JPH01198496A - Spot plating apparatus - Google Patents

Abstract

PURPOSE:To make the current distribution of a plating region uniform and to form plating of a uniform thickness by interposing a netlike plating electrode between the part of a body to be spot-plated and an anode nozzle. CONSTITUTION:A body 1 to be plated is fixed with an upper mask 13 and a lower mask 14 except the part 12 to be spot-plated and a plating soln. 16 fed by a pump 18 is sprayed on the part 12 from an anode nozzle 15. At this time, a netlike plating electrode 1 is interposed between the part 12 and the nozzle 15 and DC bias is impressed on the part 12, the nozzle 15 and the electrode 1 from a DC power source 19. The current distribution of the region sprayed with the plating soln. 16 is made uniform and the thickness of plating is prevented from varying.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Applications] The present invention relates to a spot plating device that can make the plating thickness uniform. [Prior Art] FIG. 2 is a sectional view showing an example of a conventional spot plating apparatus.

In this figure, 11 is a semiconductor lead frame as an example of an object to be plated, and 12 is the semiconductor lead frame 1.
1, a spot plating section; 13, an upper mask of the semiconductor lead frame 11; 14, a lower mask of the semiconductor lead frame 11; 15, an electrode anode nozzle for spraying a plating solution 16 onto the spot plating section 12; 17;
18 is a pump that supplies the plating solution 16; 19 is a pump that applies a negative level to the semiconductor lead frame 11; This is a DC power supply that applies a positive level to the nozzle 15.

Next, the operation will be explained.

In the conventional spot plating apparatus shown in FIG.
All but 2 are masked and fixed by an upper mask 13 and a lower mask 14'. Next, the nozzle plate 17
A plating solution 16 supplied by a pump 18 is sprayed onto the spot plating section 12 from an anode nozzle 15 attached to the electrode. At this time, the DC bias is applied to the spot plating part 12 and the electrode anode by the DC power supply 19.
The voltage is applied to the do nozzle 15. This DC bias makes it easy for the plating solution 16 to adhere to the spot plating portion 12.

[Problem to be solved by the invention]

Since the conventional spot plating apparatus is configured as described above, the spot plating section 12 and the electrode anode nozzle 1
There was a problem in that the current distribution between the spot plating section 12 and the electrode anode nozzle 15 was not uniform due to the difference in the opposing area between the spot plating section 12 and the electrode anode nozzle 15.

For this reason, there is a large variation in the thickness of the plating layer in the spot plating area 12, and when trying to obtain the minimum necessary plating thickness, a very thick plating layer is formed in other parts, which increases the material cost. It was disadvantageous in terms of quality reliability, etc.

This invention was made to solve the above-mentioned problems, and provides a spot plating device that can equalize the current distribution between the spot plating section □ and the electrode anode nozzle and make the thickness of the plating layer uniform. The purpose is to obtain.

(Means for Solving the Problems) A spot plating apparatus according to the present invention includes a mesh plating electrode provided between a spot plating part and an electrode anode nozzle to equalize current distribution between the spot plating part and the spot plating part. This is what I did.

[Effect]

In this invention, the mesh-like plating electrode provided between the spot plating part and the electrode anode nozzle equalizes the current distribution between the spot plating part and the electrode anode nozzle.

(Embodiment) FIG. 1 is a sectional view of a spot plating apparatus showing an embodiment of the present invention.

In this figure, the same reference numerals as in FIG. 2 indicate the same or corresponding parts, and 1 is a wire-shaped plating electrode according to the present invention, which is provided between the spot plating part 12 and the electrode anode nozzle 15, and is provided between the spot plating part 12 and the electrode anode nozzle 15. 12 to make the current distribution uniform. Note that the mesh-shaped plated electrode 1 is coated with a plating solution 1.
Any structure may be used as long as it does not hinder the passage of 6.

Next, the operation will be explained.

In the spot plating apparatus of the present invention shown in FIG. 1, first, a semiconductor frame 11 except for its spot plating portion 12 is masked and fixed with an upper mask 13 and a lower mask 14. Next, the plating solution 16 supplied by the pump 18 from the electrode anode nozzle 15 attached to the nozzle plate 17 passes through the cotton-like plating electrode 1 and is sprayed onto the spot plating section 12 . It fills the space between the nozzle plate 17 and the spot plating section 12. At this time, a DC bias is applied by the DC power supply 19 to the spot plating section 12 and the electrode anode nozzle 15. The voltage is applied to the wire-shaped plating electrode 1.

In this case, a net-shaped plating electrode is provided facing the entire surface of the spot plating part 12, and a DC positive bias is applied in two stages together with the electrode anode nozzle 15, so that the spraying of the plating solution 16 is carried out by the current in the area. The distribution is made uniform and variations in plating thickness can be eliminated.

Here, the data of the spot plating portion 12 of the semiconductor lead frame 11 produced by the spot plating apparatus of the present invention is shown below.

The conditions are that the size of the spot cleaning part 12 is 13X 13
mm, and the minimum required thickness of the plating layer is 4 μm.

The plating thickness in the conventional example was 4.0 to 12.0 μm and the average plating thickness was 8.011 m, whereas the plating thickness in the device of the present invention was 4.0 to 5.5 μm and the average plating thickness was 4.75 μm. Ta. Therefore, the variation in plating thickness is 1.5/8
．． 0, approximately 115 or less. In addition, the average plating thickness is 8
．． By going from 0 μm to 4.75 μm, the material cost is saved by about 40%. Furthermore, it goes without saying that quality reliability is improved by reducing variations in plating thickness. Furthermore, it goes without saying that the object to be plated is not limited to the semiconductor lead frame 11.

(Effects of the Invention) As described above, the present invention includes a wire-shaped plating electrode that is provided between the spot plating part and the electrode anode nozzle to equalize the current distribution between the spot plating part and the plating area. This has the effect of making it possible to make the current distribution uniform, and to obtain a plating thickness that is uniform in size.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a spot plating apparatus according to an embodiment of the present invention, and FIG. 2 is a sectional view of an example of a conventional spot plating apparatus. In the figure, 1 is a mesh-like plating electrode, 12 is a spot plating section, 15 is an electrode anode nozzle, and 16 is a plating solution. Note that the same reference numerals in each figure indicate the same or corresponding parts. Agent Masuo Oiwa (2 others) Figure 1 Figure 2

Claims (1)

[Claims] A spot plating device having an electrode anode nozzle that sprays a plating solution onto a spot plating section, the mesh plating provided between the spot plating section and the electrode anode nozzle to equalize current distribution between the spot plating section and the spot plating section. A spot plating device characterized by being equipped with an electrode.