JP2010056186A - Electrical and electronic module - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electrical and electronic module capable of suppressing contact with an external environment of an electronic circuit board. <P>SOLUTION: The electrical and electronic module includes the electronic circuit board 5 and a metallic base 1 mounted with the electronic circuit board 5 and seals the electronic circuit board 5 with a sealing resin 8. In the electrical and electronic module, the metallic base 1 includes a step 20 with a riser surface 21 opposed to the outer periphery of an adhesive interface with the sealing resin 8. A recess 9 formed between the sealing resin 8 and the riser surface 21 is filled with a resin composition 12. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an electric / electronic module having a resin sealing structure.

  Electrical and electronic modules mounted on automobiles and the like are required to have a configuration that protects an electronic circuit board by preventing intrusion of water or corrosive gas.

  As such an electric / electronic module, an electronic circuit board on which an electronic circuit is mounted and a metal base on which the electronic circuit board is mounted is known, and the electronic circuit board is sealed with a resin. (Refer to patent document 1 etc.).

JP 2007-273796 A

  In the above-described conventional electric / electronic module, when an adhesion inhibiting substance (for example, machine oil) adheres to the adhesion surface between the metal base and the sealing resin, the adhesion between the metal base and the sealing resin is caused by the adhesion inhibiting substance. It is considered that the adhesive surface is weakened and peels off. If such peeling of the adhesive surface occurs continuously between the electronic circuit board and the external environment, the electronic circuit board will be in contact with the external environment, so that a short circuit between the circuit wiring due to moisture penetration, or There is a risk of circuit wiring breakage due to the intrusion of corrosive gas.

  The present invention has been made in view of the above, and an object of the present invention is to provide an electrical and electronic module capable of suppressing contact of an electronic circuit board with an external environment.

  In order to achieve the above object, the present invention is an electrical and electronic module comprising an electronic circuit board and a metal base to which the electronic circuit board is attached, wherein the electronic base is sealed with a sealing resin. A rising surface facing the outer peripheral portion of the adhesive interface with the sealing resin is provided, and a resin composition is filled in a recess formed between the sealing resin and the rising surface.

  Contact of the electronic circuit board with the external environment can be suppressed.

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

  FIG. 1 is a five-side view showing an electric / electronic module according to the present embodiment. FIGS. 1A to 1E are a front view, a bottom view, a rear view, a right side view, and a plan view, respectively. It is. 2 is a perspective view showing the entire electric / electronic module, FIG. 3 is a cross-sectional view taken along line AA in FIG. 1 (e), and FIG. 4 is a perspective view showing the electric / electronic module before resin sealing with resin. FIG. 5 and FIG. 5 are exploded sectional views thereof.

  1 to 5, the electrical and electronic module of the present embodiment includes a metal base 1 on which an electronic circuit board 5 on which electronic components are mounted and mounted, a connector 2 on which metal terminals 3 are assembled, and an electronic circuit. It is schematically configured with a sealing resin 8 that seals the substrate 5.

  An opening for allowing the metal terminal 3 assembled to the connector 2 to pass through is provided on the front side (the left side in FIG. 3 and the like) of the metal base 1, and the connector 2 is fixed to the periphery of the opening. A mounting portion 1b is provided. The connector 2 is fixed to the mounting portion 1b with a connector fixing screw 6 or an adhesive (not shown). When the connector 2 is attached to the attachment portion 1b, the metal terminal 3 is accommodated along the inside of the rising portion 1a connected to the attachment portion 1b of the metal base 1. A terminal alignment plate 4 provided with a guide hole for allowing the metal terminal 3 to pass therethrough is disposed at the tip of the metal terminal 3 (upper part of the rising portion 1 a). The metal terminal 3 is a guide for the terminal alignment plate 4. It is inserted into the hole and aligned, and insertion into the terminal connection hole provided in the electronic circuit board 5 becomes easy.

