JP2019096746A - Electronic equipment - Google Patents

Abstract

To realize high heat dissipation in electronic equipment mounting a semiconductor module not having ground potential.SOLUTION: In electronic equipment including a semiconductor module 1, a multilayer substrate 2 mounting it, and an enclosure component 3 housing the multilayer substrate 2, an island 101 mounting a semiconductor element 11, out of the semiconductor module 1, is connected with a surface heat transfer body 22 connected thermally and electrically with the enclosure component 3, out of the multilayer substrate 2, via an insulation heat transmission layer 12. With such an arrangement, a heat radiation path for transmitting heat of the semiconductor module 1 to the enclosure component 3 only through a material of high heat conductivity in the multilayer substrate 2 is formed, and electronic equipment of higher heat dissipation than conventional electronic equipment is obtained, while making the semiconductor module 1 electrically independent from the portion of ground potential.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an electronic device mounted on, for example, an automobile or the like.

  2. Description of the Related Art Conventionally, in an electronic device provided with a heating element such as a semiconductor element, a structure for efficiently radiating heat generated from the heating element has been proposed. For example, a heating element, a circuit board on which the heating element is mounted on one side, a heat sink disposed on the other side of the circuit board, and a housing component for housing these are formed on the circuit board The electronic device of the structure which thermally radiates the heat of a heat generating body to a heat sink via the through-hole vias is mentioned. However, since this type of electronic device has a structure in which the number of parts increases by the amount of heat sinks and the size of the housing parts for accommodating the circuit board is increased, it is preferable from the viewpoint of the demand for smaller electronic devices in recent years. Absent.

  Then, the electronic device which is not equipped with a heat sink and has high heat dissipation is proposed, for example, the thing of patent document 1 is mentioned as such an electronic device. The electronic device described in Patent Document 1 includes a heat generating body having a heat dissipation electrode, a circuit board having the heat generating body mounted therein, and an inner layer heat transfer body therein, and containing the inner layer heat transfer body and heat. And electrically connected housing parts. In this electronic device, in the thickness direction of the circuit board, the heat dissipation electrode and the inner-layer heat transfer body overlap each other with the insulating layer forming the circuit board being separated. As a result, after the heat generated from the heat generating body is transferred to the inner layer heat transfer body, the heat is dissipated to the casing component connected thereto, thereby providing an electronic device having a high heat dissipation property without the heat sink.

JP 2008-130684 A

  Here, in the electronic device described in Patent Document 1, the heat dissipation electrode of the heat generating body is set to a positive potential, and the inner layer heat transfer body connected to the casing component and the circuit board is set to a ground potential. The inner layer heat transfer body electrically connects the heat dissipation electrode and the heat generating body through the insulating layer constituting the circuit board in order to prevent the case parts connected to other parts from becoming a positive potential. It is insulated. Such an insulating layer is made of, for example, a resin material such as glass epoxy resin, which has high insulation and low thermal conductivity. Therefore, when the heat generated from the heat generating body is dissipated to the casing component, the heat is transmitted to the inner layer heat transfer body through the resin material having a small thermal conductivity, and this becomes the rate limiting of the heat dissipation in the circuit board.

  That is, in an electronic device provided with a semiconductor element such as a rectifying diode and a heating element electrically insulated from a member having the ground potential, the heating element and a portion of the circuit board electrically connected to the housing component are It is set as the structure separated by the insulating layer with small heat conductivity. Therefore, the heat dissipation in the circuit board is reduced.

  As a method of enhancing the heat dissipation in the circuit board, the area of the conducting part connected to the heat generating member in the circuit board is enlarged to increase the efficiency of heat conduction between the conducting part and the inner layer heat transfer body. The insulating layer may be made of a material having a high thermal conductivity.

  However, in the former method, there is a concern that radiation noise may increase due to the wide pattern of the current-carrying member, and the mounting of the circuit board may be restricted, which may deteriorate the mounting performance. On the other hand, in the latter method, the material of the insulating layer is limited, which causes an increase in cost.

  In addition, when the heat dissipation property of the circuit board is not enhanced, it is conceivable to make the heat generating body more difficult to generate heat or to improve heat resistance, but with this method, the size increase and cost increase of the heat generating body become problems.

