JP2015012161A - Electronic device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a heat radiation structure capable of radiating heat without requiring a heat radiation element such as a Peltier element, while securing insulation between a heating member such as a heater element and the outside.SOLUTION: A conductor layer 14 is disposed at a lower side of an electronic component 20 that becomes a heater element, and the conductor layer 14 extends in a plane direction of a substrate 10. A heat radiation member 40 is disposed at a position opposing the conductor layer 14 with an insulation material portion of the substrate 10 interposed therebetween. In such a configuration, heat generated in the electronic component 20 is transferred to the conductor layer 14, conducted in the plane direction of the substrate 10 via the conductor layer 14, transferred to the heat radiation member 40 and discharged from a top face of the heat radiation member 40 exposed from a mold resin 50 to the outside. Thus, heat radiation is satisfactorily performed even without requiring a heat radiation element such as a Peltier element. Further, since the insulation material portion of the substrate 10 is present between the conductor layer 14 and the heat radiation member 40, the electronic component 20 can be surely insulated from the outside by the insulation material portion.

Description

  The present invention relates to an electronic device in which a heat generating member such as a heat generating element is disposed on one side of a substrate.

  Conventionally, Patent Document 1 discloses a heat dissipation structure in a mold package in which a heat generating element is disposed on one side of a substrate and the heat generating element is sealed with a mold resin. In this heat dissipation structure, a Peltier element or the like serving as a heat dissipation element is disposed on the surface layer portion of the interposer disposed below the heat generation element, and is exposed from the mold resin to the side of the heat generation element while being in contact with the heat dissipation element. It is comprised by arrange | positioning a heat-transfer part. In such a configuration, the heat generated by the heat generating element is transmitted to the heat transfer section via the heat radiating element, and is released to the outside of the mold resin.

JP 2008-153393 A

  However, the heat dissipating structure described in Patent Document 1 requires a heat dissipating element such as a Peltier element, the heat generating element is directly connected to the heat transfer part via the heat dissipating element, and the heat transfer part is Since the structure is exposed from the mold resin, insulation between the heating element and the outside cannot be ensured.

  In view of the above, the present invention does not require a heat-dissipating element such as a Peltier element, and has an heat-dissipating structure that can dissipate heat while ensuring insulation between a heat-generating member such as a heat-generating element and the outside. The purpose is to provide.

  In order to achieve the above object, in the invention described in claim 1, the heat generating member (20) is disposed on the one surface (11) side of the substrate (10) on which the first conductor layer (13) is formed, and the heat generating member is disposed. In the electronic component sealed with the mold resin (50), a via (15) formed from one surface of the substrate to the inside of the substrate at a position where the heat generating member is disposed on one surface of the substrate, and the interior of the substrate And a second conductor layer (14) extending in a plane direction of the substrate from a position facing the heat generating member and connected to the via, and an insulation provided on one side of the substrate and serving as a base of the substrate The second conductor layer is disposed so as to face the portion extending in the horizontal direction of the substrate from the position facing the heating member in the second conductor layer, and is extended toward the upper surface (50b) of the mold resin. Consists of materials with higher thermal conductivity than mold resin It is characterized in that comprises a, and the heat radiating member (40) which.

  According to such a configuration, heat generated by the heat generating member is transmitted to the second conductor layer disposed below the heat generating member, for example, the electronic component (20) serving as the heat generating element. For this reason, heat is transferred in the plane direction of the substrate through the second conductor layer, this is transferred to the heat radiating member, and is released to the outside from the upper surface side of the mold resin through the heat radiating member. At this time, since there is an insulating material portion of the substrate between the heat radiating member and the second conductor layer, heat transfer may be hindered by this insulating material portion, but the thickness of the substrate itself is small, and the heat radiating member and the second conductor layer Of course, the thickness of the insulating material portion interposed between the conductor layers is also thin. For this reason, even if there is an insulating material portion of the substrate between the heat radiating member and the second conductor layer, heat transfer from the second conductor layer to the heat radiating member is performed without much inhibition of heat transfer. You can In particular, if the insulating material portion interposed between the heat dissipation member and the conductor layer is set to have a high thermal conductivity, heat transfer from the second conductor layer to the heat dissipation member can be performed more favorably.

  Since the insulating material portion is interposed between the heat dissipation member and the second conductor layer, it is possible to ensure insulation between the heat generating member or the second conductor layer and the heat dissipation member. Therefore, it is possible to provide an electronic device having a heat dissipation structure that does not require a heat dissipation element such as a Peltier element and that can perform heat dissipation while ensuring insulation between the heat generating member and the outside.

