JPH0370165A - Bending method and forming device for external lead of resin sealed semiconductor device - Google Patents

Abstract

PURPOSE:To put it in the conditions that the tops of external leads are equal completely even if the resin sealed part shrinks or warps by bending external leads in the conditions of being coupled by a coupling piece, and then cutting off the coupling piece so that each external lead may be of the specified length. CONSTITUTION:Resin is removed from around the resin sealed part 14 or between external leads 16 of a semiconductor device 10 which is coupled to a lead frame 12 and is sealed with resin. Successively, the tops of the external leads 16 of the semiconductor device 10 are cut off in the conditions of being coupled with a coupling piece 20. And, the semiconductor device 10 is separated from the lead frame 12. Each external lead group 16g extended on two sides of the semiconductor device 10 are bent in Z shape. The coupling piece 20 at the tops of the external lead groups 16g of the semiconductor device 10 being bent is cut off.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a method and forming device for bending external leads of a resin-sealed semiconductor device.

(Prior Art) A conventional method for manufacturing a resin-sealed semiconductor device (hereinafter simply referred to as a semiconductor device) involves bonding a semiconductor chip to a stage portion of a lead frame, and performing wire bonding to perform resin sealing.

Then cut the dam bar.

Next, it was supported on the rail with a hanging bottle.

Each of the external leads of the semiconductor device was cut into laJ pieces so that the tips of the external leads were in a free state, the external leads were bent, and then the semiconductor device was separated from the rail.

In addition, when bending the external leads of a semiconductor device with the semiconductor device separated from the rail, separate the semiconductor device from the rail after resin sealing and transport the separated semiconductor device to each process. and then processed it.

(Problems to be Solved by the Invention) The above semiconductor device is mounted on a printed circuit board after molding, but
At this time, the tip of each external lead of the semiconductor device is
It is necessary to match the connection part of the board.

However, the synthetic resin sealed with resin to form the resin-sealed portion contracts as the temperature of the resin decreases. For example, FIG. 10 shows a semiconductor device in a contracted state, and in this figure, the size of the resin sealing portion 2 before shrinkage is indicated by a two-dot chain line.

Due to such contraction of the resin sealing part 2, the entire resin sealing part 2 is warped. This is because a stress difference is generated between the upper and lower parts of the resin sealing part 2 (see Fig. 11).
. Further, while the distance between the bases of the external leads 3 arranged in parallel is narrowed, the original distance between the ends of the external leads 3 is maintained.

Note that FIG. 10 shows a state in which the external leads are spread out in a fan shape.

When the external leads 3 of the semiconductor device are bent in a semiconductor device in which the resin sealing portion 2 is warped as described above, each external lead 3 is not bent uniformly, resulting in variations in height. Also, errors may occur in the lead pitch of each external lead 3.

In an example of unusual processing, when bending the external leads of a resin-sealed semiconductor device, the mold for bending the external leads is used to press the resin-sealed part so that the resin-sealed part does not warp. The external lead will have to be bent.

For this reason, even if the external leads were aligned when they were bent in the mold, when they are removed from the mold, the resin sealing part of the semiconductor device will return to a warped state, and the tips of the external leads will not be flat. The trajectory drawn by the tip of the external lead becomes an arc.

Therefore, when a semiconductor device is mounted on a printed circuit board, a situation occurs in which the external leads located at the ends in the parallel direction of the external leads arranged in parallel are not grounded to the printed circuit board. This is particularly noticeable in semiconductor devices having a large number of external leads.

A more specific explanation will be given with reference to FIG. 11.

Due to the warpage of the semiconductor device 1, the external leads 3 disposed in parallel...
The external leads 3a placed at the end portions 41'i of . Further, h occurs as a positional deviation in the height direction. Such a deviation Q, h
When a semiconductor device 1 with a certain amount of heat is mounted on a printed circuit board, all the external leads 3 cannot be mounted uniformly, which may cause contact failure.

Furthermore, as the number of external leads of a semiconductor device increases, the deviation a,)1 increases, resulting in a problem of lack of reliability.

For this reason, it is required to reduce the allowable deformation of the lead pitch dimension of the external leads in order to make the external leads finer.

