JPS6085545A - Method for formation of bump electrode for semiconductor element - Google Patents

Abstract

PURPOSE:To attach a bump electrode to a non-defective element only by a method wherein, after a bump electrode formed at the position on a substrate corresponding to the junction pad of a semiconductor element has been temporarily transferred to the tip of a group of leads, the bump electrode and the element pad are transferred to an element in a coincided form. CONSTITUTION:A metal film 7 is printed on a glass plate 7, a glass mask 9 is provided, and an Au protrusion 11 is formed on a window 10 by performing a plating. A metal fine wire 12 of 50mum in wire width is provided on a substrate in the same pitch as the protrusion 11, and an Sn plating is performed on the surface. The fine wire 12 group and the metal protrusion 11 group are positioned, heat and pressure are applied to them using a tool 13, and they are transferred and connected in a collective manner. Then, a positioning is performed on the transferred fine wire 12 and the metal electrode 15 of a semiconductor element 14, heat and pressure are applied to the above, a supersonic vibration 16 is added, and when the fine wire 12, the metal protrusion 11, and the electrode 15 of the element 14 are simultaneous connected in a collective manner, a metal protrusion only is left on the electrode 15 of the element. As a metal protrusion is provided on the non-defective element only, wastefullness can be removed.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a method for forming a protruding electrode on a semiconductor element, which involves forming a metal protrusion on an electrode on a semiconductor element.

Structure of a conventional example and its problems A conventional method of forming a metal protrusion electrode on an electrode on a semiconductor element will be explained with reference to FIG.

Generally, there is h(l wiring 2 on the Si02 film 1, and a protective film 3 on top of it. Thousands of Cr+Ti etc. are placed on the Ae pallet part 4 to increase the adhesion with the A(?). Additionally, several thousand Cu and Pd are deposited to prevent the diffusion of Au, which is the protrusion material.

These are called barrier metal layers 5. After that, several tens of μ7n
The metal protrusions 6 are formed by plating with Au or solder.

In conventional methods for forming metal protrusions, completed semiconductor device wafers undergo additional processes such as vapor deposition, photolithography, and plating. For this reason, when forming the metal protrusions 6, there is a risk that a good semiconductor element may become defective, leading to a decrease in yield.In addition, since this method of forming metal protrusions is a processing step for each wafer, the wafer Metal protrusions 6 are formed on the electrodes regardless of whether the semiconductor elements inside are good or defective, resulting in a very inefficient processing process in low-yield semiconductor devices. is a method for forming protruding electrodes on semiconductor devices, which is less likely to cause defects in good semiconductor devices during formation.
No protruding electrodes are formed on defective semiconductor elements;
This invention provides a method for forming protruding electrodes on electrodes of only non-defective semiconductor elements.Structure of the InventionIn order to achieve this object, the present invention provides a method for forming protruding electrodes on electrodes of only non-defective semiconductor elements. a step of temporarily transferring the protruding electrodes to the tips of a group of leads, and aligning the protruding electrodes of the group of lead tips with a bonding pad of a semiconductor element and applying heat and pressure to transfer and bond the protruding electrodes to the semiconductor element. Description of an Embodiment An embodiment of the present invention will be described with reference to FIGS. 2 to 8.

The same parts as in FIG. 1 are given the same numbers. First, a method for creating a substrate on which only metal protrusions are formed and a method for forming metal protrusions will be described.

In FIGS. 2 and 3, a metal film 8 is formed as a plating electrode on a glass plate by vapor deposition or printing. Further, a glass film 9 is fired on top of the glass film 9 for use in plating, and windows 10 for plating growth are formed by etching the glass film 9 at positions corresponding to the electrodes of the semiconductor element. Au plating is applied to this board, and Au protrusion 1 is placed on window 1o.
form 1.

The metal protrusions 11 can be similarly formed by using ceramics, Si, or the like instead of the glass plate 7.

Next, as shown in FIG.
1 is joined. The thin metal wires 12 have the same pitch as the metal protrusions 11 formed on the substrate, have a line width of about 50 .mu.z, and have their surfaces plated with Sn.

First, as shown in FIGS. 5 and 6, after aligning the 12 groups of thin metal wires and the 11 groups of metal projections on the substrate, the heating tool 13
By applying heat and pressure, the 11 groups of metal protrusions are simultaneously transferred and bonded to the 12 groups of thin metal wires.

