JP2012129344A - Electronic circuit device and manufacturing method of the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electronic circuit device which eliminates a process in which a case is joined to a cover with laser welding and a process in which the case is bonded to the cover with an adhesive and improves the rigidity.SOLUTION: An electronic circuit device includes a circuit board housed in an interior space SP formed by a metal case 101 and a cover 102. The case 101 and the cover 102 respectively has opposite surface parts 101A, 102A which face each other sandwiching the interior space SP and side surface parts 101B, 102B erected from the circumference of the opposite surface parts 101A, 102A. The cover 102 is fitted into the case 101 so that the side surface 102B gets into the inner side of the side surface part 101B of the case 101. The side surface part 102B of the cover 102 is fixed to the case 101 with a sealing resin 105 which fills the interior of the case 101 to seal the circuit board 103A and is cured.

Description

  The present invention relates to an electronic circuit device and a method for manufacturing the electronic circuit device. More specifically, the present invention relates to an electronic circuit device including a metal case and cover, and a circuit board housed in an internal space formed by the case and cover, and a method for manufacturing the electronic circuit device.

  For example, a vehicular lamp using a discharge bulb as a light source includes a control circuit (referred to as a ballast or the like) for controlling lighting of the discharge bulb (see, for example, Patent Document 1). Such a control circuit has the following configuration, for example. That is, a circuit board is disposed inside a housing formed of a metal case and a cover, and the circuit board is fixed to the case by bonding or the like while being grounded to the case.

Japanese Patent Laid-Open No. 2006-210009

  By the way, the control circuit having the configuration as described above has a configuration in which a metal cover is attached so as to cover the resin cover after the resin cover is fixed to the case by a method such as adhesion in order to supplement the rigidity of the housing. And In this case, a method such as laser welding is used for joining the case and the cover. Therefore, many steps are required to assemble a conventional control circuit.

  In order to solve the above problems, the present invention is an electronic circuit device comprising a metal case and cover, and a circuit board housed in an internal space formed by the case and the cover, Each of the case and the cover has a facing surface portion facing each other across the internal space, and a side surface portion rising from a peripheral edge of the facing surface portion, and the side surface portion of the cover is more than the side surface portion of the case. The cover is fitted into the case so as to enter the inside, and the side surface portion of the cover is fixed to the case by a sealing resin filled and cured inside the case so as to seal the circuit board. An electronic circuit device is provided.

  According to such an electronic circuit device, since the case and the cover are fixed by the resin for sealing the circuit board, the case and the cover are bonded to each other by using a process of joining the case and the cover by laser welding or using an adhesive. The step of adhering can be omitted. In addition, since the rigidity of the case is improved by the rigidity of the cured sealing resin, no separate parts are required to give the case rigidity.

  In the electronic circuit device, it is preferable that the cover has a contact portion that contacts an outer surface of the side surface portion of the case in a state where the side surface portion is fitted into the side surface portion of the case.

  Thereby, the case and the cover can be easily and reliably brought into conductor contact without using laser welding or the like.

  In the electronic circuit device, it is preferable that the contact portion is provided at a branch portion branched from the side surface portion of the cover, and the side surface portion of the case is sandwiched between the side surface portion of the cover. .

  Thereby, the case and the cover can be brought into conductor contact more reliably.

  According to another aspect of the present invention, there is provided a method for manufacturing an electronic circuit device comprising a metal case and cover, and a circuit board housed in an internal space formed by the case and the cover, After the circuit board is disposed inside the case, a sealing resin filling step of filling the inside of the case with a sealing resin so as to seal the circuit board, and the side portion of the cover is the side of the case An electronic circuit comprising: a fitting step of fitting the cover into the case so as to enter the inside of the side surface portion and contact the sealing resin; and a curing step of curing the sealing resin An apparatus manufacturing method is provided.

  According to the electronic circuit device manufactured by such a manufacturing method, the case and the cover are bonded by the resin for sealing the circuit board. Therefore, in order to fix the cover to the case, the case and the cover are laser welded. It is possible to omit the step of bonding and the step of bonding the case and the cover using an adhesive. Moreover, since the rigidity of the case is improved by the sealing resin being cured, a separate component is not required to give the case rigidity.

  The above summary of the invention does not enumerate all the necessary features of the present invention, and sub-combinations of these feature groups can also be the invention.

