JP2006198572A - Removal process of anisotropic electric conductive adhesive - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a complete removal method of residue of an anisotropic electric conductive adhesive remaining on a connection terminal part of a substrate, without damaging a lead electrode in a short time in a good working environment. <P>SOLUTION: When removing the anisotropic electric conductive adhesive 12 used for connecting electronic parts to the connection terminal part 11a of the substrate electrically or mechanically, from the connection terminal part 11a, steam heated higher than a glass transition temperature of insulation resin contained in the anisotropic electric conductive adhesive 12, is sprayed to the anisotropic electric conductive adhesive 12. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a technique for removing an anisotropic conductive adhesive left on a connection terminal portion of a substrate by removing an electronic component for repair.

  An anisotropic conductive adhesive is a conductive adhesive in which conductive particles are contained in an insulating resin, and is used when a large number of connection lead terminals are connected together electrically and mechanically. There are a thermosetting type and an ultraviolet curable type, and what is formed into a film is an anisotropic conductive film called ACF (anisotropy conductive film).

  In the liquid crystal display panel, it is used when mounting chip parts to the terminal part or connecting a flexible substrate, but if it is determined that the connection is defective in the inspection after connecting these electronic parts, From the viewpoint of cost and industrial waste countermeasures, the electronic parts once connected are removed and repaired (reused) as much as possible.

  As a problem at the time of repair, electronic parts such as chip parts and flexible substrates can be peeled off from the anisotropic conductive adhesive relatively easily, but the anisotropic conductive adhesive is peeled off even if it is tape-like. It is difficult and often left on the substrate (terminal portion in a liquid crystal display panel) side.

  In order to remove the residue of this anisotropic conductive adhesive, in the invention described in Patent Document 1, an organic solvent such as acetone is applied to the residue of the anisotropic conductive adhesive and swollen, and then the residue is brushed. Rub it with.

JP 2000-197856 A

  However, the removal method according to Patent Document 1 has the following problems. It takes a long time to swell the anisotropic conductive adhesive with an organic solvent (for example, about 3 to 24 hours). Not only that, but also pay attention to time management. That is, if the proper time has not been reached, the swelling will be insufficient, and if the proper time has passed, it will dry. In particular, if peeling is performed with a brush or a spatula in a state where swelling is insufficient, the lead electrode may be damaged due to excessive peeling.

  Further, the amount of the organic solvent applied also becomes a problem in the following points. That is, when a plurality of electronic components are connected to a substrate through continuous ACFs, and one of the electronic components is to be repaired due to poor connection, for example, the organic to the ACF residue left in the repaired portion If the applied amount of the solvent is too large, the organic solvent may penetrate into other normally connected electronic parts, resulting in poor connection. Furthermore, the use of an organic solvent is not preferable because the working environment is deteriorated.

  Therefore, the object of the present invention is to perform a good operation without using an organic solvent and without causing a risk of damaging the lead electrode in a short time with the residue of the anisotropic conductive adhesive remaining on the connection terminal portion of the substrate. It is to be able to remove it cleanly in the environment.

  In order to solve the above problems, the invention according to claim 1 is directed to connecting the anisotropic conductive adhesive used for electrically and mechanically connecting an electronic component to the connection terminal portion of the substrate. In the method for removing the anisotropic conductive adhesive removed from the part, the anisotropic conductive adhesive was heated to a temperature higher than the glass transition temperature of the insulating resin contained in the anisotropic conductive adhesive. It is characterized by spraying water vapor.

  The invention described in claim 2 is the method according to claim 1, wherein when the water vapor is sprayed onto the anisotropic conductive adhesive, the anisotropic conductive adhesive to be removed is surrounded by a cylindrical frame. It is characterized by.

  The invention according to claim 3 is the invention according to claim 2, wherein the anisotropic conductive adhesive is non-contacted along the at least a pair of opposing inner wall surfaces in the frame body, and the inner A partition plate that forms a predetermined gap is provided between the wall surface and the water vapor is blown from between the partition plate and the inner wall surface of the frame.

  According to the invention described in claim 1, by spraying water vapor heated above the glass transition temperature of the insulating resin against the anisotropic conductive adhesive, the anisotropic conductive adhesive is softened, Since the adhesive force at the interface between the substrate and the anisotropic conductive adhesive is weakened, the anisotropic conductive adhesive can be wiped clean with a cotton swab or the like. Moreover, since it is water vapor | steam, a work environment does not deteriorate.

  According to the invention of claim 2, when the steam is sprayed on the anisotropic conductive adhesive, the anisotropic conductive adhesive to be removed is surrounded by a cylindrical frame. It can be used, and the effect of claim 1 can be further enhanced, and water containing residue does not leak out. Therefore, when electronic components are arranged adjacent to each other, the electronic components are adversely affected. Nor.

  In addition, a partition plate that is non-contact with the anisotropic conductive adhesive and forms a predetermined gap between the inner wall surfaces along at least a pair of opposed inner wall surfaces in the frame body is provided. According to the invention of claim 3, wherein water vapor is blown from the space between the partition plate and the inner wall surface of the frame body. Can be maximized.

  Next, an embodiment of the present invention will be described with reference to FIGS. 1 to 3, but the present invention is not limited to this.

  The present invention relates to the anisotropic conductive adhesive remaining on the connection terminal portion of the substrate with water vapor heated above the glass transition temperature of the insulating resin contained in the anisotropic conductive adhesive. Although it is characterized by spraying, in the description of this embodiment, water vapor heated to the above temperature is referred to as high-temperature water vapor. It is preferable to use pure water or ultrapure water as the high-temperature steam.

