JP2570489B2 - Jet plating equipment - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a jet plating apparatus for spraying an electroplating solution onto an object such as a semiconductor wafer to electroplate the object.

[Conventional technology]

Conventionally, when performing electroplating on an object to be plated such as a semiconductor wafer, the object to be plated is arranged at the upper end of the cylindrical cell, and an anode is arranged at a lower part in the cylindrical cell. There is known a jet plating method in which an electroplating solution is blown up into the inside, and the lower surface is electroplated while the plating solution is sprayed on the lower surface of the object to be plated. Is effective when the bump electrodes are formed by raising the thickness to about 50 μm.

Conventionally, such a jet plating apparatus as shown in FIG. 2 has been used. That is, in the jet plating apparatus a shown in FIG. 2, a cylindrical cell c is disposed in a cylindrical cover b, and a plating step e is formed on a ring-shaped step d formed at an upper inner peripheral edge of the cell c. Is placed so as to close the upper end opening of the cell c, an anode f is arranged in the lower part of the cell c, and a plating solution jetting pipe g is connected to the lower end of the cell c. A plurality of plating solution discharge ports h are formed in the vicinity of the lower side of the step d, and the plating solution in the plating solution storage tank i ejects the plating solution by the operation of a pump (not shown). g is sprayed into the cell c from g, and plating is performed while spraying a plating solution on the lower surface of the workpiece e. In this case, the plating solution sprayed on the plating object e flows into the cover b from the plating solution discharge port h, and is returned to the plating solution storage tank i through the collecting pipe j communicating with the inside of the cover b. It has become.

[Problems to be solved by the invention]

However, the conventional jet plating apparatus described above has the following problems. That is, during the plating operation, gas or slime is generated from the anode, and the gas or slime often accompanies the object to be plated accompanying the jet of the plating solution, and as a result, a partial plating state is caused. In addition, defects such as uneven plating, uneven plating film thickness, adhesion of foreign matter, and roughening occurred. Further, in order to prevent such a gas from adhering, for example, when forming a bump electrode on a semiconductor wafer, the jet flow rate is increased to prevent gas generated at the anode from staying on the plating surface of the object to be plated. However, there is a problem that the shape of the bump becomes poor when the jet flow rate is increased, and the problem of the anode slime adhering to the surface to be plated cannot be sufficiently solved even if the jet flow rate is increased. .

The present invention has been made in view of the above circumstances, and prevents gas or slime generated at an anode from adhering to a plating object, thereby preventing plating defects. It is an object of the present invention to provide a jet plating apparatus that is prevented from staying on the surface.

[Means for solving the problem]

In order to achieve the above object, the present invention arranges an object to be plated at an upper end portion of a cylindrical cell disposed in a bottomed cylindrical cover, and arranges an anode at a lower portion in the cylindrical cell, In a jet plating apparatus for spraying an electroplating solution into the cylindrical cell and electroplating the lower surface while spraying a plating solution on the lower surface of the object to be plated, the inside of the cell is vertically moved into the cylindrical cell. A diaphragm having a large number of micropores is provided so as to partition, and an upper jet chamber and a lower anode chamber communicating with each other through the micropores of the diaphragm are formed in the cylindrical cell, and an upper end of the jet chamber is formed. An object to be plated, a jet pipe for jetting a plating solution into the jet chamber, and a plating solution discharge port for communicating the jet chamber with the inside of the cover in the tubular cell, With the anode in the room,
An introduction pipe for introducing the same plating solution as the plating solution was provided in the anode chamber, and a plating solution outlet communicating the anode chamber and the inside of the cover was formed. A plating solution collection pipe was connected to the cover. This is a jet type plating apparatus characterized by the above.

[Action]

According to the jet plating apparatus of the present invention, a diaphragm having a large number of micropores is disposed in a cylindrical cell disposed in a bottomed cylindrical cover so as to partition the cell up and down. An upper jet chamber and a lower anode chamber communicating with each other through the fine holes are formed in the cylindrical cell, and an object to be plated is arranged at an upper end of the jet chamber, and an anode is arranged in the anode chamber. As a result, the gas and slime generated from the anode are blocked from flowing into the jet chamber by the diaphragm located above the anode, so that the gas and slime do not adhere to the object to be plated. Insufficient plating due to the adherence of the object to be plated is reliably prevented, and since the gas does not adhere to the work, the jet flow rate can be reduced, thereby making the thickness of the plating film uniform and the like.

