JPH04324950A - Thermocompression bonding head - Google Patents

Abstract

PURPOSE:To enable a large number of leads extending from a semiconductor device to be well bonded by thermocompression even if the substrate is tilted. CONSTITUTION:A thermocompression bonding head is composed of a nozzle 2 which sucks a semiconductor chip P blanked out of a film carrier, a thermocompression bonding piece 6 which is provided by the side of the nozzle 2 in a freely and vertically movable manner so as to bond a lead L which extends from the semiconductor chip P to a board 3, and a heating means 4 which is provided above the thermocompression bonding piece 6 in a freely swingable manner to heat the thermocompression bonding piece 6. The heating means 4 is made to swing following the inclination of the thermocompression bonding piece 6 which comes into contact with the board 3, and the thermocompression bonding piece 6 is pressed against the lead L uniform in pressure to execute thermocompression bonding.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a bonding head for thermocompression, and more particularly to a means for thermocompression bonding a lead extending outward from a semiconductor to a substrate without uneven pressure.

0002

2. Description of the Related Art It is known as the so-called TAB method to form a semiconductor chip by bonding a semiconductor to a film carrier made of synthetic resin such as polyimide and then punching out the film carrier.

[0003] Bonding a semiconductor chip manufactured in this manner to a substrate is generally called outer lead bonding. This outer lead bonding is performed by landing the leads extending outward from the semiconductor onto the electrode portion of the substrate, and pressing a thermocompression bonder onto the leads to bond them by thermocompression.

0004

The upper surface of the substrate on which outer lead bonding is performed as described above is not necessarily a perfectly horizontal surface, but may be an inclined surface due to bending or the like. When the board is tilted like this, pressing the thermocompression bonder against the leads causes uneven pressure, making it difficult to uniformly thermocompress all the leads, which extend in multiple directions from the semiconductor, onto the board. .

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a thermocompression bonding head that can uniformly press and bond leads to a substrate by thermocompression even when the substrate is tilted.

[0006]

[Means for Solving the Problems] The present invention includes a nozzle that sucks a semiconductor chip formed by punching out a film carrier, and a nozzle that is disposed on the side of the nozzle so as to be able to rise and fall freely, and that extends from the semiconductor chip. A thermocompression bonder for thermocompression bonding a lead to a substrate, and a heating means for heating the thermocompression bonder located above the thermocompression bonder, the heating means being swingable relative to the thermocompression bonder. A bonding head for thermocompression is configured.

[0007]

[Operation] In the above structure, the nozzle that has attracted the semiconductor chip descends to land the leads on the substrate. Next, the lead is pressed against the substrate by a thermocompression bonder, and a heating means is further pressed against the thermocompression bonder to bond the lead to the substrate by thermocompression. At this time, if the upper surface of the substrate is inclined, the heating means is inclined along the upper surface of the thermocompression bonder, and the leads are pressed against the substrate with uniform force to thermocompression bond them.

[0008]

【Example】

(Embodiment 1) Next, an embodiment of the present invention will be described with reference to the drawings.

FIG. 1 is a front view of a bonding head for thermocompression. Reference numeral 1 denotes a nozzle shaft, and a nozzle 2 for sucking a semiconductor chip P is attached to the lower end of the nozzle shaft. This semiconductor chip P is formed by the TAB method, and has a large number of leads L extending from the semiconductor C in multiple directions. 3 is a substrate on which the semiconductor chip P is mounted.

Reference numeral 4 denotes a heat block as a heating means provided above the thermocompression bonder 6, and the lower part thereof is a heat transfer section 5.
It becomes. The heat transfer section 5 is brought into contact with and separated from the thermocompression bonder 6 from above, and transfers the heat of the heat block 4 to the thermocompression bonder 6.

The thermocompression bonder 6 is located on the side of the nozzle 2, and
It is provided so as to surround the nozzle 2. The heat block 4 is suspended and supported by a rod 21. 22 is a bracket that holds the rod 21, and 24 is a supporting member further above the bracket. The upper end of the rod 21 is attached to the bracket 2
The rod 21 is loosely fitted into the hole 22a of the rod 21, and a spring material 23 is attached to the rod 21. Therefore, the heat block 4 is slightly swingable in the direction of arrow N. Reference numeral 10 denotes a leaf spring that holds the thermocompression bonder 6, which will be explained next with reference to FIG.

This leaf spring 10 is frame-shaped, and has a rectangular central opening 11. The thermocompression bonder 6 is attached to this opening 11 with screws 12. 13 is a screw hole.

Surrounding this opening 11 are outer slits 14a, 14b and inner slits 15a. 1
5b is formed. Slits 14a, 14b, 15
a and 15b are approximately frame-shaped having components in the X direction and the Y direction, and are formed with tie bar portions 16a, 16b, 17a, and 17b remaining. Tie bar portions 16a and 16b are formed facing each other on the X axis. In addition, the tie bar portion 17a,
17b are formed facing each other on the Y axis.

In this way, the slits 14a to 15 having components in the X and Y directions are formed, leaving the tie bar portions 16a to 17b.
By partially forming b, the leaf spring 10 can be bent in all directions, and the thermocompression bonder 6 held by this leaf spring 10 can be freely tilted in all directions.

