JPH03104232A - Transferring method for bump electrode - Google Patents

Abstract

PURPOSE:To eliminate damage to a second substrate accompanied by the transfer of a bump electrode by pressing a first substrate and the second substrate, superposed so that a metal terminal and a transferring bump electrode face each other, in the facing direction and press-contacting the transferring bump electrode, got into a resin layer by the pressing, with the metal terminal and then removing the second substrate. CONSTITUTION:An ultraviolet hardening resin layer 5 is deposited on the surface of a first substrate 1 on which a metal terminal 2 for bump electrode deposition is formed, and a transferring bump electrode 4 is formed on the surface of a second substrate which has low close contacting property against the bump electrode material. Then, the first substrate 1 and the second substrate 3, superposed so that the metal terminal 2 and the transferring bump electrode 4 face each other, are pressed in the facing direction and the transferring bump electrode 4, got into a resin layer 5 by the pressing, is press-contacted with the metal terminal 2 and then the second substrate 3 is removed. Thus, lower temperature heating than in the prior art transfer and lower pressure can be used. Accordingly, damage to the second substrate, i.e., a chip, etc., to which the bump electrode is transferred, can be avoided during the transfer of the bump electrode.

Description

[Detailed Description of the Invention] [Summary] Regarding a new method for transferring bump electrodes formed on a second substrate to a first substrate, the present invention aims to eliminate damage to the second substrate due to transfer of the bump electrodes. A layer of an ultraviolet curable resin, a thermoplastic resin, or a thermosetting resin is applied to the surface of the first substrate on which the metal terminal for bump electrodes is formed, and a second layer having weak adhesion to the bump electrode material is applied. forming a transfer bump electrode on the surface of the substrate,
The metal terminal and the transfer bump electrode are pressed against the first substrate and the second substrate, which are stacked so as to face each other, and the transfer bump electrode penetrates into the resin layer by the pressing. The second substrate is removed after being crimped onto the metal terminal.

[Industrial application field]

The present invention relates to a bump electrode transfer method for forming bump electrodes onto an electronic circuit chip, an insulating substrate, etc. using a transfer means.

Recent liquid crystal display panels are required to be thinner, lighter, and cheaper in addition to larger display screens. Therefore, the chip mounting structure of the panel drive circuit components mounted on the panel is a TAB (tape automated boning) structure that uses an outer lead bonding device.
The COG (chip on glass) method is about to replace the COG (chip on glass) method, which uses bump electrodes made of gold or the like.

[Conventional technology]

FIG. 5 is an explanatory diagram of a method of transferring bump electrodes according to the prior art, and FIG. 6 is an explanatory diagram of a method of mounting the chip shown in FIG. 5.

In FIG. 5(A), on the upper surface of an electronic circuit chip (first substrate) 1 on which bump electrodes are to be formed, metal terminals 2 for bump electrodes, which are metallized with gold, are formed at predetermined portions thereof.

In FIG. 5 (0), gold bump electrodes 4 facing the terminals 2 are formed on the surface of the transfer glass substrate (second substrate) 3 which has weak adhesion to the bump electrode material.

In FIG. 5(c), in order to stack the glass substrate 3 on top of the chip l and form 100 bump electrodes 4 with an appropriate pressing force FO of, for example, 50 μffiI1 in an atmosphere heated to about 400° C., approximately 3 kg is required. When a pressing force F0 of 2 is applied, the bump electrode 4 is bonded to the terminal 2 by diffusion or eutectic.

Next, after cooling to room temperature, the glass substrate 3 is removed, and the bump electrodes 4 peeled off from the glass substrate 3 are transferred and formed on the terminals 2 of the chip 1, as shown in FIG. 5(2).

In FIG. 6(A), a resin layer 5, for example, an ultraviolet curable resin (UV
A layer 5 (resin) is applied.

Next, as shown in FIG. 6 (+1), a light-transmitting insulating substrate (glass substrate) 7 having a terminal 6 formed on its upper surface to which the bump electrode 4 is bonded is placed on a table 10 provided with a hole 9 through which ultraviolet rays 8 can pass.
Fixed to. The table IO can be moved in the X-Y direction and rotated (θ).

The chip 1 whose positional relationship with the substrate 7 has been corrected is the bump electrode 4
is directed downward, and is pressed against the substrate 7 with an appropriate pressing force F by a vertically movable heater plate 11, and the resin 5 is irradiated with ultraviolet rays 8 through the substrate 7.

