JPH06223945A - Repairing method for circuit junction - Google Patents

Abstract

PURPOSE:To perform the homogeneous removing work in a short time, improve the repairing work of reconnection, and improve reliability by applying a peeling liquid to only the portion requiring the removal of an adhesive, and utilizing the mechanical grinding work of a buff rotor. CONSTITUTION:When a TAB substrate 2 is peeled while the ITO circuit 5 of a glass substrate 1 and the circuit 6 of the TAB substrate 2 are connected via an anisotropic conducting adhesive 3, a buff rotor 4 impregnated with a dissolving agent is mounted on the adhesive to be removed. The buff rotor 4 is rotated to remove the adhesive, then the adhesive 3 is wiped and completely removed by another buff rotor impregnated with methanol to expose an ITO circuit 5, and a new TAB circuit is reconnected to it. The adhesive 3 can be precisely removed in a short time, and the reliability of reconnection can be improved.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for repairing a circuit connecting portion.

[0002]

2. Description of the Related Art With the miniaturization and thinning of electronic parts, circuits used for them have become higher in density and higher in definition. Since it is difficult to connect these fine circuits with conventional solder or rubber connectors, recently, anisotropic conductive adhesives and film-like materials (hereinafter referred to as connecting members) have been used frequently. Came. In this method, a connecting member layer made of an adhesive containing a predetermined amount of a conductive material is provided between the circuits facing each other, and pressing or heating / pressurizing means is provided so that the upper and lower circuits are electrically connected at the same time. Insulation is provided between the circuits, and the circuits facing each other are fixed by adhesion.

As a prior art relating to an anisotropically conductive film-like molded article having conductivity only in the thickness direction, conductive particles are made non-conductive as disclosed in, for example, Japanese Patent Application Laid-Open No. 51-21192. There is a structure in which a resin is held in a state where it does not contact with each other, and the composition has a structure having conductivity only in the thickness direction of a sheet having a thickness substantially equal to the size of the conductive particles. In addition, an attempt has been made to connect the opposing circuits by adhering and fixing them in a contact state with an insulating adhesive having no conductive particles (for example, Japanese Patent Publication No. 46-43732).

In the connection with these connecting members, when the electrical connection is defective, or the electronic parts or circuits become defective after the connection, the circuits are separated by peeling, and the connecting member is removed with a solvent or the like. A method is used in which the non-defective product is connected again by the connecting member (hereinafter referred to as “reconnection”) after the removal by (1). In addition, when connecting the housing or other parts to the electronic component having the unconnected circuit part with the adhesive, even if the adhesive adheres to the unconnected circuit part and the subsequent connection becomes difficult, the solvent A method such as wiping with a cloth or cotton swab impregnated with the above is used.

[0005]

However, in the above-mentioned method of removing the adhesive, it takes a long time for the work and it is extremely difficult to remove the adhesive partially. For example, an anisotropic conductive connecting member is also used for connecting a large number of electronic components to a single large electronic component having a large number of circuits. Since it is a manual work while paying attention not to adversely affect it, the above-mentioned adhesive removal method requires a long time and affects other connection members, resulting in poor connection and reduced reliability. was there.

For example, as shown in FIG. 1 (a), an ITO (Indium tin Oxide) circuit on a glass substrate 1 and a large number of circuits, which is a general method for connecting electronic components used in liquid crystal display materials, are used. When the TAB (Tape Automated Bonding) circuit 2 is connected by an anisotropic conductive connection member, these circuits have, for example, a conductor width composing the circuit of 100 μm.
m, a high-definition circuit with a width between conductors of 100 μm is used, and the distance between conductors between adjacent TAB circuits is several hundred μm as electronic parts become lighter, thinner and smaller.
There is a case to connect up to. Here, FIG.
In order to replace and reconnect one of the TAB circuits 2 shown in (a), the TAB circuit is peeled off, and the connecting member on the glass substrate is made of a cotton swab impregnated with the above-mentioned conventional peeling solution. In the method of wiping the adhered connecting member, and disassembling or dissolving it, it takes about 3 minutes to remove one TAB, and the number of processed sheets is large, so that the yield of the entire connecting work is reduced. was there. Also, the adjacent T
There is also a problem that even the connecting members of the AB circuit are disassembled or dissolved, leading to an increase in connection resistance and a decrease in connection reliability.

