Ceramic packaging shell and preparation method thereof

Abstract

The present invention provides a ceramic package shell and a preparation method thereof. The ceramic package shell comprises a ceramic body, a sealing surface pad arranged on the sealing surface of the ceramic body and a back surface pad arranged on the back surface of the ceramic body, a groove having one end connected to the sealing surface and the other end connected to the back surface is arranged on the side of the ceramic body, a side pad having one end connected to the sealing surface pad and the other end connected to the back surface pad is arranged on the inner wall of the groove, and a solder resist layer is arranged on the side pad. The present invention can prevent solder from flowing along the side pad to the side of the shell by arranging a solder resist layer on the side pad, avoids the arrangement of a front solder resist layer, and further avoids the problem of an increase in the size of the ceramic package shell and a decrease in the size of the sealing area due to the front solder resist layer.

Description

Technical Field

[0001] The present invention relates to the technical field of ceramic packaging, and in particular to a ceramic packaging shell and a preparation method thereof. Background Art

[0002] With the development of microwave semiconductor technology, the operating frequency of devices continues to increase, and the application frequency of ceramic package shells used to package chips has also increased. For high-frequency ceramic package shells, the grounding effect can be enhanced by grounding the pads on both sides of the RF pads, adding side pads, and directly connecting the sealing surface and the back pads to increase shielding and suppress resonance. However, in the sealing process of this structure, the solder will flow along the side pads to the side and even the back of the shell, resulting in poor package appearance and reduced reliability; therefore, a solder mask area needs to be set.

[0003] The traditional solder resist area is located outside the sealing area of ​​the front side of the ceramic package shell. However, the increase of solder resist will lead to an increase in the size of the ceramic package shell and a decrease in the size of the sealing area, affecting the miniaturization and sealing reliability of the device. Summary of the invention

[0004] The embodiment of the present invention provides a ceramic package shell to solve the problem that the increase of solder resist leads to an increase in the size of the ceramic package shell and a decrease in the size of the sealing area.

[0005] In the first aspect, an embodiment of the present invention provides a ceramic packaging shell, including a ceramic body, a sealing surface pad arranged on the sealing surface of the ceramic body, and a back side pad arranged on the back side of the ceramic body, the side surface of the ceramic body is provided with a groove with one end connected to the sealing surface and the other end connected to the back side, the inner wall of the groove is provided with a side pad with one end connected to the sealing surface pad and the other end connected to the back side pad, and the side pad is provided with a solder resist layer.

[0006] In a possible implementation manner, the solder resist layer is made of ceramic insulating material.

[0007] In a possible implementation, the solder resist layer is disposed at one end of the side pad sealing surface pad.

[0008] In a possible implementation, the ceramic body is a multi-layered sheet ceramic, and accordingly, the solder resist layer is disposed on a side pad corresponding to a layer of a sealing surface of the multi-layered sheet ceramic.

[0009] In a second aspect, an embodiment of the present invention provides a method for preparing a ceramic package shell, the method comprising:

[0010] Punching a hole in the sheet-like ceramic green body to obtain a hollow hole penetrating the ceramic green body;

[0011] Metallizing the sealing surface of the ceramic green body to obtain a sealing surface welding pad;

[0012] Metallizing the back side of the ceramic green body to obtain a back side pad;

[0013] Metallizing the inner wall of the hollow hole to form a side pad having one end connected to the sealing surface pad and the other end connected to the back surface pad;

[0014] Coating solder resist paste on the side pad to obtain a solder resist layer;

[0015] The ceramic package shell is obtained by cutting and sintering. After cutting, the hollow hole is divided into two, which respectively become side grooves of two ceramic package shells.

[0016] In a possible implementation, coating the solder resist paste on the side pad to obtain the solder resist layer includes:

[0017] Filling the hollow hole with solder resist paste;

[0018] Removing excess solder resist paste in the hollow hole to form a solder resist paste layer attached to the inner wall of the hollow hole;

[0019] The solder resist paste layer is dried to obtain a solder resist layer.

[0020] In a possible implementation manner, the solder resist layer is made of ceramic insulating material.

[0021] In a possible implementation, before the solder resist slurry is filled into the hollow holes, the method further includes: providing a barrier layer in the area outside the hollow holes on the surface of the ceramic green body, wherein the barrier layer is used to prevent the area outside the hollow holes from contacting the solder resist slurry.

[0022] In a possible implementation, the main body of the ceramic package shell is a multi-layered sheet ceramic, and the solder resist layer is disposed on a side pad corresponding to a layer of a sealing surface of the multi-layered sheet ceramic.