  The present invention has been made in view of the above-mentioned point, and the heat generated from the heat generating body is efficiently dissipated to the casing component while being provided with the heat generating body electrically insulated from the member to be the ground potential. An object of the present invention is to provide an electronic device having higher heat dissipation than in the past.

  In order to achieve the above object, an electronic device according to claim 1 comprises a semiconductor module (1) and a multilayer substrate (2) having one surface on which the semiconductor module is mounted, and a housing component (3) for housing the multilayer substrate And. In such a configuration, the semiconductor module includes the island (101) and the semiconductor element (11) mounted on the island via the insulating heat transfer layer (12), and the multilayer substrate is insulated A layer (20), a conducting wire (21) electrically connected to the semiconductor element, a surface heat transfer body (22) disposed on one side of the insulating layer, and a layer disposed in the insulating layer An inner layer heat transfer body (23) and a via (24) connecting the surface heat transfer body and the inner layer heat transfer body are provided, and the surface heat transfer body is electrically insulated from the current-carrying wiring It is electrically and electrically connected to the island and the housing parts, and is at ground potential.

  As a result, the heat generated from the semiconductor module which is a heat generating member is transferred to the island through the insulating heat transfer layer, and thereafter, it becomes an electronic device having a structure in which the heat is dissipated from the surface heat transfer body or the inner layer heat transfer body . In addition, the semiconductor module is prevented from being at the ground potential while being thermally connected to the island at the ground potential. Therefore, the semiconductor device does not have the ground potential, and the electronic device has higher heat dissipation than in the related art.

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

It is a sectional view showing an electronic device of a 1st embodiment. It is a plane schematic diagram which shows the arrangement | positioning relationship between the multilayer substrate in 1st Embodiment, and a heat generating body. It is sectional drawing which shows the electronic device of 2nd Embodiment. It is sectional drawing which shows the conventional electronic device. It is sectional drawing which shows the electronic device of other embodiment.

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

First Embodiment
The electronic device of the first embodiment will be described with reference to FIGS. 1 and 2. In FIG. 1, in order to make the configuration easy to understand, the thicknesses of the insulating heat transfer layer 12, the conducting wire 21, the surface heat transfer body 22 and the like described later are exaggerated and shown, and I-I shown by a dashed dotted line in FIG. The corresponding cross section is shown. In FIG. 2, for the same purpose as FIG. 1, although the cross section is not shown, the insulating layer 20 described later is hatched.

  The electronic device of the present embodiment is applied to an electronic device such as an air bag ECU (abbreviation of Electronic Control Unit) mounted on a vehicle such as a car, for example.

  As shown in FIG. 1, the electronic device of the present embodiment includes a semiconductor module 1, a multilayer substrate 2, and a housing part 3 for housing these.

  As shown in FIG. 1, the semiconductor module 1 includes a lead frame 10, a semiconductor element 11, an insulating heat transfer layer 12, a wire 13, and a mold resin 14, and a solder (not shown) on the multilayer substrate 2. It is mounted via etc. As shown in FIG. 1, the semiconductor module 1 has a so-called half mold structure in which the surface of the lead frame 10 opposite to the surface on which the semiconductor element 11 is mounted is exposed from the mold resin 14. The semiconductor module 1 is a rectifying diode in this embodiment, and has a known configuration except that the insulating heat transfer layer 12 is used.

  The semiconductor module 1 as a rectifying diode is a member through which a current of, for example, several A flows, and its current value is large and its heat generation amount is large as compared with semiconductor parts such as a transistor used for a high frequency circuit. Therefore, the semiconductor module 1 is mounted on the multilayer substrate 2 so as to be dissipated to the outside from the casing component 3 mainly through the insulating heat transfer layer 12 and the multilayer substrate 2 described later. It is kept at a temperature that can operate.

  For example, as shown in FIG. 1, the lead frame 10 includes an island 101 on which the semiconductor element 11 is mounted, and a lead 102 electrically connected to the semiconductor element 11. It is made of a metal material or an alloy thereof.

