JPH07161892A - Method and apparatus for lead forming - Google Patents

Abstract

PURPOSE:To cope with multiple kinds of semiconductor devices in a short time with the exchange of a minimum number of parts. CONSTITUTION:1 is a package pedestal for putting a semiconductor device 2 on, 10 is a lead pedestal, and 16 is a molding piece. The molding piece 16 is movable in the upward and downward directions and in the right and left directions in synchronized way, and the lead pedestal 10 is movable in B direction synchronized with the bending speed of a lead.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lead molding apparatus and a molding method for bending externally drawn leads of a semiconductor package for encapsulating a transistor or a semiconductor integrated circuit.

[0002]

2. Description of the Related Art An example of this type of lead forming apparatus is disclosed in Japanese Patent Application Laid-Open No. 2-284454. That is, the semiconductor device mounted on the lower molding die is pressed by the upper die pressing member, and the leads are pressed by the pressing member on the lead bending die portion integrally formed on the lower molding die to bend the lead. It is a thing. Another lead forming device is disclosed in Japanese Utility Model Laid-Open No. 20348/1990. What is disclosed here is that the leads are bent by a molding roller attached to the upper die set and a die attached to the lower die set.

[0003]

By the way, as is well known, in this type of semiconductor device, a QFP (quad flat) is used.
package), SOP (small outline package), TSOP
(Thin small outline package) and other types of different types depending on the lead shape. The above-mentioned conventional lead forming devices are all for these different types.
Since these are mold types, each of which has a lead bending mold part corresponding to its shape, there is a problem that the cost for manufacturing the mold and the time for replacing the mold are long.

Therefore, the present invention has been made in view of the above-mentioned problems of the prior art, and an object of the present invention is to replace a minimum number of parts for a wide variety of semiconductor devices.
Moreover, it is an object of the present invention to provide a lead forming apparatus and a forming method thereof that can be dealt with in a short time.

[0005]

In order to achieve this object, a lead forming apparatus according to the present invention comprises a first forming piece moving means for moving a forming piece to the left and right, and a first forming piece moving means for moving a forming piece up and down. And 2 forming piece moving means. Further, the lead forming apparatus according to the present invention comprises a moving means for moving the lead receiving base for receiving the leads to the left and right.

[0006]

According to the present invention, various bending shapes can be selected by appropriately selecting the left and right movements and the up and down movements of the molding piece in accordance with various types of semiconductor devices. Further, by synchronizing the bending of the leads and the lead receiving base, abrasion does not occur between the leads and the lead receiving base.

[0007]

An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a side view of an essential part showing a state of bending of a lead in a lead forming apparatus according to the present invention, FIG. 2 is a front view of the lead forming apparatus according to the present invention, and FIG. 3 is a block diagram of the same control section. In these figures, 1 is a package pedestal on which the semiconductor device 2 is mounted, 3 is an air cylinder for moving the pad 4 up and down, 5 is a servomotor A, 6 is a ball screw portion that rotates integrally with the rotary shaft of the servomotor A5, 7
Has one end connected to the ball screw portion 6 side and the other end connected to the sliding member 9, and is supported so as to be swingable about a central fulcrum 8. It is a lead cradle that moves to.

Reference numeral 12 is a servo motor B, 13 is a ball screw portion that rotates integrally with the rotation shaft of the servo motor B12, 14 is a servo motor C, 15 is a ball screw portion that rotates integrally with the rotation shaft of the servo motor C14, and 16 is a ball. The ball screw portion 15 moves in the left-right direction by the rotation of the screw portion 13 and
It is a molding piece that moves in the vertical direction by the rotation of. 20,
Numerals 21 and 22 are driver circuit sections connected to and driven by the servomotors A5, B12, and C14, respectively, and 23 centrally controls these driver circuit sections 20, 21, and 22 to simultaneously control the servomotors A5, B12, and C14 (circular arcs). It is a numerical control unit that is an overall control unit that performs interpolation and linear interpolation).

