JPH09111192A - Method for peeling ic chip and peeling jig used for the method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To facilitate the peeling of IC chips from a substrate without impairing the IC chips and the circuit on the substrate by using a specified method. SOLUTION: A method for peeling off a pair of IC chips connected to a substrate with an adhesive from the substrate, wherein a peeling jig having a tapered sharp edge is inserted into the connecting part between the substrate and the IC chips to apply a shear stress to the IC chips on the substrate to thereby peel off the IC chips from the substrate. More specifically, the substrate is placed and fixed on a heating source heated to 150-250 deg.C, and after heating for a prescribed time, a shear stress is applied to the connecting part on the lower side of the IC chip from one direction with the tip of the peeling jig. The angle of inclination of the jig is required to be less than 45 deg., preferably less than 10 deg..

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an IC chip peeling method for peeling an IC chip connected to a substrate with an adhesive from the substrate and an IC chip peeling jig used in the method.

[0002]

2. Description of the Related Art Conventionally, as a connection method in the case where connection terminals are formed relatively finely with respect to each other, such as connection of integrated circuits to a wiring board, connection between display elements and a wiring board, etc. A method in which a conductive material is dispersed in an insulating adhesive film, and an anisotropic conductive film having anisotropic conductivity is used to bond and fix the opposing electrodes in contact with each other, or a conductive adhesive is printed on the connection terminals. Various connection methods are used, such as arranging by transfer or transfer, connecting terminals facing each other, and pouring and fixing an insulating adhesive between the integrated circuit and the wiring board.

By the way, when the electric connection is defective in the connection by the adhesive or the IC chip has a defect after the connection, it is necessary to peel off and replace the IC chip. In this case, from room temperature to 400 ° C. A method of heating the IC chip to peel the IC chip from the substrate is generally used.

For example, as shown in FIG.
After the connection body in which the C chip 2 is connected using the adhesive 3 is placed and fixed on the heating source 4, the IC is removed by the peeling jig 5.
There is a method of covering the upper surface and the side surface of the chip 2 and rotating the peeling jig 5 in the direction of the arrow in the drawing to apply shear stress to the IC chip to peel it.

Also, as shown in FIG. 4, the IC is viewed from one direction.
By pressing the peeling jig 5 against the side surface of the chip 2, the IC chip 2
There is also a method in which a shear stress is applied to the IC chip 2 to peel it off.

[0006]

However, in the peeling method shown in FIG. 3, for example, COG (Chip on bo) for connecting a bare IC chip for driving to a liquid crystal panel is used.
ard), the display area is large and the panel itself is small, and the area for connecting the IC chip is small.
When the distance between the C chips and the glass substrate of the liquid crystal panel is small, the IC chips cannot be fixed by the conventional jig, and when thermosetting resin or photocurable resin is used as the adhesive, The adhesive strength of the connection is so high that it cannot be peeled off.

Further, in the method of peeling by using a jig configured to apply a shear stress to the side surface of the IC chip from one direction shown in FIG. 4, there is a problem that the IC chip is broken when the bonding strength of the connection portion is high. It was

The present invention has been made in view of the above circumstances, and an IC chip peeling method and a method for peeling an IC chip from a substrate without damaging the IC chip and the substrate circuit. It is intended to provide a peeling jig for use in.

[0009]

In order to achieve the above object, the present invention provides a method of peeling a bare IC chip, which is connected to a substrate by using an adhesive, from the substrate in a tapered shape. A peeling jig having a sharp tip is inserted into the connecting portion between the substrate and the IC chip, and I
It is characterized in that shear stress is applied to the C chip to separate it from the substrate.

Here, the electrodes of the IC chip are electrically connected to the circuit electrodes formed on the substrate by an anisotropic conductive adhesive, and at the same time, the lower surface and side surfaces of the IC chip are fixed.

Further, the substrate to which the IC chip is connected and fixed is placed on the heating block and heated from the lower part of the substrate to concentrate the stress on the connection portion on the lower surface of the IC chip, so that the tip portion is inclined so as to be thin. The peeling jig having a sharp tip portion is used to apply shearing stress to the connecting portion, thereby peeling.

The peeling jig must have an inclination angle of 45 ° or less, preferably 10 ° or less.

Here, as the substrate, for example, a glass substrate, a ceramic substrate, a film substrate made of polyimide or the like, a glass epoxy substrate, or the like, ITO, Al,
A thin film electrode of Ni, Au or the like, an electrode of a conductive paste containing Cu foil or Ag, Ni or the like is provided, and a surface layer of Sn, Au, solder or the like may be formed on the surface of these electrodes. it can.

The IC chip adhered on the substrate has a large number of electrodes, and the electrodes include aluminum, gold,
Chromium, copper, solder, etc. are used.

A surface layer of Sn, Au, solder or the like can be formed on the surface of these electrodes.

Further, as an adhesive for adhering the both, an epoxy type resin, an acrylic type resin, a silicone type resin or the like can be applied, and a reactive resin which reacts with heat or light is preferable.

Conductive particles may be added to these adhesives.

Next, in order to peel off the IC chip, the substrate is placed and fixed on a heating source heated to 150 to 250 ° C., and after heating for a predetermined time, the tip of the peeling jig I
Shear stress is applied to the connection portion on the lower surface of the C chip.

