JP2021040113A - Semiconductor device - Google Patents

Abstract

To provide a semiconductor device with high heat dissipation.SOLUTION: A semiconductor device 10 includes a lead frame 20 including one surface 21a, a power element 30, a sealing resin body 50, and a re-wiring part 60. The power element 30 includes, as main electrodes, a drain electrode 32 formed on the one surface 21a side and electrically connected to the lead frame 20, and a source electrode 31 formed on the opposite surface. The sealing resin body 50 is disposed on the one surface 21a and seals the power element 30 with the one surface 21a. The re-wiring part 60 includes an insulator 61 stacked on the sealing resin body 50, and wires provided on the insulator 61. The wires include, as main wires 63 electrically connected to the main electrodes, a source wire 64 a part of which is exposed from an opening 61b provided to the insulator 61 and forms an external electrode 64e.SELECTED DRAWING: Figure 2

Description

The disclosure herein relates to semiconductor devices.

Patent Document 1 describes a semiconductor device in which a semiconductor element is arranged on one surface of a lead frame and the semiconductor element is resin-sealed together with one surface. The contents of the prior art document are incorporated by reference as an explanation of the technical elements in this specification.

Japanese Unexamined Patent Publication No. 2016-31948

In Patent Document 1, a semiconductor element having a vertical structure having main electrodes on the front surface and the back surface is used. The back electrode of the semiconductor element is electrically connected to a wiring member (die pad) via a bonding material. Therefore, the heat generated by the semiconductor element can be dissipated to the back surface side via the wiring member. The surface electrodes of the semiconductor element are connected to the terminals via wires. The resin encapsulant integrally encloses a part of the terminal, the element mounting surface and side surface of the wiring member, the semiconductor element, and the wire. Since the resin sealant is provided so as to cover the wire, the thermal resistance on the surface side is large. Further improvements are required of semiconductor devices in the above-mentioned viewpoints or in other viewpoints not mentioned.

One object disclosed is to provide a semiconductor device with high heat dissipation.

The semiconductor device disclosed herein is
Wiring members (20, 120, 220) having one surface (21a, 121a, 221a) and
A semiconductor element arranged on one surface, which is formed as a main electrode on the back surface electrode (32) formed on the one surface side and electrically connected to the wiring member, and on the surface opposite to the back surface electrode. A power element (30) having a surface electrode (31) and
A sealing resin body (50) that is arranged on one surface of the wiring member and seals the power element together with the one surface.
An insulator (61) laminated on a sealing resin body and a wiring provided in the insulator, which is electrically connected to the main electrode and partly provided in the insulator (61b). A rewiring portion (60) having a main wiring (63) exposed from the outside to form an external electrode, and
With
The main wiring includes a surface electrode wiring (64) electrically connected to the surface electrode.

According to the disclosed semiconductor device, a wiring member is connected to the back electrode of the power element. Therefore, the heat of the power element can be dissipated to the back surface side via the wiring member. On the other hand, the surface electrode wiring (main wiring) of the rewiring portion is connected to the surface electrode. A part of the surface electrode wiring is exposed from an opening provided in the insulator to form an external electrode. Therefore, the heat of the power element can be dissipated to the surface side via the surface electrode wiring. Further, since the bonding wire is not used, the thickness of the semiconductor device, particularly the thickness of the sealing resin body on the surface electrode of the power element can be reduced. This also makes it possible to reduce the thermal resistance on the surface side and improve the heat dissipation. As a result, it is possible to provide a semiconductor device having high heat dissipation.

The disclosed aspects herein employ different technical means to achieve their respective objectives. The claims and the reference numerals in parentheses described in this section exemplify the correspondence with the parts of the embodiments described later, and are not intended to limit the technical scope. The objectives, features, and effects disclosed herein will be made clearer by reference to the subsequent detailed description and accompanying drawings.

It is a top view which shows the semiconductor device which concerns on 1st Embodiment. It is sectional drawing which follows the line II-II of FIG. It is sectional drawing which shows the manufacturing method of a semiconductor device. It is sectional drawing which shows the manufacturing method of a semiconductor device. It is sectional drawing which shows the semiconductor device which concerns on 2nd Embodiment. It is sectional drawing which shows the modification. It is sectional drawing which shows the semiconductor device which concerns on 3rd Embodiment. It is sectional drawing which shows the modification. It is a schematic diagram around a semiconductor element in the semiconductor device which concerns on 4th Embodiment. It is sectional drawing which shows the semiconductor device which concerns on 5th Embodiment. It is sectional drawing which shows the semiconductor device which concerns on 6th Embodiment. It is sectional drawing which shows the semiconductor device which concerns on 7th Embodiment. It is sectional drawing which shows the cooling structure of a semiconductor device. It is sectional drawing which shows the sealing method of a clip. It is a schematic cross-sectional view which shows the structure of the clip in the semiconductor device which concerns on 8th Embodiment.

Hereinafter, a plurality of embodiments will be described with reference to the drawings. In a plurality of embodiments, functionally and / or structurally corresponding parts and / or related parts may be designated with the same reference code or reference numerals having a hundreds or more different digits. References can be made to the description of other embodiments for the corresponding and / or associated parts.

(First Embodiment)
First, the structure of the semiconductor device will be described with reference to FIGS. 1 and 2. The semiconductor device is mounted on a vehicle, for example, and is used for electric power control.

<Structure of semiconductor device>
As shown in FIGS. 1 and 2, the semiconductor device 10 includes a lead frame 20, a power element 30, a circuit element 40, a sealing resin body 50, and a rewiring portion 60. The semiconductor device 10 is sometimes referred to as a semiconductor package. In the following, the thickness direction of the semiconductor element is referred to as the Z direction. Further, one direction orthogonal to the Z direction, specifically, the alignment direction of the power element 30 and the circuit element 40 is indicated as the X direction. Then, the direction orthogonal to the Z direction and the X direction is referred to as the Y direction. Unless otherwise specified, the shape along the XY plane defined by the X direction and the Y direction is simply referred to as a plane shape. Further, the plan view from the Z direction is simply referred to as a plan view. In FIG. 2, the protective film on the surface of the semiconductor element is omitted.

The lead frame 20 is a metal member made of Cu or the like. The lead frame 20 is a wiring member that is electrically connected to the power element 30 and functions as wiring. The lead frame 20 has a base portion 21 and a protrusion 22 extending from one surface 21a of the base portion 21 to the rewiring portion 60 side. A power element 30 and a circuit element 40 are arranged on one surface 21a of the base portion 21. One surface 21a is a mounting surface for a semiconductor element in the lead frame 20. The protrusion 22 extends from one surface 21a to a position higher than the surface of the semiconductor element. The base 21 has a back surface 21b opposite to the one surface 21a in the Z direction.

In the present embodiment, the lead frame 20 is not a flat plate having a substantially uniform plate thickness, but a deformed strip having a partially different plate thickness. The plate thickness is the length in the Z direction. The base portion 21 has a thin-walled portion 210 and a thick-walled portion 211 which is a portion thicker than the thin-walled portion 210. A circuit element 40 is arranged in the thin-walled portion 210, and a power element 30 is arranged in the thick-walled portion 211. The back surface 21b is flush with the thin portion 210 and the thick portion 211. The back surface 21b is a plane whose entire surface is substantially orthogonal to the Z direction. The position of the one surface 21a is different between the thin portion 210 and the thick portion 211 in the Z direction. One surface 21a is a plane substantially orthogonal to the Z direction in each of the thin-walled portion 210 and the thick-walled portion 211.

The thin-walled portion 210 and the thick-walled portion 211 are provided side by side in the X direction, which is the longitudinal direction of the lead frame 20 (base portion 21). A thin-walled portion 210 is provided on one end side of the base portion 21, and a thick-walled portion 211 is provided on the other end side. A connecting portion whose plate thickness gradually changes is interposed between the thin portion 210 and the thick portion 211. The protruding portion 22 protrudes from a position different from the mounting portion of the power element 30 in the thick portion 211. The protrusion 22 is provided so as to have a gap between the protrusion 22 and the power element 30 in a plan view. The protrusion 22 and the power element 30 are aligned in the X direction in a plan view. The protrusion 22 is provided near the end of the lead frame 20 in the longitudinal direction. In the X direction, the power element 30 is arranged between the protrusion 22 and the circuit element 40. The protrusion 22 is a columnar body having a substantially rectangular plane. The protrusion 22 is provided so as to straddle (cross) the power element 30 in the Y direction.

