A Solder Mask Printing Method for AMB Ceramic Substrate

Abstract

The present invention belongs to the technical field of solder mask processing for circuit boards, and specifically relates to a solder mask printing method for an AMB ceramic substrate, which includes the following steps: S1. Placing the board: Place the AMB ceramic substrate under the stencil; S2. Applying ink: Pour the solder mask ink onto the non-opening positions on the front surface of the silk screen, and scrape the ink from one side of the silk screen opening to the other side to fill the mesh holes of the silk screen opening with the ink; S3. Scraping the bottom: Scrape off the excess ink leaking to the back of the silk screen stencil; S4. Printing: Avoiding the ink pile on the silk screen stencil, transfer the ink in the mesh holes of the silk screen opening to the AMB ceramic substrate; wherein, in step S4, the height distance between the back surface of the silk screen stencil and the upper surface of the AMB ceramic substrate is 3-8 mm. The present invention realizes printing the solder mask ink on the copper surface, while not printing the solder mask ink on the ceramic, preventing the solder mask ink from overflowing to the side of the copper surface or even the ceramic insulation groove area during the printing process.

Description

Technical Field

[0001] The present invention relates to the field of patterning processing of AMB ceramic substrates, and more specifically, to a solder mask printing method for AMB ceramic substrates. Background Art

[0002] The ceramic copper clad laminate combines the excellent electrical conductivity of copper and the excellent insulation performance of ceramics, and is an important substrate material for packaging power devices in the field of power electronics. The active metal brazing (AMB) process used in the preparation of ceramic copper clad substrates is one of the important production processes for ceramic metallization, especially suitable for non-oxide ceramics AlN and Si3N4 commonly used in high-reliability fields. It brazes the ceramic plate and the metal copper foil together with an active filler metal, and the bonding reliability is significantly better than other metallization processes.

[0003] The solder mask process is to coat a layer of solder mask ink on the circuits and substrates that do not need to be soldered on the surface of the substrate, which plays the roles of solder mask insulation, oxidation prevention, and appearance beautification. Generally, it includes processes such as solder mask printing, baking and curing, and exposure and development. Solder mask printing is generally to apply the solder mask ink onto the substrate by screen printing. The specific screen printing method is to pour the solder mask ink on the non-opening position on the front surface of the screen mesh of the screen printing plate, and use a printing squeegee to scrape a large amount of accumulated solder mask ink from one side of the screen opening to the other side so that the solder mask ink penetrates through the mesh holes of the screen opening and is printed on the substrate. During printing, it is necessary to ensure that the screen mesh surface contacts the substrate surface. Usually, two printing squeegees are used to print alternately left and right. The screen printing process is mature and generally automated. In order to improve production efficiency, workers generally pour more ink on the screen printing plate, and each time the printing squeegee prints, all the accumulated ink on the plate is directly transferred to the surface of the substrate, which is convenient for realizing rapid printing. The screen printing equipment can also be applied to the solder mask printing of AMB ceramic substrates.

[0004] The copper thickness of traditional PCB boards is small, generally in the order of dozens of microns. The height difference between the ceramic surface and the copper surface is small, and the overall board surface approaches a planar structure, which is easy to make a solder mask structure for the entire surface. Therefore, a solder mask design for the entire board in a large area is usually adopted, and both the insulating grooves and the copper circuits are covered with solder mask ink, and only the functional copper window positions are exposed for uses such as chip mounting, soldering, and wire bonding.

[0005] When the same solder mask printing process for the entire board in a large area is extended to AMB ceramic substrates, due to the relatively large copper thickness of AMB ceramic substrates, usually above 0.1 mm, and a more three-dimensional structure, the height difference between the ceramic and copper surfaces is large, and the grooves are deep. During solder mask printing, it will bring a large difference in the thickness of the solder mask ink at the grooves and the solder mask ink on the copper surface, resulting in uneven curing of the solder mask ink and poor filling effect of the solder mask ink at the grooves. Therefore, for AMB ceramic substrates, generally only solder mask ink is printed on the copper, and no solder mask ink is printed on the ceramic.

