JPH04186662A - Semiconductor device and its manufacture - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a manufacturing technology for a semiconductor device equipped with a resin-sealed pancage having a resin insulating layer portion, and in particular to a manufacturing technology for a resin insulating layer portion. , relates to technology that is effective when used in the manufacture of transistor arrays equipped with a single in-line plastic pancage (5IP with heat sink) (hereinafter referred to as transistor arrays with heat sink) and resin-insulated power transistors.

[Conventional technology]

As a transistor array with a heat sink, there are multiple semiconductor pellets each having a transistor circuit built in, multiple tabs to which each semiconductor pellet is bonded, and each semiconductor pellet is arranged to correspond to each tab. A plurality of leads, a wire bridged between each semiconductor beret and the leads, a heat dissipation plate located close to the back surface of the tab group via a resin insulating layer, and a semiconductor pellet; tabs, parts of leads, wires,
There is also one that is equipped with a pan cage that seals a part of the heat sink with resin.

In this transistor array with a heat sink, the tab group and the heat sink need to be insulated. For this reason, by lifting the lead frame on which the tab group is integrated from the heat sink when molding the resin-sealed pancage, a gap is interposed between the tab group and the heat sink, and the sealing resin fills this gap. A resin insulating layer portion is formed.

An example of this kind of semiconductor device, a power IC equipped with a single in-line plastic pancage with a heat sink, is disclosed in Japanese Patent Application Laid-Open No. 63-5245.
There is Publication No. 6.

In addition, as a resin-insulated power transistor, a semiconductor beret, a tab to which the semiconductor pellet is bonded, multiple leads electrically connected to the semiconductor pellet bonded to the tab, a semiconductor beret, a tab, and a lead. A package in which the inner part of the tab is sealed with resin, and includes a sealing part on the semiconductor pellet bonding side of the tab, and a resin-sealing package consisting of an insulating layer part on the side opposite to the semiconductor pellet bonding side of the tab. There is something.

(Problem to be Solved by the Invention) However, in the method of manufacturing a transistor array with a heat sink as described above, the lead frame is lifted from the heat sink during molding of the resin-sealed pancage, and the gap between the tab and the heat sink is The inventor has discovered that since the resin insulating layer is formed on the resin-sealed package, the tab is deformed by the flow of resin during molding of the resin-sealed package, resulting in a short circuit between the tab and the heat sink. revealed by.

In order to avoid this short circuit, when the gap between the lead frame and the heat sink is set large during molding of the resin-sealed package, the resin insulation layer formed between the tab and the heat sink is Since the thickness of the tab increases, a problem arises in that the thermal resistance between the tab and the heat sink increases.

In addition, if the gap between the lead frame and the heat sink is set large, there is a possibility that the tab will be greatly deformed due to resin flow, and if the tab is greatly deformed, it will cause cracks, wire breaks, and short circuits. occurs.

In addition, in the resin-insulated power transistor as described above, when the resin-sealed pancage is molded, the lead frame is lifted from the bottom surface of the lower mold cavity recess, and a resin insulation layer is formed. The tab is deformed by the flow of resin during molding,
The resin insulating layer becomes thinner, and the dielectric strength performance deteriorates.

Therefore, if the resin insulating layer portion is set to be thick in order to avoid this, the thermal resistance will increase.

Furthermore, if a resin insulating layer is formed by a supporting member protruding from the tab and the supporting member being engaged with a part of the cavity to lift the tab from the bottom of the cavity, the resin-sealed package After molding, the supporting member is exposed to the outside of the resin-sealed package, which not only deteriorates the appearance performance but also deteriorates the wA edge pressure resistance.

An object of the present invention is to provide a semiconductor device and a method for manufacturing the same that can prevent tab deformation while ensuring low thermal resistance.

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

(Means for Solving the Problems) Representative inventions disclosed in this application will be summarized as follows.

In other words, a semiconductor bead, a tab to which the semiconductor belent is bonded, multiple leads electrically connected to the semiconductor pellet bonded to the tab, and the inner parts of the semiconductor pellet, tab, and leads are bonded with resin. A semiconductor device that is a pan cage to be sealed, and includes a resin-sealed pan cage that includes a sealing part on the semiconductor pellet bonding side of the tab and an insulating layer part on the side opposite to the semiconductor pellet bonding side of the tab. In this case, an inclined surface portion is formed on at least the edge of the outer peripheral edge of the tab opposite to the gate trace, and the end surface on the side opposite to the semiconductor pellet bonding side is edged, and the thickness becomes thicker toward the inside. It is characterized by being formed by

Further, a semiconductor pellet, a tab to which the semiconductor pellet is bonded, and a plurality of leads electrically connected to the semiconductor pellet bonded to the tab,
The device includes a heat sink facing the back side of the tab so as to be close to the tab via a resin insulating layer, and a package that seals the semiconductor pellet, the tab, a part of the lead group, and a part of the heat sink with resin. In the semiconductor device, at least the edge of the outer periphery of the tab opposite to the gate trace has an inclined surface portion, and the end surface opposite to the semiconductor pellet bonding side is edged, and the tab is curved inward (therefore, the wall thickness is thicker). It is characterized by being formed so that it is inclined.

