JP4765207B2 - Full-surface electroplating apparatus and method for manufacturing full-plated lead frame thereby - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a reel-to-reel full-surface electroplating apparatus of a hoop-like sheet metal product continuous feeding system and a method of manufacturing a full-plated lead frame thereby .
[0002]
[Prior art]
Conventionally, an apparatus for electroplating a hoop-like sheet metal product such as a lead frame with a continuous feed type reel reel is disclosed in Japanese Patent Laid-Open No. 5-70988.
[0003]
FIG. 5 is a cross-sectional view showing the entire conventional electroplating apparatus. The electroplating apparatus includes a liquid receiving tank 1 having a plating solution outlet and an anode disposed in the liquid receiving tank 1. 6, a shielding plate 8, an outer tank 2 that receives the plating liquid overflowed from the liquid receiving tank 1, a main tank 4 that stores the plating liquid, and a liquid circulation path 3 that returns the plating liquid from the outer tank 2 to the main tank 4. And a pump 5 that sucks the plating solution from the main tank 4 and pumps it to the liquid receiving tank 1. 7 in the figure is a product placed in the liquid receiving tank 1.
[0004]
The entire surface electroplating apparatus performs a plating process on the entire surface of the product 7 by passing a constant current between the anode 6 and the product 7.
[0005]
[Problems to be solved by the invention]
By the way, in the conventional full-surface electroplating apparatus, even if the shielding plate 8 in the liquid receiving tank 1 is set in the vicinity of the product 7, the shielding plate 8 is flat, and the product 7 is transported above and below the product 7. Since a space is required to have a margin for fluctuations, the current density on the surface of the product 7 is higher at both ends than the center, and the plating film thickness at both ends is thicker than the center. Further, since the space fluctuates due to fluctuations in the transport position, there is a problem that the current density on the surface of the product 7 fluctuates and the distribution of the plating film thickness fluctuates. Also, if the plating film thickness at both ends becomes extremely thick, it may cause plating abnormalities such as burning and burrs, and the plating adheres to unnecessary portions, so that the plating material that is an expensive noble metal such as Pd, Au, Ag, etc. It becomes useless.
[0006]
An object of the present invention is to provide a full-surface electroplating apparatus capable of controlling the distribution of the plating film thickness ideally and constantly while paying attention to the conventional problems.
[0007]
[Means for Solving the Problems]
In order to solve this problem, the present invention provides a liquid receiving tank having a plating liquid ejection port and an electrode through which a current flows, a main tank for storing the plating liquid, and the plating liquid flowing out from the liquid receiving tank to the main tank. A liquid circulation path, a pump that sucks the plating solution from the main tank and pumps it to the receiving tank, and an upper shielding mask and a lower shielding mask that surround both ends of the product to be plated in the receiving tank with an insulator. The upper shielding mask and the lower shielding mask are disposed in the immediate vicinity surrounding the end face and side surface of the product, are fixed to the lower shielding mask and support the upper shielding mask so as to be movable up and down, and the upper shielding mask and the lower shielding mask. The upper shielding mask is mounted with a float and is supported by a spacer that can be attached to and detached from the lower shielding mask or stay, and a push screw that presses and fixes the upper shielding mask to the spacer. And by, suspended in the plating solution to follow the transport position variation of products, the entire surface electroplating reel tow reel hoop sheet metal products continuous feed system, characterized in that it has not exert contact load product A device.
[0008]
According to the present invention, the current density on the end face of a product to be plated, such as a lead frame, can be reduced, the plating film thickness distribution can be ideally controlled, and the product is not damaged or damaged. A product having an ideal plating film thickness distribution can be obtained.