[0006] According to this method of printing solder mask ink only on copper, during the solder mask printing process on AMB ceramic substrates, for AMB ceramic substrates with a copper thickness of more than 0.3mm, due to the large surface height difference between the ceramic and copper surfaces, when printing solder mask ink on the copper surface, the solder mask ink can be well controlled not to overflow to the copper side, or even overflow to the ceramic surface. However, for printed substrates with a copper thickness of 0.1-0.3mm, due to the small surface height difference between the ceramic and copper surfaces, when printing solder mask ink only on copper, it is very easy for the solder mask ink to overflow to the copper side or even the ceramic surface near the copper. However, it is difficult for the solder mask ink to fill the ceramic surface at the groove position, resulting in the difficulty in ensuring the printing uniformity and consistency of the solder mask ink at different positions on the AMB ceramic substrate surface, and even the solder mask ink may exceed the copper edge and warp up after curing (such as Figure 1 In this case, the lifted part of the cured solder mask ink is easily broken and fallen off by external force, which has serious consequences for the subsequent packaging process. Summary of the invention

[0007] The object of the present invention is to overcome the deficiencies of the above-mentioned prior art and provide a solder resist printing method for an AMB ceramic substrate. By adding ink laying and bottom scraping steps and controlling the height distance between the back of the silk screen and the upper surface of the AMB ceramic substrate, solder resist ink is printed on the copper surface, while solder resist ink is not printed on the ceramic, thereby preventing the solder resist ink from overflowing to the side of the copper surface or even the ceramic insulating groove area during the printing process, thereby preventing the solder resist ink from exceeding the copper edge and curling up and falling off after curing.

[0008] The above-mentioned object of the present invention is achieved by the following technical solutions:

[0009] A method for printing solder mask on an AMB ceramic substrate comprises the following steps:

[0010] S1. Place the board: place the AMB ceramic substrate under the stencil;

[0011] S2. Spreading ink: Pour solder mask ink on the non-opening position on the front surface of the screen, and scrape the ink from one side of the screen opening to the other side to fill the mesh opening of the screen with ink;

[0012] S3. Scrape the bottom: scrape off the excess ink that leaks to the back of the screen;

[0013] S4. Printing: Avoid the ink pile on the screen plate and transfer the ink in the screen opening mesh to the AMB ceramic substrate;

[0014] Wherein, the copper coating thickness of the AMB ceramic substrate in step S1 is 0.1-0.3 mm;

[0015] In step S4, the height distance between the back surface of the silk screen plate and the upper surface of the AMB ceramic substrate is 3-8 mm.

[0016] Since the solder resist ink is printed on the copper surface of the AMB ceramic substrate with a copper coating thickness of 0.1-0.3mm, but the solder resist ink is not printed on the groove ceramic surface, it is more likely that the solder resist ink will overflow onto the copper side or even the ceramic surface near the copper. Therefore, the method of the present invention is particularly suitable for solder resist printing on the AMB ceramic substrate with a copper coating thickness of 0.1-0.3mm.

[0017] The present invention adds the ink spreading action of step S2 and the bottom scraping action of step S3, so that the solder resist ink to be transferred to the copper surface of the AMB ceramic substrate is almost all in the opening mesh of the screen, and there is almost no excess ink on the upper surface and the back surface of the opening mesh of the screen, so that the solder resist ink in the opening mesh of the screen can be transferred to the copper surface of the AMB ceramic substrate underneath during printing in step S4, and the amount of ink leaked through the screen to the copper surface of the AMB ceramic substrate can be strictly controlled to avoid excessively thick solder resist ink overflowing from the edge of the copper surface to the side of the copper surface, and to avoid the solder resist ink attached to the back of the screen from being squeezed to the side of the copper surface when it contacts the substrate.

