JP2002368046A - Method for mounting chip - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for mounting a chip in which stabilized electrical connection can be realized by ensuring adhesion between the conductive part of a semiconductor substrate and a bump part. SOLUTION: A method for mounting a chip comprising a step for placing a paste at a bump part 3 provided on a chip 1, and a step for disposing the chip 1 oppositely to a semiconductor substrate 6 at a specified position thereof while aligning the bump part 3 and a conductive part 5 provided on the semiconductor substrate 6 and then connecting or mounting the chip 1 is further provided with a step for roughening the surface at the bump part 3 of the chip 1 and placing the paste at the bump part 3.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a chip mounting method for fixing a chip on a semiconductor substrate provided with a predetermined conductive pattern and electrically connecting the chip to the semiconductor substrate.

[0002]

2. Description of the Related Art As a conventional chip mounting method, for example, as shown in FIG. 3, a chip 1 having a bump portion 3 such as a gold stud bump formed on an electrode pad 2 and a conductive portion 5 such as a conductive pattern are provided. A flip chip mounting method for electrically connecting the chip 1 and the semiconductor substrate 6 to the semiconductor substrate 6 having the bump portion 3 and the conductive portion 5 via a paste 4 such as a conductive adhesive. Can be

[0003] The following describes the chip mounting method. First, as shown in FIGS. 3A and 3B, the transfer stage 1
The paste 4 provided at 0 is transferred to the bump 3.
Next, as shown in FIGS. 3C and 3D, when the chip 1 having the bump portions 3 formed on the electrode pads 2 is connected to the semiconductor substrate 6 having the conductive portions 5, the paste 4 The conductive portion 5 and the bump portion 3 are bonded by utilizing the adhesive force. afterwards,
After the paste 4 is cured by heating, FIG.
As shown in (e), the sealing resin 7 is injected between the chip 1 and the semiconductor substrate 6 and is heated again to thereby form the sealing resin 7.
Is to be cured.

[0004]

However, in the above-described chip mounting method, there is a problem that the bonding strength between the bump portion and the paste agent is weak, so that the bonding strength cannot be sufficiently secured and a defective connection occurs. there were.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and has as its object to provide a chip mounting method which secures the adhesion between a conductive portion and a bump portion of a semiconductor substrate and realizes stable electrical connection. It is intended for.

[0006]

According to a first aspect of the present invention, there is provided a chip mounting method comprising the steps of: providing a paste material on a bump portion provided on a chip;
A step of aligning the conductive portions 5 provided on the semiconductor substrate 6 with each other and disposing the chip 1 at a predetermined position on the semiconductor substrate 6 so as to face and connect or mount the chip 1. The method is characterized in that the surface of the first bump portion 3 is roughened and a step of providing the paste 4 on the bump portion 3 is provided.

According to a second aspect of the present invention, there is provided a chip mounting method comprising the steps of: providing a paste on a bump portion provided on a chip; and providing a conductive portion provided on the bump portion and a semiconductor substrate. And mounting or connecting the chip 1 at a predetermined position on the semiconductor substrate 6 by opposing the paste to the bumps 3 of the chip 1. Before the agent 4 is provided, a step of performing a plasma treatment on the bump portion 3 to perform a surface roughening process on the surface of the bump portion 3 is provided.

The bumps 3 include stud bumps having an arbitrary shape, solder bumps having an arbitrary shape, and solder balls having a substantially spherical shape. In addition, the paste 4 includes various substances such as a conductive adhesive and a flux. In addition, the conductive portion 5 includes any electrically conductive material such as an electrode pad and a conductive pattern.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS First, a first embodiment of the present invention will be described with reference to FIG. FIG. 1 is a schematic sectional view showing a chip mounting step according to the first embodiment of the present invention.

As shown in FIG. 1E, the chip mounting structure includes a chip 1 and electrode pads 2 provided on the chip 1.
And a bump portion 3 provided on the electrode pad 2 and a bump portion 3
The chip 1 and the semiconductor substrate so as to cover at least the paste 4 applied to the surface of the semiconductor substrate 6 having the conductive portion 5, the electrode pad 2, the bump 3, the paste 4, and the conductive portion 5. 6 and a sealing resin 7 injected between them.