As a result, the bump electrode 4 is bonded to the terminal 6 as shown in FIG. 6(C), and the periphery of the bonded bump electrode 4 is hardened with a hardened UVI layer 5.

[Problem to be solved by the invention]

As described above, in the conventional bump electrode transfer method, when transferring the bump electrode 4, pressure is applied at high temperature.

Therefore, cracks may occur in the chip l.
Significantly, the cracks cause the chip 1 to break. It is extremely difficult to replace such a damaged chip 1, and it may be necessary to discard it together with the board 7.

An object of the present invention is to eliminate damage to the chip during transfer of bump electrodes.

[Means to solve the problem]

According to FIG. 1 showing an embodiment of the present invention, a layer 5 of an ultraviolet curable resin is applied to the surface of a first substrate 1 on which a metal terminal 2 for applying bump electrodes is formed, and a layer 5 of an ultraviolet curable resin is applied to the bump electrode material. On the other hand, the transfer bump electrode 4 is formed on the surface of the second group vi3 which has weak adhesion, and the first substrate l is stacked so that the metal terminal 2 and the transfer bump electrode 4 face each other.
and the second substrate 3 in opposing directions, and the transfer bump electrodes 4 that have protruded into the resin layer 5 by the pressing are crimped onto the metal terminals 2, and then the second substrate 3 is removed. This is a method of transferring bump electrodes.

[Effect]

As explained above, the bump electrode transfer method according to the present invention does not require heating or requires heating at a lower temperature than the conventional transfer method when transferring the bump electrode from the second substrate to the first substrate. In addition, the pressurizing force can be less than that of the conventional method.

Therefore, the second substrate such as a chip onto which the bump electrodes are transferred is not damaged during the transfer of the bump electrodes.

〔Example〕

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is an explanatory diagram of the main steps of a bump electrode transfer method according to an embodiment of the method of the present invention, FIG. 2 is an explanatory diagram of the chip mounting method shown in FIG. 1, and FIG. 3 is an explanatory diagram of another method of the present invention. FIG. 4 is an explanatory diagram of the main steps of the bump electrode transfer method according to the embodiment, and FIG. 4 is an explanatory diagram of the chip mounting method shown in FIG. 3. In FIGS. 1 to 4, the same reference numerals are used for parts common to those in the previous figures.

In FIG. 1(a), on the upper surface of an electronic circuit chip (first substrate) l on which bump electrodes are to be formed, metal terminals 2 for attaching bump electrodes metallized with gold are formed on predetermined portions of the electronic circuit chip (first substrate) l on which bump electrodes are to be formed. A resin (UV resin) layer 5 is applied.

In FIG. 1(0), on the surface of the transfer glass substrate (second substrate) 3, which has weak adhesion to the bump electrode material,
A gold bump electrode 4 facing the terminal 2 is formed.

In FIG. 1(c), a glass substrate 3 with bump electrodes 4 facing downward is placed on top of the chip l, and
Appropriate pressing force F', for example 50°C,
To form 100 bump electrodes 4 of μ- +1, a pressing force F of approximately 1 kg is required! Press it with

Then, as shown in FIG. 1 (2), each bump electrode 4 pushed into the resin layer 5 is formed into a chip by the pressure force between its tip and the terminal 2 and the adhesion force between the bump electrode 4 and the resin layer 5. It comes to be joined to l.

Therefore, when the glass substrate 3 is removed, the bump electrodes 4 are peeled off from the glass substrate 3 and remain embedded in the resin layer 5 on the chip 1, as shown in FIG. In FIG. 2(a), a translucent insulating substrate (glass substrate vi) 7 on which a bump electrode connection terminal 6 is formed is fixed to a table 10 provided with a hole 9 for transmitting ultraviolet rays 8. The chip 1, whose positional relationship with the temporary 7 is corrected, has the bump electrodes 4 facing downward, is pressed against the substrate 7 with an appropriate pressing force F by the vertically movable heater plate 11, and is pressed against the resin layer 5 through the substrate 7. is irradiated with ultraviolet rays 8.

As a result, the bump electrodes 4 are bonded to the terminals 6 as shown in FIG. .