  The electronic circuit board 5 is a circuit board in which a pattern of an electronic circuit is wired, and various electronic components corresponding to the function of the electronic circuit are mounted and mounted by solder or silver paste adhesive (both not shown). It is attached and fixed to the metal base 1 with screws 7 or an adhesive (not shown). The electronic circuit board 5 is provided with terminal connection holes, and when the electronic circuit board 5 is mounted on the metal base 1, the electronic circuit board 5 is conductively connected to the metal terminal 3 by solder or the like. As a material of the electronic circuit board 5, for example, ceramic, glass epoxy, or metal is used.

  The metal base 1 serves as a fixing member for attaching the electric / electronic module, and also serves as a heat radiating member for heat generated from the electronic circuit board 5 fixed to the metal base 1. The metal base 1 is made of, for example, aluminum, aluminum alloy, copper, copper alloy, or iron (including those whose surfaces are plated (processed)) by die casting, pressing, sintering, or cutting. Molded.

  The connector 2 is a component for electrically connecting a harness (not shown) provided outside the electric / electronic module and the electronic circuit board 5, and the electronic circuit board 5 is connected via the metal terminals 3 of the connector 2. The power supply is received, signal input from an external sensor (not shown), or signal output to an external actuator (not shown) is performed. As a housing material of the connector 2, for example, a thermoplastic resin (polybutylene terephthalate (PBT), nylon (PA66), polyphenylene sulfide (PPS), etc.) containing an inorganic filler is used. Moreover, as a material of the metal terminal 3, for example, a brass material subjected to tin plating or gold plating is used.

  As a material of the sealing resin 8, for example, an epoxy resin (thermosetting resin) that includes an inorganic filler and is solid at 40 degrees or less is used.

  The epoxy resin material is composed of an epoxy resin and a phenol resin curing agent. Examples of the epoxy resin include an orthocresol type epoxy resin solid at 40 degrees or less, an epoxy resin having a biphenyl skeleton, an epoxy resin having a dicyclopentadiene skeleton, an epoxy resin having a naphthalene skeleton, and a bisphenol A type epoxy resin. Used. Moreover, as a phenol resin hardening | curing agent, a phenol novolak resin, an ortho cresol novolak resin, a phenol resin which has a dicyclopentadiene skeleton, a phenol resin which has a naphthalene skeleton, etc. are used, for example.

  The epoxy resin molding material may contain a stress reducing agent such as silicone rubber or oil-based or butadiene-based rubber in order to reduce the elastic modulus.

  Examples of the inorganic filler added to the epoxy resin include crushed or spherical fillers such as fused silica, crystalline silica, alumina, and magnesium oxide. When adding to an epoxy resin, 1 or more types of fillers can be added.

  In the electric and electronic module configured as described above, a configuration excluding the sealing resin 8 (that is, an assembly before resin sealing) is referred to as a module sub-assembly 13.

  The electric / electronic module in the present embodiment is obtained by resin-sealing the module sub-assembly 13 by a transfer molding method.

  In addition, although the characteristic part of this invention exists in the outer peripheral part of the adhesive surface with the sealing resin 8 in the metal base 1 of an electric / electronic module, since drawing becomes complicated, illustration is abbreviate | omitted in FIGS. This will be described in detail later.

  6-8 is a figure which shows an example of the transfer mold shaping | molding method of the electrical / electronic module in this Embodiment.

  In the transfer mold molding method according to the present embodiment, resin sealing of the module sub-assembly 13 is performed using an upper mold 14, a lower mold 15, a molded resin tablet 8 </ b> T, and the like that are molding dies.

  The upper mold 14 and the lower mold 15 are dug into a desired sealing resin shape for outer shape molding. The lower mold 15 is provided with a pot 15a for loading a molded resin tablet 8T that is in a solid state at room temperature, and a plunger 16 for pushing the molded resin tablet 8T into the mold from the pot 15a.

  Hereinafter, the procedure of the transfer mold forming method will be described.

