A printing method for multi-layer co-fired ceramic package inner cavity sidewall metallization pattern

Abstract

The present application relates to the technical fields of multilayer co-fired ceramic packaging substrate and shell, and discloses a multilayer co-fired ceramic packaging inner cavity side wall metallization pattern printing method, which comprises the following steps: completing green ceramic surface pattern and via metallization according to a multilayer ceramic production process; sequentially laminating adjacent layers with the same cavity pattern into a laminated body; coating the upper and lower surfaces of the laminated body, and completing the first cavity gap cutting; filling the metallization paste into the cavity gap by using a screen printing process; removing the excess paste in the cavity gap through a paste extraction table; drying the paste; completing the second cavity pattern cutting; and sequentially laminating each laminated body into a complete laminated body after film tearing. The method is used for printing the metallization pattern of the inner cavity side wall of the multilayer co-fired ceramic packaging, and the side wall metallization area accounts for more than 90%, which solves the problem of high-frequency signal crosstalk, and has uniform metallization thickness, good appearance quality and high production efficiency.

Description

Technical Field

[0001] This invention relates to the field of multilayer co-fired ceramic packaging substrate and shell technology, specifically to a method for printing metallized patterns on the inner cavity sidewalls of a multilayer co-fired ceramic package. Background Technology

[0002] Multilayer co-fired ceramics, including low-temperature multilayer co-fired ceramics (LTCC) and high-temperature multilayer co-fired ceramics (HTCC), are mainly used to fabricate single-chip or multi-chip ceramic packaging substrates and shells to meet requirements such as mechanical protection, electrical interconnection, hermetically sealed packaging, functional integration, and reliability. To meet the needs of different functional chips operating normally, without interference, and for integrated packaging, the chips are mounted separately on the bottom of multilayer co-fired ceramic cavities of different sizes and depths. Metallization of the cavity sidewalls achieves isolation between low-frequency and high-frequency circuits, and between digital and analog signals. Since the cavity sidewalls are located on the inner surface of the ceramic package, conventional side printing cannot be used; furthermore, manual adhesive application suffers from uneven metallization thickness, poor appearance quality, and low production efficiency.

[0003] Currently, the method of mounting through holes on the edge of the cavity is often used instead. However, since the center-to-center spacing of the through holes needs to be more than twice the diameter of the through holes, the metallized pattern coverage area of ​​the inner cavity sidewall is less than half. This poses a risk of leakage of high-frequency electromagnetic waves, making it difficult to solve the problem of signal crosstalk between high-frequency chips in adjacent cavities.

[0004] Based on this, a method for printing metallized patterns on the inner cavity sidewalls of multilayer co-fired ceramic packaging is proposed. Summary of the Invention

[0005] Therefore, the purpose of this invention is to propose a method for printing metallized patterns on the inner cavity sidewalls of multilayer co-fired ceramic packaging, which improves the metallized area ratio and production efficiency while ensuring the printing quality of the inner cavity sidewalls.

[0006] To achieve the above objectives, the following technical solution is adopted:

[0007] A method for printing metallization patterns on the inner cavity sidewall of a multilayer co-fired ceramic package includes the following steps:

[0008] S100: Using green ceramic sheets and metallization paste, the surface patterns and through holes of each layer of green ceramic sheet are completed according to the multi-layer ceramic production process;

[0009] S200: Group the green ceramic pieces according to the cavity pattern. Adjacent green ceramic pieces with the same cavity pattern are grouped together. Each group of green ceramic pieces is stacked and pressed together in order of layer number to form a stacked body.

[0010] S300: Cover the upper and lower surfaces of the laminated parts formed in step S200 with an isolation film, and complete the first cavity gap cutting according to the cavity positioning marks on the surface of the laminated parts.

[0011] S400: The metallization paste is filled into the gaps of the stacked split cavities using a screen printing process.

[0012] S500: The excess metallized slurry in the gaps of the multilayered split cavity is quickly removed by the slurry extraction platform;

[0013] S600: Dry the metallization slurry on the sidewalls of the stacked split cavity;

[0014] S700: Complete the second cavity graphic cutting according to the cavity positioning marks on the surface of the stacked split body;

[0015] S800: Remove the release film from the upper and lower surfaces of the laminated components, stack the laminated components in order of layer number, and press them together into a complete laminated body.