[0023] In a possible implementation, before the solder resist slurry is filled into the hollow hole, the method further includes: diluting the ceramic green body with an organic solvent to prepare the solder resist slurry.

[0024] The embodiment of the present invention provides a ceramic package shell, including a ceramic body, a sealing surface pad arranged on the sealing surface of the ceramic body, and a back surface pad arranged on the back surface of the ceramic body, the side surface of the ceramic body is provided with a groove with one end connected to the sealing surface and the other end connected to the back surface, the inner wall of the groove is provided with a side pad with one end connected to the sealing surface pad and the other end connected to the back surface pad, and the side pad is provided with a solder resist layer. By providing the solder resist layer on the side pad, it is achieved to prevent the solder from flowing along the side pad to the side of the shell, avoiding the provision of the front solder resist layer, thereby avoiding the problem of the ceramic package shell size increase and the sealing area size reduction caused by the front solder resist layer. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0026] Figure 1 is a schematic diagram of the front structure of a ceramic package shell provided by an embodiment of the present invention;

[0027] Figure 2 The embodiment of the present invention provides Figure 1 Schematic diagram of the longitudinal section structure at the dotted line A

[0028] Figure 3 It is a flow chart of the implementation of the method for preparing a ceramic packaging shell provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0029] In order to enable people in the technical field to better understand the present solution, the technical solution in the embodiment of the present solution will be clearly described below in conjunction with the drawings in the embodiment of the present solution. Obviously, the described embodiment is an embodiment of a part of the present solution, not all of the embodiments. Based on the embodiments in the present solution, all other embodiments obtained by ordinary technicians in the field without creative work should fall within the scope of protection of the present solution.

[0030] The term "including" and any other variations in the specification and claims of this solution and the above drawings mean "including but not limited to", and is intended to cover non-exclusive inclusions and is not limited to the examples listed in the text. In addition, the terms "first" and "second" are used to distinguish different objects, not to describe a specific order.

[0031] The following is a detailed description of the implementation of the present invention in conjunction with the specific drawings:

[0032] Figure 1 A schematic diagram of the cross-sectional structure of a ceramic package shell provided in an embodiment of the present invention; Figure 2 The embodiment of the present invention provides Figure 1 Schematic diagram of the longitudinal section structure at the dotted line A. Figure 1 , Figure 2The ceramic packaging shell includes a ceramic body 1, a sealing surface pad 2 arranged on the sealing surface of the ceramic body 1, and a back pad 3 arranged on the back of the ceramic body 1. The side of the ceramic body 1 is provided with a groove 4 with one end connected to the sealing surface and the other end connected to the back. The inner wall of the groove 4 is provided with a side pad 5 with one end connected to the sealing surface pad 2 and the other end connected to the back pad 3. The side pad 5 is provided with a solder resist layer 6.

[0033] The sealing surface is on the front side of the ceramic body 1, and a sealing surface pad 2 is arranged on the sealing surface. The sealing surface pad 2 is used in a sealing process to package the ceramic package shell and the cover plate into a closed cavity;

[0034] The back solder pad 3 is arranged on the back of the ceramic body 1 and is used for the ceramic package shell to connect to the external circuit;

[0035] The groove 4 is arranged on the outer side surface of the ceramic body 1, with one end connected to the sealing surface and the other end connected to the back surface; the groove 4 runs through the sealing surface and the back surface.

[0036] Exemplarily, the cross-sectional shape of the groove 4 may be semicircular, rectangular or V-shaped.

[0037] The side pad 5 is arranged on the inner wall of the groove 4, with one end connected to the sealing surface pad 2 and the other end connected to the back pad 3; the structure of the side pad 5 directly connecting the sealing surface pad 2 and the back pad 3 is a common structure of a high-frequency housing; during the sealing process, the solder will flow along the side pad 5 to the side or even the back of the housing;

[0038] The solder resist layer 6 is disposed on the side pad 5 to prevent the solder from flowing along the side pad 5 to the side of the housing.

[0039] In an optional embodiment, the solder resist layer 6 is made of ceramic insulating material.

[0040] Exemplary ceramic insulating materials include aluminum oxide, aluminum nitride, beryllium oxide, silicon carbide or boron nitride.

[0041] Exemplarily, the material of the solder resist layer 6 is the same as that of the ceramic body 1 ; the same material facilitates the use of the same process conditions in the subsequent sintering process without considering the compatibility of the materials.

