Composite electrolytic anode device and electroplating method

Abstract

The invention relates to a composite electrolytic anode device and an electroplating method. The composite electrolytic anode device comprises a composite electrolytic anode assembly and a semiconductor lead frame which are arranged in an electroplating solution tank body, the composite electrolytic anode assembly comprises an anode plate and an anode spiral coil, and a plurality of through holes are formed in the anode plate; the semiconductor lead frame comprises a semiconductor lead frame front surface and a semiconductor lead frame back surface, and the two composite electrolytic anode assemblies are respectively a front surface composite electrolytic anode assembly and a back surface composite electrolytic anode assembly. According to the method, the accuracy of screening the film thickness of the metal coating in the plating area of the semiconductor lead frame can be quickly realized, the error of the film thickness of the coating of an actual electroplating product in the existing electroplating technology is greatly reduced, and the technical level of a composite electrolytic anode device can be further improved; the film thickness uniformity of the coating of the semiconductor lead frame is further improved, and the requirements of high-end semiconductor lead frame products for high-end performance and high quality are met.

Description

Technical Field

[0001] The invention relates to a composite electrolytic anode device and an electroplating method, belonging to the technical field of electroplating of semiconductor electronic products. Background Art

[0002] The electrolytic anode is an important component in the electrolytic metal plating process. It is the core electroplating technology for semiconductor lead frame electronic products that forms a nano-scale or micron-scale metal plating with a uniform distribution during the electrolysis process. The uniformity of the metal plating is the most important factor in characterizing electronic products. Only when the uniformity of the metal plating is met can the electroplating process be used to manufacture local electrolytic metal plating materials for precision and high-end semiconductor electronic components. At present, among the semiconductor lead frame electronic product technology equipment that is widely used in the aerospace field, flight control systems, navigation systems, communication systems and radar systems all require high-end products of semiconductor lead frames with high-precision and high-performance signal transmission. Among them, the electrolytic metal plating processing technology of lead frames for chip packaging in semiconductor electronic components is an extremely important link in the chip packaging production and manufacturing industry chain for high-performance semiconductor electronic products.

[0003] High-performance semiconductor lead frame high-end precision electrolytic metal plating products need to have reliable and excellent electronic information transmission performance, long-term stability and excellent corrosion resistance. Therefore, it is necessary to develop core electroplating technology with uniform nano-level or micron-level metal plating for various semiconductor lead frame electronic products.

[0004] However, the existing electroplating technology is used for the production and processing of various semiconductor lead frame electronic products. By using existing electrolytic anodes, it is difficult to obtain semiconductor lead frame electronic products with uniform metal coatings, resulting in unstable electronic information transmission performance, lack of long-term stability and excellent corrosion resistance.

[0005] Therefore, exploring an innovative composite electrolytic anode device and electroplating method to meet the needs of high-end semiconductor lead frames during the electroplating process, which requires electrolytic metal plating products to have uniform metal plating, reliable and excellent electronic information transmission performance, long-term stability and excellent corrosion resistance, has become a very important issue that needs to be solved urgently. Summary of the Invention

[0006] To solve the above problems, the present invention provides a composite electrolytic anode device and electroplating method to meet the needs of high-end semiconductor lead frames during the electroplating process, requiring electrolytic metal plating products to have uniform metal plating, reliable and excellent electronic information transmission performance, long-lasting stability and excellent corrosion resistance.

[0007] In order to achieve the above object, the technical solution adopted by the present invention is as follows: In a first aspect, the present invention provides a composite electrolysis anode device, comprising a composite electrolysis anode assembly disposed in an electroplating solution tank and a semiconductor lead frame; the composite electrolysis anode assembly comprises an anode plate and an anode spiral coil, the anode plate being provided with a plurality of through holes, the through holes of the anode plate being fixedly connected to the anode spiral coil via a locking ring to form the composite electrolysis anode assembly; the semiconductor lead frame comprising a front surface of the semiconductor lead frame and a back surface of the semiconductor lead frame, the composite electrolysis anode assembly comprising two components, namely a front composite electrolysis anode assembly and a back composite electrolysis anode assembly, the front composite electrolysis anode assembly being disposed on one side of the front surface of the semiconductor lead frame, and the back composite electrolysis anode assembly being disposed on one side of the back surface of the semiconductor lead frame; Wherein, the area of ​​the front composite electrolysis anode assembly is S 阳极a is the area of ​​the anode plate in the front composite electrolysis anode assembly N 正面 The area of ​​the anode spiral in the positive composite electrolysis anode assembly M 正面 The area of ​​the reverse composite electrolysis anode assembly S 阳极b is the area of ​​the anode plate in the reverse composite electrolysis anode assembly N 反面 The area of ​​the anode spiral in the reverse composite electrolysis anode assembly M 反面 The sum is: S 阳极a = N 正面 +M 正面 Formula 7 S 阳极b = N 反面 +M 反面 Formula 8 The area of ​​the front composite electrolysis anode assembly S 阳极a and the area of ​​the reverse composite electrolytic anode assembly S 阳极b , and the plated area of ​​the semiconductor lead frame front S 镀件a and the plating area on the reverse side of the semiconductor lead frame S 镀件b The ratio of meets the following range: 1.0< S 阳极a / S镀件a ≤5.0 Formula 9 1.0< S 阳极b / S 镀件b ≤5.0 Formula 10.

[0008] In one embodiment of the present invention, the relationship between the outer diameter of the bottommost spiral coil of the anode spiral coil and the range of the semiconductor lead frame plating area is: 20% C 正面 ≤ Z 正面 ≤35% C 正面 Formula 1 20% C 反面 ≤ Z 反面 ≤35% C 反面 Formula 2 in, Z 正面 is the outer diameter of the bottommost spiral coil of the anode spiral coil in the positive composite electrolysis anode assembly, Z 反面 is the outer diameter of the bottom spiral of the anode spiral in the reverse composite electrolysis anode assembly, C 正面 is the width of the front plating area of ​​the semiconductor lead frame, C 反面 It is the width of the back plating area of ​​the semiconductor lead frame.

[0009] In one embodiment of the present invention, the area calculation formula of the anode plate is: N 正面 = P 正面 ·H 正面 Formula 3 N 反面 = P 反面 ·H 反面 Formula 4 in, N 正面 is the area of ​​the anode plate in the positive composite electrolysis anode assembly, P 正面 is the length of the anode plate in the positive composite electrolysis anode assembly, H 正面 is the width of the anode plate in the front composite electrolysis anode assembly;N 反面 is the area of ​​the anode plate in the reverse composite electrolysis anode assembly, P 反面 is the length of the anode plate in the reverse composite electrolysis anode assembly, H 反面 is the width of the anode plate in the reverse composite electrolysis anode assembly.

[0010] In one embodiment of the present invention, the area calculation formula of the anode spiral coil is: M 正面 = L 正面 ·r 2 正面 ·π Formula 5 M 反面 = L 反面 ·r 2 反面 ·π Formula 6 in, M 正面 is the area of ​​the anode spiral in the positive composite electrolysis anode assembly, L 正面 is the length of the anode spiral in the positive composite electrolysis anode assembly, r 正面 is the wire radius of the anode spiral coil in the positive composite electrolysis anode assembly; M 反面 is the area of ​​the anode spiral in the reverse composite electrolysis anode assembly, L 反面 is the length of the anode spiral in the reverse composite electrolysis anode assembly, r 反面 It is the wire radius of the anode spiral coil in the reverse composite electrolysis anode assembly.

[0011] In one embodiment of the present invention, the metal material of the anode plate includes: titanium, titanium plated with platinum, and stainless steel.

[0012] In one embodiment of the present invention, the material of the lock ring is the same as that of the anode plate; the material of the anode spiral ring is the same as that of the anode plate.

[0013] In one embodiment of the present invention, the anode spiral coil has several layers of spiral coils, and the height difference between each layer of the anode spiral coil is 3 to 7 mm; and there is a gap of 2 to 5 mm between each layer of the anode spiral coil.

[0014] In one embodiment of the present invention, the electroplating solution tank is provided with an electroplating solution, and the metal types of the electroplating solution include: Single layer plating Au, Ag, Ni, Sn, Cu, Pd, Rh, Pt; Alloy plating: binary alloy metals of Au-Ni, Pd-Ni, Ni-P, and W-Ni.

[0015] In one embodiment of the present invention, a control system is also included, which includes: a plating solution heater, a pump for conveying the plating solution, and an electrolysis power supply; the control system is used to control the operation of the plating solution heater, the pump for conveying the plating solution, and the electrolysis power supply; and the actual electroplating operation is performed on both sides of the semiconductor lead frame plating area through the front composite electrolysis anode assembly and the back composite electrolysis anode assembly in the composite electrolysis anode device.

