A large-size ceramic package substrate splicing manufacturing method

Abstract

This invention proposes a method for manufacturing large-size ceramic packaging substrates by splicing, relating to the field of semiconductor technology. The method includes the following steps: S11, selecting a substrate with a thermal expansion coefficient of 6.7 × 10⁻⁶. ‑6 / ℃~8.03×10 ‑6 A large plate made of resin-glass fiber composite substrate with a temperature between [temperature range missing] °C is used as the encapsulation substrate. Multiple holes are cut into the large plate. S12: Multiple ceramic core plates are obtained and pre-embedded one-to-one within the corresponding holes, fixing the ceramic core plates to the hole walls. S17: According to the preset encapsulation unit requirements, the large plate is cut and split to form individual encapsulation units. This large-size ceramic encapsulation substrate splicing manufacturing method effectively solves the problem of low yield in traditional large-size ceramic substrate manufacturing.

Description

Technical Field

[0001] This invention relates to the field of semiconductor technology, and more specifically, to a method for manufacturing large-size ceramic packaging substrates by splicing. Background Technology

[0002] In the field of chip packaging, ceramic core boards are widely used due to their excellent insulation, low coefficient of thermal expansion, and high thermal conductivity. However, the size of a single ceramic core board is usually small, making it difficult to meet the demand for large-size substrates in large-scale chip packaging. Traditional methods for manufacturing large-size ceramic substrates have many problems, such as uncontrollable substrate yield, positional stability, and warpage during whole-board sintering, resulting in high production costs and difficulty in guaranteeing product quality. Therefore, an effective method is needed to splice small-size ceramic core boards into large boards to improve production efficiency and product quality. Summary of the Invention

[0003] The purpose of this invention is to provide a method for splicing and manufacturing large-size ceramic packaging substrates, which can effectively solve the problem of low yield in the traditional large-size ceramic substrate manufacturing process.

[0004] The embodiments of the present invention are implemented as follows: This application provides a method for manufacturing a large-size ceramic packaging substrate by splicing, including the following steps: S11, Select a coefficient of thermal expansion of 6.7×10. -6 / ℃~8.03×10 -6 A large plate made of resin-glass fiber composite substrate between / ℃ is used as the encapsulation substrate, and multiple holes are cut on the large plate. S12. Obtain multiple ceramic core plates and pre-embed them one by one in the holes to fix the ceramic core plates to the hole walls of their corresponding holes. S13. A number of interconnecting holes are provided on the ceramic core board, each interconnecting hole penetrating the upper and lower surfaces of the ceramic core board; an electroplated copper coating layer is provided on the upper and lower surfaces of the ceramic core board and on the hole walls of the interconnecting holes; the interconnecting holes are filled with ink. S14. An ABF composite layer is provided on the lower surface of the ceramic core board. The ABF composite layer includes several stacked ABF layers. A copper clad laminate layer is provided on the outside of each ABF layer. Several interconnected pads are formed on the copper clad laminate layer. Several grooves are on the copper clad laminate layer. Blind holes are provided on the ABF layer at each groove. Copper pillars are provided in the blind holes. S15. A solder resist layer is provided on the surface of the outer ABF layer; S16. A surface treatment layer is applied to the outside of the solder mask layer, and only the "pad area" of the solder mask layer is exposed on the surface treatment layer. S17. According to the preset packaging unit requirements, the large board is cut and split to form individual packaging units.

[0005] In some embodiments of the present invention, the specific steps of cutting multiple holes in the large plate are as follows: S111. First, use an ultraviolet laser to perform preliminary cutting on the large board, with the cutting accuracy controlled within ±0.02mm, to avoid burrs on the substrate edges caused by mechanical stamping; S112. Use a CNC milling cutter to finish the hole wall so that the hole wall roughness Ra≤0.8μm, and at the same time, chamfer the upper and lower edges of the hole. S113. Use a plasma cleaner to treat the finished hole walls to remove residual resin debris.

[0006] In some embodiments of the present invention, the ceramic core plate is 92 ceramic, 95 ceramic or 99 ceramic, and is made of alumina, aluminum nitride or silicon nitride material.

