JPH02222569A - Lead frame, semiconductor device and manufacture thereof - Google Patents

Abstract

PURPOSE:To obtain a lead frame formed in a manufacturing process that a low temperature processing can be executed, where lead terminals are surely insulated from each other by isolation and the difference of them in level is surely corrected by a method wherein insulating resin is applied onto, at least, a part of the side of the lead terminals and filled into a part of the gaps between the side faces of the lead terminals. CONSTITUTION:Insulating resin 21 is applied onto, at least, a part of the upsides of two or more lead terminals 12 and filled into a part of the gaps between the side faces of the lead terminals 12. A lead frame provided with the lead part terminals 12 processed as above and a semiconductor element 3 mounted on a die pad 11 of the lead frame are electrically connected together through metal fine wires 5, and the whole body is packaged with sealing resin to constitute a semiconductor device. For instance, the filling of the insulating resin 21 is executed at a normal temperature, a die corresponding to the width of the resin 21 and the shape of the lead terminals 12 is prepared and installed, and the resin is supplied by pressure or through gravity- drop. At this time, the opposite sides of the lead terminals must not be covered with excessive resin, the resin starts to set at a temperature of 200 deg.C or so, and the resin is made to set as keeping the die on a flat face.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to resin-sealed semiconductor devices, particularly lead frames having a stable structure in which lead terminals do not move, and semiconductors using the lead frames. The present invention relates to a device and a method for manufacturing the same.

[Conventional technology]

FIG. 7 is a plan view showing a semiconductor device using a conventional lead frame. In the figure, 11 is a die pad for mounting a semiconductor element on the lead frame, 12 is a lead terminal,
22 is a polyimide tape for fixing the lead terminal 12 so that its position does not move, 3 is a semiconductor element, and 4 is a Guibond material, which connects the semiconductor element 3 and die pad 11.
and are glued together.

A gold wire 5 connects the electrode 31 provided on the semiconductor element 3 and the lead terminal 12. FIG. 8 is a sectional view taken along the line ■--■ in FIG. 7.

Next, the effect will be explained. In recent years, as semiconductor elements 3 have become highly integrated and at the same time the design rules for internal wiring have become finer, the number of electrodes 3 through which signals are exchanged between the semiconductor element 3 and the outside has increased. Electrodes 3 are tightly packed around the area! will be arranged. Furthermore, along with this, the number of lead terminals 12 has increased, and both the width and thickness of the lead terminals have been miniaturized! 2 is used. Although this lead frame has been put into practical use as a result of being manufactured near the processing limit, the mechanical strength of the lead terminals 12 has deteriorated significantly, and deformation occurs even when a slight external force is applied. Easy to connect, lead terminal 12
They may come into contact with each other, or there may be variations in the level difference with respect to the die pad 11. To prevent these problems, we use polyimide (an insulating resin with excellent heat resistance).
Polyimide tape 2 with adhesive attached to KAPTON
2 on the lead terminal 12.

That is, by attaching this polyimide tape 22 to the lead terminal 12, the lead frame can be easily transported, and even when the gold wire 5 is bonded to the lead terminal I2, the lead terminal 12 is fixed and the bond is in a stable state. is possible,
Furthermore, during resin sealing, the lead terminals 12 are prevented from moving due to the inflowing resin and causing a short circuit.

[Problem to be solved by the invention]

A semiconductor device using a conventional lead frame is constructed as described above, and it is necessary to heat the lead frame to about 400°C when applying the polyimide tape 22, which makes it difficult to speed up the tape application process. Moreover, after the semiconductor element 3 is attached, thermal shock to the semiconductor element 3 is unavoidable, reducing the reliability of the semiconductor element 3. Furthermore, since the cost of jigs and tools for applying the polyimide tape 22 is high, there is little freedom in terms of location, shape, size, etc., for applying the tape to various frame patterns.

The biggest drawback is that simply pasting the top surface of the lead terminals 12 does not fill the space between the lead terminals and firmly correct the level difference.

This invention was made to solve the above-mentioned problems, and it not only ensures insulation separation between lead terminals and corrects steps, but also enables low-temperature process (approximately 200°C) to be performed in the manufacturing process. It is an object of the present invention to provide a lead frame, a semiconductor device using the same, and a manufacturing method thereof, in which the cost of a jig and tool for insulating and separating lead terminals is one-tenth that of a conventional one.

[Means to solve the problem]

(2) The invention of the lead frame of this application is such that at least a portion of the lead frame is filled with an insulating resin from one side of a plurality of lead terminals to the side surfaces of the lead terminals, and is hardened and fixed.

■Furthermore, in the semiconductor device invention of this application, the lead frame fixed by the above-mentioned insulating resin and the semiconductor element mounted and fixed on the die pad of the lead frame are electrically connected by thin metal wires. The entire device was packaged with sealing resin.

■The method for manufacturing a semiconductor device of this application is to fix a plurality of lead terminals while correcting their steps using magnetic force or a fixing means such as a holding jig, and in this state, from one top surface of the lead terminal to the side surface of the lead terminal. The insulating resin is filled and cured over a period of time.

[Effect]

In the invention of the lead frame and the semiconductor device using the lead frame of this application, by filling with insulating resin,
Insulation separation between lead frame terminals and mutual fixation are securely performed. Furthermore, the level difference between the lead terminals can be reliably corrected. Furthermore, there is no need to worry about breakage of the thin metal wire after wire bonding.

