System-level vehicle-mounted packaging substrate based on Tenting process and processing method thereof

Abstract

The invention discloses a Tenting process-based system-level vehicle-mounted packaging substrate and a processing method thereof. The processing method comprises the following steps of: providing a first PNL plate provided with an outer-layer copper foil and a through hole; a connecting copper layer is formed on the inner wall of the through hole, and the connecting copper layer extends to the outer copper foil and surrounds a preset area outside the two ports of the through hole to form a ring hole copper layer; performing resin hole plugging on the through hole; grinding two ports of the through hole, reducing copper of the ring hole copper layer and grinding the whole plate in sequence so as to form a micro step between the outer copper foil and the ring hole copper layer; a thickened copper layer is formed on the outer copper foil and the ring hole copper layer, an outer pattern is manufactured on the thickened copper layer, and a second PNL plate is obtained; and after solder mask treatment is carried out on the second PNL, gold plating treatment is carried out in the mode of arranging false gold plating fingers on the edge of the second PNL and between the SET and the SET by adopting the optimal control current density, and an outer layer pattern finished product with the thickness consistency is manufactured. According to the processing method, the size consistency of the outer-layer pattern finished product is remarkably improved, and the market requirement is met.

Description

Technical Field

[0001] The present invention relates to the technical field of circuit boards, and in particular to a system-level vehicle-mounted packaging substrate based on a Tenting process and a processing method thereof. Background Art

[0002] With the development of society and science and technology, automotive electronic products are becoming increasingly integrated. By stacking / integrating multiple functional chips on the same packaging substrate, not only can close integration be achieved and the product packaging size be reduced, but modules with different functions can also be customized according to different specific application scenarios, thereby improving application performance while significantly reducing power consumption and saving packaging substrate space.

[0003] Currently, the manufacturing of system-level automotive packaging substrates adheres to the following design requirements: mechanically creating through-holes; copper re-sinking after via plugging; and creating a matrix of wire bonding pads with a fine pitch between pads. Specifically, the upper dimension of the wire bonding pads must be ≤50μm, and the pad pitch must be ≥15μm. However, due to the limitations of the currently common tenting process, the yield of system-level automotive packaging substrates in mass production is low, and the pad consistency is poor.

[0004] In view of this, the present invention is proposed. Summary of the Invention

[0005] In order to overcome the above-mentioned defects, the present invention provides a system-level vehicle-mounted packaging substrate based on the Tenting process and a processing method thereof. The processing method is simple and reasonable, with high processing yield and low processing cost. In particular, it can significantly improve the dimensional consistency of the finished outer layer graphics, and well meet the use requirements of the system-level vehicle-mounted packaging substrate.

[0006] The technical solution adopted by the present invention to solve the technical problem is: a method for processing a system-level vehicle packaging substrate based on a tenting process, comprising: Providing a first PNL board, wherein the first PNL board has two outer copper foils disposed opposite to each other and a through hole penetrating the two outer copper foils; Performing through-hole electroplating on the first PNL board to form a connecting copper layer on the inner wall of the through-hole, wherein the connecting copper layer extends to cover the two outer copper foils and surrounds the predetermined areas outside the two ends of the through-hole, and the portion of the connecting copper layer covering the outer copper foils is defined as a ring-shaped copper layer; plugging the through hole with resin; Grinding the two ends of the through hole to grind off the resin protruding from the two ends of the through hole; then performing copper reduction treatment on the annular copper layer and then grinding the entire board to control the thickness of the annular copper layer to 4-6 μm, thereby forming a micro-step between the outer copper foil and the annular copper layer; forming a thickened copper layer with consistent thickness on the two outer copper foils and the annular copper layer through an electroplating process, and producing an outer layer pattern on the thickened copper layer through a circuit manufacturing process to obtain a second PNL board; The obtained second PNL board is subjected to solder mask treatment, and then subjected to electroplating gold treatment using a current density of less than 1.2 ASD and a processing method in which false gold-plated fingers are provided on the board edges and between the SETs of the obtained second PNL board, so as to obtain an outer layer pattern product with consistent thickness; the outer layer pattern product is provided with a plurality of wire bonding pad products arranged in a matrix, the upper width of the wire bonding pad products is 35 to 50 μm, the lower width is 40 to 55 μm, and the spacing between each two adjacent wire bonding pad products is 10 to 25 μm.

[0007] As a further improvement of the present invention, the specific processing parameters of the above-mentioned through-hole electroplating are: the current density is 1.0~1.3ASD; the first PNL board placed vertically is divided into the upper part, the middle part and the lower part of the board from top to bottom, and the electroplating efficiency corresponding to the upper part of the board is 105%~115%, the electroplating efficiency corresponding to the middle part of the board is 90%~100%, and the electroplating efficiency corresponding to the lower part of the board is 80%~90%, so that the copper thickness tolerance of the connecting copper layer is ±1.5μm.

