JPH07201933A - Bonding tools - Google Patents

Abstract

(57) [Abstract] [Purpose] To provide a bonding tool capable of performing reliable crimping even if the holding block thermally expands. A bonding tool 1 for connecting a plurality of leads 11 extending in a direction substantially perpendicular to a side of a semiconductor element 10 and a wiring pattern 21 provided on a substrate 20. A thermocompression-bonding portion which is formed by arranging a plurality of heating members 2 which are pressed and heated at a predetermined temperature in a direction substantially parallel to the sides of the semiconductor element 10 and which has a predetermined gap 2a between adjacent heating members 2. 3 and a holding block 4 for holding each heating member 2 of the thermocompression bonding unit 3,
The gap 2 a between the adjacent heating members 2 is provided obliquely to the extending direction of the lead 11.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a bonding tool for connecting leads extending from a semiconductor element to a wiring pattern provided on a substrate.

[0002]

2. Description of the Related Art From the viewpoint of making electronic devices thin and compact, a TAB package has been considered which can be mounted on a substrate without encapsulating a semiconductor element with a resin or the like. Figure 3 is TA
It is a figure explaining the manufacturing method of B package, (a)-
It is manufactured in the order shown in (d).

That is, first, in the inner lead bonding step shown in FIG. 3A, the chip-shaped semiconductor element 10 is electrically and mechanically connected to the lead 11 made of copper foil or the like formed on the film tape 5. . The film tape 5 is made of a resin such as polyimide formed in a long shape with a predetermined width, and is capable of connecting a plurality of semiconductor elements 10 continuously in the longitudinal direction. The semiconductor element 10 is provided with electrode pads (not shown) for inputting / outputting signals to / from an internal circuit, and the leads 11 provided on the film tape 5 and the electrode pads are, for example, bumps (not shown). ) Is connected via. Thereby, the semiconductor element 10 and the lead 11 are electrically and mechanically connected.

Next, as a cutting step shown in FIG.
The lead 11 is cut around the semiconductor element 10 connected to the film tape 5 to divide into individual semiconductor elements 10. After this cutting is completed, as a forming step shown in FIG. 3C, the leads 11 extending outward from the semiconductor element 10 are bent into a predetermined shape. That is, the leads 11 are pressed so that the semiconductor element 10 has a shape (eg, gull wing type) that facilitates mounting on the substrate (not shown). After the pressing of the leads 11 is completed, the film tape (see FIG. 3C) attached to the tip portions of the leads 11 is cut as a film tape cutting step shown in FIG. 3D. This allows TAB
The manufacture of the semiconductor device 10 including the package is completed.

In order to mount the semiconductor element 10 composed of such a TAB package on a substrate, connection by thermocompression bonding using a bonding tool is performed. In recent years, the size of the semiconductor element 10 has increased along with the high integration of the internal circuit, and a large-sized bonding tool is required for mounting the semiconductor element 10 composed of a TAB package.

In this large-sized bonding tool, the leads 11 of the semiconductor element 10 are thermocompression-bonded onto the substrate, so that a press-contact surface having a large area is required, but it is necessary to maintain a large flat press-contact surface with high flatness. Have difficulty. Therefore,
A bonding tool 1 as shown in FIG. 4 is considered. That is, as shown in the perspective view of FIG. 4A, the bonding tool 1 has a plurality of heating members including thermocompression bonding portions 3 for thermocompression bonding the leads 11 of the semiconductor element 10 to the wiring patterns 21 provided on the substrate 20. It is composed of two.

The plurality of heating members 2 are held by a holding block 4, and an electric current flows through each of them to instantly reach a predetermined temperature. For example, the semiconductor device 1
Corresponding to the plurality of leads 11 extending from one side of 0, several (3 in FIG. 4) heating members 2 are arranged in a direction substantially parallel to the side. When the leads 11 extend from the four sides of the semiconductor element 10, a plurality of heating members 2 are arranged corresponding to the respective sides and the thermocompression bonding portion 3 is provided.
Make up.

Since the thermocompression bonding portion 3 is composed of the plurality of heating members 2 in this manner, a high flatness can be easily achieved on the pressure contact surfaces of the individual heating members 2, so that the thermocompression bonding portion 3 can be formed easily. Higher flatness can be achieved as a whole. FIG. 4B is a schematic plan view illustrating the contact positional relationship between each heating member 2 and the lead 11. The plurality of heating members 2 are arranged in a direction substantially parallel to the sides of the semiconductor element 10, and a predetermined gap 2b is provided between them.

For example, the width of the lead 11 is 80 μm to 10 μm.
In the case of about 0 μm, a gap 2b of about 50 μm is provided. That is, if the width of the gap 2b is made smaller than the width of the lead 11, the leads 11 can be formed by the plurality of heating members 2.
Even when the position of the gap 2b and the position of the lead 11 overlap each other when pressing, the lead 11 can be pressed by any one of the heating members 2.