In FIG. 1, reference numeral 7 indicates a rod serving as a lifting means that is mounted on the bearing portion 18 so as to be able to move up and down, and 19 is a resilient coil spring. Both ends of the support member 24 are
It is attached to this rod 7. The leaf spring 10 has its outer edge attached to the lower end of the rod 7. Reference numeral 8 indicates a screw for mounting, and reference numeral 9 in FIG. 2 indicates a screw hole. A presser 20 is provided above the rod 7. When the presser 20 is driven up and down by a drive means (not shown), the rod 7 and the heat block 4 and thermocompression bonder 6 supported by the rod 7 are moved up and down.

This bonding head has the above-mentioned structure, and its operation will be explained next.

As shown in FIG. 1, the bonding head with the semiconductor chip P attracted to the nozzle 2 arrives above the substrate 3. As shown in FIG. Next, the nozzle 2 descends and connects the lead L to the substrate 3.
Make it land on top. Next, as the presser 20 descends, the thermocompression bonder 6 presses the lead L against the substrate 3, thereby thermocompression bonding the lead L.

When the substrate 3 is tilted as shown in FIG.
is inclined along the upper surface of the substrate 3. Next, the heat transfer part 5
lands on the top surface of the thermocompression bonder 6, but the thermocompression bonder 6 is attached to the substrate 3.
Since the heat block 4 is tilted along the upper surface, the heat transfer section 5 also swings and tilts along the upper surface of the thermocompression bonder 6, and the lower surface of the heat transfer section 5 is aligned with the upper surface of the thermocompression bonder 6. The leads L, which are tightly fitted and pressure-bonded to the upper surface and therefore extend from the semiconductor C in large numbers in two or four directions, are thermocompression bonded to the substrate 3 without uneven pressure by the heat and pressure received from the thermocompression bonder 6.

[0019] Once the thermocompression bonding is completed in this way,
The nozzle 2 and thermocompression bonder 6 rise. (Embodiment 2) FIG. 4 is a characteristic diagram showing the relationship between the vertical stroke of the heating means 4 and the pressing force against the thermocompression bonder 6. In the figure, A indicates desirable characteristics. Further, B indicates the characteristics of Example 1 above.

When pressing the heating means 4 against the thermocompression bonder 6, it is preferable to press it with a weak force at first and then suddenly increase the pressing force halfway through to press it strongly. For example, the leads L can be firmly bonded to the substrate 3.

However, in the case of the first embodiment, as shown in characteristic B, since the pressing force increases linearly, the lead L
There is a drawback that it is difficult to bond firmly to the board 3. Therefore, next, some means for obtaining characteristic A will be explained.

The one shown in FIG. 5 is equipped with two types of spring materials 23a and 23b having different spring constants. By combining a plurality of spring materials in this way, the characteristic A described above can be obtained.

In the device shown in FIG. 6, magnets 26 and 27 are attached to the bracket 22 and the heat block 4 so as to face each other. These magnets 26 and 27 have the same polarity, and the closer they are to each other, the more they repel each other. Therefore, as the heat transfer portion 5 lands on the thermocompression bonder 6 and the distance between the magnets 26 and 27 becomes shorter, the mutual repulsive forces rapidly increase, so that the characteristic A described above is obtained. In this way, various means can be considered for rapidly increasing the pressing force of the heat block 4.

(Embodiment 3) It is desirable that the thermocompression bonder 6 be pressed with an even force to the leads L extending from the semiconductor C in four or two directions. can be evenly bonded to the substrate 3 by pressing it evenly.

FIG. 7 shows a means for solving such a technical problem. The heat block 4 is suspended and held by the bracket 22 via a plurality of cylinders 30. Since the rods 31 of the cylinders 30 protrude and retract due to fluid pressure, the force of each cylinder 30 is constant even if the amount of protrusion of each rod 31 varies.

Therefore, following the inclination of the thermocompression bonder 6,
Even if the heat block 4 is tilted as shown by the chain line and the rod 31 is protruded and retracted accordingly, each cylinder 30
The force is always constant, and the leads L extending in two or four directions can be pressed against the substrate 3 with uniform force.

[0027]

As explained above, the present invention includes a nozzle for sucking a semiconductor chip formed by punching out a film carrier, and a nozzle disposed on the side of the nozzle so as to be able to rise and fall freely.
A thermocompression bonder for thermocompression bonding the leads extending from the semiconductor chip to the substrate, and a heating means disposed above the thermocompression bonder for heating the thermocompression bonder, the heating means being connected to the thermocompression bonder. If the board is tilted, the heating means can be tilted along the top surface of the thermocompression bonder, and the leads can be pressed against the board with even force for thermocompression bonding. can.

[Brief explanation of drawings]

FIG. 1 is a front view of a bonding head according to the present invention.

[Fig. 2] A plan view of a leaf spring according to the present invention.

[Fig. 3] Front view during bonding according to the present invention

[Figure 4]
Characteristic diagram of pressing force according to the present invention

[Fig. 5] Front view of main parts according to another embodiment of the present invention

[Figure 6]
A front view of main parts according to still another embodiment of the present invention

FIG. 7 is a front view of main parts according to still another embodiment of the present invention.

[Explanation of symbols]

2 Nozzle 3 Board 4 Heating means 6　Thermocompression bonder

Claims (1)

[Claims] Claims 1: A nozzle for adsorbing a semiconductor chip formed by punching a film carrier, and a nozzle disposed on the side of the nozzle so as to be able to rise and fall freely, and for bonding leads extending from the semiconductor chip to a substrate by thermocompression. It is characterized by comprising a thermocompression bonder and a heating means for heating the thermocompression bonder, which is located above the thermocompression bonder, and the heating means is provided to be swingable with respect to the thermocompression bonder. Bonding head for thermocompression.