plating film thickness at the central black dot of the nine terminal pins of the semiconductor device is measured, and the maximum value (Max), minimum value (Min), average value (Ave.), Max-Min and film thickness error value of the platinum plating film thickness data are analyzed.

[0050] Appearance inspection of nickel / gold-plated semiconductor device products: Observe with a 40x optical microscope and an electron microscope at 300x magnification, and judge the results according to the following standards: Excellent: The nickel / gold plating is uniform, smooth, free of bubbles, white spots, dirt, scratches, missing plating, seepage and other defects; Good: The defect area is determined based on the uniformity, smoothness, bubbles, pits, scratches, plating leakage, and plating penetration of the nickel / gold coating. The defect area is less than 3% of the overall test area. Medium: Determine the defect area based on the uniformity, smoothness, bubbles, pits, scratches, leakage plating, and penetration plating of the nickel / gold coating. The defect area is 3% of the overall test area ≤ 5% of the overall test area. Bad: Defect area is determined based on uniformity, smoothness, bubbles, pits, scratches, plating leakage, and penetration of nickel / gold plating. If the defect area is ≥ 5% of the overall test area, it is considered unqualified.

[0051] Nickel / gold plating semiconductor device product coating bonding strength test: according to the national standard CB / T 5270- -200X "Method for adhesion strength test of coating (electrodeposition layer and chemical deposition layer) on metal substrate" and GB12305.5-90 "Metal plating layer gold alloy electroplating layer experimental method part 5 bonding strength test" test method. After the semiconductor plated part is bent 180° under the action of external force, it is observed with a 40x optical microscope and an electron microscope magnified 300x, and the results are judged according to the following standards: Qualified: Check the bent part, the coating is qualified if there is no bubbling, peeling or falling off; Unqualified: Check the bent part. If the coating is bubbling, peeling or falling off, it is unqualified.

[0052] Neutral salt spray test for nickel / gold plating of nickel / gold-plated semiconductor device products: According to the national standard GB / T2423.17-2008 "Basic environmental testing procedures for electric and electronic products Test Ka: Salt spray test method", GB / T2423.18-2000 "Environmental testing for electric and electronic products Part 2: Test Test Kb: Salt spray, alternating (sodium chloride solution)" Test time: 96 hours, test equipment: MRT-YWX-90 salt spray corrosion tester After the test, the corrosion area caused by tiny pinholes and slits was detected using the 3D profile measuring instrument VR-6000 manufactured by Keyence. The percentage of the corrosion area to the total area of ​​the plating area is called the corrosion rate. The lower the corrosion rate, the fewer tiny pinholes and slits, and the higher the corrosion resistance of the nickel / gold plated semiconductor device product. Conversely, the higher the corrosion rate, the more tiny pinholes and slits, and the lower the corrosion resistance of the nickel / gold plated layer.

[0053] Nickel / gold plating layer porosity test of nickel / gold plated semiconductor device products: implemented in accordance with the national standard GB12305.3-90 "Metal plating layer gold alloy electroplating layer test method part 3 porosity test".

[0054] Since the process solution is likely to remain on the surface of the semiconductor device 20 during the electronic electroplating process, the residual solution remaining on the surface of the semiconductor device is thoroughly and evenly cleaned through the above-mentioned multiple cleaning processes, achieving the excellent result of no white spots, no dirt, and no color difference on the surface of the semiconductor device. Furthermore, in order to optimize the cleaning effect, we explore the optimal setting parameters of the double-sided cleaning device through the following examples and comparative examples to achieve the best cleaning effect. In the following embodiments, the numerical calculation of the CFD simulation model can be used to perform in-depth analysis of the parameter range, which helps to determine the research range of each parameter.