[0008] As a further improvement of the present invention, before performing the above-mentioned through-hole electroplating, the first PNL board needs to be coated with a photosensitive resist, exposed, and developed in sequence to achieve coating of a film layer with a hollow window A on the two outer copper foils. At the same time, the two ends of the through hole and the preset areas on the two outer copper foils and surrounding the two ends of the through hole are respectively exposed to the hollow windows A. After completing the above-mentioned through-hole electroplating, the photosensitive resist is removed.

[0009] As a further improvement of the present invention, before performing the resin plugging, the first PNL board needs to be subjected to pre-treatment, ink dipping, exposure, and development in sequence, so that an ink layer with a hollow window B is respectively coated on the two outer copper foils, and at the same time, the two ends of the through hole and the annular copper layer are respectively exposed in the hollow windows B. After completing the resin plugging, a baking treatment at a temperature of 100°C to 120°C for 25 to 35 minutes is required to pre-cure the resin in the through hole; In addition, after the micro-steps are formed, a baking treatment at a temperature of 150° C. to 160° C. for 50 to 60 minutes is required to completely solidify the resin in the through-holes.

[0010] As a further improvement of the present invention, the electroplating processing parameters used in producing the thickened copper layer are: the current density is not greater than 1.2ASD; the vertically placed first PNL plate is divided into the upper part, the middle part and the lower part of the plate from top to bottom, and the electroplating efficiency corresponding to the upper part of the plate is 110% to 120%, the electroplating efficiency corresponding to the middle part of the plate is 95% to 105%, and the electroplating efficiency corresponding to the lower part of the plate is 85% to 95%, so that the copper thickness tolerance of the thickened copper layer is ±1.5μm.

[0011] As a further improvement of the present invention, the above-mentioned circuit manufacturing process includes the following steps: pre-treatment, resist coating, exposure, development, vacuum two-fluid etching and film stripping; wherein, when performing vacuum two-fluid etching, the surface of the etched wire bonding pad is set downward, and the etching spray pressure is 1.2 to 1.4 kg / cm 2 .

[0012] As a further improvement of the present invention, the outer layer pattern is provided with an outer layer circuit pattern and a pad pattern, the pad pattern is composed of a plurality of wire bonding pads arranged in a matrix, and the technical parameters of the pad pattern are: the upper width of the wire bonding pad is 25 to 40 μm, the lower width is 30 to 45 μm, and the spacing between each adjacent two wire bonding pads is 20 to 35 μm.

[0013] As a further improvement of the present invention, during the electro-gold treatment, a plurality of dummy gold-plated fingers are provided around the edges of the second PNL plate obtained and between the SETs, and the technical parameters of the dummy gold-plated fingers are as follows: the length of the dummy gold-plated fingers is 20±0.05 mm, the width is 2±0.05 mm, and the spacing between two adjacent dummy gold-plated fingers is 50±0.05 mm.

[0014] As a further improvement of the present invention, the manufacturing method of the first PNL board is as follows: providing an insulating intermediate layer and two composite copper layers, wherein both of the composite copper layers are provided with a carrier copper layer and an ultra-thin copper layer detachably provided on the carrier copper layer; The insulating intermediate layer and the two composite copper layers are stacked and pressed to obtain a substrate; wherein the ultra-thin copper layers of the two composite copper layers are respectively attached to the opposite sides of the insulating intermediate layer; The first PNL board is obtained by sequentially performing QR code marking, mechanical drilling, removal of the carrier copper layer and copper whole-board treatment on the substrate.

[0015] The present invention also provides a system-level vehicle-mounted packaging substrate based on the Tenting process, which is manufactured using the processing method of the system-level vehicle-mounted packaging substrate based on the Tenting process described in the present invention.

[0016] The beneficial effects of the present invention are as follows: ① The present invention significantly improves the dimensional consistency of the finished outer layer graphics through process innovation, especially the "through-hole electroplating process", "micro-step formation process", "thickening copper layer production process", and "electrometallurgy process" in the processing of system-level vehicle-mounted packaging substrates. After production verification, the dimensional consistency of the finished outer layer circuits and wire bonding pads obtained by the present invention has been improved by about 15%, which well meets the use requirements of system-level vehicle-mounted packaging substrates. ② The processing method of the system-level vehicle-mounted packaging substrate provided by the present invention is simple and reasonable, with a high processing yield and low processing cost, which is conducive to production implementation. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 This is a flowchart of a method for processing a system-level vehicle packaging substrate based on a Tenting process according to Example 1 of the present invention; Figure 2 Schematic diagram of the cross-sectional structure of the substrate in Example 1 of the present invention; Figure 3 Schematic diagram of the cross-sectional structure of the first PNL plate obtained in Example 1 of the present invention; Figure 4 Schematic diagram of the cross-sectional structure of the board obtained after the film layer is coated on the first PNL board in Example 1 of the present invention; Figure 5 Schematic diagram of the cross-sectional structure of the board obtained after through-hole electroplating is completed on the first PNL board in Example 1 of the present invention; Figure 6 Schematic diagram of the cross-sectional structure of the board obtained after the ink layer is coated on the first PNL board in Example 1 of the present invention; Figure 7 Schematic diagram of the cross-sectional structure of the board obtained after the through holes are plugged with resin in Example 1 of the present invention; Figure 8 Schematic diagram of the cross-sectional structure of the board obtained after the first PNL board is subjected to two-stage grinding and copper reduction treatment in Example 1 of the present invention; Figure 9 for Figure 8 A schematic diagram of the enlarged structure of part A shown in FIG; Figure 10 Schematic diagram of the cross-sectional structure of a board obtained after a thickened copper layer is obtained by electroplating in Example 1 of the present invention; Figure 11 Schematic diagram of the cross-sectional structure of the second PNL plate obtained in Example 1 of the present invention; Figure 12 Schematic diagram of the cross-sectional structure of the system-level vehicle packaging substrate obtained in Example 1 of the present invention.

