JP2003243580A - Semiconductor device and manufacturing method therefor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a semiconductor device having a heat sink and a manufacturing method therefor. <P>SOLUTION: A semiconductor device 10 is configured by manufacturing a heat sink 14 and an extraction electrode 13 from one sheet metal 20. The heat sink 14 and the extraction electrode 13 are formed by bending the sheet metal 20. A semiconductor element 15 is fixed on the upper part of the heat sink 14. The electrode of the semiconductor element 15 and the extraction electrode 13 are electrically connected by using a metal thin wire 12. The entire of the device is sealed with an insulated resin 11. By removing the sheet metal 20 exposed on the rear surface of the insulated resin 11, the heat sink 14 and the extraction electrode 13 are electrically separated. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor device and a manufacturing method thereof, and more particularly to a semiconductor device in which a heat sink and a take-out electrode are formed from a single bent metal plate and a manufacturing method thereof.

[0002]

2. Description of the Related Art Conventionally, in a semiconductor device set in an electronic device, a conductive pattern is formed on, for example, a printed circuit board, a ceramic substrate or a metal substrate, and an LS is formed on the conductive pattern.
An active element such as I or discrete TR, and a passive element such as a chip capacitor, a chip resistor or a coil are mounted and configured. Then, the conductive pattern and the element are electrically connected to realize a circuit having a predetermined function.

In FIG. 7, the outermost rectangular line is
At least the surface of the mounting substrate 31 is insulated.
Then, a conductive pattern 2 made of Cu is stuck on this. The conductive pattern 32 is composed of an external extraction electrode 32A, a wiring 32B, a die pad 32C, a bonding pad 32D, an electrode 34 for fixing the passive element 33, and the like.

The die pad 32C is in the form of a bare chip such as a TR, a diode, a composite element or an LSI and is fixed thereto via solder. The electrodes on the fixed chip are electrically connected to the bonding pads 32D via thin metal wires 35A, 35B and 35C for bonding wires. This thin metal wire is generally classified into a small signal and a large signal, and the small signal portion is 30 to 80 μm.
A fine metal wire of φ is used. And here, about 40 μm
An Al wire 5A or Au wire made of φ is adopted. Further, an Al wire of about 100 to 500 μmφ is adopted for the large signal portion. Especially for large signals, because the wire diameter is large,
The μmφ Al wire 5B and the 300 μmφ Al wire 53C are selected. The diameter of the thin metal wire for a large signal is appropriately selected in consideration of the flowing current capacity and the bonding pad size.

The power TR6 for passing a large current is fixed to the heat sink 37 on the die pad 32C in order to prevent the temperature of the chip from rising.

Then, the electrode 32A for external extraction, the die pad 32C, the bonding pad 32D, and the electrode 34.
The wiring 32B is extended to various places to form a circuit.
Further, when the wirings intersect with each other due to the position of the chip and the way of extending the wirings, the jumping wires 38A, 38
B is adopted.

[0007]

The circuit device as described above has the following problems.

First, when a power transistor is fixed to a substrate in which a conductive path is incorporated, a heat sink is fixed first, the power transistor is fixed on the heat sink, and then the bonding pad portion of the power transistor and the conductive path are fixed. And were electrically connected to each other using a thick metal wire for the power transistor. Therefore, the cost is increased and the working time is lengthened due to the extremely long assembly process. Further, when connecting the bonding pad portion of the power transistor and the conductive path with the metal thin wire, there is a problem that the metal thin wire is cut or short-circuited due to contact with the heat sink.

Secondly, in the case of a metal thin wire that electrically connects a semiconductor element such as a transistor, when the metal thin wire is exposed, an epoxy coating, a case or the like is used to protect the exposed metal thin wire. There was a problem that required work.

Third, when a package in which a semiconductor element is fixed to a lead frame currently on the market is mounted on a substrate,
Since this package size is very large, there is also a problem that the size of the substrate becomes large.

Fourthly, the heat sink on which the semiconductor device is mounted is manufactured by punching a metal plate having a predetermined thickness with a die. Therefore, it is necessary to separately prepare a metal plate having a different thickness and a die for punching the metal plate depending on the shape of the heat sink required. This has led to higher costs.

The present invention has been made in view of the above problems. Therefore, an object of the present invention is to provide a semiconductor device having a heat sink and a manufacturing method thereof.

