JPH0586498A - Plating device - Google Patents

Abstract

PURPOSE:To precisely control a plating thickness by surely controlling the current flowing through a material to be plated. CONSTITUTION:Fixing means consisting of cathode pins 14a, 14b, 14c, retaining springs 15a, 15b, 15c, and a retaining ring 16 are provided in a cassette 12. The resist film on the surface of an IC wafer 1 is punctured by such fixing means and is held into pressurized contact with the cathode pins 14a, 14b, 14c and the IC wafer 1 is fixed in this state. The cassette 13 is held by cassette insertion grooves 17a, 17b of a cap 6. The contact state of the IC wafer and the cathode pins can be visually checked before plating is executed by holding the cassette in the prescribed position within a liquid tank 2. The respective cathode pins are coated with flexible tubes so as not to be stuck with the plating.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a plating apparatus for performing projection plating on the surface of a material to be plated, and more particularly to a plating apparatus having an improved mechanism for mounting the material to be plated in a liquid tank of a jet type electroplating apparatus.

[0002]

2. Description of the Related Art Conventionally, a jet type electroplating apparatus as shown in FIG. 4 (A) has been used for performing precise projection plating (bump plating) on an integrated circuit substrate (IC wafer) or the like. It was Here, an IC wafer 1 as a material (work) to be plated is held by a work holder 3 at a predetermined position in a liquid tank 2 containing a plating solution with its surface facing downward. When the plating liquid 5 is supplied to the jet cylinder 4 in the liquid tank 2 at a constant flow rate, the plating liquid 5 is supplied to the work holder 3
It contacts the surface of the IC wafer 1 held above. The lid 6 of the liquid tank 2 is provided with a retainer 7, and the lid 6 of the liquid tank 2 is provided.
The IC wafer 1 is pressed against the cathode pins 8a and 8b by the retainer 7 in the closed state. Thus IC
The wafer 1 is used as one of the electrodes to be electrically connected to the anode mesh 9 in the jet cylinder 4 and electroplated with the plating solution supplied to the jet cylinder 4 at a constant flow rate by the pump 10. There is.

By the way, bump plating must be stably formed on the surface of the IC wafer 1 with a uniform plating thickness. For that purpose, it is necessary to control the flow rate of the plating solution which comes into contact with the surface of the IC wafer 1 on which the resist film 11 is formed, as enlargedly shown in FIG. Therefore, the amount of the plating solution sent to the jet cylinder 4 is controlled by the pump 10
At the same time, the plating solution in contact with the IC wafer 1 is made to overflow from the peripheral portion of the upper portion of the jet tube 4 and returned to the solution tank 2. Further, the cathode pins 8a and 8b are insulated by a coating layer 12 such as a Teflon coating in order to prevent the plating solution from being excessively attached.

[0004]

As described above, the IC wafer 1 fixed by the work holder 3 is brought into contact with the plating solution using the IC wafer 1 itself as a negative electrode, and the surface of the IC wafer 1 is plated with protrusions. .. In that case, since the resist film 11 is formed on the surface of the IC wafer 1, the cathode pins 8a and 8b have sharp tip portions, and the resist film 11 is formed when the lid 6 of the liquid tank 2 is closed. And the cathode pins 8a and 8b come into contact with the IC wafer 1 and are energized.

However, in the conventional plating apparatus, once the lid 6 of the liquid tank 2 is closed, it cannot be visually inspected whether the tips of the cathode pins 8a, 8b are in contact with the IC wafer 1 reliably. Therefore, when electricity is applied between the cathode pins 8a, 8b and the anode mesh 9 in the jet cylinder 4, I
It was difficult to determine whether the C wafer 1 itself was acting as a negative electrode, or whether it was only energized by the plating solution near the tips of the cathode pins 8a, 8b.

Therefore, in the structure of the conventional plating apparatus, depending on the contact state between the cathode pins 8a, 8b and the IC wafer 1, even if only the flow rate of the plating solution is controlled, it is possible to reliably control the energization of the material to be plated. Absent. For this reason, there has been a problem in that the surface of the material to be plated cannot be precisely plated with protrusions.

In addition, the insulating layer is coated with the coating layer 12 except for the tip portions of the cathode pins 8a, 8b, but the insulating property is deteriorated by repeated breakage of the Teflon coating. When the plating adheres to the cathode pins 8a and 8b, the contact with the IC wafer 1 becomes insufficient, and especially when using a plurality of pins, bump plating on the material to be plated has a uniform plating thickness. There was also the problem that it would not be formed.

