AMB product with high recognition degree of PR target spot and preparation method of AMB product

Abstract

The invention discloses an AMB product with a high-recognition-degree PR target spot and a preparation method of the AMB product. The preparation method comprises the following steps: S1, preparing a copper-clad ceramic substrate; manufacturing a copper-clad ceramic substrate by using an active metal brazing process; s2, manufacturing a copper surface PR target spot etching hole; manufacturing a copper surface PR target spot etching hole through one-time etching by utilizing a chemical method; s3, removing solder in the etching hole of the PR target spot; manufacturing a copper surface PR target spot etching hole through secondary etching by using a chemical method; removing the solder in the etching hole of the PR target spot; s4, performing ceramic laser marking in the PR target spot etching hole; performing laser marking on the ceramic in the PR target spot etching hole by using laser; s5, automatic optical detection; the cleaned AMB product is subjected to target spot recognition through an AOI automatic optical detector, the PR target spot machining surface is converted from the original copper surface to the ceramic surface, and the recognition degree of the PR target spot is remarkably increased.

Description

Technical Field

[0001] The present invention belongs to the technical field of semiconductor packaging, and in particular relates to an AMB product with high recognition PR target and a preparation method thereof. Background Art

[0002] AMB ceramic substrates are bonded by chemical reaction between ceramic and active metal solder paste at high temperature, so they have higher bonding strength and better reliability, and are extremely suitable for connectors or scenarios with large current carrying capacity and high heat dissipation requirements. AMB copper-clad ceramic substrate materials are widely used in semiconductor device packaging with high power and high heat dissipation requirements due to their high thermal conductivity and high insulation properties. AMB products need to be aligned by identifying the PR target of AMB products during downstream chip sintering and wire bonding processes.

[0003] like Figure 1 , Figure 3-4 The existing AMB product target manufacturing process shown is to perform laser marking on the copper surface after copper etching. Due to the high reflectivity of copper, the laser marking depth is generally ≤5um. After cleaning, the copper oxide is removed, the recognition is very low, and it cannot meet the alignment requirements of the downstream packaging process. Summary of the invention

[0004] Purpose of the invention: The purpose of the present invention is to address the deficiencies in the prior art and to provide an AMB product with a high recognition PR target and a preparation method thereof.

[0005] Technical solution: A method for preparing an AMB with high recognition PR target, comprising a solder layer, a copper layer and a ceramic layer (3), wherein the preparation steps are as follows: S1. Preparation of copper-clad ceramic substrate; Preparation of copper-clad ceramic substrate using active metal brazing process; S2. Preparation of PR target etching holes on copper surface; using chemical method, PR target etching holes on copper surface are prepared by one etching; S3. Removal of solder from PR target etching holes: using chemical method to make PR target etching holes on copper surface by secondary etching; removing solder from PR target etching holes; S4. Laser marking of ceramics in PR target etched holes; Use laser to laser mark ceramics in PR target etched holes; S5. Automatic optical inspection: Use AOI automatic optical inspection instrument to identify the target points of the cleaned AMB products.

[0006] A further improvement of the present invention is that the thickness of the copper layer is 0.5 mm, and the thickness of the ceramic layer (3) is 0.25 mm.

[0007] A further improvement of the present invention is that in step S2, the steps for making the copper surface PR target etching hole are: S21. Substrate cleaning: Before etching, the copper surface is thoroughly cleaned to remove oil, oxides and dust impurities to ensure that the pattern dry film can completely fit the copper surface; S22. Production of dry film graphics; when designing dry film graphics, the graphics of the etching holes should be accurately designed according to the position of the PR target, and there should be no position deviation; S23. Circuit filming: Use FST-50um dry film to process the circuit filming of the copper-clad ceramic substrate. During the filming process, there should be no bubbles, wrinkles, or dry film damage defects. S24. Line exposure; use a line film exposure machine to expose the pattern; S25. Etching once to make an etched hole; using a chemical method to remove the copper surface without dry film coverage on the horizontal line body, etching the copper surface shape; S26. Remove the dry film; use a 10% by mass sodium hydroxide solution to remove excess dry film patterns.

