JPH09252075A - Semiconductor device and manufacture thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To eliminated the vertical movements of a support plate at the time of molding a semiconductor chip fixed to the plate, by casting resin in the cavity of a transfer mold to form a sealer in the state that the plate of a lead frame is supported in a predetermined height by a magnetic force at the time of transfer molding. SOLUTION: After an assembled lead frame 15 is mold clamped in the mold 30 of a transfer molding machine, electromagnets 41, 41 contained in lower and upper molds 31, 32 are magnetized by a controller 45 to predetermined magnetic force. As a result, the upper and lower surfaces of a permanent magnet 11 fixed to a support plate 4 are repelled to the upper surface of the electromagnet 41 of the mold 31 and the lower surface of the electromagnet 42 of the mold 32. Accordingly, the plate 4 is extended parallel to the bottom 46 and the ceiling 47 of the cavity, and supported by the magnetic forces of the electromagnets 41, 42. Melted resin 50 is cast in the cavity 35 from the gate 34 in this state to cover the material to be sealed such as the plate 4, a semiconductor chip 6 and the like with sealant.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor device (hybrid integrated circuit device) and a method for manufacturing the same, and particularly to a wire, a support plate and a wiring on the front surface (main surface and back surface) of a sealing body in a resin-sealed semiconductor device. The present invention relates to a technique effectively applied to a transfer molding technique that does not expose a portion of an object to be sealed such as a substrate.

[0002]

2. Description of the Related Art In semiconductor devices such as ICs (integrated circuit devices), a resin (resin) sealing structure is known as a package structure for covering semiconductor chips and the like.

The resin-sealed semiconductor device is manufactured using a lead frame. The lead frame is formed by patterning a thin metal plate by etching or precision press. Explaining an example of the lead frame, the lead frame includes a rectangular frame body, a support plate positioned in the center of the frame body, and supported by two or four support leads extending from the frame body, It is composed of a plurality of leads extending from the frame body and having their tips close to the periphery of the support plate, and a dam for connecting the leads and the frame body and for preventing the melted resin from flowing out at the time of transfer molding.

In manufacturing a resin-sealed semiconductor device,
First, the semiconductor chip is fixed to the main surface of the support plate. After that, the electrodes of the semiconductor chip and the tips of the leads are connected by a conductive wire. Next, after the lead frame is clamped in the mold of the transfer molding apparatus, the melted resin is injected into the cavity of the mold to cover the semiconductor chip, wires, etc. with the sealing body (package). After the transfer molding, unnecessary lead frame portions are cut and removed, and the leads protruding from the package are molded into a desired shape to manufacture a desired semiconductor device.

Semiconductor devices have been made thinner by making the package thinner. TQFP (Thin Quad) with resin package thickness as thin as 1mm
FlatPackage) is described in, for example, “Nikkei Microdevice”, September 1988 issue, published by Nikkei BP, September 115, pp. 115-P121. In this document, the die pad is displaced by the difference in the resin flow on the chip and under the die pad, and the wire height is 200 μm.
It describes that it is suppressed to m or less, and measures against short circuit due to wire deformation during molding.

On the other hand, as described in P13 and P14, "Latest Hybrid Mounting Technology" issued by the Industrial Research Institute, May 13, 1988, a transfer mold type in which a lead frame is used and sealing is performed by transfer molding. A hybrid IC (hybrid integrated circuit device) is known.

Further, in Japanese Patent Application No. 6-273202, at the time of transfer molding, a support plate is clamped by a protrusion provided on the upper and lower molds (clamp) so that the support plate does not move up and down by an inflowing resin. The manufacturing technique of the hybrid integrated circuit device in which the wire is not exposed on the surface of the package is described. In addition, in this technology, the support plate has a frame shape, and the heat dissipation plate is fixed to the back surface (lower surface) of the support plate, and the bottom surface of the heat dissipation plate is closely adhered to the bottom surface of the cavity of the mold during clamping during molding. It is described that the resin is molded so as not to go around the lower surface (back surface) of the heat dissipation plate.

[0008]

As described in the above document, during transfer molding in the manufacture of a resin-sealed semiconductor device, the support plate fluctuates vertically due to the inflow pressure of the resin flowing into the cavity. It may tilt or tilt. In this case, a phenomenon may occur in which a part of the support plate or the wire is exposed on the surface of the package.

There is also a case where the wire is deformed by the inflow pressure of the resin and a short circuit occurs between adjacent wires.

Particularly in the present situation where the sealing body is becoming thinner, partial exposure of the wire may pose a serious problem.

An object of the present invention is to provide a semiconductor device excellent in moisture resistance in which parts of an object to be sealed such as wires and supporting plates are not exposed on the package surface, and a method of manufacturing the same.

[0012] The above and other objects and novel features of the present invention will become apparent from the description of the present specification and the accompanying drawings.

[0013]

The following is a brief description of an outline of typical inventions disclosed in the present application.

