JPH03191553A - Semiconductor device and manufacture thereof - 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] [Industrial Application Field] The present invention relates to a manufacturing technology for a semiconductor device equipped with a heat sink;
In particular, with regard to insulation technology between heat sinks and tabs, for example, transistor arrays that are installed in single in-line plastic packages with heat sinks (5IP with heat sinks)
Hereinafter, we will discuss techniques that can be effectively used to manufacture transistor arrays with heat sinks.

[Prior Art] A transistor array with a heat sink includes a plurality of semiconductor pellets each having a transistor circuit built therein, a plurality of tabs to which each conductive pellet is bonded, and a conductor pellet corresponding to each tab. Are they arranged in each? 3I Several leads, a wire bridged between each semiconductor pellet and the lead, a heat sink positioned close to the back surface of the tab group via the resin MA curb section, and the semiconductor pellet. , tab, part of lead,
Some devices include wires and a package that seals a portion of the heat sink with resin.

In this transistor array with a heat sink, the tab group and the heat sink need to have an ISA edge. For this reason, by lifting the lead frame on which the tab group is integrated from the heat sink when molding the resin-sealed package, 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.

Note that the Power 10, which is a semiconductor device of this type and is equipped with a single inline-blast package with heat dissipation Mi, is described as an example in Japanese Patent Application Laid-Open No. 61-524.
There is a publication No. 56.

[Problem to be solved by the invention]

However, in this method of manufacturing a transistor array with a heat sink, the lead frame is lifted off the heat sink during molding of the resin-sealed package, so that a resin insulation layer is formed between the tab and the heat sink. Because, Il
! Jn=The inventor of the present invention has revealed that there is a problem in that the tab is deformed by the flow of resin during molding of the sealed package, resulting in a short circuit between the tab and the heat sink.

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 large (if set, there is a possibility that the tab will be significantly deformed due to resin flow, and if the tab is significantly deformed, it will cause pellet cracks and wire I! yI line or short circuit failure occurs.

SUMMARY OF THE INVENTION An object of the present invention is to provide a semiconductor device and a method for manufacturing the same that can prevent the occurrence of tough 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 to solve the problem]

An overview of typical inventions disclosed in this application is as follows.

That is, 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 adjacent to the back surface of the tab via a resin insulating layer. The heat sink, semiconductor bullet, tab,
- A semiconductor device comprising a package in which a part of the board group and a part of the heat sink are sealed with resin, wherein the resin insulating layer portion is sealed by adjusting the gap between the heat sink and the tab. It is characterized by being provided with an insulating gap adjustment part that controls the thickness.

[Effect]

According to the above-mentioned means, since the heat sink is provided with the gap adjustment section, even if the tab is deformed in the direction of the heat sink due to the flow of resin during molding of the resin-sealed package, the deformation will be prevented. is prevented by the gap adjustment section. Therefore, short circuits between the tab and the heat sink, bullet cracks, wire breakage, and short circuit failures can be prevented.

On the other hand, since the MII gap adjustment part can be formed extremely thin, the gap between the tab and the heat sink becomes small.
Since the thickness of the resin insulating layer portion formed between them is reduced, the thermal resistance therebetween is suppressed to an extremely low level.

〔Example〕

FIG. 1 is a side sectional view showing a transistor play with a heat sink according to an embodiment of the present invention, and FIG. 2 is a partially cutaway plan view thereof.

Figure 3 and subsequent figures show a transistor array with a heat sink, which is an embodiment of the present invention! ! ! FIG.

In this embodiment, the semiconductor device IA 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 play 10 with a heat sink includes four semiconductor pellets 1 each having a transistor circuit (not shown) built therein.
9, and four tabs 17 to which each semiconductor pellet 19 is bonded by a bonding layer I8,
A plurality of inner leads 16 and outer leads 14 arranged to correspond to each tab I7, a wire 20 bridged between each semiconductor belenium 19 and the inner lead 16, and a group of tabs 17 A rectangular plate-shaped heat dissipation plate 22 located close to the back side of the board with a wood insulating layer section 29 interposed therebetween, a semiconductor pellet 19, a tab 17,
The inner lead 16, the wire 20, and a package 28 for resin-sealing a part of the heat sink 22 are provided, and the heat sink 22 has a gap adjustment part 23 for controlling the gap with the group of tabs 17. In addition to being integrally raised and protruding, an insulated IiN portion 24 is formed on the contact surface of the gap adjustment portion 23 with the group of tabs 17. This transistor array with a heat sink is constructed as follows. Manufactured using a 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 of manufacturing a transistor array with a heat sink according to this embodiment, a multiple lead frame 11 shown in FIGS. 3 and 4 is used. This multiple lead frame 11
Such as copper-based materials (copper or copper alloys) or ferrous materials (iron or iron alloys), etc! ! It is integrally formed into a roughly rectangular thin plate shape by pressing or etching using an electrical material, and is made of a plurality of unit lead frames 1.
2 are arranged side by side in a horizontal row with equal pinch. The multiple lead frame 11 has adjacent unit lead frames J-12, 12@
(C frame) 1
3, and the outer frame 13 has a plurality of regularly arranged small holes 13a used as feed holes and positioning holes.