  FIG. 1 shows a liquid crystal display panel 10 as an example of a connection terminal portion of a substrate having an anisotropic conductive adhesive removed by this high temperature water vapor. The liquid crystal display panel 10 includes a pair of transparent electrode substrates 11 and 12 that are bonded together via a peripheral sealing material (not shown) and encapsulated with a liquid crystal substance. A connection terminal portion is provided on one of the transparent electrode substrates 11. 11a is continuously provided.

  Although not shown, the connection terminal portion 11a is formed with a lead electrode connected to the transparent electrode in the panel in a strip shape. In this example, the lead electrode is connected to the liquid crystal drive via the anisotropic conductive film 12. In this case, the bare chip arranged at the center thereof is determined as a connection failure by inspection after connection, and is removed from the anisotropic conductive film 12. Therefore, the portion indicated by A in FIG. 1 is the repair target portion.

  In the present invention, an anisotropic conductive adhesive may be used instead of the anisotropic conductive film 12. The insulating resin contained in the anisotropic conductive adhesive may be either a thermosetting type or an ultraviolet curable type.

  When spraying high temperature steam on the anisotropic conductive film 12 of the repair target portion A, it is preferable to use a cylindrical frame 20 shown in FIG. The frame 20 has a size surrounding the repair target portion A, and a lower end thereof is provided with a seal leg 21 made of, for example, silicone rubber for the purpose of preventing water leakage from the frame.

  In addition, as in this example, when peeling only a part of the anisotropic conductive film 12 having a tape shape (repair target part A), the width of the frame body 20 is wider than the width of the anisotropic conductive film 12, As shown in FIG. 3, it is preferable that both end surfaces 12a and 12a of the anisotropic conductive film 12 are exposed to high-temperature steam.

  More preferably, a partition plate 22 for spraying high-temperature water vapor toward both end faces 12 a and 12 a of the anisotropic conductive film 12 is provided in the frame body 20. That is, a predetermined gap is formed between at least a pair of opposed inner wall surfaces in the frame body 20, in this example, the inner wall surfaces 20a and 20a disposed along both end surfaces 12a and 12a of the anisotropic conductive film 12. The partition plates 22 and 22 are provided, and high-temperature steam is blown through the gaps. As shown in FIG. 2, the partition plate 22 may be formed as an inner frame facing the four inner wall surfaces of the frame body 20.

  When high temperature water vapor is applied to the anisotropic conductive film 12, the anisotropic conductive film 12 starts to soften, thereby reducing the adhesive force at the interface between the anisotropic conductive film 12 and the connection terminal portion 11a.

  Further, as the anisotropic conductive film 12 is softened, high-temperature steam easily enters the interface, and the adhesive strength is further weakened. This is because the adhesion mechanism is due to hydrogen bonds, and the hydrogen bonds are broken by moisture. In this sense, it is preferable that the high-pressure steam spray pressure on the anisotropic conductive film 12 is higher.

  As described above, according to the present invention, the anisotropic conductive film 12 is softened by spraying high-temperature water vapor, and the adhesive strength with the connection terminal portion 11a is weakened. The anisotropic conductive film 12 of A can be easily and cleanly peeled off. In most cases, the removal operation can be completed in about 3 to 10 minutes.

  In addition, by using the frame 20, when another bare chip 13 that is normally connected adjacent to the repair target portion A is arranged as shown in FIG. 1, the other bare chip 13 is adversely affected. I don't give it.

  Furthermore, by providing a partition plate 22 in the frame body 20 and concentrating and spraying high-temperature water vapor on both end faces 12a and 12a of the anisotropic conductive film 12, as shown in FIG. Peeling of the conductive film 12 can be further promoted.

  The present invention is not limited to the liquid crystal display panel described in the above embodiment, but in the field of connecting electronic components such as chip components and flexible substrates to the connection terminal portions of the substrate via an anisotropic conductive adhesive. Therefore, it can be used for all cases where the anisotropic conductive adhesive is removed from the connection terminal portion.

The perspective view which shows the connection terminal part of the liquid crystal display panel which has a repair part for description of embodiment of this invention. The perspective view which shows an example of the frame body preferably used by this invention. The typical sectional view for explaining the operation of the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Liquid crystal display panel 11a Connection terminal part 12 Anisotropic conductive film 13 Bare chip 20 Frame 21 Seal leg 22 Partition plate A Repair part

Claims (3)

In the anisotropic conductive adhesive removal method of removing the anisotropic conductive adhesive used to electrically and mechanically connect the electronic component to the connection terminal portion of the substrate from the connection terminal portion of the substrate,
The anisotropic conductive adhesive is characterized in that water vapor heated to a temperature higher than the glass transition temperature of the insulating resin contained in the anisotropic conductive adhesive is sprayed on the anisotropic conductive adhesive. Removal method.   2. The anisotropic conductive adhesive according to claim 1, wherein when the water vapor is sprayed on the anisotropic conductive adhesive, the anisotropic conductive adhesive to be removed is surrounded by a cylindrical frame. Material removal method.   A partition plate that is non-contacting with the anisotropic conductive adhesive and forms a predetermined gap with the inner wall surface along at least a pair of opposed inner wall surfaces in the frame body, The method for removing an anisotropic conductive adhesive according to claim 2, wherein water vapor is blown from between the partition plate and the inner wall surface of the frame.

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