  The semiconductor element 11 is mounted on one surface of the island 101 via an insulating heat transfer layer 12 described later. The island 101 is a portion which is electrically insulated from the semiconductor element 11 by the insulating heat transfer layer 12 and from which the heat generated from the semiconductor element 11 is dissipated. As shown in FIG. 1, in the island 101, the surface opposite to the surface on which the semiconductor element 11 is mounted is exposed from the mold resin 14, and this opposite surface will be described later in the multilayer substrate 2 through solder or the like not shown. It is connected to the surface heat transfer body 22.

  As shown in FIG. 1, the lead 102 is electrically connected to an electrode (not shown) formed on the semiconductor element 11 through the wire 13. As shown in FIG. 1, a part of the lead 102 is exposed from the mold resin 14, and is connected to a current-carrying wiring 21 of the multilayer substrate 2 via a solder (not shown).

  The semiconductor element 11 functions as, for example, a diode, and is mainly made of a semiconductor material such as Si. The semiconductor element 11 is formed by, for example, a normal semiconductor process.

  The insulating heat transfer layer 12 is a member that electrically insulates the island 101 and the semiconductor element 11 from each other and thermally connects them. The insulating heat transfer layer 12 has a structure having both insulating properties and thermal conductivity, for example, aluminum nitride or silicon carbide having high insulating properties and high thermal conductivity in insulating resin materials such as epoxy resin and silicone resin. And other fillers.

  The insulating heat transfer layer 12 may be made of any material that is compatible with the semiconductor material and the metal material while having both insulation and thermal conductivity, and is not limited to the above example. May be

  For example, as shown in FIG. 1, the wire 13 is connected to an electrode pad and a lead 102 (not shown) formed on the surface of the semiconductor element 11 on the opposite side of the island 101 by wire bonding or the like. Made of high-grade metal material.

  As shown in FIG. 1, the mold resin 14 covers the semiconductor element 11, a part of the lead frame 10 and the wires 13, and is made of, for example, an arbitrary resin material such as an epoxy resin.

  The multilayer substrate 2 includes, as shown in FIG. 1, an insulating layer 20, a conducting wire 21, a surface heat transfer body 22, an inner layer heat transfer body 23, a via 24, and a back surface heat transfer body 25. The semiconductor module 1 is mounted on one side. As shown in FIG. 1, in the multilayer substrate 2, through holes 26 for fixing the housing component 3 and the bolt 33 are formed. The multilayer substrate 2 is manufactured by a process of forming a general through multilayer substrate, for example, alternately stacking and pressing a sheet of insulating resin such as glass epoxy resin and a sheet of conductive material such as copper foil. Ru.

  In addition to the semiconductor module 1, the multilayer substrate 2 is formed with other electronic components (not shown), its control circuit, and the like on one surface side on which the semiconductor module 1 is mounted. The type, number, arrangement, and the like of these other electronic components may be changed as appropriate, and are arbitrary, and thus the detailed description thereof is omitted here.

  The insulating layer 20 is made of, for example, a laminate of an arbitrary insulating resin such as a glass epoxy resin as a result of the process of forming a general through multilayer substrate.

  The conducting wire 21 is disposed on one surface 20 a of the insulating layer 20 as shown in FIG. 1 and is electrically connected to the lead 102 via a solder (not shown) to drive the semiconductor element 11. Used for The conducting wire 21 is electrically connected to a first wire 211 electrically connected to an anode (not shown) of the semiconductor element 11 and a cathode (not shown) of the semiconductor element 11 as shown in FIG. 1 or 2. And a second wiring 212.

  The first wiring 211 and the second wiring 212 are, for example, an external power supply or other electronic components (not shown) mounted on one surface of the multilayer substrate 2 at the other end opposite to one end connected to the semiconductor module 1 And are electrically connected. Specifically, among the wires 211 and 212, the wires electrically connected to the anode of the semiconductor element 11 are connected by soldering or the like to lead wires connected to an external power supply (not shown). Among the wires 211 and 212, the wires electrically connected to the cathode of the semiconductor element 11 are lead wires (not shown) disposed on one surface of the multilayer substrate 2 and connected to other electronic components and control circuits thereof. It is connected by soldering etc. The first wire 211 and the second wire 212 are electrically independent of each other, and are connected to the housing part 3 to form the surface heat transfer body 22, the inner layer heat transfer body 23, the via 24 and the back surface which are set to the ground potential. It is electrically independent of the heat transfer body 25.

