JPH07118494B2 - Tape carrier for mounting integrated circuits - Google Patents

Description

TECHNICAL FIELD The present invention relates to a structure of a sprocket hole of a tape carrier.

[Conventional technology]

Conventionally, bumps and ILB (In
ner Lead Bonding) The tape carrier for connecting
A 35 μm-thick copper foil was pasted on an insulating film made of Kapton with an adhesive, and then a lead frame was formed by a photoetching method. Here as a tape,
Since the three-layer structure consisting of insulating film-adhesive-copper foil was used, there is a drawback that the insulating film is thermally deformed by the heat from the bonding tool at the time of ILB. Was not suitable as a mounting tape carrier. It is a tape carrier composed of a single layer of copper foil that solves this drawback and is used in place of it. That is, the structure was as shown in FIG. As for the thickness of the tape carrier composed of one layer of copper foil, a tape having a thickness of 70 μm has been generally used in terms of heat dissipation characteristics and mechanical strength.

However, in a structure that requires an extremely large number of pins and a narrow lead pitch, it is difficult to form the structure by etching from one side due to the restriction of the side etching amount. For this reason, the sprocket hole and the device hole have been a method of joining by etching from both the front and back sides of the tape.

[Problems to be Solved by the Invention]

In the conventional tape carrier consisting of one layer of copper foil which requires a very large number of pins and a narrow lead pitch, as shown in FIG.
As shown in (c), since the front surface and the back surface of the tape are separately exposed, for example, there is a drawback that a positional deviation occurs between the front sprocket hole 1i and the back sprocket hole 1j. .

Therefore, tape transportation during tape carrier production, alignment of LSI chip and tape carrier during ILB, and OLB
(Outer Lead Bonding) For cutting and molding the lead frame, the sprocket hole that is used when cutting and molding the lead frame is not fitted well and the sprocket hole is damaged, resulting in the production and assembly of the tape carrier. However, there was a problem that the yield of the product did not increase and the cost increased.

The present invention provides a tape carrier for mounting an integrated circuit, which prevents the positional deviation between the front and back surfaces of the sprocket hole as described above.

[Means for Solving the Problems]

In the tape carrier of the present invention, at least the sprocket hole has a first opening portion having a first size from one surface of the carrier tape and having a depth equal to or more than half the plate thickness of the tape metal layer, From the other surface of the tape at the same position as the first opening, a depth having a second size larger than the first size and having a metal layer thickness of half or more and less than the plate thickness is formed. And a second opening portion having a depth, and the formation area of the first opening portion is completely located within the formation area of the second opening portion.

That is, the tape carrier of the present invention has sprocket holes having different sizes on the front surface and the back surface of the tape. Therefore, the effective diameter of the sprocket hole is increased, the insertion pin inserted into the hole is well fitted, and the sprocket hole is not damaged.

〔Example〕

Next, the present invention will be described with reference to the drawings. 1 (a) is a plan view showing a first embodiment of the present invention, FIG. 1 (b) is a sectional view taken along the line AA of FIG. 1 (a), and FIG. 1 (c) is It is the BB sectional view taken on the line of FIG. 1 (a).

The method of forming the tape carrier of the present invention will be described below in order of 70 μm.
After applying photoresist to both sides of a thick copper foil single layer tape, exposing and developing the sprocket hole 1b and the device hole 2 on one side (rear side), tape with a well-known etching solution, such as cupric chloride About half of the thickness is etched (so-called half etching). Next, the etched portion is masked, and the sprocket hole 1a, the device hole 2, and the lead frame 3 are formed on the opposite surface (front surface) of the tape by the photoetching method as described above. In this way the front sprocket hole 1a
And the sprocket hole 1b on the back side can be penetrated. The sprocket hole 1b formed on the back surface may be formed with a size including the maximum positional deviation amount (about ± 150 μm) of the photomask during exposure. Finally, if the photoresist is peeled off and well-known gold plating or tin plating is performed, the tape carrier according to the present invention can be realized.

In the present embodiment, the sprocket hole 1b formed on the back surface is formed larger than the sprocket hole 1a formed on the front surface, but the sprocket hole 1b can be formed with the opposite size.

FIGS. 2A to 2C are plan views of the second embodiment of the present invention.

In this embodiment, the sprocket hole shape is a shape other than a quadrangle. 2 (a) is a circular embodiment, and FIG. 2 (b) is an elongated hole-shaped embodiment.
FIG. 6 (c) shows another embodiment having a hexagonal shape. By adopting the circular shape shown in FIG. 2 (a), the fitting with the insertion pin can be improved more than the first embodiment. That is, by tapering the shape of the insertion pin into a conical shape, it is possible to absorb the finished dimensional error of the sprocket hole and realize stable fitting.

2 (a) to 2 (c), each row is shown as having the same shape, but one row may be combined with another shape.

〔The invention's effect〕

As described above, the present invention improves fitting with the insertion pin by having sprocket holes having different sizes on the front surface and the back surface of the tape, and it is possible to prevent damage to the sprocket holes, and Since the manufacturing yield can be improved, the cost can be reduced. Further, since the alignment accuracy during ILB and OLB can be improved, there is an effect that the assembly yield can be measured.

[Brief description of drawings]

FIG. 1 (a) is a plan view showing the entire tape carrier of the first embodiment according to the present invention, and FIG. 1 (b) is a sectional view taken along the line AA of FIG. 1 (a). Figure (c) is Figure 1 (a).
2B is a sectional view taken along line BB of FIG.
2 is a plan view showing the entire tape carrier of the embodiment of FIG.
FIGS. 2B and 2C are plan views showing the third and fourth embodiments of the sprocket hole shape, FIG. 3A is a plan view showing the entire tape carrier, and FIG. 3B. ) Is a plan view showing the positional deviation of the sprocket hole portion, and FIG. 3 (c) is a sectional view taken along the line CC of FIG. 3 (b). 1a, 1b, 1c, 1d, 1e, 1f, 1g, 1h …… sprocket hall, 2
...... Device hole, 3 ...... Lead frame.

Claims (1)

[Claims] 1. A tape carrier having a device hole, a lead frame, and a sprocket hole, the tape carrier comprising one metal layer, at least the sprocket hole having a first size from one surface of the tape, and the metal. A second opening larger than the first opening from the first opening having a depth equal to or more than half the plate thickness of the layer and the other surface of the tape at the same position as the first opening. And a second opening having a depth that is not less than half the thickness of the metal layer and is smaller than the thickness of the metal layer, and the formation region of the first opening is the first opening. 2. A carrier tape for mounting an integrated circuit, wherein the carrier tape is completely located in the area where the opening 2 is formed.