JP4488073B2 - Electrical connection device - Google Patents

Description

  The present invention relates to an electrical connection device, and more particularly to an electrical connection device that can be suitably used for connection between a COF wiring board incorporating a semiconductor package and a thin monitor panel board.

  Thin panels typified by flat-screen televisions are strongly required to reduce costs due to recent price competition as well as larger panels and higher image quality. For this reason, driver ICs mounted on a panel are becoming smaller in size due to an increase in the number of output signals and an increase in density. Against this background, the wiring of a COF (Chip On Film) wiring board used when mounting an IC chip on a panel is also strongly required to be miniaturized and highly accurate. The COF wiring board is a film-like wiring board that connects the IC chip and the panel, and the IC chip is first mounted on the COF wiring board. Thereafter, the COF wiring board on which the IC chip is mounted is mounted on the panel.

In general, such a wiring material for a COF wiring board is formed by forming a metallized layer by a so-called subtractive method of forming a wiring pattern by etching a copper foil formed on a polyimide film, a sputtering method or the like on a polyimide film, It is manufactured by a semi-additive method or the like in which a photoresist pattern is formed thereon and a wiring pattern is obtained by filling the opening of the resist pattern by plating.
As shown in FIG. 3, the COF wiring board manufactured by these methods includes inner leads connected to the IC chip, outer leads arranged in parallel to one end surface of the board and connected to the panel board, wiring A test pad is formed to check the disconnection and short circuit and to perform an operation test of the mounted IC chip.

  In such a COF wiring board, the inner lead and the electrode of the IC chip are joined, and then the resin sealing for protecting the IC chip and the joint is performed, and then the operation test of the IC chip is performed and the die punching is performed. Unnecessary portions are cut and removed by, for example. After that, by aligning the outer lead and the electrode of the panel substrate and thermocompression bonding using an ACF (Anisotropic Conductive Film), the electrical connection and adhesion between the outer lead and the panel substrate are simultaneously performed. Do.

In the conventional COF wiring board, the outer leads for connecting to the panel substrate are arranged in parallel, and in order to ensure electrical connection by ACF and not to short-circuit adjacent electrodes and outer leads, the outer leads The wiring width is 15 μm or more, and the space between the outer leads is required to be at least 20 to 25 μm.
For this reason, it is necessary to secure an area for arranging the outer leads, which is a limitation of downsizing the COF wiring board. In particular, the increase in the number of output signals of the IC chip in recent years has increased the number of outer leads, making it more difficult to reduce the cost by downsizing the COF wiring board and reducing the board area.

In general, the inner leads of the COF wiring board have finer pitches than the outer leads. For example, the semi-additive method can cope with fine pitches of 20 μm or less. The limit was around 35-40 μm pitch.
Furthermore, the expansion of the overall width of the outer leads due to the increase in the number of outer leads increases the lead position deviation at the time of thermocompression bonding due to the thermal expansion of the film, making it difficult to refine the outer lead pitch.

  As a method for solving such a problem, for example, a method disclosed in Patent Document 1 has been proposed. In this proposal, the first substrate on which the first wiring pattern having a plurality of lands is formed and the second substrate on which the second wiring pattern is formed are electrically connected, A plurality of lands having a shape wider than the first wiring width are arranged in a row on one substrate, and adjacent lands are arranged in a staggered manner. When the first substrate and the second substrate are connected, these lands are connected in an overlapping state with the electrical connection portion formed in the second wiring pattern. An insulating layer is formed between the portion other than the electrical connection portion and the first wiring pattern.

As described above, according to the configuration proposed in Patent Document 1, the lands formed on the first substrate are arranged in a zigzag pattern, so that the apparent connection pitch can be widened and alignment is performed with high accuracy. Since it is not necessary, it can be determined that the connection pitch can be substantially refined.
However, on the other hand, it is necessary to form a protruding electrode at the electrical connection part on the second substrate, and to protect other parts than the electrical connection part with an insulating protective film in order to prevent a short circuit with the adjacent wiring or land Met. The formation of these protruding electrodes and the protection by the insulating protective film are not necessary for the connection between the conventional panel substrate and the COF wiring substrate, which results in an increase in the number of processes and an increase in manufacturing cost. .
JP 2003-332380 A

  The present invention has been made to solve such problems. The object of the present invention is to use a connection method that is not different from the conventional method for connecting to a panel substrate, and to refine the connection pitch with the panel substrate. It is possible to provide a small and low-cost electrical connection device.