[0016] In a second aspect, the present invention provides an electroplating method using the composite electrolytic anode device, the electroplating method comprising the following steps: Step 1: providing the composite electrolysis anode device; Step 2: Determine the relationship between the outer diameter of the bottom spiral of the anode spiral and the range of the semiconductor lead frame plating area: 20% C 正面 ≤ Z 正面 ≤35% C 正面 Formula 1 20% C 反面 ≤ Z 反面 ≤35% C 反面 Formula 2 in, Z 正面 is the outer diameter of the bottommost spiral coil of the anode spiral coil in the positive composite electrolysis anode assembly, Z 反面 is the outer diameter of the bottom spiral of the anode spiral in the reverse composite electrolysis anode assembly, C 正面 is the width of the front plating area of ​​the semiconductor lead frame, C 反面 is the width of the back plating area of ​​the semiconductor lead frame; Step 3: Design anode plates of different areas. The area calculation formula is: N 正面 = P正面 ·H 正面 Formula 3 N 反面 = P 反面 ·H 反面 Formula 4 in, N 正面 is the area of ​​the anode plate in the positive composite electrolysis anode assembly, P 正面 is the length of the anode plate in the positive composite electrolysis anode assembly, H 正面 is the width of the anode plate in the front composite electrolysis anode assembly; N 反面 is the area of ​​the anode plate in the reverse composite electrolysis anode assembly, P 反面 is the length of the anode plate in the reverse composite electrolysis anode assembly, H 反面 is the width of the anode plate in the reverse composite electrolysis anode assembly; Step 4: Design anode spirals of different areas. The area calculation formula is: M 正面 = L 正面 ·r 2 正面 ·π Formula 5 M 反面 = L 反面 ·r 2 反面 ·π Formula 6 in, M 正面 is the area of ​​the anode spiral in the positive composite electrolysis anode assembly, L 正面 is the length of the anode spiral in the positive composite electrolysis anode assembly, r 正面 is the wire radius of the anode spiral coil in the positive composite electrolysis anode assembly; M 反面 is the area of ​​the anode spiral in the reverse composite electrolysis anode assembly, L 反面 is the length of the anode spiral in the reverse composite electrolysis anode assembly, r 反面is the wire radius of the anode spiral coil in the reverse composite electrolysis anode assembly; Step 5: Determine the area of ​​the positive composite electrolysis anode assembly S 阳极a is the area of ​​the anode plate in the front composite electrolysis anode assembly N 正面 The area of ​​the anode spiral in the positive composite electrolysis anode assembly M 正面 The sum of the reverse composite electrolysis anode assembly area S 阳极b is the area of ​​the anode plate in the reverse composite electrolysis anode assembly N 反面 The area of ​​the anode spiral in the reverse composite electrolysis anode assembly M 反面 The sum is: S 阳极a = N 正面 +M 正面 Formula 7 S 阳极b = N 反面 +M 反面 Formula 8 Step 6: Determine the area of ​​the positive composite electrolysis anode assembly S 阳极a and the area of ​​the reverse composite electrolytic anode assembly S 阳极b , and the plating area on the front side of the semiconductor lead frame S 镀件a and the plating area on the reverse side of the semiconductor lead frame S 镀件b The ratio of meets the following range: 1.0< S 阳极a / S 镀件a ≤5.0 Formula 9 1.0< S 阳极b / S 镀件b ≤5.0 formula 10 Step 7: According to formulas 9 and 10 in step 6, S 阳极a / S 镀件a and S 阳极b / S 镀件bCondition range, screening the measured metal coating of the plated area on the front of the plated part D 正实测 , the measured metal coating in the plating area on the reverse side of the plated part D 反实测 The standard for the metal coating on the front plating area of ​​the semiconductor lead frame is D 正标准 The standard for the metal coating on the reverse side of the semiconductor lead frame is D 反标准 ,Compare D 正实测 and D 正标准 、 D 反实测 and D 反标准 , if: D 正标准 < D 正实测 ≤ D 正标准 + 5% D 正标准 Formula 11 D 反标准 < D 反实测 ≤ D 反标准 + 5% D 反标准 Formula 12 Then confirm that the composite electrolysis anode device is applicable; otherwise, the actual D 正实测 and D 反实测 As a benchmark, correct S 阳极a and S 阳极b and verify D 正实测 and D 反实测 , until the discriminant formula 11 and the discriminant formula 12 are satisfied; Formula 11 and Formula 12 can be summarized as follows: the minimum error of the positive measured value based on the standard data of the metal coating is 100% ×〔( D Min正实测 - D 正标准 )÷ D 正标准 〕and the maximum error 100%×〔( D Max正实测 - D 正标准 )÷ D正标准 〕; The minimum error of the measured value on the reverse side is 100%×〔( D Min反实测 - D 反标准 )÷ D 反标准 〕and the maximum error 100%×〔( D Max反实测 - D 反标准 )÷ D 反标准 〕, which can be expressed as the following formula 13 and formula 14: 0%<〔( D 正实测 - D 正标准 )÷ D 正标准 〕×100%≤5%Formula 13 0%<〔( D 反实测 - D 反标准 )÷ D 反标准 〕×100%≤5%Formula 14 Formula 13 and Formula 14 are used as threshold references. If they are met, the selected anode spiral coil is applicable. Otherwise, its diameter and length are corrected until the selection meets the applicable range of Formula 13 and Formula 14.

[0017] The beneficial effects of the present invention are: The present invention provides a composite electrolytic anode device and electroplating method. The anode plate can be universally used without changing. Only anode spirals of different diameters and lengths need to be designed and replaced in combination to select the characteristics of the electroplating method suitable for the plating area of ​​semiconductor lead frames. The present invention optimizes the composite electrolytic anode device that can be combined and replaced and screens the results through actual testing of the control system to obtain the metal film thickness of the front plating area of ​​the semiconductor lead frame. D 正实测 Data is satisfying D 正标准 Under the premise of standard data, the metal film thickness is 100% ×〔( D Min正实测 - D 正标准 )÷ D 正标准 〕to 100%×〔( D Max正实测 - D 正标准 )÷ D 正标准The smaller the range, the smaller the error of the front plating area of ​​the semiconductor lead frame, which proves that the metal coating thickness distribution uniformity of the front plating area is better; by the same token, the obtained metal film thickness of the back plating area of ​​the semiconductor lead frame is D 反实测 Data is satisfying D 反标准 Under the premise of standard data, the metal film thickness is 100% ×〔( D Min反实测 - D 反标准 )÷ D 反标准 〕to 100%×〔( D Max反实测 - D 反标准 )÷ D 反标准 〕The smaller the range, the smaller the error of the back-plated area of ​​the semiconductor lead frame, which proves that the uniformity of the metal coating thickness distribution in the back-plated area is better; on the contrary, the design size of the anode spiral coil that cannot meet the discrimination formula 11 and discrimination formula 12, as well as discrimination formula 13 and discrimination formula 14 through the implementation of the test will be abandoned, and its diameter and length will be corrected until the variation range of the diameter and length of the screened anode spiral coil accurately meets the management requirements of the actual measured film thickness error threshold formulas 11 and 12, as well as formulas 13 and 14 of the semiconductor lead frame plating area obtained by actual measurement using a combinable and replaceable composite electrolytic anode device.

[0018] Based on the optimization results of the combinable and replaceable composite electrolytic anode device of the present invention, in the actual production process, the design and manufacturing method conditions of the diameter and length of the anode spiral coil in the composite electrolytic anode device of various semiconductor lead frames can be quickly established. Then, by obtaining the optimal electroplating control method of the composite electrolytic anode of the semiconductor lead frame, not only can the accuracy of the metal plating film thickness of the semiconductor lead frame plating area be quickly screened, and the error of the actual electroplating film thickness of the electroplated product with the existing electroplating technology be greatly reduced, but also the technical level of the composite electrolytic anode device can be further improved, and the uniformity of the semiconductor lead frame plating film thickness can be further improved, so as to meet the high-end performance and high quality requirements of high-end semiconductor lead frame products.

[0019] Based on the optimization results of the combinable and replaceable composite electrolytic anode device of the present invention, a considerable amount of electroplating metal raw materials can be saved in the actual production process, thereby reducing production costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0021] Figure 1 It is a planar schematic diagram of the anode plate provided by the present invention.

[0022] Figure 2 It is a three-dimensional schematic diagram of the anode spiral coil provided by the present invention.

[0023] Figure 3 It is a top view of the anode spiral coil provided by the present invention.

[0024] Figure 4 It is a planar schematic diagram of fixing the anode spiral coil to the anode plate using a locking ring provided by the present invention.

[0025] Figure 5 It is a three-dimensional schematic diagram of the front composite electrolysis anode assembly provided by the present invention.

[0026] Figure 6 It is a three-dimensional schematic diagram of the reverse composite electrolysis anode assembly provided by the present invention.

[0027] Figure 7 It is a schematic diagram of the plating area of ​​the semiconductor lead frame provided by the present invention.

[0028] Figure 8 It is a schematic diagram of the composite electrolysis anode device provided by the present invention.

[0029] Figure 9 This is a Max-Min variation trend diagram of the silver plating thickness difference of semiconductor lead frame electronic products provided by the present invention.

[0030] In the figure: 10, semiconductor lead frame; 10a, front side of semiconductor lead frame; 10b, back side of semiconductor lead frame; 100, anode plate; 200, anode spiral; 300, composite electrolytic anode assembly; 300a, front side composite electrolytic anode assembly; 300b, back side composite electrolytic anode assembly; 400, electroplating solution tank; 500, control system; 600, composite electrolytic anode device. DETAILED DESCRIPTION

[0031] The technical solution of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the embodiments described are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts are within the scope of protection of the present invention.

