JP2010073942A - Electronic circuit device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electronic circuit device that can cope with an increase in heat generation density by appropriately conducting heat to the side of a main circuit board and capable of radiating heat efficiently and reliably for heat generation of an electronic circuit chip. <P>SOLUTION: The electronic circuit chip 1 made of a semiconductor element, such as an integrated circuit, is mounted on a base substrate 2, and the base substrate 2 is covered with a case member 3 for fitting for composing as a module operating as a prescribed functional element. A heat-conducting member 4 is provided between the electronic circuit chip 1 and the case member 3, and the case member 3 is set to be a radiator. When connection of the case member 3 is adjusted and the base substrate 2 is mounted on a main circuit board 5, the peripheral edge is allowed to abut on a conductor pattern 6 on the surface of the main circuit board 5, thus connecting thermal conductivity to the side of the main circuit board 5. Then, a connection member connects thermal conductivity by providing a solder fillet 7 at the periphery edge of the case member 3. A thermally conductive path can be formed for both the front and rear sides of the electronic circuit chip 1, thus conducing generated heat to the main circuit board 5 by any one of paths. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an electronic circuit device in which a module of an electronic circuit chip is mounted on a main circuit board. More specifically, the present invention relates to an improvement in heat dissipation that guides heat generated by the electronic circuit chip to the outside and dissipates heat.

  As is well known, an electronic circuit chip made of a semiconductor element or the like is modularized. That is, an electronic circuit chip made of a semiconductor element such as a so-called integrated circuit is mounted on a base substrate and covered with a case member to constitute a module that functions as a predetermined functional element. Such modules are used by being mounted on the main circuit board.

  Electronic circuit chips generate heat. Increasing the heat generation density has become a problem with the recent progress in miniaturization and density. Therefore, as a countermeasure for dissipating the heat generated by the electronic circuit chip, there is a proposal of a technique as seen in Patent Documents 1 and 2, for example.

  Patent Document 1 discloses a proposal of a configuration in which a heat conducting member is provided. Specifically, a heat conductive member is provided in an arrangement in contact with the conductor layer on the substrate on which the electronic circuit chip is mounted and the case covering them, and the heat generation of the electronic circuit chip is guided to the substrate side and is transmitted from the conductor layer. The heat conduction member conducts the heat, and the heat conduction member leads to the case side to dissipate heat.

Patent Document 2 discloses a proposal of a configuration in which a heat conductive member using a leaf spring is provided. Specifically, the electronic circuit chip is mounted on the substrate in a flip-chip manner, and a leaf spring is disposed between the cover member covering these and the back surface of the electronic circuit chip. As a result, the heat generated by the electronic circuit chip is guided to the lid member side by the leaf spring and is radiated. And the heat dissipation fin is provided in the cover material.
JP 2003-115564 A JP-A-5-13627

  However, such conventional heat dissipation measures have the following problems. In the invention disclosed in Patent Document 1, the heat generation of the electronic circuit chip is first led to the substrate side, and is conducted from the conductor layer to the heat conducting member and led to the case side, so that the thermal resistance on the substrate side is large and the heat radiation is efficient. There is a problem that cannot be done well.

  In the invention disclosed in Patent Document 2, the heat generated by the electronic circuit chip is guided by the leaf spring to the lid material side to dissipate heat. Therefore, the efficiency of heat radiation depends on the thermal resistance on the lid material side, and the heat dissipation provided in the lid material. Although the thermal resistance is reduced by the fins, it is insufficient from the viewpoint of increasing the heat generation density due to the recent miniaturization and densification.

  The object of the present invention is to solve the above-mentioned problems. The purpose of the present invention is to efficiently conduct heat to the main circuit board side with respect to the heat generation of the electronic circuit chip, and to cope with an increase in the heat generation density, thereby efficiently and reliably radiating heat. It is an object of the present invention to provide an electronic circuit device that can be performed in the same manner.

  In order to achieve the above-described object, an electronic circuit device according to the present invention includes (1) an electronic circuit chip made of a semiconductor element, a base substrate on which the electronic circuit chip is mounted, and a heat conductive and covering base substrate. A case member to be mounted, a heat conduction member provided between the flexible electronic circuit chip and the case member, and a base substrate mounted on the main circuit substrate, between the case member and the main circuit substrate. And a heat conduction means for linking heat conduction.

  Further, (2) the heat conducting member can be made of a paste material or a gel material having heat conductivity, and (3) it may be made of an elastic material such as a leaf spring or a coil spring. (4) The leaf spring can be formed by forming a cut in a corresponding part of the case member and bending it.

  Further, (5) the heat conduction means links the heat conduction between the two parts by a configuration in which the corresponding part of the case member is brought into contact with the main circuit board. Alternatively, (6) a heat conductive linkage member can be provided between the case member and the main circuit board by providing a heat conductive linkage member, and (7) the linkage member is made of a solder material. May be.

