阅读说明：本技术 一种mems封装结构及其制造方法 (MEMS packaging structure and manufacturing method thereof ) 是由 张利松 陈雷 衡文举 沈国强 于 2021-09-08 设计创作，主要内容包括：本发明公开了一种MEMS封装结构及其制造方法,属于集成电路封装技术领域。其压力接头本体的中央开设上下贯通的压力进入通道(1-1),所述压力进入通道(1-1)的出口设置压力分散口(1-2),所述压力分散口(1-2)包括若干对倒置的Y型分散口,所述压力传感器芯片(6)通过粘结胶(7)黏贴在基座(4)的基台(4-3)中央,基座(4)向上与转接头(2)固连,并将压力敏感膜片(3)固定在基座(4)与转接头(2)之间。本发明提出的接头结构采用型分散口实现压力分流,设置压力分流通道,可以有效避免压力对MEMS芯片的正面冲击。(The invention discloses an MEMS (micro-electromechanical system) packaging structure and a manufacturing method thereof, belonging to the technical field of integrated circuit packaging. The central authorities of its pressure joint body set up pressure entering passageway (1-1) that link up from top to bottom, the export of pressure entering passageway (1-1) sets up pressure dispersion mouth (1-2), pressure dispersion mouth (1-2) include a plurality of Y type dispersion mouths to the inversion, pressure sensor chip (6) are pasted in base station (4-3) central authorities of base (4) through bonding glue (7), and base (4) upwards links firmly with adapter (2) to fix pressure sensitive diaphragm (3) between base (4) and adapter (2). The joint structure provided by the invention adopts the type dispersing port to realize pressure shunting, and the pressure shunting channel is arranged, so that the front impact of pressure on the MEMS chip can be effectively avoided.)

1. An MEMS packaging structure is characterized by sequentially comprising a pressure joint (1), an adapter (2), a pressure sensitive membrane (3), a metal wire (5), a base (4), metal pins (4-5) and a pressure sensor chip (6) from top to bottom,

the pressure joint (1) comprises a pressure joint body and a connector (1-3), the center of the upper end of the pressure joint body is provided with a pressure inlet channel (1-1) which is communicated up and down, the outlet of the pressure inlet channel (1-1) is provided with a pressure dispersion port (1-2), the pressure dispersion port (1-2) comprises a plurality of pairs of inverted Y-shaped dispersion ports, and the connector (1-3) protrudes out of the side of the lower end of the pressure joint body;

the adapter (2) comprises an adapter body, an adapter front interface (2-1), an adapter rear interface (2-2) and a through hole I (2-3), wherein the through hole I (2-3) is formed in the center of the adapter body, the adapter front interface (2-1) is arranged on the outer side of the upper end of the adapter body, and the adapter rear interface (2-2) is arranged on the inner side of the lower end of the adapter body;

a base table (4-3) is arranged in the center of the base table (4), a plurality of terminals (4-2) extending outwards are arranged on the outer edge of the base table (4-3) to form an MEMS pressure sensor detection cavity, a through hole II (4-7) is formed in the middle end of each terminal (4-2), the metal pin (4-5) penetrates through the through hole II (4-7), and the upper end of the metal pin (4-5) is fixedly connected with the terminal (4-2) of the base table (4) through glass sinter (4-1);

the pressure sensor chip (6) is adhered to the center of a base table (4-3) of the base (4) through an adhesive (7), and the pressure sensor chip (6) is electrically connected with the metal pins (4-5) through metal wires (5);

the terminal (4-2) of the base (4) and the edge of the pressure sensitive membrane (3) are aligned with the adapter rear interface (2-2) of the adapter (2), the base (4) is upwards fixedly connected with the adapter (2), and the pressure sensitive membrane (3) is fixed between the base (4) and the adapter (2);

the front adapter interface (2-1) of the adapter (2) is clamped into the interface (1-3) of the pressure joint (1) and is fixedly connected.

2. The MEMS package structure of claim 1, wherein the pressure dispersion port (1-2) is a pair of inverted Y-shaped dispersion ports.