[0013]

The semiconductor device of the present invention comprises:
First, a heat sink made of a bent metal plate, a take-out electrode formed of the metal plate and arranged in the vicinity of the heat sink, a semiconductor element fixed on the heat sink, and an electrode of the semiconductor element. And a connection means for electrically connecting the extraction electrode with the extraction electrode, and an insulating resin for burying the heat sink, the extraction electrode and the thin metal wire and integrally supporting the whole.

Secondly, the semiconductor device of the present invention is characterized in that the upper surface of the heat sink and the upper surface of the extraction electrode have substantially the same height. OLE_LINK1 The semiconductor device of the present invention is OLE_LINK1 Thirdly, the semiconductor element is
It is a power semiconductor device.

Fourthly, the semiconductor device of the present invention is characterized in that the connecting means is a thin metal wire.

A method of manufacturing a semiconductor device according to the present invention is a first method.
A step of preparing a metal plate, a step of forming a heat sink and a take-out electrode by bending the metal plate, a step of fixing a semiconductor element on the heat sink, an electrode of the semiconductor element, and a take-out step. Electrically connecting the electrodes with a connecting means, sealing the heat sink, the take-out electrode, the semiconductor element and the connecting means with an insulating resin, and electrically connecting the heat sink and the take-out electrode. And a step of physically separating.

The method of manufacturing a semiconductor device according to the present invention is the second method.
In addition, the connecting means is a thin metal wire.

The method of manufacturing a semiconductor device according to the present invention is a third method.
In addition, the heat sink and the extraction electrode are entirely plated.

The method of manufacturing a semiconductor device according to the present invention is the fourth method.
In addition, the thickness of the heat sink is controlled by the number of times the metal plate is bent.

[0020]

BEST MODE FOR CARRYING OUT THE INVENTION (First Description of Semiconductor Device 10)
Embodiment) With reference to FIG. 1, the structure of a semiconductor device 10 according to the present invention will be described. The semiconductor device 10 has the following configuration. That is, the heat sink 14 formed of a bent metal plate, the extraction electrode 13 formed of the metal plate and disposed in the vicinity of the heat sink 14, the semiconductor element 15 fixed on the heat sink, and the semiconductor element 15 The semiconductor device 10 is composed of the thin metal wire 12 that electrically connects the electrode and the lead-out electrode 13, and the insulating resin 11 that burys the heat sink, the lead-out electrode 13 and the thin metal wire 12, and integrally supports the whole. There is. Each of these components will be described below.

The heat sink 14 is formed by bending a single metal plate, and has a function of releasing heat generated from the semiconductor element 15 fixed to the upper part to the outside. Therefore, by changing the bending position and the number of times of bending the metal plate, the heat sink 1
The cross-sectional area and thickness of 4 can be varied. Further, it is also electrically joined to the electrode on the back surface of the semiconductor element 15, and also functions as an electrode. As the material of the metal plate, a metal material having excellent heat dissipation, workability, and low electric resistance can be used. In addition, the heat sink 14
The surface of the may be plated to improve the electrical conductivity of the current. The material used for plating is N
i or Au can be used. Here, in consideration of the cost of materials, plating with Ni is preferable. When Al wire is used as the thin metal wire,
By plating with Ni, the bondability of the Al wire can be improved. As the metal plate used as a material, any metal material can be generally used as long as it is a material having both thermal conductivity and cost performance. For example, copper has both thermal conductivity and cost performance, and is preferable as a material for the metal plate.

The extraction electrode 13 is made of the same material as the heat sink 14, and is formed by bending a metal plate. Therefore, the height of the material of the extraction electrode can be freely adjusted. The semiconductor element 15 fixed on the heat sink 14 is electrically connected to the semiconductor element 15 through a thin metal wire and serves as an electrode of the semiconductor device 10.
Here, the height of the take-out electrode 13 is equal to that of the heat sink 1.
It is adjusted to be almost the same as the height of 4. As a result, the thin metal wire 12 can be used as a connecting means between the semiconductor element 15 and the extraction electrode 13.

As the semiconductor element 15, a power semiconductor element or the like which has a large heat generation amount can be adopted. The semiconductor element 15 has two electrodes on the upper surface, and the two extraction electrodes 1 are provided via the thin metal wire 12.
3 is electrically connected. However, it is not particularly limited to the power transistor. For example, in a power semiconductor device, a power MOSFET, an IGBT, a SIT, a large current driving Tr, a large current driving IC (MOS type BIP).
Type Bi-CMOS type) memory device or the like can be used. Here, when a power IC having a large number of electrodes is adopted, the number of extraction electrodes 13 can be changed according to the number of electrodes.