  (Procedure 1) The upper mold 14 and the lower mold 15 are preheated to 170 ° C. to 180 ° C., and the module sub-assembly 13 is set on the lower mold 15 and the molded resin tablet 8T is loaded into the pot 15a (see FIG. 6 (1)). The cycle time can be shortened by preheating the module sub-assembly 13 at a predetermined temperature in advance.

  (Procedure 2) The upper mold 14 and the lower mold 15 are clamped with a force of several tens of tons (FIG. 6 (2)).

  (Procedure 3) By pushing up the plunger 16 at an arbitrary speed (FIG. 6 (3)), the molten molded resin tablet 8T (sealing resin 8) is molded through the resin filling opening (gate). The inside (cavity) is filled (FIG. 7 (4)).

(Procedure 4) When the mold is filled with the sealing resin 8, a molding pressure of several tens of kgf / cm ² is applied and the state is maintained for about 3 minutes (FIG. 7 (5)).

  (Procedure 5) The molding die (upper die 14 and lower die 15) is opened, and the module sub-assembly 13 that has been sealed with the sealing resin 8 is taken out (FIGS. 7 (6) and 8 (7)). .

  (Procedure 6) Cull 18, which is an extra part of the electric / electronic module, is removed (FIG. 8 (8)).

  In the electrical / electronic module according to the present embodiment, after the module sub-assembly 13 is resin-sealed by transfer molding, a recess 9 (described later) is formed on the outer peripheral portion of the bonding interface between the metal base 1 and the sealing resin 8. Is filled with a resin composition. Hereinafter, this point will be described in detail with reference to FIGS.

  9 and 10 are diagrams showing the electric / electronic module before filling the resin composition, and FIG. 11 is a diagram showing the electric / electronic module after filling the resin composition. 9 is a cross-sectional view at a position corresponding to the line BB in FIG. 1E, and FIG. 10 is an enlarged view of a portion C in FIG. Moreover, FIG. 11 is sectional drawing corresponding to FIG. 9 in the electric and electronic module after resin composition filling.

  9 to 11, the metal base 1 includes a stepped portion 20 having a rising surface 21 that faces the outer peripheral portion of the adhesive interface with the sealing resin 8.

  The step portion 20 is above the bonding interface 10 (shown by a dotted line 10 for convenience of explanation) between the metal base 1 and the sealing resin 8 (on the metal base 1, the electronic circuit board 5 is mounted and sealed with the sealing resin 8. And a stepped surface 11 (shown by a dotted line 11 for convenience of description), and the adhesive interface 10, the rising surface 21, and the stepped surface 11 are formed continuously. That is, the rising surface 21 is formed to extend upward from the bonding interface 10.

  The stepped portion 20 and the rising surface 21 are provided so as to surround the adhesion interface (the outer periphery thereof) between the metal base 1 and the sealing resin 8 except for the resin filling opening (gate) at the time of transfer molding. .

  A recess 9 is formed by the rising surface 21 of the stepped portion 20 and the sealing resin 8 formed as described above, and the recess 9 is filled with the resin composition 12 (see FIG. 11).

  As a material of the resin composition 12, for example, a silicone-based or polyisobutylene-based liquid gasket, or a silicone-based or epoxy-based adhesive is used.

  The effects of the present embodiment configured as described above will be described in comparison with the prior art.

  In the electric / electronic module, since the metal base 1 is formed by die casting, pressing, sintering, cutting, or the like, it is conceivable that machine oil or the like used in the forming process adheres and remains on the metal base 1.

  In a conventional electric / electronic module, a sealing resin for sealing an electronic circuit board and a metal base are bonded together by an adhesive force generated between them. Therefore, when an adhesion inhibiting substance (for example, machine oil) adheres to or remains on the adhesion surface (adhesion interface) between the metal base and the sealing resin, the adhesion force between the metal base and the sealing resin is weakened by the adhesion inhibiting substance, There is a risk that the adhesive interface will peel off.