[0018] The present invention also increases the distance between the silk screen mesh plate and the upper surface of the AMB ceramic substrate so that when printing in step S4, the silk screen mesh surface forms a larger deformation curvature, thereby ensuring that the solder resist ink that has been missed on the copper surface is completely separated from the silk screen mesh surface near the position where the silk screen mesh surface and the AMB ceramic substrate surface are in line contact, thereby preventing the solder resist ink on the copper surface from sticking to the silk screen over a large area, completely separating the local silk screen from the copper surface of the AMB ceramic substrate, and not destroying the continuous printing state, thereby preventing the stuck position from damaging the copper surface where the solder resist ink has been printed when the silk screen is lifted and forcibly separated.

[0019] Therefore, the solder resist printing method of the AMB ceramic substrate can ensure that the ink at the groove position on the AMB ceramic substrate is still in the mesh of the silk screen, that is, the solder resist ink is only printed on the copper surface of the AMB ceramic substrate, and there is no solder resist ink on the ceramic surface of the groove of the AMB ceramic substrate, thereby avoiding the problem that the ceramic groove is deep and difficult to fill with ink, and further preventing the solder resist ink from unevenly overflowing to the ceramic surface at the groove position, resulting in poor consistency of solder resist at different positions and uneven curing.

[0020] In summary, when the solder resist ink is printed on a large-area entire page, the solder resist ink is not likely to overflow onto the copper side or even the ceramic surface near the copper. The printing uniformity and consistency of the solder resist ink at different positions on the board surface are excellent, and the solder resist ink will not exceed the copper edge and warp up after curing, thereby preventing the warped part of the solder resist ink from being easily broken and falling off by external force, causing adverse effects on subsequent packaging.

[0021] In practical applications, when the AMB ceramic substrate is adsorbed onto the vacuum adsorption platform of the printing table in step S1 of placing the plate, the height distance between the back surface of the screen printing stencil and the upper surface of the AMB ceramic substrate can be controlled to be H0. Subsequently, in step S3 of scraping the bottom, in order to facilitate operation, the screen printing stencil can be appropriately lifted. When the screen printing stencil is lowered again in step S4, the printing machine and the printing table can be used to control the height distance between the back surface of the screen printing stencil and the upper surface of the AMB ceramic substrate to still be the above-mentioned distance H0.

[0022] In practical applications, after the solder mask printing is completed, it further includes preliminarily baking and curing the solder mask ink printed on the AMB ceramic substrate to make it reach the curing degree requirement for exposure and development.

[0023] In practical applications, after baking and curing, it further includes exposing and developing the solder mask ink on the AMB ceramic substrate according to the required solder mask pattern to obtain an AMB ceramic substrate with the required solder mask ink pattern.

[0024] In step S4, the height distance between the back surface of the screen printing stencil and the upper surface of the AMB ceramic substrate can be 3 mm, 4 mm, 5 mm, 6 mm, 7 mm, 8 mm. More preferably, it is 4 - 6 mm.

[0025] The copper cladding thickness of the AMB ceramic substrate can be 0.1 mm, 0.15 mm, 0.2 mm, 0.25 mm, 0.3 mm.

[0026] Preferably, the solder mask ink is composed of a main agent, a curing agent, and a thinner. The mass addition amount of the thinner is 0.5 wt% - 2 wt% of the sum of the main agent and the curing agent.

[0027] The mass addition amounts of the thinner are 0.5 wt%, 0.7 wt%, 1 wt%, 1.1 wt%, 1.3 wt%, 1.5 wt%, 1.7 wt%, 2 wt% of the sum of the main agent and the curing agent.

[0028] The dosage of the diluent is determined according to the state of the ink on the stencil during actual printing.

[0029] The mass ratio of the main agent to the curing agent can adopt the recommended commercial ratio, for example, it can be 3:1.

