Ceramic substrate, and method of manufacturing the same

Patent metadata

Field	Value
Publication number	US-9338897-B2
Application number	US-201314133238-A
Country	US
Kind code	B2
Filing date	Dec 18, 2013
Priority date	Dec 19, 2012
Publication date	May 10, 2016
Grant date	May 10, 2016

Abstract

A ceramic substrate is provided that includes a ceramic substrate main body including a principal surface, a connecting terminal portion disposed on the principal surface of the ceramic substrate main body that is capable of being connected to another component via solder, the connecting terminal portion including a copper layer and a coating metal layer covering a surface of the copper layer; a contact layer of titanium or chromium disposed between the ceramic substrate main body and the connecting terminal portion; and an intermediate layer disposed between the copper layer of the connecting terminal portion and the contact layer, the intermediate layer including one of a titanium-tungsten alloy, a nickel-chromium alloy, tungsten, palladium, and molybdenum. The contact layer and the intermediate layer are set back from a side surface of the copper layer in a substrate plane direction.

First claim

What is claimed is:

1. A ceramic substrate comprising:
a ceramic substrate main body including a principal surface;
a connecting terminal portion disposed on the principal surface of the ceramic substrate main body for connecting to a component via solder, the connecting terminal portion including a copper layer and a coating metal layer covering a surface of the copper layer;
a contact layer of titanium or chromium disposed between the ceramic substrate main body and the connecting terminal portion;
an intermediate layer disposed between the copper layer of the connecting terminal portion and the contact layer, the intermediate layer including one of a titanium-tungsten alloy, a nickel-chromium alloy, tungsten, palladium, and molybdenum; and
a metallized metal layer disposed on the principal surface of the ceramic substrate main body, wherein
the contact layer and the intermediate layer are set back from a side surface of the copper layer in a substrate plane direction;
the metallized metal layer is coated with a protection layer for protecting from an etching solution for etching the contact layer; and
at least a portion of the contact layer is formed on the protection layer.

2. The ceramic substrate according to claim 1 , wherein
a part of the metallized metal layer coated with the protection layer is extended from a projected area of the connecting terminal portion.

3. The ceramic substrate according to claim 1 , further comprising:
an end-face through-hole conductor including a metallized metal and disposed on a side surface of the ceramic substrate main body, wherein
a surface of the end-face through-hole conductor is coated with the protection layer.

4. The ceramic substrate according to claim 1 , wherein the coating metal layer includes at least nickel.

5. The ceramic substrate according to claim 1 , wherein the coating metal layer includes nickel and gold or includes nickel, palladium, and gold.

6. A method of manufacturing the ceramic substrate according to claim 1 , the method comprising:
a firing step of forming the ceramic substrate main body and the metallized metal layer;
a protection layer-forming step of forming the protection layer by performing nickel plating on the metallized metal layer exposed on the principal surface side of the ceramic substrate main body;
a contact layer-forming step of forming the contact layer on a surface of the protection layer and on the principal surface of the ceramic substrate main body;
an intermediate layer-forming step of forming the intermediate layer on a surface of the contact layer;
a copper layer-forming step of forming the copper layer of the connecting terminal portion on a surface of the intermediate layer by copper plating;
an etching step of removing the intermediate layer and the contact layer that are exposed on the principal surface side of the ceramic substrate main body in a stepwise manner or simultaneously by etching, while protecting the metallized metal layer from corrosion due to an etching solution by the protection layer; and
a coating metal layer-forming step of forming the coating metal layer on the surface of the copper layer by successively performing nickel and gold plating, or nickel, palladium, and gold plating.

Assignees

• Ngk Spark Plug Co

Inventors

• Otsuka Yuma
• Fukunaga Kazunori
• Uchida Atsushi
• Yoshimura Kouhei

Classifications

• H05K2203/1461

  Applying or finishing the circuit pattern after another process, e.g. after filling of vias with conductive paste, after making printed resistors · CPC title

• H05K1/0306

  Inorganic insulating substrates, e.g. ceramic, glass · CPC title

• H05K2203/1338

  Chemical vapour deposition · CPC title

• H05K3/388

  by the use of a metallic or inorganic thin film adhesion layer · CPC title

• H05K3/4007 Primary

  Surface contacts, e.g. bumps (H05K3/4092 takes precedence; deposition of finish layers on pads H05K3/24; forming solder bumps H05K3/3465) · CPC title