1 is a longitudinal sectional view of a vehicular lamp 10. FIG. FIG. 3 is a perspective view showing a portion where a heat radiating fin 42 is provided on the upper surface of a lamp body 40 of a vehicular lamp 10. It is the figure which expanded a part of longitudinal section of electronic circuit device 100 with which vehicular lamp 10 is provided. It is the figure which expanded a part of longitudinal section of other examples of composition of electronic circuit device 100.

  DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, an embodiment of the present invention will be described with reference to the accompanying drawings. However, the following embodiment does not limit the invention according to the scope of claims, and all combinations of features in the embodiment do not limit the invention. It is not always essential to the solution.

  FIG. 1 is a longitudinal sectional view of a vehicular lamp 10 including an electronic circuit device 100 according to an embodiment of the present invention. FIG. 2 is a perspective view showing an extracted portion of the upper surface of the lamp body 40 of the vehicular lamp 10 where the radiation fins 42 are provided.

  A vehicular lamp 10 according to the present embodiment is used for, for example, a headlamp of an automobile, and includes a front cover (cover) 20, an extension 30, a lamp body 40, a rear cover 60, a gasket 70, a reflector 80, and a circuit device. A protective cover 90, an electronic circuit device 100, a bulb socket 110, a discharge bulb 120, a shade 130, a lead wire 140, and a connector 150 are provided. In FIG. 1, for convenience of explanation, only the front cover (cover) 20, the extension 30, the lamp body 40, the rear cover 60, the reflector 80, and the circuit device protective cover 90 among the above-described configuration of the vehicular lamp 10 are shown in cross section. As shown.

  Further, in the present specification, “lamp front” or “front” is, for example, the left direction in FIG. 1 and means a direction from the rear cover 60 side to the front cover 20 side in the vehicle lamp 10. “Ramp rear” or “rear” means the direction opposite to the front of the lamp (for example, the right direction in FIG. 1). Further, “upper” or “lower” is “upper” or “lower” in FIG. 1 and is a direction orthogonal to the front-rear direction of the lamp.

  The lamp body 40 is a cylindrical part having an opening on the front side and the rear side of the lamp, and is formed of a material having excellent thermal conductivity such as aluminum die casting. In this example, a flange portion 41 is provided around the entire periphery of the opening of the lamp body 40 on the front side of the lamp. Moreover, the recessed part for fitting the gasket 70 over the perimeter is provided in the periphery of the opening of the lamp back side. Further, as shown in FIGS. 1 and 2, a plurality of heat radiating fins 42 protruding upward and extending in the front-rear direction of the lamp are provided on the upper surface of the lamp body 40 at intervals.

  The vehicular lamp 10 is configured such that heat generated from the electronic circuit device 100 and the discharge bulb 120 disposed inside the lamp body 40 (in the lamp chamber) is transmitted to the upper side of the lamp chamber by natural convection of air in the lamp chamber. However, since the plurality of heat radiation fins 42 are provided on the upper surface of the lamp body 40 as described above, the heat transmitted to the upper surface of the lamp body 40 can be efficiently radiated. . The heat radiation fin 42 may be formed integrally with the lamp body 40, but may be provided as a separate component and attached to the upper surface of the lamp body 40.

  The front cover 20 is formed of, for example, a transparent or translucent resin, and covers the front of the vehicular lamp 10. A flange insertion portion 21 that protrudes toward the rear side of the lamp is provided on the peripheral portion of the front cover 20. The flange insertion portion 21 is inserted into a concave groove of a flange portion 41 provided over the entire circumference of the lamp body 40, and is fixed to the lamp body 40 via a sealant 50 sealed in the concave groove. Yes.

  The extension 30 is a substantially ring-shaped part formed of resin or metal, and is fixed to the lamp body 40 by a method such as screwing. The extension 30 serves to prevent the configuration behind the lamp from being seen from the gap between the reflector 80 and the lamp body 40 when the vehicular lamp 10 is viewed from the outside of the front cover 20. Further, the extension 30 may be provided with a reflecting surface that diffuses or collects part of light emitted from the discharge bulb 120 (hereinafter referred to as “light source light”).

  The rear cover 60 is a substantially disk-shaped component, and is attached to the opening of the lamp body 40 on the rear side of the lamp by a method such as screwing to cover the opening. Further, in this example, a gasket 70 is fitted in a recess provided in a peripheral portion of an opening on the lamp rear side of the lamp body 40. The gasket 70 prevents water and the like from entering the lamp chamber from the joint between the lamp body 40 and the rear cover 60. As with the lamp body 40, the rear cover 60 is preferably formed of a material having excellent thermal conductivity such as aluminum die casting.

