JP2001035987A - Semiconductor device and manufacture thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To set a space between the fringe of a resin sealing body and a pellet narrow by contracting the pitch of the drawing-around pat of adjacent inner leads, and to avoid increase of the line width of the resin sealing body, even when the number of pins increases or the size of the pellet is enlarged, and to increase the number of pins when the sizes of the resin sealing body and the pellet are under the same conditions. SOLUTION: In an SOP IC, which is equipped with tabs 6 bonded to an oblong semiconductor pellet 22, a plurality of inner leads 8A and 8B arranged outside both long sides of the tabs 6, a group of wires 23 bridged between the inner leads and a pellet 2, each other lead 7A and 7B coupled with each inner lead 8A and 8B, and a resin sealing body 24, the laying-around parts 10A and 10B for each inner lead are shifted in the thickness direction, thereby setting the pitch between the fellow neighbors small.

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 using a lead frame. For example, the present invention relates to a small outline package (hereinafter referred to as an SOP) and a dual in-line. The present invention relates to a device which is effective when used in a semiconductor integrated circuit device (hereinafter, referred to as IC) having a package (hereinafter, referred to as DIP).

[0002]

2. Description of the Related Art SOPs and DIPs are widely used as IC packages such as memories because outer leads are arranged in a row on a pair of side surfaces of a resin sealing body.
For example, an IC having an SOP (hereinafter referred to as an SOP IC
That. ) Is a semiconductor pellet (hereinafter, referred to as a pellet) in which an integrated circuit including a memory is built, a tab to which the pellet is bonded, a plurality of inner leads wired around the tab, and a plurality of inner leads. A group of wires bridged between the lead and the pellet,
It has a plurality of outer leads integrally connected to each inner lead, and a resin sealing body in which the pellets, the inner lead group and the wire group are resin-sealed, and the resin sealing body has a rectangular flat plate shape. The outer lead group is arranged on each of two long side surfaces and bent in a gull wing shape.

[0003] Examples of SOP and DIP are described in "Practical Course VLSI Packaging Technology (above)" P80 to P8 issued on May 31, 1993 by Nikkei BP.
There are four.

[0004]

In SOP and DIP, the outer leads are arranged on the long side of the resin sealing body, so that the inner leads are also narrow on the long side inside the resin sealing. The layout is concentrated on the area. Therefore, when the number of outer leads is increased or the size of the pellet is increased, the routing area of the inner lead group inside the resin sealing body becomes insufficient. In order to solve the shortage of the routing area, the lateral width (dimension of the short side) of the resin sealing body is increased, so that the lateral width of the SOP or DIP is increased, and the SO
In some cases, it is not possible to comply with the P and DIP standards.

An object of the present invention is to provide a semiconductor device manufacturing technique capable of coping with an increase in the number of pins and an increase in the size of a semiconductor pellet while preventing an increase in the width of a package.

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.

[0007]

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

That is, a semiconductor pellet, a tab to which the semiconductor pellet is bonded, a plurality of inner leads wired around the tab, and a bridge between the inner lead and the semiconductor pellet. In a semiconductor device comprising: a wire group; a plurality of outer leads connected to the respective inner leads; and a resin sealing body in which the semiconductor pellet, the inner lead group, and the wire group are resin-sealed. The wiring part of each inner lead is shifted in the thickness direction, and the pitch between adjacent leads is set to be small.

According to the above-described means, the lead portion of each inner lead is shifted in the thickness direction so that the pitch between the adjacent leads is set to be small. Therefore, even when the number of outer lead groups increases or the size of the semiconductor pellet increases, it is possible to avoid an increase in the width of the resin sealing body.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows an SOP IC according to an embodiment of the present invention.
(B) is a front sectional view. FIG. 2 is an explanatory view showing a method for manufacturing an SOP / IC according to an embodiment of the present invention.

In the present embodiment, the semiconductor device according to the present invention is configured as an SOP IC 26. SO
The P-IC 26 includes a pellet 22 formed in a rectangular flat plate shape, and upper inner leads 8A in the upper plane and lower inner leads 8B in the lower plane, which are wired outside both long sides of the pellet 22, respectively. And each inner lead 8
A, 8B and a wire 23 group respectively bridged between the pellet 22, an outer lead 7A, 7B group integrally connected to each inner lead 8A, 8B, and a pellet 22, the inner lead 8A, 8B. And a resin sealing body 24 for resin-sealing the group and the group of wires 23.

