JPS6226180B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a positioning device for semiconductor pellets (hereinafter referred to as pellets).

Generally, to make semiconductor devices (such as LSI), pellets are first fixed to the pellet attachment part of a lead frame using ultrasonic waves, etc., but before the pellets are transferred to the pellet attachment part, a number of pellets are first fixed. The pellets are transferred one by one from the pellet storage container in which the pellets are stored in an orderly manner to a pellet positioning device, where the pellets are positioned, and then the pellets that have been positioned are placed in a pellet suction unit at the lower end. The pellets are sucked up by a collector and transferred to the pellet attachment section of the lead frame.

This is because the collet makes a constant reciprocating motion and only ejects the pellets adsorbed at the lower end to the pellet attachment part, so that when the pellets are released, they are placed correctly in the pellet attachment part of the lead frame. This is because the position of the pellet to be adsorbed to the collet is determined in advance by a positioning device.

However, these pellets come in a variety of sizes, and pellets of a fixed size are not always transferred to the lead frame. For example, in the case of a hybrid type, pellets of different sizes or even square shapes are transferred. In addition, rectangular pellets must be sequentially transferred to the pellet mounting section.

Therefore, the present invention provides a method for positioning semiconductor pellets that can not only be used to sequentially transfer pellets of a certain size to a pellet mounting section, but also meet the requirements for sequentially transferring pellets of different sizes and shapes as described above. The purpose is to provide equipment.

Hereinafter, one embodiment of the present invention will be described with reference to the drawings.

FIG. 1 is a plan view of a pellet positioning device showing an embodiment of the present invention, and FIG.
A cross-sectional view is shown. In the figure, reference numeral 1 denotes a base plate, and a pellet mounting table 2 is provided on the base plate 1. Reference numerals 3 and 3' denote guide grooves having a shape as shown in FIG. Since they have the same configuration, only one direction will be explained below. This guide groove 3,
3' is slidably provided with pellet positioning bodies 5, 5' each having pellet holding jaws 4, 4' on its upper surface. Also, 8 is a left and right opposite screw 6, 7
The shaft has guide grooves 3, 3' on the back side of the base plate 1.
This shaft 8 is rotated by a pulse motor 9 that can rotate in both forward and reverse directions. The left and right opposite screws 6 and 7 provided on the shaft 8 each have a female screw piece 10, which constitutes a moving body.
11 are screwed together, and this female screw piece 1
0 and 11 have shafts 12 and 13 protruding from them, respectively. 14 and 15 are guide grooves 3 and 3' in the base plate 1.
A shaft 12 protruding from the female threaded piece 10 passes through this elongated hole 14 and is fixed to the pellet positioning body 5, and the female threaded piece 11
A shaft 13 (a portion for moving the pellet positioning body 5') protruding from the pellet positioning body 5' passes through the long hole 15 and fits into a long groove 16 bored in the direction of the guide groove 3' on the back surface of the pellet positioning body 5'. has been done. Positioning body 5'
is always pressed toward the pellet mounting table 2 by a coil spring 18 stretched between the positioning body 5' and a fixing piece 17 provided at the end of the guide groove 3'. n is the clearance provided between the pellet positioning body 5' and the shaft 13. m indicates the pellet clamping interval of the pellet clamping jaws 4, 4', and 19 is a pulse motor control device that numerically sets a value corresponding to the clamping interval m, for example, the clamping interval m itself. This interval m
is stored as the rotation speed of the pulse motor 9 based on the set value, and the pulse motor 9 can be driven and stopped based on the stored rotation speed.

Further, in FIG. 2, a is a pellet clamping interval setting window which shows the numerical value of the pellet clamping interval m entered using the numerical value setting button b, and c
indicates the start button.

The pulse motor control device 19 causes the pellet clamping interval setting window a to display the numerical value of the pellet clamping interval m using the numerical setting button b, stores the numerical value, and presses the start button c to change the value to the stored numerical value. Since it is extremely easy to rotate the pulse motor 9 by a corresponding amount and then stop it using the current electronic technology level, a description of the internal structure will be omitted.

Next, the operation of the above configuration will be explained.

First, in the pulse motor control device 19, the interval m that the pellet clamping jaws 4, 4' should take on the pellet mounting table 2 is set in the pellet clamping interval setting window a by pressing the numerical setting button b. Next, place the pellets one by one from the pellet storage container onto the pellet mounting table 2,
When start button c is pressed, pulse motor 9 starts and shaft 8
is rotated in one direction, and the pair of female screw pieces 10, 11
are approaching each other with respect to the center O of the pellet mounting table 2. When the distance between the pair of pellet clamping jaws 4, 4' reaches the pellet clamping distance m, the rotation of the pulse motor 9 is stopped by a command from the pulse motor control device 19, and the rotation of the shaft 8 is also stopped. As a result, the pellets placed on the pellet mounting table 2 are held and accurately positioned by the pellet holding jaws 4, 4' of the pellet positioning bodies 5, 5' from two orthogonal directions. After positioning, the pellet positioning bodies 5, 5' are separated from each other in opposite directions by the reverse rotation of the pulse motor 9, and return to the initial position. The pellets are adsorbed and transferred to the pellet attachment part of the lead frame.

