JP3286064B2 - Wafer plating rack and plating method using the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a technique for plating a semiconductor wafer.

[0002]

2. Description of the Related Art When plating a wafer, such as bump plating, it is an important factor to selectively bring only the surface to be plated into contact with a plating solution. Therefore, conventionally, a plating system having a basic structure as shown in FIG. 6 is generally used. In this system, a cup-shaped jet tank 21 which is also a support means for a wafer W is provided in a plating tank 20, and the upper end of the jet tank 21 is covered with the wafer W with its surface to be plated facing down. In this state, the plating solution is supplied into the spray tank 21 from the heating tank 22 through the circulation pipe 23 in a spray form. The plating solution M supplied to the spray tank 21 is supplied to the wafer W A flow spreading to the periphery while contacting the surface to be plated is formed and flows out to the plating tank 20 (for example, Japanese Utility Model Publication No. 58-8774, Japanese Utility Model Application Laid-Open No. 3-19).
No. 70, Japanese Utility Model Laid-Open No. 4-44371, etc.).

[0003] As can be seen, in the conventional system, only one wafer can be processed per injection tank. This is a processing efficiency issue,
In particular, there is a problem that a large amount of plating solution is used per wafer, and a large number of spray tanks must be provided in a horizontal direction in order to efficiently process a large amount of wafers. However, there is also a problem that the size of the device increases.

Further, in the conventional system, since it is necessary to jet and supply a plating solution into an injection tank, equipment elements such as a plating tank and a plating solution supply mechanism become complicated.
This is another factor in increasing the size of the entire apparatus, and also requires a fixed arrangement of the apparatus, which hinders efficient use of the factory space.

[0005]

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to enable a plurality of wafers to be processed while being supported by a single supporting means, specifically, a rack, so that plating per wafer can be performed. It is an object of the present invention to reduce the amount of solution used, reduce the size of the entire apparatus, and simplify the apparatus elements such as a plating tank and a plating solution supply mechanism.

[0006]

For this purpose, the present invention provides an annular support member having a support surface for supporting a peripheral portion of a wafer to be held at a constant width, and this support member. Plating rack having a structure in which a plurality of holding units each configured by a sealing mechanism for sealing the back surface of a wafer supported by a plating solution from a plating solution are supported in a multi-stage state by a plurality of columns via the periphery of each supporting member. This plating rack holding a number of wafers corresponding to the number of holding units is immersed in the plating solution in the plating tank, and in this immersion state, the plating solution is applied to the surface of the wafer of each holding unit. The plating is applied by fluid contact.

According to the present invention, a plurality of wafers can be processed simultaneously by a single supporting means, that is, a rack, so that the amount of plating solution used per wafer can be greatly reduced and the processing capacity can be reduced. Device size can be reduced.

Further, according to the present invention, the plating solution is brought into contact with the wafer while the plating rack is immersed in the plating solution in the plating tank. Therefore, it is possible to greatly simplify equipment elements such as a plating tank and a plating solution supply mechanism.

[0009]

An embodiment of the present invention will be described below.
As shown in FIGS. 1 to 3, the plating rack 1 according to the present embodiment has a plurality of columns 4, 2,.
The three holding units 3 (3a, 3b, 3c) are supported in three steps at a constant interval.

Each holding unit 3 has a structure in which a seal mechanism 5 is combined with an annular support member 4 having a support surface 4f for supporting the peripheral portion of the wafer W to be held with a width of about 2 to 3 mm. I have.

On the support surface 4f of the support member 4, a plurality of electrode terminals 6 for the cathode are formed so that the tips thereof slightly protrude at a plurality of positions, and when the wafer W is pressed against the support surface 4f as described later. The resist film on the surface of the wafer W is broken at the tip of each electrode terminal 6 so that the cathode W can be energized to the wafer W.