[0008] A further improvement of the present invention is that in step S21, a dilute sulfuric acid solution with a mass concentration of 10%, a sodium hydroxide solution with a mass concentration of 10% and high-pressure water are used to clean the copper surface of the substrate.

[0009] A further improvement of the present invention is that in step S23, the temperature when the copper-clad ceramic substrate is subjected to the circuit film lamination treatment is 110°C and the pressure is 5kg / cm².

[0010] A further improvement of the present invention is that in step S3, after removing the solder in the PR target etching hole, there is no solder residue and soldering over-etching.

[0011] A further improvement of the present invention is that in step S4, the PR target laser marking is performed on the ceramic surface in the etched hole, and a black ceramic molten layer is generated on the laser marked ceramic surface so that it will not be cleaned off in the post-process, thereby improving the recognition of the PR target by the application end.

[0012] An AMB product with a high-recognition PR target adopts an AMB preparation method with a high-recognition PR target, wherein the solder layer comprises a solder layer 1 and a solder layer 2, wherein the solder layer 1 is arranged on the top side of the ceramic layer, and the solder layer 2 is arranged on the bottom side of the ceramic layer, and the copper layer comprises a copper layer 1 and a copper layer 2, wherein the solder layer 1 is located between the copper layer 1 and the ceramic layer, and the solder layer 2 is located between the copper layer 2 and the ceramic layer.

[0013] Compared with the prior art, the AMB product with high recognition of PR targets and the preparation method thereof provided by the present invention achieve at least the following beneficial effects: The present invention utilizes copper etching and solder etching processes to remove the copper and solder layers corresponding to the original PR target, thereby realizing the transformation of the processed surface of the PR target from the original copper surface to the ceramic surface; utilizes a laser marking process to laser mark the ceramic surface to generate a black ceramic molten layer, which will not be removed after a cleaning process, thereby significantly increasing the recognition of the PR target; the PR target prepared by the present invention has a significant difference in longitudinal size compared with the existing PR target, and the marking depth is greatly increased, thereby further increasing the recognition of the PR target; the PR target prepared by the present invention is not affected by the copper thickness, ceramic type, and ceramic color differences of AMB products, and no new process is introduced, thereby having universal applicability. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 AMB product stacking and existing copper surface PR target schematic diagram; Figure 2 It is a schematic diagram of the AMB product stacking structure and the copper surface PR target of the present invention; Figure 3 This is a physical picture of the PR target on the existing copper surface of the AMB product after laser marking; Figure 4 This is a physical picture of the PR target on the existing copper surface of the AMB product after cleaning; Figure 5 This is a physical picture of the PR target of the AMB product of the present invention after laser marking; Figure 6 This is a physical picture of the PR target of the AMB product of the present invention after cleaning; Description of reference numerals: 1-copper layer one; 2-solder layer one; 3-ceramic layer; 4-solder layer two; 5-copper layer two; H1-original marking depth; H2-marking depth of the present invention. DETAILED DESCRIPTION

[0015] Various exemplary embodiments of the present invention are now described in detail. It should be noted that unless otherwise specifically stated, the relative arrangement of the components and steps, numerical expressions and numerical values ​​described in these embodiments do not limit the scope of the present invention. The following description of at least one exemplary embodiment is actually only illustrative and is not intended to be any limitation on the present invention and its application or use.

[0016] The techniques, methods and devices known to those of ordinary skill in the relevant art may not be discussed in detail, but where appropriate, the techniques, methods and devices should be considered as part of the specification. In all examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not as limiting. Therefore, other examples of the exemplary embodiments may have different values.