  In addition, the code | symbol in the bracket | parenthesis of each said means shows an example of a corresponding relationship with the specific means as described in embodiment mentioned later.

It is sectional drawing of the mold package with which the electronic device concerning 1st Embodiment of this invention is equipped. It is sectional drawing of the mold package with which the electronic device concerning 2nd Embodiment of this invention is equipped. It is sectional drawing of the mold package with which the electronic apparatus concerning 3rd Embodiment of this invention is equipped. It is sectional drawing of the mold package with which the electronic device concerning 4th Embodiment of this invention is equipped.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following embodiments, parts that are the same or equivalent to each other will be described with the same reference numerals.

(First embodiment)
An electronic device according to a first embodiment of the present invention will be described. Here, a mold package provided in the electronic device will be described with reference to FIGS. An electronic device provided with this mold package is mounted on a vehicle such as an automobile, and is applied as a device for driving various electronic devices for vehicles.

  As shown in FIG. 1, the electronic device of this embodiment includes a substrate 10, electronic components 20 and 30, a heat dissipation member 40, a mold resin 50, and the like, and the electronic components 20 and 30 and the heat dissipation member 40 mounted on the substrate 10. The resin is sealed with a mold resin 50.

  The substrate 10 forms a plate-like member having one surface 11 on which the electronic components 20 and 30 and the heat radiating member 40 are mounted and covered with the mold resin 50 and the other surface 12 which is the opposite surface. The upper surface shape is a rectangular plate-shaped member.

  Specifically, the substrate 10 is formed of a multilayer substrate such as a printed circuit board in which an insulating material portion serving as a base is made of a resin such as an epoxy resin. The substrate 10 includes a conductor layer 13 constituting a land, a wiring pattern and the like on one surface 11 side, and a conductor layer 14 constituting an inner layer wire and the like between the one surface 11 and the other surface 12, that is, inside the substrate 10. I have.

  The conductor layer 13 corresponds to the first conductor layer, and constitutes a land for connecting to the electronic components 20 and 30 and the heat dissipating member 40, a wiring pattern connected to the land, and the like, for example, composed of a metal such as Cu. Has been. The electronic components 20 and 30 are electrically connected to the wiring pattern formed on the substrate 10 by being electrically and mechanically joined to the conductor layer 13.

  The conductor layer 14 corresponds to the second conductor layer, and is used to configure a wiring pattern that is electrically connected to the conductor layer 13 or to configure a heat dissipation path. For example, a multilayer board is constructed by laminating build-up layers on both sides centered on a core layer made of resin or the like, and inner layer wiring is arranged between these core layers and build-up layers. The conductor layer 14 can be constituted by this inner layer wiring.

  In the case of the present embodiment, the conductor layer 14 extends in a lateral direction (a planar direction of the substrate 10) from a position facing the electronic component 20 at a position below the electronic component 20, and extends below the heat radiating member 40. ing. A via 15 is formed in the substrate 10 between the conductor layer 13 and the conductor layer 14 disposed below the electronic component 20, so that the conductor layer 13 and the conductor layer 14 are thermally and electrically connected. It is connected. The via 15 is formed by disposing a conductive material 15 b in a recess 15 a formed from the one surface 11 side of the substrate 10 toward the inside of the substrate 10. The recess 15a is a laser via hole formed by a laser, for example, and is formed so as to reach the conductor layer 14 from the one surface 10 side.

  The electronic components 20 and 30 are electrically connected to the wiring pattern by being mounted on the substrate 10, and may be any surface mounting component or through-hole mounting component. In the case of the present embodiment, the heating elements 20 and the passive elements 30 will be described as examples of the electronic components 20 and 30. The heat generating element 20 corresponds to a heat generating member of the present invention, and a power element that generates particularly large heat such as an IGBT (Insulated Gate Bipolar Transistor) or a MOSFET (Metal-Oxide-Semiconductor Field-Effect Transistor) is assumed. However, a microcomputer or a control element may be used. The heating element 20 is connected to the conductor layer 13 by a bonding wire 21 and a die bonding material 22 such as solder. Examples of the passive element 30 include a chip resistor, a chip capacitor, and a crystal resonator. The passive element 30 is connected to the conductor layer 13 by a die bond material 31 such as solder. With these configurations, the electronic components 20 and 30 are electrically connected to the conductor layer 13 formed on the substrate 10, that is, the wiring pattern, and are electrically connected to the outside through a through hole (not shown) connected to the wiring pattern. It is possible.