  With this configuration, in the present invention, since the heat conductive member is provided between the electronic circuit chip and the case member, the heat generated by the electronic circuit chip is conducted from the heat conductive member to the case member, and the case member radiates heat. And since the heat conduction means links the heat conduction between the case member and the main circuit board, the heat conduction is conducted from the case member side to the main circuit board side, and the heat conduction path on the surface side of the electronic circuit chip. Can be formed. On the mounting surface side of the electronic circuit chip, there is a heat conduction path through the base substrate, and heat generation is conducted from the base substrate to the main circuit substrate.

  Therefore, a heat conduction path can be formed on both the front and back surfaces of the electronic circuit chip, and heat can be conducted to the main circuit board in any path. In this way, it is possible to form a path that conducts from the electronic circuit chip to the main circuit board without going through the base board. It is possible to realize good heat dissipation even when the heat dissipation of the electronic circuit chip is impaired due to the thermal resistance to conduct from the chip to the base substrate and the heat conduction inside the base substrate. it can. And since the main circuit board has a large surface area and a large heat capacity, a heat radiation effect can be expected.

  In the electronic circuit device according to the present invention, the heat conduction member is provided between the electronic circuit chip and the case member, and the heat conduction means links the heat conduction between the case member and the main circuit board. A heat conduction path can be formed on the surface side of the substrate. On the mounting surface side of the electronic circuit chip, there is a heat conduction path through the base substrate. Therefore, a heat conduction path can be formed on both the front and back surfaces of the electronic circuit chip, and heat is transmitted to the main circuit board in either path. In addition, since the main circuit board has a large surface area and a large heat capacity, a heat radiation effect can be expected.

  For this reason, the heat generation of the electronic circuit chip can be favorably conducted to the main circuit board side, the heat density can be increased, and the heat can be efficiently and reliably radiated.

  FIG. 1 shows a first embodiment of the present invention. In this embodiment, the electronic circuit device is configured such that the module of the electronic circuit chip 1 is mounted on the main circuit board 5, and the heat generated by the electronic circuit chip 1 is guided to the outside and radiated.

  The electronic circuit chip 1 is made of a semiconductor element such as a so-called integrated circuit and is mounted on the base substrate 2. A case member 3 is mounted on the base substrate 2 so as to cover the electronic circuit chip 1 and is configured as a module that functions as a predetermined functional element. In this module, the heat conductive member 4 is provided between the electronic circuit chip 1 and the case member 3 and the base substrate 2 is mounted on the main circuit substrate 5. It is the structure which performs the cooperation of heat conduction between.

Conductive patterns 6 are appropriately formed on the surface of the base substrate 2 and the main circuit substrate 5. The conductor pattern 6 forms a wiring pattern for connecting elements to each other in order to obtain a predetermined circuit function, but a pattern portion for conducting heat conduction for heat radiation is also appropriately formed.
The case member 3 is formed of a metal material having high thermal conductivity such as copper, but may be made of a metal material such as stainless steel.

  The heat conducting member 4 is preferably formed from a flexible material. This is to prevent stress concentration on the electronic circuit chip 1, and the heat conducting member 4 is formed of, for example, a paste material or a gel material having heat conductivity. In the case where the stress concentration can be ignored, a metal material having a high thermal conductivity such as copper can be used for the heat conducting member 4. Of course, since the heat conduction member 4 obtains good heat conduction, it is preferable to set the contact area between the electronic circuit chip 1 and the case member 3 as large as possible.

  The heat conduction member 4 having flexibility is set so that a predetermined pressure is applied, and a slight repulsive force acts between the electronic circuit chip 1 and the case member 3. Thereby, a good contact state can be maintained with respect to the electronic circuit chip 1 and the case member 3.

  The case member 3 is mounted by adjusting the depth of covering of the base substrate 2, and when the base substrate 2 is mounted on the main circuit substrate 5, the peripheral edge thereof is a conductor on the surface of the main circuit substrate 5. It is set to come into contact with the pattern 6. That is, in mounting the base substrate 2 on the main circuit board 5, the peripheral edge of the case member 3 comes into contact with the conductor pattern 6 on the surface of the main circuit board 5, and between the case member 3 and the main circuit board 5. It is configured to link heat conduction.

  In mounting the base substrate 2 on the main circuit substrate 5, a solder fillet 7 is provided at the peripheral edge of the case member 3. Since this solder fillet 7 also has thermal conductivity, it becomes a linkage member (thermal conduction means) that links thermal conduction between the case member 3 and the main circuit board 5 and can conduct heat conduction well as will be described later. become.

