JPH01316944A - Wire bonding - Google Patents

Abstract

PURPOSE:To shorten the time of index necessary for wire bonding by a method wherein the pellet on the uppermost step in a cassette, in which semiconductor elements are housed in a stacked state, is directly wire-bonded on a lead frame conveyed to the upper part of the cassette. CONSTITUTION:A housing cassette 1, in which semiconductor elements 3 are stacked and housed, is fixed. The elements 3 are heated in a state that they are housed in the cassette 1. A semiconductor element 3' on the uppermost step in the cassette 1 is held and fixed in a prescribed height. An electrode part 8 on the element 3' and internal connecting parts of an island-free lead frame are connected to each other by fine metal wires. Whereupon, as there is no need to convey and place the elements 3, the time of index to need for wire bonding is shortened.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a wire bonding method, and particularly to a method for supplying semiconductor elements when using a lead frame with a semiconductor element mounting portion (hereinafter referred to as an island). and a holding method.

[Conventional technology]

Conventionally, wire bonding methods using lead frames without islands have been as follows. That is,
A lead frame without an island, automatic feeding and positioning means for the lead frame, heating means for a wire bonding site, a heating block heated by the heating means, and holding and fixing means for holding a semiconductor element on the heating block; It has a supply means for supplying the semiconductor element onto the heating block, and a recognition control means for automatically recognizing the amount of positional deviation between the semiconductor element supplied on the heating block and the internal connection part of the lead frame without an island. . Further, the means for supplying the semiconductor element onto the heating block includes means for holding a resin sheet to which the semiconductor element is attached;
A means for automatically recognizing the position of a semiconductor element affixed to a resin sheet, a means for adsorbing and holding a semiconductor element affixed to a resin sheet, and placing it on a heating block; It has means for holding and fixing the semiconductor element.

In the above configuration, the unfinished wire bonding portion of the island-less lead frame is transferred and positioned to the wire bonding site of the heating block, and the semiconductor element stuck on the resin sheet is attracted and held. The semiconductor element is held by a means for holding the semiconductor element placed on the heating block, and is then conveyed and placed at a predetermined position on the heating block. Correct the positional deviation,
The conventional method was to wire-bond the electrodes of the semiconductor element and the internal connections.

[Problem to be solved by the invention]

In the conventional wire bonding method described above, when the semiconductor element pasted on the resin sheet is fed to a predetermined position on the heating block, the semiconductor element on the resin sheet is automatically recognized, and the recognized semiconductor element is placed on a fret or the like. The semiconductor device is picked up by a jig and transferred to a predetermined position on the heating block, and then the semiconductor device is lowered and placed in a predetermined position on the heating block. This method has the disadvantage that the indexing time required for wire bonding is longer than that of the bonding method.

In the conventional wire bonding method described above, in which a semiconductor element and a lead frame without an island are connected using thin metal wires, the semiconductor element pasted onto a resin sheet is adsorbed using a jig such as a collet, and then placed in a predetermined position on a heating block. In contrast to the conventional method, in which semiconductor devices are transported and placed in a position and fixed using means such as vacuum suction, the present invention is capable of transferring the topmost pellet of a cassette containing stacked semiconductor devices to the top of the cassette. The difference is that wire bonding is performed directly to the transported lead frame.

[Means to solve the problem]

The wire bonding method of the present invention is a wire bonding method in which a semiconductor element and a lead frame without an island are connected with a thin metal wire. This method involves wire bonding directly to the lead frame.

〔Example〕

Next, the present invention will be explained with reference to the drawings.

FIG. 1 is an explanatory diagram illustrating an embodiment of the present invention.

As shown in FIG. 1, a heating block 5 is mounted on a heating block stage 7 that moves vertically. The heating block stage 7 and the heating block 5 have mounting holes for the semiconductor element storage cassette 1, and the storage cassette 1, in which the semiconductor elements 3 are stacked and stored, is fixed. The mounting hole has a size that makes contact with the outer wall of the storage cassette 1, and the semiconductor element 3 is heated by the heating block 5 while it is housed in the storage cassette 1. Further, the heating block stage 7 has a pushing rod 2 for holding and supplying the semiconductor element 3 in the storage cassette 1, and the pushing rod 2 is used to hold and supply the semiconductor element 3 in the storage cassette l. In this structure, the heating block stage 7 is lowered, and the unbonded part of the lead frame without an island is positioned and supplied by the supply means.Next, the heating block stage 7 7 is raised, the internal connection part of the lead frame without an island is brought into close contact with the heating block 5, the internal connection part is fixed, and heated.

At the same time, the pushing rod 2 is raised to hold and fix the uppermost semiconductor element 3' in the semiconductor element storage cassette 1 at a predetermined height. Next, the electrode portion 8 on the semiconductor element 3' and the internal connection portion of the lead frame without an island are connected by a thin metal wire.

When the connection of the semiconductor element 3' is completed, the heating block stage 7 is lowered, and then the portion of the lead frame where wire bonding has not been completed is supplied by the supply means, and the above-described method is repeated.

According to such a method, since there is no need to transport and place the semiconductor element, the index time required for wire bonding can be shortened by about 0.45 to 1.3 seconds.

FIG. 2 is an explanatory view of the operation of Example 20 of the present invention.

As shown in FIG. 2, a heating block 5 is mounted on a heating block stage 7 that moves vertically. The heating block stage 7 and the heating block 5 are provided with mounting holes for semiconductor element storage cassettes.
Stack them to store them and fix the storage cassette. The mounting hole contacts the outer wall of the storage cassette 1 in the heating block stage 7, and fixes the storage cassette 1. The mounting hole of storage cassette 1 of heating block 5 is
There is no contact with the outer wall, which means no heat conduction occurs. The heating block stage 7 also has a pushing rod 2' for holding and supplying the semiconductor element 3 in the storage cassette 1. It has a structure in which it pushes up from the bottom of the element 3''. The pushing rod 2 also serves as a heater and heats the semiconductor element 3.

In such a structure, by performing wire bonding, the electrode 8 on the semiconductor element and the internal connection part of the lead frame are heated independently, so when replacing the semiconductor element storage cassette 1, the heat capacity is small. Heating and cooling can be easily performed, and the indexing time required for wire bonding work can be shortened, and the same effects as in the first embodiment can be obtained.

〔Effect of the invention〕

As explained above, according to the present invention, by directly wire-bonding the semiconductor element in the uppermost stage of a cassette in which semiconductor elements are stored in a stacked state to the lead frame without an island conveyed to the upper part of the cassette,
This has the effect of reducing the index time required for wire bonding and reducing costs.

[Brief explanation of the drawing]

FIG. 1 is an operational explanatory diagram for explaining one embodiment of the present invention, and FIG. 2 is an operational explanatory diagram for explaining a second embodiment of the present invention. 1... Semiconductor element storage cassette, 2...
・Extrusion rod, 2'... Extrusion rod with heating function, 3... Semiconductor element, 3'...
Semiconductor element located at the top level in the semiconductor element storage cassette, 3''... Semiconductor element located at the bottom level in the semiconductor element storage cassette, 4... Internal connection of lead frame without island Part 5: Heating block, 6: Fine metal wire, 7: Heating block stage, 8: Electrode. Agent: Susumu Uchihara, patent attorney Figure 1, Figure 1032.

Claims (1)

[Claims] In a wire bonding method in which a semiconductor element and a lead frame without a semiconductor element mounting part are connected with a thin metal wire, the uppermost pellet of a cassette containing stacked semiconductor elements is directly wired to the lead frame conveyed to the upper part of the cassette. Characterized by bonding,
Wire bonding method.