Next, as shown in FIG.
Join the group. Since the metal protrusions 11 groups are formed on the substrate at positions corresponding to the metal electrodes 15 groups on the semiconductor element 14, they also maintain the positions corresponding to the metal electrodes 15 groups even after being transferred to the metal thin wires 12 groups. After aligning the metal protrusions 11 on the 12 groups of thin metal wires and the 15 groups of metal electrodes on the semiconductor element 14, they are heated and pressurized by the heating tool 13.
12 groups of thin metal wires, 11 metal protrusions. Three groups of metal electrodes 16 on the semiconductor element 14 are bonded together at the same time. After joining the three members, pressure is continued by the heating tool, and ultrasonic vibrations 16 are further applied to the heating tool 13. Ultrasonic vibration 16
is transmitted to the junction of the three.

As shown in FIG. 8, the metal protrusion 11 and the thin metal wire 12 are bonded using an Au/Sn alloy.
Since the Au%n alloy is relatively brittle, it is destroyed by the ultrasonic vibration 16 and the metal protrusion 11 and the metal wire 12 are separated. As a result, only the metal protrusion 11 remains on the metal electrode 15 on the semiconductor element 14.

The thin metal wire 12, which serves as a medium for transferring the metal protrusions 11 from the metal protrusion forming substrate to the metal electrode 16 on the semiconductor element 14, can be used many times until the Sn plating on the surface disappears. Metal protrusions can also be formed on the metal protrusion-forming substrate by plating it again after use. Effects of the Invention In the method of forming metal protrusions on electrodes on a semiconductor element according to the present invention, metal protrusions are formed on the semiconductor element by vapor deposition, photolithography, etc. .

Processing such as plating is not required, preventing a drop in yield.

In addition, since metal protrusions can be formed by selecting only good semiconductor elements, there is no need to form metal protrusions on defective semiconductor elements, and metal protrusions can be formed efficiently even on low-yield semiconductor element wafers. It has the advantage of being able to perform various functions, and is of great industrial value.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view of a metal protrusion formed by a conventional method, FIG. 2 is a cross-sectional view of a metal protrusion formed on a glass substrate according to the present invention, and FIG. 3 is a cross-sectional view of a metal protrusion formed on a glass substrate and heated by the present invention Figure 0 is a side view showing the positional relationship of the tools. Figure 0 is a side view of a thin metal wire and a metal protrusion bonded to each other. Figure 7 is a side view of a thin metal wire and a metal protrusion bonded to each other. , a side view when ultrasonic vibration is applied, and FIG. 8 is a side view in which the thin metal wire and the metal protrusion are separated and the metal protrusion is formed on the electrode on the semiconductor element. 1...SiO2 film, 2...he electrode,
3...protective film, 4...h (l pad, 6...) rear metal layer, 6...metal protrusion, 7... ...Glass plate, 8...Metal film, 9...Glass film, 10...7 Window for tree growth, 11...Au protrusion, 12 ...
...Thin metal wire, 13...Heating tool, 1-4.
... Semiconductor element, 15 ... Metal electrode, 1
6... Ultrasonic vibration. Name of agent: Patent attorney Toshio Nakao and 1 other person @3
Figure 4 Figure I2 Figure 5 Figure 6 Figure 7 Figure 7

Claims (1)

[Claims] (1) Temporary transfer of protruding electrodes formed on the substrate at positions corresponding to the bonding pads of the semiconductor element to the tips of a group of leads, and bonding of the protruding electrodes at the tips of the group of IJ + leads and the semiconductor element. Match the pads to heat/
Pressure is applied to transfer and bond the protruding electrode to the semiconductor element,
A method for forming protruding electrodes on a semiconductor element, comprising the step of separating the lead group from the protruding electrodes. EI IJ- lead is tin-plated, the protruding electrode is gold, and the bonding pad is a metal whose main component is aluminum.The protruding electrode temporarily transferred to the tip of the lead is bonded by heating and applying ultrasonic waves. 2. The method of forming a protruding electrode on a semiconductor element according to claim 1, wherein the lead is bonded to a pad, and then the bonded portion is heated to separate the lead from the protruding electrode.