[0007] In some embodiments of the present invention, the distance between the hole wall and the ceramic core plate is 0.03 mm to 0.05 mm.

[0008] In some embodiments of the present invention, the specific step of S12 is as follows: filling the gap between the hole wall and the core plate with a low-viscosity epoxy adhesive, so that the ceramic core plate and the hole wall of the corresponding hole are fixed by the low-viscosity epoxy adhesive, wherein the viscosity range of the low-viscosity epoxy adhesive is 100 to 7000 mPa. Between s.

[0009] In some embodiments of the present invention, the specific steps for filling the gap between the hole wall and the core plate with a low-viscosity epoxy adhesive are as follows: Apply the low-viscosity epoxy adhesive evenly along the hole wall using a dispensing machine, ensuring that there are no bubbles or excess adhesive. After the low-viscosity epoxy adhesive has cured, apply a flexible silane coupling agent at the junction of the top edge of the ceramic core board and the large board.

[0010] In some embodiments of the present invention, the following steps are required before cutting the large plate in step S17: Inspect defective packaging units and discard them.

[0011] In some embodiments of the present invention, the specific steps for detecting and removing defective packaging units are as follows: The packaging units on the basic board are fully inspected by AOI equipment to identify defective units with problems such as cracked ceramic core boards, air bubbles in copper-clad laminates, and voids in the ABF layer. During cutting, defective units are avoided or separated individually, and only qualified units are cut and split.

[0012] Compared with the prior art, the embodiments of the present invention have at least the following advantages or beneficial effects: 1. This invention assembles small-sized ceramic core plates into a larger version, using materials with a thermal expansion coefficient of 6.7 × 10⁻⁶. -6 / ℃~8.03×10 -6 The resin-glass fiber composite substrate with a temperature range of / ℃ is used as the large board for packaging. This range of thermal expansion coefficient is close to that of the ceramic core board, which can reduce the warping problem caused by thermal stress cracking during subsequent copper clad laminate and ABF layer processing, and improve product yield. 2. This invention can flexibly meet different size requirements. Through modular splicing, it is easier to control the shrinkage rate, meet the requirements of film redistribution, and improve production efficiency and yield. Attached Figure Description

[0013] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0014] Figure 1 This is a schematic diagram of the structure of the large plate in an embodiment of the present invention; Figure 2 This is a schematic diagram of the hole opening in an embodiment of the present invention.

[0015] Icons: 1-Large board; 2-Hole. Detailed Implementation

[0016] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0017] Therefore, the following detailed description of the embodiments of the invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the invention without inventive effort are within the scope of protection of the invention.

[0018] Example Please refer to Figure 1 This embodiment provides a method for splicing and manufacturing large-size ceramic packaging substrates, including the following steps: S11, Select a coefficient of thermal expansion of 6.7×10. -6 / ℃~8.03×10 -6 The large board 1, made of a resin-glass fiber composite substrate with a temperature between ℃ and ℃, is used as the encapsulation substrate, and multiple holes 2 are cut into the large board 1. The above S11 step abandons the single resin board used in the traditional process and selects a resin-glass fiber composite substrate as the encapsulation substrate large board 1. Its coefficient of thermal expansion is closer to that of the ceramic core board, which can reduce the warping problem caused by thermal stress cracking during subsequent copper clad laminate and ABF layer processing, and improve product yield.

[0019] Specifically, in this embodiment, the thickness of the substrate is controlled between 0.8mm and 1.2mm, which ensures the structural strength after the hole 2 is opened, and avoids forming an excessive height difference with the ceramic core board.

[0020] Specifically, the steps for cutting multiple holes 2 on the large board 1 are as follows: First, use an ultraviolet laser for preliminary cutting, with the cutting accuracy controlled within ±0.02mm to avoid burrs on the substrate edges caused by mechanical stamping; then, use a CNC milling cutter to refine the hole walls so that the hole wall roughness Ra≤0.8μm, and at the same time, process chamfers on the upper and lower edges of the holes to prevent edge cracking when embedding the ceramic core board; after the holes are dug, use a plasma cleaning machine to treat the hole walls to remove residual resin debris and improve the adhesion of the subsequent bonding layer.