3. The MEMS package structure of claim 1, wherein the pressure inlet channel (1-1) is located directly above the via i (2-3).

4. The MEMS package structure of claim 1, wherein the pressure sensor die (6) is located directly below the via i (2-3).

5. The MEMS packaging structure according to claim 1, wherein the lower end of the metal pin (4-5) is extended downward beyond the bottom of the submount (4-3).

6. A manufacturing method of an MEMS packaging structure comprises the following processes:

step one, taking raw materials of a pressure joint body with a proper size, machining a symmetrical step shape by using a lathe, and reserving enough size;

step two, processing a pressure dispersion port (1-2) of the pressure joint body, and specifically comprises the following steps:

step 2.1, horizontally clamping the upper end of the pressure joint body by using a clamp, horizontally adjusting a drill bit of a lathe to be aligned with an axisymmetric center line of the pressure joint body, enabling the pressure joint body to arbitrarily deviate at an angle of alpha =45 degrees, horizontally feeding the drill bit, stopping until the axisymmetric center line of the pressure joint body, withdrawing the drill bit, forming a first pressure dispersion port (1-2) of a Y-shaped hole pointing to the center of the pressure joint body in an oblique upward direction, and returning the clamp;

step 2.2, the pressure joint body rotates in the circumferential direction by an angle beta, and the step 2.1 is repeated to complete a second pressure dispersion port (1-2) of the Y-shaped hole;

step 2.3, repeating the step 2.1 and the step 2.2, and uniformly finishing all drilling holes;

step three, replacing a drill bit of the lathe with a milling cutter, milling useless parts in interfaces (1-3) at the lower end of the pressure joint body from the axisymmetric center line of the pressure joint body outwards, and retracting the cutter;

clamping the lower end of the pressure joint body by using a clamp, leveling, changing a drill bit with one code for a lathe, horizontally feeding the drill bit of the lathe along the axisymmetric center line of the pressure joint body, directly abutting against the deep part of the pressure dispersion port (1-2), opening all the pressure dispersion ports (1-2) to form a pressure inlet channel (1-1), and retracting the drill bit;

checking and polishing the whole pressure joint (1), removing burrs and finishing the manufacture of the pressure joint (1);

step six, taking an adapter (2), clamping an adapter front interface (2-1) of the adapter (2) into an interface of a pressure joint (1) and fixedly connecting the adapter front interface and the pressure joint together by using a welding method;

step seven, taking a base (4), forming a through hole II (4-7) in the middle end of a terminal (4-2) of the base (4), enabling a metal pin (4-5) to penetrate through the through hole II (4-7), and fixedly connecting the upper end of the metal pin (4-5) with the base (4) through a glass sinter (4-1) through a glass sintering process;

step eight, taking a pressure sensor chip (6), sticking the pressure sensor chip (6) to the center of a base table (4-3) of a base (4) through an adhesive (7), fixedly connecting the pressure sensor chip (6) with one end of a metal wire (5) through a welding flux, and fixedly connecting the other end of the metal wire (5) with a metal pin (4-5) on the base (4) through the welding flux;

aligning the terminal (4-2) of the base (4) and the edge of the pressure sensitive membrane (3) with the rear adapter interface (2-2) of the adapter (2), upwards fixing the base (4) and the adapter (2) together by using a welding method, and fixing the pressure sensitive membrane (3) between the base (4) and the adapter (2).

7. The method of manufacturing of claim 6, wherein the angle β over which the pressure fitting body is rotated circumferentially uniformly is calculated as follows:

if the dispersion openings (1-2) are a pair, the angle beta is rotated by 180 degrees;

if the two dispersion openings (1-2) are provided, the angle beta rotates by 90 degrees each time;

if the dispersion openings (1-2) are three pairs, the angle beta rotates by 60 degrees each time; and so on.

8. The manufacturing method according to claim 6, characterized in that in step three, the milling cutter is fed to a depth half of the depth of the interface (1-3) of the lower end of the joint body.

