JPH03280562A - Lead frame and semiconductor device resin sealing method - Google Patents

Abstract

PURPOSE:To prevent the void failures on a package surface without damaging a package or a semiconductor chip, by equipping the outer frame of a lead frame with a hole for passing resin sealing material which hole has a sectional area smaller than the horizontal sectional area of a void discharging cavity of a metal mold for resin-sealing semiconductor mounting. CONSTITUTION:The outer frame 1 of a lead frame is equipped with a resin passing hole 8 whose area is smaller than the horizontal sectional area of a second cavity (void discharging cavity) 24 of a metal mold 20 for resin-sealing a semiconductor chip. Resin 11A containing voids on and under the lead frame is trapped, through the resin passing hole 8 of the lead frame, in the second cavity 24 linked to a second gate 23 for discharging voids generated in a first cavity 22. Thereby, when a completed product is cut off from the second gate 23, and the lead is subjected to bending molding process, the resin 11A molded by the second cavity (void discharging cavity) 24 is vertically fixed penetrating the resin passing hole 8, and the exfoliation from the lead frame can be prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a lead frame and a method for resin-sealing a semiconductor device, and particularly relates to a technique for preventing the formation of a board on the surface of a package.

[Prior art]

Conventionally, boarding occurs due to an imbalance in the injection amount of resin on the semiconductor chip inside the package and resin under the tab. As a measure to prevent this, for example, as described in Japanese Patent Application Laid-Open No. 60-126841, there is a method for resin-sealing semiconductor devices in which a cavity is connected to a runner connected to a pot via a gate. The mold includes a first gate for cutting the finished product from the runner, a first cavity connected to the first gate, a second gate for discharging the board produced in the first cavity, and a second gate for discharging the board produced in the first cavity. A mold for resin-sealing a semiconductor device has been proposed, which is connected to a second gate and serves as a second cavity for trapping the board.

[Problem to be solved by the invention]

However, as a result of studying the above-mentioned conventional techniques, the inventor of the present invention discovered the following problem.

When the finished product is cut from the second gate and leads are molded, the resin molded in the second cavity peels off from the cut lead frame, and the separated small pieces of resin are placed between the surface of the package and the fixing device. Penetration due to the pressure of the fixation device.

This may cause damage to the package or semiconductor chip.

An object of the present invention is to provide a technique that can prevent board defects on the surface of a package without damaging the package or the semiconductor chip.

The above and other objects and novel features of the present invention will become apparent from the description of this specification and the accompanying drawings.

(Means for Solving the Problems) A brief overview of one typical invention disclosed in this application is as follows.

This lead frame is provided with a resin sealing material passage hole having a horizontal cross-sectional area smaller than the horizontal cross-sectional area of a board discharge cavity of a mold for resin-sealing a semiconductor device in the outer frame of the lead frame.

This lead frame, a first gate for cutting the finished product from the runner, a first cavity connected to the first gate, a second gate for discharging the board produced in the first cavity, and a second gate for discharging the board produced in the first cavity. A semiconductor device using a semiconductor device resin molding mold comprising a second cavity connected to a second gate and trapping the board above and below the lead frame through a resin molding material passing hole in the lead frame. This is a resin sealing method.

[Effect]

According to the above-mentioned means, the outer frame of the lead frame is provided with a hole through which the resin encapsulant (hereinafter referred to as resin) passes, and whose horizontal cross-sectional area is smaller than the horizontal cross-sectional area of the board ejection cavity of the semiconductor device resin encapsulant mold. Using a lead frame provided on the outer frame of the lead frame, the resin passage hole of the lead frame is passed through the second cavity connected to the second gate for discharging the board generated in the first cavity. cutting the finished product from the second gate by trapping resin containing the board above and below;
When molding leads, the resin molded in the second cavity (board ejection cavity) does not separate from the top and bottom of the lead frame that is cut through the resin passage hole. Since there is no intrusion between the surface of the device and the fixing device, the package or the semiconductor chip will not be damaged by the pressure of the fixing device.

This makes it possible to prevent board defects on the surface of the package without damaging the package or the semiconductor chip.

Hereinafter, one embodiment of the present invention will be specifically described using the drawings.

Note that throughout the description of the embodiments, parts having the same functions are given the same reference numerals, and repeated explanations thereof will be omitted.