Since the adhesive is heated at a high temperature, the shear adhesive strength is reduced, and the peeling jig can concentrate the stress on the connecting portion, so that it can be easily peeled off.

As a heating means, an electric heater, high-frequency heating, infrared irradiation, laser beam irradiation, hot air irradiation, etc. can be applied, and not only from the substrate side, but also a constitution in which a heating part is provided on the peeling jig can be adopted. it can.

As described above, the peeling jig having the taper portion which is inclined so that the tip portion becomes thin is used, and the shearing stress can be concentrated on the bonding portion. Therefore, the IC chip can be easily peeled off without damaging the IC chip and the substrate circuit electrode.

[0022]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of an IC chip peeling method and a peeling jig used in the method according to the present invention will be described below in detail with reference to the accompanying drawings.

FIG. 1 is a schematic sectional view for explaining the method of the present invention,
FIG. 2 is an outline view of a peeling jig used in the method of the present invention.

In FIG. 1, the electrodes 11 of the IC chip 10 are shown.
Is electrically connected to the circuit electrode 13 formed on the substrate 12 by the anisotropic conductive adhesive 14, and at the same time, the lower surface and the side surface of the IC chip 10 are fixed.

The IC chip 10 on one glass substrate 12 of the liquid crystal panel 15 on which the ITO circuit electrode 13 is formed.
(Outer diameter 4 × 8 mm, thickness 0.5 mm, electrode height 20 μ
The case where the method of the present invention is applied to a connection body having m and the number of electrodes 200) is shown.

As the anisotropic conductive adhesive 14, a film-like anisotropic conductive film in which conductive particles are dispersed in an adhesive containing an epoxy resin as a main component is used.
The heating and pressing were performed under the conditions of gf / chip and 20 seconds.

The above-mentioned connecting body is placed on a heater (heating source) 16 at 150 to 250 ° C., the glass substrate 12 is fixed, and 1
After leaving for a minute, the peeling jig 17 (tip portion 0.1 mm, inclination angle 2 shown in FIG. 2 is formed to be thin.
(0 °) was aligned with the connection portion under the IC chip 10 and one end of the peeling jig 17 was pressed with a push-pull gauge to peel the IC chip 10 and measure the peeling force.

At 150 to 250 ° C., peeling was possible with a load of 10 to 5 kg.

In some cases, the adhesive 14 may remain on the glass substrate 12, and the IC chip 10 and the ITO circuit electrode 13 which have been peeled off by applying an epoxy stripping solution and wiping off with a cotton swab after 1 hour and the ITO circuit electrode 13 are found to be broken. There wasn't.

Further, in the conventional method shown in FIG. 3, it was not possible to fix the IC chip by applying a stress because the space between the chip and the substrate glass was narrow (1 mm or less).

Further, according to the conventional method shown in FIG.
The chip was broken under a load of g, and a part of the chip remained on the substrate.

[0032]

As described above, in the method of peeling an IC chip according to the present invention, a peeling jig having a sharp taper tip is inserted laterally into the connecting portion between the IC chip and the substrate. Shear stress is applied to the connection part, and the shear adhesive force is reduced by heating to perform peeling.
There is an effect that the IC chip can be easily peeled off without destroying the chip and the substrate circuit electrode, and the workability of peeling the IC chip can be remarkably improved.

[Brief description of the drawings]

FIG. 1 is a schematic sectional view showing a method of the present invention.

FIG. 2 is an outline view of a peeling jig used in the method of the present invention.

FIG. 3 is a schematic sectional view showing a conventional IC chip peeling method.

FIG. 4 is a schematic cross-sectional view showing a conventional IC chip peeling method.

[Explanation of symbols]

 10 IC Chip 11 Electrode 12 Glass Substrate 13 Circuit Electrode 14 Adhesive 15 Liquid Crystal Panel 16 Heat Source 17 Peeling Jig

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Osamu Watanabe 1500 Ogawa, Shimodate, Ibaraki Pref. Within Shimodate Research Laboratory, Hitachi Chemical Co., Ltd. (72) Kenzo Takemura 1500, Ogawa, Shimodate, Ibaraki Hitachi Chemical Co., Ltd. Shimodate Research Center (72) Inventor Kyokuhisa Ota 1500 Ogawa, Shimodate City, Ibaraki Prefecture Hitachi Chemical Co., Ltd. Shimodate Research Center

Claims (5)

[Claims] 1. A peeling jig for peeling a bare IC chip connected to a substrate using an adhesive from the substrate, wherein a peeling jig having a tapered sharp tip is used for the substrate and the IC chip. The method of peeling an IC chip, comprising: inserting the IC chip on a substrate and applying shearing stress to the IC chip to peel the substrate from the substrate. 2. The method of peeling an IC chip according to claim 1, wherein shearing stress is applied while the IC chip is heated to peel the IC chip from the substrate. 3. The IC chip peeling method according to claim 1, wherein the IC chip is peeled off while measuring the shear stress applied to the IC chip from the peeling jig. 4. A jig for peeling an IC chip, which peels a bare IC chip connected to a substrate with an adhesive from the substrate, in order to concentrate stress on a connecting portion between the IC chip and the substrate. A jig for peeling an IC chip, wherein the tip is set to a sharp taper shape. 5. The jig for peeling an IC chip according to claim 4, wherein the thickness of the tip of the peeling jig is thinner than the thickness of the IC chip.