Each unit lead frame 12 has 12 outer leads 1.
4 are arranged at equal intervals in the longitudinal direction on one end side of the outer frame 13,
Each of the outer leads 14 and 14 is integrally protruded at a right angle, and a dam 15 is integrally installed between adjacent outer leads 14 and 14, respectively.

Among these outer leads 14, inner leads I6 are integrally formed in the portions ahead of the dam 15 of eight outer leads, and tabs 17 are integrally formed in the other four outer leads.

like this! : ill constructed multi-lead frame 1
1, in the pellet bonding process and the wire bonding process, a fifth
As shown in the figure and FIG. 6, each pellet 19 is bonded onto each tab 17 with a bonding layer 18 made of Ag paste or the like, and the bonding pad 19a of each pellet 19 and the inner lead 16 are bonded to each other. A wire 20 is bridged between them. As a result, the transistor circuit of each pellet 19 is connected to its bonding pad 19a, wire 20, and inner lead I.
6 and are electrically taken out to the outside by each outer lead 14.

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 dissipation plate 21 is made of the same number of unit heat dissipation plates 22 as the above-described multiple lead frame 11, 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 Mi22 is formed into a rectangular thin plate shape having a width approximately half that of the unit lead frame 12, and the unit heat sink Mi22 is formed into a rectangular thin plate shape having a width approximately half that of the unit lead frame 12.
Their short sides are integrally connected to each other by a connecting portion 22a.

Four gap adjustment parts 23 are arranged on the first main surface of each unit heat sink 22 at positions corresponding to the respective tabs 17 on the unit lead frame 12, so that a part of the heat sink 22 itself can be adjusted to the second main surface. Each is raised by being pushed up from the surface side by press working. An insulating layer portion 24 made of aluminum oxide is formed on the surface of this multiple heat dissipation plate 21 by anodizing the entire surface, and therefore, an insulating layer portion 24 is formed on the upper surface of the gap adjustment portion 23. is formed.

Each unit heat sink 22 has a removal stopper 25 on its side (ff
After molding the resin-sealed puff cage (described later), it is placed on the side surface of the package that will be buried inside the package, and is integrally formed by press processing so as to protrude outward in the radial direction. The removal preventing portion 25 is formed to protrude into the inside of the package in the shape of a retaining claw to prevent the heat sink 22 from being removed from the package.

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 package 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 in this manner is assembled with the multiple lead frame 1 which is pellet- and wire-bonded as described above, and each unit heat sink 22 and each unit lead frame 2. A group of packages 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 four parts 33a and lower mold cavity four parts 33b are respectively recessed in the mating surfaces of the upper mold 3I and the lower mold 32 so as to cooperate with each other to form the cavity 33. A bot 34 is placed on the mating surface of the upper mold 31.
A plunger 35, which is moved forward and backward by a cylinder device (not shown), is inserted into the bond 34 so as to feed resin as a molding material (hereinafter referred to as resin). 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 33a, and a gate 3B 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 40 is provided on the mating surface of the lower mold 32.
In order to escape the thickness of the heat dissipation plate 22 in the lead frame relief recess 39 and the cavity recess 33b, the heat dissipation plate 22 is recessed so as to have a slightly larger outer shape and a size substantially equal to the thickness thereof.

When transfer molding a resin-sealed package using the multiple lead frame 11 and multiple heat sinks 22 having the above configuration, first, the multiple heat sinks 21 are immersed so as to correspond to the respective lower mold cavity recesses 33b. It is dropped into the provided heat sink recess 40 and inserted. In this state, most of each unit heat sink 22 is recessed into each lower mold cavity recess 33b.

Subsequently, the pellets 1, 1 in each unit lead frame 12 are accommodated in each cavity 33 in the relief recess 39 in which the multiple lead frame 11 according to the above structure is sunk into the lower die 32. It is placed like L and is given as cent. At this time, tab 1 of each unit lead frame 12
On the back surface of the seventh group, unit heat radiation Fi is held in the cavity 33 in a state joined to the upper surface of the gap adjustment part 23 of 22.