In addition, the jet chamber is provided with an ejection pipe for ejecting the plating solution, and the plating solution is ejected from the ejection pipe to the jet chamber, and the plating solution discharge port is provided in communication with the jet chamber. The flow of the plating solution jet is good, so that the object to be plated can be satisfactorily spray-plated, and the anode chamber is provided with an introduction pipe for introducing the plating solution into the anode vertebrae and communicates with the anode chamber to perform plating. A liquid outlet is provided to allow the plating solution to flow separately from the flow of the plating solution in the jet chamber, so that the plating solution stays in the anode chamber and gas generated from the anode adheres to the diaphragm, and the plating target Since the conduction between the object and the anode is hardly hindered, and the gas escapes smoothly from the anode chamber, good plating is also guaranteed from this point. A plating solution collecting pipe is connected to the bottomed cylindrical cover, and is returned to the plating solution storage tank, so that it is circulated.

Hereinafter, an embodiment of the present invention will be described with reference to FIG.

〔Example〕

1 shows a jet plating apparatus according to one embodiment of the present invention. The plating apparatus 1 includes a bottomed cylindrical cover 2 and a bottomed cylindrical cell 3 disposed therein. I do. In this cylindrical cell 3, a circular diaphragm supporting plate 4 is disposed at a substantially central portion in the axial direction so as to vertically divide the inside of the cell 3 along the radial direction. A diaphragm 5 having a large number of fine holes is attached to the lower surface, and an upper jet chamber 6 and a lower anode chamber 7 are formed in the cell 3. The two chambers 6 and 7 communicate with each other through a plurality of communication holes 8 formed in the support plate 4 along the circumferential direction thereof and fine holes in the diaphragm 5.

A ring-shaped step 9 is formed at the upper end of the jet chamber 6 (the inner peripheral edge of the upper end of the cell 3).
10 is placed, and the tip of the plating solution jetting pipe 11 is positioned at the center of the lower end face of the cell 3 and the diaphragm 5 and the diaphragm support plate 4.
The plating solution in the plating solution storage tank 12 is blown up by the operation of the pump 13 into the jet flow chamber 6 by the operation of the pump 13, and the plating object 10 It can be sprayed on the lower surface.
In addition, a plating solution discharge port 14 is formed in the upper part of the side wall of the cell 3 below the stepped part 9 and in close proximity to the stepped part 9 to communicate the upper part of the jet chamber 6 with the inside of the cover 2.

The anode chamber 7 is provided with an anode 15 at a lower portion thereof and a through hole 16 formed in a peripheral portion of a lower end surface of the cell 3.
One end of a plating solution introduction pipe 17 is connected to the anode chamber 7 by the operation of a pump 18.
A plating solution is introduced therein. Further, a plating solution outlet 19 is formed on the side wall of the cell 3 at a position close to the lower side of the diaphragm 5 and substantially opposite to the plating solution introduction pipe. One end of the outflow pipe 20 is connected, and the plating solution in the anode chamber 7 passes through the outflow pipe 20 and flows out of the other end into the cover 2.

A plating solution collecting pipe 21 is connected to the cover 2 so that the plating solution discharged from the jet chamber 6 and the anode chamber 7 is returned to the plating solution storage tank 12 through the collecting pipe 21. ing.

Here, the diaphragm 5 can be made of a material such as polypropylene, and a commercially available product such as Kanecaron 5000 (trade name, manufactured by Kaneka Chemical Industry Co., Ltd.) can be used. The thickness is preferably 0.1 to 0.5 mm. Also the anode
15 may be a soluble anode or an insoluble anode.

Next, when electroplating the object to be plated 10 by using the above-mentioned jet plating apparatus, after the object to be plated 10 is arranged at the upper end of the jet chamber 6, the pumps 13 and 18 are respectively operated to supply the plating solution. The plating solution is blown upward from the ejection pipe 11 into the jet chamber 6 and sprayed on the lower surface of the plating object 10, and the plating solution is introduced into the anode chamber 7 from the plating solution introduction pipe 17. In this case, the flow rate of the plating solution flowing through the jet chamber 6 is generally 0.3 to 0.6.
m / min, the flow rate of the plating solution flowing through the anode chamber 7 is 0.1 to 0.3 m / m
It is preferable to be in. The plating solution sprayed on the lower surface of the plating object 10 flows laterally along the lower surface of the plating object 10 and is discharged from the plating solution discharge port 14 to the cover 2. On the other hand, the plating solution introduced into the anode chamber 7 from the plating solution introduction pipe 17 flows upward, then flows along the lower surface of the diaphragm 5, and flows out of the outflow pipe 20 into the cover. The plating solution discharged and discharged from the jet chamber 6 and the anode chamber 7 is then returned to the plating solution storage tank 12 through the collection pipe 21,
It is sent again to the ejection pipe 11 and the plating solution introduction pipe 17,
Used for circulation.