[0016] Preferably, the multi-layer ceramic production process includes the following steps:

[0017] S101: Perforated green ceramic tile;

[0018] S102: Metallization slurry for filling raw ceramic tiles;

[0019] S103: Metallization paste for printing raw ceramic tiles.

[0020] Preferably, the layer numbering order is based on the stacking of multiple co-fired ceramics, with the raw ceramic pieces arranged from bottom to top as layer 1, layer 2, ..., and so on, with the topmost layer being layer n, where n ≥ 2.

[0021] Preferably, the isolation film on the surface of the stacked components is used to prevent contamination of the metallized patterns on the surface of the green ceramic, and is made of a polyimide material that is adhesive and resistant to high temperatures.

[0022] Preferably, the first cavity slot cutting is performed using laser cutting to process each sidewall of the cavity into a slot channel with a certain width, the sidewalls are vertical, and the slot width is 0.3mm to 3mm.

[0023] Preferably, the screen printing process includes using a screen printing machine and a matching printing screen.

[0024] Preferably, the slurry extraction platform includes a support plate, a positioning pin, a slurry extraction chamber, a baffle, an air intake pipe, and an air intake fan. The support plate is placed on the upper part of the slurry extraction chamber by the positioning pin. The upper part of the slurry extraction chamber has an open structure. The bottom of the slurry extraction chamber is connected to the air intake pipe, which is connected to the air intake fan. The baffle is installed in the slurry extraction chamber by the support column and is located directly above the air intake pipe. The opening pattern of the support plate is consistent with the gap pattern of the laminated split cavity.

[0025] Preferably, in step S600, the drying temperature is between 50°C and 150°C, and the drying time is between 5 min and 30 min.

[0026] Preferably, the second cavity pattern cutting involves connecting the various cavity gaps that have undergone cavity wall metallization to form a closed cavity pattern.

[0027] The beneficial effects of this invention are:

[0028] (1) This method uses a two-step cavity cutting scheme. The first step is to cut the cavity gap. After the sidewall of the cavity gap is metallized, the second cavity pattern is cut to interconnect the metallized sidewalls to form a closed cavity. The metallized area of ​​the cavity sidewall reaches more than 90%, which can achieve good electromagnetic shielding and solve the problem of signal crosstalk between high-frequency chips in adjacent cavities.

[0029] (2) The cavity is first laser-cut into a multilayer structure, and then the sidewall of the cavity is metallized and printed. The vertical cavity wall ensures the uniformity of the thickness of the sidewall metal layer after printing and slurry extraction.

[0030] (3) Adhere the isolation film to the upper and lower surfaces of the laminated body. This helps to prevent the slurry from flowing and splashing during the side wall printing and slurry extraction process, thus contaminating the surface of the raw ceramic and ensuring the appearance quality of the metallized graphic printing on the side wall of the cavity.

[0031] (4) Using screen printing technology to achieve metallization of the inner cavity sidewalls can ensure batch consistency of the metallization pattern printing of the cavity sidewalls and improve production efficiency. Attached Figure Description

[0032] The accompanying drawings, which form part of this application, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an undue limitation of the invention. In the drawings:

[0033] Figure 1 This is a schematic diagram of the first cavity gap cutting in the stacked and split structure of this invention;

[0034] Figure 2 This is a schematic diagram of the pumping platform in this invention;

[0035] Figure 3 This is a schematic diagram of the second cavity pattern cutting after the sidewall of the stacked split cavity in this invention has been metallized;

[0036] Figure 4 This is a schematic diagram of the complete stacked body in this invention.

[0037] Reference numerals: 1. Support plate; 2. Positioning pin; 3. Slurry extraction chamber; 4. Baffle; 5. Suction pipe; 6. Suction fan. Detailed Implementation

[0038] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0039] To enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present application, and not all embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative effort should fall within the scope of protection of the present application.