The leading portion 10A of the upper inner lead 8A and the leading portion 10B of the lower inner lead 8B are alternately shifted vertically to be insulated from each other. The bonding pad 9A at the distal end of the upper inner lead 8A and the bonding pad 9B at the distal end of the lower inner lead 8B are alternately shifted vertically and aligned in the circumferential direction. .

On the other hand, each of the outer leads 7A and 7B is formed in a gull wing shape by projecting at right angles in the same plane from two long sides of the resin sealing body 24 in the same plane. The mounting surface formed on the lower surface at the outermost end of the gull wing shape of each of the outer leads 7A and 7B is formed so as to be slightly lower than the lower surface of the resin sealing body 24.

Then, the SOP IC 26 according to the above configuration
Is manufactured by the following manufacturing method.

Hereinafter, an embodiment of the present invention will be described.
A method for manufacturing an IC will be described. By this description, the details of the configuration of the SOP IC 26 will be clarified.

The method of manufacturing the SOP IC is shown in FIG. 4 in which the upper multiple lead frame 1A shown in FIG. 2 and the lower multiple lead frame 1B shown in FIG. 3 are stacked. Is used. In the multiple lead frames, each unit lead frame is continuous in one direction, but for convenience, a unit lead frame that is one unit will be described and illustrated. Also, only half of one unit is shown in the plan view.

The upper multiple lead frame 1A and the lower multiple lead frame 1B constituting the laminated multiple lead frame 1 shown in FIG. 4 have the same components except for a tab, Each is formed in substantially the same shape. Therefore, first, the components of the lower multiple lead frame 1B shown in FIG. 3 will be described.

The lower multiple lead frame 1B includes a plurality of lower unit lead frames (hereinafter, referred to as lower lead frames) 2B which are connected in one direction (hereinafter, referred to as left and right direction). The lower lead frame 2B is a pair of outer frames 3B, 3B before and after being arranged in parallel at a predetermined interval (however, only the rear outer frame is shown in FIG. 3; other components. The outer frames 3B and 3B are connected to each other by adjacent lower lead frames 2B and 2B. Between the outer frames 3B and 3B, a pair of left and right section frames 4B,
4B, and a rectangular frame (frame) is formed by both outer frames 3B, 3B and both section frames 4B, 4B. In the center between both section frames 4B, 4B in both outer frames 3B, 3B, a pair of tab suspension leads 5B,
5B are projected at right angles, and a tab 6 having a rectangular flat plate shape is suspended between both tab suspension leads 5B and 5B. The tab 6 has an upper surface lower than a plane including the frame by bending both tab suspension leads 5B and 5B into a crank shape. This is a so-called tab lowering.

In the section frame 4B, a plurality of outer leads 7B are provided at right angles to the section frame 4B and arranged at equal intervals. An inner lead 8B is integrally connected to each outer lead 7B so as to be continuous with the inner tip. The tip of each inner lead 8B is a tab 6
The bonding pad 9 </ b> B is constituted by the front end of the bonding pad 9 </ b> B. The pitch between the adjacent bonding pad portions 9B, 9B is smaller than the pitch between the outer leads 7B, 7B which are continuous with these.

On the other hand, no tab is formed on the upper unit lead frame (hereinafter, referred to as the upper lead frame) 2A of the upper multiple lead frame 1A shown in FIG. In addition, the lead portion 10A of each upper inner lead 8A in the upper lead frame 2A is bent upward in the thickness direction into a crank shape, and is laid slightly above the upper surface of the lead portion 10B of the lower inner lead 8B. It is in a state of being left. Then, as shown in FIG. 4, the upper lead frame 2A is arranged concentrically on the lower lead frame 2B, and the upper outer frame 3A and the upper section frame 4A are connected to the lower outer frame 3B and the lower side. It is superposed and fixed on the section frame 4B. Thus, a laminated unit lead frame (hereinafter, referred to as a laminated lead frame) 2 is manufactured.