[0055] like Figure 4 The schematic diagram of the primary water tank unit 131 in the double-sided cleaning device 13 is shown, and the semiconductor device 20 runs in the direction of the arrow shown in the figure, the upper water outlet direction faces the surface of the semiconductor device and forms an angle δ with the running direction of the process flow, and the lower water outlet direction faces the surface of the semiconductor device and forms an angle α with the running direction of the process flow, and the optional range can be preferably 30°≤δ or α≤90° according to the simulation quantification experimental results of deriving simulation data from the CFD simulation model.

[0056] Example 1 Set δ=α=30°, the baffle water inlet diameters d and Φ of the upper and lower cleaning water tanks are both set to 6mm; the vertical distances Z and Y from the upper and lower water outlet baffles to the semiconductor devices are both set to 20mm; the cleaning solution flow rate of the upper and lower pumps is set to 90L / min.

[0057] Example 2 Set δ=α=90°, and the other parameters are consistent with those in Example 1.

[0058] The specific parameters and conditions of Example 1 and Example 2 are shown in Table 2: Table 2

[0059] The double-sided local electronic plating method of the present invention was used to process the semiconductor device according to the parameters and conditions of Example 1 and Example 2, and after 40 times microscope observation, it was found that the copper surface had Figure 9a The "color difference" phenomenon shown in the figure occurs; the cleaning effect obtained under the condition of 30° outlet angle in Example 1 is far from meeting the requirements of product appearance price, and the 90° condition in Example 2, such as Figure 9b As shown, although the color difference is not very obvious, the color difference can still be distinguished by careful observation.

[0060] Therefore, it is necessary to further optimize the water outlet angle of the partition in order to achieve the cleaning of the semiconductor device and make its surface uniform, smooth, free of bubbles, white spots, dirt and scratches.

[0061] Further changing δ and α, while keeping other conditions unchanged, as Example 3-6, the details are shown in Table 3: Table 3

[0062] Among them, the burr surface of the product obtained in Example 3 has color difference, such as Fig.10a As shown; the burr surface of the product obtained in Example 4 has a slight color difference, such as Fig.10b As shown; the copper surface of the product obtained in Example 5 has no color difference, as Fig.10c As shown; the burr surface of the product obtained in Example 6 has a slight color difference, such as Fig.10d shown.

[0063] According to the results, Examples 3 and 6 each have 1 sample with burr surface color difference, and the qualified rate is 90%, while the qualified rates of Examples 4 and 5 are both 100%. Among them, Examples 4 and 6 each have 1 sample with slight color difference on the burr surface, and 10 samples of Examples 4 and 5 are all color-free and no other appearance defects are detected. Therefore, the most preferred water outlet angle is 70°, that is, the conditions of Example 5, and the cleaning conditions of Example 5 can be applied to electronic electroplating process treatment.

[0064] When the outlet angle is selected as 70°, we further explore the upper and lower outlet diameters d and Φ. The optional range can be preferably 4.0-5.5 mm according to the simulation quantitative experimental results of deriving simulation data from the CFD simulation model. Different Φs are set as examples 7-10 for comparison. The other conditions are the same as those in example 5. The specific parameters are shown in Table 4: Table 4

[0065] It can be seen from Table 4 that the upper water outlet diameter d is the same as that in Example 5 and does not need to be replaced. It is only necessary to replace the lower water outlet diameter Φ of the 6 heat sinks in the lower baffle plate with a value of 4.0-5.5 mm.

[0066] According to the observation results, there is one sample with burr surface color difference in each of Examples 7 and 10, and the qualified rate is 90%, while no color difference and other appearance defects were found in Examples 8 and 9, and the qualified rate is 100%. Therefore, the most preferred conditions for the lower water outlet diameter Φ of the 6 heat sinks in the lower water outlet baffle are 4.5 and 5.0 mm, that is, Example 8 is the most excellent semiconductor device double-sided cleaning condition.