[0021] S12. Obtain multiple ceramic core plates and embed them one by one into the holes 2, so that the ceramic core plates are fixed to the hole walls of their corresponding holes.

[0022] The aforementioned ceramic core board is made of 92%, 95%, or 99% ceramic and is constructed from alumina, aluminum nitride, or silicon nitride. As the core substrate for carrying devices and transmitting signals in electronic equipment, the ceramic core board's unique material properties and performance advantages make it irreplaceable in high-precision, high-reliability electronic fields (such as aerospace, automotive electronics, and 5G communications).

[0023] Specifically, the ceramic core plate undergoes pretreatment to ensure its surface is clean and free of impurities. The distance between the hole wall of hole 2 and the ceramic core plate is 0.03mm to 0.05mm, which facilitates the insertion of the core plate, reserves space for the bonding layer, and simultaneously achieves pre-positioning of the core plate, preventing displacement during subsequent processing and ensuring positional stability. This effectively avoids yield problems caused by positional instability and improves the overall yield rate. The specific steps of S12 above are as follows: fill the gap between the hole wall and the core plate with low-viscosity epoxy adhesive, so that the ceramic core plate and the hole wall of the corresponding hole are fixed by the low-viscosity epoxy adhesive.

[0024] Specifically, the viscosity range of the aforementioned low-viscosity epoxy adhesive is 100–7000 mPa. Between s.

[0025] Specifically, the steps for filling the gap between the hole wall and the core board with low-viscosity epoxy adhesive are as follows: Apply the adhesive evenly along the hole wall using a dispensing machine, ensuring the low-viscosity epoxy adhesive is free of air bubbles and excess adhesive; after the low-viscosity epoxy adhesive has cured, apply a flexible silane coupling agent to the junction between the top edge of the ceramic core board and the large board 1. The flexible silane coupling agent enhances the bonding force between the core board and the subsequent copper clad laminate / ABF layer, and also buffers stress during thermal cycling, reducing the risk of cracking and further improving the yield rate.

[0026] S13. Several interconnecting holes are provided on the ceramic core board, each hole penetrating the upper and lower surfaces of the ceramic core board; an electroplated copper coating layer is provided on the upper and lower surfaces of the ceramic core board and on the hole walls; the interconnecting holes are filled with ink. Providing a copper coating on the surface of the ceramic core board is a key step in connecting the "insulation / high reliability substrate characteristics" of the ceramic core board with the "conductivity / interconnection requirements" of external electronic components; although the surface of the ceramic core board is hard, it has microscopic pores or defects, making it susceptible to damage from external environments (such as moisture and chemical corrosion) or mechanical stress (such as pressure during assembly). The copper coating acts as a "protective layer."

[0027] S14. An ABF composite layer is formed on the lower surface of the ceramic core board. The ABF composite layer consists of several stacked ABF layers. A copper-clad laminate layer is formed on the outer side of each ABF layer. Several interconnecting pads are formed on the copper-clad laminate layer. Several grooves are formed on the copper-clad laminate layer. Blind vias are formed on the ABF layer at each groove, and copper pillars are formed in the blind vias. The above-mentioned ABF composite layer makes up for the shortcomings of ceramic materials in high-density wiring, cost control and packaging compatibility, while retaining the core advantages of ceramic core boards. The ABF composite layer has good flexibility and compatibility. Passive components (resistors, capacitors, inductors) can be mounted on its surface or inside, or it can be used as a "transition layer" to connect the ceramic core board with other organic substrates (such as PCBs), solving the "rigid matching" problem between ceramic and organic materials.

