JP2014046776A - On-vehicle electronic control device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To easily provide an on-vehicle electronic control device having inexpensive structure, which is free from exfoliation of encapsulating resin by suppressing thermal stress and warpage arising in a resin-encapsulated on-vehicle electronic control device.SOLUTION: The on-vehicle control device comprises: a wiring board on which conductor wiring is formed; electronic components mounted on the first surface of the wiring board; a lead frame which inputs and outputs external signals and is mounted on the second surface of the wiring board. The on-vehicle control device is resin-encapsulated with a resin composition 1 which so covers the first surface of the wiring board as to cover the electronic components and a resin composition 2 which so covers the second surface of the wiring board as to cover at least a part of the lead frame. The coefficient of linear expansion or the mold shrinkage factor of the resin composition 2 is larger than that of the resin composition 1.

Description

The present invention relates to a technology for resin-sealing an electronic circuit board on which semiconductor elements and electronic components are mounted, and in particular, a large circuit board on which a plurality of semiconductor elements and electronic parts are mounted as in a vehicle-mounted control device. The present invention relates to a resin sealing structure of an in-vehicle electronic control device that is resin-sealed to a target.

Conventionally, an in-vehicle electronic control device has been installed in a vehicle interior. However, as the number of electronic control devices installed in a single vehicle increases, the installation location changes from the vehicle interior to the engine room or the mission. It is supposed to be installed in.

  However, in the engine room and the mission, the use environment such as heat resistance, water resistance, vibration resistance, etc. becomes severer than the use environment in the conventional vehicle interior. It is done.

For example, the reliability test for measuring the product life of in-vehicle control devices is generally a thermal shock test up to around 1000 cycles with -40 ° C to 120 ° C for 1 hour each, but 2000 cycles. The product life is required up to 3000 cycles.

As one of the means to improve reliability, we apply resin molding technology by transfer mold, which is generally established as resin sealing technology for semiconductor packages, to electronic control devices with large circuit boards such as ECU and ATCU. It is known that heat resistance, water resistance, vibration resistance and the like can be improved by resin-sealing the entire surface of the substrate.

  Since the resin-sealed electronic control device is completely covered with resin, it can be protected from the external environment such as moisture and gas.

Furthermore, since the connection part of the semiconductor element or electronic component, the connection part of the conductive paste or the wire bonding or the like is completely restrained by the resin, distortion due to mechanical vibration or distortion applied to the connection part due to a temperature difference. Since this leads to an increase in the connection life and high reliability.

  An ECU or ATCU is a structure made of a combination of different materials, and each structural member thermally contracts depending on the value of the linear expansion coefficient of each material. The thermosetting resin used in the transfer mold undergoes molding shrinkage that combines curing shrinkage associated with a chemical curing reaction during resin molding and thermal shrinkage due to a material-specific linear expansion coefficient.

Therefore, warpage occurs due to the difference between the thermal shrinkage of the structural members constituting the ECU and ATCU and the molding shrinkage of the resin. At this time, tensile stress acts on the adhesive interface of the resin, and the member is broken or the resin is peeled off from the interface where the adhesive strength of the resin is weak. If the resin adhesion on the resin bonding surface occurs between the electronic circuit board and the external environment, the electronic circuit board will come into contact with the external environment. There is a concern that breakage between circuit wirings due to intrusion may occur. Therefore, the resin-sealed electronic control device should not have resin peeling at the resin bonding interface.
Since the generation of thermal stress that causes resin peeling is affected by the type and thickness of the constituent members and the resin, the optimal combination of materials is not uniform, and an optimal material design according to the application is required.

  Patent Document 1 discloses an invention of an automotive electronic circuit in which resin peeling does not occur due to thermal stress. A silicon bare chip is used as an electronic circuit element, a ceramic substrate is used as a circuit board, and a clad material in which an Invar alloy (iron 64% -36% by weight) and copper are laminated on a lead frame is used. The structure which reduces the thermal stress which generate | occur | produces by the difference of a linear expansion coefficient by using is disclosed.

Patent Document 2 describes a configuration that uses a flexible flexible circuit board to match the apparent expansion coefficients of the circuit board and the lead frame, and suppresses the occurrence of excessive stress between the two, in order to suppress resin peeling. Is disclosed.