In the laminated lead frame 2, the routing portion 10 of the upper inner lead 8A of the upper lead frame 2A
Since A is bent upward in the thickness direction into an L-shape,
As shown in FIG. 4A, the middle portion and the tip portion are located above the routing portion 10B of the inner lead 8B of the lower lead frame 2B.
Also, as shown in FIG. 4A, the pitch P in the left-right direction between the routing portion 10A of the upper inner lead 8A and the routing portion 10B of the lower inner lead 8B is set to be extremely small. Further, the bonding pad portion 9A at the tip of the upper inner lead 8A is located between the adjacent lower bonding pad portions 9B and 9B, and is shifted vertically.

Pellet bonding and wire bonding are performed on the laminated lead frame 2 having the above configuration in the pellet bonding step and the wire bonding step, and the assembly 20 shown in FIG. 5 is manufactured.

First, in a pellet bonding step, in a so-called pre-process of a semiconductor, an integrated circuit including a semiconductor element such as a memory is formed, and a pellet 22 formed into a rectangular flat plate shape is formed on a tab 6 of the lower lead frame 2B. It is concentrically disposed on the top and bonded and bonded by a bonding layer 21 formed of silver paste or the like.

Next, in the wire bonding step, each wire 23 is moved between each of the inner leads 8A and 8B of the upper lead frame 2A and the lower lead frame 2B of the laminated lead frame 2 and the pellet 22.
Both ends are bonded to the bonding pad 9A of the upper inner lead 8A, the bonding pad 9B of the lower inner lead 8B, and the electrode pad of the pellet 22, respectively, to form a bridge. This wire bonding operation may be performed by either a nail head bonding method or a wedge bonding method.

Incidentally, it is more efficient to perform the wire bonding operation for each inner lead 8A group of the upper lead frame 2A and each inner lead 8B of the lower lead frame 2B. This is because the work efficiency is better when the wire bonding operation is performed on the same plane than when the upper and lower two steps are performed alternately.

By the above-described pellet bonding operation and wire bonding operation, the integrated circuit formed in the pellet 22 is electrically supplied to the outside via the electrode pad, the wire 23, the inner lead 8A and the outer lead 7A, the inner lead 8B and the outer lead 7B. It will be in a state that is derived.

Thereafter, as shown in FIG. 6, a resin sealing body 24 is
Is used to perform resin molding, and the molded article 25 shown in FIG. 7 is molded.

The transfer molding apparatus 30 includes a pair of upper mold 31 and lower mold 32 which are clamped to each other by a cylinder device or the like (not shown). A plurality of sets of the upper mold cavity recessed portion 33a and the lower mold cavity recessed portion 33b are provided so as to form the cavity 33 in cooperation with each other.
On the mating surface of the upper mold 31, a pot 34 is opened,
A plunger 35 advanced and retracted by a cylinder device (not shown) is attached to the pot 34 by a resin (hereinafter, referred to as a molding material).
It is called resin. ).

A cull 36 is disposed on the mating surface of the lower mold 32 at a position facing the pot 34 and is sunk.
Runners 37 are arranged radially so as to be connected to the pot 34 and are submerged. The other end of each runner 37 is connected to one corner of the lower cavity recess 33b, and a gate 38 is formed at the connection so that the resin can be injected into the cavity 33. . A plurality of dam blocks 39 are provided on the long side of the lower cavity recess 33b on the mating surface of the lower die 32, and
The outer leads 7A and 7B are provided so as to correspond to the respective outer leads 7A and 7B.

Next, the operation of transfer molding the resin sealing body 24 using the laminated lead frame 2 according to the above configuration will be described. When the resin sealing body 24 is subjected to transfer molding, the laminated lead frame 2 is placed on the lower die 32 such that the outer leads 7A, 7B are fitted between the adjacent dam blocks 39, 39, and the pellet 22 is formed. Are arranged and set so as to be accommodated in each cavity 33. Subsequently, the upper mold 31 and the lower mold 32 are clamped.

Thereafter, the resin 40 is fed from the pot 34 to the cavity 33 through the runner 37 and the gate 38 by the plunger 35 and is filled. At this time,
The resin 40 filled in the cavity 33 is
Outer lead 7 on the mating surface of the lower die 32
It tries to leak out of the cavity 33 from the gap between A and 7B. However, the adjacent outer leads 7A and 7A
Since the dam block 39 is inserted between the first and second blocks B,
The resin 40 filled in the cavity 33 is prevented from leaking outside through the gap between the outer leads 7A and 7B.

