JP2010232575A - Electronic control unit for transmission - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electronic controller for a transmission which raises a reliability of a product, by suppressing a warpage caused by a difference of a linear expansion coefficient and by attaining a structure of preventing a terminal part from slipping out from sealing resin. <P>SOLUTION: There are provided laterally symmetrical notch parts 22a and projections in a part of a terminal part 22 covered with a sealing material 3. By providing the laterally symmetrical notch parts 22a in a part of a terminal, a shape of the terminal part 22 becomes symmetrical to a central axis thereof, and consequently it is possible to suppress a warpage produced when an internal stress distribution of the terminal part 22 becomes unsymmetrical. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an electronic control device for a transmission in which an electronic component and a substrate are encapsulated with a sealing resin, and in particular, the external size is relatively large like a vehicle-mounted electronic control device for a transmission, and heat generation is large. The present invention relates to an electronic control unit for a transmission used in high temperature, oil, and vibration environments.

  As an example of a structure for preventing the terminal portion from coming off from the sealing resin, in a resin-encapsulated semiconductor device with a small current carrying capacity with a relatively small outer size and a small calorific value, which is applied to a power supply device for home appliances, Patent Document 1 is known. In a semiconductor device in which a power element and a control element are mounted on a lead frame, and a heat radiating metal plate is arranged on the back surface of the lead frame, and its peripheral area is integrally sealed with resin, a sealing resin layer A notch is formed in the terminal part that is buried inside, the sealing resin flows into the notch part, and the cured sealing resin bites into the terminal part after curing. It was the structure which prevents a part from removing from sealing resin.

JP 2000-150720 A

  In the conventional structure of Patent Document 1, by forming a notch portion in the terminal portion buried in the sealing resin layer, the shape of the terminal portion becomes asymmetric with respect to the central axis. As a result, the internal stress distribution in the terminal part is also asymmetrical, so that the warpage caused by the thermal stress due to the difference in linear expansion coefficient occurs in the terminal part, causing the sealing resin to peel and crack. It was.

  In the present invention, a multilayer wiring board on which electronic components are mounted is bonded to a base member having a flange part and a terminal part via an adhesive, and the multilayer wiring board and the terminal part are electrically connected with a fine wire, An electronic control device for a transmission, which is covered with a sealing material so as to expose a part of the flange part and the terminal part, is characterized in that a part of the terminal is provided with a symmetrical notch part. Further, a part of the notch is exposed from the sealing material. Further, the notch is characterized by a semicircular shape, a triangular shape, a trapezoidal shape, and a rectangular shape. In addition, a plurality of notches are provided.

  The multilayer wiring board on which electronic components are mounted is bonded to a base member having a flange part and a terminal part via an adhesive, and the multilayer wiring board and the terminal part are electrically connected with a fine wire, and the flange part and the terminal are connected. An electronic control device for a transmission which is covered with a sealing material so as to expose a part of the part is characterized in that a part of the terminal is provided with a symmetrical convex part.

  According to the present invention, a multilayer wiring board on which electronic components are mounted is bonded to a base member having a flange portion and a terminal portion via an adhesive, and the multilayer wiring substrate and the terminal portion are electrically connected with a thin wire. In the electronic control device for a transmission which is covered with a sealing material so as to expose a part of the flange part and the terminal part, the shape of the terminal part can be changed by providing the terminal part with a symmetrical notch part. There is an advantage that the warpage caused by the symmetry of the central axis and the asymmetrical distribution of internal stress in the terminal portion can be suppressed. In addition, the sealing resin flows into the notch and cures so that the resin protrusion supports the terminal part, thereby preventing the terminal part from coming off the sealing resin due to a load in the tensile direction. There is an advantage that it can be prevented from coming off.

  By partially exposing the notch portion of the terminal portion from the sealing material, the cross-sectional area of the terminal portion is reduced at the boundary between the portion buried in the sealing resin and the exposed portion. By reducing the area of the interface between dissimilar materials, the thermal stress caused by the difference in linear expansion coefficient can be suppressed. As a result, defects such as warping, peeling and cracking can be prevented, and airtightness and oiltightness can be improved. There are advantages.

