JPH0238451Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Field of Industrial Application) The present invention relates to improvements in tools used in tape bonding.

(Prior Art) As is well known, there are two types of bonding methods for tape bonding: inner lead bonding and outer lead bonding.

Inner lead bonding is the process of bonding the bumps (workpiece joints) of an IC element (IC chip) and the leads on the carrier tape.
On the other hand, outer lead bonding is a process in which an IC element with leads is punched out from a carrier tape in a subsequent process, and then the leads (joint part of the workpiece) are bonded to a lead frame or wiring board. Hereinafter, for convenience of explanation, inner lead bonding will be explained as an example.

FIG. 3 shows an operational diagram of general inner lead bonding. In the figure, a bonding pedestal 1 placed at the bonding station position has an IC element (IC chip) as a workpiece.
Further, the inner lead 3 of the carrier tape is placed on the joint portion of the IC element 2 (hereinafter referred to as the work joint portion).

On the other hand, a tool 4 is attached to the bonding head of a bonding device (not shown) so as to be able to move up and down, and as the tool 4 is lowered, the inner lead 3 and the workpiece joint are pressurized with each other as shown in the figure. state. In this pressurized state, by passing a current through the tool 4, the pressurizing part 4a of the tool 4 generates heat due to the electric resistance of the tool 4 itself.
The bonding surface between the workpiece bonding portion and the inner lead 3 is melted. Immediately after this melting, the power supply to the tool 4 is stopped and air is blown around the joint from the outer cooling nozzle 5 to cool and solidify the melted part, thereby forming the desired joint between the inner lead 3 and the workpiece. A bonding of the two is achieved.

(Problem to be solved by the invention) However, when bonding is performed using the conventional tool 4 described above, after the workpiece joint and the inner lead 3 are melted, the joint is held down by the tool 4 in a high temperature state. Since this method cools the joint by blowing air over the joint, local rapid cooling of the joint causes heat deviation in the joint, and this heat deviation causes unevenness in the metal structure, which reduces the joint strength. There is a problem in that it becomes unstable and the reliability of the bond cannot be obtained.

Further, as described above, since the bonding part is cooled while being held by the hot tool 4, it takes a long time to cool down the bonded part, which is disadvantageous in that it is not possible to speed up the bonding work.

The present invention was developed to solve the above-mentioned conventional problems, and its purpose is to enable uniform and rapid cooling of the bonded part, improve yield in IC production, improve reliability in bonding, and improve productivity. The object of the present invention is to provide a tape bonding tool that can significantly improve the properties of each tape bonding tool.

(Means for solving the problems) In order to achieve the above object, the present invention is constructed as follows. That is, the present invention includes a heating current introducing section; a pressure section that presses the workpiece joint to the lead; and heats the pressure section using the energy of the heating current to thermally fuse the workpiece joint and the lead. In the tape bonding tool, cooling flow holes are provided inside the pressurizing section to supply cooling fluid to the workpiece bonding section from inside the pressurizing section.

(Function) In the present invention having the above configuration, the workpiece joint and the lead are joined together by keeping the workpiece joint and the lead in pressure contact with a tool and supplying current to the tool, as in the conventional example. This is done by In the present invention, cooling of the joint surface between the workpiece joint and the lead after melting is performed by blowing air from outside using a cooling nozzle, and cooling fluid is supplied to the cooling circulation hole of the tool to cool the joint surface between the workpiece joint and the lead. This is done by squirting cooling fluid from inside the pressurized part. By simultaneously cooling the joint from both the inside and outside, substantially uniform and rapid cooling of the joint can be achieved.

(Example) Hereinafter, an example of the present invention will be described based on the drawings. FIG. 1 shows the configuration of an embodiment of the present invention, and FIG. 2 shows a usage state of the tool in this embodiment.

In the figure, the tool 4 has a heating current introducing section 4b and a pressing section 4a. A recess 6 is formed in the end surface of the pressurizing part 4a, and a through hole 7 is bored in each side wall of the recess 6.

Then, a slit 16 is made from the inside of the through hole 7 on the front side and the back side to the base end 15 of the tool 4, and the tool 4 is divided into two parts, leaving the tip wall 17. The cross-sectional area of this tip wall 17 is sufficiently smaller than the cross-sectional area of the current introducing portion 4b, and therefore the tip wall 17 becomes a portion of increasing electrical resistance, and the current introducing portion 4b
By supplying current from
The pressurizing portion 4a generates heat due to the electrical resistance of the tip wall 17 itself (particularly the tip wall 17).

Further, in the center of the tool 4, a characteristic cooling hole 8 penetrating from the base end 15 to the pressurizing part 4a is provided.
is provided. Since the cooling circulation hole 8 is provided along the cutout 16, the cooling circulation hole 8
Although the slits 16 are in communication with each other, the surface portions of the slits 16 are sealed with an insulating resin in order to make the cooling flow holes 8 airtight.

