JP2002310830A - Manufacturing method of sensor device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a manufacturing method of sensor device capable of reducing the manufacturing cost and part cost. SOLUTION: This method is characterized by abolishing the structure having a lead 30 insert molded to a sensor case 20, providing an opening part 15 in the lead 30 and a projection 16 in a desired position corresponding to the opening part 15 of the lead 30 in the sensor case 20, and fixing the lead 30 to the sensor case 20 by a thermal caulking using a caulking tool 17 as shown in c. Accordingly, the process for inspecting the connection of the sensor case 20 to the lead 30 can be eliminated, and the metal mold for molding the sensor case 20 can be simplified to reduce the manufacturing cost and part cost.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sensor device and, more particularly, to a manufacturing method for reducing the cost of parts and manufacturing cost.

[0002]

2. Description of the Related Art Conventionally, as a sensor device of this kind, a pressure sensor described in JP-A-8-54305 or JP-A-9-178591 has been proposed.

In these pressure sensors, a sensor element and a circuit board made of a semiconductor are mounted, and a connector case is attached to a sensor case in which a lead for signal extraction is insert-molded. It houses the elements and the circuit board.

[0004]

However, in the structure in which the lead is insert-molded in the sensor case as in the above-mentioned prior art, a step of inspecting a joint failure between the sensor case and the lead and a complicated mold for molding the sensor case are required. By
There is a problem that it leads to an increase in manufacturing cost and parts cost.

Accordingly, an object of the present invention is to provide a method of manufacturing a sensor device in which manufacturing costs and component costs are reduced in view of the above problems.

[0006]

According to a first aspect of the present invention, there is provided a method of manufacturing a sensor device, wherein a lead electrically connected to a sensor element is fixed on a sensor case having a sensor element disposed on one surface side. In the method of manufacturing a sensor device having a step, the lead is fixed to the sensor case by heat staking in the lead fixing step.

According to the first aspect of the present invention, the lead is fixed to the sensor case by heat caulking instead of insert molding the lead in the sensor case as in the prior art. The number of bonding inspection steps can be reduced, the mold for molding the sensor case can be simplified, and the manufacturing cost and component cost can be reduced.

According to a second aspect of the present invention, there is provided a method of manufacturing a sensor device, wherein a projection is provided at a desired position on one surface of a sensor case, and an opening is provided at a position corresponding to the projection on the lead. In the lead fixing step, the lead is fixed to the sensor case by inserting the protrusion into the opening and melting the protrusion.

According to the present invention, the lead is fixed to the sensor case by inserting the protrusion into the opening and melting the protrusion without inserting the lead into the sensor case as in the prior art. Therefore, the same effect as the first aspect can be obtained.

A method of manufacturing a sensor device according to a third aspect is characterized in that a wire bonding step of connecting a wire to the lead is performed simultaneously with the step of fixing the lead.

When the wire bonding step is performed simultaneously with the lead fixing step according to the first and second aspects, the wire can be connected to the lead by the heat of caulking (heat when the protrusion is melted). Because,
Man-hours can be reduced, and manufacturing costs can be reduced.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment in which the present invention is applied to a method of manufacturing a semiconductor pressure sensor will be described below with reference to the drawings. The semiconductor pressure sensor according to the present embodiment is attached to, for example, a water flow path in a home washing machine, and is used as a water level sensor that detects a water level by the pressure in the flow path.

FIG. 1 shows a cross-sectional structure of a main part of a semiconductor type pressure sensor 100 of this embodiment, and FIG. 2 shows a view taken in the direction of arrow A in FIG. FIG. 1 is a view showing a state in which a connector case that is assembled to the sensor case 20 and covers the sensor element 10 is omitted.

First, as shown in FIG. 1, a sensor element 10 made of a semiconductor is disposed on a semiconductor type pressure sensor 100, and a resin-molded sensor case 20 and a part thereof are exposed from the sensor case 20. As a result, the sensor element 10 is fixed to the sensor case 20 and includes a plurality of leads 30 electrically connected to the sensor element 10.

The sensor case 20 is made of, for example, a thermoplastic plastic material such as PPS (polyphenylene sulfide) or PBT (polybutylene terephthalate), and has a sensor element 10 and the like disposed on one side and a sensor element 10 on the other side. It has a protruding pressure introduction port 21.

