JP2003249780A - Electronic component mounting structure - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electronic component mounting structure wherein a space for isolating a heating component is formed with a simple structure, and the amount of resin for filling the space can be reduced without deteriorating the heat dissipating property of the heating component. <P>SOLUTION: The electronic component mounting structure is provided with a printed board 2 for mounting electronic components 1a on both surfaces, a case main body 3 for accommodating the printed boards 2 and a case lid 4 for covering the case main body 3. A partition plate 5 for partitioning a space in the case is installed in at least either one of the case main body 3 and the case lid 4. The partitioned spaces communicate with each other, and an electronic component 1b needing heat dissipation is arranged in the partitioned space, which is filled with resin 6. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electronic component mounting structure in which an electronic component mounted on a printed circuit board is embedded by using a resin mold.

2. Description of the Related Art As a conventional example of this kind, Japanese Patent Application Laid-Open No. 9-12
The one disclosed in Japanese Patent No. 9451 is cited. This is shown in Figure 7.
As shown in FIG.
In a high voltage generator having a printed circuit board 20 on which 0 is mounted and a case 10 for housing the printed circuit board 20,
A contact seal portion 70 and partition walls 60 and 61 are provided at the contact portion of the case 10 with the printed circuit board 20, and the partition walls 60 and 61 separate the resin filling chamber 14 and the non-resin filling chamber 16.
Here, on the upper end surface of the partition wall 60, three contact seal portions 70 integrally formed with the case 10 and a fixing rib 90, and a mounting hole into which the fixing rib 90 is inserted and fitted in the printed circuit board 20. A section 25 is provided. With such a configuration, the step-up transformer 40, which is a high temperature heating element, and the electronic component 30, which is a low temperature heating element, are thermally separated.

However, the fixing rib 9
In order to form the 0 and the mounting hole 25 so as to be fitted to each other, precision in the manufacturing process is required, and the yield may be poor. Further, since the entire resin filling chamber 14 is filled with the resin, the filling amount may unnecessarily increase. The present invention is made in view of the above problems,
The purpose thereof is to provide an electronic component mounting structure that can form a space for separating heat generating components with a simple structure and reduce the filling amount of resin filling the space without degrading the heat dissipation performance of the heat generating components. To provide.

According to another aspect of the present invention, there is provided an electronic component mounting structure, a printed board on which electronic components are mounted, a case body for housing the printed board, and a case lid for covering the case body. In the electronic component mounting structure having, at least one of the case main body or the case lid is provided with a partition plate for partitioning the space inside the case, and the partitioned spaces are in communication with each other, and an electronic component requiring heat radiation is provided. It is characterized in that it is arranged in at least one of the divided spaces and the space is filled with resin. In such an electronic component mounting structure, only the heat-generating components that are in the spaces separated by the partition plate and require heat radiation are embedded in the resin. The electronic component mounting structure according to claim 2 is the electronic component mounting structure according to claim 1,
It is characterized in that at least one electronic component that cannot be filled is included. An electronic component mounting structure according to a third aspect is the electronic component mounting structure according to the first or second aspect, characterized in that an electronic component having a heat dissipation plate is filled together with the heat dissipation plate.