On the other hand, since the length, width, etc. of the external lead differ from position to position, and the length of the internal lead following the external lead also differs, the internal stress of each lead differs. Therefore, when deforming each external lead, different internal stress acts on each external lead, and even if it is attempted to deform the same, variations will occur.

Therefore, the present invention provides a resin-sealed semiconductor device and an external part of the resin-sealed semiconductor device that can keep the tips of external leads neatly aligned even if the resin-sealed portion of the semiconductor device shrinks or warps. An object of the present invention is to provide a lead bending method and forming device.

(Means for Solving the Problems) The present invention includes the following configuration to achieve the above-mentioned object 1.

That is, as a method for processing external leads of a semiconductor device in a resin seal.

Separate the semiconductor device whose resin-sealed portion is resin-sealed from the lead frame with the tips of the extending external leads connected to adjacent external leads in groups, and connect the external leads of the semiconductor device with the connecting pieces. It is characterized in that the connected pieces are bent and then the connecting pieces are separated so that each external lead has a predetermined length.

In addition, as a forming device for external leads of semiconductor devices, there is a cutting device that separates the external leads from the lead frame with the tips of the external leads connected in groups with connecting pieces, and a folding device that bends the external leads of the semiconductor device. The present invention is characterized in that it is equipped with a bending device and an IJJ removal device for cutting off a connecting piece connecting the tip portion of the bent external lead.

(effect) Next, the operation of the present invention will be described.

A semiconductor device sealed with resin and supported on the rails of a lead frame is cut with the ends of the external leads connected by a connecting bar, and then the external leads are bent to form the external leads into a predetermined shape. , further cut out the connecting piece.

(Embodiments) Preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

FIG. 1 is a plan view showing a lead frame sealed with resin.

In FIG. 1, a semiconductor chip is bonded to the stage portion of a lead frame (2), wire bonded, and then resin-sealed to form a resin-sealed portion L4.

External leads 16 extend from two longitudinally opposing sides of the lead frame 12 on the resin-sealed portion 4 of this semiconductor device.

Further, the tip of each external lead 16 is connected to the lead frame 12.
It is integrally connected to the section par 12b.

Note that the rail 12a of the lead frame 1112 has the following.

Positioning holes and feed holes for feeding the lead frame 12 are provided.

Subsequently, the semiconductor device 1I7j10 is separated from the lead frame 12, and the semiconductor device i+! ? The procedure for bending the ten external leads 16 will be described.

■ Resin seal 11 connected to lead frame 12:
Remove the resin (resin particles) around the resin sealing part 14 of the conductor device 10 and between the external leads 16 (first
(The state of the lead frame 12 at position A in the figure).

Subsequently, as shown at position 8 in FIG.
The tips of the external leads 16 are cut off while connected by the connecting pieces 20 (referred to as a cutting process). Then, the semiconductor device 10 is separated from the lead frame 12.

Note that the connecting piece 20 connecting the tips of each external lead 16 is left as a member for connecting a part of the section par 12b. External leads 16 of this semiconductor device 10
The external leads 16 whose tips are integrally connected are referred to as an external lead group 16g.

The first step is 11J and 17J cutting and 11J.

(2) Each external lead group leg extending on two sides of the semiconductor device 57 (to) is bent into a two-character shape (referred to as a bending step, see FIG. 2). This bending step is referred to as a second step.

Note that the external lead group 16g is bent into a two-character shape by a conventionally known method.

■ External lead group 1 of bent semiconductor device 10
Cut off the connecting piece 20 at the tip of 6g.

This process is called the excision process. It is also called the third step.

The semiconductor device 10 with this connection No. 1"20 removed.

Shown in FIGS. 3(a) and 3(b).

Furthermore, the processing procedure (① to ①) of external leads using the molding apparatus for the semiconductor device 10 will be explained together with the apparatus.

FIG. 4 is a schematic diagram of one side of the forming apparatus for semiconductor devices.

The forming device 22 is a Jk stand 22Al with a flat cross-shaped shape.
Second, three first to third press machines 24A, 24B, 24C
is located.

Near the first press machine 34A, there is a supply mechanism 2 for supplying a lead frame unit in which a lead frame 12 for holding a resin-sealed semiconductor device 10 is cut into a predetermined length.
5 is provided.

The lead frame units supplied to the first press machine 24A are stored in a stacked state in the magazine 26a.