In the lead frame 20, the plate thickness T1 of the portion including the protrusion 22 is thicker than the plate thicknesses T2 and T3 of the portion on which the semiconductor element is mounted. T2 is the plate thickness of the thin-walled portion 210, and T3 is the plate thickness of the thick-walled portion 211 other than the portion where the protrusions 22 are continuous. T1 is the sum of the plate thickness T3 of the thick portion 211 and the thickness of the protrusion 22 with respect to one surface 21a. Further, an insulating layer 24 is provided on the back surface 21b. The entire back surface 21b is protected by the insulating layer 24. The insulating layer 24 is formed by using an electrically insulating material such as resin.

The power element 30 and the circuit element 40 may be referred to as a semiconductor element or a semiconductor chip. The power element 30 is a semiconductor chip in which an element having a vertical structure is formed on a semiconductor substrate such as silicon (Si), silicon carbide (SiC), or gallium nitride (GaN). The power element 30 has main electrodes on both sides in the Z direction, which is the plate thickness direction. An electric current flows between the main electrodes. The power element 30 has a front electrode which is a main electrode on the rewiring portion 60 side and a back electrode which is a main electrode on the lead frame 20 side (one side 21a side). In the following, the surface on the rewiring portion 60 side will be referred to as the front surface, and the surface on the lead frame 20 side will be referred to as the back surface. The power element 30 is arranged on the lead frame 20 so that the back surface faces the surface 21a.

In this embodiment, a MOSFET is formed as an element having a vertical structure. The power element 30 has a source electrode 31 which is a front surface electrode, a drain electrode 32 which is a back surface electrode, and a pad 33. The pad 33 is a signal electrode formed at a position different from that of the source electrode 31 on the surface. The pad 33 includes a gate pad for applying a drive voltage to the gate electrode of the MOSFET. A plurality of elements (MOSFETs) corresponding to a plurality of channels (ch) are formed on the semiconductor substrate. Specifically, elements for 2 channels are formed. The semiconductor substrate has a plurality of active regions corresponding to the number of channels.

The drain electrode 32 is formed on the entire back surface of the power element 30, and is common to a plurality of channels. The source electrode 31 is formed corresponding to the active region and is divided for each channel. As shown in FIG. 1, the power element 30 has two source electrodes 31, and the two source electrodes 31 are provided side by side in the Y direction. The pad 33 is also formed for each channel. The pad 33 is formed in the power element 30 near the end on the circuit element 40 side.

The power element 30 is fixed to one surface 21a of the lead frame 20 (base 21) via a bonding material 34. The drain electrode 32 of the power element 30 is electrically connected to the lead frame 20 via the bonding material 34. The heat generated by the power element 30 is transferred to the lead frame 20 via the bonding material 34. Therefore, as the bonding material 34, a bonding material having excellent conductivity and thermal conductivity, such as a sintered body of solder, Au, and Ag, can be used.

Pillars 35 are formed on the electrodes on the surface side of the power element 30, that is, the source electrodes 31 and the pads 33. The pillar 35 is a columnar body formed of a metal material such as Cu, and is electrically connected to an electrode directly below the pillar 35. The pillar 35 corresponds to a metal columnar body. A plurality of pillars 35 are formed for each of the source electrodes 31. The plurality of pillars 35 are dispersedly arranged on the source electrode 31. The pillar 35 is formed on the pad 33 to which the signal wiring 66 is connected.

The circuit element 40 is a semiconductor chip in which a drive circuit for the power element 30 is formed on a semiconductor substrate. The circuit element 40 is sometimes referred to as an IC chip. The circuit element 40 is, for example, an ASIC. The circuit element 40 has a pad 43 on a surface that is the same side as the source electrode 31. Like the pad 33, the pad 43 is a signal electrode. In the present embodiment, the plurality of pads 43 are arranged along the outer peripheral edge of the surface of the circuit element 40, and the entire plurality of pads 43 form a discontinuous substantially rectangular annular shape. The circuit element 40 does not have an electrode on the back surface. The circuit element 40 is arranged on the lead frame 20 so that the back surface faces the surface 21a.

The circuit element 40 is fixed to one surface 21a of the lead frame 20 via a bonding material 44. No electrode is formed on the back surface of the circuit element 40, and the amount of heat generated by the circuit element 40 is smaller than that of the power element 30 which is a heat generating element. Therefore, a resin-based adhesive such as Ag paste may be used as the bonding material 44.

Pillars 45 are also formed on the pads 43 of the circuit element 40. The pillar 45 has the same structure as the pillar 35 and corresponds to a metal columnar body. The pillar 45 is formed on the pad 43 to which the signal wirings 66 and 67 are connected. The tip surface of the pillar 45 is substantially flush with the tip surface of the protrusion 22 and the tip surface of the pillar 35 in the Z direction.

The sealing resin body 50 is arranged on one surface 21a of the lead frame 20, and seals the semiconductor element (power element 30 and circuit element 40) together with the one surface 21a. The sealing resin body 50 is formed of, for example, an epoxy resin. The sealing resin body 50 is molded by using, for example, a transfer molding method or a compression molding method. The sealing resin body 50 covers almost the entire surface of one surface 21a. In the lead frame 20, the back surface 21b side is exposed from the sealing resin body 50.

The sealing resin body 50 has a surface 50a which is a surface opposite to the connecting surface (adhesive surface) with the one surface 21a. The surface 50a is almost entirely flat. The surface 50a is substantially flush with the tip surface of the protrusion 22 and the tip surfaces of the pillars 35 and 45. The tip surface of the protrusion 22 and the tip surfaces of the pillars 35 and 45 are exposed from the sealing resin body 50 in a state of being substantially flush with the surface 50a. The protrusion 22 penetrates the sealing resin body 50.

The rewiring portion 60 is arranged on the sealing resin body 50. The rewiring portion 60 has an insulator 61 laminated on the surface 50a of the sealing resin body 50, and wiring provided on the insulator 61. The rewiring unit 60 may be referred to as a rewiring layer. The insulator 61 includes an insulating layer 62 formed of a material such as polyimide or BPO (polybenzoxazole). The insulator 61 has a surface 61a which is a surface opposite to the connecting surface (adhesive surface) of the sealing resin body 50 with the surface 50a. The wiring is formed by using a metal having good conductivity such as Cu.

The wiring includes a main wiring 63 that is electrically connected to the main electrode. The main wiring 63 has a source wiring 64 and a drain wiring 65. The source wiring 64 is electrically connected to the source electrode 31 via a pillar 35. The rewiring unit 60 has source wiring 64 for 2 channels. The drain wiring 65 is electrically connected to the drain electrode 32 via a lead frame 20 including a protrusion 22 and a bonding material 34. The source wiring 64 corresponds to the front electrode wiring, and the drain wiring 65 corresponds to the back electrode wiring.

The insulator 61 is provided with openings 61b and 61c that open to the surface 61a. A part of the main wiring 63 is exposed from the openings 61b and 61c to form an external electrode that can be connected to the outside. The insulator 61 has two openings 61b for the source wiring 64 for 2 channels and one opening 61c for the drain wiring 65. The two source wirings 64 each have an external electrode 64e. The drain wiring 65 has an external electrode 65e. The external electrodes 64e and 65e are recessed with respect to the surface 61a of the insulator 61. The external electrodes 64e and 65e may be referred to as external terminals.

In the present embodiment, the insulator 61 is configured by arranging the insulating layers 62 in multiple layers. Specifically, three insulating layers 62 are laminated to form an insulator 61. The wiring is arranged in multiple layers with respect to the insulator 61. The source wiring 64 includes a via conductor 64v, and the drain wiring 65 includes a via conductor 65v. The via conductor is a conductor arranged by a plating method or the like in a via hole (through hole) formed in the insulating layer 62. The via conductors 64v and 65v are sometimes referred to as interlayer connecting portions and interlayer connecting vias.