JP 2007-43196 A Japanese Patent Laid-Open No. 2004-95974

  However, the circuit board targeted by the invention of Patent Document 1 is a ceramic board, which is very expensive compared to a resin printed board, and the lead frame is also laminated with Invar alloy and copper in order to match the linear expansion coefficient. Special clad material was used.

In the structure of Patent Document 2, the flexible substrate itself is more expensive than a resin printed substrate made of general-purpose glass epoxy.

As described above, in order to match the linear expansion coefficient between materials using a silicon bare chip, a circuit board, and a lead frame, it is necessary to use an expensive material or a special material.

As a result of various studies of resin-sealing an electronic control device comprising a lead frame using a silicon bare chip, an inexpensive resin printed circuit board, and a general copper alloy, the resin printed circuit board itself is easily warped. There was a problem that bare chip element failure and further resin peeling occurred due to thermal stress.

  The above-described problem is solved by making the linear expansion coefficient of the resin composition 2 larger than the linear expansion coefficient of the resin composition 1 in the resin-sealed on-vehicle electronic control device.

In addition, in the vehicle-mounted electronic control device sealed with resin, the problem is solved when the molding shrinkage rate of the resin composition 2 is larger than the molding shrinkage rate of the resin composition 1.

ADVANTAGE OF THE INVENTION According to this invention, the vehicle-mounted electronic control apparatus which does not produce peeling of sealing resin by suppressing the thermal stress and curvature which generate | occur | produce in the resin-mounted vehicle-mounted electronic control apparatus can be provided easily by an inexpensive structure.

It is a figure explaining the curvature of an electronic controller, and the thermal contraction of resin, (a) is before resin sealing, (b) is a partial sectional view after resin sealing. The external view which is an example of the electronic control apparatus of this invention, and shows the one part inside of a resin composition. It is sectional drawing which shows a part of inside of the electronic control apparatus of this invention. It is a schematic diagram explaining a transfer mold construction method. It is an example after resin sealing of the electronic control apparatus of this invention, (a) Top view, (b) Front view, (c) Bottom view. FIG. 3 is a partial cross-sectional view showing a resin molding process of the electronic control device of the present invention, and shows a state in which resin composition 1 and resin composition 2 melted in a mold are filled. FIG. 3 is a partial cross-sectional view illustrating a difference in resin flow length between resin composition 1 and resin composition 2. It is an external view which shows an example of the lead frame of the electronic controller of this invention. 2 is a partial cross-sectional view showing resin heights of resin composition 1 and resin composition 2. FIG. 5 is a cross-sectional view showing a part of the inside of an electronic control device of Comparative Example 1. FIG. The table for demonstrating a comparative example.

(Example 1)
Hereinafter, an electronic control device mounting structure according to the present invention will be described with reference to the drawings. First, a first embodiment according to the present invention will be described with reference to FIG. 2, FIG. 3, and FIG. The electronic control device of the present invention is an example of an ATCU installed in a transmission, and captures information of other control units by input signals from various sensors, input switch states, and CAN communication according to the vehicle running state. Then, by controlling a plurality of solenoids, an appropriate vehicle running state is realized by performing AT speed change and hydraulic pressure adjustment.

  FIG. 2 is an example of the electronic control device of the present invention, and is an external view showing a part of the interior of the resin composition. FIG. 3 is a cross-sectional view showing a part of the inside of the electronic control device of the present invention.

  The configuration of the present invention includes a wiring board 3 on which conductor wiring is formed, a semiconductor bare chip 7 and package component 8 mounted on the first surface of the wiring board, and an external mounted on the second surface of the wiring board 3. A lead frame 4 for inputting and outputting signals; a resin composition 1 that covers the first surface so as to cover an electronic component; and a resin composition 2 that covers a second surface so as to cover at least a part of the lead frame; Consists of.