  The electrical connection device according to the present invention includes a COF wiring board including a plurality of first electrode pad parts and routing wirings connected to the electrode pad parts, and the COF wiring board that is superposed on the COF wiring board. An electrical connection device comprising: a plurality of second electrode pad portions respectively joined to the plurality of first electrode pad portions; and a panel substrate including a lead wiring connected to each of the electrode pad portions. Each of the first electrode pad portions is formed in a square pattern in a staggered arrangement, and the routing wiring extends in parallel in the opposite direction with a predetermined width from each diagonal position across the first electrode pad portions, The plurality of second electrode pad portions are respectively formed in a staggered manner in a square shape, and the routing wiring is opposite to the diagonal position of the second electrode pad portion with a predetermined width. Characterized in that it extends parallel to the direction.

  In addition, the electrical connection device according to the present invention has a COF wiring substrate including a plurality of first electrode pad portions and routing wirings connected to the electrode pad portions, and is polymerized so as to face the COF wiring substrate. An electrical connection device comprising a plurality of second electrode pad portions respectively joined to the plurality of first electrode pad portions, and a panel substrate including routing wiring connected to each electrode pad portion, The plurality of first electrode pad portions are respectively formed in a staggered manner in a square shape, and the routing wiring is concentric with the first electrode pad portions from the first electrode pad portions and opposite to each other with a predetermined width. The plurality of second electrode pad portions are formed in a square shape in a staggered arrangement, and the routing wiring extends from the second electrode pad portions to the second electrode pad portions. Concentrically respectively with a predetermined width, characterized in that it extends parallel to the opposite direction.

  In the electrical connection device according to the present invention, the width of each of the first electrode pad portions is in the range of 15 to 100 μm, and the width of the lead wiring connected to the first electrode pad portion is in the range of 5 to 20 μm. And an interval between the adjacent first electrode pad portion and the lead wiring is at least 20 μm or more.

  In the electrical connection device according to the present invention, the width of each of the second electrode pad portions is 15 to 40 μm, and is formed wider than the width of the routing wiring connected to the second electrode pad portion. The width of the routing wiring is in the range of 10 to 25 μm at least in a region overlapping with the COF substrate, and is formed with a width narrower than that of the second electrode pad portion. And at least 20 μm or more between the routing wiring and the routing wiring.

  With the above configuration, the electrode pad for ACF connection can maintain the lead width necessary for the connection, and the wiring width other than the electrode pad can be made narrower than the minimum lead width required for the ACF connection. Fine pitch can be achieved while maintaining a sufficient space between wires. Further, with the above-described configuration, the connection between the panel substrate having a large number of connection points and the COF wiring substrate can be made with a finer pitch than before, and the film width of the COF can be reduced.

According to the present invention, the bonding between the COF wiring board and the panel board is performed by arranging the bonding pads having a wide width only in the area where the ACF connection is required in a staggered manner, so that the bonding pads are arranged in parallel. It is easier to make the connecting portion fine pitch than the case. Furthermore, since the routing wiring that does not need to be bonded can be made thinner than the minimum lead width required for the ACF connection, the space adjacent to the bonding pad can be widened.
In addition, since the entire width of the joint portion can be made narrower than in the case of the conventional configuration, it is less susceptible to film thermal expansion due to thermocompression bonding, and a highly reliable panel-mounted COF wiring board with little misalignment of the joint position can be provided.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
1 (a) and 2 (a) are partially enlarged views showing different embodiments of the electrode pad portion on the COF wiring board side used in the electrical connection device according to the present invention, and FIG. 1 (b) and FIG. (B) is an enlarged view which shows mutually different embodiment of the electrode pad part by the side of the panel board | substrate used for the electrical-connection apparatus based on this invention.

  In the first embodiment of the present invention, as shown in FIG. 1 (a), electrode pads 1a are formed in a staggered pattern in the region where the outer leads of the conventional COF wiring board 1 as shown in FIG. 3 are formed. At the same time, when the electrode pad portion 2a is formed on the panel substrate 2 as shown in FIG. 1B and the COF wiring substrate 1 and the panel substrate 2 are overlapped with each other, the electrode pad portions 1a, 2a of the both are formed. The electrode patterns of the COF wiring substrate 1 and the panel substrate 2 are configured so as to be bonded.