[0032] Example 1 like Figures 1 to 8 As shown, this embodiment provides a composite electrolytic anode device 600 for obtaining a precision semiconductor lead frame electronic product with a highly uniform electrolytic metal plating layer; the composite electrolytic anode device 600 includes a composite electrolytic anode assembly 300 and a semiconductor lead frame 10 disposed in an electroplating solution tank 400; the composite electrolytic anode assembly 300 includes an anode plate 100 and an anode spiral 200, the anode plate 100 is provided with a plurality of through holes, and the through holes of the anode plate 100 are fixedly connected to the anode spiral 200 by a locking ring. A composite electrolysis anode assembly 300 is formed; the semiconductor lead frame 10 includes a semiconductor lead frame front side 10a and a semiconductor lead frame back side 10b, and there are two composite electrolysis anode assemblies 300, namely a front composite electrolysis anode assembly 300a and a back composite electrolysis anode assembly 300b, the front composite electrolysis anode assembly 300a is arranged on one side of the semiconductor lead frame front side 10a, and the back composite electrolysis anode assembly 300b is arranged on one side of the semiconductor lead frame back side 10b.

[0033] Among them, the anode plate 100 can be universal, and the anode spiral coil 200 is designed according to the different electroplating areas and film thickness requirements of the semiconductor lead frame 10. The total area of ​​the designed composite electrolysis anode device 600 is different. Therefore, the design adjustment of the required different anode total areas only requires designing anode spiral coils 200 of different areas and combining and replacing them. In this embodiment, Figure 1 As shown, the anode plate 100 is provided with three through holes.

[0034] Alternatively, as Figure 2 As shown, the anode spiral coil 200 has several layers of spiral coils, and the height difference between each layer of spiral coils of the anode spiral coil 200 is 3 to 7 mm; Figure 3 As shown, there is a gap of 2 to 5 mm between each layer of the anode spiral coil 200 .

[0035] Optionally, the metal material of the anode plate 100 includes: titanium, titanium plated with platinum, and stainless steel. The selection needs to be determined according to the characteristics of the electroplating solution. According to the process technology requirements of the electroplating solution, some electrolytic anode metal surfaces need to be plated with precious metals; the material of the fixing lock ring is the same as the material of the anode plate 100; the material of the anode spiral ring 200 is the same as the material of the anode plate 100.

[0036] like Figure 4 As shown, the relationship between the outer diameter of the bottom spiral coil of the anode spiral coil 200 and the range of the plating area of ​​the semiconductor lead frame 10 is: 20% C 正面 ≤ Z 正面 ≤35% C 正面 Formula 1 20% C 反面 ≤ Z 反面 ≤35% C 反面 Formula 2 in, Z 正面 is the outer diameter of the bottommost spiral coil of the anode spiral coil 200 in the positive composite electrolysis anode assembly 300a, Z 反面 is the outer diameter of the bottommost spiral coil of the anode spiral coil 200 in the reverse composite electrolysis anode assembly 300b, C 正面 is the width of the plating area on the front side 10a of the semiconductor lead frame, C 反面 is the width of the plating area on the reverse side 10b of the semiconductor lead frame.

[0037] The anode plates 100 of different areas are designed, and the area calculation formula is: N 正面 = P 正面 ·H 正面 Formula 3 N 反面 = P 反面 ·H 反面 Formula 4 in, N 正面 is the area of ​​the anode plate 100 in the front composite electrolysis anode assembly 300a, P 正面is the length of the anode plate 100 in the front composite electrolysis anode assembly 300a, H 正面 is the width of the anode plate 100 in the front composite electrolysis anode assembly 300a; N 反面 is the area of ​​the anode plate 100 in the reverse composite electrolysis anode assembly 300b, P 反面 is the length of the anode plate 100 in the reverse composite electrolysis anode assembly 300b, H 反面 is the width of the anode plate 100 in the reverse composite electrolysis anode assembly 300b.

[0038] The anode spiral coils 200 of different areas are designed, and the area calculation formula is: M 正面 = L 正面 ·r 2 正面 ·π Formula 5 M 反面 = L 反面 ·r 2 反面 ·π Formula 6 in, M 正面 is the area of ​​the anode spiral 200 in the front composite electrolysis anode assembly 300a, L 正面 is the length of the anode spiral 200 in the positive composite electrolysis anode assembly 300a, r 正面 is the wire radius of the anode spiral coil 200 in the front composite electrolysis anode assembly 300a; M 反面 is the area of ​​the anode spiral 200 in the reverse composite electrolysis anode assembly 300b, L 反面 is the length of the anode spiral 200 in the reverse composite electrolysis anode assembly 300b, r 反面 is the wire radius of the anode spiral coil 200 in the reverse composite electrolysis anode assembly 300b.

[0039] The area of ​​the front composite electrolysis anode assembly 300a S 阳极a is the area of ​​the anode plate 100 in the front composite electrolysis anode assembly 300a N正面 The area of ​​the anode spiral 200 in the front composite electrolysis anode assembly 300a is M 正面 The area of ​​the reverse composite electrolysis anode assembly 300b S 阳极b is the area of ​​the anode plate 100 in the reverse composite electrolysis anode assembly 300b N 反面 The area of ​​the anode spiral 200 in the reverse composite electrolysis anode assembly 300b is M 反面 The sum of, as shown in Formula 7 and Formula 8: S 阳极a = N 正面 +M 正面 Formula 7 S 阳极b = N 反面 +M 反面 Formula 8 The area of ​​the front composite electrolysis anode assembly 300a S 阳极a and the area of ​​the reverse composite electrolytic anode assembly 300b S 阳极b , and the plating area of ​​the semiconductor lead frame front surface 10a S 镀件a and the plating area of ​​the semiconductor lead frame reverse side 10b S 镀件b The ratio needs to meet the following range, expressed by formulas 9 and 10: 1.0< S 阳极a / S 镀件a ≤5.0 Formula 9 1.0< S 阳极b / S 镀件b ≤5.0 formula 10 The front composite electrolytic anode assembly 300a and the back composite electrolytic anode assembly 300b obtain corresponding areas by adjusting the diameter and total length of the anode spiral coil 200 as the area and coating thickness of the front surface 10a and the back surface 10b of the semiconductor lead frame change, thereby increasing the coating thickness in the middle part of the semiconductor lead frame 10 to be close to the coating film thickness of the remaining parts of the semiconductor lead frame 10, thereby realizing a semiconductor lead frame electronic product with uniform metal coating distribution.

[0040] According to the above formulas 9 and 10 S 阳极a / S 镀件a and S 阳极b / S 镀件b Condition range, screening the measured metal coating of the plated area on the front of the plated part D 正实测 , the measured metal coating in the plating area on the reverse side of the plated part D 反实测 The standard of the metal coating of the semiconductor lead frame front 10a plating area is recorded as D 正标准 The standard of the metal coating of the semiconductor lead frame reverse side 10b plating area is recorded as D 反标准 ,Compare D 正实测 and D 正标准 、 D 反实测 and D 反标准 , if: D 正标准 < D 正实测 ≤ D 正标准 + 5% D 正标准 Formula 11 D 反标准 < D 反实测 ≤ D 反标准 + 5% D 反标准 Formula 12 Then confirm that the composite electrolysis anode device 600 is applicable; otherwise, the actual D 正实测 and D 反实测 As a benchmark, correct S 阳极a and S 阳极b and verify D 正实测 and D 反实测 , until the discriminant formula 11 and the discriminant formula 12 are satisfied.

[0041] Furthermore, formula 11 and formula 12 are summarized as follows: the minimum error of the positive measured value based on the standard data of the metal coating is 100% ×〔(D Min正实测 - D 正标准 )÷ D 正标准 〕and the maximum error 100%×〔( D Max正实测 - D 正标准 )÷ D 正标准 〕; Similarly, the minimum error of the measured value on the reverse side is 100%×〔( D Min反实测 - D 反标准 )÷ D 反标准 〕and the maximum error 100%×〔( D Max反实测 - D 反标准 )÷ D 反标准 〕, which can be expressed as the following formula 13 and formula 14: 0%<〔( D 正实测 - D 正标准 )÷ D 正标准 〕×100%≤5%Formula 13 0%<〔( D 反实测 - D 反标准 )÷ D 反标准 〕×100%≤5%Formula 14 Formula 13 and Formula 14 are used as threshold references. If they are satisfied, the selected anode spiral coil 200 is applicable. Otherwise, its diameter and length are corrected until the selection satisfies the applicable range of Formula 13 and Formula 14.

[0042] Furthermore, the metal types of the electroplating solution include: Single layer plating Au, Ag, Ni, Sn, Cu, Pd, Rh, Pt; Alloy plating: binary alloy metals of Au-Ni, Pd-Ni, Ni-P, and W-Ni.

[0043] Therefore, the replaceable composite electrolysis anode device 600 provided by the present invention, through the organic integration of the area calculation formulas 1 to 8 of the anode plate 100 and the anode spiral coil 200 and the management control system of the plating area ratio range formulas 9 and 10 of the semiconductor lead frame 10, establishes the judgment formulas 11 and 12 for the plating thickness of the semiconductor lead frame 10 plating area, and the judgment formulas 13 and 14 for the plating thickness error of the composite electrolysis anode device 600 provided by the present invention.