(1) A sealing body made of resin formed by transfer molding, a support plate located in the sealing body and supported by a support lead, and one end of which faces the periphery of the support plate and the other end. A plurality of leads that extend outside the sealing body, one or more semiconductor chips fixed to the main surface of the support plate, and a wire that electrically connects the electrodes of the semiconductor chip and the leads. In the semiconductor device, the support plate and the leads are made of a non-magnetic material, and a permanent magnet is fixed to the support plate so that the main surface side and the back surface side of the support plate have different magnetic poles. There is. A plurality of holes are provided in the support plate, and the permanent magnet is embedded in at least a part of the holes. The support plate and the leads are made of copper or a copper alloy.

Such a semiconductor device is manufactured by the following method.

A step of preparing a lead frame made of a non-magnetic material having a supporting plate for fixing the semiconductor chip, a step of fixing the semiconductor chip to the main surface of the supporting plate, an electrode of the semiconductor chip and a lead of the lead frame. A step of connecting the ends with a conductive wire; and after clamping the lead frame in a mold of a transfer mold device, injecting a melted resin into the cavity of the mold to support the support plate, the semiconductor chip, A method of manufacturing a semiconductor device, comprising a step of covering wires and the like with a sealing body, wherein a permanent magnet is fixed to the support plate in advance so that main surface side and back surface side of the support plate have mutually different magnetic poles. In addition, the lower mold and the upper mold of the mold are respectively fitted with electromagnets, and then the lead frame is clamped to the mold. At the same time, the magnetic force of each electromagnet is controlled to cause the permanent magnets to repel the electromagnets to support the supporting plate by magnetic force at a predetermined height in the cavity, and then melted resin in the cavity. To form the sealing body. The permanent magnet is embedded in at least a part of the hole provided in the support plate. The lead frame is made of copper or copper alloy.

(2) A sealing body made of resin formed by transfer molding, a wiring board positioned in the sealing body and supported by a supporting plate, and one end of which faces the circumference of the wiring board and the other end. A plurality of leads extending outside the encapsulant, one or more semiconductor chips and passive components fixed to the main surface of the wiring board, and a wire for electrically connecting desired electrodes and wirings. A semiconductor device having a hybrid integrated circuit structure including: the support plate and the leads made of a non-magnetic material, and the wiring board or the wiring board so that the main surface side and the back surface side of the wiring board have mutually different magnetic poles. A permanent magnet is fixed to the support plate. The wiring board is provided with a plurality of holes, and the permanent magnet is embedded in at least a part of the holes. The support plate and the leads are made of copper or a copper alloy.

Such a semiconductor device is manufactured by the following method.

A step of preparing a lead frame for supporting the wiring board by a support plate of the lead frame; a step of fixing one or more semiconductor chips or passive components on the main surface of the wiring board; Are connected with a conductive wire, and after the lead frame is clamped in the mold of the transfer mold device, the molten resin is injected into the cavity of the mold so that the wiring board, the semiconductor chip, the passive component A method of manufacturing a semiconductor device having a hybrid integrated circuit structure, the method including the step of covering wires and the like with a sealing body, wherein the main surface side and the rear surface side of the wiring board have different magnetic poles in advance. Alternatively, a permanent magnet is fixed to the support plate, and electromagnets are respectively incorporated in the lower mold and the upper mold of the mold, and then the lead frame is used. The mold is clamped in a mold, and the magnetic force of each electromagnet is controlled to cause the permanent magnet to repel the electromagnet to support the wiring board by magnetic force at a predetermined height in the cavity. Then, the melted resin is caused to flow into the cavity to form the sealing body. The permanent magnet is embedded in at least a part of the hole provided in the wiring board. The lead frame is made of copper or copper alloy.

According to the above-mentioned means (1), electromagnets are respectively incorporated in the upper and lower molds of the transfer molding apparatus, and in the lead frame which is the object to be sealed, the holes are formed in the holes provided in the support plate of the lead frame. Permanent magnets are embedded so that the main surface side and the back surface side of the support plate have mutually different magnetic poles. And at the time of molding,
A cavity is formed by controlling each electromagnet to repel a permanent magnet fixed to the support plate against each electromagnet to magnetically support the support plate at a predetermined height in the cavity, and then perform molding. The support plate does not move up and down even if the resin flows in strongly. As a result, even if the mold space on the main surface side and the back surface side of the support plate is designed thin, a part of the support plate and a part of the wire (wire loop) stretched between the semiconductor chip and the lead are sealed. It will not be exposed to or close to the surface of the stopper.

According to the above-mentioned means (2), as in the case of the above-mentioned means (1), electromagnets are respectively incorporated in the upper and lower molds of the mold of the transfer molding apparatus, and
In a lead frame which is an object to be sealed, a permanent magnet is embedded in a hole provided in a wiring board fixed to a support plate of the lead frame so that the main surface side and the back surface side of the wiring board have different magnetic poles from each other. is there. During molding, the electromagnets are controlled to repel the permanent magnets fixed to the wiring board against the electromagnets to support the wiring board at a predetermined height in the cavity by magnetic force, and then the molding is performed. As a result, the wiring board does not fluctuate vertically even if the resin flows into the cavity vigorously. As a result, even if the mold spaces on the main surface side and the back surface side of the wiring board are designed to be thin, a part of the wiring board or the support plate or one of the wires (wire loops) stretched between the semiconductor chip and the leads is formed. The part will not be exposed on the surface of the sealing body or come close to the surface.