[Effect]

According to the above-mentioned means, since the sloping surface portion is provided on the outer peripheral edge of the tab, the resin during molding of the resin-sealed package is evenly distributed above and below the tab by the guiding effect of the resin flow of the slanted surface portion. As a result, tab deformation due to resin flow imbalance is prevented. Therefore, local thickness reduction of the resin insulating layer,
This will prevent short circuits between the tab and the heat dissipation plate, as well as verent cracks, wire breakage, and short circuit failures.

On the other hand, since deformation of the tab is avoided, the thickness of the resin insulating layer can be set thin, and the thermal resistance of the resin insulating layer can be kept extremely small.

(Example 1) FIG. 1 is a side sectional view showing a transistor array with a heat sink that is an example of the present invention, and FIG. 2 is a partially cutaway plan view thereof.

FIG. 3 and subsequent figures are explanatory diagrams showing a method of manufacturing a transistor array with a heat sink, which is an embodiment of the present invention.

In this embodiment, the semiconductor device according to the present invention is configured as a transistor array with a heat sink used as a power transistor for driving a motor. This transistor array 10 with a heat sink is made up of four semiconductor pellets 1 each having a transistor circuit (not shown) built therein.
2, four tabs 7 to which each semiconductor pellet 12 is bonded by a bonding layer 11, a plurality of inner leads 6 and outer leads 4 disposed corresponding to each tab 7, and each A wire 13 bridged between the semiconductor pellet 12 and the inner lead 6, and a rectangular plate-shaped heat sink 22 located close to the back surface of the tab group 7 via a resin insulating layer 29. , semiconductor pellet 12, tab 7, inner lead 6
, the wire 13, and a package 28 that seals a portion of the heat sink 22 with resin.

An inclined surface portion 8 extends substantially all the way around the outer peripheral edge of the tab 7, and the end surface of the tab 7 opposite to the surface on which the semiconductor valent 12 is mounted is hemmed so that the wall thickness increases as it goes inward. In addition, a groove portion 9 as an irregularly shaped portion is formed on the negative surface. Also,
The heat dissipation plate 22 also has an inclined surface portion 23 formed to face the gate mark and be inclined so as to face the inclined surface portion 8 of the tab 7 . A guide portion 24 is integrally and protrudingly provided on the end face. This transistor array with a heat sink is manufactured by the following manufacturing method.

Next, a method of manufacturing a transistor array with a heat sink, which is an embodiment of the present invention, will be described. This explanation clarifies the details of the structure of the transistor array with a heat sink.

In the method for manufacturing a transistor array with a heat sink according to this embodiment, a multiple lead frame 1 shown in FIGS. 3 and 4 is used. This multiple lead frame 1 is made of a conductive material such as a copper material (copper or copper alloy) or a ferrous material (iron or iron alloy), and is formed into a roughly rectangular thin plate shape by pressing or etching. It is integrally molded, and a plurality of unit lead frames 2 are arranged in a horizontal row at equal pitches. Multiple lead frame
is equipped with an elongated outer frame (frame) 3 that is linearly connected with the unit lead frame 2.2 adjacent to each other, and the outer frame 3 has small holes 3a used as feed holes and positioning holes.
There are multiple locations arranged in a regular manner.

In each unit lead frame 2, 12 outer leads 4 are arranged at equal intervals in the longitudinal direction on one end side of the outer frame 3, and are integrally protruded in the right angle direction. A dam 5 is integrally constructed in each of the dams. Among these outer leads 4, inner leads 6 are integrally formed in the portions ahead of the dams 5 of eight outer leads, and tabs 7 are integrally formed in the other four outer leads.

The outer peripheral edge of each tab 7 has an inclined surface portion 8 that extends almost all the way around the entire circumference, and has an end surface (hereinafter referred to as a second major surface) opposite to the end surface on the pellet bonding side (hereinafter referred to as a first major surface), which will be described later. The walls are edged, and each wall is sloped so that the wall thickness gradually increases toward the inside. Furthermore, a groove portion 9 serving as an irregularly shaped portion is formed on the second main surface of each tab 7 and is arranged parallel to the extending direction of the outer lead 14 over substantially the entire length thereof.

In the multi-lead frame 1 configured as described above, in the pellet bonding process and the wire bonding process, as shown in FIG. 5 and FIG. 1 pellet each
2 are bonded to each other by a bonding layer 11 made of Ag paste or the like, and each pellet 12
Wires 13 are bridged between the bonding ink hats 12a and the inner leads 6, respectively. Thereby, the transistor circuit of each pellet 12 is electrically taken out to the outside by each outer lead 4 via its bonding pad 12a, wire 13, and inner lead 6.

Further, in the method of manufacturing a transistor array with a heat sink according to this embodiment, multiple heat sinks are used as shown in FIGS. 7, 8, and 9. That is, the multiple heat sink 21 includes the same number of unit heat sinks 22 as the multiple lead frame 1 described above, and is made of aluminum, which is an example of a material with good thermal conductivity, and is formed into a substantially rectangular thin plate shape. It is integrally formed by press working. The unit heat sink 22 is formed into a rectangular thin plate shape having a width approximately half that of the unit lead frame 2, and the short sides of adjacent unit heat sinks 22 and 22 are connected by the connecting portion 22 marks. They are integrally connected.