The via conductor 64v is formed corresponding to the pillar 35 on the source electrode 31. The via conductor 64v is formed at a position overlapping the pillar 35 on the source electrode 31 in a plan view. As shown in FIG. 1, a plurality of via conductors 64v are dispersedly arranged with respect to each of the source electrodes 31. The via conductor 64v is provided on the first and second insulating layers 62 from the sealing resin body 50 side. An opening 61b is formed in the third layer, that is, the insulating layer 62 forming the surface 61a. The opening 61b penetrates the third layer of the insulating layer 62, and a plurality of via holes formed in the second layer of the insulating layer 62 are connected to the bottom surface of the opening 61b. It can be said that the opening 61b is a via hole having a larger opening area than the via holes formed in the first and second layers.

The opening 61b has a planar rectangle with the X direction as the longitudinal direction, and includes the source electrode 31 in a plan view. The wiring of the third layer arranged in the opening 61b forms the external electrode 64e. The planar shape of the external electrode 64e substantially coincides with the opening 61b. The external electrode 64e includes the corresponding source electrode 31 in a plan view. The source electrode 31 is connected to the external electrode 64e located directly above the pillar 35 and the via conductor 64v extending in the Z direction. One end of the source wiring 64 is connected to the source electrode 31 via a pillar 35, and the other end forms an external electrode 64e.

The via conductor 65v is formed at a position overlapping the protrusion 22 in a plan view. The via conductor 65v is provided on the first and second insulating layers 62. An opening 61c is formed in the third insulating layer 62. The opening 61c penetrates the third layer of the insulating layer 62 and is connected to the via hole formed in the second layer of the insulating layer 62. In a plan view, the opening 61c and the via hole substantially coincide with the tip surface of the protrusion 22. It can be said that the opening 61c is a via hole having an opening area substantially equal to that of the via holes formed in the first and second layers. The wiring of the third layer arranged in the opening 61c forms the external electrode 65e. The planar shape of the external electrode 65e substantially coincides with the opening 61c. The protrusion 22 of the lead frame 20 is connected to the external electrode 65e located directly above the via conductor 65v extending in the Z direction.
One end of the drain wiring 65 is connected to the drain electrode 32 via a lead frame 20 including a protrusion 22, and the other end forms an external electrode 65e.

The rewiring unit 60 further includes signal wirings 66 and 67 as wiring. The signal wiring 66 is a wiring that electrically connects the power element 30 and the circuit element 40. The signal wiring 67 is wiring that electrically connects the circuit element 40 and an external device, for example, an ECU that outputs a drive command to the circuit element 40. The signal wiring 66 electrically connects the corresponding pads 33 and 43. The signal wiring 67 is electrically connected to the pad 43, and a part of the signal wiring 67 is exposed from the opening 61d of the insulator 61 to form an external electrode 67e. The opening 61d is open to the surface 61a like the openings 61b and 61c. The signal wiring 66 includes a via conductor 66v, and the signal wiring 67 includes a via conductor 67v.

The via conductor 66v is formed at a position overlapping the pillars 35 and 45 on the pads 33 and 43 corresponding to the signal wiring 66. The via conductor 66v is provided on the first insulating layer 62. Then, the corresponding via conductor 66v is connected by the wiring of the second layer. The signal wiring 66 is covered with a third insulating layer 62.

The via conductor 67v is formed at a position overlapping the pillar 45 on the pad 43 corresponding to the signal wiring 67. The via conductor 67v is provided on the first insulating layer 62. An opening 61d is formed in the third insulating layer 62. The wiring of the third layer arranged in the opening 61d forms the external electrode 67e. The external electrode 67e and the via conductor 67v are connected by the wiring of the second layer. The external electrodes 67e are exposed from the insulator 61 at both ends in the Y direction.

<Manufacturing method of semiconductor devices>
Next, the manufacturing method of the above-mentioned semiconductor device 10 will be described with reference to FIGS. 3 and 4. 3 and 4 correspond to FIG. In FIGS. 3 and 4, some elements are omitted while being partially simplified with respect to FIG.

First, as shown in FIG. 3A, a semiconductor element on which pillars 35 and 45 are formed is prepared. A power element 30 in which a pillar 35 is formed on a source electrode 31 and a pad 33 (not shown) and a circuit element 40 in which a pillar 45 is formed on a pad 43 (not shown) are prepared. In this embodiment, the lengths of the pillars 35 and 45 extending from the electrodes are different from each other. Specifically, the length of the pillar 45 of the circuit element 40 arranged on the thin-walled portion 210 in the subsequent process is made longer than the length of the pillar 35 of the power element 30 arranged on the thick-walled portion 211.

Next, as shown in FIG. 3B, the semiconductor element is arranged on one surface 21a of the lead frame 20 (base 21). At this time, a lead frame 20 having a deformed strip having a protrusion 22 is prepared. Then, the power element 30 is fixed to the one surface 21a on the thick portion 211 of the base portion 21 via a joining material 34 (not shown). That is, the drain electrode 32 (not shown) is connected to the lead frame 20. Further, the circuit element 40 is fixed to one surface 21a on the thin-walled portion 210 via a joining material 44 (not shown).

Next, as shown in FIG. 3C, the sealing resin body 50 is molded. The sealing resin body 50 is formed on one surface 21a of the lead frame 20 so as to seal the power element 30 and the circuit element 40 on each surface 21a. At this time, the sealing resin body 50 is molded so as to cover the entire protrusions 22, pillars 35, and 45.

Next, as shown in FIG. 4A, the sealing resin body 50 is scraped from the surface 50a side to make it thinner. At this time, the sealing resin body 50 is cut and ground so that the protrusions 22 and the pillars 35 and 45 are exposed.

For example, it is preferable to control the amount of scraping so that the back surface 21b to the front surface 50a of the lead frame 20 have a predetermined thickness. At that time, at least one of the protrusion 22 and the pillars 35 and 45 may be cut and ground together with the sealing resin body 50. Even if there are variations in the thickness of the lead frame 20, variations in the thickness of the semiconductor elements, variations in the lengths of the pillars 35 and 45, and errors in assembling the semiconductor elements, the surface 50a, the tip surface of the protrusion 22, and the tip of the pillars 35 and 45 The faces can be substantially flush. In the present embodiment, the protrusions 22 and the pillars 35 and 45 are cut and ground together with the sealing resin body 50.

Next, as shown in FIG. 4B, the rewiring portion 60 is formed. The rewiring portion 60 can be formed by known wiring techniques such as photolithography, plating and the like. An insulating layer 62 (not shown) is laminated on the sealing resin body 50 to form an insulator 61, and the insulator 61 is provided with a main wiring 63 including a source wiring 64 and a drain wiring 65, and signal wirings 66 and 67. Provide. A part of the source wiring 64 is exposed from the opening 61b to the surface 61a side to form an external electrode 64e. A part of the drain wiring 65 is exposed from the opening 61c to the surface 61a side to form an external electrode 65e.

Finally, as shown in FIG. 4C, the insulating layer 24 is formed on the back surface 21b of the lead frame 20. From the above, the semiconductor device 10 can be obtained.

<Summary of the first embodiment>
In the present embodiment, the power element 30 is arranged on one surface 21a of the lead frame 20. The power element 30 is sealed together with one side 21a by the sealing resin body 50. Since the drain electrode 32 formed on the back surface of the power element 30 is connected to the lead frame 20, the heat generated by the power element 30 is dissipated to the outside via the lead frame 20 and further to the lead frame 20. Can be done. That is, the heat of the power element 30 can be dissipated to the back surface side of the semiconductor device 10.

Further, a rewiring portion 60 including a source wiring 64 is provided as wiring on the surface 50a of the sealing resin body 50. One end of the source wiring 64 is electrically connected to the source electrode 31 formed on the surface of the power element 30, and the other end is exposed from the opening 61b to form the external electrode 64e. Therefore, the heat of the power element 30 can be dissipated to the outside through the source wiring 64 and further, the source wiring 64. That is, the heat of the power element 30 can be dissipated to the surface side of the semiconductor device 10.

Further, since the bonding wire is not used, the thickness of the semiconductor device 10, particularly the thickness of the sealing resin body 50 on the source electrode 31 of the power element 30, can be reduced. This also makes it possible to reduce the thermal resistance on the surface side and improve the heat dissipation. With the double-sided heat dissipation structure described above, the heat dissipation of the semiconductor device 10 can be improved.

