Method for chamfering side wall of embedded cavity of chip device

Abstract

The invention relates to a method for chamfering the side wall of an embedded cavity of a chip device, and belongs to the technical field of chip device manufacturing. The method comprises the following steps: manufacturing a cavity side wall slurry hanging plate and a whole-surface screen printing plate according to the size of an embedded cavity of the chip device; based on a cavity side wall paste hanging plate, ceramic powder adhesive cement is printed on the cavity side wall of the cavity layer base plate through the silk-screen printing technology, an arc-shaped adhesive column is formed on the cavity side wall, and the cavity layer base plate subjected to primary treatment is obtained after drying; based on a whole-surface screen printing plate, whole-surface adhesive cement is printed on the cavity layer substrate subjected to primary treatment through the screen printing technology, and a chamfered cavity layer is obtained after drying; and printing lamination glue on the upper functional layer and the lower functional layer of the chip device, laminating the upper functional layer, the chamfered cavity layer and the lower functional layer in sequence, and carrying out lamination, cutting and sintering to obtain the chip device with the chamfered cavity side wall. According to the invention, the chamfer structure can be formed on the side wall of the embedded cavity of the chip device, and the thermal stress of the cavity in a high-temperature state can be reduced.

Description

Technical Field

[0001] The invention relates to a method for chamfering the side wall of a cavity buried in a chip-type device, belonging to the technical field of chip-type device manufacturing. Background Art

[0002] The chip device composed of the upper functional layer, the middle cavity layer and the lower functional layer requires the middle cavity to be closely combined with the upper and lower functional layers and the molding cavity to have high precision. The buried cavity in the chip device can be used for insulation, gas storage, heat dissipation, etc. Its shape is generally rectangular, and the specific size varies slightly depending on the type of device. As the width and height of the cavity increase, the difficulty of cavity production increases, and the risk of cracking at the right-angle edge of the cavity under high-temperature working conditions will increase, especially for large-sized buried cavities with a depth greater than 0.3mm and a length greater than 50mm. It is easy to crack along the right-angle edge under the action of thermal stress or even delamination, resulting in the failure of the chip device.

[0003] Designing the sidewall of the embedded cavity of the chip device into an inclined surface or an arc-shaped surface can effectively improve the stability of the embedded cavity under high-temperature working conditions. However, the processing technology of the embedded cavity itself is relatively complicated and difficult to manufacture. It is even more difficult to chamfer the embedded cavity. Currently, there is a lack of cavity sidewall chamfering technology on the market. How to complete the chamfering during the embedded cavity manufacturing process is one of the next research focuses. Summary of the invention

[0004] In order to solve the problem that thermal stress in a buried cavity of a chip device (especially a buried deep cavity with a cavity length greater than 50 mm, a depth greater than 0.3 mm, and a large aspect ratio) is prone to cause cavity cracks or even delamination failure under high temperature conditions, the present invention provides a side wall chamfering method for a buried cavity of a chip device, including cavity substrate scribing, chamfering process design and processing, and the buried cavity with chamfered side walls can be obtained by coordinating processes such as screen printing, lamination and sintering, thereby reducing the thermal stress of the cavity when the chip device is working at high temperature, avoiding the risk of cavity cracking, and improving the safety and reliability of the chip device.

[0005] In order to achieve the above purpose / solve the above technical problems, the present invention is implemented by adopting the following technical solutions: The present invention provides a method for chamfering the side wall of a buried cavity in a chip device, comprising the following steps: According to the size of the cavity buried in the chip device, the cavity side wall slurry plate and the whole screen plate are produced; The cavity side wall paste plate is aligned with the cavity layer substrate of the chip device through the printing alignment hole, and the ceramic powder glue is printed on the cavity side wall of the cavity layer substrate by screen printing technology to form arc-shaped glue columns on the cavity side wall, and the cavity layer substrate after initial treatment is obtained after drying; Aligning the entire screen plate with the pre-processed cavity layer substrate through printing alignment holes, printing the entire surface of glue on the pre-processed cavity layer substrate using screen printing technology, and obtaining the chamfered cavity layer after drying; The lamination glue is printed on the upper functional layer and the lower functional layer of the chip device by screen printing technology, and the upper functional layer, the chamfered cavity layer and the lower functional layer are stacked in sequence and laminated, cut and sintered to obtain a chip device with chamfered cavity sidewalls.

