JP2009212306A - Electronic circuit device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electronic circuit device capable of preventing a liquid resin as a sealing member from leaking from a contact part between a case body for storing an electronic circuit part and a cover member and dripping onto the outer surface of the case body. <P>SOLUTION: A catching groove 34 is formed on the outer surface of the cover 30, which is extended upward from the outer side end part 502 of the contact part 50 between a case 20 and the cover 30, guides the liquid resin 41 upward which passes the contact part 50 and leaks outward, and catches the resin. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an electronic circuit device in which an electronic circuit unit housed in a housing space formed by a case body and a cover member is sealed with a sealing resin.

As a prior art, there is an electronic circuit device disclosed in Patent Document 1 below. In this electronic circuit device, the electronic circuit unit housed in the case is sealed with a sealing resin to protect the electronic circuit unit.
JP 2002-343907 A

  However, the space for storing the electronic circuit portion is configured by the case body and the cover member that closes the opening of the case body, and the liquid resin that serves as the sealing member is disposed at the inner peripheral end (contact surface) of the boundary surface between the case body and the cover member. In the case of filling from above the inner end portion of the case, there is a problem that the liquid resin may leak from the contact portion between the case body and the cover member to the outside and hang down on the outer surface of the case body.

  The present invention has been made in view of the above points, and the liquid resin serving as a sealing member leaks from the contact portion between the case body housing the electronic circuit portion and the cover member, and hangs on the outer surface of the case body. An object of the present invention is to provide an electronic circuit device that can be prevented.

In order to achieve the above object, in the invention described in claim 1,
An electronic circuit part forming an electronic circuit;
A case body that houses the electronic circuit section;
A cover member that closes the opening of the case body;
A liquid resin filled in the case body is cured, and includes a sealing member for sealing the electronic circuit part,
The electronic circuit device in which the upper surface when the sealing member is filled in a liquid resin state is above the inner end of the contact portion where the case body and the cover member contact each other,
A collecting groove for collecting the liquid resin that has passed through the contact portion is formed on the outer surface of the cover member.

  According to this, the liquid resin that has leaked outside through the contact portion between the case body and the cover member is collected by the collection groove formed on the outer surface of the cover member, and is prevented from dripping on the outer surface of the case body. can do.

  Further, the invention described in claim 2 is characterized in that the collecting groove extends upward from an outer end portion of a contact portion between the case body and the cover member.

  According to this, the collection groove guides the leaked liquid resin upward, and the collection force in the direction of pulling up the liquid resin by the collection groove and the weight of the liquid resin in the collection groove are balanced. Since collection can be terminated, it is possible to suppress the collection force of the collection groove from promoting leakage of the liquid resin.

  According to a third aspect of the present invention, the collecting groove has a rectangular cross-sectional shape.

  According to this, the collection volume which can be collected can be ensured reliably while exhibiting the collection force of the collection groove due to the cross-sectional shape having the corners.

  According to a fourth aspect of the present invention, the electronic circuit part has a sensor part exposed on the outer surface of the case body.

  According to this, it is possible to prevent the liquid resin from leaking to the outside and dripping on the outer surface of the case body and adhere to the sensor part exposed on the outer surface of the case body.

  When the sensor unit performs at least one of transmission and reception of ultrasonic waves as in the invention described in claim 5, if the resin adheres to the sensor unit, the ultrasonic vibration is inhibited and functions. There is a possibility that it will be defective, and the effect of preventing the resin from adhering to the sensor part is extremely great.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 is a perspective view showing an external appearance of an ultrasonic sensor device 1 which is an electronic circuit device according to an embodiment to which the present invention is applied. FIG. 1A is an overall view, and FIG. Part B is shown in an enlarged view. 2 and 3 are perspective views for explaining an assembly process of the ultrasonic sensor device 1. FIG. 4 is a cross-sectional view of a main part of the ultrasonic sensor device 1, and FIG. 5 is a perspective view of a main part of the ultrasonic sensor device 1.