  The heat dissipating member 40 is a member constituting a heat dissipating path for dissipating heat generated by the electronic component 20, and is made of a heat dissipating material higher than the mold resin 50, such as Cu, Cu alloy, Al or the like. . The heat dissipating material 40 is disposed on one surface 11 side of the substrate 10 so as to face a portion of the conductor layer 14 that extends in the plane direction of the substrate 10 from below the electronic component 20 with the insulating material portion of the substrate 10 interposed therebetween. Has been. The heat radiating member 40 is sealed in the mold resin 50 together with the electronic components 20, 30 and the like. However, in this embodiment, the upper surface of the heat radiating member 40 is exposed from the mold resin 50. The heat radiating member 40 is also connected to the conductor layer 13 formed on the one surface 11 of the substrate 10 by a die bonding material 41 such as solder. A portion of the conductor layer 13 to which the heat dissipation member 40 is connected is a floating land that is electrically separated from other portions of the conductor layer 13 (for example, portions connected to the electronic components 20 and 30). Yes. As described above, the conductor layer 14 extends to a position below the heat radiating member 40, but the insulating material portion of the substrate 10 is between the conductor layer 13 and the conductor layer 14 connected to the heat radiating member 40. The insulation is ensured between them.

  In addition, although the insulating material part used as the base of the board | substrate 10 is fundamentally comprised with resin, such as an epoxy resin, it is comprised with an insulating material with higher heat conductivity, or thermal conductivity is filled by filler filling. It can also be raised. In particular, since it is preferable that the portion of the substrate 10 located between the heat dissipation member 40 and the conductor layer 14 has high thermal conductivity, only this portion may have high thermal conductivity. good.

  The mold resin 50 is made of a thermosetting resin such as an epoxy resin, and is formed by a transfer molding method using a mold or a compression molding method. In the case of the present embodiment, a so-called half mold structure is formed in which the one surface 11 side of the substrate 10 is sealed with the mold resin 50 and the other surface 12 side of the substrate 10 is exposed without being sealed with the mold resin 50. . The mold resin 50 has a plate shape having a lower surface 50a that is a surface in contact with the one surface 11 of the substrate 10, an upper surface 50b opposite to the lower surface, and a side surface 50c that connects the upper and lower surfaces 50a and 50b. The surface of the heat radiating member 40 is exposed from the upper surface 50b. In the present embodiment, the exposed surface of the heat radiating member 40 and the upper surface 50b are configured to be in the same plane. Typically, the mold resin 50 is configured to have a rectangular top surface shape, but may be another polygonal shape or the like.

  With the above structure, a mold package provided in the electronic device according to the present embodiment is configured.

  In the electronic device having such a configuration, the conductor layer 14 is disposed below the electronic component 20 serving as a heating element, and heat generated by the electronic component 20 is transmitted to the conductor layer 14. Then, heat is transferred in the plane direction of the substrate 10 through the conductor layer 14, and is transmitted to the heat radiating member 40 and is discharged to the outside from the upper surface of the heat radiating member 40 exposed from the mold resin 50. At this time, since there is an insulating material portion of the substrate 10 between the heat radiating member 40 and the conductor layer 14, heat transfer can be hindered by this insulating material portion, but the thickness of the substrate 10 itself is thin and the heat radiating member 40. Of course, the thickness of the insulating material portion interposed between the conductor layer 14 and the conductor layer 14 is also thin. For this reason, even if there is an insulating material portion of the substrate 10 between the heat dissipation member 40 and the conductor layer 14, heat transfer from the conductor layer 14 to the heat dissipation member 40 is performed without hindering heat transfer. Can be In particular, if the insulating material portion interposed between the heat radiating member 40 and the conductor layer 14 has a high thermal conductivity, heat transfer from the conductor layer 14 to the heat radiating member 40 can be performed more favorably. For example, when the substrate 10 has a core layer and a build-up layer disposed on both sides of the core layer, the build-up layer may be made of a material having a higher thermal conductivity than the core layer.

  Since the insulating material portion is interposed between the heat dissipation member 40 and the conductor layer 14 as described above, it is possible to ensure insulation between the electronic component 20 or the conductor layer 14 and the heat dissipation member 40. . Therefore, it is possible to provide an electronic device having a heat dissipation structure that does not require a heat dissipation element such as a Peltier element and that can perform heat dissipation while ensuring insulation between the electronic component 20 serving as a heat generating element and the outside.