An electrode unit as shown in FIG. 4 can be used for the electrode terminal 6. This electrode unit has an electrode needle 6p formed in an elongated plate shape as a whole, a mounting hole 7p for fitting the electrode needle 6p in a state of being inclined forward and upward, and a screwing hole for connecting a power supply. The electrode block 7 has an elongated rectangular rod-shaped electrode block 7n and an electrode box for tightly accommodating the electrode block 7. The electrode box includes a box body 8, a lid 9 and a packing 10.
The lid 9 is provided with a projection 9d having an opening 9w so that the tip of the electrode needle 6p mounted in the mounting hole 7p of the electrode block 7 can be exposed obliquely forward from the opening 9w. Have been.

The seal mechanism 5 has a concave portion 11r having a spread size substantially corresponding to the outer peripheral size of the support member 4, and has a lower end portion connected to the cover member 11 connected to the support member 4 and a concave portion 11r of the cover member 11. The air bag 12 is inflated by compressed air supplied through a supply / discharge path 13 provided in the cover member 11 (the figure shows an inflated state). ), The periphery of the wafer W is covered by the supporting surface 4f of the supporting member 4 while covering the back surface of the wafer W on the supporting member 4 in a liquid-tight manner
To give liquid-tightness to the peripheral portion.

Each wafer W held by each of the holding units 3a, 3b, 3c requires an anode electrode corresponding to the wafer W. In the present embodiment, these are incorporated in the plating rack 1 in advance. Specifically, an anode electrode 14a is provided at the lower end of the plating rack 1 for the lowermost wafer W, and the upper two wafers W are fixed to the cover members 11 of the adjacent holding units 3a and 3b, respectively. The corresponding anode electrodes 14b and 14c correspond to each other.

As shown in FIG. 5, the plating process using the plating rack 1 is performed by immersing the plating rack 1 in a plating solution M in a plating tank 15 and then plating the plating solution M in this state.
With appropriate stirring. As a mechanism for stirring the plating solution M, a generally known mechanism can be used, and the description and illustration thereof are omitted.

[0016]

As described above, according to the present invention, a single rack can simultaneously process a plurality of wafers, so that the amount of plating solution used per wafer can be greatly reduced, and the apparatus per processing capacity can be reduced. Since the size can be reduced and there is no need to perform the conventional jetting supply of the plating solution, the device elements such as the plating tank and the plating solution supply mechanism can be greatly simplified.

[Brief description of the drawings]

FIG. 1 is a side view including a partial cross section of a plating rack according to the present invention.

Figure 2 is a plan view seen from the arrow A ₂ direction in FIG. 1.

Figure 3 is a bottom view viewed from arrow A ₃ direction in FIG.

FIG. 4 is an exploded perspective view of an electrode unit for an electrode terminal.

FIG. 5 is an explanatory view showing a state of a plating process using a plating rack according to the present invention.

FIG. 6 is a configuration diagram of a conventional plating system.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Plating rack 2 Prop 3 Holding unit 4 Support member 4f Support surface 5 Seal mechanism 11 Cover member 12 Air bag 15 Plating tank M Plating solution W Wafer

Claims (3)

(57) [Claims] 1. A plating rack for holding a wafer in a state where a surface to be plated is selectively brought into contact with a plating solution, the ring having a support surface for supporting a peripheral portion of the wafer to be held with a constant width. The support member and a plurality of holding units including a sealing mechanism for sealing the back surface of the wafer supported by the support member from the plating solution are supported in a multi-stage state by a plurality of columns via the periphery of each support member. A plating rack comprising: 2. A sealing mechanism comprising an air bag which is inflated by supply of a compressed gas, and a cover member which sandwiches the air bag between the air bag and a support member. 2. The plating rack according to claim 1, wherein the plating rack covers the back surface of the upper wafer and presses the peripheral edge of the wafer against the supporting surface of the supporting member. 3. A plating method for plating a wafer using the plating rack according to claim 1 or 2, wherein the plating rack in which each holding unit holds a wafer is a plating solution in a plating tank. A plating method in which a plating solution is fluidly brought into contact with the surface of the wafer of each holding unit in this immersed state to perform plating.