[0022]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In all the drawings for describing the embodiments of the present invention, components having the same functions are denoted by the same reference numerals, and their repeated description will be omitted.

(Embodiment 1) FIGS. 1 to 4 are views relating to a method of manufacturing a semiconductor device which is an embodiment (Embodiment 1) of the present invention, and FIG. 1 is a schematic cross-sectional view showing a transfer mold state. 2 is a cross-sectional view showing a semiconductor device, FIG. 3 is a plan view showing a lead frame on which a semiconductor chip is fixed and wire bonding is performed, and FIG. 4 is a height of a supporting plate in a cavity in a method of manufacturing a semiconductor device. It is a schematic diagram which shows a control state.

As shown in FIG. 2, the semiconductor device 1 according to the first embodiment has a sealing body (package) 2 made of a resin (resin) that is flat in appearance, a peripheral surface of the package 2, and a package 4.
It is composed of a plurality of leads 3 protruding from the sides. For example, the thickness of the package 1 is about 1 mm.

The lead 3 extends inside and outside the package 2 and is of a gull wing type. A support plate 4 is located inside the package 2. The support plate 4 is also called a tab and is supported by a support lead (tab suspension lead) not shown in the figure. The support plate 4, the lead 3 and the support lead are made of a non-magnetic material,
For example, it is formed of a copper alloy plate. The support plate 4, the leads 3 and the support leads constitute a lead frame made of a copper alloy plate described later.

A semiconductor chip 6 constituting an IC or the like is fixed to the main surface of the support plate 4, that is, the upper surface in the figure, with a bonding material 5 (see FIG. 4) interposed. Further, the electrodes (not shown) on the upper surface of the semiconductor chip 6 and the tips of the leads 3 extending inside the package 2 are electrically connected via a conductive wire 7.

As shown in FIG. 3, the support plate 4 is provided with four holes 10 arranged in a cross pattern. The hole 10 is a hole for filling the resin forming the package 2 and improving the adhesive strength between the semiconductor chip 6 and the package 2.

A permanent magnet 11 is embedded in a part of the hole 10. The permanent magnet 11 has substantially the same thickness as the support plate 4, and the front and back surfaces have different magnetic pole surfaces. For example, in the first embodiment, the upper surface of the permanent magnet 11 is S as shown in FIGS.
It is embedded so that the pole and the lower surface become the N pole.

The permanent magnet 11 is fixed in the hole 10 by fitting. Since the permanent magnet 11 is also fixed to the support plate 4 by the bonding material 5 that fixes the semiconductor chip 6, the fitting does not have to be strong. As a result, the support plate 4 is not deformed by the fitting, and the mounting of the semiconductor chip 6 is not hindered.

Since the semiconductor device 1 of the first embodiment has a structure in which the permanent magnet 11 is fixed to the support plate 4 made of a non-magnetic material, it is possible to use the permanent magnet 11 in manufacturing the semiconductor device. Since the height position of the support plate 4 in the package 2 can be accurately defined and transfer molding can be performed in a state in which the posture is maintained, the support plate 4, the semiconductor chip 6, and a part of the wire 7 are part of the package 2.
Since it is not exposed to the surface of or of the package 2 and is not close to the surface of the package 2, the moisture resistance is high. That is, a part of the support plate 4 is not exposed on the back surface of the package 2 and is not so close to the back surface of the package 2 that the moisture resistance is impaired. Similarly, a part of the semiconductor chip 6 and the wires 7 are not provided. Part of it is not exposed to the main surface (upper surface) of the package 2 and is not so close to the back surface of the package 2 that the moisture resistance is impaired.

Further, since the permanent magnet 11 is fixed by fitting it into the hole 10 provided in the support plate 4, the work of attaching the permanent magnet 11 is facilitated and the attachment cost is reduced.

Next, a method of manufacturing the semiconductor device according to the first embodiment will be described. In manufacturing the semiconductor device 1, a lead frame 15 is prepared as shown in FIG. FIG. 3 shows the lead frame 15 in a state where the semiconductor chip 6 is fixed and wire bonding is completed.
The lead frame 15 is formed by patterning a non-magnetic material having a thickness of about 0.15 mm, for example, a copper plate or a copper alloy plate by etching or precision pressing.

The lead frame 15 is a strip body in which a plurality of unit lead patterns are arranged in series in one direction. The unit lead pattern is a pair of outer frames 16 extending in parallel.
And a pair of inner frames 17 connecting the pair of outer frames 16 and extending in a direction orthogonal to the outer frame 16 are formed in a frame.

