JPH1050912A - Semiconductor device, method of manufacturing the same, and lead frame used therein - Google Patents

Abstract

(57) [Problem] To lower a tab while suppressing an increase in the size of a resin sealing body. A power transistor includes a small outline package, a tab to which a pellet is bonded, an inner lead / tab suspension lead connected to the tab, and a first group outer lead connected to the tab suspension lead. 18, an inner lead 21 connected to the pellet by a wire 25, a second group outer lead 20 connected to the inner lead, a pellet, a combined tab suspension lead,
And a resin sealing body 27 for resin-sealing the inner lead and the wire. The first group outer leads 18 are lower than the second group outer leads 20 by the thickness of the pellet. [Effect] Since the tab is lowered outside the resin sealing body, there is no need to secure a tab lowering allowance inside the resin sealing body, the size of the resin sealing body can be reduced, and the same size resin sealing is performed. In the case of a stationary body, the size of the pellet that can be sealed with resin can be increased.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a technology for manufacturing a semiconductor device, and more particularly to a technology for manufacturing a semiconductor device having a resin-sealed package. Transistor).

[0002]

2. Description of the Related Art As a conventional power transistor of this type, a small outline package (hereinafter referred to as SO
It is called P. ).
That is, in the SOP, a plurality of outer leads are aligned and protruded from a pair of long sides in a rectangular flat resin molded body in which a semiconductor pellet (hereinafter, referred to as a pellet) is resin-sealed. Each outer lead is bent in a gull wing shape. The pellet is bonded to a tab inside the resin sealing body, and the tab is connected to a group of outer leads arranged on one side via a tab suspension lead also serving as an inner lead. Also, a plurality of inner leads are electrically connected to the pellet via wires, and each inner lead is connected to an outer lead group arranged on the other side.

Generally, in a power transistor having an SOP, a so-called tab lowering is carried out in order to bridge a wire for electrically connecting a pellet and an inner lead to a short distance and a low loop. That is, by bending the tab suspension lead inside the resin sealing body and lowering the tab by the thickness of the pellet, the wire bonding surface of the pellet coincides with the wire bonding surface of the inner lead, and the wire is short-distanced. In addition, a structure that bridges into a low loop is employed.

[0004] As an example describing the SOP, see "VLSI," published on May 31, 1993 by Nikkei BP Co., Ltd.
Packaging technology (above) "P80 to P84.

[0005]

However, in a power transistor having an SOP adopting the above-mentioned tab lowering, a tab lowering margin is required inside the resin sealing body. The SOP gets bigger,
In addition, the present inventor has clarified that when the size of the pellet is increased, the SOP cannot be mounted unless the size of the SOP is increased.

An object of the present invention is to provide a technique for manufacturing a semiconductor device capable of lowering a tab while suppressing an increase in the size of a resin sealing body.

[0007] 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.

[0008]

The outline of a typical invention among the inventions disclosed in the present application is as follows.

That is, in the semiconductor device manufacturing technique, the tab is lowered outside the resin sealing body.

Since the tab lowering is performed outside the resin sealing body, it is not necessary to secure a tab lowering allowance inside the resin sealing body, so that the size of the resin sealing body is reduced accordingly. Can be.

[0011]

FIG. 1 shows a power transistor including an SOP according to an embodiment of the present invention.
(A) is a partial cut-away plan view, and (b) is a side sectional view taken along line bb of (a). FIG. 2 and subsequent figures are diagrams for explaining each step of the method for manufacturing a power transistor having an SOP according to an embodiment of the present invention.

