JPH0221653B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a method of manufacturing a semiconductor device using a transfer bump method for high-density, thin, and compact packaging of semiconductor elements and the like.

Conventional configurations and their problems In recent years, semiconductor elements such as ICs and LSIs have been introduced into the fields of various home appliances and industrial equipment. In order to save resources and power, or to expand the scope of use, these household electrical appliances and industrial equipment are being made more multifunctional, smaller, and thinner, so-called portable.

In order to make semiconductor devices portable, there has been a demand for smaller and thinner packaging. After the diffusion process and electrode wiring process have been completed, the silicon slice is cut into chips for each semiconductor element, and electrode leads are taken out from the aluminum electrode terminals provided around the chip to external terminals for ease of handling and for mechanical protection. packaged. Normally, DIL, chip carrier, flip chip, film carrier methods, etc. are used for packaging these semiconductor devices, but the film carrier method is promising for the above-mentioned purpose.

A transfer bump method (Japanese Unexamined Patent Publication No. 152147/1984) has been proposed as one means for joining lead terminals of a film carrier to electrode terminals of a semiconductor element. In this transfer bump method, Au metal protrusions (bumps) are formed on the insulating substrate at positions corresponding to the electrodes of the semiconductor element, and then the metal protrusions and the Sn-plated lead terminals of the film carrier are aligned. The metal protrusions on the insulating substrate are bonded to the lead terminals using the Au-Sn alloy by applying pressure and heating with a tool, and the metal protrusions are peeled off from the insulating substrate and transferred to the lead terminals. Next, the electrode terminals (aluminum) of the semiconductor element and the metal protrusions of the lead terminals are aligned, and a tool is used to apply pressure and heat.
The metal protrusion and the electrode terminal of the semiconductor element are bonded using an Au/Al alloy.

Conventionally, the lead of a transfer bump type film carrier has been constructed as shown in FIG. That is, apertures 4 are formed in the long resin film 1 in order to bond the semiconductor element 2 and the lead terminals 3 extending from the resin film 1. resin film 1
The lead terminals 3 extending from the opening had the same width in the area of the opening 4 (FIG. 1a). In this case, when aligning and transferring the metal protrusions formed on the board to the lead terminals 3, the extended lead terminals This makes it unclear in which region of the throat the metal protrusion should be transferred and bonded.

If the width of the lead terminal 3 is larger than the width of the metal protrusion 5, when aligning the electrode 6 of the semiconductor element 2 and the metal protrusion 5 transferred to the lead terminal 3, as shown in FIG. Since it is hidden behind the lead terminal 3, alignment becomes extremely difficult, leading to a decrease in bonding strength due to misalignment. Furthermore, if the width of the lead terminal 3 is smaller than the width of the metal protrusion 5, alignment in the direction perpendicular to the extending direction of the lead terminal 3 is relatively easy because the metal protrusion 5 protrudes from the lead terminal 3;
It became difficult to align the resin film 1 in the extending direction, and the distance A between the resin film 1 and the semiconductor element 2 became different in the vertical and horizontal directions (Fig. 1 c), and mechanical stress and thermal stress were applied to the resin film. In this case, since the lengths of the lead terminals 3 are different, the stress applied to the lead terminals 3 is also uneven in the vertical and horizontal directions, leading to breakage of the lead terminals 3. Furthermore, the difference in distance A causes unevenness in the heat dissipation from the lead terminal when bonding the metal protrusion and the electrode 6 of the semiconductor element, resulting in nonuniformity in the temperature distribution of the bonding tool. This resulted in a decrease in strength. This also applies to the configuration shown in FIG. 1b.

OBJECTS OF THE INVENTION In view of these conventional problems, it is an object of the present invention to provide a method for manufacturing a semiconductor device in which alignment is extremely easy and bonding strength is high.

Structure of the Invention The present invention makes the width of the film lead in the area where the metal protrusion is transferred and corresponds to the electrode of the semiconductor element smaller than that in other areas, thereby mounting the semiconductor element by the transfer bump method. When doing,
This greatly facilitates the alignment of the film lead, the metal protrusion, and the electrode of the semiconductor element, making it possible to manufacture a semiconductor device with high bonding strength.

DESCRIPTION OF EMBODIMENTS FIG. 2 shows the shape of a film lead that is an embodiment of the structure of the present invention.