[0044] In addition, the composite electrolytic anode device 600 also includes a control system 500, which includes: a plating solution heater, a pump for conveying the plating solution, and an electrolytic power supply; the control system 500 is used to control the operation of the plating solution heater, the pump for conveying the plating solution, and the electrolytic power supply, and perform actual electroplating operations on both sides of the plating area of ​​the semiconductor lead frame 10 through the front composite electrolytic anode assembly 300a and the back composite electrolytic anode assembly 300b in the composite electrolytic anode device 600.

[0045] The control system 500 is based on the plating area of ​​the semiconductor lead frame 10 and is used to design a standard solution for the shape and area of ​​the anode plate 100 and the replaceable anode spiral 200 of the composite electrolysis anode device 600.

[0046] Furthermore, the control system 500 uses the plating area of ​​the semiconductor lead frame 10 as a reference to provide the electrolytic power supply with current conditions for calculating the electrolytic power supply, thereby facilitating the actual electroplating operation on the plating area of ​​the semiconductor lead frame 10 .

[0047] Example 2 This embodiment provides an electroplating method, using the composite electrolytic anode device provided in Example 1, including the following steps: Step 1: providing the composite electrolysis anode device 600; Step 2: Determine the relationship between the outer diameter of the bottom spiral coil of the anode spiral coil 200 and the range of the plating area of ​​the semiconductor lead frame 10 as follows: 20% C 正面 ≤ Z 正面 ≤35% C 正面 Formula 1 20% C 反面 ≤ Z 反面 ≤35% C 反面 Formula 2 in, Z 正面is the outer diameter of the bottommost spiral coil of the anode spiral coil 200 in the positive composite electrolysis anode assembly 300a, Z 反面 is the outer diameter of the bottommost spiral coil of the anode spiral coil 200 in the reverse composite electrolysis anode assembly 300b, C 正面 is the width of the plating area on the front side 10a of the semiconductor lead frame, C 反面 is the width of the plating area on the reverse side 10b of the semiconductor lead frame; Step 3: Design anode plates 100 of different areas. The area calculation formula is: N 正面 = P 正面 ·H 正面 Formula 3 N 反面 = P 反面 ·H 反面 Formula 4 in, N 正面 is the area of ​​the anode plate 100 in the front composite electrolysis anode assembly 300a, P 正面 is the length of the anode plate 100 in the front composite electrolysis anode assembly 300a, H 正面 is the width of the anode plate 100 in the front composite electrolysis anode assembly 300a; N 反面 is the area of ​​the anode plate 100 in the reverse composite electrolysis anode assembly 300b, P 反面 is the length of the anode plate 100 in the reverse composite electrolysis anode assembly 300b, H 反面 is the width of the anode plate 100 in the reverse composite electrolysis anode assembly 300b; Step 4: Design anode spiral coils 200 of different areas. The area calculation formula is: M 正面 = L 正面 ·r 2 正面 ·π Formula 5 M 反面 = L 反面·r 2 反面 ·π Formula 6 in, M 正面 is the area of ​​the anode spiral 200 in the front composite electrolysis anode assembly 300a, L 正面 is the length of the anode spiral 200 in the positive composite electrolysis anode assembly 300a, r 正面 is the wire radius of the anode spiral coil 200 in the front composite electrolysis anode assembly 300a; M 反面 is the area of ​​the anode spiral 200 in the reverse composite electrolysis anode assembly 300b, L 反面 is the length of the anode spiral 200 in the reverse composite electrolysis anode assembly 300b, r 反面 is the wire radius of the anode spiral coil 200 in the reverse composite electrolysis anode assembly 300b; Step 5: Determine the area of ​​the front composite electrolysis anode assembly 300a S 阳极a is the area of ​​the anode plate 100 in the front composite electrolysis anode assembly 300a N 正面 The area of ​​the anode spiral 200 in the front composite electrolysis anode assembly 300a is M 正面 The area of ​​the reverse composite electrolysis anode assembly 300b S 阳极b is the area of ​​the anode plate 100 in the reverse composite electrolysis anode assembly 300b N 反面 The area of ​​the anode spiral 200 in the reverse composite electrolysis anode assembly 300b is M 反面 The sum of, as shown in Formula 7 and Formula 8: S 阳极a = N 正面 +M 正面 Formula 7 S 阳极b = N 反面 +M 反面 Formula 8 Step 6: Determine the area of ​​the front composite electrolysis anode assembly 300a S 阳极aand the area of ​​the reverse composite electrolytic anode assembly 300b S 阳极b , and the plating area of ​​the semiconductor lead frame front surface 10a S 镀件a and the plating area of ​​the semiconductor lead frame reverse side 10b S 镀件b The ratio of meets the following range: 1.0< S 阳极a / S 镀件a ≤5.0 Formula 9 1.0< S 阳极b / S 镀件b ≤5.0 formula 10 The front composite electrolytic anode assembly 300a and the back composite electrolytic anode assembly 300b adjust the diameter and total length of the anode spiral coil 200 as the area and coating thickness of the front surface 10a and the back surface 10b of the semiconductor lead frame change, thereby obtaining a corresponding area, thereby increasing the coating thickness in the middle portion of the semiconductor lead frame 10 to be close to the coating thickness of the remaining portions of the semiconductor lead frame 10, thereby achieving a semiconductor lead frame electronic product with a uniform metal coating distribution. Step 7: According to formulas 9 and 10 in step 6, S 阳极a / S 镀件a and S 阳极b / S 镀件b Condition range, screening the measured metal coating of the plated area on the front of the plated part D 正实测 , the measured metal coating in the plating area on the reverse side of the plated part D 反实测 The standard of the metal coating of the semiconductor lead frame front 10a plating area is recorded as D 正标准 The standard of the metal coating of the semiconductor lead frame reverse side 10b plating area is recorded as D 反标准 ,Compare D 正实测 and D 正标准 、 D 反实测 and D 反标准 , if: D 正标准 < D 正实测≤ D 正标准 + 5% D 正标准 Formula 11 D 反标准 < D 反实测 ≤ D 反标准 + 5% D 反标准 Formula 12 Then confirm that the composite electrolysis anode device 600 is applicable; otherwise, the actual D 正实测 and D 反实测 As a benchmark, correct S 阳极a and S 阳极b and verify D 正实测 and D 反实测 , until the discriminant formula 11 and the discriminant formula 12 are satisfied; Formula 11 and Formula 12 can be summarized as follows: the minimum error of the positive measured value based on the standard data of the metal coating is 100% ×〔( D Min正实测 - D 正标准 )÷ D 正标准 〕and the maximum error 100%×〔( D Max正实测 - D 正标准 )÷ D 正标准 〕; Similarly, the minimum error of the measured value on the reverse side is 100%×〔( D Min反实测 - D 反标准 )÷ D 反标准 〕and the maximum error 100%×〔( D Max反实测 - D 反标准 )÷ D 反标准 〕, which can be expressed as the following formula 13 and formula 14: 0%<〔( D 正实测 - D 正标准 )÷ D 正标准 〕×100%≤5%Formula 13 0%<〔(D 反实测 - D 反标准 )÷ D 反标准 〕×100%≤5%Formula 14 Formula 13 and Formula 14 are used as threshold references. If they are satisfied, the selected anode spiral coil 200 is applicable. Otherwise, its diameter and length are corrected until the selection satisfies the applicable range of Formula 13 and Formula 14.

[0048] Example 3 This embodiment uses the composite electrolytic anode device provided in the first embodiment or the electroplating method provided in the second embodiment to perform an actual electroplating operation on the plating area of ​​the semiconductor lead frame 10, as shown in the following measurement 1, including: S1. Product specifications of semiconductor lead frame 10: The local plating area test piece to be processed in this embodiment is as follows: Figure 6 As shown, the dimensions are 93 mm wide by 139 mm long, with 5 columns and 5 rows, for a total of 25 units. The plating area dimensions of each unit on the front side 10a of the semiconductor lead frame are 16 x 19 mm; the silver plating film thickness standard is 1500 nm. Similarly, the plating area dimensions and silver plating film thickness standards of each unit on the back side 10b of the semiconductor lead frame are the same as those of the front side 10a of the semiconductor lead frame. S2. The plating area of ​​each unit on the front side 10a of the semiconductor lead frame is: 16×19mm=304mm 2 , then the plating area of ​​the front side 10a of the semiconductor lead frame is: S 镀件a =304×25=7600mm 2 Similarly, the plating area of ​​the reverse side 10b of the semiconductor lead frame is also: S 镀件b =304×25=7600mm 2 ; S3, the area of ​​the anode plate 100 in the front composite electrolysis anode assembly 300a, according to formula 9 and formula 10, select the area near the middle S 阳极a / S 镀件a The ratio is 2.5 and remains unchanged during the actual measurement. It should be noted that if the threshold value that meets the coating thickness judgment standard cannot be obtained under the ratio of 2.5 during the screening process, it is necessary to reselect S 阳极a / S 镀件a ratio.