[0018] The following description is made with reference to the accompanying drawings: 1. First PNL board; 10. Outer copper foil; 11. Through hole; 12. Connecting copper layer; 120. Ring copper layer; 13. Insulating intermediate layer; 14. Carrier copper layer; 2. Thickened copper layer; 3. Outer layer pattern; 30. Outer layer circuit pattern; 31. Pad pattern; 4. Film layer; 40. Hollow window A; 5. Ink layer; 50. Hollow window B; 6. Resin; 7. Nickel-gold layer; 8. Solder mask layer. DETAILED DESCRIPTION

[0019] The preferred embodiments of the present invention are described in detail below with reference to the accompanying drawings.

[0020] Embodiment 1:

[0021] Please see the attached Figure 1 To the attached Figure 12 As shown, this embodiment 1 provides a method for processing a system-level vehicle-mounted packaging substrate based on a Tenting process, including the following processing steps: S1: providing a first PNL board 1 , wherein the first PNL board 1 is provided with two outer copper foils 10 arranged opposite to each other and a through hole 11 penetrating the two outer copper foils 10 .

[0022] Specifically, in this embodiment, the first PNL plate 1 is preferably manufactured by: S10: providing an insulating intermediate layer 13 and two composite copper layers, wherein both composite copper layers are provided with a carrier copper layer 14 and an ultra-thin copper layer detachably provided on the carrier copper layer 14 .

[0023] Among them, the insulating intermediate layer 13 can adopt at least two semi-cured sheets, and the composite copper layer is made by depositing the ultra-thin copper layer on the carrier copper layer 14 treated with a chemical solution using an electroplating process, and the thickness of the carrier copper layer 14 is preferably 17±2μm, the thickness of the ultra-thin copper layer is optimally controlled to be 2~3μm, and the copper tooth Rz value is optimally controlled to be no more than 0.8μm.

[0024] Note: The chemical treatment of the carrier copper layer 14 prior to electrodeposition of the ultra-thin copper layer ensures a predetermined peeling force between the carrier copper layer 14 and the ultra-thin copper layer, while also enabling a good mechanical separation between the carrier copper layer 14 and the ultra-thin copper layer. This is a conventional technique in the field of circuit boards and will not be described in detail here.

[0025] S11: After the insulating intermediate layer 13 and the two composite copper layers are stacked and pressed together, a substrate is obtained; wherein the ultra-thin copper layers of the two composite copper layers are respectively attached to the opposite sides of the insulating intermediate layer 13; for details, please refer to the attached Figure 2 shown.

[0026] The pressing process adopts an electric heating pressing method, and the specific processing parameters of the pressing process are: heating rate ≥ 8°C / min, maximum pressing temperature ≥ 230°C, and maximum pressing pressure ≥ 450Psi.

[0027] It is understandable that by adopting the pressing treatment method, not only can the ultra-thin copper layer and the insulating intermediate layer be easily and firmly combined, but also plates with different thickness requirements can be produced according to product design requirements.

[0028] S12: In combination with the ERP system, a QR code printer is used to print a unique PNL QR code on the edge area of ​​the substrate.

[0029] S13: Drilling the required through holes 11 on the substrate using a mechanical drill. It is understandable that both ends of the through holes 11 penetrate the carrier copper layers 14 on the two composite copper layers respectively.

[0030] S14: removing the carrier copper layer 14 on the two composite copper layers by mechanical stripping.

[0031] S15: After removing the glue residue on the wall of the through hole 11, the substrate is subjected to a copper treatment (i.e., a thin copper layer is deposited on the surface of the two ultra-thin copper layers and the inner wall of the through hole 11), thus obtaining the first PNL board 1. Figure 3 As shown, the first PNL board 1 is provided with an insulating intermediate layer 13, two outer copper foils 10 (composed of an ultra-thin copper layer and thin copper deposited thereon) respectively attached to opposite sides of the insulating intermediate layer 13, and a through hole 11 penetrating the insulating intermediate layer 13 and the two outer copper foils 10, with thin copper also deposited on the inner wall of the through hole 11 (which can be understood as metallization treatment).

[0032] Of course, in actual application, the first PNL board 1 can also adopt other implementation structures, and this application does not impose any restrictions. The specific implementation structure is determined according to the design requirements of the circuit board product.