  In addition, when the width of the terminal part is narrowed to narrow the pitch of the terminal, the shape of the terminal part can be obtained by providing a symmetrical projection on a part of the terminal without reducing the strength of the terminal part. Is symmetrical with respect to the central axis, and there is an advantage that warpage caused by the internal stress distribution of the terminal portion being asymmetric can be suppressed. Moreover, there is an advantage that the terminal part can be prevented from coming off due to an anchor effect by preventing the terminal part from coming out of the sealing resin due to a load in the pulling direction by biting the post-curing convex part into the sealing resin.

1 is a perspective view of an electronic control device for a transmission according to the present invention. It is principal part sectional drawing of the electronic control apparatus for transmissions which concerns on this invention. It is a top view of the electronic controller for transmissions concerning the present invention. It is a top view of the electronic controller for transmissions concerning the present invention. It is a top view of the terminal part of the electronic control unit for transmissions concerning the present invention. It is a top view of the electronic controller for transmissions concerning the present invention.

  Examples will be specifically described below.

  Hereinafter, the best mode for carrying out the present invention will be specifically described by way of examples. However, the present invention is not limited to the following examples.

  FIG. 1 is a perspective view showing an electronic control device for a transmission according to the present invention. FIG. 2 is a cross-sectional view of a main part showing an electronic control device for a transmission according to the present invention. FIG. 3 is a plan view showing an electronic control unit for a transmission according to the present invention.

  As shown in FIG. 1 to FIG. 3, the transmission electronic control device 1 is composed mainly of an electronic component 5, a multilayer wiring board 4, a lead member 2, an adhesive (not shown), and a sealing resin 3. Has been.

  The multilayer wiring board 4 on which the electronic component 5 is mounted is bonded to the lead member 2 having the flange part 21 and the terminal part 22 via an adhesive, and the multilayer wiring board 4 and the terminal part 22 are electrically connected. The flange portion 21 and the terminal portion 22 are partially covered with the sealing resin 3 so as to be exposed.

  The lead member 2 includes a flange portion 21 and a terminal portion 22. The material of the lead member 2 is preferably copper having a high thermal conductivity or a copper-based alloy material. The flange portion 21 is provided so that it can be used for both external fixing and heat conduction path.

  The terminal portion 22 may be a terminal formed by separating a part of the lead member 2 or may be a different member. The exposure direction of the terminal portion 22 may be 1 to 4 directions, but in this embodiment, the exposure direction is exposed in two opposite directions, and the exposure direction is exposed in the lateral direction in order to make the electronic control device 1 thinner. The terminal portion 22 is provided with a symmetrical notch portion 22a. The method of providing the notch 22a can be a cutting process, a laser process, a press process, or the like, but punching with a press is suitable in consideration of processing accuracy, mass productivity, and manufacturing cost.

  After the lead member 2 and the multilayer wiring board 4 are bonded, the terminal portion 22 is electrically connected to the multilayer wiring board 4 via the fine wire 6 by thermocompression bonding, wire bonding, or the like. The thin wire 6 may be made of aluminum, gold, or copper. Nickel plating, silver plating, or the like is partially applied to the surface portion for wire bonding connection of the aluminum thin wires so that the surface is not oxidized. Partial plating for wire bonding connection is performed after surface roughening treatment such as CZ treatment for covalent bonding at the boundary with sealing resin 3, but partial plating for wire bonding connection. If the area is large, the effect of covalent bonding between the lead member 2 and the sealing resin 3 by the surface roughening process is reduced, so that the plating is performed using a mask so that the area becomes the minimum necessary.

  Further, the position where the notch portion 22a is provided may be provided anywhere as long as the terminal portion 22 is buried in the sealing resin. The position is set so as not to interfere with the area of partial plating for wire bonding connection.

  After transfer molding, the tie bar is cut and the terminal portion 22 is separated, and then the sealing resin flows into the cutout portion 22a, and the cured sealing resin bites into the terminal portion after curing. Thus, the notch portion 22a performs an anchoring effect that prevents the terminal portion from coming off the sealing resin. In FIG. 3, although 22 terminal portions 22a are provided from both sides, the number can be increased or decreased according to the system.

  The multilayer wiring board 4 is not particularly limited, and is usually a glass epoxy board using glass fiber and epoxy resin materials, a ceramic board using materials such as alumina, a flexible board using polyimide, etc. Any wiring board used in the apparatus may be used. Moreover, the metal core board | substrate using a metal core layer may be sufficient. The structure of the multilayer wiring board 4 is a through multilayer board that connects circuits between layers by through holes, an IVH multilayer board that connects layers by Interstitial Via Hole (IVH), a build-up multilayer board formed by a build-up method, and the like. May be.