The distal end of the pressure introduction port 21 can be attached via an O-ring (not shown) or the like. Inside the pressure introduction port 21 is a pressure introduction hole 22 for introducing pressure. Is provided.

On one surface side of the sensor case 20, there is formed a concave portion 23 recessed from the flat portion.
Inside, a sensor element 10 is fixed via a pedestal 11 made of glass or the like.

The sensor element 10 and the pedestal 11 are bonded by glass bonding or the like, and a through-hole communicating with the pressure introducing hole 22 is formed inside the pedestal 11. Pressure is transmitted to the diaphragm of the sensor element 10 through the through hole of the pedestal 11.

Further, in the recess 23, the glass pedestal 11 is provided.
In order to increase the airtightness between the through hole and the pressure introduction hole 22,
A sealant 24 made of silicon gel, resin adhesive or the like is filled.

Although not shown, the sensor element 10 is a semiconductor material having a piezoresistive effect (for example, single crystal silicon).
A plurality of diffused resistors are formed on a diaphragm made up of a plurality of diffused resistors, and these diffused resistors are bridge-connected. A change in the resistance value of the diffused resistors according to the deformation of the diaphragm is extracted as an electric signal from the bridge circuit. It has become.

The plurality of leads 30 are formed in the shape of a flat plate, and these leads 30 can be made of a general lead frame material (for example, phosphor bronze electrolytic nickel plated). .

Here, of these leads 30, three exposed portions 31 largely exposed from the outer wall of the sensor case 20 are provided.
(See FIG. 2) constitutes an extraction unit for extracting an electric signal (output) of the sensor element 10 to the outside.

As shown in FIGS. 1 and 2, a bipolar transistor element 12 as an amplifier circuit for amplifying an output signal from the sensor element 10 is provided on one surface side of the sensor case 20. A MOS transistor element 13 as an adjustment circuit for adjusting an output signal, a signal of the bipolar transistor element 12, and the like is fixed with an adhesive or the like.

The sensor element 10, the bipolar transistor element 12, and the MOS transistor element 1
3, and the leads 30 are electrically connected by a plurality of wires (shown by bold lines in the drawing) 14 made of gold, aluminum, or the like formed by wire bonding.

As a result, an electric signal (output) from the sensor element 10 passes through these wires 14 through the bipolar transistor element 12 and the MOS transistor element 1.
3, the lead 30 and the exposed portion 31 of the lead 30 are taken out to the outside.

The semiconductor pressure sensor 1 having the above structure
00 operates as follows.

First, the pressure applied to the semiconductor pressure sensor 100 is introduced from the pressure introduction hole 22 through the through hole of the pedestal 11 to the back surface of the diaphragm of the sensor element 10.

When the diaphragm is distorted by the pressure difference between the front and back surfaces of the diaphragm, an electric signal is generated based on the distortion.

The electric signal is supplied to a wire 14, a bipolar transistor element 12, a MOS transistor element 13,
The pressure is applied to the semiconductor pressure sensor 100 by being taken out to the outside through the lead 30 and the exposed portion 31 of the lead 30 and thereafter performing signal processing in an external circuit. ing.

Next, the semiconductor pressure sensor 1 of the present embodiment
00 is described with reference to FIG. FIG. 3 shows only the parts necessary for explanation.

First, as shown in FIG. 3A, the sensor element 10 is fixed in the recess 23 of the sensor case 20. At the same time, although not shown, the bipolar transistor element 12 and the MOS transistor element are also fixed to the sensor case 20. At a desired position on the surface of the sensor case 20 to which the lead 30 is fixed, a projection 16 integrally formed with the sensor case 20 is provided.

Subsequently, as shown in FIG. 3B, a lead 30 having an opening 15 at a position corresponding to the projection 16 is temporarily fixed to the sensor case 20. At this time, the protrusion 16 provided on the sensor case 20 is inserted into the opening 15 provided on the lead 30.

Subsequently, as shown in FIG. 3C, the lead 30 is connected to the sensor case 20 by using a caulking jig 17.
And heat is applied to the projections 16 provided on the sensor case 20 by the caulking jig 17. Thus, the protrusion 16 can be melted, and the lead 30 can be fixed to the sensor case 20 by the melted protrusion 16. At the same time, the heat applied by the caulking jig 17 is transmitted to the lead 30 via the projection 16, and the wire 14 is connected using the transmitted heat.