[0033] S2: Through-hole electroplating is performed on the first PNL board 1 to form a connecting copper layer 12 on the inner wall of the through-hole 11. The connecting copper layer 12 extends to cover the two outer copper foils 10 and surrounds the preset area outside the two ends of the through-hole 11. It is understandable that the specific size of the "preset area" is determined according to the design requirements of the circuit board product, and this application does not impose any restrictions. In addition, in order to facilitate the description of the processing method of the system-level vehicle-mounted packaging substrate described in this application, the portion of the connecting copper layer 12 covering the outer copper foil 10 is also defined as the ring-hole copper layer 120. For details, please refer to the attached Figure 5 shown.

[0034] Specifically, the preferred implementation method of S2 is: S20: The first PNL board 1 is sequentially coated with a photosensitive resist, exposed, and developed, so that a film layer 4 with a hollow window A40 is respectively coated on the two outer copper foils 10. At the same time, the two ends of the through hole 11 and the preset areas on the two outer copper foils 10 and respectively surrounding the two ends of the through hole 11 are respectively exposed from the hollow windows A40.

[0035] Among them, the above-mentioned anti-plating photosensitive film treatment is to stick the anti-plating photosensitive dry film on the two outer copper foils 10 through a vacuum film laminating machine; the above-mentioned exposure treatment is to expose part of the anti-plating photosensitive dry film according to the operation data through an LDI exposure machine; the above-mentioned development treatment is to remove the unexposed area of ​​the anti-plating photosensitive dry film, specifically, to remove the anti-plating photosensitive dry film at the two ends of the through hole 11 and at the preset areas on the two outer copper foils 10 and respectively surrounding the two ends of the through hole 11, so as to form the hollow window A40; at that time, the film layer 4 with the hollow window A40 can be respectively covered on the two outer copper foils 10, and the details can be referred to the attached. Figure 4 shown.

[0036] S21: The first PNL board 1 is subjected to through-hole electroplating by using a pattern-controlled through-hole electroplating process, so as to plate the connecting copper layer 12 on the inner wall of the through-hole 11 and the two outer copper foils 10 and on the preset areas surrounding the two ends of the through-hole 11. Figure 5As shown; wherein, the specific processing parameters of the above-mentioned through-hole electroplating are: ① the current density is 1.0~1.3ASD, which is 20% lower than the current density in the traditional graphic electroplating process; ② if the first PNL board 1 placed vertically is divided into the upper part, the middle part and the lower part of the board from top to bottom, the electroplating efficiency corresponding to the upper part of the board is 105%~115%, the electroplating efficiency corresponding to the middle part of the board is 90%~100%, and the electroplating efficiency corresponding to the lower part of the board is 80%~90%. , that is: when performing through-hole electroplating, the electroplating efficiency decreases in a step-by-step manner along the vertical direction of the first PNL plate 1, which is inversely related to the distribution of electric lines; ③ The jet pressure is increased by 15% to 25% compared with the jet pressure in the traditional graphic electroplating process; thereby achieving the copper thickness tolerance of the connecting copper layer 12 being optimized to ±1.5μm, effectively improving the thickness consistency of the connecting copper layer 12, which also provides technical support for obtaining a thickened copper layer 2 with good thickness consistency in the subsequent process.

[0037] Explanation: ① It is well known that the calculation formula for the thickness of the electroplated copper layer in the field of circuit board technology is: Electroplated copper layer thickness (μm) = current density (ASF) × electroplating time (min) × electroplating efficiency × electroplating coefficient; where current density is the number of amperes of current passing through a unit area per square foot; electroplating time is the duration of the electroplating process; electroplating efficiency is the actual utilization efficiency of the current during the electroplating process; and the electroplating coefficient is a constant of 0.0202. It is understandable that the electroplating efficiency can have a significant impact on the thickness of the electroplated copper layer. ② In order to achieve differentiated control of the electroplating efficiency at various locations of the connecting copper layer 12, this embodiment uses three rectifiers to separately manage the electroplating efficiency and current density applied to the upper, middle, and lower portions of the board.

[0038] S22: After the through-hole electroplating is completed, the anti-plating photosensitive dry film on the outer copper foil 10 is removed by a combination of immersion and spraying in a strong alkaline solution.

[0039] S3: First, the first PNL board 1 is subjected to pre-treatment, ink dipping, exposure and development treatment in sequence, so as to realize that the ink layer 5 with the hollow window B50 is respectively covered on the two outer copper foils 10. At the same time, the two ends of the through hole 11 and the annular copper layer 120 are respectively exposed in the hollow window B50. Figure 6 As shown; it can be understood that the ink layer 5 is used as a protective layer to protect the copper surface of the first PNL board 1 during the following grinding and copper reduction operations; then a vacuum resin plugging machine is used to plug the through hole 11 with resin to fill and solidify the through hole 11 with resin 6, which can be seen in the attached Figure 7and then baking at a temperature of 100°C to 120°C for 25 to 35 minutes to pre-cure the resin 6 within the through hole 11.

