Method for manufacturing a ceramic copper circuit board
View Patent ↗A ceramic copper circuit board according to an embodiment includes a ceramic substrate and a first copper part. The first copper part is bonded at a first surface of the ceramic substrate via a first brazing material part. The thickness of the first copper part is 0.6 mm or more. The side surface of the first copper part includes a first sloped portion. The width of the first sloped portion is not more than 0.5 times the thickness of the first copper part. The first brazing material part includes a first jutting portion jutting from the end portion of the first sloped portion. The length of the first jutting portion is not less than 0 μm and not more than 200 μm. The contact angle between the first jutting portion and the first sloped portion is 65° or less.
1. A method for manufacturing a ceramic copper circuit board, comprising:
preparing a ceramic substrate to have a first copper part and a second copper part bonded to a first surface of the ceramic substrate via a brazing material layer, the first copper part and the second copper part being separated from each other in a first direction along the first surface, a thickness of the first copper part and a thickness of the second copper part being 0.6 mm or more;
etching a portion of the brazing material layer positioned between the first copper part and the second copper part to form a first brazing material part positioned between the ceramic substrate and the first copper part, to form a second brazing material part positioned between the ceramic substrate and the second copper part, and to cause a distance between an end portion of the first brazing material part and an end portion of the first copper part to be 100 μm or less; and
etching the first copper part so that a side surface of the first copper part includes a first sloped portion, a length of a first jutting portion of the first brazing material part jutting from an end portion of the first sloped portion is not less than 0 μm and not more than 200 μm, a contact angle between the first sloped portion and the first jutting portion is 65° or less, and a width of the first sloped portion is not less than 0.5 times the thickness of the first copper part.
2. The method for manufacturing the ceramic copper circuit board according to claim 1 , wherein
the first copper part and the second copper part are formed by etching a copper plate bonded to the ceramic substrate via the brazing material layer.
3. The method for manufacturing the ceramic copper circuit board according to claim 1 , wherein
the first copper part is etched to cause the length of the first jutting portion to be greater than 0 μm and not more than 200 μm.
4. The method for manufacturing the ceramic copper circuit board according to claim 1 , wherein
the second copper part is etched simultaneously with the etching of the first copper part so that a side surface of the second copper part includes a second sloped portion facing the first sloped portion, a length of a second jutting portion of the second brazing material part jutting from an end portion of the second sloped portion is not less than 0 μm and not more than 200 μm, a contact angle between the second sloped portion and the second jutting portion is 65° or less, and a width of the second sloped portion is not less than 0.5 times the thickness of the second copper part.
5. The method for manufacturing the ceramic copper circuit board according to claim 1 , wherein
the first copper part is etched to cause the contact angle between the first sloped portion and the first jutting portion to be not less than 5° and not more than 60°.
6. The method for manufacturing the ceramic copper circuit board according to claim 1 , wherein
the first copper part is etched to cause an angle of an upper end portion of the first sloped portion to be 50° or more.
7. The method for manufacturing the ceramic copper circuit board according to claim 1 , wherein
the brazing material layer includes silver, copper, and an active metal.
8. The method for manufacturing the ceramic copper circuit board according to claim 1 , wherein
the thickness of the first copper part and the thickness of the second copper part are 0.8 mm or more, and
the ceramic substrate is a silicon nitride substrate having a thickness of 0.4 mm or less.