  The discharge bulb 120 is arranged at the center of the lamp chamber so that its longitudinal direction is along the front-rear direction of the lamp, and is fixed to the bulb socket 110 on the rear side. The discharge bulb 120 is turned on by the electronic circuit device 100 attached to the rear side of the bulb socket 110. Although not shown, the electronic circuit device 100 and the bulb socket 110 are fixed to the lamp body 40 directly or indirectly through other components.

  The electronic circuit device 100 incorporates a starter circuit for lighting the discharge bulb 120 and a ballast circuit for controlling the lighting state of the discharge bulb 120, and electrodes supplied from a power source such as a battery via the connector 150 and the lead wire 140. Drive by. A more specific configuration of the electronic circuit device 100 will be described later.

  The reflector 80 has a paraboloid convex toward the rear of the lamp, and reflects the light source light from the discharge bulb 120 toward the front of the lamp on the inner surface including the paraboloid. As shown in FIG. 1, the reflector 80 of the present example is provided with an opening through which the discharge bulb 120 is inserted from the rear side of the lamp at the center of the paraboloid. A circuit device protection cover 90 for protecting the electronic circuit device 100 is attached to the rear side of the lamp of the reflector 80.

  FIG. 3 is an enlarged view of a part of a longitudinal sectional view of the electronic circuit device 100. As shown in FIG. 3, the electronic circuit device 100 includes a case 101, a cover 102, and a control circuit unit 103.

  The case 101 is a substantially cylindrical part, and includes a flat surface portion 101A and a side surface portion 101B that rises from the periphery of the flat surface portion 101A. The cover 102 is a substantially cylindrical part similar to the case 101, and includes a flat surface portion 102A and a side surface portion 102B that rises from the periphery of the flat surface portion 102A. In this example, both the case 101 and the cover 102 are formed of a conductor such as metal.

  As shown in FIG. 3, the cover 102 is fitted into the case 101 so that the side surface portion 102 </ b> B enters the inside of the side surface portion 101 </ b> B of the case 101, and an internal space SP is formed by the case 101 and the cover 102. ing. Here, the flat surface portion 101A of the case 101 and the flat surface portion 102A of the cover 102 are opposed to each other, and the front end surface of the side surface portion 102B of the cover 102 is stepped provided inside the side surface portion 101B of the case 101. It is in contact with the portion 101C.

  In addition, the side surface portion 102B of the cover 102 is formed with a protruding portion 102C that protrudes outward, and in a state where the cover 102 is fitted into the case 101, it makes conductive contact with the inner surface of the side surface portion 101B of the case 101. ing.

  The control circuit unit 103 includes a circuit board 103A and a ground terminal 103B that is electrically connected to a ground pattern formed on the circuit board 103A, and is accommodated in an internal space SP formed by the case 101 and the cover 102. Has been. As shown in FIG. 3, the circuit board 103 </ b> A is bonded to the inside of the flat portion 101 </ b> A of the case 101 via an adhesive 104, and the ground terminal 103 </ b> B is in contact with the flat portion 101 </ b> A of the case 101. Therefore, since the circuit board 103A is grounded by the case 101 and the cover 102 covering the surface of the electronic circuit device 100, electromagnetic noise generated in the control circuit unit 103 is difficult to leak to the outside of the electronic circuit device 100. The electronic circuit device 100 is not easily affected by electromagnetic noise from the outside.

  In addition, the control circuit unit 103 is sealed with a sealing resin 105. As the sealing resin 105, for example, an electrically insulating thermosetting resin having sufficient rigidity in a cured state is preferably used, and after being filled inside the case 101, it is heated and cured. Further, as shown in FIG. 3, the sealing resin 105 is filled up above the stepped portion 101 </ b> C inside the case 101. Therefore, the front end portion of the side surface portion 102 </ b> B in the cover 102 fitted in the case 101 is fixed to the case 101 by the sealing resin 105. At the time of manufacturing the electronic circuit device 100, the order in which the sealing resin 105 is filled inside the case 101 and then the cover 102 is fitted into the case 101 and the sealing resin 105 is cured is preferable. The sealing resin 105 may be hardened by filling the inside of the case 101 with the sealing resin 105 after fitting into the 101.

  As described above, in the electronic circuit device 100 according to the present embodiment, the case 101 and the cover 102 are fixed by the sealing resin 105 that seals the circuit board 103A. The step of adhering can be omitted. In addition, since the rigidity of the case 101 is improved by the rigidity of the cured sealing resin 105, no separate parts are required to give the case 101 rigidity.