Further, in the present embodiment, the circuit element 40 is also arranged on one surface 21a of the lead frame 20, and the circuit element 40 is also sealed by the sealing resin body 50. In such a configuration, the rewiring unit 60 described above is provided with signal wirings 66 and 67. One end of the signal wiring 66 is electrically connected to the pad 33 of the power element 30, and the other end is electrically connected to the pad 43 of the circuit element 40. One end of the signal wiring 67 is connected to another pad 43, and the other end forms an external electrode 67e. By providing the rewiring portion 60 on the sealing resin body 50, the connection structure between the power element 30 and the circuit element 40 and the connection structure between the circuit element 40 and the external terminal can be thinned in the Z direction. Thereby, in the configuration including the circuit element 40, the thermal resistance on the surface side of the semiconductor device 10 can be reduced. Therefore, heat dissipation can be improved.

In the present embodiment, the pillar 35 is provided on the source electrode 31 and the pad 33 of the power element 30, and the pillar 45 is provided on the pad 43 of the circuit element 40. The electrodes on the surface of the semiconductor element are connected to the wiring of the rewiring portion 60 via the corresponding pillars 35 and 45. According to this, as described above, it is possible to absorb the thickness variation, the assembly error, and the like. Therefore, the heat dissipation to the surface side can be improved.

In the present embodiment, the lead frame 20 is provided with a protrusion 22 extending from one surface 21a to the rewiring portion 60 side. Further, the rewiring unit 60 is provided with a drain wiring 65. One end of the drain wiring 65 is electrically connected to the tip of the protrusion 22, and the other end is exposed from the opening 61c to form an external electrode 65e. In this way, the external electrode 65e of the drain electrode 32 is provided on the same surface side as the external electrode 64e of the source electrode 31 by utilizing the rewiring portion 60. This makes it possible to facilitate the connection with the outside. Further, the heat transferred to the lead frame 20 can be released to the outside of the drain wiring 65 and further to the outside of the drain wiring 65 via the protrusion 22. Therefore, more heat can be dissipated to the surface side of the semiconductor device 10.

In the present embodiment, the protrusion 22 is provided as a part of the lead frame 20, and the plate thickness T1 of the portion including the protrusion 22 is thicker than the plate thicknesses T2 and T3 of the mounting portion of the semiconductor element. In this way, since the irregularly shaped lead frame 20 is adopted, the number of parts can be reduced and the assembly man-hours can be reduced. Further, since the bonding material is not used, heat dissipation can be improved.

In this embodiment, the power element 30 is thinner than the circuit element 40. Therefore, in the base portion 21 of the lead frame 20, the thickness is different between the mounting portion of the power element 30 and the mounting portion of the circuit element 40. Specifically, a thin-walled portion 210 and a thick-walled portion 211 are provided, a circuit element 40 is arranged in the thin-walled portion 210, and a power element 30 is arranged in the thick-walled portion 211. In this way, since the irregularly shaped lead frame 20 is adopted, the number of parts can be reduced and the assembly man-hours can be reduced. Further, since the bonding material is not used, heat dissipation can be improved.

In the present embodiment, the source wiring 64, which is the main wiring 63, includes a via conductor 64v provided at a position overlapping the source electrode 31 in a plan view. As a result, the heat dissipation path connected to the source electrode 31 can be shortened. That is, the thermal resistance can be reduced. Therefore, the heat dissipation to the surface side of the semiconductor device 10 can be further improved. Similarly, the drain wiring 65, which is the main wiring 63, includes a via conductor 65v provided at a position overlapping the protrusion 22 in a plan view. As a result, the heat dissipation path connected to the protrusion 22 can be shortened. That is, the thermal resistance can be reduced. Therefore, the heat dissipation to the surface side of the semiconductor device 10 can be further improved.

In the present embodiment, the external electrodes 64e and 65e exposed from the openings 61b and 61c are recessed with respect to the surface 61a of the insulator 61. As a result, it is easy to secure the thickness of the bonding material in the configuration in which the bonding material such as solder is arranged on the external electrodes 64e and 65e and connected to the outside. Therefore, the connection reliability can be improved.

Although the lead frame 20 has the protrusion 22 and the rewiring portion 60 has the drain wiring 65, the present invention is not limited to this. The semiconductor device 10 described above may have a configuration in which the protrusion 22 and the drain wiring 65 are excluded. That is, the lead frame 20 having only the base 21 may be used.

The lead frame 20 has shown an example of a variant, but is not limited to this. A flat plate-shaped lead frame 20 may be used. When the circuit element 40 is also provided and the circuit element 40 is thicker than the power element 30, the metal block shown in the embodiment (second embodiment) described later is used as the one surface 21a of the lead frame 20 and the drain electrode 32 of the power element 30. It may be placed between.

Further, although an example including the circuit element 40 as the semiconductor element is shown, the present invention is not limited to this. At least the power element 30 may be included. When only the power element 30 is provided, the rewiring portion 60 may have a signal wiring having one end connected to the pad 33 and the other end forming an external electrode (external terminal).

As the power element 30, an example in which a MOSFET is formed on a semiconductor substrate has been shown, but the present invention is not limited to this. As the switching element, for example, an IGBT may be used. In the case of a configuration without a circuit element 40, that is, a configuration without a pad 33, a diode may be used.

An example in which the insulating layer 24 is provided on the back surface 21b side of the lead frame 20 has been shown, but the present invention is not limited to this. The insulating layer 24 may be eliminated to allow electrical connection of the drain electrode 32 on the back surface side.

An example is shown in which a semiconductor device has pillars 35 and 45 on the electrodes on the surface, but the present invention is not limited to this. The pillars 35 and 45 may be excluded.

An example is shown in which the external electrode 64e includes the corresponding source electrode 31 in a plan view, but the present invention is not limited to this. It is preferable to provide the external electrode 64e so that at least a part thereof overlaps with the corresponding source electrode 31 in a plan view. The wiring distance and heat dissipation distance can be shortened.

(Second Embodiment)
This embodiment is a modification based on the preceding embodiment, and the description of the preceding embodiment can be incorporated. In the prior embodiment, the lead frame 20 (metal member) was used as the wiring member. Other wiring members may be adopted instead of the lead frame 20.

FIG. 5 is a cross-sectional view showing the semiconductor device 10 of the present embodiment and corresponds to FIG. As shown in FIG. 5, the semiconductor device 10 includes a wiring board 120 as a wiring member. The wiring board 120 has a base portion 121 and a protrusion 122 extending from one surface 121a of the base portion 121 to the rewiring portion 60 side as in the previous embodiment. The base portion 121 has a back surface 121b opposite to the front surface 121a.

The base portion 121 is formed by using an insulating base material 1210 made of ceramic, resin, or the like and a metal material such as Cu, and the conductors 1211, 1212 arranged on at least one surface 121a side of the insulating base material 1210. Have. The conductors 1211, 1212 may be referred to as a wiring layer or a wiring pattern. In the present embodiment, the insulating base material 1210 is made of ceramic, and the conductors 1211 and 1212 are arranged only on the side 121a on one side.

The conductor 1211 electrically connects the drain electrode 32 and the drain wiring 65. The conductor 1211 is formed so as to overlap the power element 30 (drain electrode 32) and the drain wiring 65 in a plan view. The conductor 1212 is formed at a position overlapping the circuit element 40 in a plan view. The conductor 1212 is provided to fix (join) the circuit element 40 to the wiring board 120 via the bonding material 44.

The protrusion 122 has a metal block 1220 made of a metal such as Cu, and a bonding material 1221 that connects the metal block 1220 to the conductor 1211. Metal blocks are sometimes referred to as terminals. The tip of the metal block 1220 is substantially flush with the surface 50a of the sealing resin body 50. The drain wiring 65 is connected to the tip of the metal block 1220 exposed from the surface 50a.

The wiring board 120 further has a protrusion 123. Like the protrusion 122, the protrusion 123 has a metal block 1230 and a bonding material 1231 that connects the metal block 1230 to the conductor 1211. The metal block 1230 is interposed between the drain electrode 32 of the power element 30 and the conductor 1211. The drain electrode 32 is connected to the front surface of the metal block 1230 via the bonding material 34, and the conductor 1211 is connected to the back surface via the bonding material 1231. The protrusion 123 functions in the same manner as the thick portion 211 with respect to the thin portion 210 described in the preceding embodiment.