  Wiring board 3 is a resin printed circuit board that has a larger coefficient of thermal expansion than ceramic and metal boards, and epoxy cloth is impregnated in glass cloth that is currently widely distributed for both consumer and industrial use. FR4 copper-clad laminate is used. The wiring board 3 is a build-up board composed of a plurality of layers, and the board thickness is preferably 2.0 mm or less. Although not shown in FIG. 2, electronic components such as a chip resistor 8a, a chip capacitor 8b, an oscillator 8c, and a diode 8d are connected to the wiring board 3 by a solder reflow process.

  In this case, it is preferable to use lead-free solder as the solder paste to be used. This is because when the resin sealing is performed by transfer molding, the resin molding temperature is about 180 ° C., and therefore, eutectic solder having a low melting point may cause the solder to remelt during resin molding.

  Subsequently, a semiconductor element such as an unpackaged bare chip microcomputer 7a and a power IC (not shown) constituting a constant voltage power supply circuit is bonded to a silver paste as a conductive paste. The wiring board 3 and the bare chip 7 are electrically joined by wire bonding of gold wires 9.

The silver paste is used for the bonding member between the bare chip 7 and the wiring board 3 because the soldering flux or solder balls are scattered on the bonding pad for bonding the gold wire 9 so that the bonding failure of the bonding of the gold wire 9 does not occur. Because. Since bare chip mounting enables high-density mounting rather than using packaged components, the electronic control device of the present invention has high-density mounting with a component mounting rate exceeding 70%. Therefore, the bonding pads of the gold wire 9 are also very narrow pitch, and in order to secure bonding properties, a conductive paste is more suitable than solder, but depending on the desired mounting form, can the solder and the conductive paste be used properly? Alternatively, either one may be used.

  FIG. 8 is an external view showing an example of the lead frame 4 of the electronic control device of the present invention. The lead frame includes an island portion 4a on which the wiring board 3 is mounted and a terminal portion 4b for electrical connection to the outside. The island portion 4a and the terminal portion 4b are connected by a connection portion 4c. This lead frame 4 is manufactured by integrally punching a plate material by a cold press, and the entire surface is roughened by a chemical etching process to improve the adhesion to the resin. The material of the lead frame is a general copper alloy having a composition of 95% by weight or more of copper.

  A part of the terminal portion 4b for electrical connection is subjected to Ni plating for bonding the aluminum wire 6.

  The lead frame 4 and the wiring board 3 are bonded in advance by an adhesive agent 10, and the adhesive agent 10 is made of a thermosetting epoxy resin. By fixing the wiring board 3 and the lead frame 4 in advance with the adhesive 12, warpage during transfer molding is suppressed, and the bonding property of the aluminum wire 6 is secured thereafter. The adhesive member 10 has an elastic modulus of about 3 GPa at room temperature, and is a low elastic resin compared to the elastic moduli of the resin compositions 1 and 2. This is because the adhesive member 10 acts as a buffer material to suppress thermal stress applied to the wiring board 3 and the lead frame 4.

The thickness of the bonding member 10 is 200 μm or less, and it is desirable that the bonding range be uniformly applied to the entire bonding surface of the wiring board and the lead frame without a gap. If there is a gap, the resin composition at the time of subsequent transfer molding is not filled in the gap, and resin voids are easily formed and the resin is easily peeled off starting from the gap.

The lead frame 4 on which the wiring board 3 is mounted by the adhesive member 10 is left in a thermostatic bath at 150 ° C. for 1 hour and cured sufficiently, and then the wiring board 3 and the terminal part 4b of the lead frame are bonded by bonding of the aluminum wire 6. Are electrically connected. Thus, the electronic circuit assembly 50a before resin sealing is completed.

  Next, transfer molding is performed using the resin composition 1 and the resin composition 2. It is preferable to perform plasma cleaning before transfer molding. The plasma cleaning is effective in removing the resist oxide film on the surface of the wiring board 3 and the like that inhibits the adhesion with the resin composition 1. In particular, the resist on the surface of the wiring board 3 is significantly oxidized by heat of 250 ° C. or more due to the previous solder reflow process.

In this embodiment, argon plasma treatment is performed before wire bonding of the gold wire 9 and before wire bonding of the aluminum 6.