1 shows a heat dissipation structure of a heat-generating component according to a first embodiment of the present invention, and FIG. 2 shows an example of a circuit diagram of a discharge lamp lighting device including the heat-generating component. Shows. First, FIG. 1 shows a printed circuit board 2 on which electronic components 1a are mounted on both sides, and a case body 3 for housing the printed circuit board 2.
And a case lid 4 that covers the case body 3, and a partition plate 5 that is provided in the case body 3 and partitions the space inside the case.
The resin 6 that fills the space 7b in which the electronic component 1b that requires heat radiation is arranged, and the spaces 7a and 7b divided by the partition plate 5 are shown. The configuration of each part of the heat dissipation structure will be described below. The electronic component 1a includes the capacitor 2 and switching elements Q2 to Q5 shown in FIG. The printed circuit board 2 has a discrete electronic component mounted on one surface and a chip component (both indicated by 1a) on the other surface. The printed circuit board 2 is provided on the bottom surface side of the case body 3 on the bottom surface of the case body 3. It is stored horizontally. The case body 3 is for accommodating the printed circuit board 2, and has, for example, a box shape with one surface open. Here, the material of the case body 3 is, for example, metal. The case lid 4 covers the opening surface of the case body 3, and the material thereof is, for example, metal. As a material of the case body 3 and the case lid 4, a plastic material or an aluminum die cast may be used in consideration of easiness of processing. The partition plate 5 separates the space inside the case, and is erected substantially vertically on the bottom surface of the case body 3. Here, the space divided by the partition plate 5 is 7
a and 7b, and a heat generating component is arranged in the space 7b. Then, the space 7b is filled with resin.
In the present embodiment, the partition plate 5 is connected to the case body 3. That is, the case body 3 and the partition plate 5 are formed of a single metal plate, which simplifies the manufacturing process. Of course, the case body 3
The partition plate 5 and the partition plate 5 may be separately manufactured and engaged with each other. The height of the partition plate 5 is set lower than that of the side surface of the case body 3. That is, the case body 3 has a case lid 4
The partition plate 5 does not come into contact with the case lid 4 when it is covered. Here, in the present embodiment, since the switching elements Q2 to Q5 operate at a low frequency, the surface temperature does not reach 100 ° C. even when the high pressure discharge lamp LA is turned on. On the other hand, the switching element Q that constitutes the step-down chopper circuit
1 has a large amount of heat generation because it operates at high frequency,
It becomes a high temperature of about 100 to 150 ° C. The electronic component 1b, such as the switching element Q1, in which the high-pressure discharge lamp LA has a high temperature in the normal lighting state is arranged in the space 7b separated by the partition plate 5, as described above. The resin 6 fills the space 7b in which the electronic component 1b having a high temperature is placed, and is made of a material having excellent moisture resistance, vibration isolation, and thermal conductivity. The material is, for example, epoxy resin. The resin 6 is filled at a height that does not exceed the height of the partition plate 5 that is erected substantially vertically on the bottom surface of the case body 3. By filling in this way, the filling amount of resin can be reduced, the weight of the entire discharge lamp lighting device can be reduced, and the cost can be reduced. Next, the discharge lamp lighting device shown in FIG.
And a DC power supply circuit (AC power supply AC; an input filter circuit having a capacitor C1, a filter LF1 and a capacitor C2; and a rectifier circuit D).
B); a voltage conversion circuit (switching element Q1, diode D1 and inductor L1); a smoothing circuit (capacitor C3); a polarity inversion circuit (switching elements Q2 to Q5); a load circuit (inductor L2,
A condenser C5 and a high pressure discharge lamp LA); and an igniter circuit (a condenser C4, a switching element SW and a pulse transformer). The configuration of each part of the discharge lamp lighting device will be described below. The AC power supply AC is a commercial AC power supply and has a voltage of, for example, 100V, 200V, or 240V. The input filter circuit prevents noise from the AC power supply AC from entering the polarity reversing circuit, or conversely prevents noise from the polarity reversing circuit from leaking to the power supply side. Rectifier circuit DB is AC power supply A
The AC voltage from C is rectified into a pulsating voltage and output, and is composed of, for example, a diode bridge. When the voltage of the AC power supply AC is 100 V, a voltage doubler rectifier circuit may be used instead of the diode bridge.
When the voltage doubler rectifier circuit is used, the voltage of the AC power supply AC can be regarded as substantially equal to 200 V, and the current flowing in the circuit connected after the voltage doubler rectifier circuit is about half that in the case where a diode bridge is used. Therefore, the efficiency of the discharge lamp lighting device can be improved. The voltage conversion circuit converts the voltage from the rectifier circuit DB into another voltage, and in the present embodiment, a step-down chopper circuit is adopted.
The capacitor C3, which is a smoothing circuit, smoothes the output voltage of the voltage conversion circuit and is composed of, for example, an electrolytic capacitor. The polarity reversing circuit converts the DC voltage from the capacitor C3 into a rectangular wave voltage by turning on / off the switching elements Q2 to Q5, and is composed of, for example, a field effect transistor. In this embodiment, a so-called four-stone full bridge type polarity inverting circuit having switching elements Q2 to Q5 is adopted as the polarity inverting circuit. Since the operation of this full-bridge type polarity reversing circuit is well known, the explanation of the operation is omitted. Although not shown, for example, an integrated circuit M63991FP manufactured by Mitsubishi Electric Corporation may be used to drive the switching elements Q2 to Q5. The load circuit is composed of an inductor L2 and a capacitor C6 connected in series. The high pressure discharge lamp LA is, for example, an HID lamp such as a high pressure sodium lamp, a metal halide lamp, and a mercury lamp. The igniter circuit has a peak value of several kV and a width of several tens to several hundreds of μs when the high pressure discharge lamp is started.
A pulse voltage of about ec is generated, and this pulse voltage is applied to both ends of the high pressure discharge lamp LA. here,
The switching element SW that constitutes the igniter circuit is a bidirectional two-terminal element having a predetermined breakdown threshold, and is, for example, a thyristor or a triac. The pulse transformer PT has a primary winding and a secondary winding, and boosts the voltage generated in the primary winding to the secondary winding according to the winding number ratio. According to the present embodiment, the partition plate 5 separates the space inside the case, and in the state where the high-pressure discharge lamp LA is lit, the electronic component 1b having a high temperature is arranged in the divided space 7b. ing. Therefore, it suffices to fill only the space 7b with the resin, and it is possible to radiate heat from the heat-generating component with the minimum necessary filling amount.
Therefore, the amount of resin used can be reduced, the weight of the entire discharge lamp lighting device can be reduced, and the cost and size of the discharge lamp lighting device can be reduced. In addition, a partition plate 5 is provided to divide the space inside the case.
Since it is a simple one that is simply installed upright on the case body 3, the manufacturing process of the discharge lamp lighting device can be simplified. Further, when the electronic component having a high temperature is a chip component, as an application of the present embodiment, the partition plate 5 is erected on the bottom surface of the case body 3 as shown in FIG. The printed circuit board 2 may be disposed in the. In addition,
The operations, effects, and the like not specifically mentioned in the above description are the same as those in the above embodiment. Next, a second embodiment of the present invention will be described with reference to FIG. In FIG. 4, two partition plates 5 that partition the space inside the case are provided, and the spaces divided by the partition plates 5 are 7a, 7b, and 7c, respectively. Depending on the circuit configuration of the discharge lamp lighting device, it may include an electronic component 1c that cannot be filled with resin, such as a terminal block, an aluminum electric field capacitor, or a glass tube fuse. Even in the case of such a discharge lamp lighting device, a space for the electronic component 1c, which cannot be filled with resin by the partition plate 5, is separately provided so as not to be covered with the filling material, and a space where the electronic component 1b having a high temperature is arranged. 7b may be filled with resin. The operations, effects, and the like not specifically mentioned in the above description are the same as those in the first embodiment. Next, a third embodiment of the present invention will be described with reference to FIGS. In consideration of the case where the discharge lamp lighting device is arranged in the lighting fixture and attached to the ceiling surface or the like, the partition plate 5 may be provided upright on the bottom surface of the case lid 4 as shown in FIG. Further, when the case body 3 is made of metal and the case lid 4 is made of plastic, the heat radiation of the high temperature electronic component 1b may be insufficient with only the filler shown in FIG. In such a case, as shown in FIG. 6, a metal heat dissipation plate 8 may be separately provided along the side surface and the bottom surface of the case body 3. By doing so, heat conduction occurs from the filling material 6 to the case main body 3 via the heat dissipation plate 8, and the heat of the electronic component 1b, which becomes hot, can be effectively dissipated. The operation not particularly mentioned in the above description,
The effects and the like are similar to those of the first embodiment.

