JP2001196407A - Semiconductor device and method of forming semiconductor device - Google Patents

Abstract

(57) [Summary] [Problem] To prepare an IC package in a wafer state,
To provide an IC package of the same size as a chip. SOLUTION: After bonding a bump to an electrode pad in a wafer state, a protective material is applied to expose a bump portion. Thereafter, the wafer is cut along a scribe line to complete an IC package.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a structure of a so-called chip size package having the same size as an IC chip, and a method of manufacturing the same.

[0002]

2. Description of the Related Art In a so-called chip size package which has been manufactured, an IC package is manufactured after separating an IC chip into one.

[0003]

In order to put an IC in an IC package, a considerable margin must be taken, and the actual size of the IC package is considerably larger than that of an IC chip. . Also, I
The process of manufacturing the C package was complicated and long, so it was expensive and the production period was long.

[0004]

SUMMARY OF THE INVENTION In order to solve the above problems, the present invention provides an IC package in a wafer state, and provides an IC package having the same size as an IC chip. That is, after bonding the bumps to the electrode pads in a wafer state, a protective material is applied to expose the bump portions. Thereafter, the wafer is cut along a scribe line to complete an IC package.

[0005]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention relates to a technique for providing an IC package having the same size as an integrated circuit (IC) chip. Hereinafter, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a sectional view of an IC package showing a structure of the present invention formed in a wafer size. An electrode pad 2 is formed on a surface of a semiconductor substrate 1. The surface of the semiconductor substrate 1 is covered with a protective film 3. An integrated circuit is formed in a semiconductor substrate. In FIG. 1, the integrated circuit in the semiconductor substrate is omitted.

An IC chip is configured as described above. In the present invention, the bumps 4 are bonded to the electrode pads 2 of the IC chip. The shape of the bump 4 is convex as shown in FIG. The surface of the IC chip is covered with a protective material 5.

The above IC package has the following features.

(1) It is the same size as an IC chip.

(2) Since the bumps 4 are cut by the protective material 5, the IC chip is completely covered with the protective material. This prevents foreign substances from entering the IC chip from the external environment. For example, since there is no intrusion of external moisture, corrosion of the electrode pads, which is a problem due to the moisture of the IC chip, does not occur.

(3) The pillar portion 4a of the bump 4 is made of a protective material 5
Since it is more protruding, connection with an external electrode is easy. This will be described with reference to FIG. FIG. 2A shows FIG.
FIG. 4 is a cross-sectional structural view of one IC package in a state where an assembly of IC packages formed with the same wafer size is singulated. FIG. 2B shows a state where the IC package of FIG. 2A is mounted on a mounting board. The wiring 17 is formed on the surface of the mounting board 16. The wiring 17 and the pillar portion 14a of the bump 14 are adhered. Since the pillar portions 14a of the bumps 14 protrude from the protective material 15, the connection with the external wiring 17 is facilitated.

(4) Since the protection material 5 firmly holds the IC chip, the strength of the IC package is significantly improved as compared with the strength of the IC chip alone.

(5) Since the structure is simple, manufacturing costs including material costs are very low.

As described above, the IC package according to the present invention can be used as a chip size package.

Next, a method of manufacturing an IC package according to the present invention will be described in detail.

FIG. 3A is a view showing a wafer state at a stage where an IC chip has not been cut yet. There are many ICs in a wafer. 21 is a semiconductor substrate, 22 is an electrode pad, and 23 is a protective film. Many semiconductor elements are formed in the semiconductor substrate 21. The semiconductor substrate 21
It is a compound semiconductor such as a silicon (Si) semiconductor or gallium arsenide, or another semiconductor. The material of the electrode pad 22 is aluminum (Al), an aluminum alloy, or aluminum containing an impurity element. Or copper (C
u), copper alloys, copper containing impurities, or other metals. The material of the protective film 23 is a silicon oxide film (SiO2), a silicon nitride film (SiNx), a polyimide film, or another insulating film.

Next, as shown in FIG. 3B, the bumps 24 are bonded to the electrode pads 22 in a wafer state in which a large number of ICs are formed.

FIG. 3 (c) is an enlarged view of one electrode pad of FIG. 3 (b). The shape of the bump 24 is shown in FIG.
It is formed so as to have a convex shape as shown in FIG.
As one forming method, there is a method using a wire bonder device.

