JPH0375394A - Plating equipment - Google Patents

Abstract

PURPOSE:To easily perform alignment of a pad on a wafer and the electrode of a plating equipment by equipping both the electrode allowed to abut against the pad and a pincher for holding the wafer to a tray, attaching and detaching this tray to/from a cup. CONSTITUTION:This equipment is constituted so that a wafer 3 is fitted to a tray 6 provided separately from a cup 1 and this tray 1 is provided to the upper edge of the cup 1. Therefore alignment of both an electrode 8a provided to the tray 6 and a pad 4 on the wafer 3 can be easily performed while viewing the positions thereof. Further when a plurality of trays 6 are prepared for the cup 1 and the successive wafer 5 is fitted to the other tray 6 while plating is progressed, plating work can be quickly restarted only by providing the fresh tray 6 to the cup 1. Therefore throughput can be enhanced and also generation of imperfect bump due to the imperfect contact of the electrode 8a and the pad 4 can be previously prevented.

Description

[Detailed Description of the Invention] [11 Requirements] An object of the present invention is to provide a plating device for plating bumps on a wafer for forming semiconductor devices, and to enable easy alignment of pads on the wafer and electrodes of the plating device. , a plating apparatus that places a wafer on the upper edge of a cup storing a plating solution, connects an electrode to a pad provided on the wafer, and sprays the plating solution onto the wafer to plate bumps on the wafer surface, A tray including an electrode that contacts a pad and a clamping device that holds a wafer with the electrode in contact with the pad is configured to be removably attached to the cup.

[Industrial Application Field] The present invention relates to a plating apparatus for plating bumps on wafers for forming semiconductor devices.

In recent years, wire bonding has been replaced by TA for wiring between chips and packages in the manufacturing process of semiconductor devices.
B (Tape AutoIlated Bondin
g) The wiring structure of the method has been put into practical use. In the TAB wiring structure, it is necessary to form bumps at predetermined positions on the substrate of the chip, and these bumps are usually formed by plating the wafer at predetermined positions with a stand or solder using a plating device.

[Prior Art] The outline of a conventional plating apparatus for forming gold bumps on a wafer will be explained with reference to FIG. 2 is provided, and both ends of the wire #12 are bent upwardly inside and outside the cup 1, respectively, to form an inner end 2a and an outer measuring end 2b. Further, the distance of 8 between the III ends of each electrode 2 is set in accordance with the distance between the pads 4 formed in advance on the wafer 3 to be plated.

To plate a bump with this plating apparatus, a pad 4 is formed in advance, and the surface of the wafer 3, on which bump formation positions are patterned with photoresist, is brought into contact with the inner side f12a of the electrode 2 against the pad 4, with the surface of the wafer 3 facing downward. After supporting the wafer 3 on the electrode 2, cover the cup 1 with a lid (not shown) to hold the wafer 3 in this state, and connect the negative l111 power terminal to the outer end 2b of the electrode 2. The positive power supply terminal is immersed in the plating solution la inside the cup 1. In this state, when the plating solution 1a is jetted onto the surface of the wafer 3 from the spout tube 5 inside the cup 1, the surface of the wafer 3 is formed into a predetermined shape based on the patterning by the photoresist. Bumps are plated at the locations.

[Problems to be Solved by the Invention] However, in the above plating apparatus, it is necessary to support the wafer 3 on the electrode 2 with the surface facing downward, and the wafer 3 supported on the electrode 2 and the upper edge of the cup are Since the gap between the wafer 3 and the wafer 3 is small, and the pad 4 has a small area, it is extremely troublesome to position the pad 4 on the surface of the wafer 3 so that it is in reliable contact with the inner end 2a of the electrode 2.
This caused a decrease in output. Furthermore, if the contact between the inner end 2a of the electrode 2 and the pad 4 is insufficient,
There are problems in that bumps of sufficient thickness cannot be plated, and the thicknesses of the bumps plated on various parts of the wafer 3 become uneven.

An object of the present invention is to provide a plating apparatus that can easily align pads on a wafer and electrodes of the plating apparatus.

"Means for Solving the Problems" FIG. 1 is an explanatory diagram of the principle of the present invention. That is, a wafer 3 is placed on the upper edge of a cup 1 in which a plating solution 1a is stored, and a pad 4 provided on the wafer 3 is The electrode 8a is connected to the wafer 3, and the plating solution 1a is spouted onto the wafer 3.
A plating device is configured to plate bumps on the surface. A tray 6 is configured to be removably attached to the cup 1, and includes an electrode 8a that contacts the pad 4, and a clamping device 16 that holds the wafer 3 in contact with the entire 'rrh electrode 8a. has been done.

[Function] The wafer 3 can be aligned with the electrode 8a of the tray 6 while checking the position of the pad 4 formed on its surface.
The tray 6 holding the wafer 3 is placed in the cup 1 by the clamping device 16.
The wafer 3 is placed on the upper edge of the cup 1 by attaching it to the upper edge.