The present invention has been made in view of the above points, and it is possible to reliably control the current flowing through the material to be plated,
An object of the present invention is to provide a plating apparatus capable of precisely controlling the plating thickness.

Another object of the present invention is to provide a plating apparatus in which the plating does not adhere to the pins that come into contact with the material to be plated.

[0010]

In the present invention, in order to solve the above-mentioned problems, a material to be plated is brought into contact with a plating solution as an electrode in a solution tank containing the plating solution, and projection plating is applied to the surface thereof. In the plating apparatus for applying, a plate-shaped member that includes a plurality of pins that come into contact with a conductor portion of the material to be plated and is detachably held at a predetermined position in the liquid tank, and a plurality of conductor portions of the material to be plated While pressed against the pin of
Fixing means for fixing the plated material to the plate-shaped member,
There is provided a plating apparatus having:

[0011]

The conductor portion of the material to be plated is fixed to the plate member by the fixing means while being pressed against the plurality of pins.
After that, the plate-shaped member is held at a predetermined position in the liquid tank. That is, the contact state between the pin and the material to be plated can be visually confirmed before plating, and therefore the current flowing through the material to be plated can be reliably controlled.

Further, if each pin of the plate member is covered with a flexible tube, plating does not adhere to the pin.
Moreover, by using a transparent tube, there is no obstacle in visually observing the contact state of the pin with the plated material.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 shows a schematic configuration of a liquid tank portion of the plating apparatus of the present invention. IC held at a predetermined position in the liquid tank 2
The wafer 1 is supported by a cassette 13 composed of a plate-shaped member. In this respect, this plating apparatus is very different from the conventional one. The plating liquid is supplied to the jet cylinder 4 at a constant flow rate, and the IC wafer 1 is used as one electrode to be electrically connected to the anode mesh 9 in the jet cylinder 4. Therefore, the basic structure for electroplating the IC wafer 1 as the material to be plated is the same as that of the conventional apparatus shown in FIG. 4 (A), and corresponding parts are designated by the same reference numerals.

A cassette 13 for supporting the IC wafer 1.
Is provided with three cathode pins 14a, 14b, 14c (however, the cathode pin 14c is not shown in the drawing) on the surface of the jet cylinder 4 facing the anode mesh 9, and the IC
The wafer 1 is pressed through the pressing ring 16 to the pressing springs 15a, 15b,
The cathode pin 14a, 14b, 14c is pressed and fixed from above by 15c. That is, these cathode pins 14
The a, 14b, and 14c are configured to contact the conductor portion of the IC wafer 1 to make electrical connection, and to be electrically connected to the anode mesh 9 in the jet cylinder 4 at a predetermined current value.

On the lower surface of the lid 6 of the liquid tank 2, two ejection plates 18 having cassette insertion grooves 17a, 17b parallel to each other are formed.
a and 18b are provided. As shown in FIG. 2, a hole 13 a that is slightly larger than the diameter of the IC wafer 1 is formed in a substantially central portion of the cassette 13. The IC wafer 1 is fitted therein together with the pressing ring 16, and the three pressing springs 15a, 15b, 15c are rotated to fix the pressing ring 16 in the hole 13a, so that the IC wafer 1 is almost in the central portion of the cassette 13. Fixed in.

After fixing the IC wafer 1, the cassette 13 is inserted into the cassette insertion grooves 17a, 17b of the protruding plates 18a, 18b of the lid 6 with the cathode pins 14a, 14b, 14c side down. Therefore, when the lid 6 is closed at the upper part of the liquid tank 2, the cassette 13 is held at a predetermined position in the liquid tank 2,
The IC wafer 1 fixed there comes into contact with the plating solution jetted from the jet cylinder 4 of the liquid tank 2.

FIG. 3A is a sectional view of the cassette, showing the IC wafer 1 fixed to the cassette 13. Further, FIG. 3B is an enlarged view of a part of FIG. 3A and shows a fixing means provided in the cassette 13.

The cassette 13 has cathode pins 14a, 14b, 14 covered with a flexible tube 19 made of Teflon.
c is fixed by studs 20a, 20b, 20c. As shown in FIG. 3B, for example, the flexible tube 1
9 is a transparent body, and the tip opening is a cathode pin 14
It has a length matching the tip portion of b. Cathode pin 1
4b is bent into a U shape, and the sharply formed tip portion faces the hole 13a from one surface side of the cassette 13 and slightly enters from the surface of the cassette 13. Further, a pressing spring 15 pivotally attached to the same stud 20b is provided on the opposite surface of the cassette 13 so as to face the hole 13a. Reference numeral 21 is a screw hole for fixing the cathode pin fitted from the side surface of the stud 20b.