  An ultrasonic sensor device 1 shown in FIG. 1A includes a case 20 (corresponding to a case body) and a cover 30 (corresponding to a cover member) forming an outer casing, and an electronic circuit unit 10 (corresponding to a cover member). 2) and a sealing resin 40 (corresponding to a sealing member) for protecting the electronic circuit unit 10 from vibration, water, dust, and the like.

  The electronic circuit unit 10 has a sensor unit 11 exposed on the outer surface of the case 20, and the ultrasonic sensor device 1 is mounted on a bumper or the like of a vehicle and transmits / receives ultrasonic waves by the sensor unit 11, and This is a device for detecting the distance to an obstacle or the like.

  The case 20 has a shape in which a rectangular tube portion 21 on the upper side in the drawing and a cylindrical portion 22 on the lower side in the drawing are connected, and as shown in FIG. 2, the electronic circuit portion 10 is accommodated therein. Yes. And the sensor part 11 is accommodated in the cylindrical part 22, and the front-end | tip part of the sensor part 11 is exposed in the bottom face of the cylindrical part 22. FIG. In addition, a connector 23 is provided on a side surface of the rectangular tube portion 21, and a terminal portion of the connector 23 is electrically connected to the electronic circuit portion 10.

  As shown in FIG. 2, the case 20 is configured such that the upper side of the rectangular tube portion 21 is open, and a cover 30 is mounted inside the opening edge portion 24. The cover 30 has a substantially rectangular shape corresponding to the opening shape of the case 20, and an injection port 31 for injecting a liquid resin 41 (see FIG. 4) serving as the sealing resin 40 at a position slightly shifted from the center. And a fitting wall portion 32 that fits inside the opening edge 24 of the case 20 is formed at the peripheral portion.

  Both the case 20 and the cover 30 are formed by injection molding of a resin material (for example, polybutylene terephthalate resin). In this example, the case 20 and the cover 30 are each formed by a plurality of molds.

  A part of the opening edge 24 of the case 20 on the side where the connector 23 is provided is a lower portion 241 having a lower height than the remaining portion. This low-order part 241 is for facilitating processing in the case 20 (for example, electrical connection processing between the electrical circuit unit 10 and the connector 23 terminal unit) after the electronic circuit unit 10 is housed in the case 20. Is formed.

  FIG. 1B is an enlarged view of part B of FIG. 1A, and FIG. 4 is a longitudinal sectional view of part B (longitudinal section of the lower portion 241 region in the state where the case 20 and the cover 30 are assembled). FIG. However, FIG.1 (b) has shown the cover 30 single-piece | unit before inject | pouring liquid resin.

  As shown in FIG. 4, the opening edge 24 of the case 20 is formed with a plurality of step portions so that the height dimension (the vertical dimension in the drawing) decreases toward the inside. On the other hand, the fitting wall portion 32 of the cover 30 has a plurality of height dimensions (vertical dimensions in the drawing) that increase toward the inside so as to correspond to the stepped portion on the inner side surface of the opening edge 24 of the case 20. A step is formed.

  Then, the cover 30 is mounted so as to be fitted inside the case 20, and an inner side surface having a step portion of the case 20 opening edge portion 24 and an outer side surface having a step portion of the cover 30 fitting edge portion 32 are formed. A contact portion 50 is formed that contacts and bends. The sealing resin 40 described above is filled so as to fill the storage space of the electronic circuit unit 10 formed by the case 20 and the cover 30, and is located above the inner end 501 of the contact part 50 between the case 20 and the cover 30. To the inlet 31 of the cover 30 located in

  As shown in FIGS. 1B and 4, the portion of the cover 30 that is above the lower case portion 241 of the case 20 has a rectangular cross section extending upward from the outer end portion 502 of the contact portion 50 (in this example, a depth). A plurality of collecting grooves 34 having a square shape of about 1 mm in width and about 1 mm in width are formed at equal intervals. The collection groove 34 is for collecting and collecting the liquid resin 41 that has passed through the contact portion 50 and leaked to the outer peripheral end portion 502, from the inner end portion 501 of the contact portion 50. The path length to the outer end portion 502 is shorter than the other portions, and the position of the outer end portion 502 is also lower than the other portions.