[0009]
DETAILED DESCRIPTION OF THE INVENTION
According to the first aspect of the present invention, there is provided a liquid receiving tank having a plating liquid ejection port and an electrode for passing an electric current, a main tank for storing the plating liquid, and plating from the liquid receiving tank to the main tank. A liquid circulation path through which the liquid flows out, a pump that sucks the plating liquid from the main tank and pumps it to the liquid receiving tank, an upper shielding mask that surrounds both ends of the product to be plated in the liquid receiving tank with an insulator, and A lower shielding mask, and the upper shielding mask and the lower shielding mask are disposed in the vicinity of the pole surrounding the end face and the side surface of the product, and are fixed to the lower shielding mask and support the upper shielding mask so as to be vertically movable. A stay, a spacer provided between the upper shielding mask and the lower shielding mask, the spacer being detachable from the lower shielding mask or the stay, and a pressing member that presses and fixes the upper shielding mask to the spacer. It is supported by a screw, by the float on said shielding mask is mounted, floating in the plating solution following the transport position variations of the product, which was configured not added contact load product There is an effect that a product having an ideal and constant distribution of plating film thickness can be obtained without damaging the product such as scratches and deformation.
[0010]
According to a second aspect of the present invention, there is provided a method of manufacturing a full-plated lead frame by the full-surface electroplating apparatus according to the first aspect, and the full-plated lead frame manufactured thereby has a central lead and rails at both ends. Since the plating film thickness of the rails is equal or thinner at both ends, the distribution of plating film thickness of the leads used by customers is uniform, high quality, and the plating film thickness of the rails discarded without being used by the customers is thin. This has the effect of obtaining a low-cost product with a reduced amount of use.
[0011]
Hereinafter, embodiments of the present invention will be described with reference to FIGS.
[0012]
(Embodiment 1)
FIG. 1 is an overall cross-sectional view of a full product electroplating apparatus of a product longitudinal feed system according to Embodiment 1 of the present invention, and FIG. 2 is a cross-sectional view showing the inside of a liquid receiving tank in the full surface electroplating apparatus.
[0013]
In FIG. 1, the configuration other than the inside of the liquid receiving tank 1 described in FIG.
[0014]
This full surface electroplating apparatus applies a plating process to the entire surface of the product 7 by passing a constant current between the anode 6 and the product 7 in the liquid receiving tank 1, but as shown in FIG. A shielding mask 9 that surrounds both ends of the product 7 such as a lead frame to be plated on the whole surface with an insulator is provided to restrict the concentration of metal ions in the plating solution to both ends of the product 7.
[0015]
The shielding mask 9 is adjusted in buoyancy, floats in the plating solution in a state where the distance from the product 7 is kept constant, and does not apply a large contact load that causes damage such as scratches and deformation to the product 7. It follows the fluctuation of the transport position of the product 7. In addition, by optimally setting the width and height of the groove surrounding both ends of the product 7 inside the shielding mask 9, a product having an ideal and constant distribution of the plating film thickness can be obtained.
[0016]
The shielding mask 9 and its related parts are a front view showing details of the shielding mask part inside the liquid receiving tank of FIG. 3A and a sectional view of a product guide part in the shielding mask of FIG. 3B. And it is comprised as shown in sectional drawing of the mask holding | maintenance part of FIG.3 (c).
[0017]
That is, the shielding masks 9a and 9b are paired up and down, are made of an insulating material made of a synthetic resin such as hard vinyl chloride, and are thinned for weight reduction. The float 9c is made of an insulator made of a synthetic resin having a low specific gravity such as foamed polystyrene, and is coupled to the shielding mask 9a to generate buoyancy for floating the entire shielding mask in the plating solution. The upper and lower guides 9d are made of high-hardness wear-resistant insulators such as ceramics, and are provided inside the shielding masks 9a and 9b to receive both edges of the product 7 and maintain a vertical distance from the shielding masks 9a and 9b. It is supposed to be. The left and right guides 9e are made of an insulating material made of a synthetic resin such as polypropylene, and receive both side surfaces of the product 7 so as to maintain a horizontal distance from the shielding masks 9a and 9b. The stay 9f is made of an insulating material made of a synthetic resin such as hard vinyl chloride, and is fixed to the lower shielding mask 9b in order to connect the upper and lower shielding masks 9a and 9b according to the width of the product 7, and the upper shielding mask 9a. Moves up and down along the stay 9f. The spacer 9g is made of an insulating material made of a synthetic resin such as hard vinyl chloride, and can be attached to or detached from the lower shielding mask 9b or the stay 9f in order to maintain the distance between the shielding masks 9a and 9b in accordance with the width of the product 7. Installed. The push screw 9h is made of an insulator made of a synthetic resin such as hard vinyl chloride, and presses and fixes the upper shielding mask 9a against the spacer 9g. By using a spacer 9g and a set screw 9h having a length corresponding to the width of the product 7, it is possible to cope with model switching.