[0042] In an optional embodiment, the solder resist layer 6 is disposed on one end of the side pad 5 sealing the surface pad 2 .

[0043] Exemplarily, the solder resist layer 6 may cover the entire side pad 5 .

[0044] In an optional embodiment, the ceramic body 1 is a multi-layered sheet ceramic, and accordingly, the solder resist layer 6 is disposed on a side pad 5 corresponding to a layer of the sealing surface of the multi-layered sheet ceramic.

[0045] In order to realize a complex ceramic packaging structure, the ceramic body 1 is composed of multiple layers of ceramics, each layer is individually structured and then laminated to form a complete ceramic body 1; each single layer is provided with a side welding pad 5; and the sealing surface layer is provided on the top of the ceramic body 1.

[0046] Exemplarily, the solder resist layer 6 is disposed on the side pad 5 corresponding to one layer of the sealing surface, and no solder resist layer 6 is disposed on the side pads 5 of other layers; the process steps are simplified, and the solder resist layer 6 preparation process is added during the preparation of the sealing surface layer to avoid adding the process step of setting the solder resist layer 6 for each layer.

[0047] A ceramic package shell provided by an embodiment of the present invention prevents solder from flowing along the side pads 5 to the side of the shell by setting a solder resist layer 6 on the side pads 5, thereby avoiding the need to set a front solder resist layer, thereby avoiding the problem of increased size of the ceramic package shell and reduced size of the sealing area due to the front solder resist layer.

[0048] Figure 3 The following is a flowchart of the method for preparing a ceramic package shell according to an embodiment of the present invention. Figure 3 , the preparation method comprises:

[0049] In step S1, a hole is punched on a sheet-like ceramic green body to obtain a hollow hole penetrating the ceramic green body.

[0050] Ceramic green body is made by mixing ceramic powder and organic solvent and drying and solidifying.

[0051] Exemplarily, the cross-sectional shape of the hollow hole may be circular, rectangular or diamond-shaped.

[0052] In step S2 , metallization is performed on the sealing surface of the ceramic green body to obtain a sealing surface pad 2 .

[0053] Exemplarily, the sealing surface pad 2 is obtained on the sealing surface of the ceramic green body by screen printing, coating tungsten slurry and drying.

[0054] In step S3 , metallization is performed on the back side of the ceramic green body to obtain a back side pad 3 .

[0055] Exemplarily, the back side pad 3 is obtained on the back side of the ceramic green body by screen printing, coating tungsten slurry and drying.

[0056] In step S4, metallization is performed on the inner wall of the hollow hole to form a side pad 5 having one end connected to the sealing surface pad 2 and the other end connected to the back surface pad 3.

[0057] The side pad 5 is arranged on the inner wall of the hollow hole, with one end connected to the sealing surface pad 2 and the other end connected to the back pad 3; the structure in which the side pad 5 is directly connected to the sealing surface pad 2 and the back pad 3 is a common structure of a high-frequency housing.

[0058] In step S5 , a solder resist paste is applied on the side pad 5 to obtain a solder resist layer 6 .

[0059] In an optional embodiment, coating the solder resist paste on the side pad 5 to obtain the solder resist layer 6 includes:

[0060] Filling the hollow hole with solder resist paste;

[0061] Removing excess solder resist paste in the hollow hole to form a solder resist paste layer attached to the inner wall of the hollow hole;

[0062] The solder resist paste layer is dried to obtain a solder resist layer 6 .

[0063] Exemplarily, the solder resist paste fills the hollow hole by flowing the solder resist paste into the hollow hole.

[0064] Exemplarily, excess solder resist paste in the hollow hole is removed by vacuum suction.

[0065] In an optional embodiment, the solder resist layer 6 is made of ceramic insulating material.

[0066] Exemplary ceramic insulating materials include aluminum oxide, aluminum nitride, beryllium oxide, silicon carbide or boron nitride.

[0067] Exemplarily, the material of the solder resist layer 6 is the same as that of the ceramic body 1 .

[0068] In an optional embodiment, before the solder resist slurry is filled into the hollow holes, the method further includes: providing a barrier layer in the area outside the hollow holes on the surface of the ceramic green body, wherein the barrier layer is used to prevent the area outside the hollow holes from contacting the solder resist slurry.

[0069] Exemplarily, the barrier layer is produced by a screen printing process.

[0070] In an optional embodiment, before the solder resist slurry is filled into the hollow hole, the method further includes: diluting the ceramic green body with an organic solvent to prepare the solder resist slurry.