As the thin metal wire 12, 20 to 80 μmφ
It is possible to adopt the thin metal wire. Conventionally, when such a thin metal wire having a small diameter is used for the semiconductor element 15 fixed onto the heat sink 14, a short circuit between the metal wire 12 and the shoulder portion of the heat sink 14 has been a problem. Therefore, in order to avoid this problem, a thick line of about 120 to 500 μmφ has been conventionally used.
In the present invention, the heat sink 1 to which the circuit element 15 is fixed
4 and the take-out electrode 13, which serves as a bonding pad for the metal thin wire, have almost the same height, and thus the metal thin wire 12 as described above can be adopted. Therefore, it is possible to mount the power IC having a very narrow electrode gap on the heat sink 14 and provide the take-out electrode 13 around the heat sink 14 to connect the electrode of the power IC and the take-out electrode 13 with a thin metal wire.

The insulating resin 11 has a function of sealing the above-mentioned respective elements and integrally supporting the semiconductor device 10.
Here, as the insulating resin 11, a thermosetting resin such as an epoxy resin, a thermoplastic resin such as a polyimide resin or polyphenylene sulfide can be used. Further, as the insulating resin 11, any resin can be adopted as long as it is a resin that is hardened using a mold or a resin that can be coated and coated.

With the structure of the semiconductor device 10 as described above, the following effects can be obtained.

First, the heat sink 14 to which the semiconductor element 15 is fixed and the extraction electrode 13 have substantially the same height. Therefore, the metal thin wire 12 can be adopted as a connecting means for electrically connecting the electrode of the semiconductor element 15 and the extraction electrode 13. As a result, the distance between the heat sink 14 and the take-out electrode 13 can be reduced, and the size of the entire semiconductor device 10 can be reduced. Furthermore, the size of the hybrid integrated circuit device or the like in which the semiconductor device 10 is mounted can be reduced.

Secondly, in the semiconductor device 10, the heat sink 14, the extraction electrode 13, the semiconductor element 15 and the thin metal wire 12 are integrally sealed with the insulating resin 11. Therefore, when the semiconductor device 10 is mounted on a hybrid integrated circuit or the like, in the process of assembling the hybrid integrated circuit, the process of fixing the semiconductor element 15 and the process of wire-bonding the metal fine wires 12 can be omitted. Second Embodiment Explaining Method of Manufacturing Semiconductor Device 10 A method of manufacturing the semiconductor device 10 will be described with reference to FIGS. In this embodiment, the semiconductor device 10 is manufactured by the following steps. That is, a step of preparing the metal plate 20, a step of forming the heat sink 14 and the extraction electrode 13 by bending the metal plate 20, a step of fixing the semiconductor element 15 on the heat sink 14, and an electrode of the semiconductor element 15. Extraction electrode 12
And a step of electrically connecting the metal thin wire 12 with the metal thin wire 12, and a step of sealing the heat sink 14, the extraction electrode 13, the semiconductor element 15, and the metal thin wire 12 with the insulating resin 11.
The semiconductor device 10 is manufactured by a process of electrically separating the heat sink 14 and the take-out electrode 13. Each of these steps will be described below.

First Step: See FIG. 2 This step is a step of preparing a metal plate 20 which is a material for the heat sink and the take-out electrode. The metal plate 20 has a rectangular portion that becomes the heat sink 14 when bent, and a portion that extends from the rectangular portion and becomes the extraction electrode when bent. As the material of the metal plate 20, as long as it is a material having both thermal conductivity and cost performance, a metal material can be generally adopted. For example, copper has both thermal conductivity and cost performance, and is preferable as a material for the metal plate 20.

Second Step: See FIGS. 2 and 3 In this step, the heat sink 14 and the take-out electrode 13 are formed by bending the metal plate 20. Referring to FIG. 2, a bending line 21A of the metal plate 20
Then, the heat sink 14 is formed by bending the metal plate 20 by 180 degrees. Further, the extraction electrode 13 is formed by bending the metal plate 20 by 90 degrees along the bending line 21B.

