Two stage transfer molding method to encapsulate MMC module

A method for fabricating a semiconductor card comprising:

• providing a strip comprising a plurality of spaced-apart substrates, said strip comprising a plurality of peripheral openings defining said substrates and a plurality of connecting segments attaching said substrates to said strip, each substrate of said plurality having at least one circuit thereon and at least one connector;
• mounting a card circuit on each substrate of said plurality, each card circuit comprising at least one semiconductor component and means for communication between each said card circuit and an external circuit;
• providing a first molding assembly comprising a plurality of mold cavities for forming a first plastic casting over each circuit while leaving a peripheral portion of each substrate uncovered;
• molding said first plastic castings to said substrates using said first molding assembly;
• removing said strip from said first molding assembly;
• providing a second molding assembly comprising a plurality of mold cavities for forming a second plastic casting encapsulating said peripheral portions of said substrates;
• molding said second plastic castings to said substrates using said second molding assembly;
• removing said strip from said second molding assembly;
• and
• severing said connecting segments to singulate individual semiconductor cards from said strip.

A method of fabricating a card having a circuit side and a back side, said substrate generally separated from a surrounding frame by a peripheral opening spanned by at least one connecting segment between said substrate and said frame, said substrate having an electrical circuit and at least one external connector for communicating between said electrical circuit and an external circuit, said method comprising:

• clamping said substrate and frame between first and second plates of a first molding assembly;
• injecting a first material into a first mold cavity formed by said first and second plates to mold a first plastic casting onto said circuit side of said substrate and encapsulate said electrical circuit while leaving a peripheral portion of said circuit side uncovered, said first plastic casting having an exposed surface;
• removing said frame, substrate and first plastic casting from said first molding assembly,
• clamping said frame, substrate and first plastic casting between first and second plates of a second molding assembly, said exposed surface of said first plastic casting compressed for sealingly engaging said back side of said substrate against one of said first plate and said second plate of said second molding assembly;
• injecting a second material into a second mold cavity of said second molding assembly to mold a second plastic casting surrounding said first plastic casting and enclosing said uncovered peripheral portion and an edge of said substrate, said second plastic casting having a peripheral outer edge;
• and
• removing said frame, substrate and first and second plastic castings from said second molding assembly.

A method for fabricating a card comprising:

• providing a substrate having a circuit side and a back side, said substrate having a first portion thereof having a peripheral edge separated from a second portion of said substrate by a peripheral opening spanned by at least one connecting segment between said first portion of said substrate and said second portion of said substrate;
• placing said substrate between a first plate and a second plate of a first molding assembly, said first plate and said second plate forming a first mold cavity;
• injecting a first material into said first mold cavity for molding a first plastic casting onto at least a portion of said circuit side of the substrate and leaving a peripheral portion of said circuit side free of said first material, said first plastic casting having an exposed surface;
• placing said second portion of said substrate and said first plastic casting between a first plate and a second plate of a second molding assembly with at least a portion of said back side of said substrate engaging a portion of said first plate of said second molding assembly, said first plate and said second plate of said second molding assembly forming a second mold cavity;
• and
• injecting a second material into said second mold cavity for molding a second plastic casting surrounding said first plastic casting and enclosing said peripheral edge of said first portion of said substrate, said second plastic casting having a peripheral outer edge.