That is, in FIG.
Is formed into a round metal ball 35 with a wire bonding apparatus. Next, as shown in FIG.
5 is pressed against the electrode pad 32 of the IC, and the metal ball 35 and the electrode pad 32 of the IC are bonded by a method such as thermocompression bonding or ultrasonic compression bonding. Next, as shown in FIG. 4C, the metal wire 34 is cut at an appropriate length. The above process is performed at the wafer level. However, the height of the bumps 36 varies from the viewpoint of the wafer size. In order to make the overall height uniform, a process called beveling is performed after the process of FIG. May be added.

Gold (A) is used as a material for the bumps 34 and 35.
u), palladium (Pd), aluminum (Al), silver (Ag), a solder alloy of lead (Pd) and tin (Sn), silver (A
g) and an alloy of tin (Sn) and other metals.

Next, as shown in FIG.
5 is attached. FIG. 3E is an enlarged view of one electrode portion of FIG. 3D. The protective material 25 is a liquid material and can be applied to the entire wafer. The liquid thickness when applied must be determined in consideration of the final thickness after curing. That is, the liquid thickness after application is adjusted so that the pillars of the bumps 24 are sufficiently exposed and the pillars of the bumps 24 are secured to the extent that they adhere to the wiring on the mounting board during mounting. After the application, the liquid is solidified by baking at an appropriate temperature. By appropriately selecting this bake temperature, the material 25 becomes a more stable protective material and mechanically and chemically strengthens the IC.

Now that a number of IC packages have been completed in the wafer, the process of separating these ICs one by one will now be described.

The wafer is cut along a scribe line in the wafer by using a dicing apparatus, and separated into individual IC packages. Thereby, an individual IC package is formed. In FIG. 3, the protective material 2 is placed in the middle of the pillar portion 24a of the bump.
5, the protective material 45 may be provided below the horizontal portion of the bump, as shown in FIG.

[0024]

As described above, the IC in the wafer state is used as described above.
Since the package is created, the number of processes is reduced, and the cost and the delivery time can be significantly reduced.

Also, since the bumps are used and the protection material covers the horizontal portions of the bumps, the reliability and quality are very high.

[Brief description of the drawings]

FIG. 1 is a wafer-sized IC that is a semiconductor device of the present invention.
FIG. 3 is a diagram illustrating a structure of a package.

FIG. 2 is a diagram showing a mounted state of the semiconductor device of the present invention.

FIG. 3 is a diagram illustrating a method of manufacturing a semiconductor device according to the present invention.

FIG. 4 is a diagram illustrating a method of forming a bump used in the semiconductor device of the present invention.

FIG. 5 is another embodiment of the method of manufacturing a semiconductor device according to the present invention.

[Explanation of symbols]

 1, 11, 21, 31, 41 Semiconductor substrate 2, 12, 22, 32, 42 Electrode pad 3, 13, 23, 33, 43 Protective film 4, 14, 24, 36, 44 Bump 5, 15, 25, 45 Protective material 4a, 14a, 24a, 44a Column of bump

Claims (5)

[Claims] 1. A convex bump is adhered to an electrode pad of a semiconductor substrate on which a semiconductor element is formed, and a part of a horizontal part and a pillar part of the convex bump are exposed, and the other part is covered with a protective material. A semiconductor device characterized in that: 2. The semiconductor device according to claim 1, wherein the convex bump pillar portion protrudes from the protective material. 3. A convex bump is adhered to an electrode pad of a semiconductor substrate on which a semiconductor element is formed, and a pillar portion of the convex bump is exposed and another portion is covered with a protective material. Semiconductor device. 4. A convex bump is adhered to an electrode pad of a semiconductor substrate on which a semiconductor element is formed, a part of a horizontal part and a pillar part of the convex bump are exposed, and the other part is covered with a protective material. Forming a semiconductor element in a semiconductor substrate, bonding a bump to an electrode pad of the semiconductor element, applying a material for protecting the semiconductor element, and heat-treating the protective material in the semiconductor device. A method for manufacturing a semiconductor device, comprising: 5. The method according to claim 4, wherein the convex bumps are formed using a wire bonding apparatus.