[0018]
In this embodiment, there are two product guide portions before and after the shielding mask. However, when the shielding mask is long, it is added as necessary. Needless to say, the material of the above-described member is not immersed in the plating solution. Moreover, although the embodiment in the product vertical feed system has been described, the product horizontal feed system can be similarly implemented.
[0019]
(Embodiment 2)
FIG. 4 shows a plan view of an example lead frame manufactured by the full-surface electroplating apparatus of the present invention.
[0020]
In FIG. 4, 7a is an inner lead connected to the semiconductor chip, and 7b is an outer lead connected to the substrate, which is a part used by customers. 7c is a rail for connecting individual lead frames to form a hoop, which is discarded by the customer after final assembly.
[0021]
Here, as a feature, the plating film thickness of the inner lead 7a and the outer lead 7b is equally uniform, and the plating film thickness of the rail 7c is equal to or thinner than that of the lead.
[0022]
In the second embodiment, the example of the lead frame has been described. However, the present invention can be similarly applied to other hoop-like metal thin plate products.
[0023]
【The invention's effect】
As is clear from the above description, according to the present invention, in the overall plating product of the hoop-like metal thin plate, a product having an ideal thickness distribution without causing damage such as scratches or deformation to the product is obtained. In addition, an advantageous effect that the amount of plating material used can be reduced can be obtained by making the distribution of the plating film thickness in a necessary portion uniform and reducing the plating film thickness in an unnecessary portion.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view showing the whole of a full length electroplating apparatus of a product longitudinal feed system according to Embodiment 1 of the present invention. FIG. 2 is a cross sectional view showing the inside of a liquid receiving tank in the full surface electroplating apparatus. a) Front view showing details of the shielding mask part inside the liquid receiving tank (b) Cross-sectional view of the product guide part in the shielding mask (c) Cross-sectional view of the mask holding part [FIG. 4] Full-surface electroplating apparatus of the present invention FIG. 5 is a cross-sectional view showing the whole of a conventional full surface electroplating apparatus.
1 Liquid receiving tank 2 Outer tank 3 Liquid circulation path 4 Main tank 5 Pump 6 Anode 7 Product (lead frame)
7a Inner lead 7b Outer lead 7c Rail 8 Shield plate 9 Shield mask 9a Upper shield mask 9b Lower shield mask 9c Float 9d Vertical guide 9e Left and right guide 9f Stay 9g Spacer 9h Push screw

Claims (2)

A liquid receiving tank having a plating liquid outlet and an electrode through which a current flows, a main tank for storing the plating liquid, a liquid circulation path for flowing the plating liquid from the liquid receiving tank to the main tank, and the main tank A pump that sucks a plating solution from the liquid receiving tank and pumps it to the liquid receiving tank; and an upper shielding mask and a lower shielding mask that surround both ends of a product to be plated in the liquid receiving tank with an insulator. And a lower shielding mask disposed near the end face and side surface of the product, and a stay fixed to the lower shielding mask and supporting the upper shielding mask so as to be movable up and down, the upper shielding mask and the lower shielding mask Supported by a spacer that is detachably attached to the lower shielding mask or the stay, and a push screw that presses and fixes the upper shielding mask to the spacer. A hoop-like metal sheet product continuous feed that floats in the plating solution to follow the change in the transport position of the product and prevents a contact load from being applied to the product. Full-surface electroplating equipment for the reel reel type. A method for producing a full-surface plated lead frame by the full- surface electroplating apparatus according to claim 1.

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