  Note that lead wires (not shown) connected to an external power supply are formed to connect the inside and the outside of the case 31 of the casing components 3 described later, and are electrically insulated from the case 31. With such a connection structure, the semiconductor module 1 can be driven as a rectifying diode while being electrically independent of the housing part 3.

  The surface heat transfer body 22 is disposed on one surface 20 a of the insulating layer 20 as shown in FIG. 1 and is connected to the island 101 via a solder or the like not shown, and the inner layer heat transfer via the via 24. Connected to the body 23 In the present embodiment, for example, as shown in FIG. 2, the surface heat transfer body 22 has a substantially rectangular plate shape in which an opening 221 surrounding the conduction wire 21 in plan view and a bolt hole 222 are formed. . As shown in FIG. 1, the surface heat transfer body 22 is in contact with the case 31 by fixing the case 31 and the cover 32 constituting the housing component 3 by pressure contact with the multilayer substrate 2 and the bolt 33. The surface heat transfer body 22 is electrically insulated from the conduction wiring 21 and is thermally connected to the island 101, the inner layer heat transfer body 23 and the housing component 3.

  The surface heat transfer body 22 is electrically insulated from the current-carrying wiring 21 and other not-shown other electronic components and the like electrically connected thereto, and the insulation other than the opening 221 is necessary for this insulation. Other openings may be provided separately. The opening 221 has a quadrangular shape as viewed in the normal direction to the one surface 20 a of the insulating layer 20, but it is preferable that the surface heat transfer member 22 be electrically insulated from the conduction wiring 21. It may be circular, oval or other shape. The same applies to the other openings when the surface heat transfer body 22 is formed with the other openings.

  The inner layer heat transfer body 23 is, for example, in a rectangular plate shape, and a plurality of inner layer heat transfer bodies 23 are formed in the insulating layer 20 as shown in FIG. In the present embodiment, the inner-layer heat transfer body 23 is stacked via the insulating layer 20 and disposed in parallel to the plane formed by the surface heat transfer body 22, and the surface heat transfer body 22 and the back surface via the via 24. The heat transfer body 25 is electrically and thermally connected. The inner layer heat transfer body 23 transfers the heat of the semiconductor module 1 transferred to the front surface heat transfer body 22 to the back surface heat transfer body 25 and diffuses in the plane direction orthogonal to the thickness direction of the multilayer substrate 2 It is a member for improving the heat dissipation of 2. The two inner layer heat transfer members 23 are disposed in parallel in the insulating layer 20 in the present embodiment, but the number may be changed as appropriate.

  For example, the via 24 has a configuration in which a through hole connecting one surface 20 a of the insulating layer 20 to the other surface 20 b is filled with a material such as Cu or Ag having high thermal and electrical conductivity. The vias 24 are formed by an optional through hole via formation method for thermally and electrically connecting different conductors in a common multilayer substrate or the like. In the present embodiment, as shown in FIG. 1, the vias 24 are disposed at least in a region of the multilayer substrate 2 located immediately below the island 101 (hereinafter referred to as “the region immediately below the island”). That is, the vias 24 thermally and electrically connect the surface heat transfer body 22, the inner layer heat transfer body 23, and the back surface heat transfer body 25 at least in a region immediately below the island.

  In addition, as shown in FIG. 1, the vias 24 are also provided in the vicinity of the connection region with the housing component 3 in the multilayer substrate 2 from the viewpoint of the heat dissipation improvement of the multilayer substrate 2, and the surface heat transfer body 22 and the inner layer The heat transfer body 23 and the back surface heat transfer body 25 are thermally and electrically connected. The vias 24 may be disposed at least in the region directly under the island and the region directly below the surface heat transfer body 22 connected to the housing part 3, and the other regions may be arbitrarily disposed. Of the vias 24, those disposed in the region directly below the surface heat transfer body 22 connected to the housing component 3 are positioned as close as possible to the housing component 3 from the viewpoint of improving the heat dissipation of the multilayer substrate 2. Is preferred. Further, in the present embodiment, in the cross section shown in FIG. 1, a total of eight vias 24 are provided in the region directly under the island and two each in the vicinity of two connection regions with the housing component 3 in the multilayer substrate 2. Although provided, it is suitably changed according to the amount of heat transfer with the housing part 3 or the like.