An inclined surface portion 23 is provided on the end surface (hereinafter referred to as the first main surface) of each unit heat sink 22 facing the unit lead frame 2.
It is arranged so as to substantially extend in the longitudinal direction in the substantially central part in the transverse direction, and the wall thickness gradually decreases from the end side where the rear mounting holes 26 and 27 are opened in the opposite direction. This inclined surface portion 23 is formed so that the inclined surface portion 8 on the tip side of the tab 7 is formed in a state where the unit heat sink 22 is opposed to the unit lead frame 2.
They are arranged to face parallel to each other. Further, a guide portion 24 is disposed on the first main surface of each unit heat sink 22 so as to extend in the transverse direction at approximately the central portion in the longitudinal direction, and a portion of the heat sink 22 itself is raised. As described later, the guide portion 24 is configured to work together with the inclined surface portion 23 to equally distribute the flow of resin to both sides in the longitudinal direction.

Each unit heat dissipation plate 22 has a pull-out stopper 25 on its side surface (thickness portion), which is disposed on the side surface portion that will be buried in the package after molding the resin-sealed package, which will be described later. The removal stopper 25 is integrally provided by press processing so as to protrude, and by protruding into the inside of the package in the shape of an engaging claw, the heat dissipation plate 22 can be removed from the resin-sealed pan cage. It is formed to be able to stop m.

Each unit heat sink 22 also has a pair of mounting holes 26 and 2.
7 are respectively arranged at one corner exposed from the pan cage after molding the resin-sealed package, which will be described later, at both ends in the longitudinal direction, and are opened so as to penetrate in the thickness direction, and one mounting hole 26 The mounting hole 27 is formed in a perfect circular shape, and the other mounting hole 27 is formed in an elliptical shape.

The multiple heat sink 21 configured as described above is combined with the multiple lead frames 1 bonded to pellets and wires as described above, and each unit heat sink 22 and each unit lead frame 2 has a Pancage groups to be resin-sealed are simultaneously molded using a transfer molding apparatus 30 as shown in FIGS. 10 to 12.

The transfer molding apparatus 30 shown in FIGS. 10 to 12 includes a pair of upper mold 31 and lower mold 32 that are clamped together by a cylinder device or the like (not shown). A plurality of sets of upper mold cavity recesses 33a and lower mold cavity recesses 33b are recessed in the mating surfaces of the upper mold and lower mold 32 so as to cooperate with each other to form the cavity 33. Bot 3 is placed on the mating surface of the upper die 31.
A plunger 35, which is moved forward and backward by a cylinder device (not shown), is inserted into the bot 34 so as to feed resin as a molding material. A cull 36 is arranged and recessed on the mating surface of the lower mold 32 at a position opposite to the bot 34, and a plurality of runners 37 are connected to the bot 34 on the mating surface of the upper mold 31, respectively. They are placed in a radial pattern. The other end of each runner 37 is connected to the upper cavity recess 33, and a gate 38 is formed at the connection portion so that resin can be injected into the cavity 33. In addition, on the mating surface of the lower mold 32, a lead frame relief recess 39 is recessed at a constant depth, which is a rectangle slightly larger than the outer shape of the lead frame and has a dimension approximately equal to the thickness thereof, so that the lead frame relief recess 39 can escape the thickness of the lead frame. has been done. Furthermore, a heat sink relief recess 4 is provided on the mating surface of the lower die 32.
0 can escape the thickness of the heat dissipation plate 22 in the lead frame relief recess 39 and the cavity recess 33b, so that it is recessed in a size that is approximately equal to the thickness of the heat dissipation plate 22 so that it is slightly larger than the outer shape of the heat sink 22. There is.

When a resin-sealed pancage is transfer-molded using the multiple lead frame l and the multiple heat sinks 21 having the above configuration, first, the multiple heat sinks 21 are made to correspond to the respective lower mold cavity recesses 33b. It is set by being dropped into the heat sink relief recess 4Q that is recessed in the heat sink. At this time, the slope portion 23 and the guide portion 24 are connected to the gate 38.
is faced with. In this state, most of each unit heat sink 22 is recessed into each lower mold cavity recess 33b.

Subsequently, the berent 12 of each unit lead frame 2 is inserted into each cavity 33 in the relief recess 39 in which the multiple lead frame 1 according to the above structure is sunk into the lower die 32.
They are arranged and set so that they are housed in each case.

At this time, each unit lead frame 2 is held within the cavity 33 with the tip side inclined surface portion 8 of the tab 7 being opposed to the gate 38.

Next, the upper mold 31 and the lower mold 32 are clamped.

Due to this mold clamping, the multiple lead frame 1 and the multiple heat dissipation plates 21 are held between the upper mold 31 and the lower mold 32.

Subsequently, resin 41 as a molding material is fed from the bot 34 by the plunger 35 into each cavity 33 through the runner 37 and the gate 38, and is press-fitted therein.

By the way, the resin 41 is inside the cavity 33 at the gate 3.
When the resin 41 is press-fitted from the tab 8, a large amount of the resin 41 is inserted into the cavity 33 because the space above the tab 7 is wide.
Moreover, due to the rapid flow of resin 41, each tab 7
A force that tends to deform it in the direction of the heat sink 22 may act on it.

Here, in the case of the conventional example where the tab is simply suspended from the heat sink, the tab is deformed in the direction of the heat sink, causing the tab to come into contact with the heat sink, or short circuits such as pellet cracks and wire breaks. Defects may occur.