[0067] Further, when the water outlet angle is selected to be 70° and the lower water outlet diameter Φ is set to 4.5 and 5.0 mm, the simulation quantification experimental results of the simulation data derived from the construction of the CFD simulation model can be concluded that the preferred range of the vertical distance Z from the lower water outlet baffle to the semiconductor device is 25~45 mm. Different Zs are set for comparison as Examples 11-15, and the other conditions are the same as Example 8. The specific parameters are shown in Table 5.

[0068] Table 5

[0069] After observation, Examples 11 and 15 each had one sample with burr surface color difference, and the qualified rate was 90%, while Examples 12 to 14 had no color difference or other appearance defects, and the qualified rate was 100%. Therefore, the most preferred condition for the vertical distance Z from the lower water outlet baffle to the semiconductor device is 30 to 40 mm, that is, Example 13 is the most excellent semiconductor device double-sided cleaning condition.

[0070] Further, when the water outlet angle is selected to be 70°, the lower water outlet diameter Φ is set to 4.5 and 5.0 mm, and the vertical distance Z from the lower water outlet baffle to the semiconductor device is selected to be 30-40 mm, it can be concluded from the simulation quantization experimental results of the simulation data derived from the construction of the CFD simulation model that the preferred range of the frequency of the lower pump 310 is 25-45 Hz, and different Zs are set as Examples 16-20 for comparison, and the other conditions are the same as Example 13. The specific parameters are shown in Table 6: Table 6

[0071] After observation, Examples 16 and 20 each had one sample with burr surface color difference, and the qualified rate was 90%, while Examples 17 to 19 had no color difference or other appearance defects, and the qualified rate was 100%. Therefore, the most preferred condition for the frequency of the lower pump 310 is 30 to 40 Hz, that is, Examples 17 to 19 are the best preferred cleaning conditions, and the most suitable and optimal condition for double-sided cleaning of semiconductor devices is 35 Hz in Example 18.

[0072] In summary, through Examples 1-20, we can conclude that the optimal parameters of the primary water tank unit in the double-sided cleaning device are shown in Table 7, corresponding to Example 18.

[0073] Table 7

[0074] Comparative Examples 1 to 5 (Experiments for comparing and verifying the electronic electroplating production process flow of the prior art with the present invention) The electronic electroplating production process of the prior art only includes the following Figure 1 The steps of pre-treatment, washing and electronic plating shown in the embodiment of the present invention are missing. Figure 1 The two steps shown are double-sided local plating of the bottom metal film 110 and double-sided local plating of the precious metal 120. In addition, the prior art cleaning water tank is only equipped with one pump, and cannot independently control the upper and lower cleaning water supply. The outlet angle α is only designed to be fixed at 90°, which limits the possibility of obtaining the best cleaning conditions through the optimization of the outlet angle α. The specific parameters of the water tank are shown in Table 8.

[0075] Table 8

[0076] It can be seen from Table 8 that in the cleaning conditions of Comparative Example 1, the lower cleaning water outlet angle α is vertical 90°, the lower cleaning water outlet diameter Φ is the commonly used 6 mm, the cleaning time is 10 seconds, the same as in the embodiment, and the vertical distance Z between the semiconductor device and the lower cleaning water outlet is 35 mm, which has the best effect. Since there is only one pump, its frequency is 60 Hz.

[0077] Comparative Example 1 is the same as the embodiment. After cleaning 10 semiconductor devices, the results are obtained by the same detection method as in Example 1: there are 2 samples with color difference, 6 samples with white spots, and only 2 samples with qualified appearance. The details are shown in Table 9.

[0078] Table 9

[0079] It can be seen from Table 9 that the cleaning defect rate of semiconductor devices in Comparative Example 1 is as high as 80%, and the qualified rate of finished products is only 20%. Therefore, in order to improve the qualified rate of double-sided cleaning of semiconductor devices, the method of increasing the cleaning time is tried. The specific cleaning time is shown in Table 10.