[0030] Preferably, after step S2 or step S3, it further includes using a spatula to push the ink back to the starting position.

[0031] The purpose of using a spatula to push the ink back to the starting position is to facilitate the next round of ink spreading and printing.

[0032] More preferably, after step S3, use a spatula to push the ink back to the starting position.

[0033] Preferably, the shoveling direction of the scraper forms an angle of 90-150 degrees with the scraper plane.

[0034] This angle setting is to prevent too much ink from being pressed into the stencil by the scraper, resulting in excessive ink leakage through the back of the stencil or even dripping from the back of the stencil.

[0035] The angle between the shoveling direction of the scraper and the scraper plane can be 90 degrees, 100 degrees, 110 degrees, 120 degrees, 130 degrees, 140 degrees, 150 degrees.

[0036] Preferably, in step S2, a printing squeegee is used to scrape the ink from one side of the silk screen opening to the other side to fill the mesh holes of the silk screen opening, and the printing angle of the printing squeegee is 60-85 degrees.

[0037] In step S2, when the printing angle is slightly larger, it can not only spread the solder resist ink into the mesh holes of the silk screen, but also prevent too much ink from leaking through the silk screen stencil to the back of the silk screen.

[0038] In step S2, the printing angle of the printing squeegee can be 60 degrees, 65 degrees, 70 degrees, 75 degrees, 80 degrees, 85 degrees.

[0039] In step S2, by controlling the printing pressure to be slightly smaller, the silk screen will not contact the AMB ceramic substrate when the printing squeegee scrapes and spreads the ink.

[0040] Preferably, in step S4, a printing squeegee is used to print and transfer the ink in the mesh holes of the silk screen opening to the AMB ceramic substrate, and the printing angle of the printing squeegee is 45-70 degrees.

[0041] In step S4, by controlling the printing angle of the printing squeegee and combining with a larger printing pressure, it is beneficial to transfer all the ink in the silk screen mesh holes to the copper surface of the AMB ceramic substrate.

[0042] In step S4, the printing angle of the printing squeegee is 45 degrees, 50 degrees, 55 degrees, 60 degrees, 65 degrees, 70 degrees.

[0043] Preferably, in step S3, after scraping off the excess ink leaking to the back of the silk screen stencil, it is recovered to the front of the silk screen. This is beneficial to prevent ink waste.

[0044] In step S3, a printing squeegee can be used to scrape off the excess ink leaking to the back of the silk screen stencil.

[0045] Preferably, the material of the silk screen stencil can be nylon or stainless steel.

[0046] Since the present invention is for large-area full-panel printing, a large screen distance needs to be coordinated so that the screen surface deforms greatly during printing, presenting a large screen surface drop. In this way, it shows a significant line contact with the surface of the AMB ceramic substrate, avoiding the ink on the copper from being detached from the screen and sticking, which may damage the printed solder mask surface.

[0047] Nylon material has more excellent elasticity and is more suitable for the method of the present invention.

[0048] In practical applications, the mesh number of the screen printing stencil in step S1 is 80 - 200 meshes.

[0049] The method of the present invention is particularly suitable for large-area full-panel printing.

[0050] In the art, a length of 180 - 190 mm and a width of 130 - 140 mm for the opening of the screen printing stencil are generally referred to as large area.

[0051] In practical applications, the opening size of the screen printing stencil is the same as the outer shape size of the AMB ceramic substrate.

[0052] Preferably, in steps S2, S3, and S4, the printing squeegee is a polyurethane squeegee with a thickness of 5 - 10 mm.

[0053] Preferably, in step S2, the spatula is a thin stainless steel sheet with a thickness of 0.05 - 0.2 mm.

[0054] Preferably, the solder mask printing method for the AMB ceramic substrate includes the following steps:

[0055] S1. Placing the board: Adsorb the AMB ceramic substrate onto the vacuum adsorption platform of the printing table and adjust the height position of the screen.