  As described above, the heat conducting member 4 is provided between the electronic circuit chip 1 and the case member 3, and the case member 3 is in contact with the main circuit board 5 at the peripheral edge, and further, at the peripheral edge of the case member 3, Since the solder fillet 7 is provided, a heat conduction path can be formed on the surface side of the electronic circuit chip 1. The heat generated in the electronic circuit chip 1 is conducted from the heat conducting member 4 to the case member 3 to dissipate heat, and the heat conduction is conducted to the main circuit board 5 side. On the mounting surface side of the electronic circuit chip 1, there is a heat conduction path through the base substrate 2, and heat generation is conducted from the base substrate 2 to the main circuit substrate 5.

  In this way, a path that conducts from the electronic circuit chip 1 to the main circuit board without passing through the base board 2 can be formed. The electronic circuit chip 1 is electrically connected to the base substrate 2 mainly using solder, and the contact area is often limited. Further, the base substrate 2 may not be able to maintain satisfactory thermal conductivity for reasons of electrical characteristics, substrate area, cost, or the like. Under such circumstances, the heat resistance for conducting from the chip to the base substrate and the heat conduction inside the base substrate impair the overall heat dissipation, and no matter how much the heat dissipation of the main circuit board is improved, the heat dissipation of the chip It is not possible to increase sex. Therefore, a heat conduction path can be formed on both the front and back surfaces of the electronic circuit chip 1, heat can be transmitted to the main circuit board 5 in any path, and the main circuit board 5 has a large surface area and a large heat capacity. Due to synergy with the heat dissipation in the case member 3, the heat dissipation of the electronic circuit chip 1 can be efficiently and reliably performed. As a result, it is possible to cope with an increase in heat generation density of the electronic circuit chip 1.

  The heat conduction member 4 having flexibility is set to apply a predetermined pressure. As a result, a slight repulsive force can be applied between the electronic circuit chip 1 and the case member 3, and a good contact state between the electronic circuit chip 1 and the case member 3 can be maintained. . For this reason, manufacturing intersections and dimensional variations can be absorbed by the heat conducting member 4, and a certain amount of deformation error can be allowed, and the heat conducting member 4 is in contact with the electronic circuit chip 1 and the case member 3. Is maintained well, so that heat radiation performance can be obtained with high reliability.

(Verification by numerical analysis)
The configuration shown in FIG. 1 was modeled and numerical analysis was performed to evaluate heat conduction. As a result, when the electronic circuit chip 1 generates heat of 0.6 W in an environment with a temperature of 300 [K], the maximum temperature is 313.41 [K] in the configuration in which the heat conducting member 4 is not provided. On the other hand, it was confirmed that there is a temperature drop of the difference temperature ΔT = 0.93 [K] in the configuration in which the heat conducting member 4 is provided.

  The electronic circuit chip 1 is not limited to a semiconductor element, and may be any chip body that forms an electronic circuit. For example, as shown in FIG. 2, a configuration using a chip component 8 for so-called surface mounting can be adopted. The chip component 8 includes functional elements such as an inductor (L: induction element), a capacitor (C: capacitance element), a resistance element, or a filter element configured by incorporating a plurality of LCs. Since the chip component 8 is generally provided with electrodes at both ends, the heat conducting member 4 is preferably formed of an insulating material in order to prevent a short circuit. And as for arrangement | positioning of the heat conductive member 4, the arrangement | positioning which contacts the center site | part etc. which avoided the electrode site | part is preferable.

  The case member 3 may be configured to be uneven so as to increase the surface area and improve the heat dissipation performance. For example, as shown in FIG. 3, a portion that contacts the heat conducting member 4 is formed in a protruding shape toward the base substrate 2 to form a recess 30, and the thickness of the heat conducting member 4 is reduced, and the surface area of the case member 3 is reduced. It is also possible to adopt a configuration that increases Of course, a material having high thermal conductivity is used for the heat conducting member 4. However, since the thickness of the member is thin, the heat resistance is reduced, which is advantageous for heat conduction. Improvement can be expected.

  FIG. 4 shows a second embodiment of the present invention. In this embodiment, the electronic circuit device is basically the same as that of the first embodiment, and the module of the electronic circuit chip 1 is mounted on the main circuit board 5, and the heat generation of the electronic circuit chip 1 is transmitted to the outside. It is configured to guide and dissipate heat. The same components as those in the first embodiment are denoted by the same reference numerals, and the description thereof is omitted.

  In this embodiment, a plate spring 31 is used as the heat conducting member, and the case member 3 has a reduced peripheral height to change the relationship with the base substrate 2. Here, the case member 3 is set so that the peripheral edge reaches the surface of the base substrate 2 and contacts the conductor pattern 6 on the base substrate 2. For this reason, a solder fillet 7 is provided as a means for linking heat conduction, and is formed so as to be greatly grown from the peripheral edge of the case member 3 to the conductor pattern 6 on the main circuit board 5.

