JPH0831495B2 - Bonding device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention is applied to a bonding technique, and more particularly to a technique for bonding a semiconductor pellet to an inner lead held on a carrier tape in an assembly process in manufacturing a semiconductor device. It relates to effective technology.

[Conventional technology]

For the inner lead bonder used in the assembly process in the manufacturing of semiconductor devices, see Industrial Research Institute, Showa
Issued on November 10, 1960, "Electronic Materials, November 1985 Separate Volume"
(P145-P149)

The outline is that the semiconductor pellet is placed at a predetermined position on the bonding stage, the inner leads formed on the surface of the carrier tape are continuously conveyed to this bonding stage, and the bonding tool is lowered from directly above it by pressing and heating. The semiconductor pellet is bonded to the inner lead via a bump formed in a part of the semiconductor pellet.

In the above bonding apparatus, it is important that the contact surface of the bonding tool (hereinafter simply referred to as “tool”) is in parallel contact with the semiconductor pellet (hereinafter simply referred to as “pellet”) mounted on the bonding stage. Maintaining the parallelism prevents bumps from coming into contact with the tool, so that it is necessary to adjust the parallelism between the contact surface of the tool and the pellet before bonding.

This adjustment of parallelism has been conventionally performed on the tool side. For example, when the base end of the tool is fixed to an elevating arm for elevating the tool, the tool contact surface and the bonding stage become parallel. Is adjusted.

[Problems to be solved by the invention]

However, when a semiconductor device is manufactured using the above-mentioned bonding apparatus, even if the parallelism between the contact surface of the tool and the pellet is adjusted, the bonding failure between the bump and the inner lead and the tool Bonding failure such as pellet damage may occur due to excessive pressing force.
The present inventor has found that one of the causes of these defective bonding is the parallelism adjusting step.

That is, since there is a problem that it is difficult to obtain high accuracy in the adjustment of parallelism performed on the tool side as described above, this causes problems such as uneven contact of bumps on the tool, which in turn causes the above-described bonding failure. become.

Further, the inventor of the present invention spends a lot of time on fine adjustment when adjusting the parallelism on the tool side, which hinders improvement of workability in the assembly process using the bonding apparatus. I found a thing.

An object of the present invention is to provide a technique for improving the reliability of bonding when bonding one of the pair of objects to be bonded such as the pellet and the inner lead to the other.

The above and other objects and novel features of the present invention are as follows.
It will be apparent from the description of this specification and the accompanying drawings.

[Means for solving problems]

The outline of a typical invention among the inventions disclosed in the present application will be briefly described as follows.

That is, a pair of objects to be bonded placed on a predetermined position of the support base is clamped between the support base and a pressing member arranged so as to be movable relative to the pair of objects to be bonded. An apparatus for bonding one to the other, characterized in that a deforming member capable of being plastically deformed by a pressing force of a predetermined amount or more of the pressing member is interposed between the base and the support. .

[Action]

According to the above-mentioned means, the support member is previously pressed by the pressing member before the bonding, so that the deformable member interposed between the base member and the support member is plastically deformed. Therefore, even if there is a slight deviation in the parallelism between the support base and the tip of the pressing member, the support base follows the tip of the pressing member due to the plastic deformation, so that the tip of the pressing member is parallel to the support. [Example] FIG. 1 is a sectional view showing a main part of a bonding apparatus according to an embodiment of the present invention, and FIG. 2 is a schematic view of this bonding apparatus. is there.

The bonding apparatus of this embodiment is an inner lead bonder used in an assembly process in manufacturing a semiconductor device, and has the following structure.

That is, as shown in FIG. 2, a rotary table 12 which is rotatable in a horizontal plane is used as a base, and a pair of support bases, which are a pair of support bases, are provided on the base so as to face each other via the center of rotation of the rotary table 12. Stages 10 and 11 are installed, and a bonding stage 1 is provided for each half rotation of the rotary table 12.
0 and 11 are sequentially moved from the positioning position A to the bonding position B.

From the pellet supply device 13 installed adjacent to the rotary table 12, the pellets 2, which are one of the objects to be bonded, are individually supplied via the supply arm 14, and the pellets 11 of the bonding stage 11 placed at the positioning position A are supplied. After being mounted at a predetermined position, the rotary table 12 is rotated to move to the bonding position B.