Here, in the first embodiment, the transfer stage 10 is made of, for example, SUS304 and has a bottom 10
a is provided with a rough surface portion 11 having a large surface roughness where a is an arithmetic average roughness Ra of 0.1 μm or more.

In the first embodiment, the paste 4 provided in the transfer stage 10 is a conductive adhesive, and has a thickness of, for example, 40 ± 30 μm. The bump 3 is, for example, a gold stud bump having a diameter of about 90 μm, and the conductive part 5 is a conductive pattern.

Hereinafter, a chip mounting method will be described. First, as shown in FIGS. 1A and 1B, a bump portion 3 is formed on an electrode pad 2 provided on a chip 1. Then, the bump portion 3 formed on the electrode pad 2 of the chip 1 and the transfer stage 1
Zero alignment is performed. Then, the bump 3 and the transfer stage 10 are abutted with a load of, for example, 100 g / bump, and the surface of the bump 3 is brought into contact with the rough surface 11 to roughen the surface of the bump 3 and roughen the rough surface 8. Is formed, and the paste 4 filled in the transfer stage 10 is transferred to the surface of the bump portion 3.

Here, the surface roughness of the roughened portion 8 after the transfer is substantially the same as the roughness of the bottom 10a of the transfer stage 10.

The surface roughness of the roughened portion 8 of the bump portion 3 is roughened in accordance with the size of the bump portion 3. For example, when the diameter or size of the bump portion 3 is large, the surface is roughened.

As shown in FIGS. 1 (c) to 1 (e), the subsequent chip mounting method is the same as the method shown in the prior art, so that the description is omitted.

In this chip mounting method, a rough surface portion 11 having a large surface roughness is provided at the bottom of a transfer stage 10 for transferring the paste 4 to the bump portion 3.
Since the surface of the bump portion 3 is roughened by abutting the surface of the bump portion 3 to form the roughened portion 8, the adhesive force between the paste 4 and the bump portion 3 is increased. A chip mounting method that secures the adhesive force between the semiconductor device and the conductive portion 5 and realizes stable electrical connection can be provided.

Next, an embodiment showing another method of roughening the bump portion 3 will be described as a second embodiment of the present invention with reference to FIG.

FIG. 2 is a schematic sectional view showing a chip mounting step according to a second embodiment of the present invention. In the description of the common parts with the first embodiment, the same parts are denoted by the same reference numerals and the description thereof will be omitted.

In the second embodiment, a surface treatment using a plasma treatment is performed instead of the surface treatment method for the bump portion 3 shown in FIGS. 1A and 1B in the first embodiment.

Here, the plasma processing apparatus may be of a reduced pressure type in which processing is performed in a reduced pressure atmosphere or an atmospheric pressure type in which processing is performed under atmospheric pressure.

Hereinafter, a chip mounting method will be described. FIG.
As shown in (a), the surface of the bump portion 3 is irradiated with, for example, argon plasma 12 using a reduced pressure plasma processing apparatus (not shown), so that the surface roughness of the bump portion 3 is, for example, Ra 0.05 μm or more. Is formed.

Then, the paste 4 is provided on the bump 3 including the roughened portion 8 by the transfer method as shown in the prior art. In addition, as shown in FIGS. 2B to 2D,
The subsequent chip mounting method is the same as the method shown in the prior art, and thus the description is omitted.

The plasma processing time, processing power, and the like for the bump 3 are arbitrarily determined according to the size and material of the bump 3. For example, when the diameter and size of the bumps 3 are large, or when the bumps 3 made of a material whose surface is unlikely to be roughened are subjected to plasma processing, it is preferable to perform high-power long-time processing. Further, when the diameter and size of the bumps 3 are small, or when the bumps 3 made of a material whose surface is relatively easily roughened or a material which is easily damaged by heat are subjected to plasma processing, low-power, short-time processing is required. It is preferred to do so.