As the bonding materials 1221 and 1231, bonding materials (for example, solder) having excellent conductivity and thermal conductivity can be used as in the bonding material 34. The configuration other than the above is the same as that of the prior embodiment.

<Summary of the second embodiment>
When the wiring board 120 is used as the wiring member as described in the present embodiment, it is possible to obtain an effect equivalent to or similar to the various effects described in the preceding embodiment.

Note that FIG. 5 shows an example in which the wiring board 120 has a protrusion 122 and the rewiring portion 60 has a drain wiring 65, but the present invention is not limited to this. The configuration may be such that the protrusion 122 and the drain wiring 65 are excluded.

An example including a circuit element 40 as a semiconductor element has been shown, but the present invention is not limited to this. At least the power element 30 may be included.

An example is shown in which the wiring board 120 has a protrusion 123, but the present invention is not limited to this. For example, as in the modified example shown in FIG. 6, when the thickness of the circuit element 40 is about the same as the thickness of the power element 30, the protrusion 123 can be excluded. In FIG. 6, the drain electrode 32 is connected to the conductor 1211 via the bonding material 34. Further, the length of the metal block 1220 constituting the protrusion 122 in the Z direction is shorter than that in FIG.

An example is shown in which the conductor 1212 to which the circuit element 40 is fixed is separated from the conductor 1211 to which the power element 30 is fixed, but the present invention is not limited thereto. The conductor 1212 may be eliminated and the circuit element 40 may be fixed to the conductor 1211.

(Third Embodiment)
This embodiment is a modification based on the preceding embodiment, and the description of the preceding embodiment can be incorporated. In the prior embodiment, the wiring member has only one protrusion. A plurality of such protrusions may be provided, and the semiconductor element may be arranged between the protrusions.

FIG. 7 is a cross-sectional view showing the semiconductor device 10 of the present embodiment and corresponds to FIG. As shown in FIG. 7, the semiconductor device 10 has a configuration in which a protrusion 23 and a drain wiring 65 connected to the protrusion 23 are added to the semiconductor device 10 of the first embodiment (see FIG. 2). The protrusion 22 corresponds to the first protrusion, and the protrusion 23 corresponds to the second protrusion.

Like the protrusion 22, the protrusion 23 also extends from one surface 21a of the lead frame 20 toward the rewiring portion 60. The protrusion 23 extends in the Z direction. The tip of the protrusion 23 is exposed from the sealing resin body 50 in a state of being substantially flush with the surface 50a. The protrusion 23 penetrates the sealing resin body 50. The protrusion 23 is provided near the end of the lead frame 20 opposite to the protrusion 22. The protruding portion 23 protrudes from one surface 21a in the thin-walled portion 210. In the X direction, the power element 30 and the circuit element 40 are arranged between the protrusions 22 and 23.

The protrusion 23 is also a columnar body having a substantially rectangular plane. The length of the protrusion 23 in the X direction is shorter than that of the protrusion 22 in the example shown in FIG. Although not shown, the protrusion 23 is also provided so as to straddle (cross) the power element 30 in the Y direction. The length of the protrusion 23 in the Y direction is substantially the same as that of the protrusion 22. The length (thickness) of the protrusion 23 in the Z direction is longer than that of the protrusion 22.

The drain wiring 65 corresponding to the protrusion 23 has the same configuration as the drain wiring 65 corresponding to the protrusion 22. The drain wiring 65 connected to the protrusion 23 also includes the via conductor 65v. One end of the drain wiring 65 is connected to the drain electrode 32 via a lead frame 20 including a protrusion 23, and the other end is exposed from the opening 61c to form an external electrode 65e. As described above, the semiconductor device 10 has two external electrodes 65e electrically connected to the drain electrode 32. The lead frame 20 bridges the rewiring portion 60. In the ZX plane, the lead frame 20 surrounds the semiconductor element.

<Summary of the third embodiment>
According to the semiconductor device 10 of the present embodiment, various effects described in the first embodiment can be obtained. Further, a semiconductor element is arranged between the protrusions 22 and 23 in the X direction, which is the arrangement direction of the protrusions 22 and 23. A metal having a coefficient of linear expansion higher than that of the sealing resin body 50 is arranged not only on the outside of the power element 30 but also on the outside of the circuit element 40 in the X direction. As a result, the balance of the coefficient of linear expansion on both sides (both left and right) is improved in the X direction. Therefore, the warp of the semiconductor device 10 due to thermal stress can be suppressed. By suppressing the warp, the connection reliability can be improved in the connection structure between the semiconductor device 10 and the other member.

The protrusion 23 is not limited to the above configuration. An example of connecting the drain wiring 65 to the protrusion 23 has been shown, but the present invention is not limited to this. As in the modified example shown in FIG. 8, the drain wiring 65 corresponding to the protrusion 23 may be excluded. That is, the protrusion 23 may not be electrically connected to the wiring of the rewiring portion 60.

The length of the protrusion 23 is also not limited to the above example. For example, the length of the protrusion 23 in the X direction may be substantially the same as that of the protrusion 22. The tip of the protrusion 23 may be positioned lower than the tip of the protrusion 22. That is, the protrusion 23 may not penetrate the sealing resin body 50. By providing the protrusion 23, warpage can be suppressed as compared with a configuration without the protrusion 23.

The number of protrusions of the lead frame 20 is not limited to two. For example, two protrusions may be added so as to sandwich the semiconductor element in the Y direction. That is, the lead frame 20 may have four protrusions.

It can also be applied to a configuration in which the circuit element 40 is excluded, that is, a configuration in which only the power element 30 is provided as a semiconductor element. The combination with the semiconductor device 10 described in the second embodiment is also possible. A protrusion on which the semiconductor element is arranged may be added to the wiring board 120 with the protrusion 122.

7 and 8 show an example in which the side surface of the lead frame 20 is exposed from the sealing resin body 50, but the present invention is not limited to this. In at least one of FIGS. 7 and 8, the side surface of the lead frame 20 may be covered with the sealing resin body 50.

(Fourth Embodiment)
This embodiment is a modification based on the preceding embodiment, and the description of the preceding embodiment can be incorporated. In the prior embodiment, the width of the signal wiring was not specifically mentioned. The width of the signal wiring may be partially different.

FIG. 9 is a schematic view of the periphery of the semiconductor element in the semiconductor device 10 of the present embodiment. FIG. 9 shows a simplified electrical connection structure between the power element 30 and the circuit element 40. The rewiring unit 60 has a signal wiring 166 that electrically connects the pads 33 and 43. The signal wiring 166 corresponds to the signal wiring 66 described in the preceding embodiment. The signal wiring 166 has a narrow width portion 166a and a widening portion 166b wider than the narrow width portion 166a. The width is the length in the direction orthogonal to the extension direction in a plan view.

The widening portion 166b is provided in the signal wiring 166 at a portion overlapping the outer peripheral end of the semiconductor element in a plan view and in the vicinity thereof. The signal wiring 166 has two widening portions 166b, a portion overlapping the outer peripheral end of the power element 30 and a portion overlapping the outer peripheral end of the circuit element 40. The narrow width portion 166a is a portion of the signal wiring 166 excluding the widening portion 166b. The narrow portion 166a includes at least a connection portion with the pads 33 and 43 and a vicinity thereof. The signal wiring 166 has a narrow portion 166a between the two widening portions 166b.

<Summary of Fourth Embodiment>
The thermal stress is concentrated on the outer peripheral edge of the semiconductor device. In the present embodiment, in the signal wiring 166, the wiring width of the portion directly above the outer peripheral end, that is, the portion overlapping the outer peripheral end in a plan view is extended with respect to the wiring width of the connecting portion with the pads 33 and 43. As a result, damage to the signal wiring 166 due to the stress concentration described above, for example, breakage or cracking can be suppressed.

As in the signal wiring 266 shown in FIG. 9, the narrow width portion 266a may be provided only at both ends, and the other portions may be the widening portion 266b. The width of the widened portion 266b is wider than that of the narrowed portion 266a. Therefore, the same effect as that of the signal wiring 166 can be obtained.

The above-mentioned signal wiring structure can also be applied to the signal wiring 67 connected to the pad 43. For example, in the signal wiring 67 shown in FIG. 1, the wiring width of the portion overlapping the outer peripheral end of the circuit element 40 may be wider than the wiring width of the connection portion with the pad 43.

The configuration shown in this embodiment can be combined with each of the above-mentioned prior embodiments.

(Fifth Embodiment)
This embodiment is a modification based on the preceding embodiment, and the description of the preceding embodiment can be incorporated. In the prior embodiment, an insulating layer is provided on the back surface of the metal member. Instead of this, the back surface side of the metal member may be sealed.

FIG. 10 is a cross-sectional view showing the semiconductor device 10 of the present embodiment. As shown in FIG. 10, the semiconductor device 10 includes a clip 220 as a wiring member. Like the lead frame 20, the clip 220 is a metal member made of Cu or the like. The clip 220 is formed by bending a metal plate. The semiconductor device 10 includes a power element 30 as a semiconductor element and does not include a circuit element 40.

The clip 220 has a structure similar to that of the lead frame 20 shown in the third embodiment (see FIG. 7), and bridges the rewiring portion 60. The clip 220 is sometimes referred to as a cross-linking member. The clip 220 has a substantially U shape in the ZX plane. The clip 220 has a base portion 221 extending in the X direction and protrusions 222 and 223 extending from one surface 221a of the base portion 221 to the rewiring portion 60 side. The base portion 221 has a back surface 221b opposite to the front surface 221a. The clip 220 of the present embodiment is formed by bending a flat rectangular metal plate having a substantially constant thickness at both ends in the longitudinal direction. The plate thickness direction of the base portion 221 is substantially parallel to the Z direction.

The protrusion 222 is provided at one end of the base 221 and the protrusion 223 is provided at the other end of the base 221. The protrusions 222 and 223 are sometimes referred to as legs and connecting portions. The power element 30 is arranged between the protrusions 222 and 223 in the arrangement direction of the protrusions 222 and 223.

The sealing resin body 50 covers the clip 220 together with the power element 30. The sealing resin body 50 covers not only one side 221a of the clip 220 but also the back side 221b. The sealing resin body 50 has a back surface 50b opposite to the front surface 50a, which is a connection surface with the rewiring portion 60, as an outer surface of the semiconductor device 10. Of the clips 220, only the tips of the protrusions 222 and 223 are exposed from the sealing resin body 50. The tips of the protrusions 222 and 223 are exposed from the sealing resin body 50 in a state of being substantially flush with the surface 50a. In the sealing resin body 50, the thickness of the portion covering the back surface 221b of the clip 220 may be such that electrical insulation can be secured.

The rewiring portion 60 is arranged on the surface 50a of the sealing resin body 50. The rewiring unit 60 has an insulator 61 and wiring arranged on the insulator 61, as in the previous embodiment. The rewiring unit 60 further has a solder ball 68. The insulator 61 includes an insulating layer 62. The wiring includes a source wiring 64 and a drain wiring 65. The source wiring 64 includes a via conductor 64v. One end of the source wiring 64 is connected to a source electrode 31 (not shown) formed on the surface of the power element 30, and a solder ball 68 is connected to the other end. The solder ball 68 forms an external electrode (external terminal) of the source electrode 31.

The drain wiring 65 is connected to the tip of the protrusions 222 and 223. The drain wiring 65 includes a via conductor 65v, respectively. One end of the drain wiring 65 is connected to the tip of the corresponding protrusions 222 and 223, and the solder ball 68 is connected to the other end. The solder ball 68 forms an external electrode (external terminal) of the drain electrode 32.

<Summary of the fifth embodiment>
According to the third embodiment, as in the third embodiment, the clip 220 having a crosslinked structure can improve the balance of the linear expansion coefficients on both sides in the X direction and suppress the warp of the semiconductor device 10 due to thermal stress. In particular, in the example shown in FIG. 10, the clip 220 has a line-symmetrical structure with respect to a virtual line extending in the Z direction through the center of the base portion 221 in the X direction. Therefore, the warp can be effectively suppressed.

Further, the sealing resin body 50 covers the back surface 221b side of the clip 220. Therefore, as compared with the configuration in which the insulating layer 24 or the like is separately provided, the drain electrode 32 can be electrically connected to the external electrode 65e on the front surface side while insulating the back surface 221b side with a simple configuration.

The configuration of the present embodiment can be combined with various configurations shown in the preceding embodiments as long as the wiring member has a crosslinked structure and the sealing resin body 50 covers the back surface of the wiring member. is there. For example, it can be applied to a configuration including a circuit element 40 together with a power element 30.

The shape of the clip 220 is not limited to a substantially U shape. For example, it may be substantially C-shaped or approximately U-shaped.

(Sixth Embodiment)
This embodiment is a modification based on the preceding embodiment, and the description of the preceding embodiment can be incorporated. In the prior embodiment, the semiconductor element is arranged on one surface of the clip, and the back electrode of the power element is electrically connected to the clip. Instead of this, an electronic component may not be arranged on one surface of the clip.

FIG. 11 is a cross-sectional view showing the semiconductor device 10 of the present embodiment. As shown in FIG. 11, the semiconductor device 10 includes a sealing resin body 50 and a rewiring portion 60 arranged on the surface 50a of the sealing resin body 50, as in the previous embodiment. Further, the semiconductor device 10 includes electronic components 70 and 71 and a clip 80. In FIG. 11, the rewiring unit 60 and the electronic components 70 and 71 are shown in a simplified manner.

The rewiring portion 60 is arranged on the surface 50a of the sealing resin body 50. The rewiring unit 60 has a solder ball 68 as in the fifth embodiment. The insulator 61 is formed by laminating a plurality of insulating layers 62 (not shown) as in the previous embodiment. Wiring is arranged in multiple layers in the insulator 61.

The electronic components 70 and 71 are mounted on the connection surface with the sealing resin body 50 in the rewiring portion 60. The electronic components 70 and 71 are sealed by the sealing resin body 50. The electronic components 70 and 71 are electrically connected to the wiring of the rewiring unit 60, and form a circuit together with the wiring. In this embodiment, the electronic component 70 is an IC chip. The electronic component 71 is a passive component such as a capacitor, an inductor, and a resistance element.

The clip 80 has the same structure as the clip 220 shown in the fifth embodiment. The clip 80 is formed by bending a metal plate. The clip 80 has a substantially U shape. The clip 80 has a base portion 81 extending in the X direction and protrusions 82 and 83 provided at both ends of the base portion 81. The plate thickness direction of the base 81 is substantially parallel to the Z direction. The base portion 81 has one surface 81a, which is a surface on the rewiring portion 60 side, and a back surface 81b, which is a surface opposite to the one surface 81a.

The protrusions 82 and 83 extend from one surface 81a of the base 81 to the rewiring portion 60 side. The protrusions 82 and 83 are bent so as to form an angle of, for example, about 90 degrees with respect to the base 81. The protrusions 82 and 83 may be referred to as legs and connecting portions. Electronic components 70 and 71 are arranged between the protrusions 82 and 83 in the arrangement direction (X direction) of the protrusions 82 and 83. The tips of the protrusions 82 and 83 are exposed from the sealing resin body 50 in a state of being substantially flush with the surface 50a. The tips of the protrusions 82 and 83 are connected to the rewiring portion 60, respectively. The clip 80 is sometimes referred to as a cross-linking member.

In the present embodiment, the base 81 is provided so as to overlap all of the electronic components 70 and 71 in a plan view. The back surface 81b of the base 81 is exposed from the sealing resin body 50. The back surface 81b is substantially flush with the back surface 50b of the sealing resin body 50. The clip 80 surrounds the electronic components 70 and 71 with three surfaces of a base 81 arranged in the Z direction with respect to the electronic components 70 and 71 and protrusions 82 and 83 arranged on both sides in the X direction. .. The protrusions 82 and 83 are electrically connected to the wiring 69 of the rewiring unit 60. In this case, the clip 80 functions as a wiring member and constitutes a circuit together with the wiring of the electronic components 70 and 71 and the rewiring unit 60.

<Summary of the sixth embodiment>
In a configuration without a clip (crosslinking member), the number of layers of the rewiring portion and the thickness of the wiring increase in order to cope with an increase in current, that is, the thicker the rewiring portion, the more the balance of the linear expansion coefficient in the Z direction Will get worse. Specifically, in the Z direction, only the sealing resin body is arranged on the back side of the electronic component, whereas the wiring (metal) of the rewiring portion increases on the front side. The coefficient of linear expansion of the sealing resin body is, for example, ^{about 10 × 10-6} / ° C, and the number of linear expansion liquids of the wiring (Cu) constituting the rewiring portion is, for example, ^{about 17 × 10-6} / ° C. .. Therefore, warpage of the semiconductor device due to thermal stress becomes a problem.

