KR101628267B1 - Pressure sensor - Google Patents

Abstract

A pressure sensor is initiated. The pressure sensor includes a flexible substrate electrically connected to the sensor element and the sensor element. The flexible board includes a terminal connection portion connected to the connector terminal, a drive chip mounting portion on which the drive chip is mounted, and an electrode pattern formed on at least one surface of the flexible substrate and electrically connected to the sensor element. The sensor element includes a connection terminal portion electrically connected to the electrode pattern of the flexible substrate.

Description

Pressure sensor

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pressure sensor, and more particularly to a technique related to electrical connection between a sensor element constituting a pressure sensor and a circuit board.

Pressure sensors are devices that measure absolute or relative pressures, and capacitive, piezoelectric, and piezoresistive types are well known. For reference, Korean Patent Publication No. 10-1013186 discloses a pressure sensor in which a pressure sensor chip made of a silicon material is stably attached to an integral base of a metal material.

Korean Patent Registration No. 10-1013186 (Jan. 28, 2011)

The proposed invention aims to improve the electrical connection structure of the pressure sensor.

According to an aspect, a pressure sensor includes a flexible substrate electrically connected to a sensor element and a sensor element. The flexible board includes a terminal connection portion connected to the connector terminal, a drive chip mounting portion on which the drive chip is mounted, and an electrode pattern formed on at least one surface of the flexible substrate and electrically connected to the sensor element. The sensor element includes a connection terminal portion electrically connected to the electrode pattern of the flexible substrate.

According to an aspect of the present invention, the connection terminal portion of the sensor element includes a via hole electrically connected to a pressure sensing electrode pattern for sensing pressure, which is filled with a conductive material, and a via hole formed in contact with the via hole on the surface of the sensor element, And a surface electrode pattern electrically connected to the pattern.

According to one aspect, the electrode patterns of the flexible substrate are formed on both sides of the substrate and are electrically connected to each other.

According to one aspect, the flexible substrate further includes a grounding piece extending from the substrate to contact and electrically ground the housing.

In the proposed invention, a driving chip is mounted on a flexible substrate, and is electrically connected to a connector and a sensor element. Therefore, a separate substrate for driving chip mounting is not required, and the flexible substrate is directly soldered to the sensor element, thereby reducing the number of solder pieces.

In addition, it has a structure that enables soldering by heat welding or the like instead of conventional wire brazing which is difficult and requires manual work.

1 is a perspective view of a pressure sensor according to an embodiment.
2 is a cross-sectional view of a pressure sensor according to an embodiment.
3 is an exploded perspective view of a pressure sensor according to an embodiment.
4 is a plan view of a flexible substrate according to one embodiment.
5 is a top view of a sensor element according to one embodiment.
6 is a cross-sectional view of a sensor element according to one embodiment.
7 is a plan view of a sensor element in which a flexible substrate and a flexible substrate are electrically connected according to an embodiment.
8 is a plan view of a flexible substrate according to another embodiment.

BRIEF DESCRIPTION OF THE DRAWINGS The foregoing and further aspects of the present invention will become more apparent from the following detailed description of preferred embodiments with reference to the accompanying drawings. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 is a perspective view of a pressure sensor according to an embodiment, FIG. 2 is a cross-sectional view of a pressure sensor according to an embodiment, and FIG. 3 is an exploded perspective view of a pressure sensor according to an embodiment. The pressure sensor includes a connector (100) and a housing (200). The connector 100 is assembled to the housing 200 and can be manufactured by insert molding a synthetic resin material such as polybutylene terephthalate (PBT). The connector 100 is provided with a plurality of terminals 110. The terminals 110 are electrically connected to a flexible printed circuit board (FPCB) 300.

The flexible substrate 300 is electrically connected to the terminals 110 of the upper connector 100 and the sensor element 400 located below. As shown in FIGS. 2 and 3, the flexible substrate 300 may be curved. A driving chip is mounted on the flexible substrate 300. Since the driving chip is mounted on the flexible substrate 300, a separate circuit board is not required.

The sensor element 400 may be a piezoelectric resistance type, a capacitance type, or the like. In the case of the piezo-resistive type, the sensor element 400 generates a micro-resistance change by a wheatstone bridge composed of four strain gages and converts it into an electric signal. In the case of the capacitance type, the change in capacitance caused by the pressure is converted into an electric signal. The sensor element 400 is electrically connected to the flexible substrate 300. According to one aspect, an electrode pattern for electrical connection with the flexible substrate 300 is provided on the surface of the sensor element 400.