In order to mount the semiconductor element 10 using the bonding tool 1, first, the semiconductor element 10 is mounted on the substrate with the lead 11 of the semiconductor element 10 and the wiring pattern 21 on the substrate 20 aligned. Place on top of 20. In this state, the contact portion between the lead 11 and the wiring pattern 21 is pressed by the thermocompression bonding portion 3 of the bonding tool 1, and an electric current is passed through each heating member 2 to heat the contact portion. As a result, the lead 11 and the wiring pattern 21 are thermocompression bonded, and the semiconductor element 10 can be mounted on the substrate 20.

[0011]

However, such a bonding tool has the following problems. FIG. 5 is a schematic diagram for explaining a change in a conventional gap, (a)
Shows a normal state, and (b) shows a case of a thermal expansion state. That is, as shown in FIG. 5A, in a normal state, the gap 2b provided between the adjacent heating members 2 is formed.
Since the width of is smaller than the width of the lead 11, the heating member 2 can press the lead 11 even if the positions of the gap 2b and the lead 11 overlap.

However, as shown in FIG. 5B, when the holding block 4 (see FIG. 4) is thermally expanded by the heating of the heating member 2, as a result of the thermal expansion, the space between the adjacent heating members 2 is increased. Thus, the gap 2b provided at is widened. When the width of the gap 2b becomes larger than the width of the lead 11 due to the thermal expansion of the holding block 4 (see FIG. 4), when the position of the gap 2b and the position of the lead 11 overlap, the lead 11 falls within the gap 2b. Lead into the lead 11
Can no longer be pressed.

Further, even if the lead 11 does not enter the gap 2b, a sufficient pressing force against the lead 11 cannot be obtained, which causes a crimping failure. Therefore, an object of the present invention is to provide a bonding tool capable of performing reliable pressure bonding even if the holding block thermally expands.

[0014]

SUMMARY OF THE INVENTION The present invention is a bonding tool made to solve such problems. That is, this bonding tool is a tool for connecting a plurality of leads extending in a direction substantially perpendicular to the sides of a semiconductor element formed of a substantially quadrangle and a wiring pattern provided on a substrate. A thermocompression-bonding portion, which is formed by arranging a plurality of heating members for pressing and heating at a predetermined temperature in a direction substantially parallel to the sides of the semiconductor element and having a predetermined gap between adjacent heating members; A holding block for holding each heating member of the thermocompression bonding portion is provided, and the gap between adjacent heating members is oblique to the extending direction of the leads.

[0015]

In the bonding tool of the present invention, the thermocompression bonding portion is composed of a plurality of heating members, and the gap between the adjacent heating members is provided obliquely with respect to the extending direction of the leads. Even if the gap widens, the leads will not enter the gap. That is, since the direction of the gap and the direction of the lead do not coincide with each other, the lead can be pressed by one of the heating members even if the gap is somewhat widened.

[0016]

Embodiments of the bonding tool of the present invention will be described below with reference to the drawings. 1A and 1B are views for explaining a bonding tool of the present invention. FIG. 1A is a perspective view and FIG. 1B is a schematic plan view. That is, as shown in FIG. 1A, in the bonding tool 1 of the present invention, when mounting the semiconductor element 10 formed of, for example, a TAB package (see FIG. 3) on the substrate 20, the leads 11 extending from the semiconductor element 10 are mounted. Is for thermocompression bonding to the wiring pattern 21 provided on the substrate 20.

The bonding tool 1 comprises a thermocompression bonding portion 3 composed of a plurality of heating members 2 for pressing the leads 11 and heating them at a predetermined temperature, and a holding block 4 for holding each heating member 2 of the thermocompression bonding portion 3. It consists of and. The heating member 2 is made of a material having a relatively small thermal expansion coefficient, and has a structure in which it is instantly heated by a predetermined current. Further, the lower surface is a pressure contact surface finished with high flatness.

As shown in FIG. 1B, the plurality of heating members 2 are arranged in a direction substantially parallel to the sides of the semiconductor element 10, and a predetermined gap 2a is provided between adjacent heating members 2. It is provided. For example, when the leads 11 extend from all four sides of the semiconductor element 10, a plurality of heating members 2 (three in one side in FIG. 1) are arranged corresponding to each side. Further, the gaps 2 a between the plurality of heating members 2 in the bonding tool 1 are provided so as to be oblique with respect to the direction of the leads 11 extending from the semiconductor element 10.

That is, the extending direction of the lead 11 and the gap 2
Since the direction of a does not match, when the lead 11 is pressed by the thermocompression bonding portion 3, the lead 11 overlapping the position of the gap 2a is obliquely seen in plan view by the heating members 2 on both sides of the gap 2a. Will be pressed by.

In order to mount the semiconductor element 10 using this bonding tool 1, first, the semiconductor element 10 is suction-held by using a suction nozzle (not shown) provided in the bonding tool 1, and transferred onto the substrate 20. Then, the leads 11 of the semiconductor element 10 and the wiring pattern 21 on the substrate 20
Align with. With the semiconductor element 10 aligned, the lead 11 and the wiring pattern 21 are brought into contact with each other,
An electric current is applied to each heating member 2 constituting the thermocompression bonding portion 3 of the bonding tool 1 to heat it to a predetermined temperature. Then, the contact portion between the lead 11 and the wiring pattern 21 is pressed by the lower surface (pressure contact surface) of each heating member 2 finished to have high flatness, and thermocompression bonding is performed. As a result, the semiconductor element 10 is mounted on the substrate 20.

During thermocompression bonding using such a bonding tool 1, the heating member 2 is heated and the holding block 4 thermally expands. FIG. 2 shows a holding block 4 (see FIG. 1).
FIG. 6 is a schematic diagram illustrating a change in the gap 2a when the heat expands.

That is, as shown in FIG. 2A, in a normal state (state before thermal expansion), the gap 2a provided between the adjacent heating members 2 is arranged in the extending direction of the leads 11. It is oblique, and the end portion of the heating member 2 is in contact with the lead 11 obliquely in a plan view.

On the other hand, as shown in FIG. 2B, when the holding block 4 (see FIG. 1) is thermally expanded, the adjacent heating members 2 are in a direction substantially perpendicular to the extending direction of the leads 11. (See the arrow in the figure), the gap 2a also expands in the same direction. However, even if the width of the gap 2a is widened, the gap 2a is inclined with respect to the extending direction of the lead 11, so that at least one of the heating members 2 on both sides of the gap 2a has an end portion of the heating member 2. The lead 11 can be pressed. That is, even if the positions of the gap 2a and the lead 11 overlap, the lead 11 does not enter the gap 2a, and the heating member 2 can reliably press the lead 11.

By thus forming the gap 2a obliquely with respect to the extending direction of the lead 11, even if the holding block 4 (see FIG. 1) is thermally expanded and the gap 2a is widened, the lead 11 is formed.
No more defective crimping. Note that the diagonal gap 2
By increasing the angle of “a” with respect to the extending direction of the lead 11 as much as possible, it is possible to cope with the widening of the large gap 2a.

Further, in this embodiment, the semiconductor device 10 is used.
Although the example in which the three heating members 2 are arranged on one side has been described, the present invention is not limited to this, and the same is true regardless of how many heating members 2 are arranged on one side. . Further, although the case where the semiconductor element 10 composed of the TAB package is mounted is described in the present embodiment, the same applies to the case where the semiconductor element 10 is mounted by thermocompression bonding the lead 11 and the wiring pattern 21 in addition to this. Is.

[0026]

As described above, the bonding tool of the present invention has the following effects. That is,
Even if the gap provided between the adjacent heating members is expanded due to the thermal expansion of the holding block, the leads can be sufficiently pressed, and the leads of the semiconductor element and the wiring pattern on the substrate It becomes possible to perform the thermocompression bonding with certainty. That is, even with a bonding tool in which a thermocompression bonding portion is composed of a plurality of heating members, a sufficient pressing force can be applied to the leads. It is possible to connect the leads evenly and surely.

[Brief description of drawings]

FIG. 1 is a diagram illustrating a bonding tool of the present invention,
(A) is a perspective view and (b) is a schematic plan view.

2A and 2B are schematic diagrams for explaining changes in a gap, in which FIG. 2A shows a normal state and FIG. 2B shows a thermal expansion state.

3A and 3B are diagrams illustrating a TAB package, in which FIG. 3A is an inner lead bonding step, FIG.
(C) shows a forming process and (d) shows a film tape cutting process.

FIG. 4 is a diagram illustrating a conventional bonding tool,
(A) is a perspective view and (b) is a schematic plan view.

FIG. 5 is a schematic diagram illustrating a change in a conventional gap, (a)
Shows a normal state and (b) shows a thermal expansion state.

[Explanation of symbols]

 1 Bonding Tool 2 Heating Member 2a Gap 3 Thermocompression Bonding Part 4 Holding Block 10 Semiconductor Element 11 Lead 20 Substrate 21 Wiring Pattern

Claims (1)

[Claims] 1. A bonding tool for connecting a plurality of leads extending in a direction substantially perpendicular to a side of a semiconductor element formed of a substantially quadrangle and a wiring pattern provided on a substrate, said bonding tool comprising: Thermocompression bonding in which a plurality of heating members for pressing the leads and heating them at a predetermined temperature are arranged in a direction substantially parallel to the sides of the semiconductor element, and a predetermined gap is provided between adjacent heating members. And a holding block for holding each heating member of the thermocompression bonding unit, and a gap between the adjacent heating members is oblique with respect to the extending direction of the lead. Bonding tool.