26A is a magazine supply device, and a plurality of magazines 26
a is stored. A lead frame unit is sent to a feeding position Z from each magazine 26a in this magazine supply device 26A.

Then, the lead frame unit in the magazine 26a-
When the magazine 26a becomes empty, the next magazine 26a is sent in sequence.

The lead frame unit at the feed position Z is supplied to the first press machine 24A by the supply mechanism 25.

The first step is performed in the second press a24B, and the semiconductor devices 10 separated in the first process are sent to the second press a24B by the conveyance means with the feeding direction changed to the Y direction. Note that the rail 12a is ejected as is in the moving direction.

The second press machine 24B performs a second step of bending the external lead 16 into a two-character shape.

Subsequently, the semiconductor device 10 is sent to the third press fi24c,
Perform Step 3] Step 2 of cutting off the connecting piece 20.

Reference numeral 27 denotes a feed arm for the lead frame unit, and the feed arms 27 are respectively connected to cylinders 28 to feed the lead frame unit in synchronization. Also, the lead frame 1 is connected to the second and third press machines 24B and 24C.
The semiconductor device 10 cut from the semiconductor device 2 is transported by a conventionally known transport means.

On the other hand, the semiconductor device 10 in which the connecting piece 20 at the tip of the external lead 6 is cut off by the third press machine 24C to form the external lead 16 to a predetermined length is processed by a conventionally known ejection mechanism.
It is configured to be housed in the discharge part 1-29.

Thereafter, the semiconductor device 10 is sequentially processed in the same manner.

Next, other embodiments will be described.

FIGS. 5(a) and 5(b) show the rail 1 of the lead frame 12.
With the semiconductor device 10 suspended from the external lead 16
This shows the case of bending.

FIG. 5(a) shows a plan view, and FIG. 5(b) shows a front view.

Next, regarding the case where the external leads 16 of the semiconductor device 10 are processed while being supported on the lead frame 1112, A
-C position will be explained in order.

+11 A semiconductor chip is bonded to the stage portion of the lead frame 12, wire-bonded, and then sealed with resin to form a resin-sealed portion 14.

The resin sealing part 14 of the semiconductor device 10 is supported by the rail 12a by a hanging pin 17, and the tip of each external lead (6) is integrally connected to the section part 12b of the lead frame 12 (FIG. 5A). position).

In this A (i'711), the resin (JIM resin) around the resin sealing part 14 of the resin-sealed semiconductor device (0) and between the external leads 16 is removed.

(2) Then, the tips of the external leads 16 of the semiconductor device 10 are cut off for each external lead group t6g connected by the connecting pieces 20 (this is called a cutting process, as shown in FIG. 5B (position Q)).

The first step is to remove the resin particles mentioned above and cut the cutting process.
It's called a process.

(3) External leads 16 extending to two sides of the semiconductor device 10
Fold the group into a two-character shape (referred to as a bending step: also referred to as the second step, position C).

(4) Divide the connecting piece 20 of the external lead group 16g by 9J (position D).

(5) Cut the hanging bottle 17 and attach the lead frame 12
0 from the semiconductor device (position C).

Processing of the external lead 16 at the above-mentioned position and the C position is the third step.

A forming device for performing the above-mentioned bending processes of external leads in (1) to (5) will be described with reference to FIGS. 6 and 7. FIG. 6 is a schematic front view showing a forming apparatus for semiconductor devices, and FIG. 7 is a schematic plan view of the forming apparatus.

The forming device 30 includes three first to third presses 34A, 31B, and 34G arranged in a straight line on a J, I, and table 32. A supply mechanism 36 for supplying the lead frame unit 11 cut into a predetermined length is provided near the first press machine 34A.
A semiconductor device discharge fi structure 38 is provided in several stages in C.

The lead fly 11 unit 11 supplied to the second press 34B is a semiconductor chip molded with resin and cut into a predetermined length.

The lead frame units 11 are stored in a stacked state in the magazine 36a.

36A is a magazine supply device, which feeds a plurality of magazines 36.
a is stored. In this magazine imitation device 36A, the magazines 36a are housed in parallel on the supply line M with respect to the feed position mL of the lead frame 12, and are pushed in the supply direction by the supply means. Then, when the magazine 36a is sent to the supply position i7m, the magazine 36a
The lead frame 1 is lifted by the lift device 36c located below.
Unit 11 is being pushed upwards. Lead frame unit 1 located at the top (chuck device 40
is sent to the feed position.