Film lead 3 extending from resin film 1
The tip portion 11 is a region where the metal protrusion is transferred and corresponds to the electrode of the semiconductor element, and the width B of this portion 11 is formed smaller than the width A of the extended film lead 3. (Figure 1a). Further, the length C of the tip portion 11 of the film lead corresponds at least to the length of one side of the electrode of the semiconductor element, and also corresponds to the length D of the metal protrusion 13 in the extending direction of the film lead. It has dimensions. For example, the length is the same as the length of one side of the electrode of the semiconductor element, or it is shorter. On the other hand, the same applies to the metal protrusion 13, and the metal protrusion 13 formed on the substrate 12
It is the same size or shorter than the dimension D in the extending direction of the film lead (FIGS. 1b and 1c). Further, the width B of the tip portion 11 is smaller than the width of the metal protrusion 13.

In such a configuration, when aligning the metal protrusion and the film lead, it is sufficient that the metal protrusion 13 enters the tip 11 of the film lead.
At this time, since the tip portion 11 is smaller in width than the other regions and its length C is the same as or smaller than the dimension D of the metal protrusion 13, it can be aligned extremely easily, and This eliminates the possibility of poor alignment and instability of bonding strength due to this.

Next, the structure of the film lead of the second embodiment will be explained with reference to FIG. The length C' of the tip 11' of the film lead 3 is shorter than the width D' of the metal protrusion 13 (FIG. 2c). In such a configuration, for example, if the boundary 14 where the film lead 3 is narrowed is designed to have a dimension C' that corresponds to the central area of the metal protrusion 13, the alignment between the metal protrusion and the film lead can be made as follows. Since it is sufficient to align the film lead so that the boundary 14 is at the center of the metal protrusion 13, alignment is extremely easy and reliable.

Next, an embodiment of the entire process of the present invention will be described using FIG.

Film lead 3 extending from resin film 1
is formed into a beam shape by etching Cu foil, and is plated with Sn to a thickness of 0.4 μm. On the other hand, the substrate 12 for forming the metal protrusions 13 is an insulating substrate made of glass, ceramic, etc.
A metal film such as Pt, Pd, ITO, etc. or a conductive metal oxide film is formed, and on top of this, a plating mask pattern is formed in which holes are formed only in regions corresponding to the electrodes of the semiconductor element. SiO ₂ , Si ₃ An insulating film such as N ₄ or polyimide film is formed, and metal protrusions 13 are formed in the openings by electrolytic plating (FIG. 4a).

Next, the wide area of the film lead 20 and the metal protrusion 13 are aligned, and the bonding tool 30 is
The metal protrusions 13 are transferred and bonded to the wide area of the tip of the film lead using an alloy of Au and Sn, and the metal protrusions 13 are peeled off from the substrate 12 (fourth step). Figure b).

Next, the metal protrusions 13 transferred and bonded to the film lead 3 are aligned with the electrodes 6 of the semiconductor element 2. In this case, it is only necessary to align the wide area of the film lead 3 and the electrode. Good (Figure 4c). When the alignment is completed, the metal protrusion 13 is reliably aligned and present within the region on the electrode 6 of the semiconductor element 2. In this state, if pressure and heat are applied using the bonding tool 31, the metal protrusions are bonded with the Au-Al alloy, resulting in the state shown in FIG. 4d.

Effects of the Invention Since the width of the extended film lead is narrow only in the area where the metal protrusion is transferred, when aligning the metal protrusion with the film lead, the metal protrusion is aligned in the narrow area. This greatly facilitates positioning and reduces the time required for this step.

In addition, since alignment is performed based on the metal protrusion and the narrower end region of the film lead, the dimension A in FIG. Since the strength of the leads is not reduced, a highly reliable semiconductor device can be obtained.

Furthermore, since alignment is easy and can be carried out reliably, misalignment between the metal protrusion and the film lead does not occur. Therefore, a highly reliable semiconductor device with significantly stable bonding strength can be obtained.

[Brief explanation of drawings]

FIG. 1a is a schematic plan view of a conventional film lead, FIGS. 1b and c are schematic plan views showing the alignment of the lead, metal protrusion, and electrode of a semiconductor element, and FIGS. 2a and b are in accordance with the present invention. A plan view showing the alignment state of the film lead and the metal protrusion, Fig. 2c
3 is a schematic plan view of a film lead according to another embodiment of the present invention, and FIGS. 4 a to 4 d are sectional views showing the process of the transfer bump method using the present invention. be. 3...Film lead, 2...Semiconductor element, 6
... Electrode, 11 ... Tip region, 12 ... Substrate, 1
3...Metal protrusion.

Claims (1)

[Claims] 1. The width of the first region, which is the region where the metal protrusion of the film lead extending from the resin film is transferred and corresponds to the electrode of the semiconductor element, is smaller than the width of the other second region and the width of the metal protrusion. A method for manufacturing a semiconductor device, characterized in that the metal protrusion on the substrate is formed smaller than the first region, and the metal protrusion on the substrate is transferred and bonded to the first region, and then the metal protrusion is bonded to the electrode of the semiconductor element.