[0056] S2. Ink spreading: Pour the solder mask ink onto the non-opening position on the front side of the screen, and use the printing squeegee to scrape the ink from one side of the screen opening to the other side to fill the mesh holes of the screen opening.

[0057] S3. Bottom scraping: Lift the screen printing stencil, use the printing squeegee to scrape off the excess ink leaking to the back of the screen printing stencil and recover it to the front of the screen, and then use the spatula to push and shovel the ink back to the starting position.

[0058] S4. Printing: Lower the screen printing stencil, and use the printing squeegee to avoid the ink pile on the screen printing stencil, and transfer the ink in the mesh holes of the screen opening to the AMB ceramic substrate under the screen printing stencil.

[0059] The present invention also protects the AMB ceramic substrate processed by the solder mask printing method for the AMB ceramic substrate described in any one of the above.

[0060] The present invention also protects the application of the above-mentioned AMB ceramic substrate in the packaging of power devices in the field of power electronics.

[0061] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0062] The present invention discloses a solder mask printing method for an AMB ceramic substrate. By adding an ink spreading and scraping bottom process and controlling the height distance between the back of the screen printing stencil and the upper surface of the AMB ceramic substrate, solder mask ink is printed on the copper surface, while no solder mask ink is printed on the ceramic, preventing the solder mask ink from overflowing to the side of the copper surface or even the ceramic insulating groove area during the printing process, thereby preventing the solder mask ink from exceeding the copper edge and warping and falling off after curing. At the same time, it avoids the problems of insufficient filling of the solder mask ink in the insulating groove area and large differences in the thickness of the solder mask ink compared to the copper surface area, resulting in uneven curing when the solder mask process of a conventional PCB circuit board is used for the AMB ceramic substrate.

[0063] The operation of the present invention is simple, easy to automate, and applicable to mass production. BRIEF DESCRIPTION OF THE DRAWINGS

[0064] Figure 1 It is a picture of the edge warping after the solder mask ink overflows beyond the copper edge of the AMB ceramic substrate and solidifies on the side.

[0065] Figure 2 It is a schematic diagram of the operation process of the solder mask printing method for the AMB ceramic substrate in Example 1.

[0066] Figure 3 It is the implementation effect diagram of Examples 1 - 5.

[0067] Figure 4 It is the implementation effect diagram of Comparative Example 1.

[0068] Figure 5 It is the implementation effect diagram of Comparative Example 2.

[0069] Figure 6 and Figure 7 It is the implementation effect diagram of Comparative Example 3. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0070] In order to more clearly and completely describe the technical solution of the present invention, the following further details the present invention through specific embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention, and various changes can be made within the scope defined by the claims of the present invention.

[0071] Example 1

[0072] As Figure 2 shown, a solder mask printing method for an AMB ceramic substrate includes the following steps:

[0073] S1. Place the board and adjust the machine: Adsorb the AMB ceramic substrate with an outer dimension of 190x140 mm and a copper cladding thickness of 0.2 mm onto the vacuum adsorption platform of the printing table. Use a nylon screen with an opening of 190x140 mm and 100 meshes to make the height distance between the back of the screen printing plate and the upper surface of the AMB ceramic substrate 5 mm;

[0074] S2. Apply the ink: Pour the solder resist ink with a mass ratio of main agent to curing agent of 3:1 and 1 wt% thinner added onto the non-opening position on the front surface of the screen. Use a polyurethane printing squeegee to control the printing angle at about 70° and combine with a small printing pressure to scrape the ink from one side of the screen opening to the other side to fill the mesh holes of the screen opening. Then use a 0.1 mm thick thin steel sheet spatula to push and shovel the ink piled up on the screen surface back to the printing starting position at a shoveling angle of about 120°;

[0075] S3. Scrape the bottom: Lift the screen printing plate and use a printing squeegee to scrape off the excess ink leaking to the back of the screen printing plate and recycle it to the front of the screen;

[0076] S4. Print: Lower the screen printing plate to make the height distance between the back of the screen printing plate and the upper surface of the AMB ceramic substrate 5 mm. Use a printing squeegee to avoid the ink pile on the screen printing plate and only transfer the ink in the mesh holes of the screen opening to the AMB ceramic substrate under the screen printing plate; the printing angle is 60°.