  The back surface heat transfer body 25 is, for example, in the form of a rectangular plate, and is disposed on the other surface 20 b of the insulating layer 20 as shown in FIG. Are held and fixed by the bolts 33 so as to be in contact with the cover 32 constituting the housing part 3.

  The current-carrying wiring 21, the surface heat transfer body 22, the inner layer heat transfer body 23, and the back surface heat transfer body 25 are made of, for example, a conductive material such as Cu.

  For example, as shown in FIG. 1, the housing part 3 accommodates the multilayer substrate 2, and in the present embodiment, a case 31 connected with an external member 4 such as a car body, and a cover 32. Have.

  The case 31 is made of, for example, a metal material such as Al or an alloy thereof, and in the present embodiment, as shown in FIG. 1, one side of the multilayer substrate 2 on which the semiconductor module 1 is mounted is covered. Is located in As illustrated in FIG. 1, bolt holes 311 are formed in the case 31, and the case 31 is in contact with the surface heat transfer body 22 by being held and fixed to the multilayer substrate 2 by the bolts 33. The case 31 is a cooling member that receives the heat generated from the semiconductor module 1 through the multilayer substrate 2 and discharges the heat to the outside of the multilayer substrate 2, for example, the body of an automobile. As shown in FIG. 1, the case 31 is electrically connected to an external member 4 such as a car body, and is set to a ground potential. The case 31 covers the one surface side of the multilayer substrate 2 to shield electrical noise generated by energization of the semiconductor module 1 and to suppress an adverse effect due to radiation of noise to the outside.

  In the present embodiment, the cover 32 is made of, for example, a metal material such as Al or an alloy thereof, and is disposed on the opposite side of the case 31 across the multilayer substrate 2 as shown in FIG. It is arrange | positioned so that the other side opposite to one side of 2 may be covered. As shown in FIG. 1, the cover 32 is formed with bolt holes 321, and is fixed to the multilayer substrate 2 together with the case 31 by the bolts 33 so as to be in contact with the back surface heat transfer body 25. In the present embodiment, the cover 32 covers the other surface side of the multilayer substrate 2 and plays a role of suppressing an adverse effect of external radiation caused by noise caused by energization of the semiconductor module 1 as in the case 31.

  The case 31 and the cover 32 are arranged such that the bolt holes 311 and 321 overlap at the same position when viewed in the normal direction to one surface of the multilayer substrate 2 on which the semiconductor module 1 is mounted, and sandwich the multilayer substrate 2 Is pressed and fixed by a bolt 33 or the like.

  The housing part 3 may be thermally connected to the multilayer substrate 2 while housing the multilayer substrate 2 so that the heat generated from the semiconductor module 1 can be dissipated, without being limited to the above example. The configuration, shape, etc. may be changed as appropriate. Moreover, the connection structure of the housing component 3 and the multilayer substrate 2 is not limited to the above example, and may be appropriately changed.

  The above is the configuration of the electronic device of the present embodiment. That is, in the electronic device of this embodiment, the heat generated from the semiconductor module 1 is transferred to the surface heat transfer body 22 through the insulating heat transfer layer 12, and thereafter, the casing component from the inner layer heat transfer body 23 through the via 24. It is transmitted to 3 and finally dissipated to the outside. The external member 4 is used to electrically and thermally connect the electronic component of the present embodiment, and is, for example, a metal component such as a body of an automobile, and is made of Al or the like.

  Next, although an example of the manufacturing method of the electronic device of this embodiment will be described, an arbitrary method can be adopted except that the insulating heat transfer layer 12 is used in the semiconductor module 1, and therefore, will be briefly described here. . In addition, since the arrangement of the electronic components and the control circuit other than the semiconductor module 1 disposed on the multilayer substrate 2 is arbitrary, the description thereof is omitted in the present specification.

  First, a semiconductor element 11 functioning as a rectifying diode, a lead frame 10 provided with islands 101 and leads 102, and an insulating high thermal conductivity material constituting the insulating heat transfer layer 12 are prepared.