[0028] S15. A solder resist layer is applied to the surface of the outer ABF layer. Applying a solder resist layer to the ABF layer is a crucial step in ensuring packaging reliability and achieving precise soldering. The solder resist layer protects the ABF layer and the corresponding copper wiring, isolating it from external damage and environmental corrosion. During the packaging process, soldering is performed on the copper pads of the ABF layer (e.g., chip bump soldering, solder ball placement, passive component mounting). The ABF layer itself has low hardness (Shore hardness D≈60~70), making it easily scratched during packaging handling and pressing. The solder resist layer, after curing, has high hardness (Shore hardness D≈85~90), resisting minor mechanical friction or impact and protecting the ABF layer and the corresponding copper wiring from physical damage. This solder resist layer, in conjunction with the following surface treatment layer, forms a window area. The exposed copper pads in the window area are roughened, significantly improving wettability with solder (contact angle ≤30°), reducing defects such as cold solder joints and poor soldering. Simultaneously, the solder resist layer prevents solder from diffusing into non-pad areas, ensuring the solder joint volume (e.g., solder ball). With a diameter deviation of ≤±10%, the shape meets packaging requirements, improving soldering reliability; the fully cured solder mask has excellent resistance to damp heat (no blistering or peeling of the coating and no corrosion of copper wiring after 1000 hours in an 85℃ / 85%RH environment) and chemical resistance (can withstand immersion in common cleaning agents such as soldering flux, alcohol, and acetone), preventing the ABF layer and copper wiring from failing due to environmental factors.

[0029] S16. A surface treatment layer is applied to the outside of the solder resist layer, with only the "pad area" of the solder resist layer exposed on the surface treatment layer. The copper pads of the solder resist layer are directly exposed to the air and are prone to rapid oxidation (forming CuO / Cu2O). The oxidized copper pads cannot form a reliable bond with solder (such as solder paste or gold wire). The packaging substrate needs to adapt to different application scenarios (such as the humid and hot environment of consumer electronics and the high and low temperature cycle of automotive electronics). The surface treatment layer can resist external environmental corrosion. Both the ABF composite layer (organic resin-based) and the solder resist layer (epoxy resin-based) are organic materials. The surface treatment layer can indirectly protect their structure. Different surface treatment layers can be matched with different welding / bonding processes, improving the versatility of the large board 1.

[0030] S17. According to the preset packaging unit requirements, the large board 1 is cut and split to form individual packaging units. Before cutting the large board 1 in S17, the following steps are required: detect defective packaging units and remove them. The specific steps for detecting and removing defective packaging units are as follows: perform a full inspection of the packaging units on the large board using AOI equipment to identify defective units with problems such as cracked ceramic core boards, air bubbles in copper-clad laminates, and voids in the ABF layer. During cutting, avoid or separate defective units, and only cut and split qualified units.

[0031] The aforementioned large board 1 typically mounts multiple ceramic core boards, which need to be cut and split into independent packaging units (including ceramic core boards and partial substrates). Each unit corresponds to the packaging requirements of 1 to 2 chips. The split units can directly enter subsequent processes such as chip mounting, wire bonding, and packaging, avoiding operational interference caused by the small spacing between units during the overall processing of the large panel, while meeting the differentiated packaging size requirements of different chip models.

[0032] Before cutting, a full inspection of the large panel can be performed using AOI equipment to identify defective units such as cracked ceramic core boards, air bubbles in the copper-clad laminate, and voids in the ABF layer. During cutting, defective units are selectively avoided or separated individually, and only qualified units are processed. This avoids scrapping the entire panel due to a few defective units, reducing material waste. This is especially beneficial for high-cost ceramic core boards, significantly controlling production costs. Different sizes of ceramic core boards can be embedded in the same panel. During cutting, the cutting path can be adjusted according to the encapsulation requirements of different core boards, adapting to the size flexibility of different encapsulation scenarios and enabling mass production of "one board with multiple specifications," thus improving production efficiency.

[0033] It should be noted that the ceramic core plate in this embodiment is a glass ceramic of type LTCC, HTCC or MLCC; or, in other embodiments, the ceramic core plate may also be an alumina ceramic of type 90 ceramic, 92 ceramic, 95 ceramic, 96 ceramic or 99 ceramic; or, the ceramic core plate may also be an aluminum nitride ceramic, silicon nitride ceramic, silicon carbide ceramic or diamond ceramic.