Next, the molding operation of the lead molding apparatus thus constructed will be described. First, the semiconductor device 2 whose leads are cut off is placed on the package cradle 1, and the air cylinder 3 is operated to lower the pad 4 to fix the semiconductor device 2 to the package cradle 1. Next, the servomotors B12 and C14 are operated to move the ball screw parts 13 and 1
1, the molding piece 16 is moved in the leftward and downward directions in FIG. 1, that is, along the arcuate locus 19 that combines these.

With the movement of the molding piece 16, the lead 1
7, the root portion is first bent along the package cradle 1, and the tip portion 18 abuts the lead cradle 10,
The tip is bent into an L shape. At this time, the servomotor A5 operates to move the lead pedestal 10 to the tip portion 18
It moves in the B direction in synchronization with the moving speed in the left direction of. Therefore, the tip portion 18 does not slide on the lead receiving portion 10, and the solder plating layer for good soldering is not scraped off on the surface of the lead 17.

Here, when the leads of semiconductor devices of different types are formed, the numerical control unit 23 changes the forming data according to the bending process of the leads.
As a result, the arcuate locus 19 of the molding piece 16 is changed, and the movement disclosure timing and movement speed of the lead receiving base 10 are changed, whereby lead molding suitable for the type is performed. Therefore, when the type is changed, the package pedestal 1 and the pad 4 may be exchanged according to the shape of the semiconductor device, and the exchange time is significantly shortened as compared with the conventional one, and the type is changed. Since it is only necessary to change the molding data of the numerical control unit 23 without preparing a mold according to the change of No. 1, it is possible to reduce the mold cost.

In this embodiment, the servo motor is used as the moving means for the lead receiving base 10 and the molding piece 16, but the invention is not limited to this, and a stepping motor may be used, and various design changes are possible. Needless to say.

[0013]

As described above, according to the present invention, the first molding piece moving means for moving the molding piece to the left and right and the second molding piece moving means for moving the molding piece up and down are provided. Since the forming piece moving means is synchronized with each other according to the shape of the lead, it is possible to cope with a change in product type.

Further, since the lead pedestal for receiving the lead is moved to the left and right so as to be synchronized with the movement of the lead after the tip of the lead comes into contact with the lead, the tip of the lead is not worn. Therefore, the solder plating layer on the lead surface is not scraped off, and good soldering can be maintained.

Further, when the type of product is changed, the minimum part replacement is required in accordance with the shape of the semiconductor device, the time for replacing parts is significantly shortened, and the product type is changed. Since it is only necessary to change the molding data of the integrated control unit without preparing a mold, it is possible to reduce the mold cost.

[Brief description of drawings]

FIG. 1 is a side view of essential parts showing a state of a forming operation in a lead forming apparatus according to the present invention.

FIG. 2 is a front view of the lead forming apparatus according to the present invention.

FIG. 3 is a block diagram of a control unit of the lead forming apparatus according to the present invention.

[Explanation of symbols]

 1 Package Cradle 2 Semiconductor Device 4 Pad 5 Servo Motor A 6, 13, 15 Ball Screw Section 10 Lead Cradle 12 Servo Motor B 14 Servo Motor C 16 Forming Piece 17 Lead 19 Circular Trajectory 20, 21, 22 Driver Circuit Section 23 Numerical control unit

Claims (5)

[Claims] 1. A lead forming apparatus for fixing a semiconductor device mounted on a package cradle with a pad and bending and forming a lead with a forming piece, wherein first forming piece moving means for moving the forming piece to the left and right. And a second molding piece moving means for moving the molding piece up and down. 2. The lead forming apparatus according to claim 1, further comprising lead pedestal moving means for moving the lead pedestal for receiving the leads to the left and right. 3. The lead forming apparatus according to claim 2, wherein the first and second forming piece moving means and the lead cradle moving means are composed of a motor and a ball screw. apparatus. 4. The lead forming apparatus according to claim 3, further comprising a driver circuit unit that drives each of the motors, and an integrated control unit that integrally controls the driver circuit units. . 5. A method of molding a lead, comprising bending a lead of a semiconductor device along an arcuate locus and moving a lead receiving base for receiving the lead in synchronization with the molding piece.