  Subsequently, the material of the insulating heat transfer layer 12 is applied on the island 101 by, for example, a dispenser, and then the semiconductor element 11 is placed and cured. Then, an electrode (not shown) formed on the semiconductor element 11 is electrically connected to the lead 102 by wire bonding using a wire 13 made of Au or the like.

  Thereafter, a mold (not shown) is prepared, the workpiece after wire bonding is set in the mold, and a resin material such as epoxy resin is poured into the mold and cured to form the mold resin 14. Thus, the semiconductor element 11 can be mounted on the island 101 via the insulating heat transfer layer 12, and the semiconductor module 1 of the half mold type can be manufactured.

  Then, the multilayer substrate 2 is prepared which includes the conducting wire 21, the surface heat transfer body 22, the inner layer heat transfer body 23, the via 24 and the back surface heat transfer body 25 and the through holes 26 to which the bolts 33 are fastened later. . The semiconductor module 1 is mounted on the multilayer substrate 2 by, for example, solder, to electrically connect the conducting wire 21 and the lead 102, and thermally and electrically connect the island 101 and the surface heat transfer body 22. .

  Subsequently, the multi-layer board 2 on which the semiconductor module 1 is mounted is accommodated, and the case component 3 including the case 31 and the cover 32 in which the bolt holes 311 or 321 to which the bolts 33 are fastened is formed is prepared. The housing part 3 and the multilayer substrate 2 are held and fixed by fastening the bolt 33.

  The electronic device of the present embodiment is manufactured, for example, by the method as described above, and is used by being connected to the external member 4.

  Next, the improvement of the heat dissipation by the electronic device of the present embodiment will be described with reference to FIG. 1, FIG. 2, and FIG.

  First, a conventional electronic device will be briefly described with reference to FIG. 4 shows an exaggeration of the thicknesses of the current-carrying wiring 21, the surface heat transfer body 22, the inner layer heat transfer body 23, and the back surface heat transfer body 25 as in FIG. The same reference numerals are given to components equivalent to the components in the electronic device of the present embodiment. Further, in FIG. 4, a portion corresponding to the cross section shown in FIG. 1 is shown, and in order to make the difference with the electronic device of the present embodiment intelligible, the casing part 3 and the exterior common to the electronic device of the present embodiment The member 4 of is omitted.

  The conventional electronic device comprises a semiconductor module 5 and a multilayer substrate 2 on which the semiconductor module 5 is mounted, as shown in FIG. In the conventional electronic device, the heat of the semiconductor module 5 which is a rectifying diode is transmitted to the multilayer substrate 2, the housing part 3 and the external member 4 in this order and dissipated to the outside. The conventional electronic device is different from the electronic device of the present embodiment in that there is a portion where the structure of the semiconductor module 5 is different from that of the semiconductor module 1. The differences will be mainly described below.

  As shown in FIG. 4, the semiconductor module 5 includes the lead frame 10 including the island 101 and the leads 102, the semiconductor element 11, the solder 51, the wire 13, and the mold resin 14. In the semiconductor module 5, the semiconductor element 11 is mounted on the island 101 via the solder 51, and the surface of the island 101 opposite to the surface on which the semiconductor element 11 is mounted is covered with the mold resin 14. Is different from the semiconductor module 1.

  In the conventional electronic device, as shown in FIG. 4, the semiconductor module 5, which is a rectifying diode, is separated by the surface heat transfer body 22 set to the ground potential and the mold resin 14, whereby the ground potential of the multilayer substrate 2 is obtained. It is configured to be electrically independent of the site taken. In the conventional electronic device, as shown in FIG. 4, the heat of the semiconductor module 5 is transmitted from the island 101 or the wiring 21 for current conduction to the inner layer heat transfer body 23 of the multilayer substrate 2, and thereafter the member 4 outside the housing part 3 It is supposed to be transmitted to

  However, in the conventional electronic device, when the heat of the semiconductor module 5 is transferred to the inner layer heat transfer body 23, the mold resin 14 or the insulating layer 20 formed of a resin material having a thermal conductivity lower than that of the inner layer heat transfer body 23 It is an intervening structure. In other words, the conventional electronic device has a configuration in which the heat transfer at the portion where the thermal conductivity is low is rate-determining in the heat dissipation path from the semiconductor module 1 to the multilayer substrate 2.

