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KR-102963039-B1 - Membrane-based electroplating mold apparatus

KR102963039B1KR 102963039 B1KR102963039 B1KR 102963039B1KR-102963039-B1

Abstract

The present invention relates to a membrane-based electroplating mold device capable of improving the cleanliness of a plating solution and the uniformity and quality of a plating layer by optimizing current distribution and ion transfer and blocking the movement of impurities, by not only adjusting the distance between an anode and a cathode but also placing a membrane that transmits only selected metal ions between them. More specifically, the invention comprises: a mold body having an inner chamber with an open bottom and an ion-permeable membrane installed to traverse the inner chamber in a transverse direction, wherein the inner chamber is divided into an upper chamber for receiving a plating solution and a lower chamber in which a space is formed; an anode disposed in the upper chamber of the mold body and connected to the positive (+) electrode of an external power supply; and a cathode block having a seating surface on its upper side for placing a workpiece, which is introduced into the lower chamber of the mold body, causes the placed workpiece to adhere to the ion-permeable membrane, and is connected to the negative (-) electrode of an external power supply. The invention is characterized by including a variable connection bar that penetrates the center of the mold body in a vertical direction and is connected to the anode, and is equipped with a moving means for moving the anode in a vertical direction so that the distance between the anode and the cathode block is varied.

Inventors

  • 황규정
  • 박수진

Assignees

  • (주)케이로보틱스

Dates

Publication Date
20260511
Application Date
20251216

Claims (7)

  1. A mold body having an inner chamber with an open bottom and an ion-permeable membrane installed to traverse the inner chamber in a transverse direction, wherein the inner chamber is divided into an upper chamber for accommodating a plating solution and a lower chamber in which a space is formed; A positive electrode disposed in the upper chamber of the above-mentioned mold body and connected to the positive (+) pole of an external power supply; A cathode block having a seating surface on the upper part for a workpiece to be plated, which is introduced into the lower chamber of the mold body and connected to the negative (-) electrode of an external power supply, so that the workpiece to be plated placed thereon adheres to the ion-permeable membrane; and A membrane-based electroplating mold device characterized by including: a variable connection bar that penetrates the center of the mold body in a vertical direction and is connected to the anode, and is equipped with a moving means for moving the anode in a vertical direction so that the distance between the anode and the cathode block is varied.
  2. In Article 1, The above ion-permeable membrane is, A membrane-based electroplating mold device characterized by being an ion exchange membrane that allows only selective metal ions to pass through from the plating solution of the upper chamber.
  3. In Article 1, The above mold body is, A membrane-based electroplating mold device characterized by the fact that an upper mold forming the upper chamber and a lower mold forming the lower chamber are mutually separably connected with respect to the ion-permeable membrane, and a first packing member interposed between the upper mold and the lower mold is provided.
  4. In Paragraph 3, The above upper mold is, A membrane-based electroplating mold device characterized by having an inlet hole and an outlet hole respectively communicating with the upper chamber at mutually spaced positions.
  5. In Paragraph 4, A membrane-based electroplating mold device characterized by further comprising: a flow control means that performs any one of circulation, stirring, or flow rate control of a plating solution contained in an upper chamber, including a connecting line connecting the inlet hole and the outlet hole, and a flow pump mounted on the connecting line.
  6. In Paragraph 3, The above cathode block is, A second packing member is provided, which is mounted to surround the outer surface and adheres to the inner surface of the lower chamber. The above lower mold is, A membrane-based electroplating mold device characterized by having one or more flow holes formed through a position higher than the position where the second packing member is placed while the cathode block is inserted.
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Description

Membrane-based electroplating mold apparatus The present invention relates to a membrane-based electroplating mold device capable of improving the cleanliness of the plating solution and the uniformity and quality of the plating layer by optimizing current distribution and ion transfer and blocking the movement of impurities by not only adjusting the distance between the anode and the cathode but also placing a membrane that allows only selected metal ions to pass through between them. Generally, in the silver (Ag) electroplating process of semiconductor lead frames, a method has been widely applied in which an anode and a cathode are fixedly placed in an open plating tank and silver ions leached from a soluble silver anode are utilized. However, this traditional method has a fundamental limitation in that sludge, metal fragments, and oxidation byproducts generated at the anode diffuse into the entire plating solution, contaminating the plating solution on the cathode side. In addition, organic additives in the plating solution gradually decompose during the electrolysis process, and as these decomposition byproducts continue to accumulate in the solution, they destabilize the composition of the plating solution and rapidly shorten its lifespan. As a result, the stability of plating quality is compromised, and the need to repeatedly filter and replace the plating solution leads to increased process costs and management burdens. In addition, in conventional processes using soluble anodes, the dissolution rate of silver metal is not constant, so the concentration of silver ions in the plating solution fluctuates over time, which acts as a factor in quality variation, such as the grain size of the plating film becoming rough or the variation in plating thickness increasing. In particular, in open plating tank structures, the distance between the anode and cathode is fixed, making it difficult to respond flexibly to changes in lead frame shape or current conditions. Furthermore, due to shape dependency where the current is concentrated in a specific area, there were problems such as defects like edge burns or localized roughness occurring repeatedly. FIG. 1 is a side view showing an apparatus according to one embodiment of the present invention. FIG. 2 is an exploded assembly diagram of a device according to one embodiment of the present invention. FIGS. 3A and FIGS. 3B are side views showing the configuration of a mold body according to one embodiment of the present invention. FIGS. 4a and FIGS. 4b are side views showing the configuration of a cathode block according to one embodiment of the present invention. FIG. 5 is an operating state diagram of a device according to one embodiment of the present invention. FIG. 6 is a partial enlarged view showing a flow hole of a lower mold according to one embodiment of the present invention. FIG. 7 is a side view showing the configuration of a variable adjustment bar according to one embodiment of the present invention. In describing the present invention, terms and words used in this specification and claims must be interpreted in a meaning and concept consistent with the technical spirit of the invention, based on the principle that the inventor can appropriately define the concept of the terms to best describe his invention. Preferred embodiments of the present invention will be described below with reference to the drawings. Referring to FIGS. 1 and 2, the apparatus (1) of the present invention may be configured to include a mold body (10) in which a plating solution (3) is isolated and contained by an ion-permeable membrane (120) and the bottom is open, an anode (20) disposed within the plating solution (3) of the mold body (10), and a cathode block (30) that is introduced into the interior of the mold body (10) and faces the ion-permeable membrane (120). The above mold body (10) has an inner chamber with an open bottom, and the cathode convex (30) can be introduced through the open bottom portion. And the mold body (10) is provided with an ion-permeable membrane (120) installed to cross the inner chamber in a transverse direction, so that the inner chamber can be separated into two spaces. That is, the inner chamber of the mold body (10) can be divided and separated into an upper chamber (101) in which the plating solution (3) is contained by the ion-permeable membrane (120) acting as a diaphragm as shown in FIG. 3a, and a lower chamber (111) in which a space with an open bottom is formed. The above anode (20) may be placed in the upper chamber (101) of the mold body (10) in which the plating solution (3) is received, and although not shown in the drawing, it is connected to the positive (+) terminal of an external power supply to receive a positive potential. The above positive electrode (20) is electrically connected to the positive electrode busbar (400) through a shaft (410) penetrating the mold body (10), and can be connected to the positive (+) electrode of