Then, when the uppermost lead frame unit 11 is sent, the lead frame unit 11 is pushed up by the thickness of one sheet by the lift device 36c.

Then, the lead frame unit 1 in the magazine 36a
When the magazine 36a is exhausted, the magazine 36a is sent to the right in FIG. 7 by a discharging means (not shown), and the empty magazine 3Ga is sent in the opposite direction by a feeding means (not shown).

The lead frame unit 11 at the feed position FjI is
It is sent by the cylinder 42 in the longitudinal direction of the lead frame unit 11 (the direction in which the presses are arranged) and is supplied to the first press machine 34A.

The first press fi34A to the third press fi34C are provided with a conveyance mechanism for moving and supplying the lead frame units 1 to each press.

As this conveyance mechanism, feed arms 44 are provided on the supply side and the discharge side of the mold of each press machine, respectively. Note that the second press 34B is provided only on the supply side (see FIG. 7).

The feed arms 44 are respectively connected to cylinders 45 and feed the lead frame unit 11 in synchronization.

In addition, the second and third press machines 34I3.34C have
A plurality of feed rollers are provided facing each other on both sides of the mold. This feed roller conveys the lead frame unit 11 by gripping the rail 12a and rotating it.

The first press machine 34A (cutting device) performs processing in the first step, and the second press machine 34B (bending device) and third press machine 34C (cutting device) perform processing in the second and third steps, respectively. This is what we do.

Connecting piece 2 at the tip of external lead 16 with third press machine 34C
The semiconductor device 10 which has been cut at both ends 0 and 17 is discharged by the discharge mechanism 38 .

Next, the discharge 841F will be explained.

The semiconductor devices 10 separated by the third press machine 34G are separated by a suction cup 48 provided on the robot hand 46.
- adsorb and raise it (Fig. 6, arrow a) - then move it horizontally to a predetermined position (Fig. 7, arrow b)), and lower it at this horizontal movement position (Fig. 6, arrow C), The suction by the suction ff 148 is released and the semiconductor device 10 is placed on the tray 50.

The trays 50 are stacked on a lift device (not shown) in the space below the third press machine 34G, and the uppermost tray 50
0 is configured to be sequentially pushed out into the storage frame 54 by one row by the push-out means 52.

Therefore, the pushing out of the tray 50 is synchronized with the movement of the robot hand 46, and the semiconductor device 10 is placed on the tray 50. Then, while the next semiconductor device 10 is being sent, the tray 50 is pushed out by one row.

When the tray 50 is full, the tray 50 is lowered by one step, and the primary tray 50 is similarly sent over the previous tray 50, and the semiconductor device 10 is housed therein. Further, the trays 50 can be arranged in two rows in the storage frame 54, and when the trays 50 are stored in one part, the storage frame 54 slides along the rails 56 and is stored in the other side.

In the above foaming bag type 30, the first to third press machines 34
A, 3413.34C, move the semiconductor device i! Although the case where the ten external leads 16 are bent has been described, the semiconductor devices 10 are separated from the lead frame 12 in the first press mounting 34A in a connected state for each external lead group 16g, and each semiconductor device 10 is bent. It is conveyed by a conveying device like line Q, and then the second and third press machines 3
In each of the above embodiments, the external leads 16 are extended from opposite sides of the resin sealing part 14 of the semiconductor device 10. The same applies to the semiconductor device ri from which the external leads 16 extend. Here, the procedure for bending the external lead L6 will be explained with reference to FIGS. 8(,) and (b).

+a+ Remove the resin (+, M resin) from the area surrounded by the resin sealing part 14 and dam bar 19 of the resin-sealed semiconductor device 10 connected to the lead frame 1112, and at the same time remove the outside of the semiconductor device 1Iv110. The tips of the leads 16 are separated while being connected by the connecting piece 20 (referred to as a first step).

(bl) The external lead group 16 extending to the four sides of the semiconductor device ii'tLo is bent into a two-letter shape (referred to as the second step of bending).

fc) Cut off the connecting piece 20 at the tip of the external lead group 16g of the bent semiconductor device 10 (cutting step,
(Also called the third process).