In such a chip mounting method, the bump portion 3 is subjected to plasma treatment to roughen the surface of the bump portion 3 to form a roughened portion 8 so that the paste agent 4 and the bump portion 3 adhere to each other. Since the force is increased, it is possible to provide a chip mounting method that secures the adhesion between the bump portion 3 and the conductive portion 5 and realizes stable electrical connection.

Here, in the case of using a plasma processing apparatus of the atmospheric pressure type instead of the reduced pressure type in the second embodiment, for example, the surface of the bump portion 3 is irradiated with oxygen plasma (not shown) to 3 (gold stud bump) can be formed with a roughened portion 8 having a surface roughness of, for example, Ra 0.05 μm or more.

In the first and second embodiments, when the bump portion 3 is a solder ball (not shown) or a solder bump (not shown), the paste 4 is made of conductive adhesive. A flux (not shown) is used instead of the agent. In addition, the method of providing the flux to the solder portion 3 is the same as the method of providing the flux by transfer as in the first embodiment, but the roughening portion 8 is formed on the bump portion 3 as shown in FIG. 2A of the second embodiment. After formation, a mask (not shown) is provided at a desired position on the surface of the bump portion 3 so that the roughened portion 8 is exposed, and the mask is applied to a portion including the exposed roughened portion 8. It may be a method.

[0028]

As described above, in the chip mounting method according to the first aspect of the present invention, a step of providing a paste on a bump portion provided on a chip, and a step of providing a paste on the bump portion and the semiconductor substrate. A step of aligning the conductive portions with each other and arranging and connecting or placing the chip at a predetermined position on the semiconductor substrate so as to face each other, wherein a surface of the bump portion of the chip is provided. And the step of providing the paste on the bump portion, so that the surface of the bump portion is roughened, the conductive portion of the semiconductor substrate and the bump portion And a chip mounting method that realizes stable electrical connection by ensuring the close contact force. Further, by performing the step of roughening the surface of the bump section and the step of providing the paste agent on the bump section substantially at the same time, there is an effect that the chip mounting time can be made equal to the conventional one.

According to a second aspect of the present invention, there is provided a chip mounting method, wherein a step of providing a paste on a bump portion provided on a chip, and a step of positioning the bump portion and a conductive portion provided on a semiconductor substrate with respect to each other. Prior to providing the paste on bumps of the chip, the step of: mounting the chip at a predetermined position on the semiconductor substrate facing and connecting or mounting the chip. Since it is provided with a step of performing a plasma treatment on the bump portion to perform a surface roughening process on the surface of the bump portion,
A chip mounting that secures adhesion between a conductive portion of the semiconductor substrate and the bump portion and realizes stable electrical connection because the surface of the bump portion is roughened by performing the plasma treatment on the bump portion. A method could be provided.

[Brief description of the drawings]

FIG. 1 is a schematic sectional view showing a chip mounting step according to a first embodiment of the present invention.

FIG. 2 is a schematic sectional view showing a chip mounting step according to a second embodiment of the present invention.

FIG. 3 is a schematic sectional view showing a chip mounting step according to a conventional example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Chip 2 Electrode pad 3 Bump part 4 Paste agent 5 Conductive part 6 Semiconductor substrate 7 Sealing resin 8 Roughened part 10 Transfer stage 10a Bottom part 11 Roughened part 12 Plasma

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Kazunori Kuzuhara 1048 Odakadoma, Kadoma City, Osaka Prefecture F-term in Matsushita Electric Works, Ltd.

Claims (2)

[Claims] A step of providing a paste on a bump provided on the chip; and positioning the bump and a conductive part provided on a semiconductor substrate with each other by positioning the chip on a predetermined position on the semiconductor substrate. And a step of connecting or placing the chips facing each other, comprising a step of roughening the surface of the bumps of the chip and providing the paste on the bumps. A chip mounting method characterized in that: A step of providing a paste on a bump portion provided on the chip; and positioning the bump portion and a conductive portion provided on a semiconductor substrate with each other by positioning the chip on a predetermined position on the semiconductor substrate. And a step of connecting or placing them facing each other, before providing the paste on bump portions of the chip,
A chip mounting method comprising a step of performing a plasma treatment on the bump portion to perform a roughening process on a surface of the bump portion.