A pressure module bonding coating method

Abstract

The application relates to a pressure module bonding coating method, which comprises the following steps: in step one, a ceramic base containing a circuit layer and a ceramic diaphragm containing a circuit layer are connected through a bonding layer, via holes on the ceramic base are aligned with connecting contact positions of the ceramic diaphragm, the bonding layer does not cover the connecting contacts, and the upper end of the via hole on the ceramic base is subjected to a metallization treatment to form a metal covering layer; in step two, conductive paste with fluidity is injected into the via hole to form a conductive layer on the surface and the bottom of the via hole, and the metal covering layer is connected with the connecting contacts through the conductive layer; and in step three, heating is conducted through a heating device to solidify the conductive layer, so that the circuit layers attached to the ceramic base and the ceramic diaphragm are connected. The application has the effects of reducing paste injection and explosion, realizing safe and reliable coating, and reducing cost.

Description

Technical Field

[0001] This application relates to pressure sensors, and more particularly to a method for bonding and coating pressure modules. Background Technology

[0002] The pressure sensor includes a ceramic base and a ceramic diaphragm, which are separated by an insulating material. Several through holes are formed on the ceramic base, and the inner wall of the through holes is metallized to form a metal coating layer. Contact points are set below the through holes to cooperate with the ceramic diaphragm.

[0003] Chinese patent publication number 110132453 discloses a pressure module bonding coating method. First, the ceramic diaphragm, bonding layer, ceramic components and connection points are assembled. Then, the solder paste in the through hole is melted by heating and then cooled. The solidification of the solder paste realizes the circuit bonding connection between the ceramic base and the ceramic diaphragm.

[0004] Regarding the aforementioned technologies, the inventors believe that they have the following drawbacks: the grouting is relatively thick and requires a large amount, making it prone to cracking, and the cost is also relatively high. Summary of the Invention

[0005] This application provides a ceramic pressure module bonding method that reduces excessive slurry injection and achieves safe and reliable coating while lowering costs.

[0006] This application provides a technical solution using the following approach:

[0007] A pressure module bonding coating method includes the following steps:

[0008] Step 1 Assembly: The ceramic base containing the circuit layer and the ceramic diaphragm containing the circuit layer are bonded and fixed together by the bonding layer. Several through holes are opened on the ceramic base. The through holes are aligned with the connection contact points of the ceramic diaphragm. The bonding layer does not cover the connection contact points. The part of the through hole away from the connection contact point is metallized to form a metal cover layer that is attached to the upper half of the through hole.

[0009] Step 2: Injecting fluid conductive paste into the via with a metal capping layer at the top. The height of the injected conductive paste is lower than the end of the metal capping layer near the connection point. Then, compressed gas at a certain pressure is blown into the via. Under the action of gas pressure, the conductive paste injected into the via is blown away and thinned. The blown conductive paste spreads evenly upward and covers the bottom of the metal capping layer, so that a connected conductive paste film adheres to the inner surface and bottom of the via, forming a conductive layer. The metal capping layer and the connection point are connected and conductive through the conductive layer.

[0010] Step 3: Curing: Heating is performed using a heating device to cure the conductive layer and make it adhere tightly to the inner surface of the via, thus achieving the connection between the circuit layer of the ceramic base and the circuit layer of the ceramic film.

[0011] By adopting the above technical solution, the conductive paste has a certain fluidity, which can fill the space between the metal cover layer and the contact points relatively fully. A conductive layer is formed only on the surface and bottom of the via, the paste is not too thick, it is less prone to cracking, and costs are reduced. When air is blown into the via, the conductive paste inside diffuses and moves upwards under the gas pressure, adhering to the via wall and eventually contacting the lower surface of the metal cover layer. This achieves the connection between the ceramic base circuit and the ceramic diaphragm circuit, ensuring the connection while further reducing the thickness of the conductive layer adhering to the inner wall of the via, effectively reducing material costs.

[0012] Optionally, when blowing air into the through hole, the air outlet is located at the central axis of the through hole.

[0013] By adopting the above technical solution, air is blown towards the center, causing the conductive paste to spread outwards relatively evenly, forming a relatively even conductive layer on the surface of the via.

[0014] Optionally, when blowing air into the through hole, the air outlet blows air vertically into the through hole.

[0015] By adopting the above technical solution, blowing air vertically downwards is also to ensure that the conductive paste is spread out more evenly in all directions, and the conductive paste forms a more even conductive layer on the surface of the via.

[0016] Optionally, the conductive paste is conductive silver paste.

[0017] In summary, this application includes at least one of the following beneficial technical effects:

[0018] 1. A conductive layer is formed on the surface and bottom of the via. The metal cover layer and the contact point are connected through the conductive layer. The conductive layer is only formed on the surface and bottom of the via. The paste is not too thick, which makes it less likely to crack and reduces costs.

