The present invention relates to an electronic control device such as an engine control unit and an automatic transmission control unit used for an automobile, and particularly to a casing structure of the electronic control device.
With the background of environmental and energy problems, the trend of automobile electronics is accelerating, and the number of electronic control devices installed has been greatly increasing. This leads to limitation of installation space for the electronic control devices, and thus, the electronic control devices are inevitably installed in an engine compartment with severe environmental conditions compared with other locations of an automobile. On the other hand, with a trend of an expanded cabin space to achieve enhanced comfortability of an automobile, the engine compartment has been downsized. This necessitates arrangement of a large number of electronic control devices and wire harnesses in a downsized engine compartment, leading to a difficulty in layout, an increase in weight, and increase in cost. This generates a demand for an electronic control device that is smaller, lighter, and lower in cost. In addition, the wire harness tends to be shortened. This results in, for example, installation of the engine control device at a position closer to the engine, leading to a concern about an influence of high heat and high vibration of the engine on the engine control device. To cope with this, there is a need to enhance heat resistance and vibration resistance of the electronic control device. As a countermeasure, there is a known structure in which a control substrate on which electronic components are mounted is sealed with resin (see PTL
An electric and electronic module described in PTL 1 includes an electronic circuit board on which an electronic circuit is mounted and a metal base for mounting the electronic circuit board, and the electronic circuit board is sealed with a resin.
PTL 1: JP 2007-273796 A
Unfortunately, however, PTL 1 makes no particular consideration regarding the number of components and reliability of connector terminals for external connection at the time of performing resin-sealing on an electronic circuit board.
In particular, an engine control device in recent years has more and more numbers of connector circuits along with enhancement in functions to be compatible with fuel consumption enhancement, leading to increased ratios of dimensions and costs of connectors within downsized engine control devices.
This makes it a problem to provide an electronic control device excellent in productivity and reliability with low cost.
In order to solve the above-described problem, an electronic control device according to the present invention includes: an electronic component; a control substrate on which the electronic component is mounted; a sealing resin for sealing the control substrate; a fixing member at least a portion of which is sealed with the sealing resin; a terminal for providing electrical connection between the control substrate and an external device; and a fixing plate for positioning and fixing the terminal with respect to the fixing member.
According to the present invention, in a case where a circuit board of an electronic control device is sealed with a resin, it is possible to reduce the cost of a connector for external connection while achieving reliability.
Hereinafter, a configuration and an assembly procedure of an electronic control device according to specific embodiments of the present invention will be described with reference to the accompanying drawings.
As illustrated in
As illustrated in
With the fixture for vehicle mounting 9 integrally molded with the housing case 3, heat dissipated from the electronic component 1 towards the housing case 3 such as the heat sink 7 enables enhanced heat dissipation amount to the vehicle body via the fixture for vehicle mounting 9.
As illustrated in FIGS. 2B1 and 2B2, the connector 4 is formed by fabricating a connector unit assembly 12 constituted with a terminal 10 for connecting a vehicle-side harness with the control substrate 2, and a fixing plate 11 for aligning and holding the terminals 10 at a prescribed pitch. The fixing plate 11 includes pins 13 for increasing insertability into the housing case 3 to be described below and for facilitating positioning. The number of the pins 13 is preferably two or more. The material of the terminal 10 may preferably be copper or a copper alloy from the viewpoint of conductivity, downsizing, and cost. The material of the fixing plate 11 may preferably be a polybutylene terephthalate (PBT) resin, a polyamide (PA) 66 resin, and a polyphenylene sulfide (PPS) resin from the viewpoint of light weight and excellent heat resistance.