[0049] 1.0< S 阳极a / S镀件a ≤5.0 Formula 9 1.0< S 阳极b / S 镀件b ≤5.0 formula 10 therefore, S 阳极a = S 镀件a ×2.5=7600×2.5=19000mm 2 According to the ratio conversion of the experimental piece size 93mm×139mm, the area of ​​the anode plate 100 in the positive composite electrolysis anode assembly 300a is 19000mm 2 The approximate dimensions of the anode plate 100 in the front composite electrolysis anode assembly 300a are converted by the same column: length 166 mm, width and thickness 115 mm. Similarly, the area and dimensions of the anode plate 100 in the rear composite electrolysis anode assembly 300b are the same as those of the anode plate 100 in the front composite electrolysis anode assembly 300a. S4. The area of ​​the anode spiral coil 200 in the front composite electrolysis anode assembly 300a. In the actual measurement 1 of the present invention, according to the requirements of the silver plating specifications of the semiconductor lead frame 10 product, the anode spiral coil 200 is made of stainless steel 316, the spiral coil wire diameter ranges from 0.5 to 3.5 mm, the length is 300 mm, and 5 layers are made; S5. The outer diameter of the bottom spiral of the anode spiral 200 in the front composite electrolysis anode assembly 300a is set to the width of the plating area on the front side 10a of the semiconductor lead frame. C 镀件正面 The relationship between is as shown in formula 1: 20% C 镀件正面 ≤ Z 正面 ≤35% C 镀件正面 Formula 1 Transform formula 1 into: 20%≤ Z 正面 / C 镀件正面 ≤35% formula 1 In S1, the product specification width of the semiconductor lead frame 10 is 93 mm. Therefore, when the outer diameter of the bottom spiral coil of the anode spiral coil 200 is selected as 30 mm, 30 / 93=32.3% meets the management range of formula 1. Therefore, the outer diameter of the anode spiral coil 200 produced by setting conditions 1 to 11 of measurement 1 is all 30 mm. Measurement 1 Various conditions of the anode spiral coil 200 for setting conditions 1 to 11 are shown in Table 1: Table 1 Anode spiral coil 200 in front composite electrolysis anode assembly 300a with different wire diameters of 300 mm in length

[0050] As shown in Table 1, when the diameter of the stainless steel 316 wire used to make the anode spiral coil 200 in the front composite electrolysis anode assembly 300a is changed from 0.5 to 4.5 mm under the setting conditions 1 to 11, the area of ​​the anode spiral coil 200 in the front composite electrolysis anode assembly 300a is M 正面 Calculated according to formula 5: M 正面 = L 正面 ·r 2 正面 ·π Formula 5 The results range from 58.9 to 4771.3 mm 2 Further, the area of ​​the positive composite electrolysis anode assembly 300a of the anode plate 100 N 正面 Calculated according to formula 3: N 正面 = P 正面 ·H 正面 Formula 3 The result is 19090.0mm 2 Therefore, the area of ​​the front composite electrolysis anode assembly 300a S 阳极a Calculated according to formula 7: S 阳极a = N 正面 +M 正面 Formula 7 The result range is 19148.9~23861.3mm 2 Furthermore, the ratio of the area of ​​the front composite electrolytic anode assembly 300a to the area of ​​the semiconductor lead frame front surface 10a ranges from 2.52 to 3.14, confirming that the management threshold range of Formula 9 is satisfied: 1.0< S 阳极a / S 镀件a ≤5.0 Formula 9 Similarly, since the plating conditions of the semiconductor lead frame rear surface 10b in the measurement 1 are the same as those of the semiconductor lead frame front surface 10a, the calculations based on Formulas 2, 4, 6, and 8 corresponding to the semiconductor lead frame rear surface 10b also yield the same results as those for the semiconductor lead frame front surface 10a. Therefore, when the diameter of the stainless steel 316 wire of the anode spiral coil 200 in the rear composite electrolysis anode assembly 300b varies from 0.5 mm to 4.5 mm, the area of ​​the rear composite electrolysis anode assembly 300b is S 阳极b The range is also 19148.9~23861.3mm 2 Furthermore, the ratio of the area of ​​the reverse composite electrolytic anode assembly 300b to the area of ​​the reverse side of the semiconductor lead frame 10b ranges from 2.52 to 3.14, which also confirms that the management threshold range of Formula 10 is satisfied: 1.0< S 阳极b / S 镀件b ≤5.0 formula 10 Furthermore, the comparative example in Table 1 is a conventional electroplating method using the electrolytic anode method of the prior art, that is, only the electrolytic anode plate 100 but no anode spiral ring 200. In the specific electroplating implementation, it will be compared and verified with the composite electrolytic anode method of the present invention.

[0051] S6, by Figure 2 It can be seen that the structure of the anode spiral coil 200 of the present invention has a height difference of 3 to 7 mm between each layer of the metal spiral coil, which is beneficial to the impact of the electroplating solution in the longitudinal space on the surface of the plating area of ​​the semiconductor lead frame 10 during the electroplating solution transportation process of the electrolytic device; at the same time, Figure 3 It can be seen that there is a gap of 2 to 5 mm between each layer of metal spiral turns; it is very beneficial to the smooth flow of the electroplating solution facing the surface of the plating area of ​​the semiconductor lead frame 10. In the process of the electroplating solution effectively flowing to the plating area, each time it flows through the surface of each layer of spiral turns, the anode surface electric line resonance enhancement effect will be obtained, which is beneficial to the improvement of the current efficiency of the reinforced area of ​​the anode spiral turn 200 of the present invention, thereby promoting the improvement of the efficiency of electrolytic metal deposition in the area, realizing the enhancement of the metal plating deposition function, and reducing the phenomenon of low metal plating between the plating areas outside the reinforced area.

[0052] S7, the composite electrolytic anode device composed of S1 to S6, and the auxiliary configuration form a control system 500, providing an electroplating method for the plating area of ​​the semiconductor lead frame 10; S8. Electroplating processing of the plating area of ​​the semiconductor lead frame 10 is managed according to the electroplating conditions of the plated parts, and the standard range of the metal coating of the plating area is improved by regulating the anode spiral ring 200; S9, the outer diameter of the bottom spiral of the anode spiral 200 is controlled by the width of the plating area on the front side 10a and the back side 10b of the semiconductor lead frame. C 镀件正面 and C 镀件反面 , controlling and managing the outer diameter of the bottom spiral Z 正面 and Z 反面 ; S10, electrolysis anode plate 100 condition control, through the set electrolysis anode plate 100 area N 正面 and N 反面 , the silver plating thickness obtained by actual measurement control management D 正面实测 and D 反面实测 ; S11, electrolysis anode spiral coil 200 condition control, by screening the diameter and length range of the anode spiral coil 200, that is, screening its area M 正面 and M 反面 , measured and controlled the silver coating thickness of the 200 area of ​​the anode spiral D 正实测 and D 反实测 ; S12, composite electrolysis anode assembly 300 condition control, by screening the area of ​​the front composite electrolysis anode assembly 300a S 阳极a and the area of ​​the reverse composite electrolytic anode assembly 300b S 阳极b , measuring and controlling the silver film thickness of 10 plating areas of semiconductor lead frame D 正实测 and D 反实测 ; S13, based on S7 to S12, the combinable replaceable composite electrolytic anode device and electroplating method are applied to the actual electroplating operation of the plating area of ​​the semiconductor lead frame 10 through the control system 500, using S3 S 阳极a / S 镀件a and S 阳极b / S 镀件b Condition range, screening the measured metal coating of the plated area on the front of the plated part D 正实测Indicates that the metal coating of the measured plating area on the reverse side is D 反实测 The standard of the metal coating of the semiconductor lead frame front surface 10a plating area is D 正标准 The standard of the metal coating of the semiconductor lead frame reverse side 10b plating area is recorded as D 反标准 ,Compare D 正实测 and D 正标准 、 D 反实测 and D 反标准 , if: D 正标准 < D 正实测 ≤ D 正标准 + 5% D 正标准 Formula 11 D 反标准 < D 反实测 ≤ D 反标准 + 5% D 反标准 Formula 12 Then confirm that the composite electrolysis anode device 600 is applicable; otherwise, the actual D 正实测 and D 反实测 As a benchmark, correct S 阳极a and S 阳极b and verify D 正实测 and D 反实测 , loop S8 to S13 until the discrimination formula 11 and the discrimination formula 12 are satisfied.

[0053] Furthermore, formula 11 and formula 12 are summarized as follows: the minimum error of the positive measured value based on the standard data of the metal coating is 100% ×〔( D Min正实测 - D 正标准 )÷ D 正标准 〕and the maximum error 100%×〔( D Max正实测 - D 正标准 )÷ D 正标准〕; Similarly, the minimum error of the positive measured value is 100%×〔( D Min反实测 - D 反标准 )÷ D 反标准 〕and the maximum error 100%×〔( D Max反实测 - D 反标准 )÷ D 反标准 〕, which can be expressed as the following formula 13 and formula 14; 0%<〔( D 正实测 - D 正标准 )÷ D 正标准 〕×100%≤5%Formula 13 0%<〔( D 反实测 - D 反标准 )÷ D 反标准 〕×100%≤5%Formula 14 Formula 13 and Formula 14 are used as threshold references. If they are satisfied, the selected anode spiral coil 200 is applicable. Otherwise, its diameter and length are corrected, and S8 to S13 are repeated until the applicable range of Formula 13 and Formula 14 is satisfied.

[0054] Furthermore, in the actual measurement 1 of the present invention, the electroplating solution is a silver plating solution.

