Lead-frame structure, lead-frame, surface mount electronic device and methods of producing same

A lead-frame structure having two faces and exposing a treated silver surface on at least one of said two faces, wherein said lead-frame structure comprises at least two lead-frame entities each one having two faces and wherein said lead-frame structure is made of:

• (i) a lead-frame body structure made of copper and having two main sides;
• (ii) at least one of said main sides being coated with a silver coating, so that said at least one of said main sides at least partially exposes an untreated silver surface;
• and
• (iii) said untreated silver surface on said at least one of said main sides further comprising a treatment layer obtained by electrolytically treating said untreated silver surface on said at least one of said main sides of said lead-frame body structure with a treatment solution containing at least one hydroxide compound selected from alkali metal hydroxides, alkaline earth metal hydroxides, ammonium hydroxides and mixtures thereof, wherein the lead-frame body structure is a cathode,
• characterized in that said at least one of said two faces of at least one of said at least two lead-frame entities either exclusively exposes said treated silver surface or
• that said at least one of said two faces of said at least one of said at least two lead-frame entities partially exposes said treated silver surface and partially exposes said copper surface, wherein, on each one of said two faces of each one of said at least two lead-frame entities which partially exposes said treated silver surface, the area of said copper surface is smaller than the area of said treated silver surface.

A lead-frame having two faces and exposing a treated silver surface on at least one of said two faces and wherein said lead-frame is made of:

• a lead-frame body made of copper and having two main sides;
• (ii) at least one of said main sides being coated with a silver coating, so that said at least one of said main sides at least partially exposes an untreated silver surface;
• and
• (iii) said untreated silver surface on said at least one of said main sides further comprising a treatment layer obtained by electrolytically treating said untreated silver surface on said at least one of said main sides of said lead-frame body with a treatment solution containing at least one hydroxide compound selected from alkali metal hydroxides, alkaline earth metal hydroxides, ammonium hydroxides and mixtures thereof, wherein the lead-frame body is a cathode,
• characterized in that said at least one of said two faces of said lead-frame either exclusively exposes said treated silver surface or
• that said at least one of said two faces of said lead-frame partially exposes said treated silver surface and partially exposes said copper surface, wherein, on each one of said two faces of said lead-frame, the area of said copper surface is smaller than the area of said treated silver surface.

A surface mount electronic device, comprising:

• (A) a lead-frame having two faces and exposing a treated silver surface on at least one of said two faces of said lead-frame, wherein said lead-frame is made of:
• (i) a lead-frame body made of copper and having two main sides;
• (ii) at least one of said main sides being coated with a silver coating, so that said at least one of said main sides at least partially exposes an untreated silver surface;
• and
• (iii) said untreated silver surface on said at least one of said main sides further comprising a treatment layer obtained by electrolytically treating said untreated silver surface with a treatment solution containing at least one hydroxide compound selected from alkali metal hydroxides, alkaline earth metal hydroxides, ammonium hydroxides and mixtures thereof, wherein the lead-frame body is a cathode;
• and
• (B) at least one semiconductor device which is mounted on said at least one of said two faces of said lead-frame which exposes said treated silver surface, wherein said at least one semiconductor device is bonded to said treated silver surface on said at least one of said two faces of said lead-frame, wherein said bond creates an electrical connection between said lead-frame and said at least one semiconductor device,
• wherein said at least one semiconductor device and said lead-frame are together encapsulated with a resin material,
• characterized in that said at least one of said two faces of said lead-frame either exclusively exposes said treated silver surface or
• that said at least one of said two faces of said lead-frame partially exposes said treated silver surface and partially exposes said copper surface, wherein, on each one of said two faces of said lead-frame which partially exposes said treated silver surface, the area of said copper surface is smaller than the area of said treated silver surface.