9. The manufacturing method according to claim 6, wherein in the sixth step, the welding method is argon arc welding, laser welding or electron beam welding.

10. The manufacturing method according to claim 6, wherein in the ninth step, the welding method is argon arc welding, laser welding or electron beam welding.

Technical Field

The invention relates to an MEMS (micro-electromechanical system) packaging structure and a manufacturing method thereof, belonging to the technical field of integrated circuit packaging.

Background

The fluid pressure sensor internally uses a pressure sensor chip processed based on silicon-based MEMS technology, called a MEMS pressure sensor chip. In the fluid pressure sensor, when fluid pressure acts on an MEMS pressure sensor chip, a pressure sensitive diaphragm is caused to deform, and a piezoresistor on the pressure sensitive diaphragm generates resistance change due to a piezoresistive effect, so that a Wheatstone bridge consisting of the piezoresistors in a pressure sensing element generates an electric signal to be output, and the conversion from a pressure signal to an electric signal is realized.

Among the prior art, fluid pressure sensor contains the sampling tube and the casing base of being connected with the sampling tube cooperation, in the casing base, is provided with MEMS pressure sensor chip and calibration chip, and MEMS pressure sensor chip and calibration chip separately set up in the casing base, consequently it is great to occupy the space of sensor, and material cost is high, and production cycle is long, and welding produces stress and often causes the drift of product output.

Disclosure of Invention

The invention aims to overcome the defects in the prior art and provides an MEMS packaging structure of a pressure joint structure integrally designed by adopting a pressure joint and a manufacturing method thereof.

The technical scheme of the invention is as follows:

the invention provides an MEMS packaging structure, which sequentially comprises a pressure joint, an adapter, a pressure sensitive membrane, a metal wire, a base, a metal pin and a pressure sensor chip from top to bottom,

the pressure joint comprises a pressure joint body and a connector, wherein a pressure inlet channel which is communicated up and down is formed in the center of the upper end of the pressure joint body, a pressure dispersing port is formed in an outlet of the pressure inlet channel, the pressure dispersing port comprises a plurality of pairs of inverted Y-shaped dispersing ports, and the connector protrudes out of the side of the lower end of the pressure joint body;

the adapter comprises an adapter body, an adapter front interface, an adapter rear interface and a through hole I, wherein the through hole I is formed in the center of the adapter body;

the center of the base is provided with a base table, the outer edge of the base table is provided with a plurality of terminals extending outwards to form an MEMS pressure sensor detection cavity, the middle end of each terminal is provided with a through hole II, a metal pin penetrates through the through hole II, and the upper end of the metal pin is fixedly connected with the terminal of the base through glass sinter;

the pressure sensor chip is adhered to the center of the base platform of the base through adhesive glue, and is electrically connected with the metal pins through metal wires;

aligning the terminal of the base and the edge of the pressure sensitive membrane with a rear adapter interface of the adapter, fixedly connecting the base upwards with the adapter, and fixing the pressure sensitive membrane between the base and the adapter;

and the front interface of the adapter is clamped into the interface of the pressure joint and is fixedly connected with the interface.

Optionally, the pressure dispersion port is a pair of inverted Y-shaped dispersion ports.

Optionally, the pressure inlet channel is located directly above the through hole i.

Optionally, the pressure sensor chip is located directly below the through hole i.

Optionally, the lower end of the metal pin extends downwards beyond the bottom of the base.

The invention also provides a manufacturing method of the MEMS packaging structure, which comprises the following processes:

step one, taking raw materials of a pressure joint body with a proper size, machining a symmetrical step shape by using a lathe, and reserving enough size;

step two, processing a pressure dispersion port of the pressure joint body, and specifically comprising the following steps:

step 2.1, horizontally clamping the upper end of the pressure joint body by using a clamp, horizontally adjusting a drill bit of a lathe to be aligned with an axisymmetric center line of the pressure joint body, enabling the pressure joint body to arbitrarily deviate at an angle of alpha =45 degrees, horizontally feeding the drill bit, stopping until the axisymmetric center line of the pressure joint body, withdrawing the drill bit, forming a first pressure dispersion port of a Y-shaped hole pointing to the center of the pressure joint body in an oblique upward direction, and returning the clamp;