[0055] test According to the above S3, conditions 2 and 10 are selected from the setting conditions 1 to 11 of the actual measurement 1 and the actual test is performed.

[0056] The test conditions implemented below are as follows: 1. Silver plating film thickness standard D 标准 ≥1500nm; 2. Uniformity of silver coating thickness distribution: 0.0%≤film thickness error<1.0%excellent 1.0%≤film thickness error<3.0%good 3.0%≤Film thickness error<5.0%Qualified 5.0%≤Film thickness error is unqualified 3. According to the test results of the uniformity of the silver coating thickness, determine the applicable range of the diameter and length of the anode spiral 200, that is, the area of ​​the anode spiral 200. M 正面 and M反面 Scope of application; 4. According to the test results of the uniformity of the silver film thickness distribution, determine the applicable range of the length and width of the anode plate 100, that is, the area of ​​the anode plate 100 N 正面 and N 反面 Scope of application; 5. Based on the silver film thickness distribution uniformity test results, determine the area of ​​the front composite electrolytic anode assembly 300a S 阳极a and the area of ​​the reverse composite electrolytic anode assembly 300b S 阳极b Scope of application; The film thickness is detected by Fischer FISCHERSCOPE X-RAY XDV-SDD. The detection position is the center position of the coating area of ​​the semiconductor lead frame 10 plating area. Figure 7 At each black dot (●); the test results of condition 2 are shown in Tables 2 and 3.

[0057] Table 2 Silver plating thickness under condition 2 D 正面 (nm)

[0058] As can be seen from Table 2, for the silver plating standard of 1500nm for the plating area of ​​the semiconductor lead frame 10, the measured range is 1509.13~1530.17nm, and the film thickness error range based on the silver plating standard of 1500nm is 0.61%~2.01%. According to the classification standard for the uniformity of the silver plating film thickness distribution, the film thickness error of 1.85%~2.63% is classified as good; on the other hand, the difference between the maximum and minimum values ​​of the film thickness Max-Min is 21.04nm, which has good distribution uniformity; therefore, condition 2 sets the area of ​​the front composite electrolytic anode assembly 300a formed by the electrolytic anode spiral coil 200 with a stainless steel 316 wire length of 300mm and a wire diameter of 0.9mm S 阳极a The silver plating thickness distribution uniformity of the plating area of ​​the front surface 10a of the semiconductor lead frame can be satisfied. Wherein, Max is the maximum film thickness, Min is the minimum film thickness, and Ave. is the average film thickness.

[0059] Table 3 Silver plating thickness under condition 2 D 反面 (nm)

[0060] As can be seen from Table 3, for the silver plating standard of 1500nm in the plating area of ​​the semiconductor lead frame 10, the measured range is 1509.27~1530.52nm, and the film thickness error range based on the silver plating standard of 1500nm is 0.62%~2.03%. According to the classification standard for the uniformity of the silver plating film thickness distribution, the film thickness error of 0.62%~2.03% is classified as good; on the other hand, the difference between the maximum and minimum values ​​of the film thickness Max-Min is 21.25nm, which has good distribution uniformity; therefore, condition 2 sets the area of ​​the reverse composite electrolytic anode assembly 300b formed by the electrolytic anode spiral coil 200 with a stainless steel 316 wire length of 300mm and a wire diameter of 0.9mm S 阳极b It can meet the classification requirements for uniformity of the silver plating film thickness distribution in the plating area on the reverse side 10b of the semiconductor lead frame.

[0061] Furthermore, the test results of condition 10 are shown in Tables 4 and 5.

[0062] Table 4 Silver plating thickness under condition 10 D 正面 (nm)

[0063] As can be seen from Table 4, for the silver plating standard of 1500nm in the plating area of ​​the semiconductor lead frame 10, the measured range is 1511.15~1578.81nm, and the film thickness error range based on the silver plating standard of 1500nm is 0.74%~5.25%. According to the classification standard for the uniformity of the distribution of the silver plating film thickness, the film thickness error of 0.74%~5.25% is classified as unqualified; on the other hand, the difference between the maximum and minimum values ​​of the film thickness Max-Min is 67.66nm, and the distribution uniformity of the film thickness has shown a large defect; therefore, condition 10 sets the area of ​​the positive composite electrolytic anode assembly 300a formed by the electrolytic anode spiral coil 200 with a stainless steel 316 wire length of 300mm and a wire diameter of 4.1mm S 阳极a This is insufficient to meet the classification requirements for uniformity of the silver plating film thickness distribution in the plating area of ​​the front side 10a of the semiconductor lead frame.

[0064] Table 5 Silver plating thickness under condition 10 D 反面 (nm)

[0065] As can be seen from Table 5, for the silver plating standard of 1500nm in the plating area of ​​the semiconductor lead frame 10, the measured range is 1511.63~1579.36nm, and the film thickness error range based on the silver plating standard of 1500nm is 0.78%~5.29%. According to the classification standard for the uniformity of the distribution of the silver plating film thickness, the film thickness error of 0.78%~5.29% is classified as unqualified; on the other hand, the difference between the maximum and minimum values ​​of the film thickness Max-Min is 67.73nm, and the distribution uniformity of the film thickness has shown a large defect; therefore, condition 10 sets the area of ​​the reverse composite electrolytic anode assembly 300b formed by the electrolytic anode spiral coil 200 with a stainless steel 316 wire length of 300mm and a wire diameter of 4.1mm S 阳极b The classification requirements for uniformity of the silver plating film thickness distribution in the plating area on the reverse side 10b of the semiconductor lead frame are not met.

[0066] In order to screen a more accurate scope of application, further actual tests are conducted on conditions 1 and 9.

[0067] The test results of condition 1 are shown in Tables 6 and 7.

[0068] Table 6 Silver plating thickness under condition 1 D 正面 (nm)

[0069] As can be seen from Table 6, for the silver plating standard of 1500nm in the plating area of ​​the semiconductor lead frame 10, the measured range is 1507.34~1532.94nm, and the film thickness error range based on the silver plating standard of 1500nm is 0.49%~2.20%. According to the classification standard for the uniformity of the distribution of the silver plating film thickness, the film thickness error of 0.49%~2.20% is classified as good; on the other hand, the difference between the maximum and minimum values ​​of the film thickness Max-Min is 25.60nm, which has good distribution uniformity; therefore, condition 1 sets the area of ​​the front composite electrolytic anode assembly 300a formed by the electrolytic anode spiral coil 200 with a stainless steel 316 wire length of 300mm and a wire diameter of 0.5mm S 阳极a The classification requirements for the uniformity of the silver plating film thickness distribution in the plating area of ​​the front surface 10a of the semiconductor lead frame can be met.

[0070] Table 7 Silver plating thickness under condition 1 D 反面 (nm)

[0071] As can be seen from Table 7, for the silver plating standard of 1500nm in the plating area of ​​the semiconductor lead frame 10, the measured range is 1508.69~1534.87nm, and the film thickness error range based on the silver plating standard of 1500nm is 0.58%~2.32%. According to the classification standard for the uniformity of the distribution of the silver plating film thickness, the film thickness error of 0.58%~2.32% is classified as good; on the other hand, the difference between the maximum and minimum values ​​of the film thickness Max-Min is 26.18nm, which has good distribution uniformity; therefore, condition 1 sets the area of ​​the reverse composite electrolytic anode assembly 300b formed by the electrolytic anode spiral coil 200 with a stainless steel 316 wire length of 300mm and a wire diameter of 0.5mm S 阳极b It can meet the classification requirements of uniformity of the silver plating film thickness distribution in the plating area on the reverse side 10b of the semiconductor lead frame.

[0072] The test results of condition 9 are shown in Tables 8 and 9.

[0073] Table 8 Silver plating thickness under condition 9 D 正面 (nm)

[0074] As can be seen from Table 8, for the silver plating standard of 1500nm in the plating area of ​​the semiconductor lead frame 10, the measured range is 1511.23~1565.23nm, and the film thickness error range based on the silver plating standard of 1500nm is 0.75%~4.35%. According to the classification standard for the uniformity of the distribution of the silver plating film thickness, the film thickness error of 0.75%~4.35% is classified as good; on the other hand, the difference between the maximum and minimum values ​​of the film thickness Max-Min is 54.00nm, which has relatively good distribution uniformity compared with condition 10; therefore, condition 9 sets the area of ​​the front composite electrolytic anode assembly 300a formed by the electrolytic anode spiral coil 200 with a stainless steel 316 wire length of 300mm and a wire diameter of 3.7mm S 阳极a The classification requirements for the uniformity of the silver plating film thickness distribution in the plating area of ​​the front surface 10a of the semiconductor lead frame can be met.

[0075] Table 9 Silver plating thickness under condition 9 D 反面 (nm)

[0076] As can be seen from Table 9, for the silver plating standard of 1500nm in the plating area of ​​the semiconductor lead frame 10, the measured range is 1512.36~1566.75nm, and the film thickness error range based on the silver plating standard of 1500nm is 0.82%~4.45%. According to the classification standard for the uniformity of the silver plating film thickness distribution, the film thickness error of 0.82%~4.45% is classified as good; on the other hand, the difference between the maximum and minimum values ​​of the film thickness Max-Min is 54.39nm, which has relatively good distribution uniformity compared with condition 10; therefore, condition 9 sets the area of ​​the reverse composite electrolytic anode assembly 300b formed by the electrolytic anode spiral coil 200 with a stainless steel 316 wire length of 300mm and a wire diameter of 3.7mm S 阳极b It can meet the classification requirements for uniformity of the silver plating film thickness distribution in the plating area on the reverse side 10b of the semiconductor lead frame.