According to the present invention, the electrode pad portion 1a of the COF wiring board 1 is formed in the external connection portion on the output side of the mounted IC, and the width of the electrode pad portion 1a is wide as shown in FIG. The routing wiring portion 1b is formed thin. The width of the electrode pad portion 1a is set to a width in the range of 15 to 40 μm that is necessary for ACF bonding, and the length of the electrode pad portion 1a is set so that the area of the electrode pad portion 1a is at least 1500 μm ² or more. Is selected. This is because if the width of the electrode pad portion 1a is increased to 40 μm or more, the pad pitch is increased, and the merit of fine pitch is lost.

  The routing wiring 1b does not need to be joined, and it is desirable to form it with a width of 25 μm or less in order to realize a joining pitch of 35 μm or less, which has conventionally been considered difficult while securing a space. However, if the wiring 1b is too thin, the adhesion strength of the wiring is reduced, and the wiring is easily peeled off during ACF connection. Therefore, the width of the routing wiring 1b is preferably selected in the range of 10 to 25 μm.

FIG. 2 shows a second embodiment of the present invention. This embodiment is different from the first embodiment in that the electrode pad portion 1a and the wiring 1b are formed concentrically and the wiring 1b is arranged at equal intervals. Also in the present embodiment, the dimensions of the electrode pad portion 1a and the width of the lead wiring 1b are selected in the same manner as in the first embodiment.
The arrangement according to the second embodiment is more advantageous for the fine pitch than the first embodiment, and even when an evenly spaced arrangement as shown in FIG. 3 is desired, the effect of the fine pitch can be obtained. Can do.

  Thus, in the COF wiring board 1, for example, when the electrode pad portion 1 a has a width of 15 μm, the routing wiring 1 b has a width of 10 μm, and the interval between adjacent wirings 1 b has been selected to be 20 μm, The average pitch of the pad portions 1a can be 31.7 μm in the first embodiment and 32.5 μm in the second embodiment.

  In addition, the electrode pad portion 2a of the panel substrate 2 may be formed in the same manner as the electrode pad portion 1a of the COF wiring substrate 1, but the electrode pad portion 2a of the panel substrate 2 is formed of the electrode pad portion of the COF wiring substrate 1. In order to be bonded in the direction facing the portion 1a, the arrangement of the electrode pad portions 2a and the routing wiring 2b are made to be bilaterally symmetric, and are formed so as to overlap each other at the time of bonding.

  The COF wiring substrate 1 and the panel substrate 2 obtained as described above are aligned by a method similar to the conventional method, and are electrically connected by thermocompression bonding with an ACF interposed.

  As is clear from the above description, according to the electrical connection device of the present invention, the electrode pad portion is formed on both the COF wiring substrate 1 and the panel substrate 2, and the routing wiring other than the electrode pad portion is formed thin. Thus, it is possible to achieve both the required width of the joint and the securing of the space.

The table below shows the number of electrical connection points by the conventional method of forming outer leads and the maximum number of electrical connection points that can be formed on a 48 mm wide (effective width 42 mm) film according to the present invention.

  In addition, according to the present invention, since the bonding pad portions can be arranged in two or more rows as compared with the conventional method in which the outer leads are arranged in parallel in one row, more joint portions can be formed within the same width. If the number of joints is the same, the width of the film used can be made narrower than before. Since the film width can be narrowed, the amount of film expansion due to thermal expansion is reduced, and the displacement of the bonding pad portions at both ends which are particularly susceptible to influence is also reduced.

Example 1
Hereinafter, a method of manufacturing the COF wiring board according to the present embodiment will be described with reference to FIG.
The COF wiring substrate 1 used in this example is a polyimide film (Ube Industries Upilex) having a thickness of 35 μm as a base film material, and a Cu wiring pattern having a thickness of 8 μm is formed by a semi-additive method. The surface of the film was subjected to Sn plating with a thickness of 0.2 μm.
The electrode pad portion 1a of the COF wiring board 1 is formed in the arrangement shown in FIG. 1A having a pad width of 15 μm, a pad length of 1000 μm, a space width (wiring interval) of 20 μm, and a lead wiring width of 10 μm.
On the other hand, a quartz glass plate having a thickness of 1 mm is used for the panel substrate 2, and an electrode pad portion 2 a having an array shown in FIG. Was formed of aluminum.
The obtained COF wiring board 1 and the panel board 2 were aligned, and 50 samples were thermocompression bonded using a 25 μm-thick ACF film under the conditions of a temperature of 150 ° C. and 15 seconds, and an electrical check was performed. There was no connection failure.