As shown in FIG. 2, the pellet positioning body 5'
and the shaft 13 of the female screw piece 11 are fitted in the long groove 16, and the pellet positioning body 5' is attached to the pellet mounting table 2.
The reason why the coil spring 18 is used to press the pellet in the direction of When the pellet positioning bodies 5, 5' are subjected to force due to variations, etc., in order to eliminate the force and prevent excessive force from being applied to the pellets, one of the positioning bodies 5 and the pellet holding jaw 4 are , the screw 6 of the shaft 8, the female thread piece 10, etc. are precisely machined so that the pellet positioning body 5 side becomes the reference when positioning the pellet on the pellet mounting table 2, then the other positioning body 5' This is to ensure that the drive structure using the side screws 7 can operate accurately even if the accuracy is somewhat reduced or there are machining errors.

The above embodiment has the following effects. That is, since the shaft 8 for moving the pellet positioning bodies 5, 5' is driven by the pulse motor 9, the setting of the pellet clamping interval m can be easily changed. Since a pulse motor 9 is provided separately for each of the pellets, it is possible to move each pair of pellet positioning bodies 5, 5' independently.
If they are set the same in two orthogonal directions on the pellet mounting table 2, square pellets can be positioned, and if they are set at different intervals, rectangular pellets can also be positioned. Also, at that time, a pair of pellet positioning bodies 5,
5' is rotated in the X direction or in the Y direction by the rotation of the shaft 8.
Since the pellets are moved by the same amount in the direction, the center (intersection of two diagonal lines) of the positioned pellets can be kept almost constant on the pellet mounting table 2 regardless of its size and shape. The pellet positioning bodies 5 and 5' are stopped when the distance between the respective pellet clamping jaws 4 and 4' reaches the pellet clamping distance m, so that positioning can be performed without applying almost any clamping force to the pellet during clamping. .

In addition, the pellet clamping interval m can be easily changed by simply setting the pellet clamping interval setting window a using the numerical setting button b of the pulse motor control device 19. Even pellets of different sizes can be changed using the same positioning device. positioning can be performed.

Further, by providing the clearance n, even if there is an error in the pellet size, no excessive force is applied to the pellet or the positioning device, and the pellet can be accurately positioned.

Furthermore, by driving the shaft 8 with a pulse motor 9, the shaft 8 can be set to rotate quickly at first and slow down when the distance between the pellet clamping jaws 4 and 4' approaches m. Clamping jaw 4,
4' can be moved in a short period of time until it comes into contact with the pellet.

In the above embodiment, the pulse motor 9 is used as the drive source.
Although the present invention has been explained using an example using a motor, the invention is not limited to this, and can also be applied to, for example, a stepping motor, a stepping motor, a digital motor, etc.

As explained above, according to the present invention, accurate positioning can be performed regardless of the size and shape of the semiconductor pellet, and the center position of the positioned semiconductor pellet can be kept almost constant on the pellet mounting table. During positioning, excessive clamping force is not applied to the semiconductor pellet.

[Brief explanation of the drawing]

FIG. 1 is a plan view of a pellet positioning device showing an embodiment of the present invention, and FIG.
The cross-sectional view, FIG. 3, is a cross-sectional view in FIG. DESCRIPTION OF SYMBOLS 1...Base plate, 2...Pellet mounting table, 4, 4'...Pellet clamping jaws, 5,5'...Pellet positioning body, 8...Shaft, 9...Pulse motor, 10, 11...Femally threaded piece, 12, 13 ...Shaft, 14, 15...Long hole, 1
8... Coil spring, 19... Pulse motor control device, a... Pellet clamping interval setting window, b... Numeric value setting button, c... Start button, m... Pellet clamping interval, n
...play gap, O...center.

Claims (1)

[Claims] 1. With respect to the pellet loading table, move the pellet positioning bodies supported by a pair of movable bodies facing each other toward and away from each other in two directions orthogonal to each other.
In the semiconductor pellet positioning device, the semiconductor pellets placed on the pellet mounting table are clamped and positioned by bringing the pairs of pellet positioning bodies closer to each other by moving the movable body. Among the pellet positioning bodies, one of the pellet positioning bodies is fixedly supported on the corresponding movable body, and the other pellet positioning body is elastically supported on the corresponding movable body. A drive unit for synchronously approaching and separating each pair of moving bodies by the same amount, and a driving unit for moving each pair of pellet positioning bodies so as to correspond to the semiconductor pellet placed on the pellet mounting table at the time of the approach. 1. A semiconductor pellet positioning device comprising: a control section that controls the drive section so as to stop the movement of the semiconductor pellet when a preset clamping interval is reached.