JPS5821429B2 - How to use hand-held equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method of manufacturing a semiconductor integrated circuit.

The present invention relates to a method for forming protruding electrodes (bumps) on the pad portion of a chip.
This is a method for transfer printing of conductive paste such as l-based.

Furthermore, by selecting a conductive paste, the aluminum wiring can be alloyed and the bumps can be fired at the same time.

In recent years, since semiconductor integrated circuits with a large number of wire-bonded pads have problems in terms of productivity and reliability, wireless bonding methods such as the flip-chip method and the beam lead method have been proposed and put into practical use.

Among these methods, there is a bump method in which metal protrusions are provided on the electrode terminals of a semiconductor chip as a method for manufacturing flip chip devices, and methods include burying Au-plated Cu balls or mask-evaporating D and L using solder balls. It is being

Furthermore, a method has been proposed in which an Al cone is formed from Al foil using a coining tool to form an electrode of a chip.

[The present invention relates to a method for making this bump, and will be described below based on Examples.

100OOA of A7 for wiring was deposited on the C-MOS and LSI wafers on which the diffusion and insulating film had been formed, and heat treatment was performed at 300°C for 15 minutes in a nitrogen atmosphere to improve the adhesion of A, and a wiring pattern was formed by photo-etching. do.

Next, a CVD 5io2 film of 800 OA is formed as a protective film at 430° C., and a hole is made in the protective film of the pad portion by hot etching.

As shown in Fig. 1, a stainless steel plate 1 having four parts corresponding to the bump shape is covered with an Au-Pt based conductive paste 2.
into the recess, press the tampon 3 made of gelatin against the stainless steel plate, and transfer the conductive paste to the tampon.

It is pressed onto the above-mentioned wafer 4 and transfer printed.

This is heat-treated at 550° C. for 10 minutes in an oxygen atmosphere while volatilizing the binder of the conductive paste, and the bumps are fired at the same time as the wiring layer 1 is alloyed.

FIG. 2 shows a cross-sectional view thereof, and shows that A[wiring pad portion 50 has a dimension of 150 μm, and a pad portion of the protective film 6 has a hole size l/′ of 1140 μm.

The dimensions of the Au--Pt conductive bump 7 were approximately 100 .mu.m wide and approximately 10 .mu.m thick, and the ohmic contact with the pad was established and the adhesion was also good.

When Au-based conductive paste was used, heat treatment at about 560° C. in an oxygen atmosphere was sufficient, and in the case of A7-based conductive paste, the objective was achieved at 530° C. in a nitrogen atmosphere.

Further, although an example of transfer printing using a tampon has been shown, screen printing using a stainless steel mesh is also possible.

As described above, the present invention uses Au for the A77 wiring pad of a semiconductor chip.
This is a method that transfers and prints a conductive paste such as A-based, Au-Pt-based, or Al-based, and by selecting a conductive paste, it is possible to simultaneously alloy the Al wiring and fire the bumps. This method significantly improves productivity compared to conventional bump manufacturing methods.

Furthermore, in the present invention, the conductive paste is placed in a plate having a concave portion corresponding to the bump shape, transferred to a pressing jig made of gelatin, rubber, etc. that is elastically deformable, and then transferred to the pad portion. There is no need to prepare a corresponding number of jigs, especially if there are a large number of pads.
It allows accurate positioning, and has the advantage that there is no need to change the shape of the jig due to differences in the components and viscosity of the metal paste.

Furthermore, since the bumps are formed by firing the conductive paste at a temperature below the temperature at which wiring metals in integrated circuits become alloyed, it is possible to form bumps with sufficient ohmic contact with the pads and good adhesion. It is.

[Brief explanation of drawings]

FIG. 1 shows an embodiment of the present invention, in which 1 is a stainless steel plate with recesses, 2 is a conductive paste, 3 is a tampon, 4 is a semiconductor wafer, and FIG. 2 is a cross-sectional view of a bump-formed structure. 5 is an A7 wiring pad, 6 is a protective film made of CVD sio 2 film, and 7 is an Au-P
T-type bump.

Claims (1)

[Claims] 1 After forming a protective film on a semiconductor integrated circuit, holes are made in the protective film at the electrode extraction portions to form pads, and conductive paste is placed in a plate having a recess corresponding to the bump shape, and a conductive paste is made of gelatin, rubber, etc. Transfer the conductive paste to a pressing jig that is elastically deformable, transfer the conductive paste to the pad portion, and bake the conductive paste at a temperature below the temperature at which the distribution metal in the semiconductor integrated circuit becomes alloyed to form bumps. 1. A method of manufacturing a semiconductor integrated circuit, comprising: forming a semiconductor integrated circuit.