[0006] Furthermore, the cavity side wall slurry plate design includes an annular slurry gap and a printing alignment hole, wherein one slurry gap corresponds to an embedded cavity of a chip device.

[0007] Furthermore, the outer dimension of the paste gap is expanded by 30-50 μm based on the size of the buried cavity of the chip device, and the inner dimension of the paste gap is expanded by 50-80 μm based on the size of the cavity.

[0008] Furthermore, the entire screen plate is designed to deduct the cavity pattern corresponding to the cavity layer, and the printed pattern area of ​​the entire screen plate is the non-cavity area of ​​the cavity layer except the cavity pattern; the entire screen plate is also designed to include printing alignment holes.

[0009] Furthermore, the size of the entire screen plate minus the cavity area is shrunk by 30-50 μm based on the size of the cavity buried in the chip device.

[0010] Furthermore, before printing and lamination, a laser puncher is used to cut positioning holes, printing alignment holes and cavity patterns on the upper functional layer, lower functional layer and cavity layer of the chip device, wherein the printing alignment holes are used for positioning during printing, and the positioning holes are used for positioning during lamination.

[0011] Furthermore, the cavity side wall slurry plate and the entire screen plate are both made of steel plates.

[0012] Furthermore, the thickness of the cavity side wall slurry plate is in the range of 0.02-0.05 mm, and the viscosity of the ceramic powder slurry is in the range of 100-150 Pa×S.

[0013] Furthermore, the cavity side wall slurry plate is aligned with the cavity layer substrate of the chip device through printing alignment holes. When printing on the cavity side wall of the cavity layer substrate using screen printing technology, the pressure of the scraper bar is used to make the ceramic powder slurry flow into the slurry lowering gap to form an arc-shaped glue column above the cavity side wall.

[0014] Furthermore, the drying temperature ranges from 70 to 80° C., and the drying time ranges from 20 to 30 minutes.

[0015] Compared with the prior art, the present invention has the following beneficial effects: The present invention proposes a method for chamfering the side wall of a cavity buried in a chip-type device. A chamfered structure is produced on the side wall of the cavity buried in the chip-type device by hanging a slurry plate on the side wall of the cavity and a whole-surface screen plate, and the right-angle edge of the buried cavity is processed into an arc angle, which can reduce the thermal stress of the right-angle edge of the cavity during the high-temperature operation of the chip-type device, and avoid cracks or even delamination failure along the right-angle edge of the chip core substrate. The method of the present invention is particularly suitable for chamfering the side wall of a buried cavity with a depth greater than 0.3mm, which is beneficial to improving the pressure resistance performance of sensors with large-sized buried cavities and can improve product stability.

[0016] The method of the present invention is simple and practical to operate, has low production cost, and uses a mature and stable process. The method of the present invention can be used to mass-produce embedded cavities with chamfered side walls, has high production efficiency, can effectively reduce the risk of high-temperature cracking and failure of products, and improve product reliability.

[0017] The present invention uses a paste with a composition close to that of raw porcelain. On the one hand, it can ensure the matching of printing and sintering of raw porcelain and paste, avoid printing pinholes in the printing process, poor bonding between pattern diffusion and substrate, and bending and delamination due to material mismatch in the sintering process; on the other hand, by adjusting the slurry parameters and screen printing parameters, the amount of slurry can be effectively controlled, thereby controlling the arc angle of the cavity side wall. Printing the entire surface of the surface with glue can ensure the flatness and bonding of the lamination, ensure the molding quality of the cavity with chamfered side walls, and reduce the risk of high-temperature cracking and failure of the product. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 The figure is a schematic diagram of the steps of a method for chamfering the sidewall of a buried cavity in a chip device provided by an embodiment of the present invention; Figure 2 The figure is a schematic diagram of the structure of the cavity side wall pulp hanging plate in an embodiment of the present invention; Figure 3 The figure shows a schematic diagram of the structure of the entire screen in an embodiment of the present invention; Figure 4 It is a schematic diagram of processing a glue column on a cavity side wall by using a cavity side wall hanging slurry plate in an embodiment of the present invention; Figure 5 It is a schematic diagram of printing the entire surface of glue paste on the cavity layer using the entire surface screen in an embodiment of the present invention; Figure 6 FIG. 1 is a schematic diagram of the structure of a chip-type device with chamfered cavity sidewalls in an embodiment of the present invention; Among them, 1 is the paste hanging plate on the side wall of the cavity, 101 is the lower paste gap, 2 is the whole screen plate, 201 is the cavity area deducted, 3 is the printing alignment hole, 4 is the cavity layer, 5 is the upper functional layer, 6 is the lower functional layer, 7 is the glue column, 8 is the whole surface glue, and 9 is the chamfer. DETAILED DESCRIPTION