Resin composition 1 and resin composition 2 formed by transfer molding are tablets that are solid at room temperature before molding, and are mainly composed of an epoxy resin, a curing agent, and a filler (filler). This tablet is a thermosetting resin composition in which a resin powder is preheated and formed into a tablet shape while being pressed, and melts when it is heated at 180 ° C. to start curing.

  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. However, a biphenyl type epoxy resin having a low melt viscosity and high adhesiveness is optimal.

  Moreover, as a hardening | curing agent, if it has a functional group which hardens | cures an epoxy resin, it will not specifically limit. For example, there are aliphatic or aromatic amine compounds, phthalic anhydride, acid anhydrides, phenolic resins such as phenol novolac, polyamides, modified polyamines, imidazoles, etc., but phenolic resins with low molecular weight and low melt viscosity are desirable. . The reason why a lower melt viscosity is better is that a resin having a low melt viscosity has good resin flowability at the time of molding and resin molding defects are less likely to occur. Moreover, if the melt viscosity is high, it may cause the wire bonding or the like on the wiring board to flow or bend during resin flow. In general, the melt viscosity of the resin is preferably 100 Pa · s or less.

  Resin compositions 1 and 2 may be epoxy resins having the same skeleton and different types of curing agents, but are the same skeleton epoxy resin and the same type of curing agent from the viewpoint of moldability and the like. It is preferable.

  Furthermore, the epoxy resin can contain a stress-reducing material such as silicone rubber or oil or butadiene-based rubber in order to reduce the stress by reducing the elastic modulus.

  As the filler, at least one kind of horny (crushed) or spherical shape such as fused silica, crystalline silica, alumina, boron nitride, magnesium hydroxide, which is an inorganic substance, can be used. Since the physical property values such as linear expansion coefficient and heat dissipation are different from each other, the filler may be selected so as to obtain a desired physical property value, but silica that is generally widely used as a filler may be cheap.

  In addition to the above components, the resin composition used in the present invention may contain a curing accelerator, a release material, a colorant, a flame retardant, and the like as necessary.

  The filler amount of the resin composition 1 is 70% by volume, and the filler shape is all spheres (all spheres). The filler amount of the resin composition 2 is 60% by volume, and the filler shape is a mixture of spherical and square shapes in a ratio of 7 to 3.

The reason why only the resin composition 1 has the entire filler shape is to reduce the damage to the bare chip 7 and the damage to the gold wire 9 by the square filler as much as possible. Therefore, the resin for resin-sealing the electronic control device on which the bare chip 7 is mounted preferably has a global filler shape, but the cost of using the global filler shape is increased. Therefore, the resin composition 1 that covers the mounting surface of the bare chip 7 has a spherical filler shape, and the resin composition 2 that covers a portion that is not the mounting surface of the bare chip has a spherical / square mixed filler shape. Cost increase can be minimized without damaging 9

  The linear expansion coefficient α1 before the glass transition temperature after the resin composition 1 is cured is 13 ppm / ° C., and the linear expansion coefficient α2 after the glass transition is 49 ppm / ° C. The linear expansion coefficient α1 before the glass transition temperature after the resin composition 2 is cured is 16 ppm / ° C., and the linear expansion coefficient α 2 after the glass transition is 60 ppm / ° C.

The molding shrinkage rate of the resin composition 1 is 0.38%, and the molding shrinkage rate of the resin composition 2 is 0.52%. The molding shrinkage rate was measured by the measurement method defined in 5.7 in JISK6911-1995.

  Fig. 4 shows a schematic diagram of the transfer mold method. The electronic circuit assembly 50a is set in the upper mold 30 and the lower mold 40 set at 180 ° C., and the mold is clamped with a force of several tens of tons (4-1).

  The resin tablets 32 of the resin composition 1 and the resin composition 2 are set, and the resin 32 melted in the mold is pushed out by the plunger 31 and filled into the mold (4-2).

  After filling the resin, the molding pressure of 7 MPa is applied to the resin in the mold to cure the resin (4-3).

And a step (4-4) of opening and releasing the mold after molding.

  FIG. 5 is an example after transfer molding of the electronic control device of the present invention, (a) a top view, (b) a front view, and (c) a bottom view. The mold is provided with a runner and gate for injecting resin composition 1 and resin composition 2. By dividing the resin injection location into two parts, resin composition 1 and resin composition 2 are transfer molded. Is integrally molded with resin.