(Second Embodiment)
A second embodiment of the present invention will be described. In this embodiment, the relationship between the heat dissipation member 40 and the mold resin 50 is changed with respect to the first embodiment, and the other parts are the same as those in the first embodiment. Only explained.

  As shown in FIG. 2, in the present embodiment, the upper surface of the heat radiating member 40 is not exposed from the upper surface 50 a of the mold resin 50, and is covered with the mold resin 50. That is, the height of the upper surface 50 b of the mold resin 50 from the one surface 11 of the substrate 10 is higher than that of the heat dissipation member 40. However, the thickness of the mold resin 50 covering the upper surface of the heat radiating member 40 is thin, for example, 0.5 mm or less.

  Thus, even if the upper surface of the heat radiating member 40 is covered with the mold resin 50, heat can be radiated through the thin mold resin 50, so that the same effect as in the first embodiment can be obtained. If the mold resin 50 covering the upper surface of the heat radiating member 40 is thick, heat radiation cannot be performed sufficiently.

  Here, as described above, the mold resin 50 is molded by a transfer molding method or a compression molding method. To expose the upper surface of the heat dissipation member 40 from the mold resin 50 during molding, the inner wall surface of the molding die is used. It is necessary to contact the upper surface of the heat radiating member 40. However, it is difficult to reliably bring the inner wall surface of the mold into contact with the upper surface of the heat dissipation member 40.

  In particular, it is difficult to mold the mold resin 50 by the compression molding method. That is, in the compression molding method, the lower mold is brought into contact with the lower surface 12 side of the substrate 10, and the upper mold having the opening that constitutes the cavity is brought into contact with the upper surface 11, thereby opening the upper mold. Molding is performed by sliding the plunger in a state where the resin powder is filled in the portion. At this time, the height of the upper surface 50b of the mold resin 50 is determined by the amount of insertion of the plunger. However, it is difficult to reliably match the height of the upper surface 50b with the upper surface of the heat dissipation member 40. If it presses to the board | substrate 10 side, it may damage the board | substrate 10. On the other hand, when the height of the upper surface 50b of the mold resin 50 is higher than the upper surface of the heat radiating member 40 from the one surface 11 as in the present embodiment, the plunger urges the heat radiating member 40. Can be prevented. For this reason, in particular, when the mold resin 50 is molded by the compression molding method, the heat radiation member 40 is pressed by the plunger and pressed against the substrate 10 by using a structure in which the mold resin 50 is left thin as in the present embodiment. Damage can be prevented from being added.

(Third embodiment)
A third embodiment of the present invention will be described. In this embodiment, the relationship between the heat dissipation member 40 and the mold resin 50 is changed with respect to the first embodiment, and the other parts are the same as those in the first embodiment. Only explained.

  As shown in FIG. 3, in the present embodiment, the upper surface of the heat radiating member 40 protrudes from the upper surface 50 a of the mold resin 50. That is, the heat dissipation member 40 is higher than the upper surface 50 b of the mold resin 50 from the one surface 11 of the substrate 10.

  Thus, even when the upper surface of the heat dissipation member 40 protrudes from the mold resin 50, the same effect as that of the first embodiment can be obtained.

  In such a configuration, for example, as in the second embodiment, while the upper surface of the heat radiating member 40 is covered with the mold resin 50, the mold resin 50 is placed on the front surface of the upper surface 50a by laser removal or the like in a later step. This can be realized by removing the thickness. At this time, for the portion where the heat radiating member 40 exists, the amount of removal of the heat radiating member 40 is smaller than that of the resin, so that the upper surface of the heat radiating member 40 protrudes from the upper surface of the mold resin 50. In this manner, a mold package provided in the electronic device according to the present embodiment can be configured.

(Fourth embodiment)
A fourth embodiment of the present invention will be described. In the present embodiment, the arrangement of the electronic component 30 is changed with respect to the first to third embodiments, and the other aspects are the same as those of the first to third embodiments, and thus the first to third embodiments. Only different parts will be described. FIG. 4 shows a structure in which the arrangement of the electronic components 30 is changed with respect to the first embodiment, but the same applies to the second and third embodiments.