[0007]

SUMMARY OF THE INVENTION The present invention has been made in view of the above situation, and (1) peels off the joint portions of the connection portions requiring repair,
A step of placing a buff rotor having a predetermined shape on the adhesive surface remaining on at least one circuit surface. (2) A step of temporarily contacting the peeling liquid with the adhesive by impregnating the buffing rotor with the peeling liquid. (3) A step of cleaning the circuit surface in contact with the buff rotor impregnated with the stripping solution. (4) A step of reconnecting the circuit surface of the other circuit board to the cleaned circuit surface with an adhesive. And a method for repairing a circuit connecting member. That is, according to the present invention, the peeling liquid is applied only to the portion where the adhesive needs to be removed, and the mechanical grinding action of the buff rotor enables a uniform and uniform adhesive removal work in a short time, thereby ensuring the reliability of reconnection. It is a method of repairing circuit connection parts that can significantly improve the performance.

The present invention will be described in detail below. The buff rotor used in the present invention is a fibrous material having fine voids, and is not particularly limited as long as it has a property that the peeling liquid permeates the entire buff rotor in a short time due to a capillary phenomenon. Further, the peeling liquid is sequentially supplied to the buff rotor by a metering pump or the like, so that the adhesive removing work can be efficiently performed. The shape of the buff rotor preferably has a tip diameter of 10 mmφ or less in order to perform a highly accurate removal operation in a short time. Further, if necessary, the tip shape can be made to be a projection so that the removed portion of the adhesive can be accurately limited. Specific examples of the buff rotor include those obtained by rigidly winding a fibrous material such as paper, glass, wool and cotton. The stripping solution used in the present invention may be any as long as it has a property of decomposing or dissolving an adhesive, and examples thereof include organic solvents such as silene, alcohols and ketones, formic acid, organic acids such as acetic acid, hydrochloric acid and sulfuric acid. Examples thereof include inorganic acids such as the above and alkali compounds such as sodium hydroxide and potassium hydroxide, or a mixture thereof, and these may be dissolved in an appropriate solvent. Further, the adhesive to which the present invention can be applied is not particularly limited as long as it can be decomposed or a solvent by a peeling liquid, and examples thereof include thermoplastic resins such as vinyl acetate and polypropylene, and poly It can be applied to high heat resistant resins such as ether sulfone sun polyimide and polysulfone, and thermosetting resins such as epoxy resin. The repair is completed by connecting a circuit board having the other cleaned circuit surface or a new circuit board to the cleaned circuit surface with an adhesive. At this time, in the case of the hard conductive particles in the adhesive, the conductive particles can break through the residual adhesive layer to enable conductive connection, so that the circuit board separated in the first step can be used as it is. In this case, the peeled circuit board can be used as it is, which is effective for cost reduction.

[0009]

According to the present invention, the buff rotator impregnated with the peeling liquid can dissolve and remove the adhesive in a short time, and the above-mentioned problems can be solved. Further, it has a feature that it is easy to automate the removing work by successively supplying the stripping solution to the buff rotor.

[0010]

EXAMPLES The present invention will be described below by way of examples with reference to FIG. 1, but the present invention is not limited thereto.