  The electronic component 5 is a mixed mounting of chip components and package components, and is mounted on both sides or one side of the multilayer wiring board 4. The chip component is fixed to the multilayer wiring board 4 with solder or a conductive adhesive by a CPU, a power supply IC, or the like. The electrical connection between the electrode part of the chip component and the multilayer wiring board 4 is performed using the fine wire 6, but flip-chip connection using a solder ball, a gold bump, a conductive adhesive or the like can also be used. The package component is a resistor, a capacitor, a diode, or the like, and is fixed to the multilayer wiring board 4 with solder, but can be fixed using a conductive adhesive. In particular, in the electronic control device 1 that controls a transmission or the like, a relatively large scale circuit in which the number of electronic components 5 exceeds 100 is formed, and a semiconductor device or an integrated circuit having a relatively small size or circuit. It differs from the size of the device. For example, a semiconductor device provided with a heat sink is different from a relatively small device that can absorb warpage due to a difference in linear expansion coefficient between different materials.

  Any adhesive may be used as long as it can fix the multilayer wiring board 4 and the lead member 2, but a thermosetting resin composition such as an epoxy resin or an acrylic resin has a thermal conductivity, stress relaxation, It is suitable in terms of work. When the electronic component 5 is reflowed at the same time as reflow, solder or conductive adhesive can be used. The adhesive is applied to the lead member 2 and the multilayer wiring board 4 is placed at a predetermined position and cured by applying heat. A path for radiating the heat generated by the electronic component 5 to the lead member 2 having high thermal conductivity is formed.

  The sealing resin 3 is manufactured by transfer molding. In the transfer molding, a thermosetting resin such as an epoxy resin is generally used as the sealing resin 3. In particular, a resin having a low coefficient of linear expansion is used to wrap the entire internal part. In addition, the sealing resin 3 is constantly peeled off and disconnected by thermal stress at the soldering portion, the thin wire bonding connection portion between the chip component and the multilayer wiring board 4 in order to maintain the adhesive force with the internal components. The optimum physical property value is selected so as not to occur.

  In the electronic control device 1 for transmission, water from each contact interface between the terminal portion 22 of the lead member 2 or the flange portion 21 and the sealing resin 3 exposed from the sealing resin 3 due to repeated thermal stress during use. Since there is concern about the intrusion of oil, etc., the difference in the linear expansion coefficient between the lead member 2 and the sealing resin 3 is made as small as possible, and the exposed cross-sectional area of the flange portion 21 and the terminal portion 22 is reduced. The lead member 2 is subjected to surface roughening treatment such as CZ treatment, and is covalently bonded at the boundary portion with the sealing resin 3. For example, in a single-sided mold structure using a heat sink, the transmission electronic control device 1 having a large circuit scale and a relatively large external size increases the exposed cross-sectional area and the area of the interface, and therefore, the difference in linear expansion coefficient between different materials. Warp, delamination and cracks occur due to thermal stress caused by, and airtightness and oiltightness are impaired.

  The completed transmission electronic control device 1 is fixed and electrically connected to a wiring member having a structure in which the bus bar 7 is insert-molded with the resin 8. As for the connection method, the terminal portion 22 and the bus bar 7 are connected mainly by laser welding so as to ensure connection reliability even in an environment exposed to corrosive oil.

  According to the present embodiment, a part of the terminal is provided with a left-right symmetric notch, so that the shape of the terminal is symmetric with respect to the central axis, and the internal stress distribution of the terminal is asymmetrical. Warpage can be suppressed. In addition, the terminal with anchor effect prevents the terminal part from coming out of the sealing resin due to a load in the pulling direction by the sealing resin flowing into the notch and the cured sealing resin biting into the terminal part after curing. The part can be prevented from coming off.

  FIG. 4 is a plan view showing an electronic control unit for a transmission according to the present invention. The notch portion 22 b of the terminal portion 22 exists so that a part of the notch portion 22 b is exposed from the sealing resin 3. The ratio at which the notch 22b is exposed is not particularly specified, but the portion where the cross-sectional area on the side buried in the sealing resin changes serves to prevent the terminal portion from coming out of the sealing resin 3 due to a load in the tensile direction. Therefore, the distance from the surface of the sealing resin 3 to the portion where the cross-sectional area changes is a distance that can have a thickness sufficient to achieve the anchor effect.