In the electronic component mounting structure according to any one of claims 1 to 3, at least one of the case main body and the case lid is provided with a partition plate for partitioning the space inside the case, and is partitioned. Spaces are in communication with each other, electronic parts that require heat dissipation are arranged in the space, and the space is filled with resin, so the space inside the case is completely partitioned and the entire space is filled with resin. It is not necessary to do so, and the heat-generating component can be radiated while reducing the filling amount of the resin. Since the filling amount of the resin can be reduced, the weight of the entire discharge lamp lighting device can be reduced and the cost can be reduced. Further, since each space is separated by a simple configuration in which at least one of the case body and the case lid is provided with a partition plate for partitioning the space inside the case, the manufacturing process can be simplified.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing a first embodiment.

FIG. 2 is a circuit diagram showing a first embodiment.

FIG. 3 is a cross-sectional view showing an application form of the first embodiment.

FIG. 4 is a cross-sectional view showing a second embodiment.

FIG. 5 is a cross-sectional view showing a third embodiment.

FIG. 6 is a sectional view showing an application form of a third embodiment.

FIG. 7 is a cross-sectional view showing a conventional example.

[Explanation of symbols]

1a, 1b, 1c Electronic parts 2 printed circuit boards 3 Case body 4 case lid 5 partition boards 6 resin 7a, 7b, 7c space 8 heat sink

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Kenichi Fukuda             1048, Kadoma, Kadoma-shi, Osaka Matsushita Electric Works Co., Ltd.             Inside the company F-term (reference) 4E360 BA08 ED22 EE08 GA24                 5E322 AA03 CA05 FA04

Claims (3)

[Claims] 1. An electronic component mounting structure having a printed circuit board on which electronic components are mounted on both sides, a case main body accommodating the printed circuit board, and a case lid that covers the case main body, at least the case main body or the case cover. A partition plate for partitioning the space inside the case is provided on either side, and the partitioned spaces are in communication with each other. An electronic component mounting structure, characterized in that the resin is filled with resin. 2. The electronic component mounting structure according to claim 1, wherein at least one electronic component that cannot be filled is included. 3. The electronic component mounting structure according to claim 1, wherein the electronic component having a heat sink is filled together with the heat sink.