4 is a plan view of a flexible substrate according to one embodiment. 4, the flexible substrate 300 includes a plurality of terminal holes 310, a driving chip mounting portion 320, and an electrode pattern 330. The terminals 110 of the connector 100 are inserted into the terminal holes 310 and the terminals 110 of the inserted connector 100 are electrically connected to the flexible substrate 300. A driving chip is mounted on the driving chip mounting portion 320. The driving chip computes and amplifies a signal transmitted from the sensor element 400 and transmits the amplified signal to an external electronic device through the connector 100. The electrode pattern 330 is formed on one end of the flexible substrate 300. The electrode pattern 330 may be formed only on one side or vertically on both sides. When formed on both sides, the electrode patterns 330 on both sides are electrically connected to each other. For example, through the inside of the flexible substrate 300 and electrically connected thereto.

FIG. 5 is a plan view of a sensor element according to one embodiment, and FIG. 6 is a cross-sectional view of a sensor element according to an embodiment. The sensor element 400 includes a connection terminal portion that is electrically connected to the electrode pattern 330 of the flexible substrate 300. According to an aspect, the connection terminal portion may include via holes 410 and a surface electrode pattern 420. This is explained in detail. The sensor element 400 includes via holes 410. The via holes 410 are filled with the conductive material 430 (ex, epoxy), and the conductive material is electrically connected to the electrode pattern (not shown) for pressure sensing of the membrane, Lt; / RTI > A surface electrode pattern 420 is formed on the surface of the sensor element 400 so as to be in contact with the via hole 410 and electrically connected to the electrode pattern of the flexible substrate 300. In one embodiment, the surface electrode pattern 420 is formed through paste patterning with a silk screen technique. When the surface electrode pattern 420 is formed by the paste patterning using the silk screen technique, the paste flows down to the via hole 410 in the process of forming the surface electrode pattern 420. The conductive material filling the via hole 410, .

7 is a plan view of a sensor element in which a flexible substrate and a flexible substrate are electrically connected according to an embodiment. The electrode pattern 330 of the flexible substrate 300 and the surface electrode pattern 420 of the sensor element 400 are physically contacted through soldering. In one embodiment, the electrode pattern 330 of the flexible substrate 300 and the surface electrode pattern 420 of the sensor element may be soldered through a hot bar. Generally, the material of the sensor element is ceramic. Since ceramics dissipate heat, it is difficult to bond with a general soldering method. Accordingly, the electrode pattern 330 of the flexible substrate 300 and the surface electrode pattern 420 of the sensor element are adhered to each other through hot bar welding. 7, even if the electrode pattern formed on the upper surface of the flexible substrate 300 is not brought into contact with the surface electrode pattern 420 of the sensor element 400, the electrode pattern formed on the lower surface of the flexible substrate 300, The surface electrode pattern 420 of the element 400 is contacted, so that the electrical connection between the flexible substrate 300 and the sensor element 400 is assured. This is because the electrode pattern formed on the upper surface of the flexible substrate 300 and the electrode pattern formed on the lower surface are electrically connected to each other.

8 is a plan view of a flexible substrate according to another embodiment. The basic structure is the same as in Fig. However, the flexible board 300 shown in FIG. 8 may further include a grounding piece 340 that extends from the board and electrically connects the flexible board 300 to the housing 200 as it contacts the housing 200. The grounding piece 340 may be more than two. The grounding piece 340 is electrically connected to the housing 200 made of a metal material and is grounded, thereby preventing malfunction of the pressure sensor due to electromagnetic interference (EMI).

The present invention has been described with reference to the preferred embodiments. It will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims. Therefore, the disclosed embodiments should be considered in an illustrative rather than a restrictive sense. The scope of the present invention is defined by the appended claims rather than by the foregoing description, and all differences within the scope of equivalents thereof should be construed as being included in the present invention.

100: connector 110: terminal
200: housing 300: soft substrate
310: terminal hole 320: driving chip mounting part
330: electrode pattern 340: grounding piece
400: sensor element 410: via hole
420: surface electrode pattern 430: conductive material

Claims (4)

delete A flexible board including a terminal connection portion connected to a connector terminal, a drive chip mounting portion on which the drive chip is mounted, and an electrode pattern formed on at least one surface of the flexible substrate; And
A sensor element including a pressure sensing electrode pattern for sensing the pressure of the membrane and a connection terminal portion for electrically connecting the electrode pattern of the flexible substrate to the pressure sensing electrode pattern,
The connection terminal portion of the sensor element is:
A via hole filled with a conductive material and electrically connected to the pressure sensing electrode pattern; And
A surface electrode pattern formed to abut the via hole on the surface of the sensor element and being electrically connected to the electrode pattern of the flexible substrate;
.
3. The method of claim 2,
Wherein the electrode pattern of the flexible substrate is formed on both sides of the substrate and is electrically connected to each other.
The flexible substrate according to claim 2, wherein the flexible substrate comprises:
Further comprising a grounding piece extending from the substrate and contacting the housing to electrically ground it.

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