A power supply for energizing the plating apparatus is arranged outside the liquid tank 2. Although not shown here, the lower surface of the lid 6 has a cassette 13
The negative electrodes reaching the positions corresponding to the studs 20a, 20b, 20c of the power supply are arranged, and when the cassette 13 is inserted into the cassette insertion grooves 17a, 17b, the negative electrodes of the power supply are connected to the cathode pins 14a, 14b via the lid 6. , 14c so as to be electrically connected to the upper ends thereof. Further, the anode mesh 9 is provided with a lead portion led out to the upper end portion of the jet cylinder 4, and when the lid 6 of the liquid tank 2 is closed, the positive electrode disposed at the lower end portion of the ejection plate 18a is an anode. The mesh 9 is electrically connected.

With the IC wafer fixing means thus constructed, the state in which the IC wafer 1 is fixed to the cassette 13 can be easily visually confirmed before the cassette 13 is mounted in the plating apparatus shown in FIG. Therefore, after that, the cassette 13 is inserted into the cassette insertion groove 17a,
Before inserting into 17b, holding in place in the bath 2 and plating, the contact state between the cathode pins 14a, 14b, 14c and the IC wafer 1 can be reliably checked, and therefore the current flowing through the plated material Can be reliably controlled.

Further, each cathode pin 14a of the cassette 13 is
Since 14b and 14c are respectively covered with the flexible tube 19, extra plating does not adhere to the cathode pins 14a, 14b and 14c, so that bump plating on each surface of the IC wafer 1 is stabilized with a uniform plating thickness. Can be formed. Moreover, the use of a transparent tube as the flexible tube 19 does not hinder the visual observation of the contact state. Further, since the flexible tube 19 covers the cathode pins 14a, 14b, 14c with a length corresponding to the tips of the cathode pins 14a, 14b, 14c, the cathode pins 14a, 14b, 14c penetrate the resist film. Flexible tube 19 in a state of being in contact with the IC wafer 1
Since the opening of the tip of the plate comes into close contact with the IC wafer 1, the intrusion of the plating solution is reliably prevented.

The cassette 13 is placed at a predetermined position in the liquid tank 2.
In order to hold the
b is provided, and the cassette 1 is inserted in the cassette insertion groove 17a, 17b.
It does not have to be a configuration in which 3 is inserted. However, the method of slidingly inserting into the lid 6 as shown in the above embodiment is easier to prevent the plating solution from being contaminated as compared with the method of directly fixing the cassette 13 in the liquid tank 2. Thus, it becomes easy to automate the attaching / detaching process of the cassette 13.

In the above embodiment, the IC ring 1 is fixed to the flexible tube 19 by using the pressing ring 16 and the three pressing springs 15a, 15b and 15c. Instead of such fixing means, A structure may be adopted in which the IC wafer 1 is fixed to the cassette 13 only by inserting it into a predetermined cassette insertion groove.

[0024]

As described above, according to the present invention, the current flowing through the material to be plated can be surely controlled and the plating thickness can be precisely controlled. Further, since the plating is prevented from adhering to the pins that come into contact with the material to be plated, bump plating can be formed on the material to be plated with a uniform plating thickness.

[Brief description of drawings]

FIG. 1 is a diagram showing a schematic configuration of a liquid tank portion of a plating apparatus of the present invention.

FIG. 2 is a perspective view showing a configuration of a cassette for fixing an IC wafer.

FIG. 3A is a sectional view of a cassette, and FIG. 3B is an enlarged sectional view of a part of fixing means provided in the cassette.

FIG. 4A is a view showing a conventional jet type electroplating apparatus, and FIG. 4B is an enlarged view showing a tip portion of a cathode pin.

[Explanation of symbols]

 1 IC wafer 2 Liquid tank 13 Cassette 14a, 14b, 14c Cathode pin 15a, 15b, 15c Holding spring 16 Holding ring

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Office reference number FI technical display location C25D 17/08 A 7179-4K

Claims (2)

[Claims] 1. A plating apparatus for contacting a plating solution as an electrode with a plating solution in a liquid tank containing the plating solution and performing projection plating on the surface of the plating solution, the method being in contact with a conductor portion of the plating material. A plate-shaped member that includes a plurality of pins and is detachably held at a predetermined position in the liquid tank; and a conductor portion of the material to be plated is pressed against the plurality of pins, A plating device, comprising: a fixing unit that fixes the plate member. 2. The plating apparatus according to claim 1, wherein each pin of the plate-shaped member is covered with a flexible tube.