A tool 7, which is a pressing member, is disposed so as to be able to move up and down directly above the bonding stage 10 at the bonding position B via an elevating arm 9, and its tip is substantially parallel to the bonding stage 10. So that it is fixed to one end of the lifting arm 9.

Further, a tape holder 8 is arranged between the bonding stage 10 and the elevating arm 9 at the bonding position B so that the carrier tape 3 conveyed at a constant speed from a tape supply device (not shown) is held. It has become.

The carrier tape 3 is made of, for example, a polyimide resin film, and an inner lead 4 having a predetermined pattern, which is the other one of the objects to be bonded, is formed on the surface thereof by photolithography or the like.

On the other hand, as shown in FIG. 1, the pair of bonding stages 10 and 11 (only the bonding stage 10 side is shown)
Between the rotary table 12 and the rotary table 12, there is interposed a deformable plate 1 formed of, for example, a mild steel material in the shape of a disk having the same diameter as the bonding stages 10 and 11, and the bonding stage 1
Bonding stages 10, 11 via balls 15 made of a hard material such as steel loaded in holes 6 bored at appropriate positions (two positions are shown in FIG. 1) on the back surface of 0, 11.
It is fixed between the rotary table 12 and the rotary table 12, and plastic deformation is caused by applying a pressing force of a predetermined amount or more to the tool 7.

Next, the operation of the bonding apparatus having the above structure will be described. First, prior to the bonding of the pellet 2 to the inner lead 4, a work of precisely adjusting the parallelism between the tip portion of the tool 7 and the bonding stage 10 in advance is performed. To do. That is, after lowering the tool 7 and bringing its tip end into contact with the bonding stage 10 at the bonding position B, the tool 7 is pressed against the bonding stage 10 with a pressing force that is larger than the pressing force required for bonding. Then, the pressing force is applied to the deformable plate 1 through the balls 15 filled in the holes 6, and then the excessive pressing force causes plastic deformation in the portions of the deformable plate 1 in contact with the balls 15. Is triggered.

Therefore, even if there is a slight deviation in the parallelism between the tip portion of the tool 7 and the bonding stage 10, the plastic deformation causes the bonding stage 10 to follow the tip portion of the tool 7. The parallelism with the stage 10 is adjusted with extremely high accuracy.

Next, the rotary table 12 is rotated half a turn to move the other bonding stage 11 located at the positioning position A to the bonding position B, and similarly the parallelism between the tip of the tool 7 and this bonding stage 11 is precisely adjusted. To do.

Bonding is started after the parallelism is precisely adjusted in the above manner. To explain the process, first,
A bonding stage in which the belt 2 is placed at the positioning position A from the pellet supply device 13 via the supply arm 14.
When individually mounted in the predetermined positions of 10, the rotary table 12 makes a half rotation, moves to the bonding position B, and stops.

On the other hand, when the carrier tape 3 conveyed from the tape supply device to the bonding position B at a constant speed is stopped at a predetermined position, the tool 7 descends so that the pellet 2 and the carrier tape 3 are bonded to the bonding stage 10 and the tool 7. The pressure is applied between the tip and the tool 7, and a voltage is applied to the tool 7 to heat it to a predetermined temperature.
For example, gold (Au) / tin (Sn) protruding from the tips of the plurality of inner leads 4 formed in 16 and the upper surface of the pellet 2.
The plurality of bumps 5 made of a eutectic alloy are bonded by the pressing force of the tool 7 and heat.

At this time, the tip of the tool 7 and the bonding stage
Since the parallelism with 10 is adjusted with extremely high accuracy, the pressing force of the tool 7 is evenly applied to the plurality of bumps 5, thus preventing a problem such as uneven contact of the bumps 5 with respect to the tool 7. To be done.

Next, when the pellet 2 bonded to the inner lead 4 is gradually moved to a position outside the bonding position B by a predetermined pitch after the tool 7 is lifted, the rotary table 12 is rotated a half turn to the positioning position A. While being moved, the bonding stage 11 placed at the positioning position A is moved to the bonding position B, and the series of operations described above are sequentially repeated to continuously bond the pellets 2 to the inner leads 4.

Since the deformation of the deformable plate 1 caused by an excessive pressing force in advance is a plastic deformation, there is no fear of restoring the original shape, and the pressing force applied by the tool 7 at the time of bonding is large. Since it does not deform, the tip of the tool 7 and the bonding stage 10, 11
The parallelism with and is maintained constant in the series of bonding steps.

