JPH0356340Y2 - - Google Patents

Description

[Detailed Description of the Invention] Industrial Application Field The present invention relates to a resin molding device used for manufacturing resin molded semiconductor devices.

2. Description of the Related Art In general, a resin molded semiconductor device has a lead frame in which a number of semiconductor element mounting parts and a required number of leads are formed in series at equal intervals, and each mount part has a semiconductor element mounted thereon. Each of the semiconductor elements and leads are connected with thin metal wires and sent to a resin molding process, where resin molding is performed for each semiconductor element part.
Each lead frame is manufactured separately from the lead frame.

In the resin molding process, cavities are provided at positions corresponding to the respective semiconductor element parts that are formed in large numbers in series on the lead frame, and a runner is provided on one side of each cavity in the direction in which the cavities are arranged, which serves as a common supply path during resin filling. , which has a structure in which each cavity is connected to this runner in a one-to-one correspondence via a gate.
A splittable mold is used and each cavity is pressure filled with resin from one end of the runner through a gate.

As mentioned above, resin molding equipment usually connects each cavity to the runner one by one via a gate, but recently, small resin molded semiconductors called mini flat packages have been developed. As devices are manufactured, each cavity becomes smaller, and connecting each cavity to the runner via a gate as before is inefficient in the use of molds and increases costs. In addition, the width of the lead frame became narrower, which caused problems in that it was difficult to handle the semiconductor device when assembling it.

Therefore, two or more cavities are connected, each cavity is connected with a gate, and one end of the cavity is connected to a runner through a gate, and resin is sequentially filled into the cavity under pressure. Resin molding equipment has come into use.

FIG. 4 is a conventional example, and is an explanatory plan view schematically showing the relationship between the lead frame and the mold in the case of two sets. In the figure, 1 is the lead frame, 2a, 2b are Mini flat packages are installed in two rows in the width direction of the lead frame 1, 3 is a lead formed between the packages 2a, 2b and the lead frame 1, 4a, 4b correspond to the above packages 2a, 2b. The first formed on the mold side
and a second cavity, 5 is a runner, 6a is a first gate, 6b is a second gate, and 7 is an air vent.

In FIG. 4, the resin flows from the runner 5 through each first gate 6a, into the first cavity 4a, and further flows into the second cavity 4b via the second gate 6b, and then flows into each cavity 4a, 4b. The air inside is exhausted from the air vent 7 and resin molding of each package 2a, 2b is performed.

Problems to be solved by the invention In the mini-flat package mentioned above, it is advantageous in terms of cost to use two or multiple lead frames and a multi-piece system, but the resin required for the resin mold of each package is The amount is small and
Since the thickness of the mold resin is thin, the second cavity is better in the case of two series, and the second cavity in the case of multiple series.
There was a problem in that the filling rate of the resin deteriorates as the cavity is further away from the runner after the cavity, and molding defects such as unfilling are more likely to occur.

Means for Solving the Problems The present invention was proposed in view of the above-mentioned problems of conventional resin molding equipment.Multiple cavities are provided in the mold, the cavities are connected with gates, and the resin is sequentially applied. When filling the cavity under pressure,
A resin reservoir is provided at the gate between the cavities.

Effect By providing a resin reservoir at the gate between the cavities, the passage cross-sectional area of the gate between each cavity after the first cavity is increased, and the flow resistance of the resin is reduced, so that the resin flow on the gate is increased. This improves the fluidity of the resin, reduces clogging (hardening) due to loss of resin fluidity in the middle of the gate, and improves the filling rate of resin into each cavity.

Embodiment FIG. 1 is an explanatory plan view schematically showing the relationship between the lead frame and the mold in an embodiment in which the present invention is applied to a two-unit case, and FIG.
FIG. 3 is an enlarged cross-sectional view taken from the line, and is an external perspective view showing an example of a resin molded product according to the present invention.

1 and 2, 1 is a lead frame, and 2a and 2b are 2 in the width direction of the lead frame 1.
3 is a lead formed between the package 2a, 2b and the lead frame 1; 4a, 4b is the mini-flat package installed in series; 3 is the lead formed between the package 2a, 2b and the lead frame 1;
First and second cavities formed in the upper mold 8 and lower mold 9 corresponding to a and 2b, 5 is a runner, 6
a is the first gate, 6b is the second gate, 7 is the air vent, 10 is the first and second cavities 4a, 4b
This is a resin pool formed in the second gate 6b between the two.

The resin reservoir 10 is located in each cavity 4a, 4b.
In order to effectively utilize the dead space between
It is provided in the middle of the gate 6b to extend in the longitudinal direction of the lead frame 1, and its volume and shape are set in consideration of the volume of each cavity 4a, 4b, resin filling pressure, curing speed, etc. in this way,
By forming the resin reservoir 10 using the dead space, the width of the lead frame 1 and the width of the molds 8 and 9 can be kept the same as before.

Each of the resin reservoirs 10 has a length such that adjacent resin reservoirs 10 do not interfere with each other in the longitudinal direction of the lead frame 1.

With the above configuration, when resin is pressurized and filled from one end of the runner 5 during resin molding, the resin flows from the runner 5 through each first gate 6a to each first cavity 4a, and then to each first cavity 4a. 2
It flows into each second cavity 4b from the gate 6b. In this case, since the resin reservoir 10 is provided in the middle of the second gate 6b, the second gate 6b
Since the passage cross-sectional area increases and the flow resistance of the resin decreases, it is possible to reduce the hardening of the resin in the middle of the second gate 6b and improve the filling rate of the resin into the second cavity 4b.

Although the above-mentioned embodiment is a case of two series, it can also be applied to a multiple series of two or more series, in which case resin reservoirs 10 are provided at the gates between each cavity.

Effects of the invention According to the invention, a simple structure in which a resin reservoir is provided at the gate between each cavity enables
It is possible to significantly reduce molding defects such as unfilled resin in each cavity of a multi-unit resin molding device, and improve the moldability of this type of resin molding device.

[Brief explanation of the drawing]

FIG. 1 is an explanatory plan view schematically showing the relationship between the lead frame and the mold in an embodiment in which the present invention is applied to a two-unit case, and FIG.
3 is an external perspective view showing an example of a resin molded product according to the present invention, and FIG. 4 is an explanatory plan view schematically showing the relationship between a conventional lead frame and a mold. It is. 1... Lead frame, 2a, 2b... Package cage, 4a, 4b... Cavity, 5... Runner, 6a, 6b... Gate, 7... Air vent,
8, 9...Mold, 10...Resin reservoir.

Claims (1)

[Scope of Claim for Utility Model Registration] In a resin molding device in which multiple cavities are provided in a mold, the cavities are connected by gates, and resin is sequentially filled into the cavities under pressure, a resin pool is formed in the gate between the cavities. A resin molding device characterized by: