JP2001326248A - Method for manufacturing semiconductor device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for manufacturing a semiconductor device which can deal with cost reduction. SOLUTION: A solder sheet is placed over an electric circuit board 1 and a solder foil is punched at a part on the circuit wiring 12 of the electric circuit board 1 being bonded to a semiconductor integrated circuit element 5. It is then transferred onto the circuit wiring 12 and unnecessary solder foil is removed thus forming solder bumps 4 on the circuit wiring 12. Subsequently, the external bonding electrodes 6 of the semiconductor integrated circuit element is placed on the solder bumps 4 and heated, fused and cooled thus solder bonding the semiconductor integrated circuit element 5 and the electric circuit board 1.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a semiconductor device formed by joining a semiconductor integrated circuit element and an electric circuit board, and more particularly, to a semiconductor integrated circuit element using a solder alloy. And the electric circuit board.

[0002]

2. Description of the Related Art Conventionally, a manufacturing method generally used for soldering a semiconductor integrated circuit element to an electric circuit board is as follows. The conventional manufacturing method will be described with reference to FIGS.

First, as shown in FIG. 4, a surface of a semiconductor integrated circuit element 5 is coated with copper (C) having good wettability with solder.
A metal thin film 31 made of u) is formed.

Next, as shown in FIG. 5, a resist film is formed on the entire surface of the metal thin film 31, and only the resist film 32 on the external bonding electrode portion of the semiconductor integrated circuit element 5 is removed by photolithography to remove the resist film. The film opening 32a is formed.

Next, as shown in FIG. 6, electrolytic plating is performed in a solder plating solution using the metal thin film 31 as a cathode, and a predetermined amount of solder 33 is deposited only on the resist film opening 32a.

Next, as shown in FIG. 7, the resist film 32 used as the plating stopper film is peeled off.

Next, as shown in FIG. 8, the metal thin film 31 is removed by etching so that only the solder 33 deposition portion of the metal thin film 31 is left.

Next, as shown in FIG. 9, the deposited metal portion of the solder 33 is heated and melted to form an alloy, thereby forming a bonding bump 33a.

Next, as shown in FIG.
Semiconductor integrated circuit element 5 having 3a formed thereon and electric circuit board 3
5 are placed facing each other at a predetermined position, and the connection bump 33a and the circuit wiring 36 are brought into contact with each other and heated to melt the solder and complete the joining.

The above-described manufacturing method is a method of manufacturing a semiconductor device using photolithography and plating as core technologies, and therefore has the advantage that it can be easily adapted to high density and the shape and size of the junction are stable. is there. Also, there is an advantage that the devices to be used can be shared in a considerable part with the semiconductor integrated circuit device manufacturing device.

[0011]

However, in the conventional manufacturing method, the manufacturing equipment is expensive, the initial cost for each semiconductor integrated circuit element is high, the deposition composition of solder plating is apt to vary, and The processing of varieties has the disadvantage of being very expensive.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a semiconductor device which can solve the above-mentioned problems, can manufacture a semiconductor device at low cost, and can stabilize the alloy composition of solder bumps. It is to provide a manufacturing method.

[0013]

In order to achieve the above object, a method of manufacturing a semiconductor device according to the present invention employs the following steps.

According to the method of manufacturing a semiconductor device of the present invention, there is provided a method of manufacturing a semiconductor device formed by joining a semiconductor integrated circuit element and an electric circuit board. Forming a solder bump on the electric wiring by punching out the solder foil on the electric wiring of the electric circuit board at the part to be joined with the semiconductor integrated circuit element, transferring it to the electric wiring and transferring it, and removing the unnecessary part solder foil And a step of superposing an external bonding electrode portion of the semiconductor integrated circuit element on the solder bump portion, heating and melting the cooled portion, and then cooling the semiconductor integrated circuit device and the electric circuit board. Features.

[Operation] In response to these conventional technical problems,
The basic technique of the present invention is to punch a solder sheet and transfer it to a desired location on an electric circuit board. This makes it possible to form solder bumps by metal foil transfer technology.

As a result, in the method of manufacturing a semiconductor device according to the present invention, bump formation can be performed only by an inexpensive manufacturing apparatus, and a photomask is not required. In addition, since the solder composition depends only on the solder foil, it is possible to solve the problems of the prior art, such as easy management.

In the method of manufacturing a semiconductor device according to the present invention, since a hitting pin or a hitting pin array is used as a metal foil transfer technique, a solder foil transfer using an impact printer technique can be performed. it can.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A method for manufacturing a semiconductor device according to a preferred embodiment of the present invention will be described with reference to the drawings. Hereinafter, a description will be given with reference to FIGS. 1, 2, and 3.

First, as shown in FIG. 1, an electric circuit board 1 is formed by laminating a circuit wiring 12 on a base material 11. The substrate 11 of the electric circuit board 1 is made of glass fiber reinforced epoxy resin having a thickness of 0.4 mm, and the circuit wiring 12 is a copper wiring having a thickness of 18 μm, which is plated with nickel and gold having a thickness of 1 μm or less. Is used.

This is because a nickel plating film and a gold plating film having a thickness of 1 μm or less can be easily formed by an electroless plating method. Since the surface of the circuit wiring 12 is gold, a special surface treatment is required at the time of solder transfer described later. There is also a merit that does not.

Next, a solder sheet 2 is placed on the electric circuit board 1.
Are arranged to overlap. This solder sheet 2 has a thickness of 3
0 μm eutectic solder (Sn 68% + Pb 32%) foil 21
Is laminated on a SUS304 sheet substrate 22 having a thickness of 15 μm.

After the electric circuit board 1 and the solder sheet 2 are overlaid, the solder sheet at the solder bump forming position on the circuit wiring 12 is hit with the hitting pins 3 so that the solder foil 21 at that portion is removed from the solder sheet 2 by the circuit wiring. Transfer onto No. 12.

The tip diameter of the striking pin depends on the size of the solder bump to be formed. In the embodiment of the present invention, a striking pin made of super steel (tungsten carbide) having a tip diameter of 150 μm is used.

In order to transfer the solder foil 21 onto the circuit wiring 12 by the hitting pins 3, the hitting load by the hitting pins 3 must be appropriate. If the impact load is too small, the transfer of the solder foil 21 becomes insufficient. If the impact load is excessive, the sheet material 22 is punched out and the material of the sheet material 22 remains on the bump surface.

It has been experimentally confirmed that the proper range of the impact load during the transfer of the solder foil depends on the material of the solder foil 21 and the material of the sheet substrate 22. In the manufacturing method of the present invention, the above-mentioned material was 20 to 80 kg / cm ² . In addition, the time for applying a hit with the hitting pin 3 is about 0.02.
Seconds.

In the embodiment of the present invention, the actual striking pins are arranged in a 16.times.16 arrangement (interval of 400 .mu.m), and solder foils at a plurality of positions are simultaneously punched to form solder bumps.

Thus, the solder bumps 4 are formed on the circuit wirings 12 as shown in FIG.

After the formation of solder bumps (solder transfer) at required locations is completed, the solder sheet 2 and the striking pins 3 are removed from the electric circuit board 1 and the semiconductor integrated circuit elements 5 are connected to the external bonding electrodes 6 of the semiconductor integrated circuit elements. Overlap with each other in a positional relationship facing the solder bumps 4.

As the external bonding electrode 6 of the semiconductor integrated circuit element, an aluminum electrode film having a thickness of 1 μm or less plated with nickel and gold is used.

In general, aluminum and solder have poor wettability, and the aluminum electrode film itself cannot be expected to have good bonding at the time of solder melting described later.

This is because a nickel plating film and a gold plating film having a thickness of 1 μm or less can be easily and inexpensively formed by electroless plating.

When the electric circuit board 1 and the semiconductor integrated circuit element 5 are overlaid and heated to a temperature higher than the melting temperature of the solder bump 4, the solder bump 4 is melted, and the circuit wiring 12 and the external bonding electrode 6 of the semiconductor integrated circuit element are connected. Connected.

In this state, when heating is stopped and cooling is performed, bonding between the electric circuit board 1 and the semiconductor integrated circuit device 5 is completed.

After the joining is completed, the gap between the electric circuit board 1 and the semiconductor integrated circuit element 5 is filled with an epoxy-based sealing resin.
The semiconductor device according to the present invention is completed by curing the sealing resin. FIG. 3 is a schematic cross-sectional view of the completed semiconductor device. Thus, an optimal embodiment of the present invention is completed.

In the manufacturing method of the above-described preferred embodiment of the present invention, glass substrate reinforced epoxy resin is used for the base material 11 of the electric circuit board 1 and 18 μm The copper wiring is plated with nickel and gold with a thickness of 1 μm or less.

As the external bonding electrode 6 of the semiconductor integrated circuit device, an aluminum electrode film was used in which nickel plating and gold plating having a thickness of 1 μm or less were applied.

However, the simple formation of solder bumps according to the present invention cannot be carried out without the above-mentioned material constitution. For example, even if the circuit wiring 12 is formed only of copper, the solder bumps can be formed in exactly the same manner.

The same applies to the constituent material of the electric circuit board 1.
Various materials such as C and ceramic can be used.

The configuration of the solder sheet can be changed in accordance with the required thickness of the solder foil. In this case, the above-mentioned embodiment can be implemented only by adjusting (optimizing) the impact load by the impact pin and the impact application time. The same solder bump formation as in the embodiment can be performed.

[0040]

As described above, according to the present invention, it is possible to manufacture a semiconductor device at a low cost, which cannot be achieved conventionally, such as the manufacture of a semiconductor device corresponding to a small number of semiconductor integrated circuit elements. Further, there is also an effect that the initial investment amount is reduced as compared with the conventional semiconductor device mounting.

Further, in the present invention, since a solder foil is used as a raw material of the solder bump, the alloy composition of the solder bump can be easily controlled within a certain range as compared with the conventional plating deposition method, and can contribute to stabilization of quality.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view illustrating a method for manufacturing a semiconductor device according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view illustrating a method of manufacturing a semiconductor device according to an embodiment of the present invention.

FIG. 3 is a cross-sectional view illustrating the method for manufacturing the semiconductor device according to the embodiment of the present invention;

FIG. 4 is a cross-sectional view illustrating a method of manufacturing a semiconductor device according to a conventional technique.

FIG. 5 is a cross-sectional view illustrating a method of manufacturing a semiconductor device according to a conventional technique.

FIG. 6 is a cross-sectional view illustrating a method for manufacturing a semiconductor device according to a conventional technique.

FIG. 7 is a cross-sectional view illustrating a method for manufacturing a semiconductor device according to a conventional technique.

FIG. 8 is a cross-sectional view illustrating a method of manufacturing a semiconductor device according to a conventional technique.

FIG. 9 is a cross-sectional view illustrating a method of manufacturing a semiconductor device according to a conventional technique.

FIG. 10 is a cross-sectional view illustrating a method of manufacturing a semiconductor device according to a conventional technique.

[Explanation of symbols]

1: Electric circuit board 2: Solder sheet
3: hitting pin 4: solder bump 5: semiconductor integrated circuit element 6: external connection electrode of semiconductor circuit element 11: base material 12: circuit wiring 21: solder foil 2
2: Sheet base material 31: Metal thin film with good wettability with solder 32:
Resist film 32a: Opening of resist film 33: Solder 33a: Connection bump 35: Electric circuit board
36: Circuit wiring

Claims (3)

[Claims] 1. A method of manufacturing a semiconductor device formed by joining a semiconductor integrated circuit element and an electric circuit board, wherein a solder foil is laminated on the electric circuit board surface, and Forming a solder bump on the electrical wiring by punching out the solder foil at a portion to be joined with the semiconductor integrated circuit element, transferring the transferred foil onto the electrical wiring, and then removing the unnecessary portion of the solder foil; and forming a solder bump on the electrical wiring. A method of superposing an external bonding electrode portion of a semiconductor integrated circuit element, heating, melting, and then cooling, and soldering the semiconductor integrated circuit element and an electric circuit board. . 2. The method according to claim 1, wherein the step of punching the solder foil uses a hitting pin. 3. The method according to claim 1, wherein the step of punching the solder foil uses a hitting pin array.