Subsequently, as illustrated in
When the position of the connector unit assembly 12 with respect to the housing case 3 as a fixing member is determined, tips of the pins 13 protruding from the housing case 3 are fixed by thermal caulking as illustrated in
After the connector unit assembly 12 is fixed, the control substrate 2 on which the electronic component 1 such as a microcomputer is mounted is assembled to the die casting case 3 as illustrated in
A resin wiring board based on glass epoxy resin or the like is used as the control substrate 2. In connecting the electronic component 1 to the control substrate 2, a lead-free solder such as Sn—Cu solder, Sn—Ag—Cu solder, and Sn—Ag—Cu—Bi solder is applied. By setting the control substrate 2 on a substrate receiving unit 16 of the housing case 3, the position in a height direction is determined, and subsequently the control substrate 2 is fixed to the housing case 3 using screws (not illustrated). The number of fixation points by screws may preferably be three or more. In connecting the terminal 10 of the connector unit assembly 12 with the control substrate 2, a lead-free solder such as Sn—Cu solder, Sn—Ag—Cu solder, and Sn—Ag—Cu—Bi solder is applied to a through hole portion 17 of the control substrate 2, into which the terminal 10 is inserted, so as to achieve connection. Note that the type of the connector 4 may be a surface mounting type or a press fit type.
What is important here is a method of fixing the connector unit assembly 12. Specifically, in a case where the connector unit assembly 12 is fixed to the control substrate 2 instead of the housing case 3, the positioning pin 13 is to be inserted into the control substrate 2. This would generate a need to provide a penetration hole for the positioning pin 13 on the control substrate 2, and increase the substrate area correspondingly. In addition, in a case where the terminal 10 of the connector unit assembly 12 and the through hole portion 17 of the control substrate 2 are joined with each other by soldering, the connector unit assembly 12 and the control substrate 2 individually expand and contract due to a thermal history by solder joining, leading to individual deformation. In this process, however, there is a difference in the amount of expansion and contraction between the connector unit assembly 12 and the control substrate 2, leading to generation of warping in the connector unit assembly 12 and the control substrate 2 after joining them, with respect to an original shape of the control substrate 2 indicated by the broken line as illustrated in
In a case where the connector unit assembly 12 and the control substrate 2 in which the warping is generated are fixed to the housing case 3, placing one end 31 of the control substrate 2 on the substrate receiving unit 16 would generate a gap 33 corresponding to the amount of warping at the other end of the control substrate 2 as illustrated in
To cope with this problem, as described in the embodiment, the method of fixing the connector unit assembly 12 may preferably include first fixing the connector unit assembly 12 to the housing case 3, and thereafter joining the terminal 10 of the connector unit assembly 12 to the through hole portion 17 of the control substrate 2. With this method, it is possible to suppress the warping of the connector unit assembly 12 and the control substrate 2, and also to suppress stress generated at the joint portion between the terminal 10 and the through hole portion 17.
As illustrated in
For the purpose of ensuring the fluidity of the sealing resin 5 and enabling the resin to fill over narrower sites inside of the mold, it is preferable to preheat the mold, the sub-assembly, and the resin. The sealing resin 5 may be a thermosetting epoxy resin, an unsaturated polyester resin, or a thermoplastic resin. Examples of sealing methods include transfer molding, compression molding, injection molding, and hot melt. Physical property values of the sealing resin 5 are desirably such that the linear expansion coefficient is 10 to 30×10−6/° C., the thermal conductivity is 0.5 to 3 W/mK.
After completion of resin filling into the mold, the sealing resin is cured in the mold. After curing, the mold is opened and the resin molded product is taken out to complete fabrication of the electronic control device illustrated in
Note that a rising portion 22 on the outer periphery of the housing case excluding the fixture for vehicle mounting 9 is preferably covered with the sealing resin 5. This configuration increases the contact area between the housing case 3 and the sealing resin 5, making it possible to enhance waterproof/anti-saline reliability. Since this configuration further enables reduction of expansion and shrinkage of the housing case 3, it is possible to enhance waterproof and anti-saline reliability and solder connection reliability.
In addition, it is further preferable to cover the thermal caulking portion of the connector terminal fixing plate 11 with the sealing resin 5. This makes it possible to suppress deterioration of the thermal caulking portion and suppress entry of water and salt water from the thermal caulking portion.