[0080] Table 10

[0081] As shown in Table 10, the cleaning time of Comparative Examples 2 to 5 is increased by 1.5 to 3 times compared with Comparative Example 1. The cleaning method is the same as that of Comparative Example 1. After each cleaning process, 10 semiconductor devices are processed, and the same appearance inspection method is used. The results are shown in Table 11.

[0082] Table 11

[0083] It can be seen from Table 11 that the cleaning pass rates of Comparative Examples 1 to 5 are only 20% to 50%. Even if the cleaning time is increased by 3 times, the pass rate can only be increased to 50%. This proves that the cleaning tank structure and configuration of the prior art are imperfect when processing semiconductor double-sided local series products.

[0084] In summary, the cleaning process method of the prior art has defects in the cleaning effect because the cleaning tank device is not the best optimized solution. Therefore, there is a considerable gap between the low cleaning pass rate of 20%~50% in Examples 1~5 and the pass rate of 80%~100% in the preferred range of cleaning based on computational fluid dynamics of the present invention. This gap will lead to a serious decline in the quality of the final electroplated products of electronic electroplating, because color differences and white spots are generated not only on the copper surface of the non-plated area, but also on the surface of the local plated area. Therefore, if the copper surface has produced the white spots and color differences before electronic electroplating, it will lead to the inability to electroplate on the missing copper surface after electronic electroplating, thus resulting in copper leakage and loss. On the other hand, after the base layer of nickel is plated and thoroughly cleaned, it is set in the gold-plating mold, and the gold-plating solution remaining on the surface of the mold will not only contact the copper surface of the non-plated area, but also contact the nickel-plated surface of the plated area. Therefore, this uneven contact will not only lead to the loss of the copper surface of the non-plated area, but also the loss of the nickel-plated surface; the performance of the electronic electroplated products on both sides of the semiconductor device will be lost, resulting in unqualified products.

[0085] Therefore, compared with the excellent experimental results of the present invention, the electroplated products produced by the existing electroplating treatment process methods are missing a wide variety of types, resulting in unstable production, low product qualification rate, and seriously low product quality, which is incomparable to the excellent characteristics of the present invention. Therefore, the double-sided local electronic electroplating method based on computational fluid dynamics and its semiconductor electroplating products provided by the present invention can solve the white spots and color difference missing produced on the copper surface of electronic components in the existing electroplating process, and can prevent the problems of metal replacement on the copper surface and copper oxidation; and obtain a metal coating with excellent uniform distribution and density through double-sided local electronic electroplating equipment, which can meet the market demand for the production of semiconductor integrated circuit electronic products with high corrosion resistance, high-precision conductivity and high-quality electronic signal transmission performance.

[0086] In summary, the semiconductor device double-sided cleaning method based on computational fluid dynamics of the present invention also has the following beneficial effects: (1) The present invention can be applied to the precision manufacturing of semiconductor devices and electronic products. The surface of the semiconductor device material and the mask surface of the electronic electroplating mold formed have excellent cleanliness and uniformity, and are applicable to electronic electroplating production lines for high-end manufacturing of various semiconductor devices.

[0087] (2) Compared with the existing electroplating process, the double-sided cleaning process for semiconductor devices can achieve high-quality and high-efficiency cleaning process production of the entire surface of the semiconductor device. The product quality of the double-sided cleaning method of the semiconductor device of the present invention is excellent.

[0088] (3) The semiconductor device double-sided cleaning method of the present invention can quickly establish the optimal cleaning production conditions for various semiconductor devices with different structures through CFD space modeling.

[0089] Therefore, the semiconductor device double-sided cleaning method of the present invention has broad application prospects.

[0090] Although the present invention has been disclosed as above in the form of a preferred embodiment, it is not intended to limit the present invention. Anyone familiar with this technology can make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, the scope of protection of the present invention should be based on the definition of the claims.