[0019] The technical solution of the present invention is described in detail below through the accompanying drawings and specific embodiments. It should be understood that the embodiments of the present invention and the specific features in the embodiments are detailed descriptions of the technical solution of the present invention, rather than limitations on the technical solution of the present invention. The embodiments of the present invention and the technical features in the embodiments may be combined with each other unless there is a conflict.

[0020] This embodiment introduces a method for chamfering the sidewall of a buried cavity in a chip device. Figure 1 As shown, the following steps are included: Step A: design and manufacture the cavity sidewall paste plate 1 and the whole-surface screen plate 2 according to the size of the cavity buried in the chip device.

[0021] In the present invention, the cavity side wall paste plate and the whole screen plate are both made of steel plates. The cavity side wall paste plate is used to paste the top of the side wall of the cavity buried in the chip device to form an arc-shaped protruding structure. The whole screen plate is used to print lamination glue on the cavity layer of the chip device, which is combined with the protruding structure formed by the cavity side wall paste plate to form a cavity chamfer structure after lamination.

[0022] like Figure 2 As shown, the surface of the cavity side wall paste plate is designed with multiple annular paste gaps 101, and the size of each paste gap is designed according to the size of the cavity buried in the chip device. Specifically, the outer size of the paste gap is 30-50μm larger than the cavity size, and the inner size of the paste gap is 50-80μm larger than the cavity size. Such size design can ensure that there are sufficient pores on the cavity side wall for paste during printing, and is conducive to controlling the amount of paste.

[0023] The edge of the cavity side wall slurry plate is provided with a plurality of printing alignment holes 3 for positioning during the printing process. Generally, the printing alignment holes are provided at the four corners of the cavity side wall slurry plate.

[0024] In the present invention, each descending slit in the cavity side wall slurry plate corresponds to a cavity. Therefore, one cavity side wall slurry plate can process the cavity layers of multiple chip devices at the same time. The number, spacing, arrangement, etc. of the descending slits in the cavity side wall slurry plate can be changed according to actual needs.

[0025] like Figure 3 As shown, the whole screen is designed to deduct the cavity pattern corresponding to the cavity layer. The size of the deducted cavity area 201 on the whole screen is shrunk by 30-50μm based on the cavity size. The paste is printed on the surface of the cavity layer of the chip device through the whole screen. Due to the existence of the deducted cavity area, the printed pattern area of ​​the whole screen is the non-cavity area of ​​the cavity layer except the cavity pattern. Combined with the protruding structure of the cavity side wall printed on the cavity side wall by the cavity side wall hanging paste plate, a smooth chamfer can be formed to ensure the integrity and flatness of the whole surface printing of the paste.

[0026] The edge of the whole screen is also provided with printing alignment holes. The positions of the printing alignment holes of the cavity side wall paste plate and the whole screen are consistent with the positions of the printing alignment holes on the chip device cavity layer substrate. During the printing process, the cavity side wall paste plate or the whole screen is aligned with the chip device cavity layer substrate by aligning the printing alignment holes to ensure the printing effect.

[0027] Step B: Before printing and lamination, use a laser puncher to cut corresponding positioning holes, print alignment holes and cavity patterns on the upper functional layer 5, the lower functional layer 6 and the cavity layer 4 of the chip device.

[0028] Step C, aligning the cavity side wall paste plate with the cavity layer substrate of the chip device through the printing alignment hole, printing a ceramic powder paste with a composition similar to that of raw porcelain on the cavity side wall of the cavity layer substrate by screen printing technology, adjusting the printing parameters and the paste parameters to ensure that the paste can form an arc angle on the cavity side wall and control the size of the arc angle, drying at 70-80°C for 20-30 minutes to solidify the ceramic powder paste, and obtaining the cavity layer substrate after initial treatment.

