SILVER LAYER FORMED BY ELECTROSILVERING SUBSTRATE MATERIAL

• US 20080006911A1
• Filed: 07/05/2007
• Published: 01/10/2008
• Est. Priority Date: 07/06/2006
• Status: Active Grant

• Current Assignee: Panasonic Electric Works Company Limited (Panasonic Holdings Corporation)
• Original Assignee: Asahi Matsushita Electric Works Ltd. (Panasonic Holdings Corporation)
• Inventors: IKEGAWA, Naoto, NAKAHARA, Youichiro
• Granted Patent: US 8,062,765 B2
• Time in Patent Office: Days
• US Class Current: 257/645
• CPC Class Codes: C25D 3/46 of silver
• CPC Class Codes: C25D 5/02 Electroplating of selected surface areas
• CPC Class Codes: C25D 5/10 Electroplating with more than one layer of the same or of different metals for bearings C25D7/10
• CPC Class Codes: C25D 5/50 by heat-treatment
• CPC Class Codes: C25D 5/617 Crystalline layers
• CPC Class Codes: C25D 5/627 Electroplating characterised by the visual appearance of the layers, e.g. colour, brightness or mat appearance
• CPC Class Codes: H01L 33/60 Reflective elements
• CPC Class Codes: Y10T 428/12882 Cu-base component alternative to Ag-, Au-, or Ni-base component
• CPC Class Codes: Y10T 428/12896 Ag-base component
• CPC Class Codes: Y10T 428/12993 Surface feature [e.g., rough, mirror]

Abstract

The inventors have conducted vigorous studies, and discovered as a result that it is possible to form a silver layer having a high reflectance of about 90 to 99% in a visible light are a by setting a grain size of an outermost surface of a silver plated layer within a range of 0.5 μm or more to 30 μm or less.

Claims

1. A silver layer formed by electrosilvering a substrate material,

wherein a grain size of an outermost surface is within a range of 0.5 μ

m or more to 30 μ

m or less.

2. The silver layer according to claim 1, wherein a silver plated layer has a film thickness of 1 μ

m or more, and the substrate material is copper.

3. The silver layer according to claim 1, wherein a silver plated layer has a film thickness of 4 pan or more, and the substrate material is nickel.

4. The silver layer according to claim 2, wherein surface roughness of the substrate material is 0.5 μ

m or more.

5. The silver layer according to claim 3, wherein the nickel contains no sulfur.

6. A method for manufacturing the silver layer according to claim 1, comprising the steps of:

heating the silver plated layer at a temperature of 200°

C. or more for 30 seconds or more after the electrosilvering.

7. A method for manufacturing the silver layer according to claim 1, comprising the steps of:

carrying out the electrosilvering by low-cyan bathing.

8. A LED mounted substrate comprising,

the silver layer according to claim 1 as a reflective surface.

9. A method for manufacturing the LED mounted substrate according to claim 8, comprising the steps of:

forming a conductive layer on a substrate surface;

patterning the conductive layer to form a circuit pattern;

forming a copper plated layer on the circuit pattern;

forming a nickel plated layer on the copper plated layer; and

forming a silver plated layer on the nickel plated layer.