  After the completion of the transmission electronic control device 1, the terminal portion 22 and the bus bar 7 are connected mainly by laser welding, but the cutout portion 22 b exposed from the sealing resin has the largest cross-sectional area at the terminal portion 22. Since it is small, the notch 22b can play a role of absorbing external force applied during welding.

  According to the present embodiment, by partially exposing the notch portion of the terminal portion from the sealing material, the cross-sectional area of the terminal portion is reduced at the boundary between the portion buried in the sealing resin and the exposed portion, thereby By reducing the area of the interface between different materials, the thermal stress caused by the difference in linear expansion coefficient can be suppressed. As a result, defects such as warpage, peeling and cracking can be prevented, and the air tightness and oil tightness can be improved.

  FIG. 5 is a plan view showing a terminal portion of the electronic control device for a transmission according to the present invention. The cutout shape of the terminal portion 22 may be any of a semicircular cutout portion 22c, a triangular cutout portion 22d, a trapezoidal cutout portion 2e, and a rectangular cutout portion 22f. The number of notches in the terminal portion 22 may be a plurality of notched portions 22g as long as they are arranged symmetrically.

  According to the present embodiment, the shape of the notch is not limited to a specific shape, and therefore can be selected from the viewpoints of processing accuracy, mass productivity, manufacturing cost, and the like. In addition, when a plurality of cutout portions 22g are provided, even if each cutout is small, the sealing resin flows into each cutout portion, and a sufficient anchor effect can be exhibited. It is possible to prevent the strength of the terminal portion 22 from being reduced due to the reduction in the cross-sectional area due to the notch.

  FIG. 6 is a plan view showing an electronic control unit for a transmission according to the present invention. The terminal portion 22 is made as narrow as possible to narrow the pitch. The terminal portion 22 includes a symmetrical convex portion 22h in a part thereof. Although the method of providing the convex part 22h can take methods, such as cutting, a laser processing, and press processing, the punching by a press is suitable considering a processing precision, mass-productivity, and manufacturing cost. Further, the position where the convex portion 22h is provided may be provided anywhere as long as the terminal portion 22 is buried in the sealing resin.

  According to this embodiment, in order to reduce the pitch of the terminal, in the terminal made as thin as possible, by providing a symmetrical projection on a part of the terminal, without reducing the strength of the terminal part, The warpage caused by the shape being symmetric with respect to the central axis and the internal stress distribution of the terminal portion being asymmetric can be suppressed. Moreover, since the convex part after hardening bites into the sealing resin, the terminal part can be prevented from coming off due to the anchor effect, which prevents the terminal part from coming off the sealing resin due to a load in the pulling direction.

DESCRIPTION OF SYMBOLS 1 Electronic control apparatus 2 for transmissions Lead member 3 Sealing resin 4 Multilayer wiring board 5 Electronic component 6 Fine wire 7 Bus bar 8 Resin 21 Flange part 22 Terminal part 22a Symmetrical notch part 22b It exposes from sealing resin Symmetrical notch 22c Semi-circular notch 22d Triangular notch 22e Trapezoidal notch 22f Rectangular notch 22g A plurality of notched parts 22h

Claims (5)

A multilayer wiring board on which electronic components are mounted is bonded to a base member having a flange part and a terminal part via an adhesive, and the multilayer wiring board and the terminal part are electrically connected with a thin wire, and the flange part In an electronic control device for a transmission covered with a sealing material so as to expose a part of the terminal portion,
An electronic control device for a transmission, wherein a part of the terminal covered with the sealing material is provided with a substantially symmetrical notch. In claim 1,
An electronic control device for a transmission, wherein a part of the notch is exposed from a sealing material. In claim 1 or 2,
The electronic control device for a transmission, wherein the notch is semi-circular, triangular, trapezoidal or rectangular. In any one of Claim 1 to 3,
An electronic control device for a transmission, comprising a plurality of the notches. A multilayer wiring board on which electronic components are mounted is bonded to a base member having a flange part and a terminal part via an adhesive, and the multilayer wiring board and the terminal part are electrically connected with a thin wire, and the flange part In an electronic control device for a transmission covered with a sealing material so as to expose a part of the terminal portion,
An electronic control device for a transmission, comprising a convex portion that is substantially symmetrical to a part of the terminal.

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