step 2.2, the pressure joint body rotates in the circumferential direction by an angle beta, and the step 2.1 is repeated to complete a second pressure dispersion port of the Y-shaped hole;

step 2.3, repeating the step 2.1 and the step 2.2, and uniformly finishing all drilling holes;

step three, replacing a drill bit of the lathe with a milling cutter, milling useless parts in an interface at the lower end of the pressure joint body from the axisymmetric center line of the pressure joint body to the outside, and collecting cutters;

clamping the lower end of the pressure joint body by using a clamp, leveling, changing a drill bit for one yard by using a lathe, horizontally feeding the drill bit of the lathe along the axisymmetric center line of the pressure joint body, directly abutting against the deep part of the pressure dispersion port, opening all the pressure dispersion ports to form a pressure inlet channel, and retracting the cutter;

checking and polishing the whole pressure joint, removing burrs and finishing the manufacturing of the pressure joint;

step six, taking a adapter, clamping a front interface of the adapter into an interface of the pressure joint and fixedly connecting the front interface of the adapter and the interface of the pressure joint by using a welding method;

step seven, taking a base, forming a through hole II in the middle end of a terminal of the base, penetrating a metal pin through the through hole II, and fixedly connecting the upper end of the metal pin with the base through a glass sinter by a glass sintering process;

step eight, taking a pressure sensor chip, sticking the pressure sensor chip to the center of a base table of the base through bonding glue, fixedly connecting the pressure sensor chip with one end of the metal wire through a welding flux, and fixedly connecting the other end of the metal wire with the metal pin on the base through the welding flux;

aligning the terminal of the base and the edge of the pressure sensitive membrane with a rear interface of the adapter, upwards fixedly connecting the base and the adapter together by using a welding method, and fixing the pressure sensitive membrane between the base and the adapter.

Optionally, the angle β that the pressure joint body uniformly rotates circumferentially is calculated as follows:

if the dispersion openings are a pair, the angle beta is rotated by 180 degrees;

if the two pairs of dispersion openings are provided, the angle beta is rotated by 90 degrees each time;

if the dispersion openings are three pairs, the angle beta rotates by 60 degrees each time; and so on.

Optionally, in step three, the depth of the milling cutter is half of the depth of the interface of the lower end of the joint body.

Optionally, in the sixth step, the welding method is argon arc welding, laser welding or electron beam welding.

Optionally, in step nine, the welding method is argon arc welding, laser welding or electron beam welding.

Advantageous effects

1. The pressure joint in the MEMS packaging adopts the Y-shaped pressure dispersing port, pressure entering the channel is divided through the Y-shaped pressure dispersing port, so that the front impact of the pressure on the MEMS chip can be effectively avoided, the pressure inlet is communicated with the detected space and the pressure sensor chip, the MEMS chip (namely the pressure sensor chip) is contacted with a pressure source, the structure is simplified, the production period and the cost are reduced, and the material cost is reduced by about 50%;

2. the pressure joint and the adapter as well as the adapter and the base are fixedly connected, so that one-time welding is reduced, and negative effects of stress generated in the welding process on the pressure sensor chip are avoided.

Drawings

FIG. 1 is a cross-sectional view of a reduced-weld pressure joint configuration of the present invention;

FIG. 2 is a state diagram of the use of FIG. 1;

FIGS. 3A-3I are schematic flow diagrams of the forming method of FIG. 1;

in the figure:

pressure joint 1

Pressure inlet port 1-1

Pressure dispersion port 1-2

Interfaces 1-3

Adapter 2

Front interface 2-1 of adapter

Adapter rear interface 2-2

Through hole I2-3

Pressure sensitive diaphragm 3

Base 4

Glass frit 4-1

Metal pin 4-2

Base station 4-3

Through holes II 4-7

Metal wire 5

Pressure sensor chip 6

Adhesive glue 7

Circuit board 8

Component 8-1 on a circuit board

Connecting via 8-2.