  Next, a method for assembling the ultrasonic sensor device 1 having the above configuration will be briefly described.

  First, as shown in FIG. 2, the electronic circuit unit 10 is mounted in the case 20. Next, the cover 30 is fitted and mounted inside the opening edge 24 of the case 20.

  Further, as shown in FIG. 3, a liquid that becomes a sealing resin 40 by using a filling machine 100 such as a dispenser in an electronic circuit unit 10 storage space formed by the case 20 and the cover 30 from the inlet 31 of the cover 30. The resin 41 is filled. In this example, a urethane resin is used as the liquid resin 41. As shown in FIG. 4, the liquid resin 41 is filled up to the opening position of the injection port 31 where the upper surface 411 is above the inner end 501 of the contact portion 50. Incidentally, the upper surface 411 of the liquid resin 41 is not only above the inner end 501 of the contact part 50 but also above the outer end 502 higher than the inner end 501 of the contact part 50.

  When the filling of the liquid resin 41 into the electronic circuit unit 10 storage space is completed, the resin is heat-cured (for example, heat-cured at 80 ° C. for about 10 minutes) to cure the liquid resin 41 to obtain the sealing resin 40.

  According to the above-described configuration and assembly method, the collection groove 34 extending upward from the outer end portion 502 of the contact portion 50 between the case 20 and the cover 30 is formed on the outer surface of the cover 30. As a result, as shown in FIGS. 4 and 5, the liquid resin 41 that passes through the contact portion 50 between the case 20 and the cover 30 and leaks to the outside is guided upward by the collecting groove 34 and collected. It is possible to prevent the case 20 from sagging on the outer surface.

  Further, since the collection groove 34 extends upward, the collection groove 34 is collected when the collection force in the direction in which the liquid resin 41 is pulled up by the collection groove 34 and the weight of the liquid resin 41 in the collection groove 34 are balanced. Therefore, it is possible to suppress the collection force of the collection groove 34 from promoting the leakage of the liquid resin 41 via the contact portion 50.

  Furthermore, since the collection groove 34 has a rectangular cross section, it is possible to reliably secure a collection volume that can be collected while exhibiting the collection force of the collection groove 34 due to the cross-sectional shape having corners. it can.

  Immediately after the heat curing of the liquid resin 41 is started, the viscosity drop due to the plasticization of the polymer due to the temperature rise is larger than the viscosity increase due to the bonding between the polymers due to the heat curing reaction, and the liquid resin 41 is larger than the time of the injection. Viscosity decreases temporarily. When the liquid resin 41 reaches the minimum viscosity, the leakage of the liquid resin 41 becomes maximum, but the liquid resin 41 leaked at this time can be collected in the collection groove 34.

  When the case 20 and the cover 30 are each molded with a plurality of molds as in this embodiment, the contact portion that can suppress the intrusion of the liquid resin 41 regardless of the combination of the case 20 and the cover 30. If it is going to obtain 50 adhesion | attachment states, there will be a problem that adjustment of a metal mold | die and adjustment of molding conditions will require time and process management will become very complicated.

  However, in the present embodiment, since the leaked liquid resin 41 is collected by the collecting groove 34 so as not to drip, it is only necessary to form a protrusion corresponding to the collecting groove 34 in the molding die of the cover 30. It ’s enough.

  When the collection groove 34 is not formed, for example, as shown in FIG. 6, the liquid resin 41 serving as the sealing resin 40 enters the clearance of the contact portion 950 between the case 920 and the cover 30 and faces the outside. The liquid resin may sag (liquid mass) 941 on the outer surface of the case 920 (see also FIG. 7). This sagging may cause an obstacle when the ultrasonic sensor device 1 is mounted on a vehicle, or the sensor may cause a malfunction when attached to the sensor unit.

