JPH10178146A - Lead frame and semiconductor device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce slippages of the inner leads of a lead frame due to shrinkage in tapes and to enhance the use efficiency of the tapes by a method wherein an overlapping margin is provided on the upper and lower surfaces of the lead frame to paste the tapes to the upper and lower surfaces of the lead frame. SOLUTION: Two tapes 11 and 12 cut rectangularly are stretched on the upper surfaces of the inner lead and suspension pin parts 7 and 5 of a lead frame 2 in a direction Y and two tapes 13 and 14 cut rectangularly are pasted to the lower surfaces of the inner lad and suspensiton pin parts 7 and 5 of the lead frame 2 in a direction X. Moreover, the tapes 11 and 12 and the tapes 13 and 14 are stretched in such a way that the end parts of the tapes 11 and 12 are superposed on the end parts of the tapes 13 and 14 via the lead frame 2. Slippages, which are generated on the inner leads by a shrinkage in the tapes pasted to the upper surface of the lead frame, and slippages, which are generated on the inner leads by a shrinkage in the tapes pasted to the lower surface of the lead frame, negate to each other and the slippages of the inner leads can be reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lead frame and a semiconductor device, and more particularly to a lead frame to which a tape is attached and a semiconductor device.

[0002]

2. Description of the Related Art In a QFP (Quad Flat Package), there is a type in which a lead frame is taped in order to prevent an inner lead and a bed from rising and falling. FIG.
Shows an example of the taping shape of the tape attached to the lead frame. This tape 1 has a square shape,
It is attached only to the upper surface of the lead frame 2. Less than,
The upper surface refers to the chip mounting surface, and the lower surface refers to the surface opposite to the chip mounting surface.

[0003]

In the conventional example shown in FIG. 5, a wide tape is generally punched out to form a square-shaped tape, and the tape 1 is attached to the lead frame 2. However, in this method, the tape inside the square is punched out and discarded, so that the tape utilization efficiency is very low.

Therefore, in order to improve the utilization efficiency of the tape, a strip-shaped tape may be used instead of a wide tape. 6 and 7 show a lead frame to which a strip-shaped tape is attached.

In the conventional example shown in FIG. 6, a strip-shaped tape 3 having the same length as one side of the square-shaped tape 1 shown in FIG.
And two rectangular tapes 4 slightly shorter than the tape are used to perform taping in a rectangular or square shape. The tapes 3 and 4 are arranged so as not to overlap each other.

In the conventional example shown in FIG. 7, taping is performed using four strip-shaped tapes 3 having the same length as one side of the square-shaped tape 1 shown in FIG. Tape 3
Are arranged so as to overlap each other.

In the conventional example shown in FIGS. 6 and 7, since a strip-shaped tape is used, the use efficiency of the tape is improved as compared with the conventional example shown in FIG. However, in the example shown in FIG. 6, the length of the tape is different between the X direction and the Y direction as described above. Normally, the tape is stuck by heating the lead frame. When the temperature of the tape is returned to room temperature after the tape is stuck, the tape shrinks. If the length of the tape is different between the X direction and the Y direction, the tape shrinks and the inner lead shifts.

In the example shown in FIG. 7, there is a portion where the tape is further stretched on the tape as described above. Since the thickness of the tape is, for example, about 70 μm, a portion between the ends of the tape whose ends are on the tape is raised, and there is a possibility that a part of the tape does not adhere to the inner leads. For this reason, the tape attachment becomes uneven.

SUMMARY OF THE INVENTION The present invention has been made in consideration of the above problems, and has as its object to increase the efficiency of tape use and reduce costs while suppressing the occurrence of deviation of inner leads and uneven tape attachment.

[0010]

In order to solve the above-mentioned problems, a lead frame according to the present invention comprises a plurality of inner leads, a plurality of first tapes stretched on an upper surface of the inner leads, and a lower surface of the inner leads. A plurality of second tapes that are stretched, and both ends of the first tape are
The first tape is stretched on the upper surface of the inner lead on which the tape is stretched. Between the ends of the first tape, the tape is stretched on the upper surface of the inner lead having no tape on the lower surface, and both ends of the second tape are stretched. Is stretched on the lower surface of the inner lead having an end portion of the first tape stretched on the upper surface, and is stretched on the upper surface of the inner lead having no tape stretched on the upper surface, between the end portions of the second tape. .