Detailed Description

The following detailed description of embodiments of the invention refers to the accompanying drawings. Spatially relative terms (such as "below …", "below", "lower", "above …", "upper", and the like) may be used for ease of illustration to describe one element or component's relationship to another element or component as illustrated in the figures. Spatially relative terms may also encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. The device may be otherwise oriented 90 degrees or at other orientations and the spatially relative descriptors used herein interpreted accordingly.

As shown in fig. 1, the MEMS package structure of the present invention sequentially includes, from top to bottom, a pressure connector 1, an adapter 2, a pressure sensitive membrane 3, a metal wire 5, a base 4, metal pins 4-5, and a pressure sensor chip 6.

The pressure joint 1 comprises a pressure joint body and a connector 1-3, wherein a pressure inlet channel 1-1 which is through up and down is formed in the center of the upper end of the pressure joint body, a pressure dispersing port 1-2 is formed in an outlet of the pressure inlet channel 1-1, the pressure dispersing port 1-2 comprises a plurality of pairs of inverted Y-shaped dispersing ports, one pair of inverted Y-shaped dispersing ports are shown in the figure, and two, three or four pairs of inverted Y-shaped dispersing ports can be arranged in the figure. The interfaces 1-3 protrude out of the side of the lower end of the pressure joint body.

The adapter 2 comprises an adapter body, an adapter front interface 2-1, an adapter rear interface 2-2 and a through hole I2-3, wherein the through hole I2-3 is formed in the center of the adapter body and located under the pressure inlet channel 1-1. The front adapter interface 2-1 is arranged on the outer side of the upper end of the adapter body, and the rear adapter interface 2-2 is arranged on the inner side of the lower end of the adapter body;

the center of the base 4 is provided with a base table 4-3, the side face of the base is provided with a plurality of terminals 4-2 which extend outwards to form an MEMS pressure sensor detection cavity, the middle end of each terminal 4-2 is provided with a through hole II 4-7, a metal pin 4-5 penetrates through the through hole II 4-7, and the upper end of the metal pin 4-5 is fixedly connected with the terminal 4-2 of the base 4 through glass sinter 4-1.

The pressure sensor chip 6 is adhered to the center of the base platform 4-3 of the base 4 through the adhesive 7 and is positioned right below the pressure sensitive membrane 3. The pressure sensor chip 6 is electrically connected with the metal pins 4-5 through the metal wire 5, and the metal wire 5 enables the pressure chip 5 to communicate with the outside world and is used for inputting voltage and outputting signals.

The edge of the terminal 4-2 of the base 4 and the edge of the pressure sensitive membrane 3 are aligned with the adapter rear interface 2-2 of the adapter 2, the base 4 is upwards welded with the adapter 2 through argon arc welding (or laser welding or electron beam welding) to be fixedly connected together, and the pressure sensitive membrane 3 is fixed between the base 4 and the adapter 2. The channel 1-1 of the pressure joint 1 and the pressure dispersion port 1-2 arranged at the outlet of the channel enable pressure to be communicated with the detected space and the pressure sensor chip 6 for testing, so that the pressure sensor chip 6 is in contact with a pressure source, and the structure is simplified.

And a front adapter interface 2-1 of the adapter 2 is clamped into an interface of the pressure joint 1 and is welded together and fixedly connected by argon arc welding (or laser welding or electron beam welding).

When the circuit board is used, the lower ends of the metal pins 4-5 of the base 4 are connected into the connecting through holes II 8-2 of the circuit board through soldering. And the circuit board 8 is provided with elements 8-1 such as a capacitor and a resistor and the like, and is used for balancing a bridge circuit on the circuit board 8.