[0040] Among them, the above-mentioned pre-treatment is to clean, dry and other treatments on the first PNL board 1; the above-mentioned ink dipping is to immerse the first PNL board 1 in ink to cover the ink layer 5 on the first PNL board 1; the above-mentioned exposure treatment is to expose part of the ink layer 5 through the LDI exposure machine according to the operation data; the above-mentioned development treatment is to remove the unexposed area of ​​the ink layer 5, specifically to remove the ink layer 5 on the inner wall of the through hole 11 and the annular copper layer 120 to form a hollow window B50; at that time, the ink layer 5 with the hollow window B50 can be respectively covered on the two outer copper foils 10.

[0041] S4: First, the two ends of the through hole 11 are ground with a ceramic brush wheel to grind off the resin protruding from the two ends of the through hole 11; then, the portion of the connecting copper layer 12 (i.e., the annular copper layer 120) covering the outer copper foil 10 is subjected to copper reduction treatment by an etching process (specifically, a micro-etching process), and then the entire first PNL board 1 is ground with a mechanical grinding device to control the thickness of the annular copper layer 120 to be 4-6 μm, thereby forming a micro-step between the outer copper foil 10 and the annular copper layer 120 (for details, please refer to the attached Figure 8 and 9 As shown), it is ensured that the thickness consistency of the thickened copper layer 2 produced in the subsequent process is greatly improved.

[0042] In addition, after forming the micro-steps, this embodiment also removes the ink layer 5 by combining liquid immersion, spraying and shaking, and performs a baking treatment at a temperature of 150°C to 160°C for 50 to 60 minutes to completely cure the resin 6 in the through hole 11.

[0043] It can be understood that the present application can effectively overcome the problem of poor consistency of micro-steps and copper thickness caused by multiple exposure alignment offset problems by adopting the above-mentioned two-stage grinding and copper reduction treatment combination, and significantly improve the consistency of micro-steps and copper thickness.

[0044] S5: forming a thickened copper layer 2 with a consistent thickness on the two outer copper foils 10 and the annular copper layer 120 thereon by electroplating. Figure 10 Then, an outer layer pattern 3 is produced on the thickened copper layer 2 by a circuit production process to obtain a second PNL board; see the attached Figure 11 shown.

[0045] Specifically, in this embodiment, the thickened copper layer 2 is formed on the two outer copper foils 10 and the ring-hole copper layer 120 using the whole-plate hole-filling electroplating process, and the specific processing parameters of the whole-plate hole-filling electroplating process are as follows: ① the current density is not greater than 1.2ASD, which is 20% lower than that of the traditional hole-filling electroplating process; ② if the first PNL board 1 placed vertically is divided into the upper part, the middle part and the lower part of the board from top to bottom, and the electroplating efficiency corresponding to the upper part of the board is 110% to 120 %, the plating efficiency corresponding to the middle of the board is 95%-105%, and the plating efficiency corresponding to the lower part of the board is 85%-95%. That is, during the above-mentioned full-board via-filling electroplating process, the electroplating efficiency decreases in a step-by-step manner along the vertical direction of the first PNL board 1, inversely related to the distribution of electric lines of force. This achieves an optimized copper thickness tolerance of the thickened copper layer 2 of ±1.5μm, achieving excellent thickness consistency and providing excellent technical support and guarantee for the subsequent production of precision circuits. Furthermore, this whole-board via-filling electroplating process overcomes the problem of poor wire bonding caused by grinding marks generated by the aforementioned S4.

[0046] Similar to the above S21, in order to achieve differentiated control of the electroplating efficiency at various locations of the thickened copper layer 2, this embodiment also utilizes three rectifiers to respectively manage the electroplating efficiency and current density applied to the upper, middle, and lower portions of the plate.

[0047] In addition, before performing the vertical electroplating process, this embodiment also roughens the resin 6 at both ends of the through-hole 11 and performs a copper treatment on the outer copper foil 10 and the annular copper layer 120 to enhance the stability of the thickened copper layer 2 when bonded to the resin 6, the outer copper foil 10, and the annular copper layer 120. Furthermore, the thickness of the thickened copper layer 2 is determined based on the design requirements of the circuit board product and is not a limiting requirement in this embodiment.

[0048] The circuit production process preferably adopted in the present embodiment when producing the outer layer pattern 3 is: including pre-treatment, anti-corrosion photosensitive film coating, exposure, development, vacuum two-fluid etching and film stripping processes performed in sequence, wherein the pre-treatment is to clean and dry the first PNL board 1; the anti-corrosion photosensitive film coating is to apply the anti-corrosion photosensitive dry film to the two thickened copper layers 2 by a vacuum film laminator; the exposure is to expose part of the anti-corrosion photosensitive dry film by an LDI exposure machine according to the operation data; the development is to remove the unexposed area of ​​the anti-corrosion photosensitive dry film; the vacuum two-fluid etching is to use a vacuum two-fluid etching device to vacuum etch the part of the thickened copper layer 2 exposed outside the anti-corrosion photosensitive dry film to obtain the outer layer pattern 3; in addition, when performing the vacuum two-fluid etching process, the surface of the etched wire bonding pad is set facing downward, and the etching spray pressure is optimally controlled to be 1.2-1.4 kg / cm 2; The above-mentioned film removal: is to use a strong alkaline solution to completely remove the anti-etching photosensitive dry film.

