JPH0342041Y2 - - Google Patents

Description

[Detailed description of the invention] [Industrial application field] The present invention is applicable to surface treatments such as plating,
The present invention relates to a hanger for surface treatment that has less variation in plating film thickness, can increase the number of objects to be treated even with the same size hanger as conventional ones, and can be used for high-speed plating processing. .

[Conventional technology]

For example, when plating the entire surface of a lead frame for semiconductor manufacturing, conventionally, the lead frame is connected integrally with a suspension arm 4 as shown in FIG. 3 using positioning holes for assembly of the lead frame. A substantially rectangular support frame 1 is constituted by a substantially parallel vertical arm 10 and a beam 11 connected to the vertical arm 10, and a support branch 9 is planted at a corresponding position on at least one side of the vertical arm 10, Positioned at equal distances from the vertical arms 10 of support branches 9 of equal length planted at equal intervals on the support frame 1 of the surface treatment hanger, which is formed to hang the workpiece on the support plate 9. The entire surface of the hanger is plated by immersing the hanger in a plating solution.

[Problem that the invention attempts to solve]

However, when using such a conventional hanger, it has been said that high-speed plating processing is impossible because increasing the stirring speed of the plating solution causes the lead frame to easily come off the support branch 9. . For this reason, when processing large quantities of products,
A large treatment tank had to be used, which inevitably required a large floor space. In addition, since the lengths of the supporting branches 9 are all the same, in order to prevent the upper and lower lead frames from contacting each other and to facilitate the flow of current to the opposing electrodes, the supporting branches 9 adjacent to each other are
There is a problem that the spacing between lead frames needs to be 1.2 to 1.3 times the width of the lead frame, and the number of lead frames that can be processed with a hanger of a certain size is small.
Furthermore, there was a problem in that the plating film thickness of the plated product varied by as much as ±0.6 μm for a plating film thickness of 5 μm, depending on the hanging position.

The present invention solves these problems, has less variation in plating film thickness, can increase the number of objects to be processed on hangers of the same size as conventional ones, and can also be used for high-speed plating processing. The purpose is to obtain a hanger for surface treatment.

[Means for solving problems]

In order to solve the above problems and achieve the above purpose, the present inventor made repeated efforts to achieve the purpose by planting support branches of different lengths alternately and at equal intervals on the vertical arm of the hanger. After recognizing that the invention could be obtained, the present invention was completed. That is, in the present invention, a substantially rectangular support frame is constituted by vertical arms that are substantially parallel to each other and are integrally connected to the suspension arms, and beams that connect the vertical arms, In a surface treatment hanger in which a support branch is planted at a position, a workpiece to be treated is hung on the support branch, and the support frame is immersed in a surface treatment solution, the corresponding support branch in each vertical arm is connected to a short support branch. This hanger for surface treatment consists of alternating branches and long support branches.

〔Example〕

Next, embodiments of the present invention will be described based on the attached drawings.

FIG. 1 is a perspective view showing an embodiment of the surface treatment hanger of the present invention, and FIG. 2 is a perspective view showing an example of a state in which a lead frame is suspended from the surface treatment hanger of the present invention.

Embodiment 1 is a support frame that uses copper rods with a diameter of 10 mm to include vertical arms 10 that are substantially parallel to each other and are integrally connected to a curved suspension arm 4, and a beam that connects the vertical arms 10. 11 to form a substantially rectangular shape, and the distance from the suspension top 6 of the suspension arm 4 to the tip 7 of the vertical arm 10 is 400 mm. 2 is a short supporting branch,
A stainless steel rod with a diameter of 0.8 mmφ is attached to both vertical arms 10,
10, at a corresponding position such that the distance from the vertical arm 10 to the tip suspension part 5 at the tip of the short support branch 2 is 30 mm, and in the illustrated example , are implanted through the vertical arm 10 so as to be provided on both sides of the vertical arm 10.
3 is a long support branch, and a stainless steel rod with a diameter of 0.8 mmφ similar to the short support branch 2 is attached to both vertical arms 10 and 1.
0, at a corresponding position such that the distance from the vertical arm 10 to the tip suspension part 5 at the tip of the long support branch 3 is 35 mm, and in the illustrated example , are implanted so as to be provided on both sides of the vertical arm 10, passing through the vertical arm 10 alternately with the short supporting branches 2 with a distance of 30 mm between them.

In this way, the hanger for surface treatment of the present invention, which has five short support branches 2 and five long support branches 3 each attached to the vertical arm 10, has a thickness of 3 mm, a width of 24.6 mm, and a length of 3 mm.
A total of 20 lead frames 8 made of 150 mm 42 alloy are connected to each positioning hole at the end suspension part 5 of each support branch.
0.7A/ using cyan silver plating solution.
Silver plating was applied to a thickness of 5 μm under the conditions of dm ² and 630 seconds. As a result, the variation in the overall plating film thickness with respect to the plating film thickness of 5 μm was ±0.35 μm.

Comparative Example Using the same plating bath and plating liquid as in the example, support branches 9 of the same size and length as in the example were attached to both vertical arms 1.
A lead frame of the same size as in the example was hung using a conventional surface treatment hanger with 8 wires inserted through 0 and 10, and silver plating was performed under the same conditions as in the example. did.

This result shows that the maximum number of lead frames processed per surface treatment hanger is 16.
The variation in the plating film thickness was also large at ±0.6 μm for a plating film thickness of 5 μm.

[Effect of idea]

The present invention is a surface treatment hanger in which short support branches and long support branches are alternately arranged on both vertical arms of the support frame, so it can be processed even if it is the same size as a conventional surface treatment hanger. Great effects have been recognized, including the ability to increase the amount of material to be processed and to reduce variation in plating film thickness in various parts of plated products by 20 to 50% compared to conventional methods.

[Brief explanation of drawings]

FIG. 1 is a perspective view showing one embodiment of the hanger for surface treatment of the present invention, FIG. 2 is a perspective view showing a state in which a lead frame is suspended from the hanger for surface treatment of the present invention, and FIG. 3 is a perspective view of a conventional hanger for surface treatment of the present invention. FIG. 2 is a perspective view showing an example of a hanger for surface treatment. 1...Support frame, 2...Short support branch, 3...Long support branch, 4...Suspension arm, 5...Tip suspension part, 6...Suspension top, 7...Tip part, 8...Lead frame ,
9...Support branch, 10...Vertical arm, 11...Beam.

Claims (1)

[Scope of utility model registration request] A substantially rectangular support frame is constituted by vertical arms that are substantially parallel to each other and are integrally connected to the suspension arms, and beams that connect the vertical arms, and support branches are planted at corresponding positions on at least one side of the vertical arms. In the surface treatment hanger, in which the article to be treated is hung on the support branches and the support frame is immersed in the surface treatment solution, the corresponding support branches in each of the vertical arms are divided into short support branches and long support branches. Surface treatment hangers arranged alternately.