The tool 4 of this embodiment is constructed as described above, but when the tool 4 is installed in the bonding head of a bonding device, as shown in FIG. 2, the tool 4, the tool holding electrode 9, The electrode holding fitting 10 is fixed integrally with the electrode holding fitting 10.
is attached to the bonding head. That is, an engagement recess is provided in the lower half of the tool holding electrode 9, and the tool 4 is fitted into this engagement recess. Similarly, the electrode holding fitting 10
An engagement recess is also formed in the engagement recess, and the tool holding electrode 9 is fitted into this engagement recess.

In this case, a slit 16 is provided in the center of the electrode holding fitting 10 and the tool holding fitting 9, so that the electrode holding fitting 10 and the tool holding fitting 9 are divided into left and right halves. And this cut 1
The surface portion of 6 is filled with an insulating resin, and the opening of the cut 16 is closed and the left and right parts divided into two parts are bonded together. That is, although the electrode holding fitting 10 and the tool holding fitting 9 are electrically divided into two parts by the cut 16, since both the left and right members are bonded with insulating resin, they are mechanically constructed as one piece. It will be done. The tool 4, tool holding electrode 9, and electrode holding fitting 10 that are fitted into each other are integrally fixed by screws 18, and are connected to the bonding head of the electrode holding fitting 10 via an insulating member (not shown). Installation will take place.

By the way, the tool holding electrode 9 and the electrode holding fitting 10 are provided with communication holes 11 and 12 coaxially with the cooling circulation holes, and the communication holes 1 and 12 are provided from the outside.
By introducing a cooling gas (cooling fluid) such as nitrogen into 2, this cooling gas is ejected from the outlet of the cooling circulation hole 8 into the pressurizing part 4a through the communication hole 11. Further, power cables 13 and 14 are bolted to the tool holding electrode 9, and heating current is supplied to the tool 4 from a power source (not shown) via the power cables 13 and 14. .

The present embodiment has the above configuration, and its operation will be explained below. First, when bonding the workpiece bonding portion and the inner lead 3, the bonding head is lowered and the workpiece bonding portion and the inner lead 3 are kept in pressure contact with each other by the tool 4, as in the conventional example. Next, a heating current is supplied from the power source to the tool holding electrode 9 via the power cables 13 and 14.

This heating current flows into the tool 4 through the introduction part 4b, and heat is generated in the pressurizing part 4a. The joint surface between the workpiece joint and the inner lead 3 melts due to the heat generated by the pressurizing part 4a, but immediately after this melting, the supply of heating current is cut off, and at the same time, cooling nitrogen gas is introduced into the communication hole 12. , the cooling nitrogen gas is blown out from the cooling flow holes 8 to cool the joint from the inside.

On the other hand, similarly to the conventional example, cooling air is blown from the cooling nozzle 5 to cool the joint from the outside as well. In this way, by cooling the joint from both the inside and outside, it is possible to cool the joint almost uniformly, and the metal structure of the joint can be made uniform, resulting in a stable bond with extremely strong bonding strength. can get.

In addition, since the joint can be cooled from both the inside and outside,
Cooling time can be shortened, thereby making it possible to speed up bonding work.

Furthermore, cooling nitrogen gas can be supplied through the cooling circulation holes 8 inside the tool 4, and if particularly necessary, it is also possible to constantly flow a small amount of cooling nitrogen gas. In addition to preventing oxidation of the tool 4, overheating of the tool 4 is prevented, and the tool life can be significantly extended.

(Effects of the invention) Since the present invention has the configuration and operation as explained above, when joining workpieces, the joint part can be cooled not only from the outside but also from the inside of the pressurizing part. This makes it possible to cool the bonded area uniformly and quickly, making it possible to achieve stable bonding with strong bonding strength in a short time, which improves yield in IC production, reliability in bonding, and productivity. It is possible to achieve this significantly.

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing the configuration of an embodiment of the present invention, FIG. 2 is a diagram showing how the tool is used in this embodiment, and FIG. 3 is an explanatory diagram of the operation of a conventional tool. 1...Bonding pedestal, 2...IC element, 3
...Inner lead, 4...Tool, 4a...Pressure section, 4b...Introduction section, 5...Cooling nozzle, 6...
... recess, 7 ... through hole, 8 ... cooling circulation hole, 9 ...
Tool holding electrode, 10... Electrode holding fitting, 11,
12... Communication hole, 13, 14... Power cable,
15...Proximal end, 16...Cut, 17...Distal wall, 18...Screw.

Claims (1)

[Scope of utility model registration request] In a tape bonding tool that is equipped with a current introduction part for heating current; a pressure part that presses the workpiece joint to the lead; and heats the pressure part with the energy of the heating current to thermally fuse the workpiece joint and the lead. . A tape bonding tool, characterized in that the pressurizing section is provided with a cooling flow hole for supplying cooling fluid from the inside of the pressurizing section to the workpiece bonding section.