JPH0437147A - Mounting of semiconductor chip - Google Patents

Abstract

PURPOSE:To certainly realize connection between a glass substrate and a semiconductor chip without conducting high temperature heat treatment by supplying photo-setting conductive type resin to an electrode pad on which a recessed area is formed, placing conductive balls thereon, stacking electrodes of a semiconductor chip of such conductive balls and executing the positioning by moving the conductive balls. CONSTITUTION:A recessed area 12a is formed on an electrode 12 of a semiconductor chip 11, an upper layer 15 is formed on a wiring 16 of a glass substrate, the wiring 16 is exposed by selectively removing the upper layer 15 and an electrode pad 20 forming the recessed area is provided, photo-setting conductive resin 14 is supplied to the electrode pad 20, conductive balls 13 are placed on the photo-setting conductive resin 14 and the electrode 12 of semiconductor chip 11 is stacked on the conductive balls 13 through face-down of the semiconductor chip 11. The conductive balls 13 are rotated and moved within the electrode pad 20 to paste the entire part of the conductive balls 13 with the photo-setting conductive resin 14 and conduct the positioning. After the positioning, a load is applied from the upper direction of semiconductor chip 11 for standstill. The electrode pad 20 is irradiated with the light 19. Thereby the photo-setting conductive resin 14 is hardened to establish electrical connection.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a method for mounting a semiconductor chip on a glass substrate by face-down bonding without bumping the semiconductor chip.

(Prior art) Conventionally, as a technology in this field, for example, Japanese Patent Application Laid-open No. 5
There were those described in No. 9-195837 and JP-A-61-94330.

FIG. 3 shows an example of face-down bonding mounting of a semiconductor chip on such a conventional glass substrate, that is,
Figure 3 (a) shows a solder bump connection method, Figure 3 (b) a gold bump connection method, and Figure 3 (c) a method in which gold bumps (or solder bumps) are connected with thermosetting conductive resin. be.

Next, each connection method will be explained below with reference to FIGS. 3(a) to 3(c).

First, as shown in FIG. 3(a), the solder bump connection method uses solder (Pb-Sn) formed on the electrodes of the semiconductor chip 1.
) After temporarily fixing the bump 2 to a metal film 5 with good solder wettability with a solder dam 8 on a metal film 6 formed on a glass substrate 9 using flux, etc., heat the bump 2 to a temperature of about 180 to 350°C using infrared reflow or a hot plate. The solder is melted and connected at high temperatures.

In the gold bump connection method shown in FIG. 3(b), the gold bumps 3 formed on the electrodes of the semiconductor chip 1 are placed on the metal film 6 of the wiring of the glass substrate 9 in alignment with the Sn plating film 7. The gold bump 3 and the Sn plating film 7 are connected by an Au-3nn eutectic stand at a high temperature of about 450°C.

The method of connecting the gold bumps (or solder bumps) shown in FIG. 3(c) with a thermosetting conductive resin is to apply the thermosetting conductive resin 4 to the wiring 6 of the glass substrate 9 using the dispenser method or screen printing. The semiconductor chip 1 is selectively supplied by the method.
A method was used in which a gold bump (or solder bump) 3 was pressed thereon, and the conductive resin was cured at a temperature of about 150° C. to make the connection.

(Problem R to be solved by the invention) However, in the semiconductor chip mounting method described above, (1) connection failures such as disconnections occur due to the influence of variations in bump shapes;

(2) In the face-down bonding method using solder bumps, since the solder is melted to make the connection, it cannot be bonded to electrode pads on a board with poor solder wettability, and it cannot be bonded to electrode pads that can be soldered. , 180-35
It is necessary to heat it to a high temperature of about 0°C.

(3) In the face-down bonding method using gold bumps, the connection is made by eutectic gold, so the electrode band on the substrate must be plated with Sn.
In order to perform -3n eutectic, high temperature heating of about 450°C is required.

(4) When bonding is performed using the solder bump method or the gold bump method, heating is always required, so that the wiring on the board is subjected to thermal stress during manufacturing, making it easy to cause disconnection.