[0034] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A large-sized ceramic package substrate tiling manufacturing method, characterized by, Includes the following steps: S11, select a resin-glass fiber composite substrate with a thermal expansion coefficient between 6.7 x 10 -6 / ℃~8.03 x 10 -6 / ℃~8.03 x 10 -6 S11, select a resin-glass fiber composite substrate with a thermal expansion coefficient between 6.7 x 10 -6 / ℃~8.03 x 10 -6 / ℃~8.03 x 10 -6 S11, select a resin-glass fiber composite substrate with a thermal expansion coefficient between 6.7 x 10 S12. Obtain multiple ceramic core plates and pre-embed them one by one in the holes to fix the ceramic core plates to the hole walls of their corresponding holes. S13. A number of interconnecting holes are provided on the ceramic core board, each interconnecting hole penetrating the upper and lower surfaces of the ceramic core board; an electroplated copper coating layer is provided on the upper and lower surfaces of the ceramic core board and on the hole walls of the interconnecting holes; the interconnecting holes are filled with ink. S14. An ABF composite layer is provided on the lower surface of the ceramic core board. The ABF composite layer includes several stacked ABF layers. A copper clad laminate layer is provided on the outside of each ABF layer. Several interconnected pads are formed on the copper clad laminate layer. Several grooves are on the copper clad laminate layer. Blind holes are provided on the ABF layer at each groove. Copper pillars are provided in the blind holes. S15. A solder resist layer is provided on the surface of the outer ABF layer; S16. A surface treatment layer is applied to the outside of the solder mask layer, and only the "pad area" of the solder mask layer opening is exposed on the surface treatment layer. S17. According to the preset packaging unit requirements, the large board is cut and split to form individual packaging units.

2. The large-size ceramic package substrate tiling manufacturing method according to claim 1, wherein The specific steps for cutting multiple holes in the large plate are as follows: S111. First, use an ultraviolet laser to perform preliminary cutting on the large board, with the cutting accuracy controlled within ±0.02mm, to avoid burrs on the substrate edges caused by mechanical stamping; S112. Use a CNC milling cutter to finish the hole wall so that the hole wall roughness Ra≤0.8μm, and at the same time, chamfer the upper and lower edges of the hole. S113. Use a plasma cleaner to treat the finished hole walls to remove residual resin debris.

3. The large-sized ceramic package substrate tiling manufacturing method according to claim 1, wherein The ceramic core plate is made of 92, 95, or 99 ceramic and is made of alumina, aluminum nitride, or silicon nitride.

4. The large-sized ceramic package substrate tiling manufacturing method according to claim 1, wherein The distance between the hole wall and the ceramic core plate is 0.03mm to 0.05mm.

5. The large-size ceramic package substrate tiling manufacturing method according to claim 4, wherein The specific step of S12 is to fill the low-viscosity epoxy adhesive between the hole wall and the core plate gap, so that the ceramic core plate and the hole wall of the corresponding hole are fixed by the low-viscosity epoxy adhesive, and the viscosity of the low-viscosity epoxy adhesive is in the range of 100-7000 mPa s.

6. The large-sized ceramic package substrate tiling manufacturing method according to claim 5, wherein The specific steps for filling the gap between the hole wall and the core plate with low-viscosity epoxy adhesive are as follows: Apply the low-viscosity epoxy adhesive evenly along the hole wall using a dispensing machine, ensuring that there are no bubbles or excess adhesive. After the low-viscosity epoxy adhesive has cured, apply a flexible silane coupling agent at the junction of the top edge of the ceramic core board and the large board.

7. The large-size ceramic package substrate tiling manufacturing method according to claim 1, wherein Before cutting the large plate in step S17, the following steps are required: Inspect defective packaging units and discard them.

8. The large-size ceramic package substrate tiling manufacturing method according to claim 7, wherein The specific steps for detecting and removing defective packaging units are as follows: The packaging units on the large board are fully inspected by AOI equipment to identify defective units with problems such as cracked ceramic core boards, bubbles in copper-clad laminates, and voids in the ABF layer. During cutting, defective units are avoided or separated individually, and only qualified units are cut and split.

9. The large-size ceramic package substrate tiling manufacturing method according to claim 1, wherein The ceramic core board is made of electronic ceramics, glass ceramics, LTCC ceramics, HTCC ceramics, MLCC ceramics, alumina ceramics, aluminum nitride ceramics, silicon nitride ceramics, silicon carbide ceramics, or diamond ceramics.

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