Example 1 A Hertbuff rotor (manufactured by Minitor Co., Ltd.) made of wool with a tip diameter of 4 mmφ was attached to a rotating device. On the other hand, FIG.
On a glass substrate 1 as shown in (a), three TAB circuit boards 2 (each having a circuit width of 100 μm and a circuit interval of 100 μm) with a terminal portion of the ITO circuit 5 and a connection width of 30 mm are anisotropic conductive films (epoxy-based, Hitachi Kasei Kogyo Co., Ltd. Anisorum AC-6073 (trade name), thickness 22 μm) was used for conductive connection. FIG. 1B shows a cross section of the connecting portion, showing a state in which the ITO circuit 5 of the glass substrate 1 and the circuit 6 of the TAB substrate 2 are conductively connected by the anisotropic conductive adhesive 3. Next, the central portion of the three TAB substrates was mechanically peeled off. FIG. 1C shows this state, in which the cured adhesive 3 is fixed on the ITO circuit, and this was subjected to the test of the method according to the present invention. Then, FIG.
As shown in (e), the buff rotator 4 impregnated with toluene, which is a dissolving solvent, is placed on the adhesive to be removed, and at the same time, the adhesive is sequentially removed, and another buff rotator impregnated with methanol is used. After the wiping finish, as shown in FIG. 1F, the adhesive in the desired portion was completely removed to expose the ITO circuit 5. Since the surface of the ITO circuit 5 uses a soft belt buff, the circuit is not damaged and is in a clean state. The time required up to this point was 45 seconds, and the removing operation was completed in 1/3 of the time required for the conventional adhesive removing method. After this removing method was performed, a new TAB circuit was reconnected by an Anisorum AC-6073 to the ITO circuit on the glass substrate from which the adhesive was removed as shown in FIG. The connection resistance of each TAB circuit after reconnection was measured, but the connection resistance of the reconnected TAB circuit section, the connection resistance value of the TAB circuit adjacent to this, and the connection before the adhesive was removed The difference from the resistance value is within ± 0.5Ω,
No increase in resistance was observed.

Example 2 The removal method was carried out while successively supplying the solvent in Example 1 to the side of the buff rotor by a metering pump. The required time was 35 seconds, and the work for removing the adhesive could be further shortened. Even in this case, no increase in connection resistance was observed.

Comparative Example 1 For removing the adhesive in the above example, a cotton swab impregnated with toluene was rubbed with the adhesive to dissolve the adhesive, and the dissolved adhesive was appropriately removed with a Teflon spa tape to remove methanol. Was wiped with a cotton swab impregnated with. The time required for this was about 3 minutes. As a result, the difference between the connection resistance value of the TAB circuit for reconnection and the connection resistance value before the removal of the adhesive was within ± 0.5Ω, and no increase in the resistance value was observed. In addition, the resistance value increased from the end portion adjacent to the TAB circuit, and the circuits in which the resistance value increased by 100Ω or more were 28 places in total of the two TAB circuits.

[0014]

As described above in detail, according to the present invention, the adhesive can be removed in a short time and with high accuracy, and the reliability of reconnection can be greatly improved. .

[Brief description of drawings]

1A to 1G are schematic views showing an embodiment of the method of the present invention in the order of steps.

[Explanation of symbols]

 1 Glass Substrate 2 TAB Substrate 3 Adhesive 4 Buff Rotor 5 ITO Circuit 6 TAB Substrate

Claims (2)

[Claims] 1. A method for repairing a defective conduction portion of a circuit connecting portion in which a large number of opposing circuits are conductively connected via an adhesive, comprising the following steps (1) to (4): A characteristic method for repairing circuit connections. (1) Peel off the mutual joints of the connection parts that require repair,
A step of placing a buff rotor having a predetermined shape on the adhesive surface remaining on at least one circuit surface. (2) A step of temporarily contacting the peeling liquid with the adhesive by impregnating the buffing rotor with the peeling liquid. (3) A step of cleaning the circuit surface in contact with the buff rotor impregnated with the stripping solution. (4) A step of reconnecting the circuit surface of the other circuit board to the cleaned circuit surface with an adhesive. 2. The method for repairing a circuit connecting portion according to claim 1, wherein the stripping solution can be successively supplied to the buff rotor.