  As shown in FIG. 4, in this embodiment, the electronic component 30 is disposed on the other surface 12 side of the substrate 10. Specifically, the conductor layer 16 constituting a part of the land or the wiring pattern is formed on the other surface 12 side, and the electronic component 30 is arranged on the conductor layer 16 via a joining member 31 such as solder. . Some elements constituting the electronic component 30 are difficult to seal in the mold resin 50. For example, when the electronic component 30 is a spiral capacitor, if the electronic component 30 is disposed in the mold resin 50, a problem such as a change in the electrode interval of the capacitor due to stress at the time of curing of the resin or a short circuit between the electrodes may occur. . In such a case, it is preferable to dispose the electronic component 30 outside the mold resin 50 instead of sealing the electronic component 30 in the mold resin 50.

  Therefore, as in the present embodiment, by disposing the electronic component 30 outside the mold resin 50 in the substrate 10, it is possible to suppress problems due to the electronic component 30 being disposed in the mold resin 50. Become. In addition, although the electronic component 30 can be arranged on the one surface 11 side of the substrate 10, if the electronic component 30 is disposed on the one surface 11 side, the area of the substrate 10 is increased. For this reason, by arranging the electronic component 30 on the other surface 12 side of the substrate 10 as in this embodiment, in addition to obtaining the above effects, it is possible to reduce the area of the substrate 10. It becomes.

  Further, there may be a form in which heat generated by the electronic component 20 is released by arranging a heat sink or the like on the other surface 12 side of the substrate 10. However, in the case where the electronic component 30 is arranged on the other surface 12 side, there may be a case where the arrangement space for the heat sink cannot be secured. If the area of the substrate 10 is enlarged, a heat sink arrangement space can be secured, but the meaning of arranging the electronic component 30 on the other surface 12 side is lost. For this reason, when it is set as the form where the electronic component 30 is arrange | positioned at the other surface 12 like this embodiment, it is especially possible to perform heat radiation from the one surface 11 side of the board | substrate 10 by the heat radiating member 40. It is valid.

(Other embodiments)
The present invention is not limited to the embodiment described above, and can be appropriately changed within the scope described in the claims.

  For example, in each of the above-described embodiments, an electronic device to which the electronic components 20 and 30 are mounted on the one surface 11 of the substrate 10 and then the electronic components 20 and 30 and the heat dissipation member 40 are sealed with the mold resin 50 is applied. However, the structure may not be the one described in each of the above embodiments. For example, as an example of the heat generating member, the electronic component 20 composed of a heat generating element has been described as an example. However, a wiring through which a large current flows is also a heat generating member. For this reason, a wiring through which a large current flows may be connected to the conductor layer 14 so that heat generated from the wiring is released through the heat dissipation member 40. In that case, the conductor layer 14 may be used as part of the wiring through which a large current flows.

10 Substrate 11 One side 12 Other side 13, 14 Conductor layer (first and second conductor layers)
20, 30 Electronic component 40 Heat dissipation member 50 Mold resin

Claims (5)

A substrate (10) having one surface (11) and another surface (12) opposite to the one surface, which is made of an insulating material and has a first conductor layer (13) formed on the one surface;
A heating member (20) disposed on one side of the substrate;
A lower surface (50a) provided on one surface side of the substrate and serving as one surface side of the substrate, an upper surface (50b) serving as a surface opposite to the lower surface, and a side surface (50c) connecting the lower surface and the upper surface. A mold resin (50) for sealing the heat generating member,
A via (15) formed from one surface of the substrate to the inside of the substrate at a position where the heat generating member is disposed on one surface of the substrate;
A second conductor layer (14) formed in the substrate and connected to the via and extending in a plane direction of the substrate from a position facing the heating member;
Provided on one side of the substrate, facing a portion of the second conductor layer extending in the horizontal direction from the position facing the heat generating member of the second conductor layer across an insulating material serving as a base of the substrate An electronic device comprising: a heat dissipating member (40) which is disposed and extends toward the upper surface of the mold resin and is made of a material having a higher thermal conductivity than the mold resin.   The electronic device according to claim 1, wherein the heat radiating member is exposed from an upper surface of the mold resin.   The said heat radiating member is coat | covered with the said mold resin, The thickness of the part which has coat | covered the said heat radiating member among the said mold resin is 0.5 mm or less, The Claim 1 characterized by the above-mentioned. Electronic equipment. The heat generating member is mounted on the first conductor layer,
The portion of the first conductor layer on which the heat generating member is mounted is thermally and electrically connected to the second conductor layer through the via. The electronic device according to one.   The electronic device according to claim 1, wherein an electronic component is mounted on the other surface side of the substrate.

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