However, in this embodiment, each tab 7 is formed with an inclined surface portion 8, and the heat sink 22 is formed with an inclined surface portion 23 and a guide portion 24, so that the tab 7 is provided with an inclined surface portion 8 in the direction of the heat sink plate 22. This prevents the application of forces that would cause it to deform.

As a result, the tab 7 is not deformed and maintains a predetermined state assumed in advance. Therefore, the occurrence of cracks, wire breaks, short circuits, etc. due to deformation of the tab 7 is prevented.

That is, the resin 41 press-fitted into the cavity 33 from the gate 38 tends to flow along the slope portion 23 around f of the heat sink 22 and into the narrow gap below the second main surface of the unit lead frame 2. is strengthened. Also,
When the resin 41 comes into contact with the guide portion 24 of the heat sink 22,
Since the resin 41 is evenly distributed left and right within the gap by the guide portion 24, it is evenly spread within the gap.

On the other hand, when the resin 41 press-fitted into the cavity 33 from the gate 3B comes into contact with the inclined surface part 8 formed on the outer peripheral edge of the tab 7, the resin 41 flows along the inclination. The tendency of the liquid to flow into the narrow gap on the lower side of the second main surface is strengthened.

Due to the flow of the resin 41 into the narrow gap and the strengthening direction, both the downward and upward forces acting on the unit lead frame 2 due to the flow of the resin above and below the unit lead frame 2 are approximately balanced, so that the tab 7 can be used as a heat sink. 22
Generation of forces that would cause deformation in the direction of is prevented.

Even if a slight force to deform the tab 7 in either the up or down direction acts on the tab 7, the bending stress on the tab 7 will be increased due to the groove 9 formed in the tab 7. Therefore, the tab 7 is prevented from being deformed.

Then, the resin 41 press-fitted into the cavity 33 diffuses within the small gap where each tab 7 and the heat sink 22 face each other, thereby forming the resin insulating layer portion 29 within the gap. The thickness of this resin insulating layer section 29 can be adjusted by appropriately setting the gap between the unit lead frame 2 and the heat sink 22, and the thinner the resin insulating layer section 29, the more the tab 7 Since the plate 22 approaches,
The heat radiation performance for the heat sink 22 through each tab 7 is improved. In this embodiment, the thickness of the resin insulating layer portion 29 is set to be extremely thin because there is no risk of short-circuiting between the tab 7 and the heat sink 22 due to deformation of the tab 7 due to resin flow. I can do it. Therefore, the heat dissipation performance is extremely good.

After the resin is injected, when the resin is thermoset and the resin-sealed packages 28 are molded, the upper mold 31 and the lower mold 32 are opened, and the resin-sealed packages 28 are grouped by ejector pins (not shown). is released from the mold. In this way, the composite body of the multiple lead frame 1 and the multiple heat sinks 21 in which the resin-sealed packages 28 have been molded is removed from the transfer molding apparatus 30.

Then, the pellet 12, the inner lead 6, the bonding wire 13, and a portion of the heat sink 22 are sealed with resin inside the package 28 molded with resin in this manner. In this state, the back surface of the heat sink 22 and the vicinity of the mounting holes 26 and 27 are exposed from the back surface and one side of the resin-sealed package 28.

After that, the multiple lead frames 1 and the multiple heat sinks 21 are cut into each unit lead frame 2 in a lead cutting and forming process.
The outer frame 3, connecting portion 22a and each dam 5 are sequentially cut off by a lead cutting device (not shown) for each unit heat sink 22, as shown in FIGS. 13, 14 and 15. As shown, a heatsink transistor array 10 is formed with a single in-line plastic pancage.

The transistor array 10 with a heat sink manufactured as described above is mounted on a printed wiring board, for example, as shown in FIGS. 13 to 15.

That is, the printed wiring board 42 has a through hole 43.
A plurality of through holes 43 are arranged so as to correspond to the outer leads 14 of the transistor array 10 with a heat sink and are opened so as to penetrate in the thickness direction, and a conductor layer portion 44 is formed on the inner periphery of the through hole 43. In addition, electrical wiring (not shown) is wired to this conductor layer portion 44. The transistor array 10 with a heat sink according to the configuration described above is set on a printed wiring board 42 by inserting each outer lead 14 into each through hole 43, and a solder mound 45 is formed by flow soldering or the like. Implemented by

Furthermore, if necessary, heat dissipation fins or the like (not shown) are attached to the heat dissipation plate 22 using the attachment holes 26 and 27.

When the transistor array 10 with a heat sink mounted in this manner is operated on the printed wiring board, the semiconductor pellet 12 generates heat. This semiconductor pellet 12
The heat is transferred to the heat sink 2 via the tab 7 and the resin insulation layer 29.
The heat is transmitted to the heat dissipation plate 22 and radiated to the outside from the heat dissipation plate 22. At this time, since the thickness of the resin insulating layer portion 29 is set to be extremely thin, the heat from the tab 7 is transmitted to the heat dissipation plate 22 extremely effectively.

According to the embodiment described above, the following effects can be obtained.

(1) By providing an inclined surface part on the tab and the heat sink and a resin guide part on the heat sink, it is possible to force the resin into the narrow gap between the tab and the heat sink when molding the resin-sealed pancake. This allows the downward force and upward force exerted on the tab by the flow of resin to be balanced, so it is possible to prevent the tab from being deformed by the flow of resin during resin-sealed pancake molding. It is possible to prevent pellet cranks, wire breakage, and short circuit defects caused by deformation.