A rectangular support plate (tab) 4 for mounting a semiconductor chip is provided in the center of the frame. The support plate 4 has a support lead (tab suspension lead) 21 extending from a support piece 20 protruding at four corners of the frame.
It is supported by.

The support plate 4 is provided with four holes 10 in a cross-shaped arrangement. This hole 10 is for the package 2
This is a hole for filling the resin that forms the resin and improving the adhesive strength between the semiconductor chip 6 and the package 2.

A permanent magnet 11 is embedded in a part of the hole 10 which is located at a part of the hole 10 on the outer side thereof. The permanent magnet 11 has substantially the same thickness as the support plate 4, and the front and back surfaces have different magnetic pole surfaces. For example, in the first embodiment, the permanent magnet 11 has the structure shown in FIG.
Further, as shown in FIG. 4, the upper surface is embedded so as to have the S pole and the lower surface is provided with the N pole.

The permanent magnet 11 is fixed in the hole 10 by fitting. The fixed state of the permanent magnet 11 may be maintained at least until the semiconductor chip 6 is fixed to the support plate 4. That is, in fixing the semiconductor chip 6, the semiconductor chip 6 is fixed to the support plate 4 via the bonding material 5, and the bonding material 5 fixes the permanent magnet 11 to the back surface of the semiconductor chip 6. As a result, when the permanent magnet 11 is fixed to the support plate 4 by fitting, a large fitting force that deforms the support plate 4 is unnecessary.

The permanent magnet 11 is, as described later,
Support plate 4 due to the flow of resin during transfer molding
It is desirable to dispose the permanent magnets 11 around the support plate 4, because the permanent magnets 11 are provided to prevent them from moving up and down and swinging.

On the other hand, each outer frame 16 and inner frame 17 of the frame
A plurality of leads 3 extend from the inside to the center of the frame. The leads 3 are parallel to each other on each side of the frame, and have a pattern in which the tips are brought close to the periphery of the support plate 4. Further, on each side, the lead 3 is
The pattern intersects with a narrow dam 22 provided between the supporting pieces 20. Therefore, each lead 3
Will be supported on the way by the dam 22. The dam 22 functions as a dam that prevents the melted resin from flowing out during transfer molding described later. The cantilevered lead portion inside the dam 22 is generally called an inner lead, and the outer portion is called an outer lead.

The support lead 21 is bent in a step shape in the middle. As a result, the support plate 4 is lower than the lead 3 by one step (see FIG. 2).

The outer frame 16 has guide holes 25,
26 are provided. The guide holes 25 and 26 are used as guides for transferring and positioning the lead frame 15. It should be noted that the lead frame 15 is plated at a desired portion as needed.

On the other hand, in the first embodiment, an electromagnet is incorporated in the mold 30 of the transfer molding apparatus. That is, the mold die 30 includes a lower die 31 and an upper die 32, as shown in FIGS. Lower mold 3
The lead frame 15 which is an object to be sealed on the main surface (top surface) of
By placing the lower mold 31 and the upper mold 32 together and performing mold clamping, the parting surface portions of the lower mold 31 and the upper mold 32 both become spaces, which are not shown in the drawing. ) 33, gate 34, cavity 35,
Air vents etc. are formed. The cull is a recessed portion that receives the melted and pressurized resin. Runner 33
Is a resin flow path extending from the cull to reach the cavity 35 directly or through the sub-runner.
The entrance portion of 5 becomes a gate 34. The air vent is an air guide path for guiding the air in the cavity 35 to the outside of the mold.

Electromagnets 41, 4 are provided on the inner side of the lower die 31 and the inner side of the upper die 32 on the bottom side and the ceiling side of the cavity 35.
2 is attached. The electromagnets 41 and 42 are installed parallel to the cavity bottom surface 46 or the cavity ceiling surface 47. The electromagnets 41 and 42 are cables 4
It is connected to the control device 45 via 3, 44. The control device 45 can magnetize the electromagnets 41 and 42 to a desired magnetic force. Further, the polarities of the electromagnets 41 and 42 can be changed. In the first embodiment, since the main surface (upper surface) side of the support plate 4 to which the semiconductor chip 6 is fixed becomes the S pole by the permanent magnet 11 and the back surface (lower surface) becomes the N pole, it is incorporated in the lower mold 31. The surface of the electromagnet 41 on the cavity side is the N pole, and the electromagnet 41 incorporated in the upper die 32.
The surface on the cavity side of is the S pole.

Next, the lead frame 15 is assembled. That is, as shown in FIGS. 3 and 4, the semiconductor chip 6 is fixed to the main surface of the support plate 4 to which the permanent magnet 11 is fixed, via the bonding material 5 (see FIG. 4). Further, an electrode (not shown) of the semiconductor chip 6 and the corresponding tip of the lead 3 are electrically connected by a conductive wire 7.

In the first embodiment, an example in which one semiconductor chip 6 is fixed to the support plate 4 will be described, but a plurality of semiconductor chips may be used.