Example 2
Hereinafter, the method for manufacturing the COF wiring board according to the present embodiment will be described with reference to FIG.
The COF wiring board 1 used in this example is a polyimide film (Ube Industries Upilex) whose base film material is 35 μm thick, and a Cu wiring pattern having a thickness of 8 μm is formed by a semi-additive method. The surface is subjected to Sn plating with a thickness of 0.2 μm.
The electrode pad portion 1a of the COF wiring board 1 was formed in the arrangement shown in FIG. 2A, having a pad width of 15 μm, a pad length of 1000 μm, a space width of 20 μm, and a lead wiring width of 10 μm. On the other hand, a quartz glass plate having a thickness of 1 mm is used as the panel substrate 2, and an electrode pad portion 2a having the arrangement shown in FIG. 2B and having a pad width of 15 μm, a pad length of 1000 μm, a space width of 20 μm, and a routing wiring width of 10 μm. Made of aluminum.
The obtained COF wiring board 1 and panel board 2 were aligned, and 50 samples were thermocompression bonded using a 25 μm-thick ACF film under conditions of a temperature of 150 ° C. for 15 seconds, and an electrical check was performed. There was no connection failure.

(A) And (b) is the elements on larger scale which show 1st embodiment of the electrode pad part of the COF wiring board used for the electrical connection apparatus which concerns on this invention, and a panel board | substrate. (A) And (b) is the elements on larger scale which show 2nd embodiment of the electrode pad part by the side of the COF wiring board and panel board | substrate used for the electrical-connection apparatus based on this invention. It is a top view which shows an example of the conventional COF wiring board.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 COF wiring board 1a Electrode pad part 1b Lead wiring 2 Panel board 2a Electrode pad part 2b Lead wiring

Claims (4)

  A COF wiring board including a plurality of first electrode pad parts and routing wirings connected to the electrode pad parts, and the plurality of first electrode pad parts when superposed on the COF wiring board. And a panel substrate including a plurality of second electrode pad portions to be joined to each other and routing wires connected to the respective electrode pad portions, wherein the plurality of first electrode pad portions include: A plurality of second electrode pads are formed in a staggered arrangement in a square shape, and the routing wirings extend in parallel in opposite directions with a predetermined width from the diagonal positions across the first electrode pad portions. The portions are formed in a square pattern in a staggered arrangement, and the routing wirings extend in parallel in opposite directions with a predetermined width from the diagonal positions across the second electrode pad portions. Electrical connection device according to claim.   A COF wiring board including a plurality of first electrode pad parts and routing wirings connected to the electrode pad parts, and the plurality of first electrode pad parts when superposed on the COF wiring board. And a panel substrate including a plurality of second electrode pad portions to be joined to each other and routing wires connected to the respective electrode pad portions, wherein the plurality of first electrode pad portions include: Each of the routing wirings is formed in a staggered arrangement in a square shape, and extends in parallel in the opposite direction with a predetermined width from each of the first electrode pad portions concentrically with each of the first electrode pad portions. The second electrode pad portions are respectively formed in a square pattern in a staggered arrangement, and the routing wiring is concentric from the second electrode pad portions to the second electrode pad portions with a predetermined width. Electrical connection device, characterized in that running parallel to the direction.   The width of each of the first electrode pad portions is in the range of 15 to 100 μm, the width of the routing wiring connected to the first electrode pad portion is in the range of 5 to 20 μm, and the adjacent first electrodes The electrical connection device according to claim 1 or 2, wherein an interval between the pad portion and the routing wiring is at least 20 µm or more.   The width of each of the second electrode pad portions is 15 to 40 μm, and is formed wider than the width of the routing wiring connected to the second electrode pad portion, and the width of the routing wiring is at least the width of the routing wiring In the region overlapping with the COF substrate, the width is in the range of 10 to 25 μm and is narrower than the second electrode pad portion, and the distance between the second electrode pad portion and the routing wiring is at least 20 μm. It is the above, The electrical connection apparatus of Claim 1 or 2 characterized by the above-mentioned.