JPH11145329A - Method for forming solder ball of bga-type semiconductor device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To receive and hold solder ball chips, which are punched out in a solder plate with a press, at predetermined locations where solder balls are to be arranged and in a constant position with good accuracy, even if the solder ball chips are small in size and are large in number, without falling, rolling, or dropping the solder ball chips because of impact. SOLUTION: This method comprises a process of forming solder balls as external connection electrodes on the substrate of a semiconductor device. In this process, solder ball pieces 11 are punched out with a press 2 in a solder plate 8 from the bottom side thereof in the arrangement of the solder balls and are stuck to a movable transfer tape 2, which is provided above the solder plate 8 and with an adhesive and is moved after the press 22 punches the solder pate 8, and then the solder ball chips 1 stuck to the transfer tape 12 are transferred to the substrate.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for forming a solder ball of a BGA type semiconductor device.

[0002]

2. Description of the Related Art A BGA type semiconductor device has been proposed to reduce the size, speed, or increase the number of pins of a semiconductor device.
In the BGA type semiconductor device, for example, a semiconductor chip is fixedly mounted on a substrate provided with a wiring pattern with an adhesive, terminals of the semiconductor chip are connected to the wiring pattern by wires, and the semiconductor chip and the wiring pattern are connected. A solder ball is provided on the substrate as an external connection electrode, and the wiring pattern and the solder ball are electrically connected via a through-hole.

As shown in FIG. 4A, a conventional solder ball is formed on a substrate by forming a spherical solder ball 2 housed in a solder ball storage container 1 into a suction hole 3 in a lattice shape. A predetermined number of pieces are taken out by a suction head 4 provided in the above, transferred to a land 6 formed on a substrate 5 as shown in FIG. . Note that, in FIG.
Is an intake path.

[0004] In this method, if the number of solder balls per board is set to, for example, about 500, there is no problem. However, when the number of solder balls is increased, it is difficult to adsorb a predetermined number, for example, all 1000 pieces, to the suction head without leakage, and the accuracy of setting the solder balls on the substrate is deteriorated. When the size of the solder ball is reduced, for example, the diameter becomes 0.76 mm to 0.2 mm.
When it is less than mm, the installation accuracy is further deteriorated, and a re-placement operation has to be performed to lower the productivity.

As a method of forming a solder ball on another substrate,
It has been proposed that a solder ball piece is punched from a solder metal plate by a press, and the punched solder ball piece is transferred to a land of a substrate and installed.

[0006]

However, the solder ball pieces punched by the punches and dies of the conventional press may fall down on the receiving plate, fall down, or fall due to impact. Since the solder ball pieces are not spherical, they are difficult to handle and require time and effort to install the solder ball pieces on the land of the board.

According to the present invention, a solder ball piece stamped from a solder metal plate by a press is received and held at a predetermined position and in a fixed posture without falling down, falling down, or falling due to impact, etc. An object of the present invention is to form a solder ball by accurately setting even a small number of solder ball pieces and a large number of solder ball pieces at a ball arrangement position.

[0008]

SUMMARY OF THE INVENTION The gist of the present invention is to provide a method of forming a solder ball as an external connection electrode on a substrate of a BGA type semiconductor device on which a semiconductor chip is mounted. The pieces are sequentially punched out from the lower side to the upper side in a solder ball arrangement of the board by a press, and a transfer tape with an adhesive provided movably upward is mounted on the board in accordance with the punching of the press. The punched solder ball pieces are applied to the board by traveling the length corresponding to the arrangement interval, and the solder ball pieces attached to the transfer tape with the adhesive are transferred to the substrate.

[0009]

Next, an embodiment of the present invention will be described with reference to the drawings. In the drawings, reference numeral 8 denotes a solder metal plate, for example, a lead or lead alloy metal plate or the like is employed. The solder metal plate 8 is punched upward from below by a punch 9 and a die plate 10 provided below, and the punched solder ball piece 11 travels upward while being mounted on the punch 9. The adhesive tape is attached to the transfer tape 12.

First, the configuration of the press die apparatus 22 will be described. A movable bed 13 is provided with the punch 9 via a punch plate 14 and is moved up and down. A fixed stripper 15 is provided between the die plate 10 and the punch plate 14. The fixed stripper 15 is such that the punch 9 has a movable bed 1.
When it rises by the operation of 3, it rises together and clamps the solder metal plate 8 with the die plate 10. The metal piece for soldering 8 is punched out by the punch 9 in the state of being pressed. In addition, 16 is a post.

In this embodiment, the solder metal plate 8 runs from the front side to the back side of the paper. 1
7 is a traveling guide.