[0071] In an optional embodiment, the main body of the ceramic package shell is a multi-layer ceramic sheet, and the solder resist layer 6 is disposed on the side pad 5 corresponding to a layer of the sealing surface of the multi-layer ceramic sheet.

[0072] In order to realize a complex ceramic packaging structure, the ceramic body 1 is composed of multiple layers of ceramics, each layer is individually structured and then laminated to form a complete ceramic body 1; each single layer is provided with a side welding pad 5; and the sealing surface layer is provided on the top of the ceramic body 1.

[0073] Exemplarily, the solder resist layer 6 is disposed on the side pad 5 corresponding to one layer of the sealing surface, and no solder resist layer 6 is disposed on the side pads 5 of other layers; the process steps are simplified, and the solder resist layer 6 preparation process is added during the preparation of the sealing surface layer to avoid adding the process step of setting the solder resist layer 6 for each layer.

[0074] In step S6, a ceramic package shell is obtained by cutting and sintering. After cutting, the hollow hole is divided into two, which respectively become the side grooves 4 of the two ceramic package shells.

[0075] The ceramic packaging shell preparation method provided in the embodiment of the present invention, through batch processing of ceramic green bodies, cutting and separating them into multiple ceramic packaging shells, realizes batch setting of solder resist layers 6 on the side pads 5, thereby preventing the solder from flowing along the side pads 5 to the side of the shell, avoiding the setting of the front solder resist layer, and further avoiding the problem of increased size of the ceramic packaging shell and reduced size of the sealing area due to the front solder resist layer.

[0076] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features may be replaced by equivalents. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A ceramic package shell, comprising a ceramic body, a sealing surface pad provided on a sealing surface of the ceramic body, and a back surface pad provided on a back surface of the ceramic body, characterized in that: The side of the ceramic body is provided with a groove with one end connected to the sealing surface and the other end connected to the back surface. The inner wall of the groove is provided with a side pad with one end connected to the sealing surface pad and the other end connected to the back pad. The side pad is provided with a solder resist layer.

2. The ceramic package shell according to claim 1, characterized in that: The solder resist layer is made of ceramic insulating material.

3. The ceramic package shell according to claim 1, characterized in that: The solder resist layer is arranged on one end of the side pad close to the sealing surface pad.

4. The ceramic package shell according to claim 3, characterized in that: The ceramic body is a multi-layered sheet-like ceramic, and correspondingly, the solder resist layer is arranged on a side pad corresponding to a layer of the sealing surface of the multi-layered sheet-like ceramic.

5. A method for preparing a ceramic packaging shell, characterized in that: The preparation method comprises: Punching a hole in the sheet-like ceramic green body to obtain a hollow hole penetrating the ceramic green body; Metallizing the sealing surface of the ceramic green body to obtain a sealing surface welding pad; Metallizing the back side of the ceramic green body to obtain a back side pad; Metallizing the inner wall of the hollow hole to form a side pad having one end connected to the sealing surface pad and the other end connected to the back surface pad; Coating solder resist paste on the side pad to obtain a solder resist layer; After obtaining the solder resist layer, the ceramic package shell is obtained by cutting and sintering. After cutting, the hollow hole is divided into two, which respectively become the side grooves of the two ceramic package shells.

6. The method for preparing a ceramic package shell according to claim 5, characterized in that: The step of coating the solder resist paste on the side pad to obtain the solder resist layer comprises: Filling the hollow hole with solder resist paste; Removing excess solder resist paste in the hollow hole to form a solder resist paste layer attached to the inner wall of the hollow hole; The solder resist paste layer is dried to obtain a solder resist layer.

7. The method for preparing a ceramic package shell according to claim 6, characterized in that: The solder resist layer is made of ceramic insulating material.

8. The method for preparing a ceramic package shell according to claim 6, characterized in that: Before filling the hollow holes with solder mask paste, it also includes: A barrier layer is arranged in the area outside the hollow holes on the surface of the ceramic green body, and the barrier layer is used to prevent the area outside the hollow holes from contacting with the solder resist paste.

9. The method for preparing a ceramic package shell according to claim 6, characterized in that: The main body of the ceramic package shell is a multi-layered sheet ceramic, and the solder resist layer is arranged on a side solder pad corresponding to a sealing surface of the multi-layered sheet ceramic.

10. The method for preparing a ceramic package shell according to claim 6, characterized in that: Before filling the hollow holes with solder mask paste, it also includes: The ceramic green body is diluted with an organic solvent to prepare a solder resist paste.

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