Next, the lead frame 1 that has been assembled
As shown in FIGS. 1 and 4, the mold 5 is clamped to the mold 30 of the transfer mold device. After that, the control device 45 magnetizes the electromagnets 41 and 42 incorporated in the lower die 31 and the upper die 32 to predetermined magnetic forces. As a result, the upper surface (S pole) and the lower surface (N pole) of the permanent magnet 11 fixed to the support plate 4 are the upper surface (N pole) of the electromagnet 41 of the lower die 31 and the lower surface (S pole) of the electromagnet 42 of the upper die 32. Pole) is repelled by magnetic force. As a result, as shown in FIG. 4, the support plate 4 extends in parallel with the cavity bottom surface 46 and the cavity ceiling surface 47, and the height a of the mold space on the back surface side of the support plate 4 and the semiconductor chip 6 are increased. The height c of the mold space on the main surface side is constant over the entire area. The permanent magnet 11, that is, the support plate 4 is magnetically held (supported) by the electromagnets 41 and 42.

Next, from the gate 34 to the cavity 3
The melted resin 50 is caused to flow into the mold 5 for molding, and the sealed body (package) 2 covers the sealed plate (package) 2 such as the support plate 4, the semiconductor chip 6, the wires 7, and the tips of the leads 3.
At this time, since the permanent magnets 11 are held (supported) by the magnetic force by the action of the electromagnets 41, 42 and the permanent magnets 11, the melted resin 50 flowing into the cavity 35 vigorously Also does not move up and down. Therefore, the support plate 4 in which the permanent magnet 11 is embedded and the semiconductor chip 6 fixed on the support plate 4 do not move up and down.

As a result, the defect that the portion to be sealed is exposed on the surface of the package 2 does not occur. That is, the support plate 4 is not exposed on the back surface (lower surface) of the package 2 and the semiconductor chip 6 or a part of the wire 7 is not exposed on the main surface (upper surface) of the package 2.

Further, since the support plate 4 and the semiconductor chip 6 do not move up and down during the molding, the distance between the support plate 4, the semiconductor chip 6, the wires 7 and the surface of the package 2 becomes sufficient, and the moisture resistance is improved. Excellent package 2.

Next, the lead frame 15 is taken out from the mold 30. After that, unnecessary portions of the lead frame 15 are cut and removed. Further, the leads 3 projecting from the periphery of the package 2 are formed into a gull wing type. As a result, the semiconductor device 1 as shown in FIG. 2 is manufactured.

According to the method of manufacturing the semiconductor device of the first embodiment, since the support plate 4 and the semiconductor chip 6 do not move vertically in the transfer molding, the package 2 is supported on the surface of the object to be sealed. The plate 4, the semiconductor chip 6, the wire 7, etc. are not exposed, and the yield of the mold can be improved.

Further, since the supporting plate 4, the semiconductor chip 6, the wires 7, etc. are not located near the surface of the package 2, the moisture resistance of the semiconductor device is improved.

In the first embodiment, the permanent magnet 11 is fixed to the hole 10 of the support plate 4 by fitting, but the permanent magnet 11 may be fixed by using a bonding material. Also, the support plate 4
Main surface (upper surface) or the main surface of semiconductor chip 6 (upper surface)
Alternatively, the permanent magnet 11 may be fixed with an adhesive. When the permanent magnet 11 is bonded to the main surface of the semiconductor chip 6, the permanent magnet 1
In order to prevent the permanent magnet 11 from approaching the surface of the package 2, it is desirable that the thickness of 1 be the maximum loop height of the wire 7.

(Embodiment 2) FIG. 5 is a sectional view showing a semiconductor device having a hybrid integrated circuit structure which is another embodiment (embodiment 2) of the present invention, and FIG. It is a top view which shows the lead frame used.

The semiconductor device 1 having the hybrid integrated circuit structure according to the second embodiment is manufactured by using the lead frame to which the wiring board is fixed.

As shown in FIG. 5, the semiconductor device 1 according to the second embodiment has a package 2 formed of a resin having a rectangular flat shape in appearance as in the first embodiment, and a periphery of the package 2. It is composed of a plurality of gull wing-type leads 3 protruding from. The thickness of the package 2 is thicker than that of the first embodiment, and is, for example, about 2 to 3 mm.

In the semiconductor device 1 of the second embodiment,
The support plate 4 embedded in the package 2 has a rectangular frame shape as shown in FIG. And this support plate 4
A rectangular wiring board 60 is fixed to the main surface of the substrate with a bonding material.

Although not shown, the wiring board 60 is provided with wirings and electrodes (pads) on its main surface. For example, a fixing pad is provided in the portion where the semiconductor chip 6 is mounted. The passive component 6 such as a chip capacitor or a chip resistor is mounted on the portion where the passive component 61 is mounted.
A pad (electrode) to which one electrode is fixed is provided. Around the semiconductor chip 6, pads (electrodes) for wire bonding are provided. Further, pads (electrodes) for connecting the wires 7 connected to the leads 3 are provided in the peripheral portion of the wiring board 60.