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

Due to this mold clamping, the multiple lead frame 11 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 through the runner 37 and the gate 38 into each cavity 33 and press-fitted therein.

By the way, the resin 41 is inside the cavity 33 at the gate 3.
8, each tab 1 is pressed in by the flow of resin 41.
7 may be subjected to a force that tends to deform it toward the heat sink 22 . 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, the gap adjustment part 23 is provided protrudingly on the heat sink 22, and each tab 17 is supported by the gap adjustment part 23 on the heat sink 22. Even if a force trying to deform the tab 17 in the direction of Fi23 is applied, the tab 17 is not deformed and maintains a predetermined shape assumed in advance. Therefore, occurrence of pellet cracks, wire breaks, short circuits, etc. due to deformation of the tab 17 is prevented.

In addition, since the insulating layer part 24 is formed on the contact surface of the gap adjustment part 23 and the tab 17, the gap adjustment part 23 and the tab 1
Even if the tabs 17 and 7 are in contact with each other, a short circuit failure between the tabs 17 and the heat sink 22 does not occur.

Then, each tab 17 press-fitted into the cavity 33 and the heat radiating plate 22 go around into a small gap where they face each other, and a resin insulating layer part 29 is formed around the gap adjustment part 23. The thickness of this resin insulating layer section 29 can be adjusted by setting the height of the gap adjustment section 23, and the thinner the resin insulating layer section 29 is, the more
Since these are close to each other, the heat dissipation performance for the heat sink 22 through each tab 17 is improved. In this embodiment, the thickness of the resin insulating layer portion 29 is set to be extremely thin so that there is no risk of short-circuiting between the tab 17 and the heat sink 22 due to deformation of the tab 17 due to resin flow. I can do it. Therefore, the heat dissipation performance is extremely good.

After injection, the resin is thermally cured to form a resin-sealed package 2.
8 is molded, the upper mold 31 and the lower mold 32 are opened, and the groups of packages 28 are released from the mold by an ejector bin (not shown). In this way, the composite body of the multiple lead frame 11 and the multiple heat sinks 21 formed into the package 20 group is removed from the transfer molding apparatus 30.

Then, inside the package 28 molded with resin in this way, parts of the pellet 11, the inner lead 16, the bonding wire 20, and the heat sink 22 are sealed with resin. 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 frame II and the multiple heat dissipation Fi,
2], in the lead cutting and forming process, the outer frame 13, the connecting portion 22a, and each dam 15 are sequentially cut off for each unit lead frame 12 and unit heat sink 22 by a lead cutting device (not shown). Figures 14 and 1
As shown in Figure 5, sync, inline,
A transistor array lO with a heat sink is formed, which includes a plastic package.

The transistor array IO 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 lO 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. At the same time, this conductor layer section 4
4 is wired with electrical wiring (not shown). Then, the transistor array 10 with a heat sink having the above configuration is set on the 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 provided on the heat dissipation plate 22 using the mounting holes 26 and 27.

When the transistor array 10 with a heat sink mounted in this manner is operated on the printed circuit board,
The semiconductor pellet 19 generates heat. This semiconductor pellet 1
9 is transmitted to the heat sink 22 via the tab 17 and the resin insulating layer portion 29, and is radiated from the heat sink 22 to the outside.

At this time, since the thickness of the resin insulating layer portion 29 is set to be extremely thin, the heat from the tab 17 is transmitted to the heat radiation vi 22 extremely effectively.

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

(1) An insulating gap adjustment part is provided on the heat sink to adjust the gap between the tab and the tab, and the back side of the tab is brought into contact with this gap adjustment part during molding of the resin-sealed package, thereby molding the resin-sealed package. Since the tab can be supported by the gap adjustment section, it is possible to prevent the tab from being deformed by resin flow during molding of the resin-sealed package.
It is possible to prevent pellet cracks, wire breakage, and short circuit defects caused by tab deformation.

(2) By lowering the height of the insulating gap adjustment part in (1) above, the thickness of the mDtEAuM part formed by molding the resin-sealed package between the tab and the heat sink is set to be extremely thin. Therefore, 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 insulating gap adjustment part is not limited to being formed by partially raising the heat sink, but may be formed at a position opposite to the tab 17 on the first main surface of the heat sink 22, as shown in FIG. The gap adjusting portion 23A made of an insulating tape may be configured by attaching an insulating tape 24A to the insulating tape 24A.

Furthermore, as shown in FIG. 17, by pasting the insulating sheet 24B over the entire first main surface of the heat sink 22, 1! The gap adjustment section 23B may be composed of an edge sheet.