[Example ■]

1 is a plan view showing a schematic structure of a lead frame according to Example 1 of the present invention, and FIG. 2 is a plan view of a semiconductor device assembled using the Nyororito frame of Example 1 shown in FIG. Plan view - FIG. 3 is a sectional view for explaining one method of resin sealing the semiconductor device according to the first embodiment of the present invention.

This example! As shown in Figure 1, the lead frame of
O, 15mm 71. (It is made by punching or etching a metal plate.Although the shape has different widths in some parts, the semiconductor chip is placed in the center of the frame part 1 which forms a four-shaped frame as a whole.) A quadrilateral tab 3 is provided for attaching the frame 1. The tab 3 is supported by narrow tab suspension leats 4 whose four outer ends are respectively connected to the inner corners of the frame 1.

Also, multiple nodes 5 from the 4 directions toward this tab 3.
extends, and its tip (inner end) faces near the peripheral edge of the tab 3.

Further, the rear ends of the leads 5 extending in four directions are each connected to a frame portion 1.
is connected inside. Furthermore, a dam piece 6 extending between the leads 5 and between the leads 5 and the frame portion 1 is arranged to surround the tab 3 in order to prevent melted resin from flowing out during resin molding. Further, the frame portion 1 is provided with a guide hole 7.

In addition, at a position facing the resin injection port 10 of the frame portion 1,
A quadrilateral passage hole 8 according to the invention is provided. This quadrilateral passage hole 8 has an area (horizontal cross-sectional area) smaller than the horizontal cross-sectional area of a board ejection cavity of a mold for resin-sealing a semiconductor device, which will be described later. Furthermore, a thermal stress reduction hole 9 is provided at a predetermined position of the frame portion 1 to reduce thermal stress during resin molding.

When assembling a semiconductor device using such a lead frame, as shown in FIG. After that, as shown in FIG.
The resin 11 is injected into the first cavity 22 of the dam piece 6, and the inside of the dam piece 6 is molded with the resin 11.

As shown in FIG. 3, the mold 20 for resin-sealing a semiconductor device is provided with a first cavity 22 connected via a first gate 21 to a runner connected to a pot.

A second gate 23 is provided for discharging the board produced in the first cavity 22, and is connected to the second gate 23 to trap the board above and below the lead frame through the resin passing hole 8 of the lead frame. A second cavity 24 is provided for this purpose. The height of this second cavity 24 is configured to be lower than the height of the first cavity 22.

According to the semiconductor device resin encapsulation method of Example I, the semiconductor chip resin encapsulation mold 20 is attached to the outer frame 1 of the lead frame.
A second gate 23 for discharging the board produced in the first cavity 22 is formed using a lead frame provided with a resin passing hole 8 having an area smaller than the horizontal cross-sectional area of the second cavity (board discharge cavity) 24. The finished product is cut from the second gate 23 by trapping the resin IIA including the board on the top and bottom of the lead frame through the resin passing hole 8 of the lead frame into the connected second cavity 24, and the lead When performing the bending process, the resin IIA formed in the second cavity (board ejection cavity) 24 passes through the resin passage hole 8 and is fixed vertically, and is peeled off from the lead frame to be cut. Therefore, small pieces of resin do not enter between the surface of the package 32 and the fixing device, and damage to the package 32 or the semiconductor chip 2 due to the pressure of the fixing device can be prevented.

As a result, when injecting the resin 11 into the semiconductor device resin sealing mold 20, even if the injection amount of the resin 11 on the semiconductor chip 2 inside the package 32 and the under-tab resin 11 is out of balance, the package 32 or the semiconductor It is possible to prevent board defects on the surface of the package 32 without damaging the chip 2.

[Example ■]

FIG. 4 shows the S OJ (Small) of Example H of the present invention.
FIG. 2 is a plan view showing a schematic configuration of a lead frame of an out-line (J-bend) type resin-sealed package.

As shown in FIG. 4, the semiconductor chip 2 of this embodiment (■) is
S OJ (Small 0ut-1ine J-b
end) type resin-sealed package 32. The semiconductor chip 2 has, for example, 16 [Mbit]
Large capacity DRAM (Dy
namic Random AccessMemory
), 1.6.48 [mm] x 8.54 [
It is composed of a flat rectangular shape of mml. This semiconductor chip 2 is sealed in a 400 mil resin-paired F-type package 32.

The lead frame 33 includes 20 signal inner leads 33A and two common inner leads (busbars) 33A.
,, It is composed of 24 outer leads 33B and 2 support leads (hanging leads) 33C.

Further, a resin passage hole 33E is provided in the frame portion at a position facing the resin injection port 33D.

