JP6887476B2 - Semiconductor power module - Google Patents

Description

The present application relates to the structure of a semiconductor power module.

As the semiconductor power module using a semiconductor element, a transfer mold type power module in which the semiconductor element is sealed with a thermosetting resin such as an epoxy resin and a gel-sealed type power module in which the semiconductor element is sealed with a gel-like resin are used. There is.

In the transfer mold type power module, the electrical connection between the semiconductor element and the electrode is mainly performed by wire bonding. On the other hand, in gel-sealed power modules, a connection method called DLB (Direct-Lead-Bonding) in which a semiconductor element and an electrode are directly bonded is often used, and recently, DLB is mainly used for connection with a semiconductor. Further, a power module structure for performing transfer mold encapsulation using a wire bonding connection has also been developed (Patent Document 1).

Japanese Unexamined Patent Publication No. 2014-36077

In Patent Document 1, the electrode and the semiconductor element are connected by using both the DLB connection and the wire bonding connection. In the structure in which they are transfer-molded and sealed, the electrodes for wire bonding must be provided with a jig under the bonding portion, and these are outside on the mounting surface of the base electrode on which the semiconductor element is mounted. It is necessary to arrange the electrodes, and there is a problem that the entire module becomes large.

This is because the wire bonding process requires a lower jig that receives the load applied from the wire bonding device to the bonding wire or vibrations such as ultrasonic waves at the time of bonding. , The joint cannot receive the load required for bonding or vibration such as ultrasonic waves well, the bonding between the bonding wire and the electrode becomes poor, and there is a risk that reliability such as breakage in the manufacturing process will decrease. Because.

The present application has been made in view of the above problems, and an object of the present application is to provide a semiconductor power module provided with an electrode capable of wire bonding even on a mounting surface of a base electrode on which a semiconductor element is mounted. ..

The semiconductor power module disclosed in the present application includes a first electrode, a semiconductor element provided on the first electrode, an insulating member provided on the first electrode, and the insulating member. A second electrode provided via the wire and having a wire bonding joint with the semiconductor element, a third electrode bonded on the semiconductor element, and a fourth electrode connected to the first electrode. The second electrode is provided with an electrode, and the joint portion of the second electrode is disposed above the insulating member that supports the second electrode, and the insulating member supports the second electrode and the first. It is provided between the electrode of the above and the third electrode, and between the first electrode and the fourth electrode, and supports the third electrode and the fourth electrode.

According to the present application, a second electrode is provided via an insulating member provided on the first electrode, and a wire bonding joint with the semiconductor element is above the insulating member that supports the second electrode. Since it is arranged, it is possible to have a second electrode capable of wire bonding on the mounting surface of the first electrode. Therefore, it is possible to realize a highly reliable joint portion that can sufficiently receive the load required for the joint portion of the wire bonding or the vibration such as ultrasonic waves without increasing the size of the entire module.

It is a schematic diagram which shows the structure of the semiconductor power module in Embodiment 1, (A) is a plan view, (B) is a front view. It is a schematic diagram which shows the structure of the semiconductor power module in Embodiment 2, (A) is a plan view, (B) is a sectional view along the line AA in the plan view (A). It is a schematic diagram which shows the structure of the semiconductor power module in Embodiment 3, (A) is a plan view, (B) is a sectional view along the line AA in the plan view (A). It is a schematic diagram which shows the structure of the semiconductor power module in Embodiment 4, (A) is a plan view, (B) is a sectional view along the line AA in the plan view (A). It is a front schematic diagram which shows the structure of the semiconductor power module in Embodiment 5.

Embodiment 1.
1A and 1B are schematic views showing the structure of the semiconductor power module according to the first embodiment of the present application, FIG. 1A shows a plan view, and FIG. 1B shows a front view. In FIGS. 1A and 1B, the semiconductor power module 100 has a semiconductor element 1, a first electrode 2 serving as a base electrode on which the semiconductor element 1 is provided on the upper surface, and a control signal from the outside to the semiconductor element 1. The second electrode 3 that transmits the above, the third electrode 4 that is the output terminal that takes out the output of the semiconductor element 1 to the outside, and the fourth electrode that is connected to the first electrode 2 and is the input terminal that receives the input from the outside. It has 5. The fourth electrode 5 is folded in an L shape at the position of the broken line in the figure and is connected to the first electrode 2. Further, a second electrode 3 is provided on the first electrode 2 via an insulating member 6. The second electrode 3 and the semiconductor element 1 are connected by a bonding wire 7 at a bonding portion 7a. The joint portion 7a is arranged above the insulating member 6 that supports the second electrode 3 on the mounting surface of the first electrode 2. Further, these components are sealed by the sealing resin 8. For convenience of explanation, FIGS. 1A and 1B are shown in a state where the sealing resin 8 is transparent.

As the semiconductor element 1, for example, a power semiconductor element such as a power control semiconductor element such as an IGBT (Insulated Gate Bipolar Transistor) or a MOSFET (Metal-Oxide-Semiconductor Field-Effective Transistor) is used. In addition to the silicon semiconductor element, the semiconductor element 1 includes a wide bandgap semiconductor having a larger bandgap than silicon, such as silicon nitride or gallium nitride, and has a high allowable current density that can be applied and also has a power loss. Since it is low, the semiconductor power module 100 can be miniaturized.

In FIG. 1, only one semiconductor element 1 is mounted in one power module, but the present invention is not limited to this, and a required number of semiconductor elements 1 may be mounted depending on the intended use. It is possible. Further, the semiconductor element 1 and the first electrode 2 are bonded by, for example, a solder, Ag nanoparticles, a sintering agent composed of Cu nanoparticles, or the like.

The first electrode 2, the second electrode 3, the third electrode 4, and the fourth electrode 5 are semiconductors by using a metal material having high thermal conductivity and excellent heat dissipation, such as copper or a copper alloy. The power module 100 can be miniaturized. The surface of the first electrode 2 opposite to the mounting surface of the semiconductor element 1 is exposed from the sealing resin 8, and the heat generated by the semiconductor element 1, the third electrode 4, and the fourth electrode 5 is generated. Is radiating heat.

The third electrode 4 is bonded to the upper surface of the semiconductor element 1 by, for example, solder (not shown), and the fourth electrode 5 is bonded to the periphery of the mounting portion of the semiconductor element 1 of the first electrode 2, for example, by solder. (Not shown), and the third electrode 4 and the fourth electrode 5 are taken out from the side surface direction of the sealing resin 8. In FIG. 1, the sealing resin 8 is taken out from only one direction of the side surface, but the method of taking out each electrode is not limited to this, and the side surface or the upper surface may be taken out in another direction. Regarding the electrical connection method inside the semiconductor power module 100, the semiconductor element 1 and the third electrode 4 and the first electrode 2 and the fourth electrode 5 are joined by solder, but a current having a required current density can be obtained. The connection method is not particularly limited as long as it can be flowed.

The second electrode 3 is connected to the upper surface of the semiconductor element 1 by a bonding wire 7, and the bonding portion 7a between the second electrode 3 and the bonding wire 7 is second on the mounting surface of the first electrode 2. The electrodes 3 of the above are present in the region of the surface facing each other. The insulating member 6 sandwiched between the second electrode 3 and the first electrode 2 receives a load from a bonding device or vibration such as ultrasonic waves in a bonding process while ensuring insulation between these electrodes. , Has a function as a support member for supporting the joint portion 7a of the second electrode 3. By providing such a structure, the second electrode 3 can be arranged on the mounting surface of the first electrode 2, and the semiconductor power module 100 can be miniaturized.

Further, on the mounting surface of the first electrode 2, the bonding portion 7a of the insulating member 6 and the second electrode 3 supported by the insulating member 6 is provided near the semiconductor element 1 to shorten the length of the bonding wire 7. As a result, the rigidity of the bonding wire 7 is increased, the reliability is improved, and the distance is shortened, so that the inductance of the bonding wire 7 can be suppressed and the semiconductor power module 100 can be driven at a high frequency.

Further, if the insulating member 6 is fixed to both the first electrode 2 and the second electrode 3 by, for example, using an adhesive, it is possible to prevent misalignment and fall off in the manufacturing process of the semiconductor power module 100. It also becomes.

As the material of the insulating member 6, if an insulating resin having an insulating property such as a thermosetting resin is used, the effect as a supporting member can be obtained. Further, if a material containing a ceramic material such as an insulating member 6 having high thermal conductivity 6 such as alumina, aluminum nitride, or silicon nitride is used, the heat dissipation effect of the semiconductor power module 100 can be enhanced. Further, if the insulating sheet has adhesiveness, the electrodes can be fixed to each other without using an adhesive, so that the manufacturing time can be shortened.

Further, by integrally molding the second electrode 3 and the insulating member 6 with, for example, PPS (Poly Phene sulfide Resin), the accuracy of the position and height of the second electrode 3 with respect to the first electrode 2 can be improved. it can.

Embodiment 2.
The second embodiment is a modification of the first embodiment, and FIG. 2 shows a schematic diagram showing the structure of the semiconductor power module according to the second embodiment. (A) is a plan view, and (B) is a cross-sectional view taken along line AA in the plan view (A). As shown in FIG. 2, in the semiconductor power module 200, the insulating member 6 sandwiched between the first electrode 2 and the second electrode 3 is stretched, and the insulating member 6 is the first electrode 2 and the third electrode 2. It is provided between the electrode 4 and the electrode 4.

Even in such a shape, the effect as a support member can be obtained as in the first embodiment, and the material of the insulating member 6 is used as an insulating material having high thermal conductivity as in the first embodiment. As a result, the heat generated by the semiconductor element 1 can be dissipated from the first electrode 2 via the connected third electrode 4 and the insulating material 6, so that the heat dissipation path of the semiconductor element 1 can be increased, resulting in high cooling. The effect can be obtained.

Even if the insulating member 6 and the first electrode 2, the second electrode 3, and the third electrode 4 are in contact with each other, the same effect as that of the first embodiment can be obtained as a support member in the bonding step. Further, by adhering the third electrode 4 and the first electrode 2 via the insulating member 6, for example, the thermal resistance becomes smaller than in the state of contact, and the effect of improving the heat dissipation performance is obtained. Be done.

Further, by integrally molding the second electrode 3, the third electrode 4, and the insulating member 6 with, for example, PPS, the positions and heights of the second electrode 3 and the third electrode 4 with respect to the first electrode 2 are obtained. The accuracy of the electrode can be increased.

Embodiment 3.
The third embodiment is a modification of the first embodiment, and FIG. 3 shows a schematic diagram showing the structure of the semiconductor power module according to the third embodiment. (A) is a plan view, and (B) is a cross-sectional view taken along line AA in the plan view (A). As shown in FIG. 3, in the semiconductor power module 300, an insulating member 6 is also provided between the first electrode 2 and the fourth electrode 5.

Even in such a shape, the effect as a support member can be obtained as in the first embodiment, and further, by using the material of the insulating member 6 as an insulating material having high thermal conductivity, the fourth electrode The effect of dissipating the heat generated by 5 from the first electrode 2 via the insulating material 6 can be obtained.

Even if the insulating member 6, the first electrode 2, the second electrode 3, and the fourth electrode 5 are in contact with each other, the same effect as that of the first embodiment can be obtained as a support member in the bonding step. Further, by adhering the insulating member 6, the fourth electrode 5, and the first electrode 2 with, for example, an adhesive, the thermal resistance becomes smaller than in the state of contact, and the effect of improving heat dissipation performance can be obtained. ..

Further, by integrally molding the fourth electrode 5, the second electrode 3, and the insulating member 6 with, for example, PPS, the positions and heights of the fourth electrode 5, the second electrode 3, and the first electrode 2 are obtained. The accuracy of can be increased.

Embodiment 4.
The fourth embodiment is a modification of the first embodiment, and FIG. 4 shows a schematic diagram showing the structure of the semiconductor power module according to the fourth embodiment. (A) is a plan view, and (B) is a cross-sectional view taken along line AA in the plan view (A). As shown in FIG. 4, in this semiconductor power module 400, the insulating member 6 sandwiched between the first electrode 2 and the second electrode 3 is placed between the first electrode 2 and the third electrode 4. And extends between the first electrode 2 and the fourth electrode 5.

Even in such a shape, the effect as a support member can be obtained as in the first embodiment, and further, by using the material of the insulating member 6 as an insulating material having high thermal conductivity, the first embodiment 1 Needless to say, the heat dissipation effect of the semiconductor element 1, the first electrode 2, the third electrode 4, and the fourth electrode 5 described in the second embodiment and the third embodiment can be obtained.

The insulating member 6 and the first electrode 2, the second electrode 3, the third electrode 4, and the fourth electrode 5 are in contact with each other as in the first embodiment as a support member in the bonding step. The effect of is obtained. Further, for example, by adhering with an adhesive, the adhesion between the electrodes is improved, and the effect of improving the heat dissipation of the third electrode 4 and the fourth electrode 5 can be obtained.

Further, by integrally molding the second electrode 3, the third electrode 4, the fourth electrode 5, and the insulating member 6 with, for example, PPS, the second electrode 3, the third electrode 4, and the second electrode are formed. The accuracy of the position and height of the four electrodes 5 with respect to the first electrode 2 can be improved.

Embodiment 5.
The fifth embodiment is a modification of the first embodiment, and FIG. 5 shows a schematic view of the structure of the semiconductor power module according to the fifth embodiment as viewed from the front. However, for convenience of explanation, the sealing resin 8 is shown in a transparent state. As shown in FIG. 5, in the semiconductor power module 500, a metal plate 10 is arranged on the opposite side (lower side) of the mounting surface of the first electrode 2 with an insulating layer 9 interposed therebetween. As the insulating layer 9, for example, an insulating sheet in which an epoxy resin is filled with an inorganic powder such as silica or alumina having excellent thermal conductivity can be used.

Further, the surface of the metal plate 10 opposite to the joint surface with the insulating layer 9 is exposed from the sealing resin 8, and also serves as a protective layer to prevent the insulating layer 9 from being damaged by external contact. As long as this object is satisfied, the material is not particularly limited, and a metal plate such as copper or aluminum or a metal foil can be applied. With this configuration, it is possible to insulate and protect the bottom portion of the semiconductor module 500 while maintaining the heat dissipation effect. Even with such a configuration, the insulating member 6 sandwiched between the second electrode 3 and the first electrode 2 may be subjected to a load from a bonding device in the bonding process or vibration such as ultrasonic waves. This makes it possible to maintain good bondability between the third electrode 4 and the bonding wire 7.

Needless to say, the structure of the insulating layer 9 and the metal plate 10 shown in the fifth embodiment can be used in the first to fourth embodiments so far.

In the first to fifth embodiments, the number of mounted semiconductor elements 1, the first electrode 2, the second electrode 3, the third electrode 4, the fourth electrode 5, and the insulating member 6 is for illustration purposes. Although shown by a limited example, the present invention is not limited to this, and the same one semiconductor power module 100, 200, 300, 400, 500 can be equipped with a required number as needed. Further, the insulating member 6 may be divided into electrodes as needed, or a plurality of electrodes may be mounted on one insulating member 6.

Although the present application describes various exemplary embodiments and examples, the various features, embodiments, and functions described in one or more embodiments are applications of a particular embodiment. It is not limited to, but can be applied to embodiments alone or in various combinations. Therefore, innumerable variations not illustrated are envisioned within the scope of the techniques disclosed herein. For example, it is assumed that at least one component is modified, added or omitted, and further, at least one component is extracted and combined with the components of other embodiments.

1 Semiconductor element, 2 1st electrode, 3 2nd electrode, 4 3rd electrode, 5 4th electrode, 6 Insulation member, 7 Bonding wire, 7a junction, 8 Encapsulating resin, 9 Insulation layer, 10 Metal plate, 100,200,300,400,500 semiconductor power module

Claims (6)

With the first electrode,
A semiconductor element provided on the first electrode and
An insulating member provided on the first electrode and
Provided via the insulating member
A second electrode having a wire bonding joint with the semiconductor element,
With the third electrode bonded on the semiconductor element,
With the fourth electrode connected to the first electrode,
With
The joint portion of the second electrode is disposed above the insulating member that supports the second electrode.
The insulating member supports the second electrode and also supports the second electrode.
It is provided between the first electrode and the third electrode, and between the first electrode and the fourth electrode, and supports the third electrode and the fourth electrode. A semiconductor power module featuring. Said insulating member, said first electrode, said second electrode, the semiconductor power module according to claim 1 which is bonded between the front Symbol third electrode, and the fourth electrode. The semiconductor power module according to claim 1 or 2, wherein a metal plate is provided under the first electrode via an insulating layer. The semiconductor power module according to any one of claims 1 to 3, wherein the insulating member is an insulating resin. The semiconductor power module according to any one of claims 1 to 4, wherein the insulating member is an insulating sheet. The semiconductor power module according to any one of claims 1 to 5, wherein the insulating member contains a ceramic material.

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