  The leaf spring 31 is formed by providing a cut at a corresponding portion of the case member 3 and bending it. In this case, the heat conducting member 4 is provided between the electronic circuit chip 1 and the case member 3, and the case member 3 does not contact the peripheral edge of the main circuit board 5. Since the fillet 7 is provided large, a heat conduction path can be formed on the surface side of the electronic circuit chip 1, and heat generation is conducted from the heat conduction member 4 to the case member 3 and then to the main circuit board 5. . Note that even in a configuration in which the case member 3 is not directly connected to the main circuit board 5 but is connected in the vicinity of the peripheral edge of the base board 2, a thermal resistance for transferring heat from the electronic circuit chip 1 to the base board 2. Therefore, it is possible to set a path in which most of the process of heat moving inside the base substrate 2 is omitted, so that sufficient heat dissipation can be improved.

  Accordingly, heat conduction paths can be formed on both the front and back surfaces of the electronic circuit chip 1, heat can be transmitted to the main circuit board 5 in both the front and back paths of the electronic circuit chip 1, and the main circuit board 5 has a large surface area and a large heat capacity. A heat dissipating action can be expected, and heat dissipation of the electronic circuit chip 1 can be efficiently and surely performed by synergy with heat dissipation in the case member 3. As a result, it is possible to cope with an increase in heat generation density of the electronic circuit chip 1.

  The leaf spring 31 is an integral part composed of the corresponding part of the case member 3, but the heat conducting member is not limited to such an integral structure. For example, as shown in FIG. 5, an independent plate spring 9 made of a separate member may be provided between the electronic circuit chip 1 and the case member 3 and used as a heat conducting member. Moreover, as shown in FIG. 6, the structure which uses the coil spring 10 as a heat conductive member is good.

  FIG. 7 shows a third embodiment of the present invention. In this embodiment, the electronic circuit device is basically the same as in the first and second embodiments, and the module of the electronic circuit chip 1 is mounted on the main circuit board 5, and the heat generation of the electronic circuit chip 1 is performed. It is configured to guide heat to the outside and dissipate heat. The same components as those in the first and second embodiments are denoted by the same reference numerals, and the description thereof is omitted.

  In this embodiment, the heat conducting member 4 is disposed on the side surface of the electronic circuit chip 1. The main circuit board 5 is provided with a large number of heat dissipating fins 11 to increase the surface area for heat dissipation and reduce the thermal resistance.

  In this case, since a large number of heat radiation fins 11 are provided on the main circuit board 5, heat radiation can be performed with higher efficiency, and heat generation of the electronic circuit chip 1 can be performed with high efficiency, further improving the heat radiation performance. it can.

1 is a cross-sectional view showing a first embodiment of an electronic circuit device according to the present invention. It is sectional drawing of the principal part explaining the other example of an electronic circuit chip. It is sectional drawing of the principal part explaining the other example of a case member. It is sectional drawing which shows 2nd Embodiment of the electronic circuit apparatus which concerns on this invention. It is sectional drawing of the principal part explaining the other example 1 of a heat conductive member. It is sectional drawing of the principal part explaining the other example 2 of a heat conductive member. It is sectional drawing which shows 3rd Embodiment of the electronic circuit apparatus which concerns on this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Electronic circuit chip 2 Base board 3 Case member 4 Thermal conduction member 5 Main circuit board 6 Conductor pattern 7 Solder fillet (linking member)
8 Chip component 9 Leaf spring 10 Coil spring 11 Radiation fin 30 Recess 31 Leaf spring

Claims (7)

An electronic circuit chip made of a semiconductor element or the like;
A base substrate on which the electronic circuit chip is mounted;
A case member that is thermally conductive and covers and attaches to the base substrate;
A heat conducting member that is flexible and is provided between the electronic circuit chip and the case member;
An electronic circuit device comprising: heat conduction means for linking heat conduction between the case member and the main circuit board when the base board is mounted on the main circuit board.   2. The electronic circuit device according to claim 1, wherein the heat conducting member is made of a paste material or a gel material having heat conductivity.   The electronic circuit device according to claim 1, wherein the heat conducting member is made of an elastic material such as a leaf spring or a coil spring.   4. The electronic circuit device according to claim 3, wherein the leaf spring is formed by forming a cut at a corresponding portion of the case member and bending the same. 5.   2. The electronic circuit device according to claim 1, wherein the heat conducting means performs a heat conduction linkage between the two by a configuration in which a corresponding portion of the case member is brought into contact with the main circuit board.   2. The electron according to claim 1, wherein the heat conducting means performs heat conduction linkage between the case member and the main circuit board by providing a heat conductive linking member between the case member and the main circuit board. Circuit device.   The electronic circuit device according to claim 6, wherein the linking member is made of a solder material.

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