[0077] The actual test conditions of conditions 3 to 8 are shown in Table 1, and the data processing method is the same as that of condition 2.

[0078] Comparative Example: Except for deactivating the anode spiral coil 200 of the present invention, other setting conditions and data processing methods are the same as those of condition 2: The results of conditions 1 to 10 of the actual test are shown in Tables 10 and 11; Table 10 Silver plating film thickness test results D 正面 (nm)

[0079] From conditions 3 to 8 in Table 10, it can be seen that for the silver plating standard of 1500nm in the plating area of ​​the semiconductor lead frame 10, the actual measured range is between conditions 2 and 9. Therefore, the area of ​​the front composite electrolytic anode assembly 300a formed by the electrolytic anode spiral coil 200 with a wire diameter of 1.3 to 3.3 mm is S 阳极a The classification requirements for the uniformity of the silver plating film thickness distribution in the plating area of ​​the front surface 10a of the semiconductor lead frame can be met.

[0080] Furthermore, it can be seen from the comparative example in Table 10 that for the silver plating standard of 1500nm for the plated parts, the actual measured range is 1510.72~1698.92nm, and the film thickness error range based on the silver plating standard of 1500nm is 0.71%~13.26%. According to the classification standard for the detection of uniformity of silver plating film thickness distribution, the film thickness error of 0.71%~13.26% is classified as unqualified; on the other hand, the difference between the maximum and minimum values ​​of the film thickness Max-Min is 188.2nm, which shows a huge gap; therefore, the film thickness data obtained by actual measurement of the commonly used electrolytic anode in the prior art does not meet the classification requirements for the uniformity of the silver plating film thickness distribution in the plating area 10a on the front side of the semiconductor lead frame.

[0081] Table 11 Silver plating film thickness test results D 反面 (nm)

[0082] From conditions 3 to 8 in Table 11, it can be seen that for the silver plating standard of 1500nm in the plating area of ​​the semiconductor lead frame 10, the actual measured range is between conditions 2 and 9. Therefore, the area of ​​the reverse composite electrolytic anode assembly 300b formed by the electrolytic anode spiral coil 200 with a wire diameter of 1.3 to 3.3 mm is S 阳极b It can meet the classification requirements for uniformity of the silver plating film thickness distribution in the plating area on the reverse side 10b of the semiconductor lead frame.

[0083] Furthermore, it can be seen from the comparative example in Table 11 that for the silver plating standard of 1500nm for the plated parts, the actual measured range is 1510.72~1698.92nm, and the film thickness error range based on the silver plating standard of 1500nm is 0.71%~13.26%. According to the classification standard for the detection of uniformity of silver plating film thickness distribution, the film thickness error of 0.71%~13.26% is classified as unqualified; on the other hand, the difference between the maximum and minimum values ​​of the film thickness Max-Min is 188.2nm, which shows a huge gap; therefore, the film thickness data obtained by actual measurement of the commonly used electrolytic anode in the prior art does not meet the classification requirements for the uniformity of the silver plating film thickness distribution in the plating area 10b on the back side of the semiconductor lead frame.

[0084] Furthermore, in order to more intuitively describe the distribution uniformity of the silver film thickness of the semiconductor lead frame 10 by the difference between the maximum and minimum film thickness values ​​Max-Min, the results are as follows: Figure 9 The Max-Min data curve is shown in the figure.

[0085] from Figure 9It can be seen that the Max-Min difference of the comparative example numbered 0 is very high, which proves that the existing electroplating technology only has the electroplating method of the electrolytic anode plate, and the resulting silver-plated film thickness data fluctuates greatly, that is, the distribution uniformity of the film thickness is very poor; and the Max-Min difference of conditions 1 to 10 of the present invention is significantly improved compared with the comparative example, that is, through the electroplating method of the composite electrolytic anode that can be combined and replaced, the Max-Min difference is greatly reduced from 188.2 to 196.15 nm in the prior art to 18.75 to 67.73 nm, and the distribution uniformity of the film thickness reaches a very excellent level.

[0086] It can be further seen that, through the combined effect of the electrolytic anode spiral coil 200 of the present invention, the distribution of the silver plating film thickness under condition 1 is that the film thickness of the outer periphery of the plating area of ​​the semiconductor lead frame 10 is relatively high, and the film thickness of the central area is relatively low. As the area of ​​the electrolytic anode spiral coil 200 increases, the outer periphery film thickness gradually decreases, and the film thickness of the central area gradually increases. When it reaches near condition 5, the difference between the outer periphery film thickness and the central area film thickness reaches the minimum; starting from condition 6, the film thickness of the central area of ​​the plating area of ​​the semiconductor lead frame 10 is higher than the outer periphery film thickness, and as the area of ​​the electrolytic anode spiral coil 200 increases, this trend gradually strengthens from conditions 6 to 10.

[0087] pass Figure 9 It can be seen that according to the discrimination formula 13 and formula 14, the test results of the screened conditions 1 to 8 can meet the discrimination conditions and can be used as applicable conditions in actual electroplating production; however, in order to better improve the yield of electroplated products in actual electroplating production management, more optimized conditions 1 to 6 can be selected for management; further, since there are many factors that affect the quality of electroplated products in electroplating production, selecting the optimal conditions 3 to 5 for management can obtain the optimized yield of electroplated products.

[0088] from Figure 9 It can be further seen that, compared with existing electroplating methods, the electroplating method of the composite electrolytic anode provided by the present invention can save a considerable amount of silver plating raw materials and reduce production costs in actual production activities.

[0089] Furthermore, the measured series 1 is a measured screening based on the conditions that the plating area 10a of the front side of the semiconductor lead frame and the plating area 10b of the back side of the semiconductor lead frame have the same area and the same coating film thickness; similarly, when the plating area 10a of the front side of the semiconductor lead frame and the plating area 10b of the back side of the semiconductor lead frame have different areas and the coating film thickness is different, the composite electrolytic anode device and electroplating method of the present invention can also be used to measure and screen the optimal electroplating production conditions.

[0090] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. These modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the various embodiments of the present invention, and should all be included in the scope of protection of the present invention.

Claims

1. A composite electrolysis anode device, characterized in that: The invention comprises a composite electrolytic anode assembly (300) and a semiconductor lead frame (10) arranged in an electroplating solution tank (400); the composite electrolytic anode assembly (300) comprises an anode plate (100) and an anode spiral ring (200); the anode plate (100) is provided with a plurality of through holes, and the through holes of the anode plate (100) are fixedly connected to the anode spiral ring (200) through a locking ring to form the composite electrolytic anode assembly (300); the semiconductor lead frame (10) comprises a semiconductor A lead frame front side (10a) and a semiconductor lead frame back side (10b), wherein the number of the composite electrolysis anode assemblies (300) is two, namely a front composite electrolysis anode assembly (300a) and a back composite electrolysis anode assembly (300b), wherein the front composite electrolysis anode assembly (300a) is arranged on one side of the semiconductor lead frame front side (10a), and the back composite electrolysis anode assembly (300b) is arranged on one side of the back side (10b) of the semiconductor lead frame; Wherein, the area of ​​the front composite electrolysis anode assembly (300a) is S 阳极a is the area of ​​the anode plate (100) in the front composite electrolysis anode assembly (300a) N 正面 The area of ​​the anode spiral coil (200) in the front composite electrolysis anode assembly (300a) M 正面 The area of ​​the reverse composite electrolysis anode assembly (300b) S 阳极b is the area of ​​the anode plate (100) in the reverse composite electrolysis anode assembly (300b) N 反面 The area of ​​the anode spiral (200) in the reverse composite electrolysis anode assembly (300b) M 反面 The sum is: S 阳极a = N 正面 +M 正面 Formula 7 S 阳极b = N 反面 +M 反面 Formula 8 The area of ​​the front composite electrolysis anode assembly (300a) S 阳极a and the area of ​​the reverse composite electrolytic anode assembly (300b) S 阳极b , and the plating area of ​​the front side (10a) of the semiconductor lead frame S 镀件a and the plating area on the reverse side (10b) of the semiconductor lead frame S 镀件b The ratio of meets the following range: 1.0< S 阳极a / S 镀件a ≤5.0 Formula 9 1.0< S 阳极b / S 镀件b ≤5.0 Formula 10.

2. A composite electrolysis anode device according to claim 1, characterized in that: The relationship between the outer diameter of the bottom spiral coil of the anode spiral coil (200) and the range of the plating area of ​​the semiconductor lead frame (10) is: 20% C 正面 ≤ Z 正面 ≤35% C 正面 Formula 1 20% C 反面 ≤ Z 反面 ≤35% C 反面 Formula 2 in, Z 正面 is the outer diameter of the bottommost spiral coil of the anode spiral coil (200) in the front composite electrolysis anode assembly (300a), Z 反面 is the outer diameter of the bottom spiral coil of the anode spiral coil (200) in the reverse composite electrolysis anode assembly (300b), C 正面 is the width of the plating area on the front side (10a) of the semiconductor lead frame, C 反面 is the width of the plating area on the reverse side (10b) of the semiconductor lead frame.