(2) As described in (1) above, in order to prevent tab deformation caused by resin flow, the thickness of the resin insulation layer formed by molding the resin-sealed package between the tab and the heat sink. can be made extremely thin, the thermal resistance between the tab and lead group and the heat sink can be controlled to be low, and the heat radiation performance can be further improved.

Although the invention made by the present inventor has been specifically explained above based on Examples, it goes without saying that the present invention is not limited to the Examples and can be modified in various ways without departing from the gist thereof. Nor.

For example, the inclined surface portion of the tab is not limited to the entire outer periphery, but may be provided at least on the edge facing the gate.

The irregularly shaped portion of the tab is not limited to a groove, but may be a convex portion or the like, or may be omitted.

Further, the inclined surface portion and the guide portion of the heat sink may be omitted.

As shown in FIG. 16, if the tab relief recess 24A is formed on the first main surface of the heat dissipation plate 22A so as to escape from the downward deformation of the tab 7, in the unlikely event that the tab Even if the tab 7 is slightly deformed downward, the insulation gap between the tab 7 and the heat sink 22A can be maintained to a certain extent.

[Embodiment 2] FIG. 17 is a side sectional view showing a resin-insulated power transistor according to Embodiment 2 of the present invention, and FIG. 18 is a partially cutaway plan view thereof.

19 and 19 are explanatory diagrams showing a method of manufacturing a resin-insulated power transistor according to a second embodiment of the present invention.

In Example 2, the semiconductor device according to the present invention is configured as a resin-insulated power transistor (hereinafter simply referred to as a transistor).

The transistor 50 includes a semiconductor pellet 62 in which a transistor circuit (not shown) is built, a tab 57 to which each semiconductor pellet 62 is bonded via a bonding layer 61, and a tab 57 arranged to face the tab 57. Multiple inner leads 56 installed
and a wire 63 bridged between the outer lead 54 and each semiconductor pellet 62 and the inner lead 56;
Consisting of a sealing part 77 formed on the front side of the tab 57 and a thin resin insulation layer part 79 formed on the back side of the tab 57, the semiconductor pellet 62, the tab 57, the inner lead 56, and the wire 63 and a resin-sealed package.

The outer peripheral edge of the tab 57 is provided with an inclined surface portion 58 extending almost all the way around, and the end surface of the tab 57 opposite to the surface on which the semiconductor pellet 62 is mounted is hemmed so that the wall thickness increases toward the inside. It is formed at an angle. This transistor is manufactured by the following manufacturing method.

Next, a method for manufacturing a transistor, which is a second embodiment of the present invention, will be described. This description reveals details about the structure of the transistor.

The method for manufacturing a transistor according to Example 2 includes the 19th
The multiple chained frame 5 shown in Figures and Figure 20
1 is used. This multi-lead frame 51 is made of a conductive material such as a copper material (copper or copper alloy) or an iron material (iron or iron alloy), and is integrally formed into a roughly rectangular thin plate shape by pressing or etching. A plurality of unit lead frames 52 are arranged in a horizontal row at equal pitches. However, only one unit is shown in the drawing. The multiple lead frame 51 includes an elongated outer frame (frame) 53 that is linearly connected to adjacent unit lead frames 52 and 52, and the outer frame 53 has holes that are used as feed holes and positioning holes. small hole 53
A plurality of ``a'' are arranged regularly.

Each unit lead frame 52 has three outer leads 54.
are arranged at equal intervals in the longitudinal direction on one end side of the outer frame 53 and project integrally in the right angle direction, and dams 55 are integrally constructed between adjacent outer leads 54 and 54, respectively. ing.

Of these outer leads 54, an inner lead 56 is integrally formed in a portion ahead of the dam 55 of two outer leads, and a tab 57 is integrally formed in the other one.

A sloped surface portion 58 extends substantially all around the outer peripheral edge of the tab 57, and is used for pellet bonding g! to be described later. The end surface (hereinafter referred to as the first principal surface) and the opposite end surface (hereinafter referred to as the second principal surface) are bordered and are sloped so that the wall thickness gradually increases toward the inside. each formed. Further, a mounting hole 59 is provided in the widthwise central portion of the tab 57 on the opposite side of the outer lead 54, and is opened so as to penetrate through the thickness direction.

In the pellet bonding process and the wire bonding process, the multi-lead frame 51 configured as described above has a semiconductor on the tab 57 for each unit lead frame 52, as shown in FIGS. 21 and 22. Pellets 62 (hereinafter referred to as pellets) are bonded to each other by a bonding layer 61 made of Ag paste or the like, and a wire 6 is connected between the bonding pad 62a of each pellet 62 and the inner lead 56.
3 are each bridged. As a result, each pellet 62
The transistor circuit is the bonding pan)'62
a, the wire 63, and the inner lead 56 to be electrically taken out to the outside by each outer lead 54.

In the multi-lead frame 51 subjected to pellet and wire bonding in this way, the package group resin-sealed for each unit lead frame 52 is a transfer molded FF70 as shown in FIGS. 23 to 25. used and simultaneously molded.

