JPH04267352A - Film carrier tape - Google Patents

Abstract

PURPOSE:To make possible to provide a large number of electric selection pads with no restriction of plated wiring by providing the electric selection pads and the lead pattern plated wiring, respectively, on the surface and the rear of a tape. CONSTITUTION:A tape 5a is provided with sprocket holes 1a and device holes 7a through which leads 3a protrude. The leads 3a protruding through the device holes 7a are connected through through-holes 2a with plated lead wires 9a, insulation hole patterns 4a and conductive band patterns 6a. The leads 3a are also connected through the through-holes 2a with electric selection pads 8a provided on the opposite side. Since the plated wiring and the electric selection pads can be formed, respectively, on the surface and the rear of the film carrier tape, the number of the electric selection pads 8a, and thereby the number of the leads, can be increased.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a film carrier tape, and more particularly to a film carrier tape for multiple leads.

0002

2. Description of the Related Art The structure of a conventional film carrier tape is, as shown in FIG. 4, made of an insulating tape 5c made of polyimide film or the like, which has a sprocket hole 1c for conveyance and positioning and a device hole 7c which is an opening into which a semiconductor chip is inserted. A metal foil such as copper is connected to the lead 3c and an electrical selection pad 8c in a desired shape by etching the metal foil or the like. Further, the leads 3c and the electrical selection pads 8c are coated with Au or the like by electrolytic plating to prevent oxidation and stabilize contact resistance. When performing electrolytic plating of Au etc. on the lead 8c and the electrical selection pad 8c, the electrical selection pad 8c is used to conduct current.
Insulation hole pattern 4c via blank plated lead wire 9c
Usually, the conductive band pattern 6c is reached through the conductive band pattern 6c. By doing so, when an electrode roller is applied to the conductive band pattern 6c during electrolytic plating, it can be electrically connected to the leads 3c of the entire film carrier tape, and electrolytic plating can be performed in the form of a tape. When the plating is completed, the insulating hole pattern is mechanically punched and removed using a mold or the like, and each lead 3c and electrical selection pad 8c are electrically insulated, thereby completing a film carrier tape. These film carrier tapes have the advantage that bonding with the semiconductor chip can be performed at once regardless of the leads 3c, so that the speed is high and the work can be easily automated.

0003

[Problems to be Solved by the Invention] The above-mentioned conventional film carrier tape has electrical selection pads and plated lead wires on the same side of the tape, so it is particularly difficult to use when multiple leads and multiple electrical selection pads are required. Naturally, the number of plated lead lines increases and the area occupied on the film carrier also increases. For this reason, there was a problem in that the number of sprocket hole pitches per frame increased and the size of the sprocket holes increased.

0004

[Means for Solving the Problems] The present invention provides a tape having a positioning sprocket hole and a device hole, a lead attached to the tape with one end protruding into the device hole, and a lead connected to the tape. In this film carrier tape, an electrical selection pad is provided on the back side of the surface of the tape on which the lead is attached, and is connected to the lead through a through hole.

[0005]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, the present invention will be explained with reference to the drawings.

FIGS. 1 and 2 are plan views of the front and back surfaces of a film carrier tape according to a first embodiment of the present invention, respectively.

The tape 5a is provided with a sprocket hole 1a and a device hole 7a, and a lead 3a is provided protruding into the device hole. The lead 3a protruding into the device hole 7a extends through the through hole 2a to the plated lead wire 9a, the insulating hole pattern 4a, and the conductive band pattern 6a. Further, the electrical selection pad 8a on the opposite side of the lead 3a is connected to the lead 3a via the through hole 2a.

[0008] Such a film carrier tape having patterns on both sides can be easily manufactured by applying a ground tape commercially available from 3M Company in the United States. For example, first, a polyimide film is selectively etched to form a through hole, then both sides of the polyimide film are thinly coated with Cu by electroless plating, and then Cu is selectively etched.
Electrolytic plating is performed to form a pattern and through-hole plating is performed, and unnecessary thin Cu remaining between the patterns is removed by etching the Cu thinly. Next, sprocket holes 1a and device holes 7a are selectively formed by polyimide etching, and electrolytic plating of Au or the like is applied to the pattern portions to complete the formation of leads 3a, electrical selection pads 8a, and the like. This film carrier tape allows the plating wiring and the electrical selection pad to be formed separately on different sides of the tape, so the electrical selection pad 8
This has the effect of increasing the a number, that is, the number of reads.

FIG. 3 is a plan view of the back side of a second embodiment of the present invention. The through hole 2b can be formed with a diameter of about 50 μm. The electrical selection pad 8c has a contact accuracy of 0.
．． It is said that the size needs to be 5 mm x 0.5 mm or more. Therefore, it is sufficiently possible to provide the through hole 2b in the electrical selection pad 8c, and there is an advantage that the mounting density of the electrical selection pad 8b, etc. can be further increased.

0010

[Effects of the Invention] As explained above, the present invention provides electrical screening pads and lead pattern plating wiring separately on the front and back surfaces of the tape, so electrical screening takes up the largest area on the film carrier tape. It is possible to provide a large number of pads without being restricted by plating wiring, and therefore it is possible to create a film carrier tape compatible with other pins.

[Brief explanation of the drawing]

FIG. 1 is a plan view of the surface of a film carrier tape according to a first embodiment of the present invention.

FIG. 2 is a plan view of the back side of the film carrier tape of the first embodiment of the present invention.

FIG. 3 is a plan view of the back side of a film carrier tape according to a second embodiment of the present invention.

FIG. 4 is a plan view of the surface of a conventional film carrier tape.

[Explanation of symbols]

1a, 1b, 1c Sprocket holes 2a, 2
b Through holes 3a, 3b, 3c Leads 4a, 4c Insulating hole patterns 5a, 5b, 5c Film carrier tape 6a
, 6c Conductive band patterns 7a, 7b, 7c Device holes 8a, 8b,
8c Electrical sorting pad 9a, 9c Plated lead wire

Claims (2)

[Claims] 1. A tape having a positioning sprocket hole and a device hole, a lead attached to the tape with one end protruding into the device hole, and a plated lead wire connected to the lead. 1. A film carrier tape, characterized in that an electrical selection pad is provided on the back side of the surface of the tape on which the lead is attached, and is connected to the lead via a through hole. 2. The film carrier tape of claim 1, wherein the through holes are located in the electrical selection pads.