JPH0223025B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a brazing material supplying device in the die bonding process of semiconductor IC chips, particularly when bonding with a eutectic alloy that requires a brazing material.

In general, die bonding of semiconductor pellets for integrated circuits, transistors, etc. includes two methods: one using paste and the other using eutectic alloying on the bonding surface of the pellet. However, in order to obtain good thermal and electrical contact, An excellent fixing method is eutectic alloying. The fixing method using eutectic alloying involves rubbing the pellet against the pellet-fixing surface of the lead frame or case at a high temperature of 400°C or higher to form a bond between the metal such as Au on the pellet-fixing surface and the silicon on the back of the pellet. to cause a eutectic alloying reaction,
It is used to glue pellets together. When the pellet size is large, when you want to obtain a denser pellet adhesion state, or when you want a special alloy bond,
It is necessary to supply a piece of foil to serve as the brazing material on the pellet placement surface, but conventionally a tape-shaped brazing material is cut to the required length according to the size and shape of the pellets and then supplied before the pellets are placed. ing. however,
In the IC assembly process where a wide variety of products are being produced, the pellet size is frequently changed, and it is necessary to change the width of the raw material and the cutting length of the raw material each time. There was a strong need for a device that could change the amount of material supplied.

The object of the present invention is to provide a soldering material for a die bonder that makes it unnecessary to change the cutting length of the soldering material at all, and that can supply soldering material over the range necessary for die bonding of pellets, regardless of pellet size or shape. The purpose is to provide a supply device.

In order to achieve the above object, the present invention provides a brazing material supplying device for a die bonder that supplies a tape-shaped brazing material to a pellet mounting surface of a lead frame or a case, etc., on which semiconductor pellets are to be die-bonded. The apparatus main body is equipped with a cutter for cutting foil pieces of a fixed size, and a brazing material supply arm that adsorbs the brazing material foil pieces cut by the cutter and supplies them onto the pellet mounting surface. It is mounted on a stage that can move in biaxial directions on a horizontal plane, and the movement and stop position of the stage is controlled in synchronization with the feeding operation of the brazing material foil pieces by the brazing material supply arm, and the pellets to be die bonded are The present invention is equipped with a control section that selectively sets the supply position of the brazing material foil pieces by the brazing material supply arm to a predetermined vertical and horizontal position of a matrix according to the size and shape.

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

FIG. 1 shows an example of the configuration of a die bonder. In FIG. 1, a frame 3 is supplied and conveyed by a frame conveyance claw 2 from a frame supply section 1.
A brazing material foil piece 5 made of Au or the like is obtained by cutting a tape-shaped brazing material 4 into an appropriate length using a tape cutter (not shown), and is supplied by a brazing material supplying arm 6, and further sent over a heating conveyance section 7 to a die bonding position. On the other hand, the semiconductor pellet 8 to be die bonded is aligned on a pellet alignment stage 9 using a pellet attitude recognition device (not shown), and is fixed onto the frame 3 by a die bonding arm 10. 11 is a lead frame storage section. As the pellet size and shape change, the amount and position of brazing material to be supplied will be changed.
Since the foil pieces 5 reciprocate at a constant stroke between the heating conveyance section 7 and the tape-shaped brazing material 4, the foil pieces 5 are supplied to a fixed position on the frame 3. Therefore, the position and supply of the foil pieces 5 are Adjustment of the amount had to be done manually by workers. Therefore, as shown in FIG. 2, the present invention includes a brazing material supply device that includes a tape-shaped brazing material 4, a cutter 13 for cutting the brazing material 4 into a predetermined length, and a brazing material foil cut by the cutter 13. Focusing on the fact that it is equipped with a brazing material supply arm 6 that sucks the pieces 5 and moves them up and down and back and forth to supply them to the pellet mounting surface of the frame 3, the main body S of the brazing material supplying device is as follows. 2 by two pulse motors 12, 12 in synchronization with the supply operation.
It is installed on a stage 9 that is driven on a horizontal surface in the axial direction. In the present invention, the function of the cutter 13 is to set the cutting interval so that the tape-shaped brazing material is cut into a fixed size, for example, a square. Then, the feeding device according to the present invention drives and controls the stage 9 to stop it at an arbitrary position arranged in a matrix in the vertical and horizontal directions according to a command from the control unit,
The supply arm 6 supplies the foil pieces 5 in a maximum of 3×3 matrix as shown in FIG.
6' shows the state in which the supply arm 6 supplies the foil piece 5 to the frame 3.

In the present invention, in addition to supplying one piece of brazing material foil 5 cut to a fixed size as shown in FIG. Automation is easy because the supply amount and layout of the soldering material can be controlled freely on the software by selecting a combination of the following.Also, since the appropriate amount of soldering material supply and the placement pitch of the soldering material can be set, die bonding using precious metals is possible. This contributes to cost reduction in the process. The brazing material supply operation is repeated as many times as the number of pellets to be supplied, but it can be done while the pellets are swinging, and if more than one brazing material is required, the pellet size is large and the swinging time is long, so the machine It has no negative effect on the index.

As described above, according to the present invention, the supply amount and arrangement of brazing material can be set arbitrarily according to the size and shape of each pellet, so it is possible to reduce the cost of brazing material, and all of these can be controlled by software. This has the effect of making it possible to achieve full automation.

[Brief explanation of drawings]

Fig. 1 is an explanatory diagram of the configuration of a die bonder, Fig. 2 is a configuration diagram showing an embodiment of the present invention, Fig. 3 is a brazing material supply arrangement diagram of this embodiment, and Figs. 4 to 4 are examples of a brazing material supply method. FIG. 1...Lead frame supply section, 6...Raw material supply arm, 9...Stage.

Claims (1)

[Claims] 1. In a brazing material supplying device for a die bonder that supplies a tape-shaped brazing material to a pellet mounting surface of a lead frame or a case, etc. on which semiconductor pellets are to be die-bonded, a cutter and a cutter are used to cut the tape-shaped brazing material into foil pieces of a certain size. , the apparatus main body is provided with a brazing material supply arm that adsorbs the brazing material foil pieces cut by the cutter and supplies the brazing material foil pieces onto the pellet mounting surface, and the apparatus main body is movable in biaxial directions on a horizontal plane. It is mounted on a stage, and the movement and stop position of the stage are controlled in synchronization with the feeding operation of the brazing material foil pieces by the brazing material supply arm, and the above-mentioned pellets are adjusted according to the size and shape of the pellets to be die bonded. 1. A brazing material supplying device for a die bonder, comprising a control section that selectively sets the supplying position of brazing material foil pieces by a brazing material supplying arm to predetermined vertical and horizontal positions of a matrix.