According to another aspect of the present invention, there is provided a semiconductor device comprising: a bed; a plurality of inner leads provided around the bed; and a plurality of first tapes attached to the upper surface of the inner lead. A plurality of second tapes stretched on the lower surface of the inner lead, and both end portions of the first tape are stretched on the upper surface of the inner lead having an end portion of the second tape stretched on the lower surface, Between the ends of the first tape, the inner lead is stretched on the upper surface of the inner lead having no tape stretched on the lower surface, and both ends of the second tape are stretched on the upper surface with the end of the first tape stretched on the upper surface. Between the end of the second tape and the lead frame stretched on the upper surface of the inner lead without the tape stretched on the upper surface, and placed on a bed of the lead frame and sealed with resin. Semiconductor chip That.

[0012]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows a first embodiment of the present invention. FIG. 1A shows the upper surface of a lead frame to which a tape has been attached. FIG. 1B shows the lower surface of the lead frame shown in FIG. 1A. Hereinafter, the same components are denoted by the same reference numerals, and description thereof will be omitted.

As shown in FIG. 1, the upper surface of the inner lead 7 and the suspension pin 5 of the lead frame 2 is
Tapes 11 and 12 cut into strips of a book are stretched. The tapes 11 and 12 are provided to face each other with the bed 6 therebetween. Further, tapes 13 and 14 cut into two strips in the X direction are attached to the lower surfaces of the inner lead portion 7 and the suspension pin portion 5 of the lead frame. The tapes 13 and 14 are opposed to each other across the bed. A rectangle or square is formed by these four tapes 11 to 14.

The end portions of the tapes 11 and 12 and the tape 1
3 and 14 are stretched so as to overlap with the ends of the lead frame 2. Usually, the ends of the tapes 11 to 14 are attached to the hanging pin portions 5.

In the present embodiment, the shift generated in the inner lead due to the contraction of the tape stretched on the upper surface of the lead frame and the shift generated in the inner lead due to the shrinkage of the tape stretched on the lower surface of the lead frame cancel each other, and the inner lead is reduced. Deviation can be reduced. Further, the adhesive state of the tape does not become uneven.

Further, in the present embodiment, since a strip-shaped tape is used, the use efficiency of the tape can be increased as compared with the case where a rectangular or square shape is punched out. Hereinafter, a process of forming a semiconductor device by resin-sealing a semiconductor chip on a lead frame to which the tape is attached will be described.

First, the bet portion 6 of the lead frame 2
The semiconductor chip 9 is mounted on. Next, the bonding pads on the semiconductor chip and the inner leads 7 of the lead frame 2 are electrically connected using bonding wires (not shown). At this time, the lead frame is heated via the heater 8 installed below the lead frame. FIG.
2A and 2B are cross-sectional views of the lead frame 2 installed in the conventional heater 8 in the Y and X directions, respectively. As shown in FIG.
The lead frame 2 floats where the wire 4 is not stretched. Therefore, the recesses 1 are formed in the heater 8 corresponding to the tapes 13 and 14 attached to the lower surface of the lead frame 2.
0 is provided. FIGS. 2C and 2D show the lead frame 2 installed in the heater 8 in the Y direction and the X direction, respectively.
FIG. As a result, it is possible to prevent the lead frame 2 from floating.

Next, the semiconductor chip and the bonding wires are sealed with resin. Conventionally, since the tape is applied only to the upper surface of the lead frame, the resistance of the tape to the flow of the resin is asymmetric between the upper surface and the lower surface. However, in this embodiment, the tape is attached to the upper and lower surfaces of the lead frame. In addition, at the time of resin sealing, the gate is generally provided toward the suspension pin, and the resin is injected toward the suspension pin. In this embodiment, the arrangement of the tape with respect to the extending direction of the suspending pin 5 is symmetrical between the upper surface and the lower surface of the lead frame. Therefore, in this embodiment, the resistance of the tape is equal on the upper surface and the lower surface.

FIG. 3 shows the semiconductor device thus formed. 21 indicates a resin package, and 22 indicates a pin. Tapes 11 to 14 are attached to the lead frame 2. In this semiconductor device, the occurrence of the shift of the inner lead is suppressed, and the ups and downs of the inner lead and the bed are reduced.

FIG. 4 shows a second embodiment of the present invention. FIG. 4A shows the upper surface of a lead frame to which a tape has been attached. FIG. 4B shows the lower surface of the lead frame shown in FIG.

On the upper surface of the lead frame of this embodiment, in addition to the tapes 11 and 12 shown in FIG.
Tapes 15 and 16 shorter than the intervals of 1 and 12 are further attached. Also, on the lower surface of the lead frame, FIG.
In addition to the tapes 13 and 14 shown in FIG.
Tapes 17 and 18 shorter than the intervals between 3 and 14 are further attached.