[0029] like Figure 4 As shown, after the cavity side wall paste plate is aligned with the cavity layer substrate, the paste gap and the cavity on the cavity layer substrate are actually staggered. During printing, the pressure of the scraper strip can be used to make the paste flow into the paste gap, thereby forming an extruded glue column 7 above the side wall of the cavity layer substrate, and the cross section of the glue column presents an arc-shaped convex structure. The shape of the glue column above the side wall is closely related to the viscosity of the paste. If the paste is too thin, the paste will pass through the other side along the entire side wall in a thin layer, and the chamfer in the cavity cannot be made. If the paste is too thick, it will be difficult for the paste to pass smoothly through the paste gap.

[0030] In order to further control the amount of slurry on the surface and improve the chamfering effect of the side wall, the thickness of the slurry plate on the side wall of the hollow cavity in the present invention needs to be controlled within the range of 0.02-0.05mm. At the same time, it is necessary to adjust the screen printing parameters according to the specific chip device preparation requirements, such as folding distance, pressure, speed, slurry viscosity, etc. In the embodiment of the present invention, a ceramic powder slurry with a composition close to that of raw porcelain is used, and the slurry viscosity is controlled between 100-150Pa×S, which is conducive to controlling the amount of slurry while ensuring the size of the arc angle of the side wall after firing.

[0031] The specific components of the ceramic powder slurry are configured as required according to the substrate of the chip device. In the embodiment of the present invention, the slurry components used are zirconia ceramic powder, resin and organic solvent, wherein the solid content of zirconia ceramic powder is 55-65%, the solid content of resin is 20-30%, and the organic solvent is appropriate.

[0032] Step D: align the entire screen with the initially processed cavity layer substrate through the printing alignment holes, print the entire surface of the adhesive paste on the initially processed cavity layer substrate using screen printing technology, and dry it at 70-80°C for 20-30 minutes to solidify the ceramic powder adhesive paste to obtain the chamfered cavity layer.

[0033] according to Figure 4 It can be seen that the top of the glue column above the side wall of the cavity layer substrate after the initial treatment is often higher than the upper surface of the cavity layer substrate. In order to ensure the flatness of the subsequent lamination and the bonding performance of the cavity layer and the upper and lower functional layers, it is necessary to print the entire surface of the glue paste 8 on the cavity layer substrate through the entire screen plate so that the height of the newly printed glue paste is flush with the top of the glue column above the side wall. The results are shown in FIG. Figure 5 shown.

[0034] Step E: Print lamination glue on the upper functional layer and the lower functional layer of the chip device by screen printing technology, stack the upper functional layer, the chamfered cavity layer and the lower functional layer in sequence through the positioning holes, and perform lamination, cutting and sintering to obtain a chip device with chamfered cavity sidewalls, such as Figure 6 As shown, after the upper and lower functional layers are laminated and combined with the cavity layer, an arc-shaped chamfer 9 is formed on the side wall of the buried cavity in the chip-type device.

[0035] If the filling lamination method is adopted, after the side wall of the cavity layer is slurried, a suitable sacrificial material is filled in the cavity during stacking, and a laminate is formed with the upper and lower functional layers during lamination.

[0036] The present invention uses a cavity side wall paste plate and a full-surface screen plate to make a chamfered structure on the side wall of the buried cavity of the chip device, and processes the right-angle edge of the buried cavity into an arc angle, which can reduce the thermal stress of the right-angle edge of the cavity during the high-temperature operation of the chip device, avoid cracks or even delamination failure along the right-angle edge of the chip core substrate, and is conducive to improving the pressure resistance performance of sensors containing large-sized buried cavities, and can improve product stability. The method of the present invention is simple and practical to operate, has low production cost, and the process used is mature and stable. The method of the present invention can be used to mass-produce buried cavities with chamfered side walls, with high production efficiency, and can effectively reduce the risk of high-temperature cracking and failure of products, and improve product reliability.