In the present embodiment, the semiconductor device according to the present invention is configured as shown in FIG. 1 as a power transistor having an SOP. The power transistor 28 includes a pellet 24 in which a power transistor element (not shown) is formed, a tab 15 to which the pellet 24 is bonded, and a plurality of inner leads electrically and mechanically connected to the tab 15. Tab hanging leads 19, outer leads 18 as a first group integrally connected to each of the dual-purpose tab hanging leads 19, and a plurality of inner leads electrically connected to the pellets 24 via wires 25. Lead 21 and each inner lead 21
The outer lead 20 as a second group, the pellet 24, and the common tab suspension lead 1 which are integrally connected to the
9, an inner lead 21, and a rectangular flat disk-shaped resin sealing body 27 for resin-sealing the wire 25. The first group of outer leads 18 protrudes from one long side of the resin sealing body 27 and is bent and formed into a gull wing shape, and the second group of outer leads 20 protrudes from the other long side and forms gull wings. It is bent into a shape. The first group of outer leads 18 is arranged at a position lower than the second group of outer leads 20 by the thickness of the pellet 24.

Hereinafter, a method of manufacturing a power transistor having an SOP according to an embodiment of the present invention will be described.
This description clarifies the details of the configuration of the power transistor including the SOP.

In the method of manufacturing a power transistor having the SOP, a multiple lead frame according to an embodiment of the present invention shown in FIG. 2 is used. The multiple lead frame 11 shown in FIG. 2 uses a plate material having good conductivity such as an iron-based material such as 42 alloy or a copper-based material (copper or copper alloy) such as oxygen-free copper. It is integrally formed into a rectangular thin plate shape by processing. The multiple lead frame 11 is configured by connecting a plurality of unit lead frames 12 in a single row. However, in the following description and drawings, only one unit is shown in principle.

The unit lead frame 12 has an outer frame (frame) 13.
a, the bottom rail 13b, the first side rail 13c, and the second side rail 13d are integrally assembled in a rectangular frame shape. Positioning holes 13e are formed in the top rail 13a and the bottom rail 13b, respectively. A pair of dedicated tab suspension leads 14, 14 are respectively provided on the first side rail 13c and the second side rail 13d so as to project inward at right angles, and a rectangular flat plate is provided between the two dedicated tab suspension leads 14, 14. A tab 15 formed in a shape is suspended. Tab 15 is pellet 2
It is formed in a rectangle larger by a predetermined size than 4.

Between the first side rail 13c and the second side rail 13d, a first tie bar 16 and a second tie bar 17 are provided on the top rail 13a side and the bottom rail 13b.
The tabs 15 are arranged in parallel with the tabs 15, respectively. Four outer leads 18 as a first group (hereinafter, referred to as a first group outer lead) 18 are arranged at equal intervals in the length direction and protrude in the right-angle direction at the end of the first tie bar 16 on the top rail 13a side. And each first group outer lead 18
Is integrally connected to the top rail 13a. A tab suspension lead (hereinafter, also referred to as a dual-purpose lead) 1 serving as an inner lead is provided at the opposite end of the first tie bar 16.
Four 9 are protruded from each of the first group outer leads 18 so as to be opposed to each other and integrated with each other. The tips of the dual-purpose leads 19 are integrally connected to the tabs 15. The portion of the first tie bar 16 between the adjacent first group outer leads 18 constitutes a dam 16a for damping outflow of the resin in a resin sealing body molding step described later.

Four outer leads 20 as a second group (hereinafter, referred to as a second group outer lead) 20 are arranged at equal intervals in the length direction on the bottom rail 13b side end side of the second tie bar 17, and are arranged at right angles to each other. The second group of outer leads 20 is integrally connected to the bottom rail 13b. Four inner leads 21 are provided at opposite ends of the second tie bar 17 so as to be opposed to the second group outer leads 20 so as to be integrally continuous with each other, and the tip of each inner lead 21 is a tab. 15 so as to be electrically insulated therefrom. The portion between the adjacent second group outer leads 20 in the second tie bar 17 is
Dams 17a for damping outflow of the resin in a resin sealing body molding step described later are respectively formed.