Furthermore, the insulating resin is inexpensive, has excellent processability, and is easy to handle because it hardens in a low-temperature process.

On the other hand, the method for manufacturing a semiconductor device of the present application involves fixing lead terminals with uneven steps so that they are aligned on a flat surface, and then filling and hardening the insulating resin, which corrects the steps by a simple means. be able to.

〔Example〕

FIG. 1 is a plan view showing a semiconductor device using a lead frame according to an embodiment of the present invention, and FIG. 2 is a sectional view taken along the line ■-■ in FIG. Guibond material, 5 is thin metal wire (gold wire),! l is die pad,
12 is a lead terminal, and 21 is an insulating resin, which is filled from the upper surface of the lead terminal 12 to between the lead terminals to play the role of insulation separation and to prevent variations between the lead terminals.

Next, the manufacturing process will be explained.

(1) First, a method of filling the insulating resin 21 will be explained.

Filling is carried out at room temperature. A mold corresponding to the width of the resin and the shape of the lead terminal is prepared and installed, and the resin is supplied under pressure or by falling under its own weight. At this time, depending on the amount of insulating resin supplied,
Do not completely cover the opposite side of the lead terminal 12 (back side in the figure).

Note that the mold used for resin filling can be manufactured at one-tenth the cost of conventional pasting jigs and tools.

(2) Next, resin curing methods for each type of lead frame (classified by patterning manufacturing method) will be explained.

(a) Figure 3 is an enlarged plan view showing the state of resin adhesion on a frame manufactured by the etching method.
The figure is a sectional view thereof. The cross-sectional shape of the lead terminal 12a manufactured by the etching method has a concave side surface, and unevenness in steps is unlikely to occur. Therefore, the insulating resin 21 used is not influenced by the elastic modulus, and is made of silicone resin. Or epoxy resin etc. are suitable. Then, the resin is cured at a temperature of 200° C. while being placed on a flat surface.

(b) FIG. 5 is a cross-sectional view of a lead terminal of a lead frame manufactured by the punching method, and this lead terminal 12b
Although the cross section of the lead terminal 12b has a side surface cut straight, stress from cutting remains on the lead terminal 12b, and steps and variations are likely to occur.

Therefore, in order to correct the above-mentioned level difference, insulating resin with low elasticity,
For example, an epoxy resin with a low silica content is used. The temperature at the time of curing is about 200° C., and as shown in FIG. 6, by curing while fixed with a magnetic coil 6, unevenness in level difference can be corrected. Further, in the above description, the lead terminal 12b is fixed by the magnetic coil 6, but the same effect can be obtained by using a tool that presses the lead terminal 12b from above and below.

■Furthermore, when wire-bonding the lead terminals 12 of the lead frame and the semiconductor element 3 that have been bonded to each other using the thin metal wires 5, the step of the lead terminals 12 is corrected, so that no external force is applied from the lead terminals 12 to the gold wires 5. There is no problem of deformation of the gold wire 5 due to working.

■The elastic modulus of the insulating resin 12 is! , 0-20
．． OX 10”dyn/a/ would be effective for correcting the level difference.

〔Effect of the invention〕

In the lead frame invention of this application, since the insulating resin is filled between the lead terminals, the insulation separation and mutual fixation of the lead terminals are firmly performed, and the level difference between the lead terminals is also reliably corrected. . Further, in a semiconductor device using this lead frame, since the level difference between the lead terminals is reliably corrected, a reliable device without breakage of thin metal wires etc. can be obtained.

In addition, according to the manufacturing method of this application, since an insulating resin is used, the manufacturing process can be sped up by a low-temperature process, and it is inexpensive for various lead frame patterns. etc. can be set freely, and has the effect of providing a highly reliable semiconductor device in an inexpensive and simple manner.

[Brief explanation of the drawing]

FIG. 1 is a plan view of a semiconductor device using a lead frame according to an embodiment of the present invention, FIG. 2 is a sectional view taken along the line ■-■ in FIG. 1, and FIG. 3 is a lead terminal manufactured by an etching method. FIG. 4 is a side view of FIG. 3, and FIG. 5 is an enlarged sectional view of FIG.
The figure is a cross-sectional view of a lead terminal manufactured by the punching method, FIG. 6 is a cross-sectional view showing a fixed state of the lead terminal, and FIG. 7 is a plan view of a semiconductor device using a conventional lead frame.
FIG. 8 is a sectional view taken along the line ■--■ in FIG. 7. In the figure, 3 is a semiconductor element, 4 is a Guibond material, 5 is a thin metal wire, 11 is a die pad, 12, 12a, 12b are lead terminals, 21 is an insulating resin, 31 is an electrode, and 6 is a magnetic coil. Note that the same reference numerals in the figures indicate the same or equivalent parts.

Claims (3)

[Claims] (1) A lead frame characterized in that at least a portion of a plurality of lead terminals is filled with an insulating resin from an upper surface to a side surface of the lead terminals. (2) A semiconductor in which the lead frame according to claim 1 and a semiconductor element placed and fixed on a die pad of this lead frame are electrically connected by thin metal wires, and the whole is packaged with a sealing resin. Device. (3) Fix the plurality of lead terminals using magnetic force or fixing means such as a holding jig while correcting the level difference, and in this state, fill insulating resin from one top surface of the lead terminals to the side surface of the lead terminals. A method for manufacturing a semiconductor device, characterized in that it is cured.