JPS6028386B2 - Lead frame placement method inside the mold - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention is directed to a technique for arranging a filling material in a resin mold, and particularly to a resin molding apparatus used in an assembly apparatus for semiconductor devices.

When assembling a resin-sealed semiconductor device, multiple elements of the same type are formed and processed at the semiconductor wafer stage, and the wafer is divided into pellets containing each element by scribing.
Prepare a continuum of a lead frame in which a plurality of leads are integrally formed, bond a pellet onto this lead frame, perform wire bonding between the electrodes of the pellet and the leads, and then bond the lead frame onto the lead frame. The let is sealed with resin. Previously, a dedicated automatic machine was used for each of these processes, and each time one process was completed, it was transferred to and set on the next process's automatic machine, but this reduces the work effort and loss of set time caused by this. Automatic assembly methods are being adopted for this purpose. As an assembly device for this purpose, a frame transfer mechanism is used that cuts the lead frame from a continuous body into regular lengths or intermittently feeds the lead frame as a composite lead frame, and for example, performs pellet ponding and fabrication along two transfer lines.
The applicant has developed a device in which a wire bonding diamond layer, preheating and resin molding devices are arranged, and assembly and sealing operations are performed consistently in this order. When using conventional resin molding, lead flake occurs inside the mold.
When arranging the frames, for example, as shown in Fig. 1, a relatively short lead frame complex of 7 to 1
A plurality of sets of two rows of lbs facing each other with runners 2 arranged between them were arranged along the mating surface 4 of the mold 4 with the resin-injected cull 8 at the center.

When four sets are arranged as shown in the figure, the total number of ICs molded in one shot is 56 to 80. When performing resin molding using such a conventional arrangement method, there are the following problems. That is, in order to set a large number of lead frame composites at predetermined positions in a mold, an alignment pick 5 having the same shape as the mating surface of the mold is prepared in advance as shown in FIG. Lead frame composites la, l in predetermined positions and corresponding arrangements
Perform alignment as shown in b, move this alignment jig between the upper and lower molds, transfer it to one side of the mold (loading), close the upper and lower molds and perform molding, and after molding, remove the alignment jig from the mold. It is necessary to carry out unloading, alignment, and transfer of each lead frame composite to arrange it as required for the next process.

An automatic alignment positioning device for the lead frame complex to automate the setting and removal of the frame using such an alignment tool, an automatic movement of the lead frame into the aligned odor control mold, a loading device, and a mold. Providing an automatic unloading device for later molds and an automatic alignment device for stacking frames from pick-up tools inevitably increases the equipment cost. The present invention has been made to solve these problems, and its purpose is to provide a technique for arranging an IJ frame in a mold for a molding device at low equipment costs.

In order to achieve the above object, the present invention arranges a long continuous gluing frame fixed length composite in two rows across the cull part of the mold. This eliminates the need for an automatic device for pre-aligning the frames, an automatic device for setting them into a mold, and taking them out.

In FIG. 8 an embodiment of the lead frame arrangement method according to the invention is shown. 6a and 6b are long series, for example, 35 scale lead frame fixed length composites, and as shown in the same figure, they are arranged in two parallel rows facing each other with a cull 8 in between along the mating surface of the mold 7. Place it in

Resin is supplied from cull 8 to each lead frame via main runner 9 and runner 10. FIGS. 4 through 6 show an example of how a lead frame composite is introduced into a mold when the lead frame placement method according to the present invention is employed. The long lead frame composites 6a and 6b are already arranged and transferred in two rows at the interval d in each assembly process such as beret bonding and wire bonding, and are placed on the frame break heater 11 at the interval d as a pre-molding process. The lead frame is placed in a state where it is heated to a predetermined temperature, and the lead frame is pushed in the horizontal direction by a frame pusher (not shown) and moved between the open upper and lower mold molds 7a and 7b, as shown in FIG. 6, for example. The frame holding odor 12 holds it in place. In this state, the upper and lower molds are closed, the lead frame is set inside the mold, and resin molding is performed. A portion of the jig remains in the recess of the mold when the mold is closed, or a portion of the jig is inverted so that at least a portion of the lead frame is directly supported by the mold. After molding, the lead frame moves to the other side while being held by the frame holding odor and escapes from the mold. According to the present invention described in the above embodiments, {1) By increasing the speed of the lead frame, it is possible to mold in two rows in the mold, for example, in the case of 35 layers, 35 × 2 = 70 lead frames can be molded in one 2) The lead frames have already been arranged in two rows in the previous process and can be guided into the mold at the same intervals, making it possible to mold multiple lead frame composite sets unlike the conventional method. An automatic alignment jig is not required, and a device for automatically introducing the material from outside the mold into the mold and a device for automatically ejecting it from the inside of the mold to the outside of the mold can be realized using extremely simple devices.

{3} Two rows of lead frames can be introduced into the mold at the same time and taken out from the mold, which requires less time.'4
Since the river board frame can be moved in parallel and taken out of the mold, various effects are brought about, such as automatic cleaning of the inner surface of the mold. It should be noted that compared to the equipment cost required for loading and unloading of frames in the case of automation using the follow-up method, the cost when the method of the present invention is adopted can be reduced by 1/milk land ratio. The invention is not limited to the above embodiments.

For example, the number of frames in a long continuous frame complex is 39.
It is not limited to 1 heavy weight, but there is no problem in using 4G heavy weight or others.

The present invention can also be applied to a molding device for assembly using a regular length lead frame.

[Brief explanation of the drawing]

Fig. 1 is a plan view showing the form of lead frame (composite) arrangement in a conventional resin mold, and Fig. 2 is a plan view showing the form of an alignment pick used in the conventional frame arrangement method. be. FIG. 3 is a plan view showing a mode in which the lead frame is taken into consideration according to the present invention, and FIGS. 4 is a plan view, FIG. 5 is a front view, and FIG. 6 is a side sectional view. 1...Short lead frame complex, 2.
...Runner, 3...Cal, 4...Type, 5
...Alignment jig, 6...Long lead frame composite, 7...Mold, 8...Runner, 9, 10"""Runner, 1
1"""Frame preheater, 12... Frame holding tool. Measures! Figure 2 Figure 2 Sabaotsu Figure 4 Figure 5 Figure 6

Claims (1)

[Claims] 1. A method for arranging lead frames in a mold, which is characterized by arranging lead frames of a fixed length in two rows when arranging a plurality of lead frames as filling materials in the mold.