  In particular, an electronic circuit board having a control circuit for an internal combustion engine may be large, sometimes exceeding 100 mm × 100 mm. When such an electronic circuit board is mounted on a metal base and resin-sealed to form an electrical / electronic module, the length of the outer periphery of the adhesive interface between the metal base and the sealing resin is increased, so that manufacturing management is possible. Are more susceptible to the influence of component defects (for example, adhesion of an adhesion-inhibiting substance to the adhesion interface), and the risk of the adhesion interface peeling off becomes greater.

  If such peeling of the adhesive surface occurs continuously between the electronic circuit board and the external environment, the electronic circuit board will be in contact with the external environment, so that a short circuit between the circuit wiring due to moisture intrusion, or There is a risk of circuit wiring breakage due to the intrusion of corrosive gas.

  On the other hand, in the electric and electronic module according to the present embodiment, the metal base 1 is provided with the stepped portion 20 having the rising surface 21 facing the outer peripheral portion of the adhesive interface with the sealing resin 8, and the rising surface 21 Since the concave portion 9 formed between the sealing resin 8 is filled with the resin composition 12, even if the adhesive interface between the sealing resin 8 and the metal base 1 is peeled off, the outer periphery of the adhesive interface The part is prevented from coming into contact with the external environment, and the electronic circuit board 5 can be prevented from coming into contact with the external environment.

  Further, since the rising surface 21 is formed only by the stepped portion 20, it is possible to prevent the mold structure used for resin molding (transfer molding) from becoming complicated by providing the rising surface 21.

  In the above description, the case where there is a gap between the sealing resin 8 and the rising portion of the rising surface 21 (boundary portion with the adhesive interface 10) has been described as an example. 8 and the rising portion of the rising surface 21 may be in contact with each other.

  Further, in the above, the concave portion 9 filled with the resin composition 12 is formed by the sealing resin 8 and the rising surface 21 of the stepped portion 20, but not limited thereto, for example, a tapered portion having the rising surface 21, or A convex portion having a rising surface 21 is provided on the outer peripheral portion of the adhesion interface between the metal base 1 and the sealing resin 8, and a concave portion 9 is formed by the rising surface 21 and the sealing resin 8 to fill the resin organism 12. It may be configured.

FIG. 6 is a five-side view showing the electric and electronic module in the present embodiment. It is a perspective view which shows the whole electric / electronic module in this Embodiment. It is the sectional view on the AA line in FIG. It is a perspective view which shows the electric and electronic module before resin sealing with resin. FIG. 5 is an exploded sectional view in FIG. 4. It is a figure which shows an example of the transfer mold molding method. It is a figure which shows an example of the transfer mold molding method. It is a figure which shows an example of the transfer mold molding method. It is sectional drawing which shows the electric and electronic module before resin composition filling. It is sectional drawing which shows the electric and electronic module before resin composition filling. It is sectional drawing which shows the electric and electronic module after resin composition filling.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Metal base 2 Connector 3 Metal terminal 4 Terminal alignment board 5 Electronic circuit board 6 Connector fixing screw 7 Board fixing screw 8 Sealing resin 9 Recess 10 Adhesive interface 11 Step surface 12 Resin composition 13 Module sub-assembly 14 Upper mold 15 Lower mold 20 Stepped portion 21 Rising surface

Claims (5)

In an electrical and electronic module comprising an electronic circuit board and a metal base to which the electronic circuit board is attached, and sealing the electronic circuit board with a sealing resin,
The metal base includes a rising surface facing an outer peripheral portion of an adhesive interface with the sealing resin,
An electrical and electronic module, wherein a recess formed between the sealing resin and the rising surface is filled with a resin composition. The electrical and electronic module according to claim 1.
The electric and electronic module, wherein the resin composition is an adhesive. The electrical and electronic module according to claim 2,
The electrical and electronic module is characterized in that the adhesive is a silicone adhesive or an epoxy adhesive. The electrical and electronic module according to claim 1.
The electric and electronic module, wherein the resin composition is a liquid gasket. The electrical and electronic module according to claim 4.
The electrical and electronic module, wherein the liquid gasket is a silicone-based liquid gasket or a polyisobutylene-based liquid gasket.

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