JPH03214745A - Apparatus for forming bump of tab inner lead - Google Patents

Abstract

PURPOSE:To simplify a bump forming process, reduce a manufacturing cost and improve productivity by a method wherein a hollow bump is formed near the tip part of the inner lead of a TAB tape carrier by a press process. CONSTITUTION:A die 17 having a through hole 18, a punch 19 which pushes a part of an inner lead 11 into the through hole 18 of the die 17 to form a hollow bump 13 and an optical means with which the relative position between the through hole 18 of the die 17 and the punch 19 is monitored are provided. In this case, the dome-shaped hollow bump 13 is formed near the tip part of the inner lead by a mechanical press method with the punch 19 and the die 17 and, further, an enlarging focus system is constituted by a lens 20 provided beneath the through hole 18 of the die 17 and, moreover, the enlarged images of the through hole 18 of the die 17 and the punch 19 are observed on a TV monitor 22 by an ITV provided at a focusing position. With this constitution, a bump forming process can be simplified substantially and the relative position between the punch 19 and the through hole 18 of the die 17 can be set accurately.

Description

[Detailed Description of the Invention] [Field of Application in Industry] The present invention is directed to TAB (Tap) used for mounting semiconductor devices.
e Aul. The present invention relates to an apparatus for forming bumps on the tip of an inner lead of a tape carrier for use in a tape carrier (OMATCD 13 onding).

[Prior Art] Generally, in order to mount a semiconductor element on a TAB tape carrier, it is necessary to form a protrusion that becomes a bump on either the electrode part of the semiconductor element or the inner lead tip of the tape carrier. For example, there are methods for forming bumps on the electrodes of semiconductor devices, such as "IBM Journal (
IBM Journal) Volume 8 (1964)
A method of forming protrusions that will become bumps directly on the electrode portion by plating as described on page +02 [Proceedings of the 1985 IEICE Semiconductor and Materials Division National Conference, Lecture No. 2J
(November 1985), the transfer bump method involves forming bumps on a glass substrate and then transferring the bumps to the electrodes, and
Kaging & Production), 1, 19
As described in the December issue of 1984, pages 33-39, the Bedestal method using etching technology, that is, masking the part where the bump is to be formed and half-etching the other inner lead parts, produces a film of 30 to 40 IIm.
Is there a way to form a protrusion with a height of ? However, forming bumps using these methods not only requires equipment such as expensive exposure equipment and plating equipment, but also lithography and etching processes for patterning, which makes the bump formation process difficult. There is also the issue of longer lengths.

For this reason, as described in Japanese Patent Publication No. 64-10094, a method has been proposed in which a bump is manufactured at the tip of the inner lead using a mechanical press forming technique using a mold. This method is shown in Figure 2 (a), (b), (C).
As shown in the figure, the tape carrier 11 in which the film 12 and the inner lead are integrated is attached to the lower mold 24, and the upper mold 23 having a convex portion 25 larger than the width of the inner lead 11 is lowered from both sides to remove the inner lead. This is a method in which a protrusion (bump) 28 is formed at the tip of the lead l1 by press working. Note that a notch 27 is provided in the width direction to allow material to escape from the recess 15 of the inner lead 1l pressed by the protrusion 28 of the upper die 23.

[Issues that dispatch attempts to solve]

The bumps 28 formed on the tips of the inner leads by the above-described pressing method are bumps with a solid cross-sectional shape obtained by molding the outer shape of the inner leads using a mold. It acts almost as a rigid body against the compressive load applied in the process of joining by crimping. Therefore, if there are variations in the height of individual bumps, when bonding the bumps to the semiconductor element, it is not possible to bond all the bumps uniformly, resulting in a problem of electrical connection failure. In order to prevent connection failures, the variation in bump height should be kept to at least 0.511 m.
It is necessary to satisfy the following conditions, and it is required to form bumps with extremely high precision. In addition, inner lead 11
However, there are problems such as the need to perform processing to create notches in advance.

SUMMARY OF THE INVENTION An object of the present invention is to solve these conventional problems and provide a TAB inner lead bump forming apparatus that requires only a simple forming process.

[Means for Solving the Problems] In order to achieve the above object, in the TAB inner lead bump forming apparatus according to the present invention, a hollow 41l, r is formed by -3 press processing in the vicinity of the inner lead tip of the TAB tape carrier. This device forms bumps with a hollow structure, and includes a die with a through hole, a punch that presses down a part of the inner ribby into the through hole of the die to form a bump with a hollow structure, and a die with a through hole. 1. It has an optical means for optically observing the relative position IyI between the Y through hole and the punch.