On the other hand, in the present embodiment, the clip 80 is provided in the sealing resin body 50 so as to cover the electronic components 70 and 71. In the Z direction, the wiring (for example, Cu) of the rewiring portion 60 is present on one side of the electronic components 70 and 71, and the clip 80 made of metal (for example, Cu) is present on the other side. In this way, the arrangement of the clips 80 improves the balance of the linear expansion coefficients on both sides (upper and lower sides) in the Z direction. Therefore, the warp of the semiconductor device 10 due to thermal stress can be suppressed. By suppressing the warp, the connection reliability can be improved in the connection structure between the semiconductor device 10 and the other member.

Further, according to the present embodiment, as in the third embodiment and the fifth embodiment, the electronic components 70 and 71 are arranged between the protrusions 82 and 83 in the arrangement direction (X direction) of the protrusions 82 and 83. ing. That is, in the X direction, the protrusions 82 and 83 are arranged not only on one side but also on both sides of the electronic components 70 and 71. As a result, the balance of the coefficient of linear expansion on both sides (both left and right sides) is improved even in the X direction. Therefore, the warp of the semiconductor device 10 due to thermal stress can be suppressed. In particular, in the example shown in FIG. 11, the clip 80 has a line-symmetrical structure with respect to a virtual line extending in the Z direction through the center of the base portion 81 in the X direction. Therefore, the warp can be effectively suppressed.

An example is shown in which the back surface 81b of the clip 80 is exposed from the sealing resin body 50, but the present invention is not limited to this. Similar to the fifth embodiment, the sealing resin body 50 may cover the back surface 81b of the clip 80. Only a part of the back surface 81b may be exposed, or the entire surface may be exposed.

An example is shown in which the protrusions 82 and 83 of the clip 80 are electrically connected to the wiring 69 that provides the electrical connection function, but the present invention is not limited thereto. The protrusions 82 and 83 may be connected to a dummy wiring provided separately from the wiring in the rewiring unit 60 and which does not provide a wiring function.

An example is shown in which the electronic component 70 is an IC chip and the electronic component 71 is a passive component, but the present invention is not limited thereto. Further, the shape of the clip 80 may be changed to a substantially C shape or a substantially U shape instead of the substantially U shape.

(7th Embodiment)
This embodiment is a modification based on the preceding embodiment, and the description of the preceding embodiment can be incorporated. In the prior embodiment, an example in which the wiring function is provided only by the clip is shown. Alternatively, electronic components and clips may provide the wiring function.

FIG. 12 is a cross-sectional view showing the semiconductor device 10 of the present embodiment and corresponds to FIG. As shown in FIG. 12, the semiconductor device 10 includes a clip 180. The clip 180 corresponds to the clip 80 described in the sixth embodiment, and has a structure in which the clip 80 is divided into two. The clip 180 has a base 181 and two protrusions 182 and 183. The base portion 181 corresponds to the base portion 81, and the protrusions 182 and 183 correspond to the protrusions 82 and 83. The base portion 181 has a one-sided surface 181a which is a surface on the rewiring portion 60 side and a back surface 181b opposite to the one-sided surface 181a. The clip 180 is divided into two at the base 181. The clip 180 includes two split pieces 180A and 180B.

The split piece 180A has a part of the base portion 181 and a protrusion 182. The split piece 180B has another part of the base portion 181 and a protrusion 183. A gap 184 (gap) is provided between the base portion 181 of the split piece 180A and the base portion 181 of the split piece 180B, and the sealing resin body 50 is arranged in this gap 184. In the present embodiment, in the divided pieces 180A and 180B, the lengths of the bases 181 in the X direction are equal to each other, and the divided pieces 180A and 180B have the same structure as each other. The back surface 181b is substantially flush with the back surface 50b and is exposed from the sealing resin body 50.

The semiconductor device 10 further includes an electronic component 72. In this embodiment, the electronic component 72 is a passive component. The electronic component 72 is arranged on the back surface 181b of the base portion 181 so as to straddle the divided pieces 180A and 180B. The electronic component 72 is arranged outside the sealing resin body 50. The electronic component 72 has two electrodes 72e. The electrode 72e may be referred to as an external electrode or a terminal. In plan view, one of the electrodes 72e overlaps the split piece 180A and the other one of the electrodes 72e overlaps the split piece 180B. Then, the electrode 72e is electrically connected to the corresponding divided pieces 180A and 180B via a joining material (not shown). The electronic component 72 is electrically connected to the rewiring portion 60 via the clip 180. The clip 180 bridges the rewiring portion 60 by connecting the divided pieces 180A and 180B via the electronic component 72. The configuration other than the above is the same as that of the sixth embodiment.

<Summary of the 7th embodiment>
According to this embodiment, a clip 180 including two divided pieces 180A and 180B is used, and the divided pieces 180A and 180B are connected by an electronic component 72. By mounting the electronic component 72 in this way, the clip 180 can be provided with a wiring function.

Further, a part of the electronic parts constituting the circuit is arranged outside the sealing resin body 50 as the electronic parts 72. Thereby, in the semiconductor device 10, it is possible to reduce the thickness of the portion excluding the electronic component 72. When the electronic component 72 is a tall component, the lengths of the protrusions 182 and 183 can be shortened, and the sealing resin body 50 can be thinned. Further, in the case of a component that affects other electronic components, it is possible to suppress malfunction or deterioration of the electronic components 70 and 71.

FIG. 13 shows an example of the cooling structure of the semiconductor device 10 shown in FIG. Here, the heat generating component 72H is used as the electronic component 72. The heat generating component 72H is a component having a large heat generation amount among the electronic components constituting the circuit, for example, an inductor. The electronic device 90 includes a circuit board 91 and a housing 92. The semiconductor device 10 is one of the components mounted on the circuit board 91. The housing 92 has a case 93 and a cover 94. For example, the case 93 has a box shape with one side open. A cover 94 is assembled to the case 93 with the circuit board 91 including the semiconductor device 10 housed in the case 93, and the opening of the case 93 is closed by the cover 94.

Of the housing 92, at least the cover 94 is molded from a metal such as aluminum. The cover 94 has a convex portion 94a at a position where it overlaps with the heat generating component 72H in a plan view. The convex portion 94a projects from the inner surface of the cover 94 toward the heat generating component 72H. A heat conductive member 95 having flexibility such as a heat radiating gel and heat conductive grease is arranged between the tip surface of the convex portion 94a and the heat generating component 72H. The heat conductive member 95 is pushed by the convex portion 94a as the cover 94 is assembled, and is in close contact with the convex portion 94a and the heat generating component 72H.

According to the electronic device 90, since the heat generating component 72H is arranged outside the sealing resin body 50, the influence of heat on other electronic components 71 and 72 such as the IC chip can be reduced. Further, the heat generated by the heat generating component 72H can be released to the cover 94 (housing 92) via the heat conductive member 95. Therefore, the influence of heat on other electronic components 71 and 72 can be further reduced. Further, in the Z direction, a heat dissipation path to the circuit board 91 via the rewiring portion 60 and a heat dissipation path to the cover 94 via the heat conductive member 95 are formed. The heat of the semiconductor device 10 can be released separately in the upper and lower parts in the Z direction. Therefore, the heat dissipation of the semiconductor device 10 can be improved.

In the housing 92, a member having a convex portion facing the heat generating component 72H may be used as a case, and a member on the opposite side may be used as a cover. In this case, at least the case may be made of metal. For example, when the circuit board is housed in the case and fixed to the case by screwing or the like, the heat conductive member comes into close contact with the convex portion and the heat generating component 72H.

The cooling structure is not limited to the above examples. For example, the heat of the heat generating component 72H may be dissipated to the housing of another electronic device via the heat conductive member.

(8th Embodiment)
This embodiment is a modification based on the preceding embodiment, and the description of the preceding embodiment can be incorporated. In this embodiment, a modified example of a clip having a divided structure is shown.

In the case of the semiconductor device 10 including the clip 180 having a divided structure, in order to mount the electronic component 72 after molding the sealing resin body 50, it is necessary to expose at least the connecting portion of the electronic component 72 on the back surface 181b from the sealing resin body 50. There is.