Tapes 15 and 16 are tape 1 respectively.
Stretched on the opposite sides of the tapes 3 and 14 so as not to overlap the tapes 11 and 12. Similarly, the tapes 17 and 18 are attached to the opposite sides of the tapes 11 and 12, respectively, so as not to overlap the tapes 13 and 14.

Also, both ends of the tapes 11 to 14 are usually
It is stretched on the hanging pin 5. In this embodiment, as in the embodiment shown in FIG. 1, the deviation of the inner lead can be reduced. Further, the adhesive state of the tape does not become uneven, and the use efficiency of the tape is improved.

Further, in this embodiment, since the lead frame 2 does not float during bonding as shown in FIG. 2B, it is not necessary to process the heater 8 to form the recess 10. Cost can be reduced. In the resin-sealed semiconductor device using the lead frame shown in FIG.
An effect similar to that of the semiconductor device shown in FIG. 3 can be obtained.

[0025]

As described above, according to the present invention,
Since the tape is attached while providing an overlap margin on the upper surface and the lower surface of the lead frame, the shift of the inner lead due to the contraction of the tape can be reduced. Further, according to the present invention, since a strip-shaped tape is used, it is possible to increase the use efficiency of the tape.

[Brief description of the drawings]

FIG. 1 is a diagram showing a first embodiment of the present invention.

FIG. 2 is a sectional view showing a lead frame and a heater when bonding is performed.

FIG. 3 is a diagram showing a semiconductor device using the embodiment shown in FIG. 1;

FIG. 4 is a diagram showing a second embodiment of the present invention.

FIG. 5 is a diagram showing a first conventional example.

FIG. 6 is a diagram showing a second conventional example.

FIG. 7 is a diagram showing a third conventional example.

[Explanation of symbols]

 2: Lead frame, 5: Hanging pin, 6: Bed, 7: Inner lead, 8: Heater, 9: Semiconductor chip, 11 to 18: Tape, 21: Resin, 22: Pin.

Claims (8)

[Claims] A plurality of first tapes stretched on an upper surface of the inner lead; a plurality of second tapes stretched on a lower surface of the inner lead; Both ends of the first tape are attached to the upper surface of the inner lead having the lower surface to which the end of the second tape is attached, and between the ends of the first tape, the inner tape having no lower surface attached to the inner tape. The both ends of the second tape are stretched on the lower surface of the inner lead having the upper surface on which the end of the first tape is stretched, and between the ends of the second tape, A lead frame attached to the upper surface of an inner lead having no tape attached to the upper surface. 2. The lead frame according to claim 1, wherein a rectangle is formed by said first tape and said second tape. 3. The lead frame according to claim 1, wherein the inner lead having an end portion of the tape stretched on an upper surface and a lower surface is a hanging pin. 4. An inner lead whose lower surface is stretched between the ends of the second tape is stretched on the upper surface of the inner lead, and both ends are formed of the first tape.
A third tape not overlapped with the end of the first tape, and a lower surface of an inner lead having an upper surface stretched between the ends of the first tape, and both ends of the third tape are the ends of the second tape. The lead frame according to claim 1, further comprising: a fourth tape not overlapped with the portion. 5. A bed, a plurality of inner leads provided around the bed, a plurality of first tapes stretched on an upper surface of the inner lead, and a plurality of first tapes stretched on a lower surface of the inner lead. A second tape, wherein both end portions of the first tape are stretched on an upper surface of an inner lead having a lower surface to which an end portion of the second tape is stretched, and between both end portions of the first tape. Is stretched on the upper surface of the inner lead with no tape stretched on the lower surface, and both end portions of the second tape are stretched on the lower surface of the inner lead with the end portion of the first tape stretched on the upper surface, A lead frame attached to the upper surface of the inner lead having no tape attached to the upper surface, between the ends of the second tape; and a resin chip mounted on a bed of the lead frame and sealed with resin. Having A semiconductor device characterized by the above-mentioned. 6. The semiconductor device according to claim 5, wherein a rectangle is formed by said first tape and said second tape. 7. The semiconductor device according to claim 5, wherein the inner lead having an end portion of the tape stretched on an upper surface and a lower surface is a suspension pin. 8. The lead frame has a second surface on a lower surface thereof.
The third tape is stretched on the upper surface of the inner lead having the end portion of the first tape stretched, and both ends are not stretched and overlapped with the end portion of the first tape. 6. A fourth tape which is stretched on a lower surface of the inner lead having a stretched portion and has both ends not overlapped with the end of the second tape. Semiconductor device.