In FIG. 3 (A), on the upper surface of the electronic circuit chip (first substrate) ■ on which the bump electrodes are to be formed, metal terminals 2 for bump electrodes are formed with gold metallized on the upper surface of the electronic circuit chip (first substrate) ■, which is made of thermoplastic resin. Alternatively, a layer 12 of thermosetting resin is applied.

In FIG. 3(0), on the surface of the transfer glass substrate (second substrate) 3, which has weak adhesion to the bump electrode material,
The gold bump electrode 4 facing the terminal 2 is shaped.

In FIG. 3(c), the glass substrate 3 with the bump electrodes 4 facing downward is placed on top of the chip l, and
Appropriate pressing force F when heated to around °C! , for example S
In order to form 100 bump electrodes 4 of Oμ-I1, pressing is performed with a pressing force F2 of about 1 kg.

Then, as shown in FIG. 3(2), each bump electrode 4 pushed into the resin layer 12 is chipped due to the pressure force between its tip and the terminal 2 and the adhesion force between the bump electrode 4 and the resin layer 12. 1.

Therefore, when the glass substrate 3 is removed, the bump electrodes 4 are separated from the glass substrate 3 and are left on the chip l embedded in the resin layer l2, as shown in FIG. 3(N). .

In FIG. 4(A), a translucent insulating substrate (glass substrate) 7 having bump electrode connection terminals 6 formed on its upper surface is fixed to the upper surface of a table 13. The chip 1, whose positional relationship with the substrate 7 has been corrected, has the bump electrode 4 facing downward, and is pressed against the base 7 with an appropriate pressing force F+ by the vertically movable heater plate H1.

As a result, the bump electrode 4 is joined to the terminal 6 as shown in FIG. 4 (t!), and the joined bump electrode 4 is connected to the bump electrode 4.
At the same time, the chip 1 is solidified with a heated and hardened resin layer l2, and the mounting of the chip 1 is completed.

Note that although the above embodiments relate to liquid crystal display panels, the present invention can be widely used in semiconductor devices and the like.

〔Effect of the invention〕

As explained above, according to the method of the present invention, when transferring bump electrodes from the second substrate to the first substrate, there is no need to heat or it is only necessary to heat the bump electrodes to a lower temperature than in the conventional transfer method. Since the second substrate, such as a chip, to which the bump electrodes are to be transferred is not damaged during the transfer of the bump electrodes, the second substrate, such as a chip, is not damaged during the transfer of the bump electrodes.

[Brief explanation of drawings]

Fig. 1 is an explanatory diagram of the main steps in one embodiment of the method of the present invention, Fig. 2 is an explanatory diagram of the chip mounting method shown in Fig. 1, and Fig. 3 is an explanatory diagram of the main steps in another embodiment of the method of the present invention. FIG. 4 is an explanatory diagram of the method for mounting the chip shown in FIG. 3. FIG. 5 is an explanatory diagram of the method of transferring bump electrodes according to the prior art. This is an explanatory diagram of the implementation method. In the figure, 1 is a chip (first substrate), 2 is a metal terminal to which a bump electrode is attached, 3 is a glass substrate (second substrate), 4 is a bump electrode, 5 is an ultraviolet curable resin layer, and 12 is a heat Indicates a plastic or thermosetting resin layer. Theory of the main electrical process of 11, 2, 1, and 1 of 6 uninvented spears a
f.
Figure omota aft million! 112 B. The Shoki of the Master of Japanese Crafts, θ Month Figure No. 3 (Ino (Rono 3rd entry 1; Showed to, 7'/) The meaning of the actual ceremony of the offering ceremony Leap (c) (22 The fruit of 1,000 t7 shown in the 5th leap ij 60 theory af 4 figure b
ridge

Claims (1)

[Claims] A layer (5, 12) of an ultraviolet curable resin, a thermoplastic resin, or a thermosetting resin is applied to the surface of the first substrate (1) on which the metal terminal (2) for attaching the bump electrode is formed. a second substrate (3) to which the bump electrode material is adhered and has weak adhesion to the bump electrode material;
A transfer bump electrode (4) is formed on the surface of the first substrate (1) and the second substrate, which are stacked so that the metal terminal (2) and the transfer bump electrode (4) face each other. The substrate (3) is pressed in the opposite direction, and the pressing causes the resin layer (
5, 12) A method for transferring a bump electrode, characterized in that the second substrate (3) is removed after the transfer bump electrode (4) inserted into the metal terminal (2) is crimped onto the metal terminal (2).