JPH0344048A - Carrier tape for tab type semiconductor device - Google Patents

Abstract

PURPOSE:To obtain a carrier tape for a TAB use capable of precisely measuring the thickness of plating, by making the width of an electrode leading-out pattern on a polyimide tape nearly equal to the widths of a lead tip part and an OLB part, and arranging non-plated floating pattern in the part adjacent to the above pattern. CONSTITUTION:An electrode leading-out pattern 4 whose width is nearly equal to the lead widths of a lead tip part 2 and an OLB part 3 is arranged, and on both sides of said pattern, a floating pattern A 6a and a floating pattern B 6b are formed, which are electrically floated and not subjected to electroplating. When the width of the lead tip part 2 is different from that of the electrode leading-out pattern 4 in the case of plating a lead 1, the plating depths are different from each other because of the difference of current density. Hence the width of the electrode leading-out pattern 4 is made equal to the widths of the lead tip part 2 and the OLB part 3. Further, since there are the floating patterns A 6a and B 6b without being plated on both sides, the plating thickness can be easily confirmed by measuring and comparing both of them and obtaining the difference.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a TAB (tape automated bonding) type carrier tape for semiconductor devices.

[Conventional technology]

Conventional carrier tapes are formed by etching polyimide tape or the like, as shown in Figure 3.
The lead 1 consists of a lead tip 2 for bonding an IC chip, an OLB part (outer lead bonding part) 3 for mounting on a substrate, and an electrode extraction pattern 4. Further, these lead groups are continuously and repeatedly formed on the tape to form a carrier tape in order to carry out the bonding of IC chips by automatic feeding.

Further, when these leads 1 are formed by etching on the carrier tape, they are connected to the plating current supply common pattern 7 by the lead-specific plating current supply pattern 8, and are electrically conductive.

After etching, plating current is supplied from the plating current supply common pattern 7 using the lead 1 side as one electrode, and electrolytic plating is performed, whereby the lead 1 is plated for bonding ink for mounting on an IC chip or board. administered.

[Problem to be solved by the invention]

The leads are bonded to the IC chip or substrate by thermocompression bonding. Conditional parameters when performing thermocompression bonding include the force, temperature, and time during compression, but as a prerequisite, it is essential that the thickness of the lead plating be constant.

If the lead plating thickness varies widely, even if bonding is performed under specified conditions, the bonding strength may be insufficient, and if a cracking condition occurs, the reliability of the equipment used will decrease. . In order to obtain a lead with a constant plating thickness, it goes without saying that the conditions during plating must be stable, but ultimately it is necessary to measure the plating thickness.

However, the above-mentioned conventional carrier tape has the disadvantage that all the leads are plated and it is difficult to easily measure the plating thickness.

In other words, the conventional method of measuring the plating thickness of tape leads is to cut the leads, observe the cross section, and measure the plating thickness. It is also difficult to measure large numbers of leads.

Another option is to use a mechanical measuring device such as a dial gauge to measure the thickness of the lead before and after plating, but the width of the lead is generally about 1.00 μm and difficult to measure. Furthermore, although it is possible to measure the thickness before and after plating at a large area with a width of several mm, such as the plating current supply common pattern, it is difficult to measure the plating thickness between the lead tip and the OCB part due to the difference in plating current density. are different,
It is not possible to determine the exact plating thickness at the required location.

An object of the present invention is to provide a carrier tape for a TAB type semiconductor device that allows measurement of lead plating thickness and provides highly reliable bonding.

[Means to solve the problem]

The present invention provides a carrier tape for a TAB type semiconductor device that includes a lead coated with at least one layer of plating and having an electrode extraction pattern whose width is the same as that of the lead tip and the outer lead bonding part. At least ↑ unplated floating patterns are provided in the vicinity of the leads and formed at the same time as the leads.

〔Example〕

Next, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 shows a first embodiment of the invention.

In the first embodiment, as shown in FIG.
There is a conductive pattern that forms a lead 1 that connects to an OLBL12 type electrode lead pattern 4 and an electrode 5, and along that line, there is a conductive pattern that forms a lead tip 2 and an electrode lead pattern with a width that is about the same as the OLBL12 type electrode width. 4, and floating patterns A6a and B6b, which are electrically floating and are not electrolytically plated, are provided on both sides thereof.

In plating lead 1, lead 1 formed on the carrier tape is connected to plating current supply common pattern 7 by lead-specific plating current supply pattern 8, and electrolytic plating 1
Plating current is supplied as two electrodes 5, but if the widths of the lead tip 2 and the electrode extraction pattern 4 are different, the plating thickness will be different due to the difference in current density. The width of the turns is the same.

Furthermore, in this state, since there are floating patterns A6a and B6b without plating on both sides, the plating thickness can be easily determined by comparing and measuring the two to determine the difference in thickness. The difference in plating thickness can be sufficiently measured using a measuring device of the current state of the art, such as a laser beam reflection method.

Further, since the floating patterns A6a and B6b are provided on both sides of the electrode extraction pattern 4, it is possible to detect errors when the polyimide tape 9 serving as a substrate during thickness measurement has an inclination.

FIG. 2 is a plan view of a second embodiment of the invention.

In the second embodiment, as shown in FIG.
Two electrode extraction patterns 4 having the same width as the OLB part 3 are provided, and a floating pattern 6 is provided between them.
By positioning C, the plating thickness can be measured from the difference in thickness between the plated electrode lead pattern 4 and the unplated floating pattern 6C.

In this embodiment, if the polyimide tape 9 is tilted, there will be a difference in thickness between the electrode lead patterns 4 on both sides of the floating pattern 6C, which can be detected.

〔Effect of the invention〕

As discussed above, the present invention makes the electrode extraction pattern on the polyimide tape about the same width as the lead tip and OLB part, and furthermore, provides a floating pattern without plating next to it, making it easy to use. It is possible to obtain a TAB carrier tape that can measure plating thickness with high precision.

In particular, the carrier tape for TAB is, for example, 100m long.
Leads are formed continuously on a polyimide tape of approximately 300 mm length, so by automatically feeding this polyimide tape, the thickness of the lead plating at all positions on the tape can be automatically measured, making it reliable. This has the effect of making it possible to obtain carrier tape with high properties.

[Brief explanation of drawings]

Figure 2 is a plan view of the first embodiment of the present invention, Figure 2 is a plan view of the second embodiment of the present invention, and Figure 3 is a plane view of an example of a conventional carrier tape for TAB type semiconductor devices. It is a diagram.

Claims (1)

[Claims] A carrier tape for a TAB type semiconductor device has a lead coated with at least one layer of plating and has an electrode lead-out pattern whose width is equal to the width of the lead tip and outer lead bonding part, and the lead is plated with at least one layer. A carrier tape for a TAB type semiconductor device, characterized in that at least one unplated floating pattern is formed adjacent to the lead at the same time as the lead.