The transfer molding apparatus 70 shown in FIGS. 23 to 25 includes a pair of upper mold 71 and lower mold 72 that are clamped together by a cylinder device or the like (not shown).
A plurality of upper mold cavity recesses 73a and lower mold cavity recesses 73b are respectively recessed in the mating surfaces of the upper mold 71 and the lower mold 72 so as to cooperate with each other to form the cavity 73. A bot 74 is placed on the mating surface of the upper mold 71.
A plunger 75, which is moved forward and backward by a cylinder device (not shown), is inserted into the bond 74 so as to feed resin as a molding material (hereinafter referred to as resin). A cull 76 is arranged and recessed in the mating surface of the lower mold 72 at a position opposite to the pore door 4, and a plurality of runners 77 are connected to the bots 74 on the mating surface of the upper mold 71, respectively. They are placed in a radial pattern. The other end of each runner 77 is connected to the upper cavity recess 73, and a gate 78 is formed at the connection portion so that resin can be injected into the cavity 73. In addition, on the mating surface of the lower die 72, a lead frame relief recess 79 is formed in a rectangular shape slightly larger than the outer shape of the lead frame so as to escape the thickness of the lead frame, and is sunk to a constant depth with dimensions approximately equal to the thickness of the lead frame. It is set up. Further, a core mold 8 is provided in the lower mold cavity recess 73b.
0 is disposed at a position near the gate 78 in the center portion in the width direction and stands vertically.

When the multi-lead frame 51 according to the above configuration is used to transfer mold a resin-sealed pancage,
First, the multiple lead frame 51 is inserted into the relief recess 79 into which the lower mold 72 is recessed, and the mounting hole The core mold 80 is inserted into the portion 59 and is inserted. At this time, each unit lead frame 52 is held in the cavity 73 with the tip side inclined surface portion 58 of the tab 57 being spaced between the gates 7 and 7.

Next, the upper mold 71 and the lower mold 72 are clamped.

Due to this mold clamping, the multiple lead frame 51 is attached to the upper mold 71.
and the lower die 72.

Subsequently, resin 81 as a molding material is fed from the bot 74 by the plunger 75 into each cavity 73 through the runner 77 and the gate 78, and is press-fitted therein.

By the way, the resin 81 is inside the cavity 73 at the gate 7.
When the resin 81 is press-fitted from the tab 57 into the cavity 73, a large amount of resin 81 rapidly flows into the cavity 73 due to the large space above the tab 57.
7 may be subjected to a force that tends to deform it toward the bottom surface of the lower mold cavity recess 73b.

Here, in the case of the conventional example in which the tab is simply floating on the bottom surface of the lower mold cavity recess, the tab is deformed toward the bottom surface, so that the tab comes into contact with or comes very close to the bottom surface, or Short circuit defects such as pellet cracks and wire breaks may occur.

However, in this embodiment, the tab 57 has an inclined surface portion 58.
, it is possible to prevent a force from acting on the tab 57 to deform it toward the bottom surface. As a result, the tab 57 is not deformed and maintains a predetermined state assumed in advance. Therefore, contact with or extremely close contact with the bottom surface of the tab 57 due to deformation of the tab 57, occurrence of pellet cracks, wire breakage, short circuit defects, etc. are prevented.

That is, when the resin 81 press-fitted into the cavity 73 from the 7th day of the gate comes into contact with the inclined surface portion 58 formed on the outer peripheral edge of the tab 57, the resin 81 flows along the inclined surface. The tendency of flowing into the narrow gap between the lower mold cavity recess 33b and the lower mold cavity recess 33b on the lower side of the second main surface is strengthened. Due to this tendency of the resin 81 to flow into the narrow gap and strengthen, both the downward and upward forces acting on the tab 57 due to the flow of resin above and below the tab 57 are approximately balanced, so that the tab 57 tends to deform in the direction of the bottom surface. The generation of forces is prevented.

Then, the resin 81 press-fitted into the cavity 73 diffuses within the narrow gap where the tab 57 and the bottom surface of the lower mold cavity recess 73b face each other, thereby forming the resin insulating layer portion 83 within the gap. become. The thickness of this resin insulation layer portion 83 can be adjusted by appropriately setting the gap between the unit lead frame 52 and the bottom surface of the cavity recess 73b. Since the outside air approaches, the heat dissipation performance through the resin insulating layer portion 83 of the tab 57 is improved. In this embodiment, since there is no risk of deformation failure of the tab 57 due to deformation of the tab 57 due to resin flow, the thickness of the resin insulating layer portion 83 can be set to be extremely thin. Therefore, the heat dissipation performance is extremely good.

After the resin is injected, when the resin is thermoset and the resin-sealed package 82 is molded, the upper mold 71 and the lower mold 72 are opened, and an ejector bottle (not orally transferred) is used to form a group of resin-sealed pancakes 82. is released from the mold. In this way, the multi-lead frame 51 on which the group of resin-sealed pancakes 82 has been molded is removed from the transfer molding apparatus 70.

Then, the pellet 62, the inner lead 56, and the bonding wire 63 are sealed with resin inside the package 82 molded with resin in this manner. Further, a mounting hole 84 is formed in the resin-sealed package 82 so as to pass through it in the vertical direction by the core mold 80, and this mounting hole 84 is used for mounting the transistor 50 on a heat sink, a printed wiring board, etc. It is configured so that it can be used for inserting fasteners and the like.

Thereafter, in a lead cutting and forming process, the multiple lead frame 51 is cut into the outer frame 53 and each dam 5 by a lead cutting device (not shown) for each unit lead frame 52.
5 is cut off to form a transistor 50, as shown in FIGS. 17 and 18.