  To provide two runners and a gate, use a multi-pot molding machine that has multiple pots into which resin tablets are placed, and configure the mold so that each pot connects to one of the two runners. That's fine.

  Therefore, after the transfer molding, the runner part 11 and the gate part 12 of the resin composition 1, and the runner part 13 and the gate part 14 of the resin composition 2 remain as extra resin parts. Finally, after resin molding, these excess resin portions are cut and resin deburred, and the lead frame connecting portions 4c are cut to obtain the electronic control device of the present invention shown in FIG.

  After transfer molding, after-curing was performed at 140 ° C. for 12 hours in order to completely cure the sealing resin.

  Normally, after-cure at 180 ° C for about 5 hours is recommended, but considering the thermal stress on the resin printed circuit board, the temperature was lowered to 140 ° C and the cure time was extended accordingly. The thus-cured sealing resin has the physical properties of the chamber, and it has been confirmed that there is no difference from that after-curing at 180 ° C. for 5 hours.

  FIG. 6 is a partial cross-sectional view showing the resin molding process of the electronic control device of the present invention, and shows a state in which the resin composition 1 and the resin composition 2 melted in the mold are filled. Resin compositions 1 and 2 flow in the form of a so-called fountain flow while melting in the mold. At this time, it is preferable to cause the resin composition 1 and the resin composition 2 to flow so that there is no difference in flow length. FIG. 7 is a partial cross-sectional view showing the flow length difference between the resin composition 1 and the resin composition 2. If there is a difference in flow length as shown in FIG. 7 (b) or FIG. 7 (c), the resin printed circuit board or the lead frame may be warped, and stress is applied to the mounted electronic components. Therefore, the resin flow having no flow length difference shown in FIG. 7 (a) is ideal.

  The flow length difference can be confirmed by performing a short shot (not completely filled with the resin composition) that stops the position of the plunger halfway. The difference in flow length is caused by various causes such as the melt viscosity of the resin, molding conditions, gate shape and gate position, but the resin height has the most influence on the flowability of the resin.

  FIG. 9 is a partial cross-sectional view showing the resin heights of Resin Composition 1 and Resin Composition 2.

  The flowing resin is easy to flow where the height of the resin is high, and it is difficult to flow where the resin is low. Therefore, the height t of the resin composition 1 and the resin height L of the resin composition 2 were determined as follows.

  The resin height (t) of the resin composition 1 may be determined by the height of the electronic component to be mounted, and it is appropriate that it is more than 0.5 mm and about 2 mm from the top of the highest-level component. If the thickness is less than 0.5 mm, problems such as unfilled resin or molding defects such as voids occur. If the thickness exceeds 2 mm, the amount of resin increases extremely and becomes heavy.

  The resin height L of the resin composition 2 is made smaller than the resin height t (t> L). This is due to the following reason. The resin-filled portion of the resin composition 1 has resistance during resin flow because the parts are mounted, so the resin height (t) of the resin composition 1 and the resin height (L) of the resin composition 2 are Equal (t = L), or when the resin height (L) of the resin composition 2 is larger than the resin height (t) of the resin composition 1 (t <L), the resin height is high and the flow resistance is high. This is because the resin flow of the resin composition 2 is accelerated due to a small amount of resin, and a difference in resin flow length occurs.

The electronic control device of the present invention was confirmed that the resin height 1 of the resin composition 1 was 4.0 mm, the resin height L of the resin composition 2 was 2.0 mm, and there was no difference in the resin flow length. According to the mounting form, the resin height may be t> L.

  Using the electronic control device created in this way, the presence or absence of resin peeling or malfunction after 3000 cycles of the thermal shock test was investigated, and the results are shown in Table 1.

  The test conditions of the thermal shock test are as follows. One cycle each from -40 ° C to 120 ° C was examined for the presence of resin peeling or malfunction after 3000 cycles. The resin peeling is investigated using an ultrasonic flaw detection imaging device, and the malfunction is actually operated at three temperatures of low temperature (-40 ° C), normal temperature (20 ° C), and high temperature (120 ° C). The function test was performed and confirmed.