[0049] Through the above circuit manufacturing process, the structure and technical parameters of the outer layer pattern 3 obtained in this embodiment are as follows: Figure 11 As shown, the outer layer pattern 3 is provided with an outer layer circuit pattern 30 and a pad pattern 31. The line width of the outer layer circuit pattern 30 is 20-40 μm and the line spacing is 20-40 μm. The pad pattern 31 is composed of a plurality of wire bonding pads arranged in a matrix, and the upper width of the wire bonding pad is 25-40 μm and the lower width is 30-45 μm. The spacing between each two adjacent wire bonding pads is 20-35 μm.

[0050] Supplementary Notes: ① In the circuit board industry, the upper portion of the vertically arranged wire bonding pad is generally referred to as the "upper section," and the lower portion of the wire bonding pad is referred to as the "lower section." ② Based on circuit board product design requirements, the outer layer circuit pattern 30 is formed on each of the two thickened copper layers 2, and the pad pattern 31 is formed on at least one of the two thickened copper layers 2.

[0051] In addition, after completing the above-mentioned circuit production, this embodiment also performs AOI inspection and confirmation on the appearance of the obtained outer layer pattern 3. If there is any bad information, it will be uploaded and stored in combination with the PNL QR code.

[0052] S6: The obtained second PNL board is subjected to solder mask treatment, and then subjected to electroplating treatment using a current density of less than 1.2ASD (50% to 70% of the current density in a conventional electroplating gold treatment process), and fake gold-plated fingers are provided around the edges of the second PNL board and between the SETs, to obtain an outer layer pattern product with consistent thickness; wherein the outer layer pattern product is provided with a plurality of wire bonding pads arranged in a matrix, the upper width of the wire bonding pads being 35 to 50 μm, the lower width being 40 to 55 μm, and the spacing between each two adjacent wire bonding pads being 10 to 25 μm; for details, please refer to the attached Figure 12 shown.

[0053] Specifically, in this embodiment, the second PNL board is sequentially subjected to pre-treatment, solder mask coating, pre-baking, exposure, development, and post-baking to achieve a solder mask layer 8 for protection on the non-soldering area of ​​the resulting second PNL board, and to remove the solder mask layer from the soldering area of ​​the resulting second PNL board. The aforementioned solder mask process is commonly used in the field of circuit boards and is common knowledge, so it will not be described in detail here.

[0054] In this embodiment, the second PNL board after the solder mask treatment is processed is subjected to pre-treatment, anti-plating photosensitive film coating, exposure, development, electroplating nickel layer and electroplating gold layer processing in sequence to realize the plating of nickel-gold layer 7 on the outer layer pattern 3; wherein, the above-mentioned pre-treatment is to clean and dry the second PNL board; the above-mentioned anti-plating photosensitive film coating is to apply the anti-plating photosensitive dry film to the two thickened copper layers 2 (including the outer layer pattern 3) by a vacuum laminating machine; the above-mentioned exposure is to expose part of the anti-plating photosensitive dry film by an LDI exposure machine according to the operation data; the above-mentioned development is to remove the unexposed area of ​​the anti-plating photosensitive dry film, specifically, to remove the anti-plating photosensitive dry film coated on the pad pattern 31 and the surrounding set area (determined according to the circuit board product design requirements), and to remove the anti-plating photosensitive dry film coated on the surface of the set area of ​​the outer layer circuit pattern 30; the above-mentioned electroplating nickel layer and electroplating Gold layer treatment: A nickel layer and a gold layer are plated in sequence on the area of ​​the outer layer pattern 3 not covered by the resist photosensitive dry film using an electroplating process (i.e., the gold layer is covered on the nickel layer, and the nickel layer and the gold layer are conventionally referred to as the nickel-gold layer 7 in the industry); in addition, when performing the above-mentioned electroplating nickel layer and electroplating gold layer treatment, this embodiment optimizes the current density to be below 1.2ASD, which is 30% to 50% lower than that of conventional electroplating gold operation; and a number of dummy gold-plated fingers are respectively provided around the edge of the obtained second PNL board and between the SETs, and the technical parameters of the dummy gold-plated fingers are: the finger length of the dummy gold-plated fingers is 20±0.05mm, the finger width is 2±0.05mm, and the spacing between each two adjacent dummy gold-plated fingers is 50±0.05mm; thereby greatly improving the consistency of the thickness of the nickel-gold layer 7. After production verification, the thickness consistency of the nickel-gold layer 7 obtained in this embodiment is improved by 15%. Supplementary explanation: In the circuit board industry, PNL, SET, and PCS are commonly used units. A PNL consists of a single or multiple SETs, and a SET consists of a single or multiple PCSs.