The transistor 10 manufactured as described above is mounted on a printed wiring board, for example, as shown in FIGS. 26 and 27.

That is, as shown in FIGS. 26 and 27, when mounted on a printed wiring board 85 in an electronic device or the like, the resin-insulated power transistor 50 having the above structure is placed at a predetermined position on the board 85. Then, the resin insulating layer section 83 is brought into contact with the surface thereof. Subsequently, a fastener such as a self-tap screw member 87 is inserted into the mounting hole 84 from above the package 82 and screwed into the fastening hole 86 previously formed in the substrate 85, thereby attaching the resin-insulated power transistor 50. is fixed on the substrate 85.

In this way, the mounted resin insulated transistor 5
0 is operated on the printed wiring board 85, the semiconductor pellet 62 generates heat. This semiconductor pellet 62
The heat is transmitted to the printed wiring board 85 via the tab 57 and the resin insulating layer portion 83, and is radiated from the board 85 to the outside. At this time, since the thickness of the resin insulating layer section 83 is set to be extremely thin, the heat from the tab 57 is transmitted to the substrate 85 extremely effectively.

According to the embodiment described above, the following effects can be obtained.

(1) By providing an inclined surface part on the tab, during resin sealing pancage molding, the resin is forced to flow into the narrow gap between the tab and the bottom of the four lower mold cavities, and the resin flow acts. Since the downward force and upward force on the tab can be balanced, it is possible to prevent the tab from being deformed by resin flow during molding of the resin-sealed package, and to prevent the dielectric strength from decreasing due to the deformation of the tab. Pellet cracks, wire breaks, and short circuits can be prevented from occurring.

(2) As described in (1) above, in order to prevent the tab from deforming due to resin flow, the thickness of the resin insulation layer formed by molding the resin-sealed pancage between the tab and the outside air can be reduced. It can be made extremely thin, the thermal resistance between the tab and the lead group can be controlled to be low, and the heat dissipation performance can be further improved.

Although the invention made by the present inventor has been specifically explained above based on Examples, it goes without saying that the present invention is not limited to the Examples and can be modified in various ways without departing from the gist thereof. Nor.

For example, the inclined surface portion of the tab is not limited to the entire outer periphery, but may be provided at least on the edge facing the gate.

In the above explanation, the invention made by the present inventor was mainly applied to a transistor array with a heat sink and a resin-insulated power transistor, which are the background fields of application of the invention, but the invention is not limited thereto. The present invention can be applied to general semiconductor devices equipped with resin-sealed packages, such as semiconductor integrated circuit devices (SIP/IC with fins) equipped with a single in-line plastic package with a heat sink.

In particular, the present invention can be applied to manufacturing techniques for semiconductor devices in which a thin resin insulating layer is provided on the second main surface side of a tab, and excellent effects can be obtained.

〔Effect of the invention〕

A brief explanation of the effects obtained by typical inventions disclosed in this application is as follows.

By providing the tab with an inclined surface, the resin is forced to flow into the narrow gap below the tab during molding of the resin-sealed pancake, thereby balancing the downward and upward forces exerted on the tab by the resin flow. This prevents the tab from being deformed due to resin flow during molding of the resin-sealed package, and prevents pellet cranks, wire breaks, short circuits, and deterioration of dielectric strength performance due to tab deformation. can be prevented.

As mentioned above, since deformation of the tab due to resin flow is prevented, the thickness of the resin insulation layer formed by molding the resin-sealed package can be set to be extremely thin, reducing its thermal resistance. control, and the heat dissipation performance can be further improved.

[Brief explanation of the drawing]