[0037] The present invention uses a paste with a composition close to that of raw porcelain. On the one hand, it can ensure the matching of printing and sintering of raw porcelain and paste, avoid printing pinholes in the printing process, poor bonding between pattern diffusion and substrate, and bending and delamination due to material mismatch in the sintering process; on the other hand, by adjusting the slurry parameters and screen printing parameters, the amount of slurry can be effectively controlled, thereby controlling the arc angle of the cavity side wall. Printing the entire surface of the surface with glue can ensure the flatness and bonding of the lamination, ensure the molding quality of the cavity with chamfered side walls, and reduce the risk of high-temperature cracking and failure of the product.

[0038] The embodiments of the present invention are described above in conjunction with the accompanying drawings, but the present invention is not limited to the above-mentioned specific implementation methods. The above-mentioned specific implementation methods are merely illustrative and not restrictive. Under the enlightenment of the present invention, ordinary technicians in this field can also make many forms without departing from the scope of protection of the purpose of the present invention and the claims, which all fall within the protection of the present invention.

Claims

1. A method for chamfering the sidewall of a buried cavity in a chip device, characterized in that: The steps include: According to the size of the cavity buried in the chip device, the cavity side wall slurry plate and the whole screen plate are produced; The cavity side wall paste plate is aligned with the cavity layer substrate of the chip device through the printing alignment hole, and the ceramic powder glue is printed on the cavity side wall of the cavity layer substrate by screen printing technology to form arc-shaped glue columns on the cavity side wall, and the cavity layer substrate after initial treatment is obtained after drying; Aligning the entire screen plate with the pre-processed cavity layer substrate through printing alignment holes, printing the entire surface of glue on the pre-processed cavity layer substrate using screen printing technology, and obtaining the chamfered cavity layer after drying; The lamination glue is printed on the upper functional layer and the lower functional layer of the chip device by screen printing technology, and the upper functional layer, the chamfered cavity layer and the lower functional layer are stacked in sequence and laminated, cut and sintered to obtain a chip device with chamfered cavity sidewalls.

2. The method for chamfering the sidewall of a buried cavity in a chip device according to claim 1, characterized in that: The design of the paste-hanging plate on the side wall of the cavity includes an annular paste-laying gap and a printing alignment hole, wherein one paste-laying gap corresponds to an embedded cavity of a chip-type device.

3. The method for chamfering the sidewall of a buried cavity in a chip device according to claim 2, characterized in that: The outer dimension of the paste gap is expanded by 30-50 μm based on the size of the buried cavity in the chip device, and the inner dimension of the paste gap is expanded by 50-80 μm based on the size of the cavity.

4. The method for chamfering the sidewall of a buried cavity in a chip device according to claim 1, characterized in that: The whole screen plate is designed to deduct the cavity pattern corresponding to the cavity layer, and the printed pattern area of ​​the whole screen plate is the non-cavity area of ​​the cavity layer except the cavity pattern; the whole screen plate is also designed to include printing alignment holes.

5. The method for chamfering the sidewall of a buried cavity in a chip device according to claim 4, characterized in that: The size of the cavity area deducted from the entire screen is shrunk by 30-50μm based on the size of the cavity buried in the chip device.

6. The method for chamfering the sidewall of a buried cavity in a chip device according to claim 1, characterized in that: Before printing and lamination, a laser puncher is used to cut positioning holes, printing alignment holes and cavity patterns on the upper functional layer, lower functional layer and cavity layer of the chip device, wherein the printing alignment holes are used for positioning during printing, and the positioning holes are used for positioning during lamination.

7. The method for chamfering the sidewall of a buried cavity in a chip device according to claim 2 or 4, characterized in that: The cavity side wall slurry plate and the entire screen plate are made of steel plates.

8. The method for chamfering the sidewall of a buried cavity in a chip device according to claim 1, characterized in that: The thickness of the cavity side wall slurry plate is in the range of 0.02-0.05 mm, and the viscosity of the ceramic powder slurry is in the range of 100-150 Pa×S.

9. The method for chamfering the sidewall of a buried cavity in a chip device according to claim 1, characterized in that: The cavity side wall slurry plate is aligned with the cavity layer substrate of the chip device through the printing alignment hole. When the cavity side wall of the cavity layer substrate is printed by screen printing technology, the pressure of the scraper strip is used to make the ceramic powder slurry flow into the slurry lowering gap to form an arc-shaped glue column above the cavity side wall.

10. The method for chamfering the sidewall of a buried cavity in a chip device according to claim 1, characterized in that: The drying temperature range is 70-80℃, and the drying time range is 20-30min.

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