[0017] See also Figure 2 , Figure 5-6 , a method for preparing an AMB with high recognition PR target, comprising a solder layer, a copper layer and a ceramic layer (3), and the preparation steps are as follows: S1. Preparation of copper-clad ceramic substrate; Preparation of copper-clad ceramic substrate using active metal brazing process; S2. Preparation of PR target etching holes on copper surface; using chemical method, PR target etching holes on copper surface are prepared by one etching; S3. Removal of solder from PR target etching holes: using chemical method to make PR target etching holes on copper surface by secondary etching; removing solder from PR target etching holes; S4. Laser marking of ceramics in PR target etched holes; Use laser to laser mark ceramics in PR target etched holes; S5. Automatic optical inspection: Use AOI automatic optical inspection instrument to identify the target points of the cleaned AMB products.

[0018] The thickness of the copper layer is 0.5 mm, and the thickness of the ceramic layer 3 is 0.25 mm.

[0019] In step S2, the steps for making the copper surface PR target etching hole are as follows: S21. Substrate cleaning: Before etching, the copper surface is thoroughly cleaned to remove oil, oxides and dust impurities to ensure that the pattern dry film can completely fit the copper surface; S22. Production of dry film graphics; when designing dry film graphics, the graphics of the etching holes should be accurately designed according to the position of the PR target, and there should be no position deviation; S23. Circuit filming: Use FST-50um dry film to process the circuit filming of the copper-clad ceramic substrate. During the filming process, there should be no bubbles, wrinkles, or dry film damage defects. S24. Line exposure; use a line film exposure machine to expose the pattern; S25. Etching once to make an etched hole; using a chemical method to remove the copper surface without dry film coverage on the horizontal line body, etching the copper surface shape; S26. Remove the dry film; use a 10% by mass sodium hydroxide solution to remove excess dry film patterns.

[0020] In step S21, the copper surface of the substrate is cleaned by washing with water using a dilute sulfuric acid solution with a mass concentration of 10%, a sodium hydroxide solution with a mass concentration of 10%, and high-pressure water.

[0021] In step S23, the temperature during the circuit film lamination process on the copper-clad ceramic substrate is 110°C and the pressure is 5kg / cm².

[0022] In step S3, after removing the solder in the PR target etching hole, there is no solder residue and solder over-etching.

[0023] In step S4, the PR target laser marking is performed on the ceramic surface in the etched hole, and a black ceramic molten layer is generated on the laser-marked ceramic surface so that it will not be cleaned off in the post-process, thereby improving the recognition of the PR target by the application end.

[0024] An AMB product with a high-recognition PR target, adopting an AMB preparation method with a high-recognition PR target, the solder layer includes a solder layer 2 and a solder layer 4, the solder layer 2 is arranged on the top side of the ceramic layer 3, the solder layer 4 is arranged on the bottom side of the ceramic layer 3, the copper layer includes a copper layer 1 and a copper layer 5, the solder layer 2 is located between the copper layer 1 and the ceramic layer 3, and the solder layer 4 is located between the copper layer 5 and the ceramic layer 3.

[0025] The present invention utilizes copper etching and solder etching processes to remove the copper and solder layers corresponding to the original PR target, thereby realizing the transformation of the PR target processing surface from the original copper surface to the ceramic surface; utilizing the laser marking process, laser marking on the ceramic surface can generate a black ceramic molten layer, which will not be removed after cleaning, thereby significantly increasing the recognition of the PR target; the PR target prepared by the present invention has a significant difference in longitudinal dimensions compared with the existing PR target, and the marking depth is greatly increased, such as Figure 1 As shown, the original marking depth H1≤5um, such as Figure 2 As shown, the marking depth H2 of the present invention is the thickness of the copper layer 1 + the thickness of the solder layer 1 + the original marking depth, which increases the recognition of the PR target; the PR target prepared by the present invention is not affected by the copper thickness, ceramic type, and ceramic color differences of the AMB product, no new process is introduced, and it has universal applicability.