Thereafter, although not shown, the sensor case 20
The semiconductor type pressure sensor 100 is completed by joining the connector case to the semiconductor device.

As described above, in the semiconductor pressure sensor 100 of the present embodiment, the structure in which the lead 30 is insert-molded in the sensor case 20 is eliminated, and as described above, the lead 3
The lead 30 is fixed to the sensor case 20 by providing a protrusion 16 at a desired position corresponding to the opening 15 of the lead 30 in the sensor case 20 and caulking using a caulking jig 17. It is characterized by doing.

This makes it possible to reduce the number of steps for inspecting the joint between the sensor case 20 and the lead 30,
The mold for molding 0 can be simplified, and the manufacturing cost and the component cost can be reduced.

Further, in this embodiment, the caulking jig 17
Since the wires 14 are connected by utilizing the heat transmitted to the leads 30, the man-hours can be reduced, and the manufacturing cost can be reduced.

In this embodiment, the wire bonding is performed using the heat transmitted from the caulking jig. However, the present invention is also effective in a method of performing the wire bonding by ultrasonic bonding.

In the conventional structure in which the lead 30 is insert-molded in the sensor case 20, the lead 30 and the sensor case 20 are formed of different materials. The case 20 contracts, and a gap is generated between the sensor case 20 and the lead 30.

In this case, when wire bonding is performed by ultrasonic bonding, the fixing of the lead 30 to the sensor case 20 becomes insufficient due to the gap, so that ultrasonic vibration cannot be applied satisfactorily, and the bonding failure of the wire 14 is reduced. May occur.

On the other hand, in this embodiment, since the lead 30 is wire-bonded while being pressed by the caulking jig 17, even when wire bonding is performed by ultrasonic bonding, the lead 30 is securely fixed. Therefore, the ultrasonic vibration does not escape, and the bonding failure of the wire 14 can be reduced.

The present invention is not limited to the above embodiment, but can be applied to various aspects.

For example, the present invention can be applied not only to the semiconductor pressure sensor as in the present embodiment but also to other physical quantity sensors such as a semiconductor pressure acceleration sensor for detecting the acceleration of the medium to be measured.

Further, in the present embodiment, the sensor element 10 and the bipolar transistor element constitute a circuit by the MOS transistor element 13. However, the present invention is not limited to this, and it is a one-chip sensor in which the circuit is integrated. Even if there is, the same effect can be obtained.

[Brief description of the drawings]

FIG. 1 is a diagram showing a schematic cross-sectional structure of a sensor case of a semiconductor pressure sensor according to an embodiment of the present invention.

FIG. 2 is a diagram showing a schematic plan structure of a sensor case of the semiconductor pressure sensor according to the embodiment of the present invention. FIG. 2 is a view taken in the direction of the arrow A in FIG.

FIG. 3 is a diagram illustrating a method of assembling the semiconductor pressure sensor according to the embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 ... Sensor element, 11 ... Pedestal, 12 ... Bipolar transistor element, 13 ... MOS transistor element, 14 ... Wire, 15 ... Opening, 16 ... Projection, 17 ... Caulking jig, 20 ... Sensor case, 21 ... Pressure introduction port Reference numeral 22: pressure introducing hole 23: concave portion 24: sealant 30: lead, 31: exposed portion of the lead 100: semiconductor type pressure sensor

Continued on the front page F term (reference) 2F055 AA39 BB19 CC02 DD05 EE14 FF43 GG01 GG12 4M112 AA01 BA01 CA08 CA13 CA15 GA01

Claims (3)

[Claims] 1. A method for manufacturing a sensor device, comprising: fixing a lead electrically connected to the sensor element on a sensor case having a sensor element disposed on one surface side. A method of manufacturing a sensor device, wherein the lead is fixed to the sensor case by heat caulking. 2. The sensor device according to claim 1, wherein a projection is provided at a desired position on one surface side of the sensor case, and an opening is provided at a position corresponding to the projection on the lead. 2. The lead fixing step, wherein the lead is fixed to the sensor case by inserting the protrusion into the opening and melting the protrusion.
3. The method for manufacturing a sensor device according to claim 1. 3. The method according to claim 1, wherein a wire bonding step of connecting a wire to the lead is performed simultaneously with the step of fixing the lead.