[0040] The following is in conjunction with the appendix Figure 1-4 The present invention will be described in further detail below.

[0041] A method for printing metallization patterns on the inner cavity sidewall of a multilayer co-fired ceramic package includes the following steps:

[0042] S100: Using green ceramic sheets and metallization paste, the surface patterns and through holes of each layer of green ceramic sheet are completed according to the multi-layer ceramic production process;

[0043] The multi-layer ceramic manufacturing process includes the following steps:

[0044] S101: Perforated green ceramic tile;

[0045] S102: Metallization slurry for filling raw ceramic tiles;

[0046] S103: Metallization paste for printing on raw ceramic tiles;

[0047] S200: Group the green ceramic pieces according to the cavity pattern. Adjacent green ceramic pieces with the same cavity pattern are grouped together. Each group of green ceramic pieces is stacked and pressed together in order of layer number to form a stacked body. The green ceramic pieces are arranged from bottom to top as layer 1, layer 2, ..., and so on, with the top layer being layer n, where n≥2.

[0048] S300: such as Figure 1 As shown, the upper and lower surfaces of the above-mentioned stacked parts are covered with a release film, and the first cavity gap cutting is completed according to the cavity positioning marks on the surface of the stacked parts.

[0049] The isolation membrane on the surface of the stacked parts is used to prevent contamination of the metallized pattern on the surface of the green ceramic. It is made of polyimide material with certain adhesion and high temperature resistance. The first cavity gap cutting is carried out by laser cutting to process each side wall of the cavity into a gap channel with a certain width. The side walls are required to be vertical and the gap width is 0.3mm to 3mm.

[0050] S400: The metallization paste is filled into the gaps of the stacked split cavities using a screen printing process.

[0051] The screen printing process includes using a screen printing machine and a matching printing screen. The screen has a mesh count of 325, a film thickness of 15µm, and a screen printing accuracy of ±25µm; or a screen has a mesh count of 200, a film thickness of 25µm, and a screen printing accuracy of ±25µm.

[0052] S500: The excess metallized slurry in the gaps of the above-mentioned stacked split cavities is quickly removed by the slurry extraction platform.

[0053] like Figure 2 As shown, the slurry extraction platform includes a support plate 1, a positioning pin 2, a slurry extraction chamber 3, a baffle 4, an air intake pipe 5, and an air intake fan 6. The support plate 1 is placed on the upper part of the slurry extraction chamber 3 via the positioning pin 2. The upper part of the slurry extraction chamber 3 has an open structure, and the bottom of the slurry extraction chamber 3 is connected to the air intake pipe 5, which is connected to the air intake fan 6. The baffle 4 is installed in the slurry extraction chamber 3 via a support column and is located directly above the air intake pipe 5. The opening pattern of the support plate 1 is consistent with the gap pattern of the laminated split cavity. First, the support plate 1 is placed on the slurry extraction platform via the positioning pin 2. Then, the laminated split cavity filled with slurry is placed on the support plate 1, with the upper and lower cavity patterns consistent. The air intake fan 6 is turned on, and the excess metallized slurry in the gap of the laminated split cavity is brought to the slurry extraction chamber 3 by the air intake. A baffle 4 is set at the bottom of the slurry extraction chamber 3 to prevent the metallized slurry from entering the air intake pipe 5 and causing blockage. The slurry extraction time is 1 minute to 3 minutes.

[0054] S600: Dry the metallized slurry on the side wall of the above-mentioned multilayered cavity, with a drying temperature between 50℃ and 150℃ and a drying time between 5min and 30min.

[0055] S700: such as Figure 3 As shown, the second cavity pattern cutting is completed according to the cavity positioning marks on the surface of the stacked parts; the second cavity pattern cutting is to connect the cavity gaps that have been metallized through the cavity walls to form a closed cavity pattern.