Thereafter, the upper mold 31 and the lower mold 32 are opened, and the resin sealing body 24 is released from the cavity 33 by an ejector pin (not shown).
Then, the laminated lead frame 2 in which the resin sealing body 24 has been molded is detached from the transfer molding device 30.

As shown in FIG. 7, inside the resin molded body 24 formed in this manner, the tab 6,
The pellet 22, the upper inner lead 8A, the lower inner lead 8B, and the group of wires 23 are sealed with resin. In this state, the lower surface of the leading portion 10A of the upper inner lead 8A and the upper surface of the leading portion 10B of the lower inner lead are slightly displaced from each other in the horizontal direction, and the resin of the resin seal 24 is filled in the upper and lower gaps. Since it is in a filled state, it is in an electrically insulated state.

The molded product 25 on which the resin sealing body 24 is molded as described above is cut off the outer frame in the lead cutting and molding step, and each outer lead 7A, 7B is bent and formed into a gull-wing shape. Thus, the SOP IC 26 according to the above configuration is manufactured.

SOP IC manufactured as described above
26 is to be surface-mounted on a printed wiring board.
At this time, the package specification satisfies the standard of the conventional SOP / IC, so that the surface mounting form is the same as the conventional one.

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

1) Since the pitch of the adjacent inner leads can be reduced by vertically moving the adjacent inner leads, the distance between the outer edge of the resin sealing body and the pellet can be reduced. The space can be set narrow.

2) According to the above 1), even when the number of outer leads is increased or the size of the pellet is increased, it is possible to avoid an increase in the lateral width of the resin sealing body.

3) When the size of the resin sealing body and the size of the pellet are the same, the number of outer leads can be increased.

4) Even though the inner leads are arranged in a two-stage configuration, the SOP specification can maintain the conventional standard. It is not necessary to impair the rules and the work efficiency of the mounting work and the like.

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

For example, the bonding pad 9A of the upper inner lead 8A and the bonding pad 9B of the lower inner lead 8B are not limited to being vertically shifted.
As shown in FIG. 8, they may be aligned on the same plane.

The group of inner leads and outer leads is not limited to being formed by a laminated lead frame, but may be formed by a single lead frame.

Each outer lead is not limited to being formed into a gull wing shape, but may be formed so as to correspond to DIP.

The present invention is not limited to the arrangement of the dam block in the transfer molding apparatus, but the arrangement may be such that a dam bar is arranged in the lead frame.

In the above description, the invention made mainly by the present inventor is based on the SOP which is
The case where the present invention is applied to an IC has been described. However, the present invention is not limited to this. The present invention can be applied to an IC having a resin-sealed package such as a DIP, and to semiconductor devices such as transistors in general. Further, the present invention is not limited to the memory IC, and can be applied to all semiconductor devices for other uses.

[0047]

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

By shifting the wiring portion of the adjacent inner lead up and down, the pitch of the wiring portion of the adjacent inner lead can be reduced, so that the space between the outer edge of the resin sealing body and the pellet is reduced. It can be set narrow. As a result, even if the number of outer leads increases or the size of the pellets increases, it is possible to avoid an increase in the width of the resin sealing body. When the size of the resin sealing body and the size of the pellet are the same, the number of outer leads can be increased.

[Brief description of the drawings]

FIGS. 1A and 1B show an SOP IC according to an embodiment of the present invention, in which FIG. 1A is a partially cut plan view, and FIG.

2A and 2B show an upper multiple lead frame used in a method of manufacturing an SOP / IC according to an embodiment of the present invention, wherein FIG. 2A is a partially omitted plan view, and FIG. bb
It is a front sectional view along a line.

FIG. 3 also shows a lower multiple lead frame,
(A) is a partially omitted plan view, and (b) is a front sectional view taken along line bb of (a).

FIG. 4 also shows a laminated multiple lead frame,
(A) is a partially omitted plan view, and (b) is a front sectional view taken along line bb of (a).