[0055] In addition, based on the above description of the structure and technical parameters of the outer layer circuit pattern 30, after electroplating, the structure and technical parameters of the outer layer pattern product obtained are as follows: Figure 12 As shown, the outer layer circuit pattern 30 and the nickel-gold layer 7 thereon together constitute the outer layer circuit finished product, and the technical parameters of the outer layer circuit finished product are: line width of 20 to 40 μm, line spacing of 20 to 40 μm; the pad pattern 31 and the nickel-gold layer 7 thereon together constitute the pad pattern finished product, and the technical parameters of the pad pattern finished product are: the upper width of the wire bonding pad finished product is 35 to 50 μm, the lower width is 40 to 55 μm, and the spacing between each adjacent two wire bonding pad finished products is 10 to 25 μm.

[0056] In addition, according to the product design requirements, this embodiment also performs conventional molding, electrical testing, finished product inspection, packaging and shipping on the second PNL board after the electrometallurgical treatment, so as to complete the subsequent production of the system-level vehicle-mounted packaging substrate product based on the Tenting process. The structural diagram of the obtained system-level vehicle-mounted packaging substrate product is shown in the attached figure. Figure 12 shown.

[0057] From the above, it can be seen that this application has significantly improved the dimensional consistency of the finished outer layer graphics through process innovation, especially the innovation of "through-hole electroplating process", "process for forming micro-steps", "process for making thickened copper layer", and "electro-gold process". After production verification, the dimensional consistency of the finished outer layer circuit products and wire bonding pad products obtained in this application has been improved by 15%, which well meets the use requirements of system-level automotive packaging substrates.

[0058] Example 2:

[0059] This embodiment 2 provides a system-level vehicle-mounted packaging substrate based on the Tenting process, which is manufactured using the processing method of the system-level vehicle-mounted packaging substrate based on the Tenting process described in the above embodiment 1.

[0060] Specifically, the specific structure of the system-level vehicle-mounted packaging substrate in this embodiment 2 is as follows: Figure 12 As shown, the system-level vehicle-mounted packaging substrate includes an insulating intermediate layer 13 and two outer pattern products respectively arranged on opposite sides of the insulating intermediate layer 13. The outer pattern product is provided with an outer circuit product and a pad pattern product, and the line width of the outer circuit product is 20 to 40 μm and the line spacing is 20 to 40 μm. The pad pattern product is composed of a plurality of wire bonding pad products arranged in a matrix, and the upper width of the wire bonding pad product is 35 to 50 μm and the lower width is 40 to 55 μm. The spacing between each two adjacent wire bonding pad products is 10 to 25 μm; in addition, the two outer circuit products are also electrically connected through the connecting copper layer 12.

[0061] As can be seen from the above, the dimensional consistency of the finished outer layer graphics in the system-level vehicle packaging substrate described in this embodiment 2 is very high, which is 15% higher than the existing technology, and well meets the market demand.

[0062] Finally, the prefixes "first", "second", etc. in the component names in this application description (such as the first PNL plate, the second PNL plate, etc.), and the suffixes "A", "B", etc. in the component names (such as hollow window A, hollow window B, etc.) are only for the convenience of description and are not intended to limit the scope of implementation of the patent of this invention.

[0063] In the above description, many specific details are set forth in order to fully understand the present invention. However, the above description is only a preferred embodiment of the present invention. The present invention can be implemented in many other ways different from those described herein, so the present invention is not limited to the specific implementation disclosed above. At the same time, any person skilled in the art can make many possible changes and modifications to the technical solution of the present invention using the methods and technical contents disclosed above without departing from the scope of the technical solution of the present invention, or modify it into an equivalent embodiment of equivalent changes. Any simple modification, equivalent change and modification made to the above embodiment based on the technical essence of the present invention without departing from the content of the technical solution of the present invention still falls within the scope of protection of the technical solution of the present invention.

Claims

1. A method for processing a system-level vehicle packaging substrate based on a tenting process, characterized by: include: Providing a first PNL board (1), wherein the first PNL board (1) is provided with two outer copper foils (10) arranged opposite to each other and a through hole (11) penetrating the two outer copper foils (10); Performing through-hole electroplating on the first PNL board (1) to form a connecting copper layer (12) on the inner wall of the through-hole (11), wherein the connecting copper layer (12) extends to cover the two outer copper foils (10) and respectively surrounds a preset area outside the two ends of the through-hole (11), and the portion of the connecting copper layer (12) covering the outer copper foils (10) is defined as a ring-hole copper layer; Filling the through hole (11) with resin; Grinding the two ends of the through hole (11) to grind away the resin protruding from the two ends of the through hole (11); then performing copper reduction treatment on the annular copper layer and then grinding the entire board to control the thickness of the annular copper layer to 4 to 6 μm, thereby forming a micro-step between the outer copper foil (10) and the annular copper layer; A thickened copper layer (2) with consistent thickness is formed on the two outer copper foils (10) and the annular copper layer through an electroplating process, and an outer layer pattern (3) is produced on the thickened copper layer (2) through a circuit production process; thus obtaining a second PNL board; The obtained second PNL board is subjected to solder mask treatment, and then subjected to electroplating gold treatment using a current density of less than 1.2 ASD and a processing method in which false gold-plated fingers are provided on the board edges and between the SETs of the obtained second PNL board, so as to obtain an outer layer pattern product with consistent thickness; the outer layer pattern product is provided with a plurality of wire bonding pad products arranged in a matrix, the upper width of the wire bonding pad products is 35 to 50 μm, the lower width is 40 to 55 μm, and the spacing between each two adjacent wire bonding pad products is 10 to 25 μm.