  On the other hand, according to the present embodiment, by preventing the liquid resin 41 from dripping onto the outer surface of the case, the liquid resin 41 adheres to the outer surface of the case 20 and becomes an obstacle during mounting. It is possible to reliably prevent the resin from adhering to the sensor portion 11 exposed on the outer peripheral surface of the wire and hindering the transmission and reception of ultrasonic waves.

(Other embodiments)
In the above-described embodiment, the collection groove 34 is formed at a position corresponding to the lower portion 241 of the opening edge 24 of the case 20 on the outer surface of the cover 30, but is also formed at other portions. Also good.

  Moreover, in the said one Embodiment, although the collection groove | channel 34 was formed so that it might extend upward from the outer side edge part 502 of the contact part 50, it may extend in another direction. Further, the width and depth of the collecting groove 34 may not be the same in the extending direction, and may change in the extending direction. Further, the collecting groove may have a branched structure or the like. Furthermore, the cross-sectional shape of the collecting groove is not limited to a rectangular shape, and may be a triangular shape, for example.

  In the above embodiment, the case where the present invention is applied to the ultrasonic sensor device 1 has been described. However, the present invention may be applied to other sensor devices. In particular, if the sensor unit is a sensor device that is exposed on the outer surface of the case body, resin adhesion to the sensor unit can be prevented, and it is very effective without causing functional failure of the sensor unit. In addition, the present invention is widely applicable and effective as long as it is an electronic circuit device that seals the electronic circuit portion housed in the space formed by the case body and the cover member, not limited to the sensor device.

It is a perspective view which shows the external appearance of the ultrasonic sensor apparatus 1 which is the electronic circuit apparatus in one Embodiment to which this invention is applied, (a) is a general view, (b) is B part expansion in (a) which is a principal part. FIG. 5 is a perspective view for explaining a part of the assembly process of the ultrasonic sensor device 1. FIG. 5 is a perspective view for explaining a part of the assembly process of the ultrasonic sensor device 1. FIG. 1 is a cross-sectional view of a main part of an ultrasonic sensor device 1. 2 is an enlarged perspective view of a main part of the ultrasonic sensor device 1. FIG. It is sectional drawing of the site | part of the comparative example corresponding to the principal part of FIG. It is an external appearance perspective view of the site | part of the comparative example shown in FIG.

Explanation of symbols

1 Ultrasonic sensor device (electronic circuit device)
10 Electronic circuit part 11 Sensor part 20 Case (case body)
25, 33 Contact surface (site to be the contact portion 50)
30 Cover (cover member)
34 Collection groove 40 Sealing resin (sealing member)
41 liquid resin 50 contact part 411 upper surface (upper surface of liquid resin 41)
501 Inner end (inner end of contact 50)
502 Outer end (outer end of contact 50)

Claims (5)

An electronic circuit part forming an electronic circuit;
A case body that houses the electronic circuit portion therein;
A cover member for closing the opening of the case body;
A liquid resin filled in the case body is cured, and includes a sealing member for sealing the electronic circuit part,
An electronic circuit device in which an upper surface when the sealing member is filled in the case body in the state of the liquid resin is above an inner end of a contact portion where the case body and the cover member are in contact with each other. There,
An electronic circuit device, wherein a collecting groove for collecting the liquid resin that has passed through the contact portion is formed on an outer surface of the cover member.   The electronic circuit device according to claim 1, wherein the collection groove extends upward from an outer end portion of the contact portion.   The electronic circuit device according to claim 1, wherein the collection groove has a rectangular cross-sectional shape.   The electronic circuit device according to any one of claims 1 to 3, wherein the electronic circuit unit includes a sensor unit exposed on an outer surface of the case body.   The electronic circuit device according to claim 4, wherein the sensor unit performs at least one of transmission and reception of ultrasonic waves.

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