Claims

1. A double-sided local electronic plating method, characterized in that: After the semiconductor device is pre-treated, the first plating part water washing, double-sided local base metal film plating, the second plating part water washing, the plating part acid washing, the third plating part water washing, double-sided local precious metal plating and the fourth plating part water washing are sequentially performed; wherein, the double-sided local base metal film plating and the double-sided local precious metal plating are both double-sided local electroplating treatments using double-sided electronic electroplating molds; The process of double-sided local plating of bottom metal film and double-sided local plating of precious metal respectively includes a primary mold circulation process for the double-sided electronic electroplating mold and a secondary mold circulation process for the double-sided electronic electroplating mold; the primary mold circulation process and the secondary mold circulation process are both configured to cyclically perform mold washing, mold drying, mold standby, semiconductor devices are arranged in the mold and then assembled in the electronic electroplating device, so as to clean the electroplating solution remaining in the mold so that the electroplating solution isolates the copper surface of the semiconductor device; The first plated parts water washing, the first mold circulation process, the second plated parts water washing, the plated parts pickling, the third plated parts water washing, the second mold circulation process and the fourth plated parts water washing are all cleaned by a double-sided cleaning device, and the double-sided cleaning device includes a first-level water tank unit, a second-level water tank unit, and a third-level water tank unit connected in sequence. When the first-level water tank unit is equipped with a quantitative pure water replenishment pipeline, the water in the first-level water tank unit will overflow step by step to the second-level water tank unit and the third-level water tank unit after accumulation, forming a step-by-step overflow structure.

2. A double-sided local electronic plating method according to claim 1, characterized in that: The primary water tank unit includes an upper pump, an upper diverter plate, an upper water outlet baffle, a lower water outlet baffle, a lower diverter plate, and a lower pump, which are arranged in sequence from top to bottom. A cavity is arranged between the upper water outlet baffle and the lower water outlet baffle, and the cavity is used to place semiconductor devices or double-sided electronic electroplating molds. The structures of the primary water tank unit, the secondary water tank unit, and the tertiary water tank unit are exactly the same.

3. A double-sided local electronic plating method according to claim 2, characterized in that: The distance between the semiconductor device / double-sided electronic electroplating mold and the upper water outlet baffle is set to 50 mm, and the distance between the semiconductor device / double-sided electronic electroplating mold and the lower water outlet baffle is set to 35 mm.

4. A double-sided local electronic plating method according to claim 3, characterized in that: The upper water outlet baffle is provided with a plurality of upper water outlets, and the lower water outlet baffle is provided with a plurality of lower water outlets. The water outlet angles of the upper water outlets and the water outlet angles of the lower water outlets are both set to 70 degrees.

5. A double-sided local electronic plating method according to claim 4, characterized in that: The diameter of the upper water outlet and the diameter of the lower water outlet are set to 6.0 mm and 4.5 mm respectively.

6. A double-sided local electronic plating method according to claim 5, characterized in that: The frequencies of the upper pump and the lower pump are set to 50 Hz and 40 Hz respectively, and the cleaning time is set to 15 seconds each time.

7. A double-sided local electronic plating method according to claim 1, characterized in that: The double-sided electronic electroplating mold includes an upper shell, an anode, an upper silicone mask, a lower silicone mask, an anode, and a lower shell which are arranged in sequence from top to bottom. A gap is left between the upper silicone mask and the lower silicone mask, and the gap is used to fix the semiconductor device.

8. A double-sided local electronic plating method according to claim 7, characterized in that: 10.0A / dm is used in the process of double-sided partial coating of bottom metal film and double-sided partial coating of precious metal. 2 The current density is set to 0.58A, the bath temperature is set to 50°C, and high-speed jet precision electronic electroplating equipment is used. A double-pulse power supply is used to energize the part to be plated of the semiconductor device for 23 seconds.

9. A double-sided local electronic plating method as claimed in claim 7, characterized in that: The upper silicone mask and the lower silicone mask both have inlay grooves adapted to semiconductor devices.

10. Application of a double-sided local electronic electroplating method as described in any one of claims 1 to 9 for local electroplating treatment in a signal transmission area.

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