FIG. 5 shows a state in which two semiconductor chips 6 and one passive component 61 are fixed to the main surface of the wiring board 60. Further, the electrodes of the semiconductor chip 6 and the wiring board 60.
Pads (or wirings) are electrically connected by conductive wires 7. Further, the pads on the peripheral portion of the wiring board 60 and the tips of the leads 3 extending into the package 2 are connected by a conductive wire 7.

In the second embodiment, the permanent magnet 11 is embedded in the hole 62 provided in the wiring board 60. The permanent magnet 11 may be fixed in the hole 62 of the wiring board 60 by fitting, or may be fixed by an adhesive. Permanent magnet 1
As shown in FIG. 6, 1 is provided at four corners of a rectangular wiring board 60. In order to prevent vertical fluctuation and shake of the wiring board 60 during transfer molding, it is desirable to arrange the permanent magnets 11 around the wiring board 60.

The permanent magnet 11 may be fixed on the wiring board 60, the support plate 4 or the semiconductor chip 6 with an adhesive. When the permanent magnet 11 is adhered to the main surface of the semiconductor chip 6, the thickness of the permanent magnet 11 should be set so that the loop height of the wire 7 is maximized so that the permanent magnet 11 is prevented from coming close to the surface of the package 2. It is desirable to achieve

As in the first embodiment, the permanent magnet 11 has an S pole on the main surface (upper surface) side for fixing the semiconductor chip 6 and an N pole on the back surface (lower surface) side.

The semiconductor device 1 having the hybrid integrated circuit structure according to the second embodiment is manufactured by the following method.

In manufacturing the semiconductor device 1, a lead frame with a wiring board as shown in FIG. 6 is prepared.

This lead frame 15 is the same as the lead frame of the first embodiment, except that the support plate 4 has a frame shape. A rectangular wiring board 60 is fixed to the support plate 4 via a bonding material (not shown). Since the support plate 4 has a plurality of semiconductor chips and passive components mounted thereon, the support plate 4 has a larger size than that of the first embodiment.

Although not shown, the wiring board 60 is provided with wirings and electrodes (pads) on the main surface (upper surface) as described above. For example, a fixing pad is provided in a portion where the semiconductor chip 6 is mounted, and a pad (electrode) to which an electrode of the passive component 61 is fixed is provided in a portion where the passive component 61 such as a chip capacitor or a chip resistor is mounted. The
Pads (electrodes) for wire bonding are provided on the peripheral surface of the semiconductor chip 6, and pads (electrodes) for connecting the wires 7 connected to the leads 3 are provided on the peripheral portion of the wiring board 60. ing.

Further, as shown in FIG. 6, holes 62 are provided at the four corners of the wiring board 60. The permanent magnet 11 is embedded in the hole 62. The permanent magnet 11 is fitted in the hole 62 or fixed by an adhesive. Permanent magnet 1
The thickness of 1 is the same as or thicker than the thickness of the wiring board 60. The thickness of the permanent magnet 11 is free as long as the lower surface is inside the back surface (lower surface) of the support plate 4 and the upper surface is inside the top portion of the loop of the wire 7.

In assembling the semiconductor device 1, a plurality of semiconductor chips 6 and passive components 6 are formed on the main surface of the wiring board 60 of the lead frame 15 by a conventional bonding method.
1 is installed. In FIG. 5, two semiconductor chips 6 and one passive component 61 are fixed to the main surface of the wiring board 60.

Next, the electrodes of the semiconductor chip 6 and the pads (or wirings) of the wiring board 60 are electrically connected by the conductive wires 7 by a conventional wire bonding method. Similarly, the pads on the peripheral portion of the wiring board 60 are connected to the tip portions of the leads 3 whose tips are brought close to the periphery of the wiring board 60 by the conductive wires 7.

Next, the lead frame 1 which has been assembled
The mold 5 is clamped in the mold of the transfer mold device and molded to form the package 2. Although not shown, the mold of the transfer mold device is
The same one as in the first embodiment is used. That is, the electromagnet 41 is incorporated in the lower die 31, and the electromagnet 42 is incorporated in the upper die 32.
The mold die 30 incorporating the is used.

The permanent magnet 11 fixed to the wiring board 60 of the lead frame 15 clamped in the mold 30 is
Electromagnets 41, 42 magnetized by the controller 45
By the repulsive state, the cavity 35 is magnetically supported (held) at a predetermined height. As a result, the wiring board 60 to which the permanent magnets 11 are fixed, the support plate 4 to which the wiring board 60 is fixed, the semiconductor chip 6 to be fixed to the wiring board 60, the semiconductor chip 6, or the wiring board 60 or the lead 3 are fixed. The wire 7 is held at the predetermined height of the cavity 35 by the magnetic force.