This lead frame 33 has, for example, F e −N i (
For example, an alloy with a Ni content of 42 or 50%.

It is made of Cu or the like.

This type of resin-sealed package 32 is a semiconductor chip 2.
A signal inner lead 33A and a common inner lead (bus bar) 33A are arranged on the main surface of the
Adopts a lead-on-chip structure.

The resin-sealed package 32 employs a LOG structure.

Since the signal inner leads 33A can be routed freely without being restricted by the shape of the semiconductor chip 2, it is possible to seal a large semiconductor chip 2 by an amount corresponding to the route. In other words, in the resin-sealed package 32 that adopts the LOG structure, even if the size of the semiconductor chip 2 increases due to increased capacity, the sealing size (package size) can be kept small, making it possible to increase the packaging density. can.

When assembling a semiconductor device using such a lead frame 33, the signal inner leads 33A,
The common inner lead (bus bar) 33A and the support lead (hanging lead) 33C are adhesively fixed, and the electrodes of the semiconductor chip 2 and each of the inner leads 33A, 33A are electrically connected with wires, and then the As shown in FIG.
The resin 11 is injected into the first cavity 22 of the semiconductor device resin sealing mold 20, and the resin 11 is molded inside the first cavity 22 of the dam piece 6.

By doing this, when cutting the finished product from the second gate 23 and bending the leads as in Example I, the resin molded in the second cavity (board ejection cavity) 24 can be removed. IIA is resin passage hole 3
3E and is fixed on the top and bottom, and will not peel off from the lead frame 33 to be cut, so small pieces of resin will not enter between the surface of the package and the fixing device, and the pressure of the fixing device will prevent small pieces of resin from entering between the package surface and the fixing device. , the package or the semiconductor chip 31 can be prevented from being damaged.

As a result, when the resin 11 is injected into the semiconductor device resin sealing mold 20, the semiconductor chip 2 inside the package is
Even if the injection amount of the upper resin 11 and the lower resin 11 of the semiconductor chip 2 is out of balance, the package or the semiconductor chip will not be damaged, and board defects on the package surface can be prevented.

The present invention has been specifically explained above based on examples, but
It goes without saying that the present invention is not limited to the embodiments described above, and can be modified in various ways without departing from the spirit thereof.

〔Effect of the invention〕

A brief explanation of the effects obtained by typical inventions disclosed in this application is as follows.

When injecting resin into a mold for resin-sealing a semiconductor chip, even if there is an imbalance between the amount of resin 11 on the semiconductor chip inside the package and the resin under the tab or semiconductor chip, the package or semiconductor chip may be damaged. without any
Board defects on the package surface can be prevented.

[Brief explanation of drawings]

FIG. 1 is a plan view showing a schematic configuration of a lead frame according to Example 1 of the present invention. FIG. 2 is a plan view of a semiconductor device assembled using the lead frame according to Example 1 shown in FIG. 1, and FIG. 3 illustrates a method for resin-sealing a semiconductor device according to Example I of the present invention. FIG. 4 is a plan view showing a schematic structure of a lead frame of an SOJ type resin-sealed package according to Example H of the present invention. In the figure, 1... frame portion, 2... semiconductor chip, 3...
Tab, 4...Tab hanging lead, 5...Lead, 6...
Dam piece, 7...Guide hole, 8.331! :・Resin passage hole, 9...Thermal stress reduction hole, 10.33D...Resin 1L included], 11...Resin, IIA...Resin including board, 2o...Semiconductor device I+'? Resin-sealed river mold 21, 1st gate, 22 mountain 1st gear, bitty, 23
...Second gate, 24..Second cavity, 31..Insulating film, 32..Package, 33.Lead frame, 33A..Inner lead for signal, 33A.・・Common inner lead (busbar), 3313・・7
S7 tar lead, 33C...Support lead (hanging lead).

Claims (1)

[Claims] 1. A resin encapsulant passage hole having a horizontal cross-sectional area smaller than the horizontal cross-sectional area of a board ejection cavity of a semiconductor device resin encapsulant mold is provided in the outer frame of the lead frame. Characteristic lead frame. 2. The lead frame according to claim 1, a first gate for cutting the finished product from the runner, a first cavity connected to the first gate, and a first cavity for discharging the board produced in the first cavity. 2 gates, and a second cavity connected to the second gate for trapping the board above and below the lead frame through a resin sealing material passing hole in the lead frame. A semiconductor device resin encapsulation method characterized by using the following.