As shown in FIG. 14A, the sealing resin body 50 is molded with the molding die 96 pressed against the back surface 181b. As a result, as shown in FIG. 14B, the back surface 181b of the clip 180 can be exposed from the back surface 50b of the sealing resin body 50.

However, in order to make the sealing resin body 50 and the semiconductor device 10 have a predetermined thickness, the molding die 96 is molded under the condition of being pushed in excessively in consideration of the dimensional tolerance and the assembly tolerance. Therefore, depending on the tolerance, the force received by the clip 180 from the molding die 96 may increase, and the reliability of the connection portion between the clip 180 and the rewiring portion 60 (wiring 69) may decrease.

Therefore, in the present embodiment, as shown in FIG. 15, spring portions 185 are provided on the protrusions 182 and 183, respectively. The spring portion 185 is partially provided at the protrusions 182 and 183 extending in the Z direction. The spring portion 185 is configured to be able to bend in the Z direction. The spring portion 185 includes a portion whose plate thickness direction is inclined with respect to the X direction. For example, a portion substantially parallel to the Z direction may be included.

In FIGS. 14 and 15, for convenience, the electronic components 70 and 71 are omitted, and the rewiring portion 60 is shown in a simplified manner.

<Summary of the eighth embodiment>
According to this embodiment, the clip 180 is provided with a spring portion 185. As a result, when the sealing resin body 50 is molded, even if the clip 180 is pressed to expose the back surface 181b, the spring portion 185 is deformed and the stress can be relaxed. Therefore, the reliability of the connection portion between the clip 180 and the rewiring portion 60 can be ensured while exposing the back surface 181b from the sealing resin body 50.

14 and 15 show an example in which the tips of the protrusions 182 and 183 are bent outward in the X direction, and the bent portion is a connection portion with the wiring 69. Such a shape of the clip 180 may be applied to a prior embodiment (for example, FIG. 13). Further, the spring portion 185 described in the present embodiment may be applied to the preceding embodiment.

(Other embodiments)
Disclosure in this specification, drawings and the like is not limited to the illustrated embodiments. The disclosure includes exemplary embodiments and modifications by those skilled in the art based on them. For example, disclosure is not limited to the parts and / or element combinations shown in the embodiments. Disclosure can be carried out in various combinations. The disclosure can have additional parts that can be added to the embodiment. Disclosures include those in which the parts and / or elements of the embodiment have been omitted. Disclosures include the replacement or combination of parts and / or elements between one embodiment and another. The technical scope disclosed is not limited to the description of the embodiments. Some technical scopes disclosed are indicated by the claims description and should be understood to include all modifications within the meaning and scope equivalent to the claims statement.

Disclosure in the description, drawings, etc. is not limited by the description of the scope of claims. The disclosure in the description, drawings, etc. includes the technical ideas described in the claims, and further covers a wider variety of technical ideas than the technical ideas described in the claims. Therefore, various technical ideas can be extracted from the disclosure of the description, drawings, etc. without being bound by the description of the claims.

10 ... Semiconductor device, 20 ... Lead frame, 21 ... Base, 21a ... One side, 21b ... Back side, 210 ... Thin wall part, 211 ... Thick part, 22, 23 ... Protrusions, 24 ... Insulation layer, 120 ... Wiring board, 121 ... Base, 121a ... One side, 121b ... Back side, 1210 ... Insulating base material, 1211, 1212 ... Conductor, 122, 123 ... Protrusions, 1220, 1230 ... Metal block, 1222, 1231 ... Bonding material, 220 ... Clip, 221 ... Base, 221a ... One side, 221b ... Back side, 222, 223 ... Projection, 30 ... Power element, 31 ... Source electrode, 32 ... Drain electrode, 33 ... Pad, 34 ... Bonding material, 35 ... Pillar, 40 ... Circuit element , 43 ... Pad, 44 ... Bonding material, 45 ... Pillar, 50 ... Encapsulating resin body, 50a ... Front surface, 50b ... Back surface, 60 ... Rewiring part, 61 ... Insulator, 61a ... Front surface, 61b, 61c, 61d ... Opening, 62 ... Insulation layer, 63 ... Main wiring, 64 ... Source wiring, 64e ... External electrode, 64v ... Via conductor, 65 ... Drain wiring, 65e ... External electrode, 65v ... Via conductor, 66, 67, 166, 266 ... Signal wiring, 166a, 266a ... Narrow width portion, 166b, 266b ... Widening portion, 66v, 67v ... Via conductor, 67e ... External electrode, 68 ... Solder ball, 69 ... Wiring, 70, 71, 72 ... Electronic component, 72e ... Electrode, 72H ... Heat generating component, 80, 180 ... Clip, 180a, 180b ... Divided piece, 81, 181 ... Base, 81a, 181a ... One side, 81b, 181b ... Back side, 82, 83, 182, 183 ... Projection, 184 ... Gap, 185 ... Spring, 90 ... Electronic device, 91 ... Circuit board, 92 ... Housing, 93 ... Case, 94 ... Cover, 94a ... Convex, 95 ... Heat conductive member, 96 ... Mold

Claims (11)

Wiring members (20, 120, 220) having one surface (21a, 121a, 221a) and
A semiconductor element arranged on the one surface, the back surface electrode (32) formed on the one surface side as a main electrode and electrically connected to the wiring member, and a surface opposite to the back surface electrode. A power element (30) having a surface electrode (31) formed on the
A sealing resin body (50) arranged on the one surface of the wiring member and sealing the power element together with the one surface.
An insulator (61) laminated on a surface of the sealing resin body opposite to the surface opposite to the one surface, and wiring provided on the insulator, which is electrically connected to the main electrode. A rewiring portion (60) having a main wiring (63) partially exposed from an opening (61b) provided in the insulator to form an external electrode.
With
The main wiring is a semiconductor device including a surface electrode wiring (64) electrically connected to the surface electrode. As the semiconductor element, a circuit element (40) in which a drive circuit for the power element is formed and sealed together with the power element is included.
The power element and the circuit element each have pads (33, 43) which are signal electrodes on the surface on the surface electrode side.
The semiconductor device according to claim 1, wherein the rewiring unit includes signal wiring (66, 67) connected to the pad as the wiring. The semiconductor device according to claim 2, wherein the signal wiring has a width of a portion overlapping the outer peripheral end of the semiconductor element wider than a width of a connecting portion with the pad in a plan view in a plate thickness direction of the semiconductor element. The semiconductor element is a metal columnar body (35, 45) formed on the surface on the rewiring portion side, one end of which is exposed from the sealing resin body, and electrically connects the semiconductor element and the corresponding wiring. The semiconductor device according to any one of claims 1 to 3. The wiring member has protrusions (22, 122, 222) extending from the one surface to the rewiring portion side.
The semiconductor device according to any one of claims 1 to 4, wherein the main wiring includes a back surface electrode wiring (65) electrically connected to the back surface electrode via the protrusion. The wiring member is a metal member having a deformed strip, and is
The semiconductor device according to claim 5, wherein the portion of the metal member including the protrusion is thicker than the mounting portion of the semiconductor element. The wiring member is a metal member having a deformed strip, and is
The metal member has a second protrusion (23, 223) extending from one surface toward the rewiring portion, in addition to the first protrusion which is the protrusion.
The semiconductor device according to claim 5 or 6, wherein the semiconductor element is arranged between the first protrusion and the second protrusion in the arrangement direction of the first protrusion and the second protrusion. .. The power element is thinner than the circuit element,
The wiring member is a metal member having a deformed strip, and is
The semiconductor device according to claim 2 or 3, wherein in the metal member, the mounting portion of the power element is thicker than the mounting portion of the circuit element. The wiring member is any one of claims 1 to 5, which is a wiring substrate having an insulating base material (1210) and a conductor (1211) arranged on at least the surface of the insulating base material on the semiconductor element side. The semiconductor device described in 1. The invention according to any one of claims 1 to 9, wherein the main wiring includes a conductor (64v) in a through hole provided at a position overlapping the corresponding main electrode in a plan view in a plate thickness direction of the semiconductor element. Semiconductor device. The semiconductor device according to any one of claims 1 to 10, wherein the external electrode is recessed with respect to the surface of the insulator.

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