  Further, by providing the protruding portion 102C on the side surface portion 102B of the cover 102, the side surface portion 102B of the cover 102 and the side surface portion 101B of the case 101 are surely brought into conductor contact, so that the case 101 and the cover 102 are brought into conductor contact. Further, for example, a step of joining each other by laser welding becomes unnecessary. Therefore, as compared with the case where the case 101 and the cover 102 are joined by laser welding, the case 101 or the cover 102 is not distorted due to heat at the time of joining, and as a result, the accuracy of the mounting position of the discharge bulb 120 is improved. To do.

  FIG. 4 is an enlarged view of a part of a longitudinal sectional view of another configuration example of the electronic circuit device 100. In the example shown in FIG. 4, the same components as those of the electronic circuit device 100 described with reference to FIG.

  As shown in FIG. 4, in the electronic circuit device 100 of the present example, the cover 102 has a branch portion 102D that branches outward from the side surface portion 102B. As shown in FIG. 4, the branch portion 102D has a tip portion extending along the side surface portion 102B, and a protruding portion 102E that protrudes inward is formed inside the tip portion of the branch portion 102D. Has been. In the state where the cover 102 is fitted in the case 101, the protruding portion 102E is provided not only in contact with the outer surface of the side surface portion 101B of the case 101 but also on the side surface portion 102B of the cover 102 as shown in FIG. The side surface portion 101B of the case 101 is sandwiched between the protruding portion 102C.

  With this configuration, the electronic circuit device 100 of this example can more reliably make the conductor contact between the side surface portion 102B of the cover 102 and the side surface portion 101B of the case 101. In addition, the protrusion part 102E of this example is only an example of a structure as a contact part which contacts the outer surface of the side part 101B of the case 101 in a state where the cover 102 is fitted in the case 101. Therefore, instead of the configuration in which a part of the branch portion 102D is protruded as in this example, the entire branch portion 102D may be in conductor contact with the side surface portion 101B of the case 101, for example.

  As mentioned above, although this invention was demonstrated using embodiment, the technical scope of this invention is not limited to the range as described in the said embodiment. It will be apparent to those skilled in the art that various modifications or improvements can be added to the above-described embodiment.

DESCRIPTION OF SYMBOLS 10 ... Vehicle lamp 20 ... Front cover 21 ... Flange insertion part 30 ... Extension 40 ... Lamp body 41 ... Flange part 42 ... Radiation fin 50 ... Sealant 60 ... Rear cover 70 ... Gasket 80 ... Reflector 90 ... Circuit apparatus protective cover 100 ... Electronic circuit device 101... Case 101A... Flat part (opposing surface part)
101B ... Side surface part 101C ... Stepped part 102 ... Cover 102A ... Plane part (opposite surface part)
102B ... Side part 102C ... Protrusion part 102D ... Branch part 102E ... Protrusion part (contact part)
DESCRIPTION OF SYMBOLS 103 ... Control circuit part 103A ... Circuit board 103B ... Ground terminal 104 ... Adhesive 105 ... Sealing resin 110 ... Valve socket 120 ... Discharge bulb 130 ... Shade 140 ... Lead wire 150 ... Connector

Claims (4)

An electronic circuit device comprising a metal case and cover, and a circuit board housed in an internal space formed by the case and the cover,
Each of the case and the cover has a facing surface portion facing each other with the internal space interposed therebetween, and a side surface portion rising from a peripheral edge of the facing surface portion, and the side surface portion of the cover is more than the side surface portion of the case. The side surface of the cover is fixed to the case with a sealing resin filled and cured inside the case so as to seal the circuit board. An electronic circuit device characterized by being made.   2. The electronic circuit device according to claim 1, wherein the cover has a contact portion that contacts an outer surface of the side surface portion of the case in a state where the side surface portion is fitted into the side surface portion of the case. .   The said contact part is provided in the branch part branched from the said side part of the said cover, The said side part of the said case is pinched | interposed between the said side parts of the said cover. Electronic circuit device. A method for manufacturing an electronic circuit device comprising a metal case and cover, and a circuit board housed in an internal space formed by the case and the cover,
After placing the circuit board inside the case, a sealing resin filling step for filling the inside of the case with a sealing resin so as to seal the circuit board;
A fitting step of fitting the cover into the case so that the side surface portion of the cover enters the inside of the side surface portion of the case and contacts the sealing resin;
A curing step for curing the sealing resin;
A method for manufacturing an electronic circuit device, comprising:

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