[0026] The specific embodiments described herein are merely examples of the spirit of the present invention. Those skilled in the art may make various modifications or additions to the specific embodiments described or replace them in similar ways, but they will not deviate from the spirit of the present invention or exceed the scope defined by the appended claims.

Claims

1. A method for preparing AMBs with high recognition of PR targets, characterized in that: The method comprises a solder layer, a copper layer and a ceramic layer (3), and the preparation steps are as follows: S1. Preparation of copper-clad ceramic substrate; Preparation of copper-clad ceramic substrate using active metal brazing process; S2. Preparation of PR target etching holes on copper surface; using chemical method, PR target etching holes on copper surface are prepared by one etching; S3. Removal of solder from PR target etching holes: using chemical method to make PR target etching holes on copper surface by secondary etching; removing solder from PR target etching holes; S4. Laser marking of ceramics in PR target etched holes; Use laser to laser mark ceramics in PR target etched holes; S5. Automatic optical inspection: Use AOI automatic optical inspection instrument to identify the target points of the cleaned AMB products.

2. The method for preparing a high-recognition PR target according to claim 1, characterized in that: The thickness of the copper layer is 0.5 mm, and the thickness of the ceramic layer (3) is 0.25 mm.

3. The method for preparing a high-recognition PR target according to claim 1, characterized in that: In step S2, the steps for making the copper surface PR target etching hole are as follows: S21. Substrate cleaning: Before etching, the copper surface is thoroughly cleaned to remove oil, oxides and dust impurities to ensure that the pattern dry film can completely fit the copper surface; S22. Production of dry film graphics; when designing dry film graphics, the graphics of the etching holes should be accurately designed according to the position of the PR target, and there should be no position deviation; S23. Circuit filming: Use FST-50um dry film to process the circuit filming of the copper-clad ceramic substrate. During the filming process, there should be no bubbles, wrinkles, or dry film damage defects. S24. Line exposure; Use a line film exposure machine to expose the graphics; S25. Etching a hole once; using a chemical method to remove the copper surface without dry film coverage on the horizontal line body, etching the copper surface shape; S26. Remove the dry film; use a 10% by mass sodium hydroxide solution to remove excess dry film patterns.

4. The method for preparing a high-recognition PR target according to claim 3, characterized in that: In the step S21, the copper surface of the substrate is cleaned by washing with a 10% by mass concentration dilute sulfuric acid solution, a 10% by mass concentration sodium hydroxide solution and high-pressure water.

5. The method for preparing a high-recognition PR target according to claim 3, characterized in that: In the step S23, the temperature when the copper-clad ceramic substrate is subjected to the circuit film lamination treatment is 110°C and the pressure is 5kg / cm².

6. The method for preparing an AMB with high recognition rate for PR target according to claim 1, characterized in that: In the step S3, after the solder in the PR target etching hole is removed, there is no solder residue and solder over-etching.

7. The method for preparing an AMB with high recognition rate for PR target according to claim 1, characterized in that: In step S4, the PR target laser marking is performed on the ceramic surface in the etched hole, and a black ceramic molten layer is generated on the laser-marked ceramic surface so that it will not be washed away in the post-process, thereby improving the recognition of the PR target by the application end.

8. An AMB product with high recognition PR target, characterized in that: A method for preparing an AMB with a high recognition PR target as described in claim 1 is adopted, wherein the solder layer comprises a solder layer 1 (2) and a solder layer 2 (4), wherein the solder layer 1 (2) is arranged on the top side of the ceramic layer (3), and the solder layer 2 (4) is arranged on the bottom side of the ceramic layer (3); the copper layer comprises a copper layer 1 (1) and a copper layer 2 (5), wherein the solder layer 1 (2) is located between the copper layer 1 (1) and the ceramic layer (3), and the solder layer 2 (4) is located between the copper layer 2 (5) and the ceramic layer (3).

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