FIG. 5 shows a state after the wire bonding step in the SOP / IC manufacturing method according to one embodiment of the present invention;
(A) is a partially omitted plan view, and (b) is a front sectional view taken along line bb of (a).

FIG. 6 also shows a transfer molding step,
(A) is a side sectional view, and (b) is a sectional view along the bb line of (a).

7A and 7B show a state after transfer molding, in which FIG. 7A is a partially omitted plan view, and FIG. 7B is a front sectional view taken along the line bb of FIG.

8A and 8B show an SOP / IC according to another embodiment of the present invention, wherein FIG. 8A is a front sectional view, and FIG. 8B is a partially omitted perspective view.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Multilayer lead frame, 1A ... Upper multiple leadframe, 1B ... Lower multiple leadframe, 2 ... Multilayer leadframe (multilayer unit leadframe), 2A ... Upper leadframe (upper unit leadframe), 2B ... Lower lead frame (lower unit lead frame), 3A, 3
B: outer frame, 4A, 4B: section frame, 5A, 5B: tab suspension lead, 6: tab, 7A, 7B: outer lead,
8A, 8B: inner lead, 9A, 9B: bonding pad portion, 10A, 10B: routing portion, 20: assembly,
21: bonding layer, 22: pellet, 23: wire, 24: resin sealing body, 25: molded product, 26: SOP
IC (semiconductor device), 30 ... transfer molding device, 3
1 upper mold, 32 lower mold, 33 cavity, 34 pot, 35 plunger, 36 cal, 37 runner,
38: gate, 39: dam block, 40: resin.

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 5F067 AA01 AA09 AA10 AB02 BB00 BB02 DA05 DA07 DE05 DE14

Claims (10)

[Claims] 1. A semiconductor pellet, a tab to which the semiconductor pellet is bonded, a plurality of inner leads wired around the tab, and a bridge formed between each of the inner leads and the semiconductor pellet. In a semiconductor device comprising: a wire group; a plurality of outer leads connected to the respective inner leads; and a resin sealing body in which the semiconductor pellet, the inner lead group, and the wire group are resin-sealed. A semiconductor device, wherein the lead portions of each inner lead are shifted in the thickness direction so that the pitch between adjacent leads is set small. 2. The semiconductor device according to claim 1, wherein the bonding pads of the inner leads are shifted from each other in a thickness direction of the resin sealing body. 3. The semiconductor device according to claim 1, wherein the bonding pad portions of the respective inner leads are arranged on the same plane. 4. The inner lead group is disposed on both long side surfaces of the resin sealing body, and a lead portion of each inner lead of both inner lead group rows is formed in an L-shape. The semiconductor device according to claim 1, 2 or 3, wherein 5. A lead frame manufacturing process for manufacturing a lead frame in which a lead portion of each inner lead is shifted in a thickness direction and a pitch between adjacent inner leads is set small, and a semiconductor pellet is provided on a tab of the lead frame. A wire bonding step in which both ends of the wire are bonded to the electrode pads of the semiconductor pellet and the bonding pads of the inner leads of the lead frame; and the semiconductor pellet and the inner lead. A resin-sealed body forming step of forming a resin-sealed body for resin-sealing the group and the wire group, and a lead forming step in which an outer frame of the lead frame is cut off and the outer lead is bent. A method of manufacturing a semiconductor device. 6. The lead frame is a laminated lead frame in which an upper lead frame in an upper plane and a lower lead frame in a lower plane are vertically stacked, and routing of each inner lead of the upper lead frame. 6. The method for manufacturing a semiconductor device according to claim 5, wherein the lead portion and the lead portion of each inner lead of the lower lead frame are vertically stacked. 7. The method of manufacturing a semiconductor device according to claim 5, wherein bonding pad portions of the inner leads in the laminated lead frame are vertically shifted. 8. The method of manufacturing a semiconductor device according to claim 5, wherein bonding pad portions of said inner leads in said laminated lead frame are arranged on the same plane. 9. The semiconductor device according to claim 7, wherein in the wire bonding step, after the wire bonding is performed on the lower inner lead group, the wire bonding is performed on the upper inner lead group. Manufacturing method. 10. The method of manufacturing a semiconductor device according to claim 5, wherein a dam block is formed in a molding die in the resin sealing body molding step.