As described above, the following effects can be obtained in this embodiment.

(1). Prior to the bonding, the tool 7 is pressed against the bonding stages 10 and 11 with an excessive pressing force to cause plastic deformation of the deformable plate 1 interposed between the bonding stages 10 and 11 and the rotary table 12, so that the bonding stage Since 10,11 follows the tip of the tool 7,
The parallelism between the tip of the tool 7 and the bonding stages 10 and 11 is adjusted with extremely high accuracy.

Therefore, since the pressing force of the tool 7 is evenly applied to the plurality of bumps 5 at the time of bonding, defects such as uneven contact of the bumps 5 with respect to the tool 7 are prevented and the reliability of bonding is improved. As a result, the yield of semiconductor devices is also improved.

(2). Compared with the conventional adjustment of the parallelism performed on the tool 7 side, this adjustment work can be performed quickly, so the workability of the bonding process is significantly improved.

Although the invention made by the present inventor has been specifically described based on the embodiments, the present invention is not limited to the embodiments and various modifications can be made without departing from the scope of the invention. Nor.

For example, as the deformable plate 1, not only the above-mentioned mild steel material but also any other material such as other soft metal or synthetic resin that causes plastic deformation with a pressing force larger than the pressing force at the time of bonding can be selected.

Also, as shown in FIG. 3, the bonding stage 1
It is possible to achieve the same effect as that of the present embodiment by adopting a configuration in which an appropriate number of deforming plates 1 are interposed on a part of the back surfaces of 0 and 11, and further, a deforming member having an arbitrary shape is interposed. It is also possible.

In the above description, the invention mainly made by the present inventor has been described as applied to an inner lead bonder used for assembling a semiconductor device which is the field of application of the invention, but the present invention is not limited to this. However, the present invention can be widely applied to a bonding technique in which parallelism between a tool and a bonding stage on which an object to be bonded is placed is important.

〔The invention's effect〕

The effect obtained by the representative one of the inventions disclosed in the present application will be briefly described as follows.

That is, the pressing member is provided between the base and the support at a bonding position formed by the support placed on the base and the pressing member that is arranged so as to be movable relative to the support. By interposing a deformable member that can be plastically deformed by a predetermined pressing force or more, by pressing the support base in advance by this pressing member to cause plastic deformation in the deformable member, the support base follows the pressing member, The parallelism between the pressing member and the support can be adjusted with high accuracy.

Therefore, when a pair of objects to be bonded placed at a predetermined position on the support table is bonded to one of the other objects to be bonded by pinching between the support table and the pressing member, Since the pressing force of the pressing member applied to the object becomes uniform, the reliability at the time of bonding can be improved.

[Brief description of drawings]

FIG. 1 is a sectional view showing a main part of a bonding apparatus according to an embodiment of the present invention, FIG. 2 is a schematic view of this bonding apparatus, and FIG. 3 is another example of a deformable member in this bonding apparatus. FIG. 1 ... Deformation plate (deformation member), 2 ... Semiconductor pellet (bonding object), 3 ... Carrier tape, 4 ... Inner lead (bonding object), 5 ... Bump, 6 ...
Hole, 7 ... Bonding tool (pressing member), 8 ... Tape holder, 9 ... Lifting arm, 10,11 ... Bonding stage (support base), 12 ... Rotating table (base),
13 ... Pellet supply device, 14 ... Supply arm, 15 ... Ball, 16 ... Opening part, A ... Positioning position, B ... Bonding position.

Claims (3)

[Claims] 1. A pair of a support, which comprises a support installed on a base and a pressing member arranged so as to be movable relative to the support, and which is placed at a predetermined position on the support. A device for bonding one of the pair of objects to be bonded to the other by pinching the object to be bonded between the supporting base and the pressing member, which is plastically deformed by a pressing force of a predetermined amount or more of the pressing member. A bonding apparatus, wherein a deformable member that can be deformed is interposed between the base and the support. 2. One of the pair of objects to be bonded is a semiconductor pellet having bumps, the other is an inner lead held by a carrier tape, and the bonding device is an inner lead bonder. The bonding device according to claim 1. 3. The bonding apparatus according to claim 1, wherein the deforming member is a deforming plate made of a mild steel material.