[0019] 2. Blow air towards the center to make the conductive paste spread outwards relatively evenly, forming a relatively even conductive layer on the surface of the via. Attached Figure Description

[0020] Figure 1 This is a structural schematic diagram of the pressure module in this application.

[0021] Figure 2 This is a front view of the pressure module in this application.

[0022] Figure 3 This is a schematic diagram of the structure when the pressure module of this application injects conductive slurry.

[0023] Figure 4 This is a schematic diagram of the structure of the pressure module of this application after blowing air onto the conductive slurry.

[0024] Explanation of reference numerals in the attached diagram: 1. Ceramic base; 11. Via; 2. Bonding layer; 21. Through hole; 3. Ceramic diaphragm; 4. Metal overlay; 5. Connecting contact point; 6. Conductive layer. Detailed Implementation

[0025] The following is in conjunction with the appendix Figure 1-4 This application will be described in further detail.

[0026] Reference Figure 1 and Figure 2 This application discloses a pressure module bonding coating method, which includes a ceramic base 1, a ceramic diaphragm 3, and a bonding layer 2. Both the ceramic base 1 and the ceramic diaphragm 3 are provided with circuit layers, and the ceramic base 1 and the ceramic diaphragm 3 are connected through the bonding layer 2. Through-holes 11 are provided on the ceramic base 1, and connection contact points 5 are provided on the ceramic diaphragm 3.

[0027] The first step of the pressure module bonding coating method is assembly, where the ceramic base 1 and the ceramic diaphragm 3 are connected by the bonding layer 2. At this time, the bonding layer 2 cannot completely cover the connection contact point 5. The via 11 is aligned with the connection contact point 5. The part of the via 11 away from the connection contact point 5 is metallized to form a metal cover layer 4. The metal cover layer 4 partially enters the via 11. The metal cover layer 4 does not need to completely cover the surface of the via 11.

[0028] Step two involves injection of a fluid conductive paste into the via 11. The paste is injected into the via 11 at a height lower than the metal capping layer 4 and close to the end of the contact point 5. Then, compressed gas at a certain pressure is blown into the via 11. Under the pressure of the gas, the conductive paste diffuses towards the surface of the via 11 and moves upwards along the surface. The injected conductive paste thins out as it is blown away, spreading evenly upwards and covering the bottom of the metal capping layer 4. A thin film of conductive paste adheres to the inner surface and bottom of the via 11, thus connecting the conductive paste to the metal capping layer 4, forming a conductive layer 6 on the surface and bottom of the via 11. When blowing air into the via 11, the air outlet is located at the central axis of the via 11, and the air is blown vertically into the via 11.

[0029] Step three is curing, which involves heating the conductive layer 6 using a heating device to achieve electrical connection between the ceramic base 1 and the ceramic membrane 3. The curing temperature varies depending on the selected slurry.

[0030] The above are all preferred embodiments of this application, and are not intended to limit the scope of protection of this application. Therefore, all equivalent changes made in accordance with the structure, shape and principle of this application should be covered within the scope of protection of this application.

Claims

1. A pressure module bonding coating method, characterized in that: Includes the following steps, Step 1 Assembly: The ceramic base (1) containing the circuit layer and the ceramic diaphragm (3) containing the circuit layer are bonded and fixed by the bonding layer (2). The ceramic base (1) has several through holes (11). The through holes (11) are aligned with the connection contact (5) of the ceramic diaphragm (3). The bonding layer (2) does not cover the connection contact (5). The part of the through hole (11) away from the connection contact (5) is metallized to form a metal cover layer (4) which is attached to the upper part of the through hole (11). Step 2: Injecting fluid conductive paste into the via (11) with metal cover layer (4) attached to the upper end. The height of the injected conductive paste is lower than the end of the metal cover layer (4) near the connection point (5). Then, compressed gas with a certain pressure is blown into the via (11). Under the action of gas pressure, the conductive paste injected into the via (11) is blown away and becomes thinner. The blown conductive paste spreads evenly upward and covers the bottom of the metal cover layer (4), so that a layer of connected conductive paste film adheres to the inner surface and bottom of the via (11), forming a conductive layer (6). The metal cover layer (4) and the connection point (5) are connected and connected through the conductive layer (6). Step 3: Curing: The conductive layer (6) is cured by heating with a heating device and tightly adhered to the inner surface of the via (11), thereby achieving the connection between the circuit layer of the ceramic base (1) and the circuit layer of the ceramic film (3).

2. The pressure module bonding coating method according to claim 1, characterized in that: When air is blown into the through hole (11), the air outlet is located at the central axis of the through hole (11).

3. The pressure module bonding coating method according to claim 1, characterized in that: When blowing air into the through hole (11), the air outlet blows air vertically into the through hole (11).

4. The pressure module bonding coating method according to claim 1, characterized in that: The conductive paste is a conductive silver paste.

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