Method for welding an attachment piece to a semiconductor metallisation by laser welding
Various teachings of the present disclosure include a method for welding an attachment piece to a semiconductor metallization using laser welding. The method may include: arranging an attachment piece having a flat side with a thin point so the flat side faces the semiconductor metallization; and welding the flat side to the semiconductor metallization. The flat side rests against a flat side of the semiconductor metallization over an entire surface area of the flat side. The thin point is formed with a cup shape of the attachment piece. The cup shape is open in the direction away from the semiconductor metallization.
1 . A method for welding an attachment piece to a semiconductor metallization using laser welding, the method comprising:
arranging the attachment piece having a cup shape having a flat base with a thin point so the flat base faces the semiconductor metallization and an opening of the cup is closed by a cover in a direction away from the semiconductor metallization; and
welding the flat base to the semiconductor metallization by melting the cover with a laser so a resulting molten material from the cover wets the thin point;
wherein the flat base rests against a flat side of the semiconductor metallization over an entire surface area of the flat base.
2 . The method as claimed in claim 1 , wherein:
the semiconductor metallization has a metallization thickness; and
welding the flat side to the semiconductor metallization results in a welding-in depth during the laser welding of at most as deep as the metallization thickness.
3 . The method as claimed in claim 1 , wherein:
the thin point has a thin-point thickness perpendicular to the flat side of at most 100 micrometers.
4 . The method as claimed in claim 1 , wherein:
a defined air gap is provided between the attachment piece and the semiconductor metallization; and
welding the flat side is performed at the defined air gap.
5 . The method as claimed in claim 1 , wherein the cup shape of the attachment piece holds a vacuum.
6 . The method as claimed in claim 1 , wherein an air gap is retained between the attachment piece and the semiconductor metallization.
7 . The method as claimed in claim 1 , wherein welding the flat side includes using a laser light with a wavelength of at most 800 nanometers.
8 . The method as claimed in claim 1 , wherein the thin point has a smallest width of at least 5 micrometers and at most 1000 micrometers in directions along the flat side.
9 . The method as claimed in claim 1 , wherein the attachment piece comprises copper and/or solder and/or ceramic and/or polymer and/or forms a terminal contact.
10 . The method as claimed in claim 1 , further comprising forming a melt pool with a smallest width in a direction along the flat side for welding the flat side;
wherein a smallest width of the thin point is at least twice the smallest width of the melt pool.
11 . An electronics module comprising:
a semiconductor metallization; and
an attachment piece welded to the semiconductor metallization;
wherein the attachment piece has a cup shape with a flat base having a thin point facing the semiconductor metallization and an opening of the cup in a direction away from the semiconductor metallization; and
the flat base is welded to the semiconductor metallization;
the flat base rests against a flat side of the semiconductor metallization over an entire surface area of the flat base.