Leadless package structure of pressure sensor

Abstract

The utility model discloses a leadless packaging structure of pressure sensor, including sensitive chip, metal tube shell, insulating baseplate and conductive contact pin, the support layer of sensitive chip is provided with blind hole, and a plurality of metal electrodes are arranged in the blind hole, and the metal electrode is connected with the conductive contact pin through the conductive sintered body, and the sensitive chip is connected with the metal electrode through the conductive sintered body and the conductive contact pin to support and form the overhanging structure, and the insulating baseplate is connected with the conductive contact pin and the metal tube shell below the overhanging structure. The utility model discloses sensitive chip is connected with the conductive contact pin and the metal electrode through the conductive sintered body to support and form the overhanging structure, and the influence of the heat stress of packaging structure itself to sensor output is reduced.

Description

Technical Field

[0001] This utility model relates to a packaging structure, and more particularly to a leadless packaging structure for a pressure sensor. Background Technology

[0002] Pressure sensors convert pressure signals into electrical signals and are widely used in aerospace, industrial control, automotive engineering, and petrochemical industries. Currently, certain specialized fields are placing even stricter demands on the performance of pressure sensors; for example, pressure sensors used for pressure monitoring in aircraft engines are required to operate stably for extended periods in high-temperature environments.

[0003] Traditional leadless packaging structures utilize a metal-glass composite conductive paste to connect the chip's metal electrodes and contact pins, and use glass paste to achieve a bond between the chip, glass substrate, and housing. Direct contact between the chip and the glass substrate introduces thermal stress under high-temperature thermo-mechanical coupling. The thermal stress in the package casing and glass substrate at the bottom of the package structure also affects the chip, thereby reducing measurement accuracy. Utility Model Content

[0004] The purpose of this invention is to overcome the defects of the prior art and provide a leadless packaging structure for a pressure sensor. The sensitive chip is supported by a conductive sintered body connecting the conductive pin and the metal electrode to form a suspended structure, which reduces the impact of the thermal stress of the packaging structure itself on the sensor output.

[0005] The purpose of this utility model is achieved as follows: a leadless packaging structure for a pressure sensor includes a sensitive chip, a metal shell, an insulating base, and conductive pins. A blind hole is provided on the support layer of the sensitive chip, and multiple metal electrodes are disposed within the blind hole. The metal electrodes are connected to the conductive pins via a conductive sintered body. The sensitive chip is supported by the conductive pins and metal electrodes connected by the conductive sintered body to form a suspended structure. The insulating base connects the conductive pins below the suspended structure to the metal shell.

[0006] Furthermore, the sensitive chip is suspended above the insulating base by conductive pins at a height of 0.5mm.

[0007] To improve the high-temperature stability of the sensitive chip, the sensitive chip adopts an SOI sensitive chip, which includes a varistor layer, an insulating layer, and a support layer.

[0008] To improve the overall strength of the suspended structure, the conductive sintered body is filled into the blind holes on the support layer.

[0009] To increase the adhesion strength between the electrode and silicon, the metal electrode is a titanium-platinum composite electrode.

[0010] To better achieve the connection between the metal electrode and the conductive pin, the conductive sintered body is formed by sintering conductive silver paste.

[0011] Furthermore, the insulating base is formed by sintering glass slurry.

[0012] The present invention adopts the above technical solution, and compared with the prior art, the beneficial effects are as follows: In the present invention, the sensitive chip is connected to the conductive pin and the metal electrode support chip through the conductive sintered body to form a suspended structure, which avoids the thermal stress caused by the high temperature thermo-solid coupling after the chip comes into contact with the insulating base, and achieves the purpose of thermal stress self-release, reducing the impact of the thermal stress of the packaging structure itself on the sensor output; the use of titanium-platinum composite electrodes improves the reliability of the ohmic contact between the metal electrode and the silicon lead. Attached Figure Description

[0013] Figure 1 This is a schematic diagram of the structure of the present invention.