[0056] S800: such as Figure 4 As shown, the isolation films on the upper and lower surfaces of the above-mentioned stacked components are removed, and the stacked components are stacked in order of layer number and pressed into a complete stacked body. Example 1

[0057] A method for printing metallized patterns on the inner cavity sidewall of a multilayer co-fired ceramic package, the method comprising the following steps:

[0058] S100: Using green ceramic sheets and metallization paste, the surface patterns and through holes of each layer of green ceramic sheet are completed according to the multi-layer ceramic production process;

[0059] S200: Group the green ceramic sheets of each layer according to the cavity pattern. Adjacent green ceramic sheets with the same cavity pattern are grouped together. Each group of green ceramic sheets is stacked and pressed together in order of layer number to form a stacked body. The stacked body has a total of 3 layers, and the thickness of each green ceramic sheet is 130µm±3µm.

[0060] S300: such as Figure 1 As shown, the upper and lower surfaces of the above-mentioned stacked parts are covered with an isolation film. According to the cavity positioning marks on the surface of the stacked parts, the first cavity gap cutting is completed, and the cavity gap width is 400µm±50µm.

[0061] S400: Produce a matching printing screen with a mesh count of 325, a film thickness of 15µm, and a printing screen accuracy of ±25µm. Transfer the above-mentioned laminated split body that has undergone the first cavity opening to the screen printing machine and fill the gaps in the cavity of the laminated split body with metallization paste.

[0062] S500: The excess metallized slurry in the gaps of the above-mentioned stacked split cavities is quickly removed by the slurry pumping platform, and the pumping time is 1 minute.

[0063] S600: Remove the above-mentioned stacked parts from the pumping platform and place them in the drying oven to dry the metallization slurry on the side wall of the cavity. The drying temperature is 70℃ and the drying time is 15min.

[0064] S700: such as Figure 3 As shown, the second cavity pattern cutting is completed according to the cavity positioning marks on the surface of the stacked parts; the second cavity pattern cutting is to connect the cavity gaps that have been metallized through the cavity walls to form a closed cavity pattern.

[0065] S800: such as Figure 4 As shown, the isolation films on the upper and lower surfaces of the above-mentioned stacked components are removed, and the stacked components are stacked in order of layer number and pressed into a complete stacked body. Example 2

[0066] A method for printing metallized patterns on the inner cavity sidewall of a multilayer co-fired ceramic package, the method comprising the following steps:

[0067] S100: Using green ceramic sheets and metallization paste, the surface patterns and through holes of each layer of green ceramic sheet are completed according to the multi-layer ceramic production process;

[0068] S200: Group the green ceramic sheets according to the cavity pattern. Adjacent green ceramic sheets with the same cavity pattern are grouped together. Each group of green ceramic sheets is stacked and pressed together in order of layer number to form a stacked body. The stacked body has a total of 5 layers, and the thickness of each green ceramic sheet is 330µm±5µm.

[0069] S300: such as Figure 1 As shown, the upper and lower surfaces of the above-mentioned stacked parts are covered with an isolation film. According to the cavity positioning marks on the surface of the stacked parts, the first cavity gap cutting is completed, and the cavity gap width is 2mm±50µm.

[0070] S400: Produce a matching printing screen with a mesh count of 200, a film thickness of 25µm, and a printing screen accuracy of ±25µm. Transfer the above-mentioned laminated split body that has undergone the first cavity opening to the screen printing machine and fill the gaps in the cavity of the laminated split body with metallization paste.

[0071] S500: The excess metallized slurry in the gaps of the above-mentioned stacked split cavities is quickly removed by the slurry pumping platform, and the pumping time is 3 minutes.

[0072] S600: Remove the above-mentioned stacked parts from the pumping platform and place them in the drying oven to dry the metallization slurry on the side wall of the cavity. The drying temperature is 120℃ and the drying time is 25min.

[0073] S700: such as Figure 3 As shown, the second cavity pattern cutting is completed according to the cavity positioning marks on the surface of the stacked parts; the second cavity pattern cutting is to connect the cavity gaps that have been metallized through the cavity walls to form a closed cavity pattern.

[0074] S800: such as Figure 4 As shown, the isolation films on the upper and lower surfaces of the above-mentioned stacked components are removed, and the stacked components are stacked in order of layer number and pressed into a complete stacked body.