Referring to FIG. 3, heat sink 14 and extraction electrode 13 are formed by bending metal plate 20 in this manner. The heat sink 14 changes the number of times and the position at which the metal plate 20 is bent,
Its size and thickness can be controlled. Further, the size and thickness of the extraction electrode 13 can also be controlled by changing the number of times and the position at which the metal plate 20 is bent. Here, since the extraction electrode 13 is manufactured by bending the metal plate 20 by 90 degrees, it has a hollow structure.

Further, the heat sink 14 and the take-out electrode 13 may be plated on their surfaces, if necessary.

Third Step: See FIG. 4 In this step, the semiconductor element 15 is fixed on the heat sink 14 and the electrode of the semiconductor element 15 and the take-out electrode 13 are electrically connected.

The semiconductor element 15 is fixed to the heat sink 14 with solder paste or the like. As the semiconductor element 15, for example, a power transistor can be used. Therefore, the heat generated from the power transistor is dissipated to the outside through the heat sink 14.

The two electrodes provided on the upper surface of the semiconductor element 15 are connected to the extraction electrode 13 via the metal thin wire 12, respectively. Here, the heat sink 14 to which the semiconductor element 15 is fixed and the extraction electrode 13 have substantially the same height. Therefore, there is no possibility that the shoulder portion of the heat sink 14 and the thin metal wire 12 come into contact with each other to cause a short circuit. From this, it is possible to use a metal thin wire having a diameter of 20 to 80 μm.

The semiconductor element 15 need not be limited to the power transistor. For example, in a power semiconductor element, a power MOSFET, an IGBT, a SIT, a large current driving Tr, a large current driving IC (MOS type BIP type Bi
A (CMOS type) memory device or the like can be used.

Fourth Step: See FIG. 5 This step is a step of sealing the heat sink 14, the take-out electrode 13, the semiconductor element 15 and the thin metal wire 12 with the insulating resin 11.

The insulating resin 11 has a function of integrally supporting the entire semiconductor device 10. Here, the insulating resin 11
As the material, a thermosetting resin such as an epoxy resin, a thermoplastic resin such as a polyimide resin or polyphenylene sulfide can be used. If the insulating resin 11 is a resin that is hardened using a mold or a resin that can be applied and covered,
All resins can be used.

The thickness of the insulating resin 11 is adjusted so that the top of the thin metal wire 12 is sufficiently covered. However, the thickness of the insulating resin 11 can be changed in consideration of the rigidity and heat dissipation of the semiconductor device 10.

The portion of the metal plate 20 that connects the heat sink 14 and the take-out electrode 13 is separated in the next step. Therefore, the portion of the metal plate 20 that connects the heat sink 14 and the extraction electrode 13 may be exposed from the back surface of the insulating resin 11.

Fifth Step: See FIG. 6 This step is a step of removing the metal plate 20 in the portion connecting the heat sink 14 and the extraction electrode 13. That is, this step is a step of electrically separating the heat sink 14 and the extraction electrode 13.

Specifically, the heat sink 1 is removed by removing the metal plate 20 at the portion shown by the dotted line in FIG.
4 and the take-out electrode 13 can be electrically separated. This step can be performed by polishing, grinding, etching, metal evaporation of laser, or the like. In an example of the embodiment of the present invention, as shown in FIG. 6, the dotted line portion is cut by bottom surface cutting.

In the step of removing the other metal plate 20, the back surface of the metal plate 20 is partially cut by cutting the bottom surface, and then the bottom surface of the insulating resin 11 is etched to flatten the back surface of the metal plate 20. There is a process, a process of removing the back surface of the metal plate 20 by etching until the vicinity of the lower surface of the insulating resin 11 is exposed, and the like.

Here, for example, when the insulating resin 11 is cut by the bottom surface cutting until it is exposed, the scraps of the metal plate 20 and the burr-shaped metal thinly spread to the outside bite into the insulating resin 11. There is. Therefore, by using the step of separating by etching from the middle of the removal of the metal plate 20, the insulating resin 11 can be more surely provided on the insulating resin 11 by removing scraps of the metal plate 20 or burrs that are thinly spread to the outside. The metal is formed without biting. As a result, it is possible to prevent a short circuit between the conductive patterns having minute intervals.

Further, a conductive material such as solder is applied to the exposed back surfaces of the heat sink 14 and the take-out electrode 13 if necessary. Through the above steps, the semiconductor device 10 as shown in FIG. 1 is manufactured.