Finally, it is more preferable that a housing 21 of the connector 4 is also integrally molded with the sealing resin 5. This can omit necessity to provide the connector housing as a separate component, leading to reduction of the number of components, and probably leading to cost reduction and productivity enhancement.
The configuration of a second embodiment will be described in comparison with the first embodiment. While the first embodiment is a case where the fixing plate 11 is fixed to the housing case 3 by thermal caulking, the second embodiment uses a structure in which the fixing plate 11 is fixed by a snap fit 26 as illustrated in
The configuration of a third embodiment will be described in comparison with the first embodiment. While the first embodiment is a case where the fixing plate 11 is fixed to the housing case 3 by thermal caulking, the second embodiment uses a structure in which the fixing plate 11 is fixed by a screw 27 as illustrated in
The configuration of a fourth embodiment will be described in comparison with the first embodiment. While the first embodiment is a case where the connector unit assembly 12 is fixed to the housing case 3, the fourth embodiment uses a connector 40 with a housing separately from the sealing resin 5 as illustrated in
As above, embodiments of the control device according to the present invention have been described. The present invention is not limited to the above-described embodiments but may include various design modifications without departing from the spirit according to the present invention described in claims.
Number | Date | Country | Kind |
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2015-190620 | Sep 2015 | JP | national |
Filing Document | Filing Date | Country | Kind |
---|---|---|---|
PCT/JP2016/073033 | 8/5/2016 | WO | 00 |
Publishing Document | Publishing Date | Country | Kind |
---|---|---|---|
WO2017/056728 | 4/6/2017 | WO | A |
Number | Name | Date | Kind |
---|---|---|---|
5934913 | Kodama | Aug 1999 | A |
6285551 | Brandenburg et al. | Sep 2001 | B1 |
6307749 | Daanen et al. | Oct 2001 | B1 |
6739893 | Hallitschke | May 2004 | B2 |
6755677 | Kamiya | Jun 2004 | B2 |
7149089 | Blasko | Dec 2006 | B2 |
7209367 | Nakano | Apr 2007 | B2 |
7697300 | Brandt | Apr 2010 | B2 |
8292639 | Achammer | Oct 2012 | B2 |
8872242 | Hayashi | Oct 2014 | B2 |
8962999 | John | Feb 2015 | B2 |
9320165 | Gruber | Apr 2016 | B2 |
9480143 | Washeleski | Oct 2016 | B2 |
9545020 | Kanzaki | Jan 2017 | B2 |
20050122694 | Kane | Jun 2005 | A1 |
20060012034 | Kadoya et al. | Jan 2006 | A1 |
20060281230 | Brandenburg et al. | Dec 2006 | A1 |
20180222408 | Shigyo | Aug 2018 | A1 |
Number | Date | Country |
---|---|---|
1123515 | May 1996 | CN |
2004-362928 | Dec 2004 | JP |
2006-190725 | Jul 2006 | JP |
2007-273796 | Oct 2007 | JP |
2010-62220 | Mar 2010 | JP |
2010-170728 | Aug 2010 | JP |
2014-15080 | Jan 2014 | JP |
2014-53382 | Mar 2014 | JP |
Entry |
---|
International Search Report (PCT/ISA/210) issued in PCT Application No. PCT/JP2016/073033 dated Nov. 29, 2016 with English-language translation (three (3) pages). |
Japanese-language Written Opinion (PCT/ISA/237) issued in PCT Application No. PCT/JP2016/073033 dated Nov. 29, 2016 (three (3) pages). |
Japanese-language Office Action issued in counterpart Japanese Application No. 2017-542991 dated Jan. 8, 2019 with English translation (five (5) pages). |
Extended European Search Report issued in counterpart European Application No. 16850905.7 dated Apr. 17, 2019 with English translation (eight (8) pages). |
Number | Date | Country | |
---|---|---|---|
20180288888 A1 | Oct 2018 | US |