[0075] The technical solution of this invention realizes the metallization pattern printing of the inner cavity sidewall of multi-layer co-fired ceramics. The metallization thickness of the sidewall is uniform. Compared with the wall hanging of through holes at the edge of the cavity, the metallization area of ​​the cavity sidewall reaches more than 90%, which solves the problem of high-frequency signal crosstalk and can ensure the consistency between printing batches and production efficiency.

[0076] The above description is merely a preferred embodiment of the present invention and is not intended to limit the 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 method for printing metallized patterns on the inner cavity sidewall of a multilayer co-fired ceramic package, characterized in that, Includes the following steps: S100: Using green ceramic sheets and metallization paste, the surface patterns and through holes of each layer of green ceramic sheet are completed according to the multi-layer ceramic production process; S200: Group the green ceramic pieces according to the cavity pattern. Adjacent green ceramic pieces with the same cavity pattern are grouped together. Each group of green ceramic pieces is stacked and pressed together in order of layer number to form a stacked body. S300: Cover the upper and lower surfaces of the laminated parts formed in step S200 with an isolation film, and complete the first cavity gap cutting according to the cavity positioning marks on the surface of the laminated parts. The first cavity slot cutting was carried out using laser cutting to process each side wall of the cavity into slot channels with a certain width. The side walls were vertical, and the slot width was 0.3mm to 3mm. S400: The metallization paste is filled into the gaps of the stacked split cavities using a screen printing process. S500: The excess metallized slurry in the gaps of the multilayered split cavity is quickly removed by the slurry extraction platform; S600: Dry the metallization slurry on the sidewalls of the stacked split cavity; S700: Complete the second cavity graphic cutting according to the cavity positioning marks on the surface of the stacked split body; The second cavity pattern cutting is to connect the gaps of the cavity that have been metallized through the cavity walls to form a closed cavity pattern. S800: Remove the release film from the upper and lower surfaces of the laminated components, stack the laminated components in order of layer number, and press them together into a complete laminated body.

2. The method for printing metallized patterns on the inner cavity sidewall of a multilayer co-fired ceramic package according to claim 1, characterized in that: The multilayer ceramic manufacturing process includes the following steps: S101: Perforated green ceramic tile; S102: Metallization slurry for filling raw ceramic tiles; S103: Metallization paste for printing raw ceramic tiles.

3. The method for printing metallized patterns on the inner cavity sidewall of a multilayer co-fired ceramic package according to claim 1, characterized in that: The layer numbering order is based on the stacking of multiple co-fired ceramics. The raw ceramic pieces are arranged from bottom to top as layer 1, layer 2, ..., and so on, with the top layer being layer n, where n ≥ 2.

4. The method for printing metallized patterns on the inner cavity sidewall of a multilayer co-fired ceramic package according to claim 1, characterized in that: The isolation membrane on the surface of the laminated components is used to prevent contamination of the metallized patterns on the green ceramic surface. It is made of polyimide material that is sticky and resistant to high temperatures.

5. The method for printing metallized patterns on the inner cavity sidewall of a multilayer co-fired ceramic package according to claim 1, characterized in that: The screen printing process involves using a screen printing machine and a matching printing screen.

6. The method for printing metallized patterns on the inner cavity sidewall of a multilayer co-fired ceramic package according to claim 1, characterized in that: The slurry extraction platform includes a support plate (1), a positioning pin (2), a slurry extraction chamber (3), a baffle (4), an air intake pipe (5), and an air intake fan (6). The support plate (1) is placed on the upper part of the slurry extraction chamber (3) by the positioning pin (2). The upper part of the slurry extraction chamber (3) has an open structure. The bottom of the slurry extraction chamber (3) is connected to the air intake pipe (5). The air intake pipe (5) is connected to the air intake fan (6). The baffle (4) is installed in the slurry extraction chamber (3) by the support column and is located directly above the air intake pipe (5). The opening pattern of the support plate (1) is consistent with the gap pattern of the stacked split cavity.

7. The method for printing metallized patterns on the inner cavity sidewall of a multilayer co-fired ceramic package according to claim 1, characterized in that: In step S600, the drying temperature is between 50℃ and 150℃, and the drying time is between 5 min and 30 min.

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