The first side rail 13c and the second side rail 13d have a pair of bent portions 22 for tab lowering,
Numerals 22 are arranged in the vicinity of the second tie bar 17 and formed so as to have a crank shape. Thus, the outer frame 13 is in a state where the top rail 13a side is lower than the bottom rail 13b side with respect to the line connecting the both bent portions 22 and 22 as a boundary. As a result, the dedicated tab suspension lead 14, tab 15 and first group outer lead 18 protruding from the top rail 13a are connected to the inner lead 21 group and the second group outer lead 2 suspended from the bottom rail 13b.
0 is lower than the plane constituted by 0 by the thickness of the pellet 24.

In the pellet bonding step, the pellets 24 are formed on the tabs 15 via the bonding portions 23 in the unit lead frames 12 configured as described above.
Are bonded as shown in FIG. Pellet 2
Reference numeral 4 shows a so-called pre-process in a manufacturing process of a semiconductor device, in which a MOS power transistor element is built. The bonding part 23 is made of solder or silver (Ag) paste,
It is formed from a gold-silicon eutectic layer or the like. In this state, the pellet 24 includes the tab 15 and the dual-purpose lead 19.
Are electrically connected to the first group outer leads 18 via the first group, and the drains of the pellets 24 are electrically drawn out to the first group outer leads 18.

In the wire bonding step, each wire 25 is placed between each electrode pad 24a of the pellet 24 and each inner lead 21 in the unit lead frame 12 having the pellet 24 bonded to the tab 15 in this manner.
Are bridged as shown in FIG. At this time, since the tab 15 is lower than the inner lead 21 by the thickness of the pellet 24, the wire 25 is in a state of being bridged into a short distance and a low loop. The gate and the source of the power transistor element formed in the pellet 24 include the respective electrode pads 24a, the respective wires 25, the respective inner leads 21 and the second group outer leads 2 of the pellet 24.
0, it is in a state of being electrically drawn to the outside.

In the assembly 26 shown in FIG. 3 configured as described above, the transfer molding apparatus 30 shown in FIG.
The resin sealing body 27 is formed as shown in FIG.

The transfer molding apparatus 30 shown in FIG. 4 includes an upper mold 31 and a lower mold 32 which are clamped by a cylinder device (not shown).
The upper mold cavity recess 3
A plurality of sets 3a and lower cavity recesses 33b are respectively provided so as to form the cavities 33 in cooperation with each other. Each cavity 33 has a so-called through mold structure in which the adjacent cavities 33, 33 are sequentially filled with resin. However, in the following description and illustration, only one unit is shown in principle.

A pot 34 is opened on the mating surface of the lower mold 32, and the pot 34 has a cylinder device (not shown).
The plunger 35 which is moved forward and backward is inserted so that the resin can be fed. On the mating surface of the other upper mold 31, a cull 36 is disposed at a position facing the pot 34 and is submerged, and a runner 37 is submerged so as to be connected to the pot 34. The other end of the runner 37 is connected to the upper cavity recess 33a, and a gate 38 is formed at the connection so that the resin can be injected into the cavity 33. At a position facing the gate 38 in the upper cavity recess 33a, a through gate 39 is buried, and the through gate 39 is connected to the adjacent upper cavity recess 33a.

A step is formed at a position corresponding to the two bent portions 22 of the outer frame 13 on the mating surface of the upper die 31 and the lower die 32, and a step is formed between the line connecting the outer frame 13 and the two bent portions 22. It is formed so that the top rail 13a side is lower than the bottom rail 13b side.

At the time of transfer molding, the assembly 26 according to the above-described configuration is configured such that the multiple lead frames 11 are placed on the lower mold 32 and the tabs 15 of the unit lead frames 13 are formed.
The group of inner leads 21 and the group of wires 25 are accommodated in the lower cavity recess 33b. In this state, the portion of the outer frame 13 on the top rail 13a side is placed on the lower step portion 40a of the step in the lower die 32, and the portion on the bottom rail 13b side is the upper step portion 40b of the step in the lower die 32. It will be in a state of being placed on. When the top rail 1 is housed in the lower cavity recess 33b,
The tab 15 hung on the 3a side is lower than the plane formed by the inner lead 21 group and the second group outer lead 20 group hung on the bottom rail 13b by the thickness of the pellet 24. I have.