(5) In a high-density semiconductor chip with a large number of bumps, that is, a large number of connection terminals, and narrow intervals between the terminals, it is difficult to obtain good bonding alignment accuracy.

(6) In manufacturing semiconductor chips, it is difficult to form bumps and the number of steps increases.

There were some problems.

In order to eliminate the above-mentioned problems, the present invention connects a bumpless semiconductor chip to an electrode pad on a substrate using a conductive ball and a photocurable conductive resin, and aligns the conductive ball by moving the conductive ball. Therefore, it is an object of the present invention to provide a semiconductor chip mounting method that can be reliably carried out without high-temperature heating.

(Means for Solving the Problems) The present invention provides a semiconductor chip mounting method for face-down bonding a semiconductor chip onto a glass substrate.
A recess is formed in the electrode of the semiconductor chip 7, an upper layer is formed on the wiring of the glass substrate, the upper layer is selectively removed to expose the wiring, and the electrode pad in which the recess is formed is formed. and supplying a photocurable conductive resin to the electrode band,
Place a conductive ball on the photocurable conductive resin, place the semiconductor chip face down, overlap the electrode of the semiconductor chip on the conductive ball, and rotate and move the conductive ball within the electrode pad. Then, the entire conductive sphere is filled with the photocurable conductive resin and aligned, and after the alignment, a load is applied from the top surface of the semiconductor chip to make it stand still, and the electrode pads are irradiated with light. , the photocurable conductive resin is cured to establish an electrical connection.

(Function) According to the present invention, as described above, an electrode having a recess is formed on the semiconductor chip, and a metal film is formed on the transparent electrode film as a base on the glass substrate side, For only the electrode pad portion, the metal film is removed to form an electrode pad having a concave recess so that the transparent electrode film is exposed, a photocurable conductive resin is supplied into this electrode pad, and further, the electrode pad is A conductive layer on the order of 5 μm to several tens of μm is applied to the electrode pad on the photocurable conductive resin, and the conductive layer can freely rotate and move within the electrode pad when force is applied. A conductive pad is sandwiched between the electrode of the semiconductor chip and the electrode pad of the substrate, and the conductive pad is pressed from the chip side and rolled within the electrode pad for fine alignment, and then light is emitted from the back side of the substrate. The photocurable conductive resin is cured by irradiation, and the glass substrate and the semiconductor chip are connected. Therefore, the glass substrate and the semiconductor chip can be reliably connected without performing high-temperature heating.

(Example) Hereinafter, an example of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a cross-sectional view of a mounting process of a semiconductor chip on a glass substrate showing an embodiment of the present invention, and FIG. 2 is an enlarged cross-sectional view showing the main parts thereof.

First, as shown in FIG. 1(a), a transparent electrode film 16, such as an ITO film or a NESA film, is formed as a wiring pattern on a glass substrate 17 by vapor deposition. one or more metal films 15, for example Cu-Cr, by a method or a thick film printing method.

Au-Cr etc. are formed. Note that the metal film 15 of the electrode pad 20 on the glass substrate 17 is removed to form a concave depression.

Next, as shown in FIG. 1(b), while adjusting the viscosity of the photocurable conductive resin 14, the electrode pads in which the concave recesses are formed are selectively applied using a dispenser method or a screen printing method. Supply 20.

Furthermore, one conductive layer 13 per electrode pad is applied to the electrode pad 20 to which the photocurable conductive resin 14 has been supplied.
Generally, spherical metal balls such as Ni, solder, or Pb are used, but balls made of plastic such as polyethylene (PE) or polymethyl methacrylate (=PMMA) plated with Au or Ni are also used. . The conductivity method 1
3 is selected from an optimal size of 5 μm to several tens of μm depending on the electrode size of the semiconductor chip or the electrode pitch.

Note that in the above conductive method, one electrode pad is provided for each electrode pad, but a plurality of electrode pads may be provided as long as it does not cause any trouble in alignment.

On the other hand, the electrodes 12 of the semiconductor chip 11 will be explained in detail based on FIG. 2.

