JPH03241756A - Apparatus and method of mounting semiconductor integrated circuit - Google Patents

Abstract

PURPOSE:To contrive to improve a productivity by putting a solder in a heat- resisting container with a pipe, by fusing the solder through a heater wound round the outer periphery of the heat-resisting container and by discharging a constant quantity of solder from a nozzle of extra fine diameter provided continuously at the lower part of the heat-resisting container. CONSTITUTION:A solder 4 contained in a heat-resisting container 5 is heat-fused by a heater 6 around the container, air is adjusted and fed from a pipe 7 provided in the upper part, and the pressure of the fed air causes the fused solder 4 to drop correctly by constant quantities from a nozzle 8 of extra fine diameter provided at the lower part of the heat-resisting container 5 successively onto an electrode 2 on a mounted substrate 1 coated with flux so that a solder bump 9 is formed. In this case, a solder discharge quantity is adjusted from the thickness of a photoresist 3 and the size of the electrode 2 and the granular solder bump 9 is formed immediately from the point of time when the solder drops. Thus, the solder bump of constant height is formed and granulated simultaneously with the discharge so that one process is omitted.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a semiconductor integrated circuit mounting apparatus and method for forming solder bumps and the like on electrodes on mounting boards of general electrical appliances such as computers.

Conventional technology In order to place a bare IC chip on a mounting board as a high-density mounting method, aluminum C was used as the external electrode of the IC chip.
1, e) To connect the electrode and the electrode of the mounting board,
A granular connection called a bump is required on at least one electrode on the mounting board or the IC chip. Conventionally, lead or tin was formed as the bump using a vacuum evaporation method or plating method, and then heat-treated to form particles, or cream solder was printed on the electrode and then heat-treated to increase the height. A granular bump of about 30 to 50 μm was formed and used.

Problems to be Solved by the Invention In the conventional bump forming method using the vacuum evaporation method or the plating method, it takes time to form a bump with a height of about 3 to 50 μm, and the productivity is not good.

On the other hand, with the method of printing 5 cream solder, many electrodes can be thickly printed at once, but during the subsequent heat treatment, the cream solder may burst due to flux, etc., generating small solder particles and scattering around them. , a short may occur between the electrodes.

The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to provide a semiconductor integrated circuit mounting apparatus and a mounting method in which molten solder is dropped.

Means for Solving the Problems In order to achieve the above object, the present invention includes a method in which solder is placed in a heat-resistant container equipped with a pipe for applying air pressure at the top, and the solder is melted by a heater sprinkled around the outer periphery of the heat-resistant container. , a certain amount of solder is applied from an ultra-thin diameter nozzle that is continuously provided at the bottom of a heat-resistant container.

In the present invention, precise pressure is applied to the surface of the molten solder from the upper pipe at the bottom of the groove as described above, and as a result, a certain amount of solder is dripped from the lower nozzle having an extremely small diameter.

At that time, if the parts of the mounting board other than the electrodes are covered with 7-hole resist, a certain amount of solder dropped onto the electrodes will form bumps of uniform height.

EXAMPLE Hereinafter, an example of the present invention will be described with reference to FIGS. 1 to 6.

1. First, in FIG. 1, an electrode 2 is formed on a mounting board 1 by vacuum evaporation, a photorin process, or the like.

Furthermore, the area around the electrode 2 has a thickness of approximately 30 to 50 μm.
A photoresist 3 of 7 is applied by seven etching steps. FIG. 2 shows the entire so-called mounting board 1. Flux is applied onto this electrode 2.

On the other hand, place the heat-resistant container 6 containing the solder 4 in the surrounding area 5 ・＼
-7 Melt by heating to about 250'C with a heater 6, adjust and send air through a pipe 7 installed at the top, and the pressure will cause an ultra-thin nozzle 8 with a diameter of about 40/1 m installed at the bottom of the heat-resistant container 5. Then, a certain amount of the molten solder 4 is sequentially dropped onto the electrode 2 on the mounting board 1 coated with the aforementioned 7 lux. Then, solder bumps 9 as shown in FIG. 1 are formed.

This is the same operation as a normal dispenser.

The amount of solder applied is adjusted based on the thickness of the photoresist 3 and the size of the electrode 2, and granular solder bumps 9 are formed immediately after dropping, and the height is about 60μ1 from the photoresist 3.
rank. The ultra-fine nozzle 8 is placed on the top 60 of the photoresist 3.
The fim is moved horizontally to form solder bumps 9 on all of the electrodes 2, and then flux is applied thereon.