The evaluation of the resin peeling and operation failure was shown by the ratio of the number of defects to the total number of evaluations.

With such a configuration, in a thermal shock test in which each cycle is one cycle at -40 ° C. to 120 ° C., it was confirmed that the electronic control device had a life of 3000 cycles or more and had high reliability.

(Example 2)
The second embodiment according to the present invention has the structure shown in the schematic diagram of FIG.
The difference from Example 1 is that the resin composition 1 has a filler amount of 75% by volume, and the linear expansion coefficient α1 before the glass transition temperature after the resin composition 1 is cured is 10 ppm / ° C., after the glass transition. The linear expansion coefficient α2 is 42 ppm / ° C. The molding shrinkage rate of the resin composition 1 is 0.27%.
Other configurations and manufacturing methods are the same as those in the first embodiment.

Using the electronic control device created in this way, the presence or absence of resin peeling or malfunction after 3000 cycles of the thermal shock test was investigated, and the results are shown in Table 1.

With such a configuration, in a thermal shock test in which each cycle is one cycle at -40 ° C. to 120 ° C., it was confirmed that the electronic control device had a life of 3000 cycles or more and had high reliability.

(Example 3)
The second embodiment according to the present invention has the structure shown in the schematic diagram of FIG.
The difference from Example 1 is that the resin composition 1 has a filler amount of 80% by volume, and the linear expansion coefficient α1 before the glass transition temperature after the resin composition 1 is cured is 8 ppm / ° C., after the glass transition. The coefficient of linear expansion α2 is 35 ppm / ° C. The molding shrinkage rate of the resin composition 1 is 0.18%.
Other configurations and manufacturing methods are the same as those in the first embodiment.

  Using the electronic control device created in this way, the presence or absence of resin peeling or malfunction after 3000 cycles of the thermal shock test was investigated, and the results are shown in Table 1.

With such a configuration, in a thermal shock test in which each cycle is one cycle at -40 ° C. to 120 ° C., it was confirmed that the electronic control device had a life of 3000 cycles or more and had high reliability.

(Comparative Example 1)
FIG. 10 is a cross-sectional view showing a part of the inside of the electronic control device of Comparative Example 1. The difference from Example 1 is that only the resin composition 1 was used and the whole was resin-sealed. The filler amount of the resin composition 1 is 65% by volume, the linear expansion coefficient α1 before the glass transition temperature after the resin composition 1 is cured is 16 ppm / ° C., and the linear expansion coefficient α2 after the glass transition is 60 ppm / ° C. The molding shrinkage rate of the resin composition 1 is 0.52%. Other configurations and manufacturing methods are the same as those in the first embodiment.

Using the electronic control device created as described above, the presence or absence of resin peeling or malfunction after 3000 cycles of the thermal shock test was investigated, and the results are shown in FIG.

In such a configuration, in a thermal shock test in which one cycle is performed at -40 ° C. to 120 ° C. for 1 hour each, there were some that the bare chip cracked and did not operate, and some that the resin was peeled off.

(Comparative Example 2)
The electronic control device of Comparative Example 2 has the structure shown in FIG. The difference from Example 1 is that only the resin composition 1 was used and the whole was resin-sealed. The filler amount of the resin composition 1 is 70% by volume, the linear expansion coefficient α1 before the glass transition temperature after the resin composition 1 is cured is 13 ppm / ° C., and the linear expansion coefficient α2 after the glass transition is 49 ppm / ° C. The molding shrinkage rate of the resin composition 1 is 0.38%. Other configurations and manufacturing methods are the same as those in the first embodiment.

Using the electronic control device created as described above, the presence or absence of resin peeling or malfunction after 3000 cycles of the thermal shock test was investigated, and the results are shown in FIG.

In such a configuration, in a thermal shock test in which one cycle is performed from -40 ° C. to 120 ° C. for 1 hour each, there were some that did not operate and some that had resin peeled off.