Therefore, even if the melted resin 50 is made to flow into the cavity 35, the melted resin 5 flowing in vigorously
Even if 0, the part of the object to be sealed such as the wiring board 60 does not move up and down. As a result, such a defect that the portion to be sealed is exposed on the surface of the package 2 does not occur. In addition, since the wiring board 60 and the semiconductor chip 6 do not move up and down during molding, the distance between the wiring board 60, the support plate 4, the passive component 61, the semiconductor chip 6, the wires 7 and the surface of the package 2 is sufficient. The package 2 has excellent moisture resistance.

Next, the lead frame 15 is taken out of the mold 30. Then, after removing unnecessary lead frame portions by cutting, molding is performed to form the leads 3 protruding from the package 2 in a gull wing type. As a result, the semiconductor device 1 having the hybrid integrated circuit structure shown in FIG. 5 is manufactured.

In the semiconductor device 1 having the hybrid integrated circuit structure according to the second embodiment, the sealed object portion is not exposed on the surface of the package 2 and the sealed object portion does not come close to the surface of the package 2. The moisture resistance is improved as well as the moisture resistance.

According to the method of manufacturing the semiconductor device having the hybrid integrated circuit structure of the second embodiment, since the wiring substrate 60 does not move up and down during transfer molding, the semiconductor device 1 having poor appearance and low moisture resistance can be obtained. It is possible to provide the semiconductor device 1 which is not required to be manufactured, can improve the manufacturing yield, and has high reliability and good moisture resistance.

In the second embodiment, since the support plate 4 has a rectangular frame shape, the back surface of the wiring board 60 is partially exposed. Therefore, a heat dissipation plate (heat spreader) may be provided on this exposed portion. The heat dissipation plate is formed of a metal having good thermal conductivity such as copper. The back surface of the heat sink is exposed on the back surface of the package 2.

In the case of this embodiment, since the wiring board 60 does not move up and down during transfer molding,
The resin does not adhere to the exposed back surface of the heat sink,
A semiconductor device having good heat dissipation can be manufactured. That is, when the semiconductor device of this embodiment is mounted, the heat dissipation plate comes into contact with the motherboard or the chassis, so that the heat generated in the semiconductor device is directly transferred to the motherboard or the chassis.

Although the invention made by the present inventor has been specifically described based on the embodiments, the present invention is not limited to the above embodiments, and various modifications can be made without departing from the spirit of the invention. Needless to say.

The present invention can be applied to a technique of sealing at least both surfaces of a plate-like object that fluctuates up and down by transfer molding.

[0080]

The effects obtained by the representative ones of the inventions disclosed in the present application will be briefly described as follows.

(1) A permanent magnet is fixed to a support plate of a lead frame made of a non-magnetic material so that the main surface side and the back surface side of the support plate have mutually different magnetic poles, and the lower mold of the transfer mold device is used. Electromagnets are built in the upper mold and the upper mold respectively, and at the time of molding, the magnetic forces of the electromagnets are controlled to cause the permanent magnets to repel each electromagnet so that the support plate is magnetically supported at a predetermined height in the cavity. Since the molten resin is then allowed to flow into the cavity to form the sealing body, the support plate and the semiconductor chip fixed to the support plate do not move up and down during molding, and the support plate, the semiconductor chip, the wire, etc. Since the part to be sealed is not exposed on the surface of the package or close to the surface, the mold yield can be improved and the moisture resistance is high. It is possible to provide a semiconductor device excellent.

(2) In manufacturing a semiconductor device having a hybrid integrated circuit structure in which a wiring board is fixed to the support plate, and a semiconductor chip or a passive component is fixed to the main surface of the wiring board and wire bonding is performed, the wiring board is used. Even in the structure in which the permanent magnets are fixed so that the main surface side and the back surface side of the wiring board have mutually different magnetic poles, the transfer mold apparatus incorporating electromagnets in the lower mold and upper mold of the mold is used. At the time of molding, the magnetic forces of the two electromagnets are controlled to cause the permanent magnets to repel each electromagnet to support the wiring board at a predetermined height in the cavity by magnetic force,
Then, since the melted resin is caused to flow into the cavity to form the sealing body, the wiring board, the support plate, and the semiconductor chip fixed to the wiring board do not move up and down during molding, and thus the wiring board, the support plate, and the semiconductor. Since the parts to be sealed such as chips and wires are not exposed to the surface of the package or close to the surface, the mold yield can be improved and the semiconductor of the hybrid integrated circuit structure excellent in moisture resistance is also provided. A device can be provided.

[Brief description of drawings]

FIG. 1 is a schematic cross-sectional view showing a transfer mold state in a method for manufacturing a semiconductor device according to an embodiment (Embodiment 1) of the present invention.

FIG. 2 is a cross-sectional view showing the semiconductor device of the first embodiment.

FIG. 3 is a plan view showing a lead frame to which a semiconductor chip is fixed and wire bonding is performed in the method for manufacturing a semiconductor device according to the first embodiment.

FIG. 4 is a schematic view showing a height control state of a support plate in a cavity in the method of manufacturing a semiconductor device according to the first embodiment.