Fig. 3A to 3I are schematic flow diagrams of the forming and manufacturing method of fig. 1, and the process thereof is as follows:

step one, as shown in fig. 3A, taking raw materials of a pressure joint body with a proper size, machining a symmetrical step shape by using a lathe, and reserving enough size;

step two, processing a pressure dispersion port 1-2 of the pressure joint body, and specifically comprising the following steps:

1) horizontally clamping the upper end of the pressure joint body by using a clamp, horizontally adjusting a drill of a lathe to be aligned with an axisymmetric center line of the pressure joint body, enabling the pressure joint body to randomly deviate by an angle of alpha =45 degrees, horizontally feeding the drill until the axisymmetric center line of the pressure joint body stops, withdrawing the drill to form a first pressure dispersion port 1-2 of a Y-shaped hole which points to the center of the pressure joint body in an inclined upward direction, and returning the clamp to the original position as shown in fig. 3B;

2) the pressure connector body rotates circumferentially by an angle beta, the step 1) is repeated, and a second pressure dispersion port 1-2 of the Y-shaped hole is completed, as shown in FIG. 3C;

3) repeating the step 1) and the step 2) to finish all drilling;

to evenly distribute the drill holes, the angle β that the pressure connector body circumferentially turns through is calculated as follows:

if the dispersing openings 1-2 are a pair, the angle beta is rotated by 180 degrees;

if the two dispersion openings 1-2 are provided, the angle beta is rotated by 90 degrees each time;

if the dispersion openings 1-2 are three pairs, the angle beta rotates by 60 degrees each time; and so on.

Step three, replacing a drill bit of the lathe with a milling cutter, milling useless parts in the interface 1-3 at the lower end of the pressure joint body from the axisymmetric center line of the pressure joint body outwards, wherein the depth of feed of the milling cutter is half of the depth of the interface 1-3 at the lower end of the joint body, and retracting the cutter, as shown in fig. 3D;

clamping the lower end of the pressure joint body by using a clamp, leveling, changing a drill bit with one code for a lathe, horizontally feeding the drill bit of the lathe along the axisymmetric center line of the pressure joint body, directly abutting against the deep part of the pressure dispersion port 1-2, opening all the pressure dispersion ports 1-2 to form a pressure inlet channel 1-1, and retracting the cutter, wherein the position is shown in figure 3E;

fifthly, checking and polishing the whole pressure joint 1, removing burrs and finishing the manufacture of the pressure joint 1;

step six, taking a adapter 2, clamping a front adapter interface 2-1 of the adapter 2 into an interface of a pressure joint 1, and fixedly connecting the front adapter interface and the interface together by argon arc welding, laser welding or electron beam welding, as shown in fig. 3F;

step seven, taking a base 4, forming a through hole II 4-7 at the middle end of a terminal 4-2 of the base 4, enabling a metal pin 4-5 to penetrate through the through hole II 4-7, and fixedly connecting the upper end of the metal pin 4-5 with the base 4 through a glass sinter 4-1 by a glass sintering process, as shown in FIG. 3G;

step eight, taking a pressure sensor chip 6, adhering the pressure sensor chip 6 to the center of a base table 4-3 of a base 4 through an adhesive 7, fixedly connecting the pressure sensor chip 6 and one end of a metal wire 5 through a welding flux, and fixedly connecting the other end of the metal wire 5 and a metal pin 4-5 on the base 4 through the welding flux, as shown in fig. 3H;

ninthly, aligning the terminal 4-2 of the base 4 and the edge of the pressure sensitive membrane 3 with the rear adapter interface 2-2 of the adapter 2, fixedly connecting the base 4 and the adapter 2 upwards by argon arc welding, laser welding or electron beam welding, and fixing the pressure sensitive membrane 3 between the base 4 and the adapter 2, as shown in fig. 3I. The channel 1-1 of the pressure joint 1 and the pressure dispersion port 1-2 arranged at the outlet of the channel enable pressure to be communicated with the detected space and the pressure sensor chip 6 for testing, so that the pressure sensor chip 6 is in direct contact with a pressure source, and the structure is simplified.

The above-mentioned embodiments are intended to explain the objects, technical solutions and advantages of the present invention in further detail, and it should be understood that the above-mentioned embodiments are only exemplary embodiments of the present invention, and are not intended to limit the scope of the present invention. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.