(Comparative Example 3)
The electronic control device of Comparative Example 2 has the structure shown in FIG. The difference from Example 1 is that only the resin composition 1 was used and the whole was resin-sealed. The filler amount of the resin composition 1 is 70% by volume, the linear expansion coefficient α1 before the glass transition temperature after the resin composition 1 is cured is 13 ppm / ° C., and the linear expansion coefficient α2 after the glass transition is 49 ppm / ° C. The molding shrinkage rate of the resin composition 1 is 0.39%. Other configurations and manufacturing methods are the same as those in the first embodiment. Using the electronic control device created as described above, the presence or absence of resin peeling or malfunction after 3000 cycles of the thermal shock test was investigated, and the results are shown in FIG.

In such a configuration, in a thermal shock test in which each cycle of one hour from -40 ° C. to 120 ° C. did not work, most of the resin was peeled off at the interface between the lead frame and the resin composition 1.

  Specific examples of the present invention have been described in detail above, but these are merely examples and do not limit the scope of the claims.

The electronic control module mounting structure of the present invention is used as, for example, an in-vehicle ATCU, but may be used for electronic control.

1 Resin composition 1
2 Resin composition 2
3 Wiring board 4 Lead frame 4a Island part 4b Terminal part 4c Connection part 6 Aluminum wire 7 Bare chip 7a Microcomputer 8a Chip resistor 8b Chip capacitor 8c Oscillator 8d Diode 9 Gold wire 10 Adhesive member

Claims (14)

A wiring board on which conductor wiring is formed; and
An electronic component mounted on the first surface of the wiring board;
A lead frame for inputting and outputting external signals mounted on the second surface of the wiring board;
A resin composition 1 covering the first surface so as to cover the electronic component;
An in-vehicle electronic control device resin-sealed with a resin composition 2 that covers the second surface so as to cover at least a part of the lead frame,
An in-vehicle electronic control device, wherein a linear expansion coefficient of the resin composition 2 is larger than a linear expansion coefficient of the resin composition 1.
In claim 1,
The resin composition 1 and the resin composition 2 each contain a filler,
An on-vehicle electronic control device characterized in that at least one of the shape, type and amount of the fillers is different.

In claim 2,
An in-vehicle electronic control device satisfying a relationship of t> L, where t is a resin thickness of the resin composition 1 and L is a resin thickness of the resin composition 2.
In claim 1,
The vehicle-mounted electronic control device, wherein the resin composition 1 and the resin composition 2 are integrally molded by transfer molding.
In claim 1,
The vehicle-mounted electronic control device, wherein the wiring board and the lead frame are fixed by an adhesive member having a lower elastic modulus than the resin composition 1 and the resin composition 2

In claim 1,
The vehicle-mounted electronic control device, wherein the wiring board is a resin printed board.

In claim 1,
The on-vehicle electronic control device according to claim 1, wherein at least one of the electronic components mounted on the wiring board is a bare chip that is not packaged.


A wiring board on which conductor wiring is formed; and
An electronic component mounted on the first surface of the wiring board;
A lead frame for inputting and outputting external signals mounted on the second surface of the wiring board;
A resin composition 1 covering the first surface so as to cover the electronic component;
An in-vehicle electronic control device resin-sealed with a resin composition 2 that covers the second surface so as to cover at least a part of the lead frame,
An in-vehicle electronic control device, wherein a molding shrinkage rate of the resin composition 2 is larger than a molding shrinkage rate of the resin composition 1.

In claim 8,
The resin composition 1 and the resin composition 2 each contain a filler,
An on-vehicle electronic control device characterized in that at least one of the shape, type and amount of the fillers is different.

In claim 9,
An in-vehicle electronic control device satisfying a relationship of t> L, where t is a resin thickness of the resin composition 1 and L is a resin thickness of the resin composition 2.
In claim 8,
The vehicle-mounted electronic control device, wherein the resin composition 1 and the resin composition 2 are integrally molded by transfer molding.
In claim 8,
The vehicle-mounted electronic control device, wherein the wiring board and the lead frame are fixed by an adhesive member having a lower elastic modulus than the resin composition 1 and the resin composition 2

In claim 8,
The vehicle-mounted electronic control device, wherein the wiring board is a resin printed board.

In claim 8,
The on-vehicle electronic control device according to claim 1, wherein at least one of the electronic components mounted on the wiring board is a bare chip that is not packaged.