JP3286063B2 - 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. 5 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 two wafers to be processed while being supported by one 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, according to the present invention, semi-annular frame members each having two holding grooves formed on the inner peripheral surface thereof are rotatably combined at one end with each other. A frame that is formed in an annular shape similar to the outer periphery of the wafer to be held, and each peripheral edge is fitted into an annular holding groove formed by combining the holding grooves of both frame members in this frame. In this case, a plating rack having a structure in which a pair of wafers is held back to back with the respective surfaces to be plated facing each other is used, and this plating holding a pair of wafers is used. The rack is immersed in a plating solution in a plating tank, and in this immersion state, the plating solution is brought into fluid contact with the plating target surface of each wafer on the front side to perform plating.

According to the present invention, since two wafers can be processed simultaneously by one rack, the wafer 1
The amount of plating solution used per sheet can be greatly reduced, and the size of the apparatus per processing capacity 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.

In order to impart a flowing state of the plating solution to the wafer without spraying and supplying the plating solution, a method of stirring the plating solution in a plating tank is also possible. How to rotate,
It is more preferable that higher uniformity of the flow distribution of the plating solution on the plating target surface can be obtained.

According to the present invention, in the plating rack as described above, the tip of the electrode terminal is provided so as to protrude from the inner side wall of the holding groove, and when the peripheral portion of the wafer is fitted into the holding groove, the electrode terminal is provided. The resist film at the corresponding portion is scraped off at the tip of the wafer so that power can be supplied to the wafer.
This utilizes the structure of holding the wafer by fitting its peripheral edge to the holding groove, and as a result, it is indispensable for stable plating treatment and for wafers that have been required various devices in the past. Energization of the cathode can be easily and reliably ensured.

[0011]

An embodiment of the present invention will be described below.
As shown in FIGS. 1 and 2, a plating rack 1 according to the present embodiment is configured such that a rotational force transmitting unit 3 is connected to a frame 2 formed in an annular shape similar to the outer periphery of a wafer W to be held. ing.

The frame 2 is formed by connecting a pair of semi-annular frame members 5 and 5 having two holding grooves 4 and 4 on the inner peripheral surface thereof at one end thereof so as to be rotatable. , Wafer W
In order to mount and take out the camera, the camera can be rotated and opened as shown by imaginary lines in the figure. As shown in FIG. 3, the tip of the electrode terminal 6 for the cathode is slightly protruded from the inner wall of the holding groove 4, 4 of each frame member 5 so that the tip can be elastically protruded and retracted.

In order to hold the wafer W on the plating rack 1, first, the two frame members 5, 5 are opened as described above.
Therefore, the wafers W, W are sandwiched between the frame members 5, 5 with the surfaces to be plated facing each other back to back, and then the frame members 5, 5 are closed. Then, each wafer W is held by the frame 2 in a state where the respective peripheral edges are fitted to the holding grooves 4 and 4 of both the frame members 5 and 5 over the entire circumference. At this time, the peripheral edge of the wafer W is rubbed so that the tip of the electrode terminal 6 is pushed into the inner wall of the holding groove 4, and as a result, the resist film applied thereon is scraped off at the tip of the electrode terminal 6. Thus, a conduction state between the electrode terminal 6 and the wafer W is obtained.

The two wafers W thus held are
The back side of W is completely sealed with the plating solution, and when the rack 1 is immersed in the plating solution M in the plating tank 7 as shown in FIG. Alone can be selectively brought into contact with the plating solution M.

As shown in FIG. 4, the plating using the plating rack 1 proceeds while the plating rack 1 is immersed in the plating solution M in the plating tank 7 and gently rotated. In order to rotate the plating rack 1, a rotational force is transmitted from a drive system (not shown) via a rotational force transmitting unit 3, but a generally known mechanism can be used. And illustration is omitted.

Generally, the plating solution M needs to be heated, but in this example, indirect heating by a hot bath method is used. That is, the plating bath 7 is immersed in a hot bath 8 filled with the heating liquid L to heat the plating solution M in the plating bath 7.

[0017]

As described above, according to the present invention, two wafers can be processed simultaneously by one rack.
The amount of plating solution used per wafer can be greatly reduced, the size of the equipment per processing capacity can be reduced, and there is no need to supply the plating solution by jetting as in the past. The device elements such as the liquid supply mechanism can be greatly simplified.

[Brief description of the drawings]

FIG. 1 is a side view of a plating rack according to the present invention.

FIG. 2 is a sectional view taken along the line SA ₂ ─SA ₂ in FIG. 1;

FIG. 3 is a cross-sectional view showing a state in which electrode terminals are assembled into holding grooves of a frame member.

FIG. 4 is a sectional view showing a state of a plating process using the plating rack of FIG. 1;

FIG. 5 is a configuration diagram of a conventional plating system.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Plating rack 2 Frame 3 Rotational force transmitting part 4 Holding groove 5 Frame member 6 Electrode terminal 7 Plating tank M Plating solution W Wafer

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int. Cl. ⁷ , DB name) C25D 17/08 C25D 5/02 C25D 5/08 C25D 7/12

Claims (4)

(57) [Claims] 1. A semi-annular frame member having two holding grooves formed on an inner peripheral surface thereof in a wafer plating rack for holding a wafer in a state where a surface to be plated is selectively brought into contact with a plating solution. It has a frame formed in an annular shape similar to the outer periphery of the wafer to be held by being rotatably combined at one end of each other, and fitting the respective peripheral edges to the holding grooves of both frame members in the frame. A pair of wafers being held back-to-back with the surfaces to be plated facing each other. 2. A tip of an electrode terminal is provided on an inner side wall of a holding groove so as to protrude, and when a peripheral edge of a wafer is fitted into the holding groove, a resist of a corresponding portion is scraped off at the tip of the electrode terminal to form a wafer. Claim 1 wherein electricity can be supplied to
The plating rack as described. 3. A plating method for plating a wafer using the plating rack according to claim 1 or 2, wherein the plating rack holding a pair of wafers is plated in a plating tank. A plating method in which a plating solution is immersed in a solution and a plating solution is fluidly brought into contact with a surface to be plated of each wafer in this immersion state to perform plating. 4. The plating method according to claim 3, wherein the plating rack is rotated to give a flowing state of the plating solution to the wafer.