[0077] S5. Bake and cure: Do a preliminary bake and cure on the solder resist ink printed on the AMB ceramic substrate to make it reach the curing degree requirement for exposure and development;

[0078] S6. Expose and develop: Expose and develop the solder resist ink on the AMB ceramic substrate according to the required solder resist pattern to obtain the AMB ceramic substrate with the required solder resist ink pattern.

[0079] Example 2

[0080] A method for solder resist printing of an AMB ceramic substrate is basically the same as that in Example 1, except for steps S2 and S3:

[0081] S2. Apply the ink: Pour the solder resist ink with a mass ratio of main agent to curing agent of 3:1 and 1 wt% thinner added onto the non-opening position on the front surface of the screen. Use a polyurethane printing squeegee to control the printing angle at about 70° and combine with a small printing pressure to scrape the ink from one side of the screen opening to the other side to fill the mesh holes of the screen opening;

[0082] S3. Scraping the bottom: Lift the silk screen stencil, use a printing squeegee to scrape off the excess ink leaked to the back of the silk screen stencil and recycle it to the front of the silk screen, and then use a thin steel blade spatula with a thickness of 0.1 mm to push and shovel the ink accumulated on the stencil surface back to the printing starting position at a shoveling angle of about 120°.

[0083] The rest is the same as in Embodiment 1 and will not be elaborated here.

[0084] Embodiment 3

[0085] A solder mask printing method for an AMB ceramic substrate is basically the same as that in Embodiment 1, except that: the stencil material is stainless steel.

[0086] Embodiment 4

[0087] A solder mask printing method for an AMB ceramic substrate is basically the same as that in Embodiment 1, except that:

[0088] In step S1, the copper cladding thickness of the AMB ceramic substrate is 0.1 mm.

[0089] In step S2, the angle between the shoveling direction of the spatula and the spatula plane is 90 degrees.

[0090] In step S2, the printing angle of the printing squeegee is 60 degrees.

[0091] In step S4, the height distance between the back of the silk screen stencil and the upper surface of the AMB ceramic substrate is 3 mm.

[0092] In step S4, the printing angle of the printing squeegee is 45 degrees.

[0093] Embodiment 5

[0094] A solder mask printing method for an AMB ceramic substrate is basically the same as that in Embodiment 1, except that:

[0095] In step S1, the copper cladding thickness of the AMB ceramic substrate is 0.3 mm.

[0096] In step S2, the angle between the shoveling direction of the spatula and the spatula plane is 150 degrees.

[0097] In step S2, the printing angle of the printing squeegee is 85 degrees.

[0098] In step S4, the height distance between the back of the silk screen stencil and the upper surface of the AMB ceramic substrate is 8 mm.

[0099] In step S4, the printing angle of the printing squeegee is 70 degrees.

[0100] Comparative Example 1

[0101] A solder mask printing method for an AMB ceramic substrate is basically the same as that of Example 1, except that: in step S4, the height distance between the back surface of the screen printing stencil and the upper surface of the AMB ceramic substrate is 2 mm.

[0102] Comparative Example 2

[0103] A solder mask printing method for an AMB ceramic substrate is basically the same as that of Example 1, except that: the scraping bottom action of step S3 is not performed.

[0104] Comparative Example 3

[0105] A solder mask printing method for an AMB ceramic substrate is carried out according to the conventional printing operation mode. The difference from Example 1 is that: in S4, the height distance between the back surface of the screen printing stencil and the upper surface of the AMB ceramic substrate is 2 mm, the ink spreading and scraping bottom actions of steps S2 and S3 are not performed, and the solder mask ink piled at the starting position of the screen printing surface is directly scraped by a printing squeegee to print the ink onto the AMB ceramic substrate.