  The material constituting the mold resin 14 and the insulating layer 20, for example, an epoxy resin or a glass epoxy resin, has a thermal conductivity, for example, as compared with the thermal conductivity (about 390 W / mK) of Cu constituting the inner layer heat transfer body 23 and the like. The conductivity is very small, about 0.2 to 0.3 W / mK. Therefore, the heat dissipation of these members having a low thermal conductivity is rate-limiting, which causes the reduction of the heat dissipation of the entire electronic device.

  On the other hand, in the electronic device of the present embodiment, as shown in FIG. 1, the heat of the semiconductor module 1 is transmitted to the surface heat transfer body 22 through the insulating heat transfer layer 12 having both insulation and thermal conductivity. The configuration, that is, the configuration in which there is no rate limitation of heat radiation by the mold resin 14 described above. In the electronic device according to the present embodiment, the heat dissipation in the multilayer substrate 2 is increased by that amount, so the heat dissipation is higher than in the conventional electronic device.

  According to the present embodiment, the semiconductor module 1 is mounted via the insulating heat transfer layer 12 and the portion which becomes the ground potential by being connected to the housing component 3 in the multilayer substrate 2. While being thermally connected to the ground potential portion, they are electrically independent. As a result, the heat of the semiconductor module 1 is transmitted to the inner layer heat transfer body 23 through the material with high thermal conductivity without the semiconductor element 11 being set to the ground potential, so that the heat dissipation property is higher than that of the conventional electronic device. It becomes an electronic device.

  The current value of the rectifier diode mounted in this type of electronic device is conventionally about 2 A, but due to the recent demand for integration of other electronic components, control circuits, etc. on the multilayer substrate 2, etc. It may be required to be larger (e.g. 3A or more). As the current value increases, the amount of heat generated by the rectifying diode also increases, so the heat dissipation in the multilayer substrate needs to be increased accordingly. Even in such a case, the electronic device of the present embodiment efficiently transfers the heat of the semiconductor module 1 to the multilayer substrate 2 without changing the wiring pattern of the multilayer substrate 2 to a dedicated pattern or the like in consideration of heat dissipation. It becomes a structure to be transmitted.

Second Embodiment
The electronic device of the second embodiment will be described with reference to FIG. Similar to FIG. 1, FIG. 3 shows the exaggeration of the thicknesses of the current-carrying wiring 21, the surface heat transfer body 22, the inner layer heat transfer body 23 and the back surface heat transfer body 25 and is common to the first embodiment. The housing part 3 and the external member 4 are omitted. Further, FIG. 3 shows a portion corresponding to the cross section shown in FIG.

  The electronic device according to the present embodiment is, as shown in FIG. 3, the point that the multilayer substrate 6 having a configuration not having a portion corresponding to the via 24 is used instead of the multilayer substrate 2. And electronic devices. In the present embodiment, this difference is mainly described. The same reference numerals are given to components corresponding to the components of the electronic device of the first embodiment among the electronic devices of the present embodiment.

  In the electronic device of the present embodiment, as shown in FIG. 3, the semiconductor module 1 is mounted on a multilayer substrate 6 having no via.

  As shown in FIG. 3, the semiconductor module 1 is connected to the current-carrying wiring 21 and the surface heat transfer body 22 formed on the insulating layer 20 constituting the multilayer substrate 6 by solder (not shown). In the present embodiment, since the vias are not provided in the multilayer substrate 6, the heat of the semiconductor element 11 is mainly transmitted in the order of the insulating heat transfer layer 12, the island 101, the surface heat transfer body 22, and the housing component 3 There is.

  According to the present embodiment, the heat of the semiconductor element 11 is transmitted to the casing component 3 mainly through the surface heat transfer body 22 in the multilayer substrate 6 so that the semiconductor module 1 is not set to the ground potential, and the heat is dissipated. It becomes a highly electronic device.

(Other embodiments)
In addition, the electronic device shown in each above-mentioned embodiment shows an example of the electronic device of this invention, It is not limited to each above-mentioned embodiment, It is in the range described in the claim. It is possible to change as appropriate.