FIG. 5 is a sectional view showing a semiconductor device having a hybrid integrated circuit structure according to another embodiment (Embodiment 2) of the present invention.

FIG. 6 is a plan view showing a lead frame used for manufacturing the semiconductor device of the third embodiment.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Semiconductor device, 2 ... Sealing body (package), 3 ... Lead, 4 ... Support plate, 5 ... Bonding material, 6 ... Semiconductor chip, 7 ...
Wire, 10 ... Hole, 11 ... Permanent magnet, 15 ... Lead frame, 16 ... Outer frame, 17 ... Inner frame, 20 ... Supporting piece, 21 ...
Support lead, 22 ... Dam, 25, 26 ... Guide hole, 30
... Mold type, 31 ... Lower mold, 32 ... Upper mold, 33 ... Runner, 34 ... Gate, 35 ... Cavity, 41, 42 ... Electromagnet, 43, 44 ... Cable, 45 ... Control device, 46 ...
Cavity bottom surface, 47 ... Cavity ceiling surface, 50 ... Melted resin, 60 ... Wiring board, 61 ... Passive component, 62 ... Hole.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code Agency reference number FI Technical indication // B29L 31:34

Claims (8)

[Claims] 1. A sealing body made of resin formed by transfer molding, a support plate positioned in the sealing body and supported by a support lead, and one end of which faces the periphery of the support plate and the other end of which is opposite. A plurality of leads extending outside the sealing body, one or more semiconductor chips fixed to the main surface of the support plate, and a wire electrically connecting the electrodes of the semiconductor chip and the leads. A semiconductor device having
The support plate and the lead are made of a non-magnetic material, and a permanent magnet is fixed to the support plate so that the main surface side and the back surface side of the support plate have different magnetic poles from each other. . 2. A sealing body made of resin formed by transfer molding, a wiring board positioned in the sealing body and supported by a support plate, and one end of which faces the periphery of the wiring board and the other end A plurality of leads extending outside the sealing body, one or more semiconductor chips and passive components fixed to the main surface of the wiring board, and wires for electrically connecting desired electrodes and wirings A semiconductor device having a hybrid integrated circuit structure, wherein the support plate and the lead are made of a non-magnetic material, and the main surface side and the rear surface side of the wiring board have different magnetic poles from each other or the support. A semiconductor device having a permanent magnet fixed to a plate. 3. The semiconductor according to claim 1, wherein the support plate or the wiring board is provided with a plurality of holes, and the permanent magnet is embedded in at least a part of the holes. apparatus. 4. The semiconductor device according to claim 1, wherein the support plate and the leads are made of copper or a copper alloy. 5. A step of preparing a lead frame made of a non-magnetic material having a support plate for fixing a semiconductor chip, a step of fixing the semiconductor chip to a main surface of the support plate, an electrode of the semiconductor chip and a lead frame. The step of connecting the lead tips with a conductive wire, and after clamping the lead frame to the mold of the transfer molding device,
A method of manufacturing a semiconductor device, comprising the steps of injecting a melted resin into a cavity of the mold and covering the support plate, the semiconductor chip, the wire, etc. with a sealing body. The permanent magnet is fixed to the support plate so that the front side and the back side have different magnetic poles, and electromagnets are respectively incorporated in the lower mold and the upper mold of the mold, and then the lead frame is molded in the mold. The mold was clamped, and the magnetic force of each electromagnet was controlled to cause the permanent magnet to repel the electromagnets to magnetically support the support plate at a predetermined height in the cavity, and then melted. A method of manufacturing a semiconductor device, characterized in that a resin is caused to flow into a cavity to form the sealing body. 6. A step of preparing a lead frame for supporting a wiring board by a support plate of the lead frame, a step of fixing one or more semiconductor chips or passive components to the main surface of the wiring board, a predetermined electrode and A step of connecting the wirings with a conductive wire; and, after clamping the lead frame in a mold of a transfer mold device, injecting a melted resin into a cavity of the mold to form the wiring board, the semiconductor chip, A method of manufacturing a semiconductor device having a hybrid integrated circuit structure, comprising a step of covering passive components, wires, etc. with a sealing body, wherein the main surface side and the back surface side of the wiring board have different magnetic poles in advance. A permanent magnet is fixed to the wiring board or the supporting plate, and electromagnets are respectively incorporated in the lower mold and the upper mold of the mold, and then the lead frame is used. The mold is clamped in a mold and the magnetic force of each electromagnet is controlled to cause the permanent magnets to repel the electromagnets to support the wiring board by magnetic force at a predetermined height in the cavity. Then, a method for manufacturing a semiconductor device is characterized in that the molten resin is allowed to flow into the cavity to form the sealing body. 7. The method of manufacturing a semiconductor device according to claim 5, wherein the permanent magnet is embedded in at least a part of a hole provided in the support plate or the wiring board. 8. The method according to claim 5, wherein the lead frame is formed of copper or a copper alloy.
13. The method for manufacturing a semiconductor device according to claim 1.