On the other hand, FIG. 3 shows the IC chip 1 mounted on the aforementioned mounting board.
An external view of o is shown. There is a mu-e electrode 11 on the surface of the mu-e electrode 11 as an external electrode, and the surface of this mu-e electrode 11 is coated with chromium, copper, gold, etc. for soldering with the solder bumps 9 on the mounting board 1 to prevent soldering. Gold 6.\- is applied as a barrier metal 12 as shown in FIG. 5, which will be described later, by vapor deposition or plating to a film thickness of about 1 μm. As shown in FIG. 4, this is stacked downward at a predetermined position on the mounting board 1, and after accurate positioning, is heated and pressed using a top-up jig to join. This joined state is shown in FIG. There are granular solder bumps 9 on the electrodes 2 on the mounting board 1, and on the upper surface there are I (3 chips 10) facing downward.
There is.

The granular solder bumps 9 join the electrodes 2 of the mounting board 1 and the barrier metal 12 in contact with the mu electrodes 11 of the IC chip 10.

After this, wash with a solvent to remove the flux-I
A resin coating is applied to the CIC chip 10 to protect it.

Although this embodiment describes the case where the bumps 9 are formed on the electrodes 2 on the mounting board 1, the present invention can also be applied to the case where the bumps 9 are formed on the electrodes on the IC chip 10.

In this case, a barrier metal or the like used for the electrode 2 on the mounting board 1 is used for the electrode 11 of the IC chip 10.

Page 7 Effects of the Invention As is clear from the above embodiments, according to the present invention, a photoresist is formed around the solder bumps connecting the mounting board and the IC chip by applying molten solder through a nozzle using a dispenser. Forming the solder bump by dropping it onto the electrode is quick and requires simple equipment, and because it uses a single dispenser, the amount of solder applied is stable and it is possible to form solder bumps of a constant height.

Moreover, they are called unnecessary solder balls, such as when printing cream solder and reflowing it. There is also no generation of many small particles that short-circuit between the electrodes.

Furthermore, instead of forming particles by melting the solder in an inert gas atmosphere after applying the solder as in the conventional method, the particles are formed at the same time as application, which has the advantage of saving one step.

[Brief explanation of drawings]

FIG. 1 is a schematic cross-sectional view of a semiconductor integrated circuit mounting apparatus according to the present invention, FIG. 2 is a perspective view of a mounting board, FIG. 3 is a perspective view of an IC chip mounted on a mounting board, and FIG. 4 is a perspective view of an IC chip mounted on a mounting board. A perspective view showing the state in which the IC chip is placed, Figure 5 shows the mounting board and I
FIG. 3 is an enlarged cross-sectional view showing a state in which a C chip is joined. 1... Mounting board, 2... Electrode, 3...
...Photoresist, 4...Solder, 5...
... Heat-resistant container, 6 ... Heater, 7 ...
...Pipe, 8...Extremely small diameter nozzle, 9...
...Solder bump.

Claims (3)

[Claims] (1) A heat-resistant container equipped with a heater on the outer periphery for containing solder, a pipe provided continuously at the top of the heat-resistant container for applying air pressure to the solder surface in the heat-resistant container, and a pipe for applying air pressure to the solder surface in the heat-resistant container; A semiconductor integrated circuit mounting device consisting of an ultra-thin diameter nozzle continuously provided at the bottom for dispensing a certain amount of solder. (2) a step of providing a photoresist around the electrodes of the mounting board; and a step of dropping solder onto the electrodes of the mounting board using the semiconductor integrated circuit mounting apparatus according to claim 1;
A method for mounting a semiconductor integrated circuit comprising the steps of superimposing and thermocompression bonding an electrode of a mounting board onto which the solder has been dropped onto an electrode on a chip having a semiconductor integrated circuit. (3) providing a photoresist around the electrodes on the chip having the semiconductor integrated circuit, and applying solder onto the electrodes on the chip having the semiconductor integrated circuit using the semiconductor integrated circuit mounting apparatus according to claim 1; A method for mounting a semiconductor integrated circuit comprising the steps of dropping the solder, and stacking and thermocompressing an electrode on a chip having a semiconductor integrated circuit onto which the solder has been dropped onto an electrode of a mounting board.