These first to third steps can be sequentially processed using the first to third press machines as described above.

In each of the above embodiments, the external leads extending from each side of the resin sealing part are connected by the connecting piece 20, but it is not necessary to connect each side by the connecting piece 20. For example, as shown in FIG. Even if a plurality of adjacent external leads 16... are connected as an external lead group 16g by the connecting piece 20, the same operation and effect can be obtained f:? It will be done.

In the above embodiment, the external leads 16 of the semiconductor device 10 are bent for each lead group 16g, so that the position of each external lead 16 is maintained and the excessive force inside the lead is prevented from escaping. averaged while
The tip position of the external lead 16 can be bent flat. Further, even if an extra force is applied to a part of the external lead 16, the force is expended by elastic deformation and plastic deformation in equilibrium with the surroundings, and the balance is maintained.

It goes without saying that the present invention is not limited to the embodiments described above, and that many modifications can be made without departing from the spirit of the invention.

(Effects of Issuing t!I'J) The present invention is constructed as described above, and produces remarkable effects as shown below.

l) Since the external leads of the semiconductor device are bent with the ends of the external leads connected by a connecting piece, the position of each external lead is maintained, and the excessive force inside the lead is released and the average 1'1. It can be set as

2) In addition, since the tip of the external lead is carried and delivered, even if excess force is applied to a part of the connected external lead, the force is dissipated by elastic deformation and plastic deformation in equilibrium with the surrounding area, and the balance is maintained. It will be planned. Also.

When the force cannot be absorbed, it is released to other connected parts. In the process of applying such force, the internal stress contained in each external lead is neutralized, reduced, and averaged, so that each external lead can maintain its predetermined position even after being cut.

3) Furthermore, the degree of warpage of the semiconductor device also differs due to the difference in the shrinkage rate due to the difference in the type of press of the +y4 resin sealing resin, but this point was not taken into account.

According to the present invention, the position of the tip of the external lead can be kept constant.

[Brief explanation of the drawings] Fig. 1 is a partial plan view showing a state in which a resin pair +1 = shunted semiconductor device is supported on a lead frame, and Fig. 2 is a partial plan view showing a state where the semiconductor device is separated from the lead frame and the external leads are bent. 3 is a plan view and a front view showing a state in which connecting pieces of an external lead group of a semiconductor device are removed; FIG. 4 is a plan view of a forming device for a semiconductor device; FIG. 6 is a plan view and a front view showing a bending procedure for bending an external lead of a semiconductor device while it is supported by a lead frame, FIG. 6 is a front view of a forming device for a semiconductor device, and FIG. FIG. 8 is a partial plan view showing a state in which a resin-sealed semiconductor device is supported on a lead frame; FIG. 9 is a plan view showing a state in which the semiconductor device is separated from the lead frame;
The figure shows the external leads of a semiconductor device.
A plan view showing a state where each 6 g is connected with a connecting piece, 1st
Figure 0 is an explanatory diagram showing a state in which the resin sealing part is contracted.
The figure is a front view showing the semiconductor device in a warped state. 10 ・ (1 ・ (2 ・ 14 ・ 16 ・ 16 to 20 ・ 30 ・ Semiconductor device. Lead frame unit lead frame. Resin sealing part, external lead, ・External lead group, connection) 7. Forming device.

Claims (1)

[Claims] 1. Separate a semiconductor device whose resin-sealed portion is resin-sealed from a lead frame with the tip portions of the extending external leads connected to adjacent external leads in groups; External leads of a resin-sealed semiconductor device, characterized in that the external leads of the device are bent while connected by connecting pieces, and then the connecting pieces are separated so that each external lead has a predetermined length. How to bend. 2. A resin-sealed semiconductor device characterized in that the tip portions of adjacent external leads are connected to each other in groups by connecting pieces. 3. A processing device for bending external leads of a resin-molded semiconductor device, a cutting device for cutting off the external leads from a lead frame with the tips of the external leads connected by connecting pieces in each adjacent group; A forming device comprising: a bending device that bends an external lead of a semiconductor device into a predetermined shape; and a cutting device that cuts off a connecting piece connecting the tip of the bent external lead.