[0014] The components include: 1. Sensitive chip; 1-1. Varistor layer; 1-2. Insulating layer; 1-3. Support layer; 2. Metal casing; 3. Insulating base; 4. Conductive pin; 5. Conductive sintered body; and 6. Metal electrode. Detailed Implementation

[0015] like Figure 1The diagram illustrates a leadless packaging structure for a pressure sensor, comprising a sensitive chip 1, a metal housing 2, an insulating base 3, and conductive pins 4. Blind holes are provided on the support layer 1-3 of the sensitive chip 1, and multiple metal electrodes 6 are disposed within these blind holes. To improve the overall strength of the suspended structure, a conductive sintered body 5 fills the blind holes on the support layer 1-3. The metal electrodes 6 are connected to the conductive pins 4 via the conductive sintered body 5. The sensitive chip 1 is supported by the conductive pins 4 and metal electrodes 6 connected by the conductive sintered body 5 to form the suspended structure. The insulating base 3 connects the conductive pins 4 below the suspended structure to the metal housing 2. The insulating base 3 is sintered from glass paste, and the conductive pins 4 are encapsulated in the glass paste and then filled within the metal housing 2. The sensitive chip 1 is suspended above the insulating base 3 via the conductive pins 4, with a height of 0.5 mm. Sensitive chip 1 adopts an SOI sensitive chip, which includes a varistor layer 1-1, an insulating layer 1-2, and a support layer 1-3. The varistor layer 1-1 and the support layer 1-3 are silicon layers, and the insulating layer is a silicon dioxide layer, which effectively improves the high-temperature stability of the sensitive chip. The metal electrode 6 adopts a titanium-platinum composite electrode, which increases the adhesion strength between the electrode and silicon. The conductive sintered body 5 is sintered from conductive silver paste to realize the connection between the metal electrode 6 and the conductive pin 4. The conductive pin 4 and the metal shell 2 are made of Kovar alloy 4J29, which has good compatibility and process stability. The insulating base is sintered from DM305 glass, which has good insulation and impact resistance at high temperatures.

[0016] In this invention, the sensitive chip is connected to conductive pins via a conductive sintered body, forming a suspended structure with the chip's metal electrode support. This avoids the thermal stress caused by high-temperature thermo-coupling after the chip comes into contact with the insulating substrate, achieving self-releasing of thermal stress and reducing the impact of the packaging structure's own thermal stress on the sensor output. The use of titanium-platinum composite electrodes improves the reliability of the ohmic contact between the metal electrode and the silicon lead.

[0017] This utility model is not limited to the above embodiments. Based on the technical solutions disclosed in this utility model, those skilled in the art can make some substitutions and modifications to some of the technical features without creative labor, and these substitutions and modifications are all within the protection scope of this utility model.

Claims

1. A leadless packaging structure for a pressure sensor, characterized in that, The device includes a sensitive chip, a metal casing, an insulating base, and conductive pins. The support layer of the sensitive chip has blind holes, and multiple metal electrodes are disposed within the blind holes. The metal electrodes are connected to the conductive pins via conductive sintered bodies. The sensitive chip is supported by the conductive pins and metal electrodes connected by the conductive sintered bodies to form a suspended structure. The insulating base connects the conductive pins below the suspended structure to the metal casing.

2. The leadless packaging structure of a pressure sensor according to claim 1, characterized in that, The sensitive chip is suspended above the insulating base by conductive pins at a height of 0.5 mm.

3. The leadless packaging structure of a pressure sensor according to claim 2, characterized in that, The sensitive chip is an SOI sensitive chip, which includes a varistor layer, an insulating layer and a support layer.

4. The leadless packaging structure of a pressure sensor according to claim 1, characterized in that, The conductive sintered body fills the blind holes in the support layer.

5. The leadless packaging structure of a pressure sensor according to claim 1, characterized in that, The metal electrode is a titanium-platinum composite electrode.

6. The leadless packaging structure of a pressure sensor according to claim 1, characterized in that, The conductive sintered body is formed by sintering conductive silver paste.

7. The leadless packaging structure of a pressure sensor according to claim 1, characterized in that, The insulating base is made by sintering glass slurry.

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