With the method of manufacturing the semiconductor device 10 as described above, the following effects can be obtained.

First, the heat sink 14 and the take-out electrode 13 are formed by bending the metal plate 20. Therefore, the size of the heat sink 14 and the extraction electrode 13 can be changed by changing the position where the metal plate 20 is bent and the number of times the metal plate 20 is bent.

Secondly, conventionally, the heat sink 14 is formed by punching a metal plate with a die. Therefore,
In order to change the size of the heat sink 14, it is necessary to newly prepare a metal plate and a mold. On the other hand, since the heat sink 14 of the present invention is formed by bending the metal plate 20, the heat sink 14 can be easily formed.
The size of can be changed.

[0049]

According to the present invention, the following effects can be obtained.

First, the heat sink 14 to which the semiconductor element 15 is fixed and the take-out electrode 13 have substantially the same height. Therefore, the metal thin wire 12 can be adopted as a connecting means for electrically connecting the electrode of the semiconductor element 15 and the extraction electrode 13. As a result, the distance between the heat sink 14 and the take-out electrode 13 can be reduced, and the size of the entire semiconductor device 10 can be reduced.

Secondly, in the semiconductor device 10, the heat sink 14, the take-out electrode 13, the semiconductor element 15 and the thin metal wire 12 are integrally sealed with the insulating resin 11. Therefore, when the semiconductor device 10 is mounted on a hybrid integrated circuit or the like, in the process of assembling the hybrid integrated circuit, the process of fixing the semiconductor element 15 and the process of wire-bonding the metal fine wires 12 can be omitted.

Thirdly, the heat sink 14 and the extraction electrode 13 are formed by bending the metal plate 20. Therefore, the size of the heat sink 14 and the extraction electrode 13 can be changed by changing the position where the metal plate 20 is bent and the number of times the metal plate 20 is bent.

Fourthly, conventionally, the heat sink 14 is formed by punching a metal plate with a die. Therefore,
In order to change the size of the heat sink 14, it is necessary to newly prepare a metal plate and a mold. On the other hand, since the heat sink 14 of the present invention is formed by bending the metal plate 20, the heat sink 14 can be easily formed.
The size of can be changed.

[Brief description of drawings]

FIG. 1 is a perspective view of a semiconductor device of the present invention.

FIG. 2 is a plan view illustrating the method for manufacturing the semiconductor device of the present invention.

FIG. 3 is a perspective view illustrating a method for manufacturing a semiconductor device of the present invention.

FIG. 4 is a perspective view illustrating a method for manufacturing a semiconductor device according to the present invention.

FIG. 5 is a perspective view illustrating a method for manufacturing a semiconductor device according to the present invention.

FIG. 6 is a cross-sectional view illustrating the method for manufacturing the semiconductor device of the present invention.

FIG. 7 is a plan view illustrating a conventional circuit device.

Claims (8)

[Claims] 1. A heat sink made of a bent metal plate, a take-out electrode formed of the metal plate and arranged in proximity to the heat sink, a semiconductor element fixed on the heat sink, and a semiconductor element of the semiconductor element. A semiconductor device comprising: a connecting means for electrically connecting an electrode and the lead-out electrode; and an insulating resin for burying the heat sink, the lead-out electrode and the connecting means and integrally supporting the whole. 2. The semiconductor device according to claim 1, wherein an upper surface of the heat sink and an upper surface of the extraction electrode have substantially the same height. 3. The semiconductor device according to claim 1, wherein the semiconductor element is a power semiconductor device. 4. The semiconductor device according to claim 1, wherein the connecting means is a thin metal wire. 5. A step of preparing a metal plate, a step of forming a heat sink and an extraction electrode by bending the metal plate, a step of fixing a semiconductor element on the heat sink, and an electrode included in the semiconductor element. , A step of electrically connecting the extraction electrode with a connecting means, a step of sealing the heat sink, the extraction electrode, the semiconductor element and the connection means with an insulating resin, the heat sink and the extraction electrode And a step of electrically separating the semiconductor device and the semiconductor device. 6. The method of manufacturing a semiconductor device according to claim 5, wherein the connecting means is a thin metal wire. 7. The method of manufacturing a semiconductor device according to claim 5, wherein the heat sink and the extraction electrode are entirely plated. 8. The method of manufacturing a semiconductor device according to claim 5, wherein the thickness of the heat sink is controlled by the number of times the metal plate is bent.