Subsequently, when the upper die 31 and the lower die 32 are clamped, the outer frame 13, the first group of outer leads 18 and the second group of outer leads 20 of each unit lead frame 12 are connected to the upper die 31 and the lower die 31. The tab 15 of each unit lead frame 13, the group of inner leads 21 and the group of wires 25 are housed in the cavity 33 while being sandwiched between the mating surfaces with the mold 32. In the state accommodated in the cavity 33, the group of wires 25 is the pellet 24 located on the same plane.
And each inner lead 21 is bridged by a short distance and a low loop, so that it is sufficiently separated from the ceiling surface of the upper cavity recess 33a.

Thereafter, the resin 41 is fed from the pot 34 by the plunger 35 to the cavity 33 through the runner 37, the gate 38 or the through gate 39, and injected. After the injection, when the resin 41 is thermally cured to form the resin sealing body 27, the upper mold 31 and the lower mold 32 are opened, and the resin sealing body 27 is separated by an ejector pin (not shown). Typed.

As shown in FIG. 5, the inside of the resin molded body 27 molded as described above contains pellets 24, tabs 15, inner leads 21 and wires 25.
Group, part of dedicated tab suspension lead 14 and dual-purpose lead 1
The ninth group is in a resin-sealed state, and a part of the first group outer lead 18, the second group outer lead 20, and a part of the dedicated tab suspending lead 14 project from the resin sealing body 27 to the outside. In this state, the first group outer lead 18,
The plane formed by the dedicated tab suspension lead 14 and the top rail 13a side portion of the outer frame 13 is the second group outer lead 2
0 and the outer frame 13 are lower than the plane formed by the bottom rail 13b side by the thickness of the pellet 24. Further, inside the resin sealing body 27, the group of wires 25 cross-linked into a low loop is in a state of keeping a sufficient distance from the upper surface of the resin sealing body 27.

After the resin sealing body 27 is formed, the multiple lead frame 11 is subjected to the outer frame 13, the dams 16a of the first tie bar 16 and the dams of the second tie bar 17 in a lead cutting and forming step (not shown). 17a is cut off, and the first group of outer leads 18 and the second group of outer leads 20 are each bent and formed into a gull-wing shape. Thus, the power transistor 28 including the SOP shown in FIG. 1 is manufactured.

According to the above embodiment, the following effects can be obtained. In the method for manufacturing a power transistor having an SOP, by performing tab lowering outside the resin sealing body, it is not necessary to secure a tab lowering allowance inside the resin sealing body. The size of the body can be reduced, and in the case of resin-sealed bodies of the same size, the size of pellets that can be resin-sealed can be set large.

By securing the tab lowering, the wire bonding surface of the pellet and the wire bonding of the inner lead can be matched, so that the wire is bridged into a short distance and a low loop while separating the wire from the pellet and the inner lead. be able to.

According to the above, the insulation performance of the wire against the pellet and the inner lead can be ensured, and the apex of the wire loop can be sufficiently separated from the upper surface of the resin sealing body. The insulation performance of the wire can be improved.

FIGS. 6A and 6B show a power transistor having an SOP according to a second embodiment of the present invention. FIG. 6A is a partially cutaway plan view, and FIG. 6B is a sectional view taken along line bb of FIG. It is a side sectional view.

The second embodiment differs from the first embodiment in that the dedicated tab suspension lead is omitted. In the second embodiment, the tab 15 to which the pellet 24 is bonded is suspended by the dual-purpose lead 19,
Since the first group outer lead 18 connected to the dual-purpose lead 19 is lower than the second group outer lead 20, the same effect as in the first embodiment can be obtained.

FIGS. 7A and 7B show a semiconductor integrated circuit device having an SOP according to a third embodiment of the present invention. FIG. 7A is a partially cutaway plan view, and FIG. 7B is a partially cutaway side view.