3. A composite electrolysis anode device according to claim 1, characterized in that: The area calculation formula of the anode plate (100) is: N 正面 = P 正面 ·H 正面 Formula 3 N 反面 = P 反面 ·H 反面 Formula 4 in, N 正面 is the area of ​​the anode plate (100) in the front composite electrolysis anode assembly (300a), P 正面 is the length of the anode plate (100) in the front composite electrolysis anode assembly (300a), H 正面 is the width of the anode plate (100) in the front composite electrolysis anode assembly (300a); N 反面 is the area of ​​the anode plate (100) in the reverse composite electrolysis anode assembly (300b), P 反面 is the length of the anode plate (100) in the reverse composite electrolysis anode assembly (300b), H 反面 is the width of the anode plate (100) in the reverse composite electrolysis anode assembly (300b).

4. A composite electrolysis anode device according to claim 1, characterized in that: The area calculation formula of the anode spiral coil (200) is: M 正面 = L 正面 ·r 2 正面 ·π Formula 5 M 反面 = L 反面 ·r 2 反面 ·π Formula 6 in, M 正面 is the area of ​​the anode spiral (200) in the front composite electrolysis anode assembly (300a), L 正面 is the length of the anode spiral coil (200) in the front composite electrolysis anode assembly (300a), r 正面 is the wire radius of the anode spiral coil (200) in the front composite electrolysis anode assembly (300a); M 反面 is the area of ​​the anode spiral (200) in the reverse composite electrolysis anode assembly (300b), L 反面 is the length of the anode spiral coil (200) in the reverse composite electrolysis anode assembly (300b), r 反面 is the wire radius of the anode spiral coil (200) in the reverse composite electrolysis anode assembly (300b).

5. A composite electrolysis anode device according to claim 1, characterized in that: The metal material of the anode plate (100) includes: titanium, titanium plated with platinum, and stainless steel.

6. A composite electrolysis anode device according to claim 5, characterized in that: The material of the lock ring is the same as that of the anode plate (100); and the material of the anode spiral ring (200) is the same as that of the anode plate (100).

7. A composite electrolysis anode device according to claim 1, characterized in that: The anode spiral coil (200) has several layers of spiral coils, and the height difference between the spiral coils of each layer of the anode spiral coil (200) is 3 to 7 mm; and there is a gap of 2 to 5 mm between the spiral coils of each layer of the anode spiral coil (200).

8. The composite electrolysis anode device according to claim 1, characterized in that: The electroplating solution tank (400) is provided with an electroplating solution, and the metal types of the electroplating solution include: Single layer plating Au, Ag, Ni, Sn, Cu, Pd, Rh, Pt; Alloy plating: binary alloy metals of Au-Ni, Pd-Ni, Ni-P, and W-Ni.

9. The composite electrolysis anode device according to claim 1, characterized in that: The invention also includes a control system (500), wherein the control system (500) includes: an electroplating solution heater, a pump for conveying the electroplating solution, and an electrolysis power supply; the control system (500) is used to control the operation of the electroplating solution heater, the pump for conveying the electroplating solution, and the electrolysis power supply; and the actual electroplating operation is performed on both sides of the plating area of ​​the semiconductor lead frame (10) through the front composite electrolysis anode assembly (300a) and the back composite electrolysis anode assembly (300b) in the composite electrolysis anode device (600).

10. An electroplating method, characterized in that: Using the composite electrolytic anode device according to any one of claims 1 to 9, the electroplating method comprises the following steps: Step 1: providing the composite electrolysis anode device (600); Step 2: Determine the relationship between the outer diameter of the bottom spiral coil of the anode spiral coil (200) and the range of the plating area of ​​the semiconductor lead frame (10): 20% C 正面 ≤ Z 正面 ≤35% C 正面 Formula 1 20% C 反面 ≤ Z 反面 ≤35% C 反面 Formula 2 in, Z 正面 is the outer diameter of the bottommost spiral coil of the anode spiral coil (200) in the front composite electrolysis anode assembly (300a), Z 反面 is the outer diameter of the bottom spiral coil of the anode spiral coil (200) in the reverse composite electrolysis anode assembly (300b), C 正面 is the width of the plating area on the front side (10a) of the semiconductor lead frame, C 反面 is the width of the plating area on the reverse side (10b) of the semiconductor lead frame; Step 3: Design anode plates (100) of different areas. The area calculation formula is: N 正面 = P 正面 ·H 正面 Formula 3 N 反面 = P 反面 ·H 反面 Formula 4 in, N 正面 is the area of ​​the anode plate (100) in the front composite electrolysis anode assembly (300a), P 正面 is the length of the anode plate (100) in the front composite electrolysis anode assembly (300a), H 正面 is the width of the anode plate (100) in the front composite electrolysis anode assembly (300a); N 反面 is the area of ​​the anode plate (100) in the reverse composite electrolysis anode assembly (300b), P 反面 is the length of the anode plate (100) in the reverse composite electrolysis anode assembly (300b), H 反面 is the width of the anode plate (100) in the reverse composite electrolysis anode assembly (300b); Step 4: Design anode spirals (200) of different areas. The area calculation formula is: M 正面 = L 正面 ·r 2 正面 ·π Formula 5 M 反面 = L 反面 ·r 2 反面 ·π Formula 6 in, M 正面 is the area of ​​the anode spiral (200) in the front composite electrolysis anode assembly (300a), L 正面 is the length of the anode spiral coil (200) in the front composite electrolysis anode assembly (300a), r 正面 is the wire radius of the anode spiral coil (200) in the front composite electrolysis anode assembly (300a); M 反面 is the area of ​​the anode spiral (200) in the reverse composite electrolysis anode assembly (300b), L 反面 is the length of the anode spiral coil (200) in the reverse composite electrolysis anode assembly (300b), r 反面 is the wire radius of the anode spiral coil (200) in the reverse composite electrolysis anode assembly (300b); Step 5: Determine the area of ​​the positive composite electrolysis anode assembly (300a) S 阳极a is the area of ​​the anode plate (100) in the front composite electrolysis anode assembly (300a) N 正面 The area of ​​the anode spiral coil (200) in the front composite electrolysis anode assembly (300a) M 正面 The sum of the reverse composite electrolysis anode assembly (300b) area S 阳极b is the area of ​​the anode plate (100) in the reverse composite electrolysis anode assembly (300b) N 反面 The area of ​​the anode spiral (200) in the reverse composite electrolysis anode assembly (300b) M 反面 The sum is: S 阳极a = N 正面 +M 正面 Formula 7 S 阳极b = N 反面 +M 反面 Formula 8 Step 6: Determine the area of ​​the positive composite electrolysis anode assembly (300a) S 阳极a and the area of ​​the reverse composite electrolytic anode assembly (300b) S 阳极b , and the plating area of ​​the semiconductor lead frame front side (10a) S 镀件a and the plating area on the reverse side (10b) of the semiconductor lead frame S 镀件b The ratio of meets the following range: 1.0< S 阳极a / S 镀件a ≤5.0 Formula 9 1.0< S 阳极b / S 镀件b ≤5.0 Formula 10 Step 7: According to formulas 9 and 10 in step 6, S 阳极a / S 镀件a and S 阳极b / S 镀件b Condition range, screening the measured metal coating of the plated area on the front of the plated part D 正实测 , the measured metal coating in the plating area on the reverse side of the plated part D 反实测 , the standard of the metal coating on the front side (10a) of the semiconductor lead frame is recorded as D 正标准 , the standard of the metal coating on the reverse side (10b) of the semiconductor lead frame is recorded as D 反标准 ,Compare D 正实测 and D 正标准 、 D 反实测 and D 反标准 , if: D 正标准 < D 正实测 ≤ D 正标准 + 5% D 正标准 Formula 11 D 反标准 < D 反实测 ≤ D 反标准 + 5% D 反标准 Formula 12 Then confirm that the composite electrolysis anode device (600) is applicable; otherwise, the actual D 正实测 and D 反实测 As a benchmark, correct S 阳极a and S 阳极b and verify D 正实测 and D 反实测 , until the discriminant formula 11 and the discriminant formula 12 are satisfied; Formula 11 and Formula 12 can be summarized as follows: the minimum error of the positive measured value based on the standard data of the metal coating is 100% ×〔( D Min正实测 - D 正标准 )÷ D 正标准 〕and the maximum error 100%×〔( D Max正实测 - D 正标准 )÷ D 正标准 〕; The minimum error of the measured value on the reverse side is 100%×〔( D Min反实测 - D 反标准 )÷ D 反标准 〕and the maximum error 100%×〔( D Max反实测 - D 反标准 )÷ D 反标准 〕, which can be expressed as the following formula 13 and formula 14: 0% < (( D 正实测 - D 正标准 ) ÷ D 正标准 〕×100%≤5%Formula 13 0% < (( D 反实测 - D 反标准 ) ÷ D 反标准 ] × 100% ≤ 5% Formula 14 Formula 13 and Formula 14 are used as threshold references. If they are satisfied, the selected anode spiral coil (200) is applicable. Otherwise, its diameter and length are corrected until the selection satisfies the applicable range of Formula 13 and Formula 14.

Images