[0106] Test results

[0107] The implementation effects of Examples 1 to 5 are as Figure 3 shown. The solder mask ink is only printed on the copper surface and not printed on or overflowed to the ceramic surface on the copper side or in the groove position.

[0108] The implementation effect of Comparative Example 1 is as Figure 4 shown. As shown at the arrow position, the solder mask ink overflows to the copper side.

[0109] The implementation effect of Comparative Example 2 is as Figure 5 shown. A large area of the solder mask ink is severely unevenly missed printed on the ceramic surface on the copper side and in the groove position.

[0110] The implementation effect of Comparative Example 3 is as Figure 6 and Figure 7 shown. The solder mask ink overflows to the copper side over the entire board surface, and in some local positions, the ink is missed printed on the ceramic surface in the groove position.

[0111] Obviously, the above-mentioned embodiments of the present invention are only examples for clearly illustrating the present invention, and are not intended to limit the implementation manners of the present invention. For those of ordinary skill in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the implementation manners here. Any modifications, equivalent replacements, and improvements made within the spirit and principles of the present invention shall be included within the protection scope of the claims of the present invention.

Claims

1. A solder mask printing method for an AMB ceramic substrate, characterized in that: The steps include: S1. Place the board: place the AMB ceramic substrate under the stencil; S2. Spreading ink: Pour solder mask ink on the non-opening position on the front surface of the screen, and scrape the ink from one side of the screen opening to the other side to fill the mesh opening of the screen with ink; S3. Scrape the bottom: scrape off the excess ink that leaks to the back of the screen; S4. Printing: Avoid the ink pile on the screen plate, and transfer the ink printing in the screen opening mesh to the AMB ceramic substrate; print the solder mask ink on the copper surface, and do not print the solder mask ink on the ceramic; Wherein, the copper coating thickness of the AMB ceramic substrate in step S1 is 0.1-0.3 mm; In step S4, the height distance between the back surface of the silk screen plate and the upper surface of the AMB ceramic substrate is 4-8 mm.

2. The solder resist printing method for the AMB ceramic substrate according to claim 1, characterized in that: The solder resist ink is composed of a main agent, a curing agent and a degreased oil solution, and the added amount of the degreased oil solution is 0.5wt%-2wt% of the sum of the main agent and the curing agent.

3. The solder resist printing method for the AMB ceramic substrate according to claim 1, characterized in that: After step S2 or step S3, the method further includes using a scraper to push the ink back to the starting position.

4. The solder resist printing method for the AMB ceramic substrate according to claim 3, characterized in that: The angle between the scraping direction of the scraper and the scraper plane is 90-150 degrees.

5. The solder mask printing method for the AMB ceramic substrate according to claim 1, characterized in that: In step S2, a printing scraper is used to scrape the ink from one side of the screen opening to the other side so that the ink fills the mesh holes of the screen opening. The printing angle of the printing scraper is 60-85 degrees.

6. The solder resist printing method for the AMB ceramic substrate according to claim 1, characterized in that: In step S4, the ink in the opening mesh of the screen is transferred to the AMB ceramic substrate by printing with a printing scraper, and the printing angle of the printing scraper is 45-70 degrees.

7. The solder resist printing method for the AMB ceramic substrate according to claim 1, characterized in that: In step S3, the excess ink leaking onto the back of the screen plate is scraped off and recovered onto the front of the screen.

8. The solder resist printing method for the AMB ceramic substrate according to claim 1, characterized in that: The wire mesh plate in step S1 is a nylon wire mesh.

9. An AMB ceramic substrate obtained by the solder resist printing method for an AMB ceramic substrate according to any one of claims 1 to 8.

10. Application of the AMB ceramic substrate according to claim 9 in power device packaging in the field of power electronics.

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