According to the jet plating apparatus 1, the gas and slime generated at the anode 15 are prevented from moving from the anode chamber 7 to the jet chamber 6 by the diaphragm 5 located above the anode 15, and these adhere to the object 10 to be plated. This can effectively prevent the occurrence of defects caused by the gas or slime adhering to the object to be plated. Further, the gas or slime that is blocked by the diaphragm 5 and reaches the lower surface of the diaphragm 5 flows along the lower surface of the diaphragm 5 with the plating solution, and quickly flows out of the anode chamber 7 without staying on the lower surface of the diaphragm 5. Therefore, the gas is prevented from adhering to the diaphragm 5 and hindering the conduction between the object 10 to be plated and the anode 15. Also in this case,
Since the gas is prevented from adhering to the object to be plated, the amount of the plating solution sprayed onto the object to be plated 10 can be reduced, whereby the bump shape can be made uniform when the bumps are formed.

Actually, an attempt was made to form a bump electrode of about 50 μm on a diode semiconductor wafer by using a jet plating apparatus 1 as shown in FIG. First, the diode semiconductor wafer was nickel-plated as a base plating, and then a silver bump was formed thereon. In this case, the anode 15 was used for the nickel plating, and the anode 15 was used for the silver plating.
15 was insoluble platinum, but in each case, there was no gas adhesion, and in the former, there was no slime adhesion, and a good-shaped silver bump electrode was formed on the diode semiconductor wafer without plating failure. Was completed.

In the apparatus of the present invention, the arrangement of the object to be plated, the plating solution ejection pipe, the plating solution discharge port, the plating solution introduction pipe, the plating solution discharge pipe, and the like is not limited to the above-described embodiment, and the present invention is not limited thereto. Various changes may be made without departing from the gist.

〔The invention's effect〕

As explained above, the jet plating apparatus of the present invention is:
With the above-described configuration, it is possible to effectively prevent plating defects due to the attachment of gas and slime.

[Brief description of the drawings]

FIG. 1 is a partially omitted sectional view showing an example of a jet plating apparatus of the present invention, and FIG. 2 is a partially omitted sectional view showing a conventional jet plating apparatus. 1 ... jet type plating apparatus, 3 ... cell, 5 ... diaphragm, 6
… Jet chamber, 7… Anode chamber, 10… Plating object, 11…
Ejection pipe, 14… Plating solution outlet, 15… Anode, 17…
… Plating solution introduction pipe, 20 …… Plating solution outflow pipe, 21
...... Collecting pipe.

 ──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-62-297495 (JP, A) JP-A-63-216998 (JP, A)

Claims (1)

(57) [Claims] An object to be plated is disposed at an upper end of a cylindrical cell disposed in a bottomed cylindrical cover, and an anode is disposed at a lower part of the cylindrical cell. In a jet-type plating apparatus in which an electroplating solution is blown up and an electroplating solution is sprayed on the lower surface of the object to be plated while electroplating the lower surface, a large number of fine particles are formed in the cylindrical cell so as to partition the cell up and down. A diaphragm having holes is provided, and an upper jet chamber and a lower anode chamber communicating with each other through the fine holes of the diaphragm are formed in the cylindrical cell, and an object to be plated is formed at an upper end of the jet chamber. In addition, a jet pipe for jetting a plating solution is provided in the jet chamber, and a plating solution discharge port for communicating the jet chamber with the inside of the cover is formed in the cylindrical cell, and an anode is arranged in the anode chamber. And the same plating solution as the above plating solution was introduced into the anode chamber. Introducing pipes provided, and to form a plating liquid outlet port for communicating the anode chamber and in said cover,
A jet plating apparatus, wherein a plating solution collecting pipe is connected to the cover.