The third embodiment is different from the first embodiment in that a semiconductor device having an SOP is a power semiconductor integrated circuit device (hereinafter referred to as a power SOP IC) 28A.
And the dual-purpose lead is configured as a dedicated inner lead 19 </ b> A and is electrically connected to the pellet 24 via a wire 25. In this power SOP IC, the first group outer lead 1
8 and the second group outer lead 20 are located in the same plane, and the cutting traces of the pair of dedicated tab suspension leads 14, 14 are pellets with respect to the plane including the first group outer lead 18 and the second group outer lead 20. It is shifted in the thickness direction of the resin sealing body 27 by the thickness of 24.

In the third embodiment, the tab 15 to which the pellet 24 has been bonded is suspended only by the pair of dedicated tab suspension leads 14, 14. Since it is lower than the first group outer leads 18 and the second group outer leads 20 outside, the same effect as in the first embodiment can be obtained.

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 gist of the invention. Needless to say.

For example, the mating surface of the upper mold and the lower mold in the molding apparatus is not limited to being formed parallel to the plane of the tab, but may be the first mold.
It may be formed on an inclined surface including a line connecting the group outer lead and the second group outer lead.

The number of outer leads is not limited to eight,
The number of dedicated tab suspension leads is not limited to two, and the number of combined leads is not limited to four.

In the above description, the invention made mainly by the present inventor is based on the SOP, which is the field of application behind the invention.
Power transistor and power SOP
The description has been given of the case where the present invention is applied to an IC. However, the present invention is not limited to this, and is not limited to a normal SOP IC or a transistor array. The present invention can be applied to all semiconductor devices having a resin-sealed package such as a single outline package. Especially,
INDUSTRIAL APPLICABILITY The present invention is applicable to a semiconductor device manufacturing technique in which a large-sized pellet is resin-sealed by a small resin-sealed body, and excellent effects can be obtained.

[0042]

The effects obtained by typical aspects of the invention disclosed in the present application will be briefly described as follows.

In the manufacture of a semiconductor device having a resin-sealed package, the tab is lowered outside the resin-sealed body, so that there is no need to secure a tab-down allowance inside the resin-sealed body. Accordingly, the size of the resin sealing body can be reduced, and in the case of the same size of the resin sealing body, the size of the resin sealable pellet can be set large.

[Brief description of the drawings]

1A and 1B show a power transistor including an SOP according to an embodiment of the present invention, in which FIG. 1A is a partially cutaway plan view, and FIG. 1B is a side cross-sectional view taken along line bb of FIG. FIG.

FIG. 2 shows a multiple lead frame used in a method of manufacturing a power transistor having an SOP according to an embodiment of the present invention, wherein (a) is a partially omitted plan view,
(B) is a cross-sectional end view taken along arrow bb in (a), (c) is a cross-sectional end view taken along arrow c-c in (a), and (d) is a partially omitted front view.

FIG. 3 is an enlarged plan view showing a state after a pellet bonding step and a wire bonding step in a method of manufacturing a power transistor having an SOP according to an embodiment of the present invention, and FIG. (B) is a cross-sectional view taken along the line bb in (a).

FIG. 4 also shows a resin sealing body molding step,
(A) is a partially omitted front sectional view, and (b) is bb in (a).
It is a side sectional view along a line.

FIG. 5 also shows a state after the resin sealing body molding step;
(A) is a partially cutaway plan view with a part omitted, and (b) is b in (a).
-B arrow sectional view, (c) is cc arrow sectional view of (a),
(D) is a partially omitted front view partially omitted.

6A and 6B show a power transistor including an SOP according to a second embodiment of the present invention, in which FIG. 6A is a partially cut-away plan view, and FIG. 6B is a side sectional view taken along line bb of FIG. FIG.

7A and 7B show a semiconductor integrated circuit device including an SOP according to a second embodiment of the present invention, wherein FIG. 7A is a partially cut-away plan view, and FIG. 7B is a partially cut-away side view.