[Operation] According to the present invention, a bump having a dome-shaped hollow structure is formed near the inner lead tip ffll by a mechanical pressing method using a punch and a die. Pre-addition for formation]. This has the advantage that the process of forming bumps can be greatly simplified since it is no longer necessary. Moreover, since the bump structure is more easily deformed by compressive force than a solid horizontal structure, even if there is variation in bump height, the bump will be plastically deformed by the compressive load during thermocompression bonding and will be corrected to a uniform height. can do. Therefore, even if there is variation in bump height, it is expected that the bumps can be uniformly densely connected to all 71 pole portions of the hollow bump semiconductor element and that good contact can be achieved. In addition, a magnifying imaging system is configured by a lens placed below the through hole of the die.
Furthermore, an enlarged image of the through hole of the die and the punch can be observed on a TV monitor using the ITV located at the imaging position. Therefore, the relative positions of the through holes of the punch and die can be set accurately, and bumps can be formed on the inner leads with high yield.

【Example〕

Hereinafter, the present invention will be explained in detail using the drawings.

FIG. 1(a) is a schematic diagram showing a bump forming apparatus of the present invention. ``For convenience'' 2, the scale of the component parts is ignored here. FIGS. 1(b) and 1(o) are a plan view and a partially sectional side view showing an embodiment of the bump structure of the inner lead according to the present invention.

In the figure, 11 is an inner lead, and 17 is a through hole 1 at a location that matches the bump formation position at the tip of the inner lead.
The tape carrier with the inner lead II and the plastic film 12 on which the inner lead II and the plastic film 12 are placed is mounted on the die 17''2. Further, a magnifying lens 20 is arranged below the die 17 so as to face the through hole 18, and a television camera (ITV) is placed at the imaging position of the magnifying lens 20.
21, and T~・ on the side where the TV camera 21 comes out.
'A monitor 22 is connected. Here, magnifying lens 20
, a television camera 2+, a TV monitor 22, etc. constitute an optical means for optically observing the relative positional relationship between the through hole of the die and the punch. Before attaching the tape carrier to the die 17, the through hole 18 and the inner lead l1 are aligned. At this time, the magnifying lens 20 constitutes a magnifying imaging system, and the through hole 18 and punch 19 are imaged by a television camera (ITV) 21 placed at the imaging position.
They are simultaneously observed on the V monitor 22. Therefore, as shown in the figure, positioning can be performed by moving the punch 19 or the die 17 so that the enlarged image 19' of the punch 19 overlaps the enlarged image 18' of the through hole 18 on the TV monitor 22. In addition to improving the formation yield, it is possible to significantly reduce the number of alignment steps. After performing the above-mentioned positioning, the inner lead l1 is mounted on the die 17, and the punch l9 is lowered from both sides to mechanically press the inner lead tip, thereby forming the hollow bump 1.
3 formation takes place. For example, punch 1 with an outer diameter of 3011 m
9 with a load of about 80g, width 7 (lpm, thickness 35p)
m copper inner lead 11 (0.5 μm Au on the surface)
Plating treatment and surface roughness are RMAX = O. hm) to form a bump l3.

The hollow bump 13 formed at the center in the width direction of the lead tip has a hollow structure with a space, so the hollow bump 13 has the property of being easily deformed by compression from above, and the bump height Even if there is any unevenness, it can be corrected and joined on the same plane.

In this embodiment, the magnifying imaging system is disposed in one of the die through holes, but the same can be said for both the upper and lower directions. Also,
Although the magnifying imaging system is constructed using a single lens, the same effect can be obtained using a plurality of lenses.

[Effects of the Invention] As described below, according to the present invention, it is possible to form bumps on TAB inner leads with a simple formation process, low manufacturing cost, and high productivity. Furthermore, the number of man-hours required for aligning the die and the punch can be significantly reduced, and the alignment can be performed accurately, which has the effect of improving yield.

[Brief explanation of drawings]

FIG. 1(a) is a schematic diagram showing a bump forming apparatus of the present invention,
(c) is a plan view showing an example of the bump structure of the inner lead according to the present invention, Gc) is a partially sectional side view, and FIGS. It is a figure which shows the bump shape force method using the mechanical press forming process technique used. l...Inner lead 3...Hollow bump 6...Load 8...Through hole 9...Punch 20...Lens 22...TV monitor 24...Lower mold 27...Lead Notch 2...Film 5...Lead recess 7...Dice 8'...Enlarged image of through hole 9'...Enlarged image of punch 21...TV camera 23...Upper die 25 ...Protrusion 28...Bump ○ Hard) (b) (C) Fig. 2

Claims (1)

[Claims] (1) A device that forms a hollow structure bump near the tip of the inner lead of a TAB tape carrier by press processing, which includes a die equipped with a through hole and a part of the inner lead pressed into the through hole of the die. A bump forming device for a TAB inner lead, comprising: a punch for forming a bump having a hollow structure; and an optical means for optically observing the relative positional relationship between the through hole of the die and the punch.