  (1) For example, in the first embodiment, the portion of the surface heat transfer body 22 connected to the island 101 (hereinafter referred to as “island connection portion”) is, as shown in FIG. An example was described in which the configuration was connected to other parts. However, the island connection portion may be connected to at least one of the other portion of the surface heat transfer body 22 or the inner layer heat transfer body 23 through the material having high thermal conductivity, and integrated with the other portion. The shape does not have to be the same. For example, the island connection portion may have the same plane size as the island 101 when viewed in the normal direction to the one surface 20 a of the insulating layer 20 and may be isolated from other portions of the surface heat transfer body 22. . In this case, the heat of the semiconductor module 1 is transmitted from the island connection portion to the inner layer heat transfer body 23 and the casing component 3 through the vias 24, so that the heat dissipation in the multilayer substrate 2 can be secured.

  (2) In the first embodiment, the case where the housing part 3 is formed of the case 31 and the cover 32 and the cover 32 is formed of a metal material has been described. However, the housing part 3 has a member made of a metallic material which is connected to a portion of the multilayer substrate 2 which is thermally and electrically connected to the island 101 and connected to the external member 4. It only needs to be configured. Therefore, when the case 31 is made of a metal material and connected to the external member 4, the cover 32 may be made of a material different from the metal material, such as a resin material. In the above case, the housing part 3 may be configured without the cover 32.

  In the first embodiment, the case 31 of the housing component 3 is connected to the external member 4 and the cover 32 is not connected to the external member 4. However, the connection relationship is reversed. It may be

  Specifically, the housing part 3 has a case 31 and a cover 32 made of a metal material, and as shown in FIG. 5, the cover 32 is connected to the external member 4 and the case 31 may not be connected to the external member 4. In the electronic device in this case, the heat generated in the semiconductor module 1 is transmitted to the cover 32 in the order of the surface heat transfer body 22, the via 24, and the back surface heat transfer body 25 and dissipated to the external member 4 through the cover 32. Be done. In this case, the case 31 may be made of a metal material, or may be made of a material different from the metal material.

  (3) In each of the above embodiments, an example in which the multilayer substrate 2 or the multilayer substrate 6 is configured to include the back surface heat transfer body 25 has been described. However, the multilayer substrate 2 or the multilayer substrate 6 only needs to include the surface heat transfer body 22 connected to at least the island 101 of the semiconductor module 1 and the housing component 3, and does not need to include the back surface heat transfer body 25. Good.

  (4) Although the example of the multilayer substrate 6 in which the via is not formed is described in the second embodiment, the via may be formed in the multilayer substrate 6 other than the region immediately below the island 101.

  (5) In each of the above embodiments, an example in which the semiconductor module 1 is a rectifying diode has been described. However, semiconductor components that can not be connected to the ground potential, such as a linear regulator transistor, may be used.

Reference Signs List 1 semiconductor module 101 island 11 semiconductor element 12 insulating heat transfer layer 2 multilayer substrate 20 insulating layer 21 wiring for current application 22 surface heat transfer body 23 inner layer heat transfer body 3 housing component

Claims (4)

A semiconductor module (1) and a multilayer substrate (2) having one surface on which the semiconductor module is mounted;
And a housing part (3) for housing the multilayer substrate,
The semiconductor module includes an island (101) and a semiconductor element (11) mounted on the island via an insulating heat transfer layer (12).
The multilayer substrate includes an insulating layer (20), a conducting wire (21) electrically connected to the semiconductor element, and a surface heat transfer body (22) disposed on the one surface side of the insulating layer. And an inner layer heat transfer body (23) disposed in the insulating layer, and a via (24) connecting the surface heat transfer body and the inner layer heat transfer body,
The electronic device, wherein the surface heat transfer body is electrically insulated from the current-carrying wiring, is thermally and electrically connected to the island and the housing component, and has a ground potential.   The said via is arrange | positioned in the area | region located directly under the said island among the said multilayer board | substrates at least, and has connected the said surface heat transfer body and the said inner-layer heat transfer body thermally and electrically. Electronic device as described.   The electronic device according to claim 1, wherein the housing component covers the one surface side of the multilayer substrate and the other surface side opposite to the one surface side. The electronic device according to any one of claims 1 to 3, wherein the semiconductor device is a rectifying diode.

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