Reference numeral 18 denotes a fixed type ram, on which a transfer tape 12 with an adhesive is provided under a tape support base 19 so as to run freely. The transfer tape 12 with the adhesive is applied to the solder board of the substrate 5 at every stroke of the punch 9 moving up and down.
The operation is performed by a separate operation program so that the vehicle travels by the length of the array interval. In this embodiment, the transfer tape 12 with the adhesive is moved from the front side to the back side of the paper surface in the same manner as the solder metal plate 8 in this embodiment.

Reference numeral 20 denotes the transfer tape 1 with the adhesive.
A traveling guide 21 is a jig for attaching the die plate 10 to the fixed ram 18.

In FIG. 1, eight punches 9 are provided in series, but this is for the sake of simplicity of the drawing, and the number corresponds to the number of solder balls 2 arranged in one row on the substrate 5. It is desirable to install the punch 9 of the above. In addition, depending on the number and the size of the arrangement in one row, they may be installed separately in front and rear.
Further, the punch 9 may be installed on the punch plate 14 via a tape plate, for example, so that the intermittent operation can be freely performed, and only the necessary punch 9 may be operated.

The press die apparatus 22 according to the present invention is constructed as described above. Next, a method of installing the solder ball pieces 11 on the substrate 5, which partially overlaps with the above, will be described.

The movable bed 13 is operated to punch the solder metal plate 8 from below by the punch 9 and the die plate 10, and the punched solder ball piece 11 is supported so as to be able to run upward. Is adhered to the transfer tape 12 provided with an adhesive. At this time, since the punched solder ball pieces 11 are mounted on the transfer tape 12 with the adhesive while being supported by the punch 9, the same attitude is maintained at a predetermined position without falling down or falling down. Can be worn with

After the application, the transfer tape 12 with the adhesive is known in advance while the punch 9 is lowered to the bottom dead center below the metal plate 8 for soldering. Run for the length of the array distance.

Subsequently, the punch 9 is operated upward again to punch the solder metal plate 8 in the same manner as described above, and the punched solder ball piece 11 is attached to the transfer tape 12 with the adhesive.
By repeating this operation, the transfer tape with adhesive 1
2, solder ball pieces 11 are attached in the same arrangement as the solder ball arrangement state of the substrate 5.

Thereafter, the solder ball piece 11 attached to the transfer tape 12 with the adhesive is transferred to the land 6 of the substrate 5 and installed. Next, the solder ball 2 is formed on the substrate 5 by heating and melting.

Further, in the present invention, the solder ball pieces are placed on a substrate on which the semiconductor chip is mounted. The substrate may be a substrate on which the semiconductor chip is mounted directly or indirectly via another member. It also includes mounting.

[0021]

According to the present invention, a solder ball is formed by pressing.
The solder ball piece is punched upward from the lower side and adhered to the transfer tape with adhesive as it is, so that the solder ball piece does not fall down or fall down due to its own weight or impact, etc. Wear in a certain posture. In addition, the solder ball pieces can be installed on a substrate without being chipped even if the number of solder ball pieces is large or small.

[Brief description of the drawings]

FIG. 1 is a diagram showing punching of solder ball pieces according to one embodiment of the present invention.

FIG. 2 shows a transfer tape with an adhesive in one embodiment of the present invention.
Solder ball formed by transferring a solder ball piece from a board to a substrate
FIG.

FIG. 3 is a side view showing a state where a solder ball is formed on a substrate in one embodiment of the present invention.

FIG. 4 is a view for explaining a conventional solder ball installation on a substrate.

[Explanation of symbols]

 2 Solder Ball 5 Substrate 6 Land 8 Solder Metal Plate 9 Punch 10 Diplate 11 Solder Ball Piece 12 Transfer Tape with Adhesive 13 Movable Bed 14 Punch Plate 15 Fixed Stripper 16 Post 17 , 20 traveling guide 18 fixed ram 19 tape support 21 mounting jig 22 press die device

Claims (1)

[Claims] 1. A method of forming a solder ball as an external connection electrode on a substrate of a BGA type semiconductor device on which a semiconductor chip is mounted, wherein a solder ball piece is pressed from a lower side of a metal plate for solder by pressing. The punching was performed sequentially in a solder ball array, and the transfer tape with adhesive provided so as to be able to run upward was run for a length corresponding to the solder ball array interval of the substrate in accordance with the punching of the press. A method of forming a solder ball for a BGA type semiconductor device, comprising: attaching a punched solder ball piece; and transferring the solder ball piece attached to the tape to the substrate.