[Description of sign]

11: multiple lead frame, 12: unit lead frame, 13: outer frame (frame), 13a: top rail,
13b: bottom rail, 13c: first side rail, 1
3d: second side rail, 13e: positioning hole, 14:
Dedicated tab suspension lead, 15 ... tab, 16 ... first tie bar, 16a ... dam, 17 ... second tie bar, 17a ... dam, 18 ... first group outer lead, 19 ... inner lead / tab suspension lead (shared lead), 20 ... Second group outer lead, 21 ... Inner lead, 22 ... Bent part, 23 ... Bonding part, 24 ... Pellet (semiconductor pellet), 2
4a: electrode pad, 25: wire, 26: assembly, 27
... resin sealing body, 28 ... power transistor (semiconductor device) provided with SOP, 30 ... transfer molding device,
31 upper mold, 32 lower mold, 33 cavity, 33a
... Upper cavity recess, 33b Lower cavity recess, 34 Pot, 35 plunger, 36 Cal, 3
7 ... runner, 38 ... gate, 39 ... through gate, 40
a: Lower part, 40b: Upper part, 41: Resin, 19A ...
Dedicated inner lead, 28A Power SOP IC (semiconductor device).

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Kuniharu Muto Inventor, 15 Asahidai, Moroyama-cho, Iruma-gun, Saitama

Claims (7)

[Claims] 1. A semiconductor device in which a plurality of outer leads are aligned and protruded in at least one side from at least one side in a rectangular flat resin molded body in which semiconductor pellets are molded with a resin. Wherein the lead for suspending the tab to which the semiconductor pellet is bonded is shifted from the outer lead group in the thickness direction of the resin sealing body. 2. A lead for suspending the tab is connected to the outer lead group and another outer lead, and the other outer lead group is connected to a side on which the outer lead group is arranged among four sides of the resin sealing body. The semiconductor device according to claim 1, wherein the semiconductor device is arranged on another side. 3. A lead for suspending the tab is a dedicated tab suspending lead, and the tab suspending lead is disposed on a side different from a side on which the outer lead group is disposed among four sides of the resin sealing body. 2. The semiconductor device according to claim 1, wherein a cutting mark of the tab suspension lead is shifted in a thickness direction of the resin sealing body with respect to the outer lead group. 4. The method of manufacturing a semiconductor device according to claim 1, wherein the outer lead group is provided on at least one side of a rectangular frame-shaped outer frame, and a lead for suspending the tab is provided outside. The lead protruding from the other side of the frame, the outside of the molding area of the resin sealing body is bent, and the lead for suspending this tab is arranged in the thickness direction of the resin sealing body with respect to the outer lead group. A lead frame forming step in which the shifted lead frame is formed; a bonding step in which the semiconductor pellet is bonded to the tub; and a connection step in which the semiconductor pellet is electrically connected to the outer lead group; A lead frame is sandwiched between mating surfaces of an upper mold and a lower mold of a molding die, and the tab is accommodated in a cavity formed in the mating surface. A resin-sealed body molding step in which a resin is filled in a tee to form the resin-sealed body. 5. A lead frame used in the method for manufacturing a semiconductor device according to claim 4, wherein the outer lead group is provided so as to project from at least one side of a rectangular frame-shaped outer frame, and the tab is formed. A lead to be suspended protrudes from the other side of the outer frame, and the outside of the molding area of the resin sealing body is bent, so that the lead for suspending the tab is formed by the resin sealing with respect to the outer lead group. A lead frame, which is displaced in a thickness direction of a body. 6. A lead for suspending the tab is connected to the outer lead group and another outer lead, and the other outer lead group is different from a side of the outer frame on which the outer lead group is arranged. The lead frame according to claim 5, wherein the lead frame is arranged on a side. 7. The tab suspension lead is a dedicated tab suspension lead, and the tab suspension lead is disposed on a side different from the side on which the outer lead group is disposed among the four sides of the outer frame. 6. The lead frame according to claim 5, wherein the tab suspension leads are shifted from the outer lead group in the thickness direction of the resin sealing body.