2. The method for processing a system-on-vehicle package substrate based on a tenting process according to claim 1, wherein: The specific processing parameters of the through-hole electroplating are as follows: the current density is 1.0 to 1.3 ASD; the first PNL plate (1) placed vertically is divided into an upper plate portion, a middle plate portion and a lower plate portion from top to bottom, and the electroplating efficiency corresponding to the upper plate portion is 105% to 115%, the electroplating efficiency corresponding to the middle plate portion is 90% to 100%, and the electroplating efficiency corresponding to the lower plate portion is 80% to 90%, so that the copper thickness tolerance of the connecting copper layer (12) is ±1.5 μm.

3. The method for processing a system-on-vehicle package substrate based on a tenting process according to claim 1, wherein: Before the above-mentioned through-hole electroplating is performed, the first PNL board (1) needs to be coated with a photosensitive film, exposed and developed in sequence, so as to respectively coat the two outer copper foils (10) with a film layer having a hollow window A, and at the same time, the two ends of the through hole (11) and the preset areas on the two outer copper foils (10) and respectively surrounding the two ends of the through hole (11) are respectively exposed to the hollow window A; After the through-hole electroplating is completed, the resist photosensitive film is removed.

4. The method for processing a system-on-vehicle package substrate based on a tenting process according to claim 1, wherein: Before performing the above-mentioned resin plugging, the first PNL board (1) needs to be subjected to pre-treatment, ink dipping, exposure and development treatment in sequence, so as to respectively cover the two outer copper foils (10) with ink layers having hollow windows B, and at the same time, the two ends of the through hole (11) and the annular copper layer are respectively exposed in the hollow windows B; After completing the resin plugging, a baking treatment at a temperature of 100°C to 120°C is required for 25 to 35 minutes to pre-cure the resin in the through hole (11); In addition, after the micro-steps are formed, a baking treatment at a temperature of 150° C. to 160° C. is required for 50 to 60 minutes to completely solidify the resin in the through hole (11).

5. The method for processing a system-in-vehicle package substrate based on a tenting process according to claim 1, wherein: The electroplating processing parameters used when making the thickened copper layer (2) are as follows: the current density is not greater than 1.2ASD; the first PNL plate (1) placed vertically is divided into an upper plate portion, a middle plate portion and a lower plate portion from top to bottom, and the electroplating efficiency corresponding to the upper plate portion is 110% to 120%, the electroplating efficiency corresponding to the middle plate portion is 95% to 105%, and the electroplating efficiency corresponding to the lower plate portion is 85% to 95%, so that the copper thickness tolerance of the thickened copper layer (2) is ±1.5μm.

6. The method for processing a system-on-vehicle package substrate based on a tenting process according to claim 1, wherein: The above-mentioned circuit manufacturing process includes the following steps: pre-treatment, resist coating, exposure, development, vacuum two-fluid etching and film stripping. During the vacuum two-fluid etching process, the surface of the etched wire bonding pad is set downward, and the etching spray pressure is 1.2-1.4 kg / cm 2 .

7. The method for processing a system-in-vehicle package substrate based on a tenting process according to claim 6, wherein: The outer layer pattern (3) is provided with an outer layer circuit pattern (30) and a pad pattern (31), wherein the pad pattern (31) is composed of a plurality of wire bonding pads arranged in a matrix, and the technical parameters of the pad pattern (31) are as follows: the upper width of the wire bonding pad is 25 to 40 μm, the lower width is 30 to 45 μm, and the spacing between each two adjacent wire bonding pads is 20 to 35 μm.

8. The method for processing a system-in-vehicle package substrate based on a tenting process according to claim 1, wherein: During the electro-gold treatment, a number of dummy gold-plated fingers are arranged around the edges of the second PNL board and between the SETs. The technical parameters of the dummy gold-plated fingers are as follows: the length of the dummy gold-plated fingers is 20±0.05mm, the width is 2±0.05mm, and the spacing between each two adjacent dummy gold-plated fingers is 50±0.05mm.

9. The method for processing a system-in-vehicle package substrate based on a tenting process according to claim 1, wherein: The manufacturing method of the first PNL plate (1) is: Providing an insulating intermediate layer (13) and two composite copper layers, wherein both composite copper layers are provided with a carrier copper layer (14) and an ultra-thin copper layer detachably provided on the carrier copper layer (14); The insulating intermediate layer (13) and the two composite copper layers are stacked and pressed to obtain a substrate; wherein the ultra-thin copper layers of the two composite copper layers are respectively attached to the opposite sides of the insulating intermediate layer (13); The first PNL board (1) is obtained by sequentially performing QR code marking, mechanical drilling, removal of the carrier copper layer, and copper whole-board treatment on the substrate.

10. A system-level vehicle packaging substrate based on a tenting process, characterized by: The system is manufactured by using the processing method of the system-level vehicle-mounted packaging substrate based on the Tenting process according to any one of claims 1 to 9.

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