As shown in FIG. 2(a), the electrode 12 is a metal electrode formed in the circuit of the semiconductor chip 11 by a vapor deposition method or a plating method, and has a hemispherical recess 12a. This can be formed by under-etching in the etching process of the normal bump manufacturing process. This electrode 12 is formed and made face down.

As described above, the glass substrate 17 - conductive method 13 - semiconductor chip 11 are superimposed, and the electrode pads 2 of the glass substrate 17 are stacked together.
0 and the semiconductor chip 11 using the conductive method 13 to conduct the inside of the electrode pad 20 in which a concave depression is formed.
3 while rotating and moving the conductive ball 13.
After completing the 0 positioning so that the entire surface is coated with photocurable conductive tMIii, light 1 is applied from the back side of the board while applying pressure.
9. For example, by irradiating ultraviolet rays (irradiation from the side can also be used), the photocurable conductive resin 14 is cured, as shown in FIG. was fixed and connected to the board.

FIG. 4 is a sectional view of the main part of mounting a semiconductor chip on a glass substrate, showing another embodiment of the present invention.

In this embodiment, the semiconductor chip 11 having the electrode 18 in which the concave depression 18a is formed is face-down in the same manner as described above.

Furthermore, because the photocurable conductive resin was not applied properly to the conductive method at the end, poor connection between the conductive method and the semiconductor chip may occur. It is desirable to fix the semiconductor chip by sealing it with an insulating resin.

Furthermore, the present invention is not limited to the above embodiments,
Various modifications are possible based on the spirit of the present invention, and these are not excluded from the scope of the present invention.

(Effects of the Invention) As described above in detail, according to the present invention, a conductive ball and a photocurable conductive resin are used to connect an electrode pad on a glass substrate and a semiconductor chip, so bump connection is possible. The number of electrode formation steps for semiconductor chips is reduced, and variations in connection height can be adjusted using resin, so there are no connection failures.Furthermore, since there is no need for heating during connection, there is no disconnection due to thermal stress.

Further, by providing depressions in the electrodes of the semiconductor chip and the electrode pads of the substrate, and allowing the conductive sphere to move freely within the depressions, alignment can be easily performed.

[Brief explanation of the drawing]

Fig. 1 is a sectional view of the mounting process of a semiconductor chip on a glass substrate showing an embodiment of the present invention, Fig. 2 is an enlarged sectional view showing the main parts thereof, and Fig. 3 is a face of a semiconductor chip on a conventional glass substrate. Diagram showing an example of down bonding implementation, No. 4
The figure is a sectional view of the main part of mounting a semiconductor chip on a glass substrate, showing another embodiment of the present invention. DESCRIPTION OF SYMBOLS 11... Semiconductor chip, 12.18... Electrode of semiconductor chip, 12a... Hemispherical depression, 13... Conductive sphere, 14... Photocurable conductive resin, 15... Metal film, 16... Transparent electrode film, 17... Glass substrate, 1
8a--Concave depression, 19--Light (ultraviolet), 20
...Electrode pad. Patent Applicant Oki Electric Industry Co., Ltd. Agent Patent Attorney Mamoru Shimizu (1 other person) Figure 3

Claims (1)

[Claims] In a semiconductor chip mounting method in which a semiconductor chip is face-down bonded onto a glass substrate, (a) a recess is formed in the electrode of the semiconductor chip, and (b) an upper layer is formed on the wiring of the glass substrate. (c) selectively removing the upper layer to expose the wiring and providing an electrode pad with a recess formed therein; (d) supplying a photocurable conductive resin to the electrode pad; , (e) place a conductive ball on the photocurable conductive resin, (f) place the semiconductor chip face down, overlap the electrodes of the semiconductor chip on the conductive ball, and place the conductive ball on the conductive resin. Rotate and move within the electrode pad to fill the entire conductive sphere with the photocurable conductive resin and align the conductive sphere; (g) After the alignment, apply a load from the top surface of the semiconductor chip to make it stand still; A method for mounting a semiconductor chip, comprising: irradiating the electrode pad with light to cure the photocurable conductive resin to establish an electrical connection.