[Example] Hereinafter, an example embodying the present invention will be described with reference to FIGS. 2 to 4. Note that the same components as those in the conventional example will be described with the same numbers.

The elongated tray 6 shown in FIGS. 2 and 3 has two mounting holes 7 with a diameter slightly smaller than that of the previous wafer 3, and ThN rods 8 are formed at three locations around the mounting holes 7. The tray 6 is penetrated so as to be movable in the thickness direction. Q! :h The tip of the scraper 8 is bent along the tray 6 and further bent toward the surface of the tray 6 to form an electrode 8a. The spacing between the pads 4a on the wafer 3 is set equal to the spacing between the pads 4 on the wafer 3.

The electrode rod 8 protruding from the back surface of the tray 6 passes through a support piece 9 extending from the tray 6, and a flange 10 is formed between the support piece 9 and the back surface of the tray.
A coil spring 11 is disposed between the tray 6 and the rear surface of the tray 6. The coil spring 11 uses the back surface of the tray 6 as a fulcrum to bias the flange 10 in the direction of the support piece 9, so when the wafer 3 is not attached, the flange 10 comes into contact with the support piece 9, and the electrode 8a is inserted into the mounting hole 7. It's starting to stand out.

In order to plate the wafer 3 with the bread 1 using such a tray 6 in the plating apparatus shown in FIG. Push up and place the wafer 3 between the i8a and the surface of the tray 6.
Ensure a gap of at least the thickness of
Wafer 3 is inserted between a and the surface of tray 6. Then, when the pad 4 on the wafer 3 is aligned with the electrode 8a and the pushing up of the electrode rod 8 is released, the electrode 8a comes into contact with the pad 4 as shown in FIG. At i8a, the wafer 3 is held in a pressed state around the attachment hole 7.

In this state, the tray 6 is turned over and placed on the upper edge of the cup 1 as shown in FIG. 4, and the lid 12 that holds the tray 6 on the cup 1 is covered. The connector 12 is provided with a connector 13 for connecting the electric rod 8 to a negative open power terminal, and is also provided with a gas ejection pipe 14 for ejecting N2 gas toward the surface of the wafer 3s. Inside the cup 1 is a net-shaped positive f! connected to the positive power terminal. 15 are soaked.

When the plating solution 1a is ejected from the ejection tube 5 toward the surface of the wafer 3 in this state, bumps are plated based on the patterning formed on the surface of the wafer 3.
The leakage of the plating 8N1a from the gap between the wafer 3 and the tray 6 to the back surface of the wafer 3 is caused by the N jetted out from the gas jetting pipe 14.
This can be suppressed by 2 gases.

As described above, in this plating apparatus, the wafer 3 is mounted on the tray 6 provided separately from the cup, and the wafer 3 is mounted on the tray 6 provided separately from the cup.
Since the electrodes 8a are installed on the upper edge of the cup 1, alignment of the @poles 8a provided on the tray 6 and the pads 4 on the wafer 3 can be easily performed while visually checking their positions. In addition, if multiple trays 6 are prepared for cup 1, if the subsequent wafer 3 is attached to another tray 6 while plating is in progress, plating can be performed immediately by simply installing the new tray 6 in cup 1. You can resume your work. Therefore, throughput can be improved, and occurrence of bump defects due to poor contact between the electrodes 8a and the pads 4 can be prevented.

[Effects of the Invention] As described in detail above, the present invention exhibits an excellent effect of easily aligning pads on a wafer and electrodes of a plating apparatus.

Schematic diagram, FIG. 5 is a schematic diagram of a conventional plating apparatus.

In the figure, 1 is a cup, 1a is a plating solution, 3 is a wafer, 4 is a pad, 6 is a tray, 8a is an electrode; 16 is a clamping device.

[Brief explanation of drawings]

Fig. 1 is a diagram explaining the principle of the present invention, Fig. 2 is a sectional view showing a tray according to an embodiment of the invention, Fig. 3 is a perspective view of the tray, and Fig. 4 is a schematic diagram of a plating apparatus equipped with the tray. 1st
Figure 2: A cross-sectional view showing a tray according to an embodiment of the present invention Figure 3: Schematic diagram showing a mw plating apparatus according to the present invention Figure 3: Perspective view of a tray Figure 5: Conventional plating apparatus Schematic diagram of the date

Claims (1)

[Claims] 1. A wafer (3) is placed on the upper edge of a cup (1) storing a plating solution (1a), and an electrode (Ba) is attached to a pad (4) provided on the wafer (3). This is a plating device for plating bumps on the surface of a wafer (3) by spouting a plating solution (1a) onto the wafer (3), and comprising: an electrode (8a) in contact with a pad (4); 8
A tray (6) equipped with a clamping device (16) that holds the wafer (3) in a state where the wafer (3) is in contact with the pad (4) is detachable from the cup (1). plating equipment.