FIG. 1 is a side sectional view showing a transistor array with a heat sink according to a first embodiment of the present invention, and FIG. 2 is a partially omitted plan view thereof. FIG. 3 shows a method for manufacturing a transistor array with a heat sink according to the first embodiment of the present invention, and FIG. 3 is a partially omitted plan view showing a multiple lead frame used in the manufacturing method. Figure 4 is a sectional view taken along the If-TV line in Figure 3, Figure 5 is a partially omitted plan view showing the pellet and after the wire bonding process, and Figure 6 is a sectional view taken along the 5th line ■-■. , Fig. 7 shows a multiple heat sink used in the manufacturing method of a transistor array with a heat sink, partially omitted. IX-IX arrow view l in FIG. 7 including
Figure 0 is a partially omitted vertical cross-sectional view showing the resin-sealed pancake molding process, Figure 11 is a partially omitted cross-sectional view along the X1XI line in Figure 10, and Figure 12 is a partially omitted view showing the state in which the upper mold is removed. FIG. 13 is a front view showing the mounted state of the transistor array with a heat sink, FIG. 14 is a side sectional view thereof, and FIG. 15 is a rear entrance thereof. FIG. 16 is a longitudinal sectional view showing a modification of Embodiment 1 of the present invention;
It is. FIG. 17 is a side sectional view showing a resin insulated power transistor according to a second embodiment of the present invention, and FIG. 18 is a partially cutaway plan view thereof. FIG. 19 and subsequent figures show a method for manufacturing a resin-insulated power transistor according to a second embodiment of the present invention, and FIG. 19 is a partially omitted plan view showing a multiple lead frame used in the manufacturing method. Figure 20 is a cross-sectional view along the xX-xX line in Figure 19, Figure 21 is a partially omitted plan view showing the pellet and wire bonding process after the process, Figure 22 is a cross-sectional view of the fir tree in Figure 21, and Figure 23 is a cross-sectional view of the fir tree in Figure 21. FIG. 24 is a partially omitted longitudinal sectional view showing the resin-sealed package molding process; FIG. 24 is a partially omitted sectional view of FIG. 23; FIG. 25 is a partially omitted plan view showing the state with the upper mold removed; FIG. 26 27 is a side cross-sectional view showing the mounting state of the resin-insulated power transistor, and FIG. 27 is a front cross-sectional view thereof. DESCRIPTION OF SYMBOLS 1...Multiple lead frame, 2...Unit lead frame, 3...Outer frame, 3a...Small hole, 4...Outer lead, 5...Dam, 6...Inner lead, 7...
・Tough, 8...Slope part around A, 9...Groove part (unusual shape part), 10...Transistor array with heat sink, 11...
・Bonding layer, 12... Pellet, 12a...
Bonding band, 13... Wire, 21... Multiple heat sink, 22... Unit heat sink, 23... Inclined surface portion, 24... Guide portion, 24A... Relief recess, 25...
...Removal stop part, 26.27...Mounting hole, 28...
Resin-sealed pan cage, 29...resin insulation layer portion 30...
- Transfer molding device, 31... Upper mold, 32... Lower mold, 33... Cavity, 33a... Upper mold cavity four parts, 33b... Lower mold cavity recess, 34
... Bot, 35... Plunger, 36... Cal, 37... Runner, 38... Gate, 39... Lead frame escape recess, 40... Heat sink escape recess, 4
1... Resin, 42... Printed wiring board, 43.
...Through hole, 44...Conductor layer portion, 45...Solder mound portion, 50...Resin insulated power transistor, 51...Multiple lead frame, 52...Unit lead frame, 53... ...Outer frame, 53a...Small hole, 54
...Outer lead, 55...Dam, 56...Inner lead, 57...Tab, 58...Slope portion, 59
...Mounting hole, 61...Bonding layer, 62...
・Pellet, 62a...Bonding pad, 63・
...Wire, 70...Transfer molding device, 71.
... Upper mold, 72... Lower mold, 73... Cavity,
73a...Upper mold cavity recess, 73b...Lower mold cavity recess, 74...Bot, 75...Plunger, 76...Cull, 77...Runner, 78...
・Gate, 79...Lead frame escape recess, 80・
... Core mold, 81 ... Resin, 82 ... Resin sealing bar cage, 83 ... Resin insulation layer part, 84 ... Mounting hole, 85 ... Printed wiring board, 86 ...・Fastening hole,
87... Eagle member. Agent Patent Attorney Tatsuya Kajihara No. 151! 1 No. 161! ! Toki117 M5Q Fig. 18 Fig. 20 Fig. 26 Fig. 27

Claims (1)

[Claims] 1. A semiconductor pellet, a tab to which the semiconductor pellet is bonded, a plurality of leads electrically connected to the semiconductor pellet bonded to the tab, and a semiconductor pellet, a tab, and a lead. A package whose inner part is resin-sealed, and includes a resin-sealed package consisting of a sealing part on the semiconductor pellet bonding side of the tab and an insulating layer part on the opposite side of the tab to the semiconductor pellet bonding side. In the semiconductor device, the outer peripheral edge of the tab has an inclined surface portion at least on the edge opposite to the gate trace, the end surface opposite to the semiconductor pellet bonding side is bordered, and the wall thickness increases as it goes inward. What is claimed is: 1. A semiconductor device characterized in that the semiconductor device is formed so as to be inclined so that 2. The semiconductor device according to claim 1, wherein a deformed portion is formed on an end surface of the tab opposite to the semiconductor pellet bonding side. 3. A semiconductor pellet, a tab to which the semiconductor pellet is bonded, a plurality of leads electrically connected to the semiconductor pellet bonded to the tab, and a plurality of leads that are close to the back surface of the tab via a resin insulation layer. In the semiconductor device, the semiconductor device includes a heat dissipation plate that faces each other, and a package that seals a semiconductor pellet, a tab, a part of the lead group, and a part of the heat dissipation plate with resin, at least a gate mark on the outer periphery of the tab. A sloped surface portion is formed on an end face opposite to the semiconductor pellet bonding side, the end face opposite to the semiconductor pellet bonding side is edged, and the wall thickness becomes thicker toward the inside. Semiconductor equipment. 4. The semiconductor device according to claim 3, wherein an inclined surface portion is formed on the heat sink so as to face the gate trace and to face the inclined surface portion of the tab. 5. The semiconductor device according to claim 3, wherein a guide portion is formed on the heat sink so as to guide the resin. 6. At least on the outer peripheral edge of the tab of the lead frame, at least on the edge opposite to the gate mark, the inclined surface portion is edged on the side opposite to the semiconductor pellet bonding side, and the wall thickness increases as it goes inward. A step of bonding a semiconductor pellet onto the tab of the lead frame and electrically connecting the semiconductor pellet to a lead of the lead frame; A step of forming the inclined surface portion of the tab. The lead frame is set in a molding device while facing the gate of the device, and resin is injected into the cavity of this molding device to form a resin-sealed package that seals a portion of the semiconductor pellet, tab, and lead with the resin. 1. A method for manufacturing a semiconductor device, comprising: a step of molding the device so as to form the semiconductor device.