In the above explanation, the invention made by the present inventor was mainly applied to a transistor array with a heat sink, which is the background field of application, but the invention is not limited to this, and the present invention is not limited to this. - It can be applied to all semiconductor devices equipped with tabs and heat sinks, such as semiconductor integrated circuit devices (SIP/IC with fins) that clean puff cages.

〔Effect of the invention〕

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

An insulating gap adjustment part is provided on the heat sink to adjust the gap between the tab and the tab, and the back side of the tab is brought into contact with this gap adjustment part during molding of the resin-sealed package. This prevents the tab from being deformed by resin flow during molding of the resin-sealed puff cage, and prevents pellet cracks, wire breaks, and short circuits caused by tab deformation. can.

By lowering the height of the insulating gap adjustment section, the thickness of the resin insulation layer formed by molding the resin sealing package between the tab and the heat sink can be set to be extremely thin. Moreover, the thermal resistance between the lead group and the heat sink can be controlled to be small, and the heat radiation performance can be further improved.

[Brief explanation of drawings]

FIG. 1 is a side sectional view showing a transistor array with a heat sink according to an embodiment of the present invention, and FIG. 2 is a partially cutaway plan view thereof. FIG. 3 and subsequent figures show a method of manufacturing a transistor play with a heat sink, which is an embodiment of the present invention. FIG. 3 is a partially omitted plan view showing a multiple lead frame used in the manufacturing method, and FIG. The figure is a sectional view taken along the rV-rl line in Fig. 3, Fig. 5 is a partially omitted plan view showing the bullet and after the wire bonding process, and Fig. 6 is a sectional view taken along the Vl-117I line in Fig. 5. , 7th
The figure shows a multiple heat sink used in the method for manufacturing a transistor array with a heat sink, with some parts omitted.
-■ View from the arrow, Figure 9 is the 1st O from the ■-LX arrow in Figure 7, including a partial cross section.
The figure is a partially omitted cross-sectional view showing the resin-sealed package molding process. Figure 1I is a partially omitted cross-sectional view taken along lines XI- and XI in Figure 10. Figure 12 is a partially omitted cross-sectional view showing the E-shaped state. 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 view thereof. FIG. 16 is a longitudinal section showing another embodiment of the present invention; FIG. 17 is a longitudinal section showing another embodiment of the invention. IO...Transistor array with heat sink, 11...Multiple lead frame, 12...-Unit lead frame, 1
3...Outer frame, 13a...Small hole, 14...Outer lead, 15...Dam, 16...Inner lead, ]7
...Tab, 18--Bonding layer, 19... Pellet, 19a... Bonding band, 20...
Wire, 21...-Multiple heat sink, 22...Unit heat sink, 23.23A, 23B...Gap adjustment section, 24-...
Insulating layer portion, 24A...Insulating tape, 24B...Insulating sheet, 25--Removal stop portion, 26.27...Mounting hole, 28...-Resin sealing puff cage, 29-...Resin Insulating layer portion, 30...Transfer molding device, 31--Upper mold, 32--Lower mold, 33--Cavity, 33a
...Upper mold cavity recess, 33b...Lower mold cavity recess, 34...Bot, 35...Plunger, 36...Cull, 37...Runner, 38...Gate, 39 ...Lead frame escape recess, 40...Radiation plate escape recess, 41...Resin, 42...Printed wiring board, 43...Through hole, 44...Conductor layer portion, 45... ...Solder mound.

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 resin insulating layer on the back surface of the tab. 1. A semiconductor device comprising: a heat dissipation plate positioned close to each other through a portion thereof; and a package for sealing a semiconductor pellet, a tab, a part of the lead group, and a part of the heat dissipation plate with resin, 1. A semiconductor device characterized in that a heat dissipation plate is provided with an insulating gap adjusting section that controls the thickness of the resin insulating layer section by adjusting a gap with the tab. 2. The semiconductor device according to claim 1, wherein the gap adjustment portion is formed by protruding a part of the heat sink from one main surface toward the other main surface. 3. The semiconductor device according to claim 1, wherein the gap adjustment section is formed of an insulator attached to a heat sink. 4. A step in which a gap adjustment part is formed on one main surface of the heat sink, and a step in which a semiconductor pellet is bonded onto the tab of the lead frame, and the semiconductor pellet and the lead of the lead frame are electrically connected. and, with the heat sink and the lead frame in contact with each other with the gap adjustment portion interposed between the tab of the lead frame and the heat sink, the resin-sealed package is attached to a portion of the semiconductor pellet, the tab, and the lead. and a step of molding a part of the heat dissipation plate to be resin-sealed.