Chip on board and heat sink attachment methods

A method for encapsulating a chip scale semiconductor package having a surface, a substrate, and a heat sink having a surface comprising:

• applying a layer of material as a mask to a portion of said surface of said chip scale semiconductor package;
• applying an encapsulant material to the remaining portion of said surface of said chip scale semiconductor package;
• removing said layer of material from said surface of said chip scale semiconductor package said removing including peeling said layer from said surface of said semiconductor die;
• bonding said chip scale package to said substrate;
• and securing said heat sink to said surface of said chip scale semiconductor package.

A method for applying a glob top material to a semiconductor die having a surface and a heat sink having a surface comprising:

• applying a first layer of material to said surface of said semiconductor die;
• applying a second layer of material as a mask to a portion of said surface of said first layer of material;
• applying an encapsulant material to the remaining portion of said surface of said semiconductor die;
• removing said layer of material from said surface of said semiconductor die said removing including peeling said layer from said surface of said semiconductor die;
• and
• securing said heat sink to a surface of said second layer of material.

A method for applying a glob top material to a surface of a semiconductor die having a heat sink having a surface comprising:

• applying a layer of material as a mask to a portion of said surface of said semiconductor die;
• applying glob top material to the remaining portion of said surface of said semiconductor die;
• removing said layer of material from said surface of said semiconductor die, said removing including peeling said layer from said surface of said semiconductor die;
• and
• securing said heat sink to said surface of said semiconductor die.

A method packing a portion of a Chip On Board semiconductor device having a heat sink, said method comprising:

• providing a semiconductor die having a first side, a second side, and a plurality of edges providing a substrate;
• providing a thermally conductive heat sink member;
• attaching the first side of said semiconductor die to said substrate;
• covering at least a portion of the second side of said semiconductor die with a material having an exposed surface;
• applying a material to encapsulate said edges of said semiconductor die;
• maintaining said exposed surface of said material covering at least a portion of the second side of said semiconductor die substantially unencapsulated;
• removing said material having an exposed surface covering at least a portion of the second side of said semiconductor die, said removing including peeling said material from said surface of said semiconductor die;
• and
• attaching said heat sink member to the second side of said semiconductor die.

A method for applying a glob top material to a surface of a semiconductor die having a heat sink having a surface comprising:

• applying a layer of gel elastomer material as a mask to a portion of said surface of said semiconductor die;
• applying glob top material to the remaining portion of said surface of said semiconductor die;
• peeling said gel elastomer material from said surface of said semiconductor die;
• and
• attaching said surface of said heat sink to said surface of said semiconductor die.

A method for forming a Chip On Board semiconductor device having a heat sink member and a substrate having electrical connections, said method comprising:

• providing a semiconductor die having a first side, a second side, a plurality of edges, and electrical terminals;
• attaching the first side of said semiconductor die to said substrate;
• connecting said electrical terminals of said semiconductor die to said electrical connections of said substrate;
• covering at least a portion of the second side of said semiconductor die with a compliant protective layer having an exposed surface;
• applying a material to encapsulate said electrical terminals and die edges;
• maintaining said exposed surface of said protective layer substantially unencapsulated by said material;
• removing said protective layer, said removing including peeling said protective layer;
• and
• attaching said heat sink member to the second side of said semiconductor die.

A method for forming a semiconductor device assembly having a heat sink, having semiconductor die having a first side, second side, and a plurality of edges, and having a substrate, said method comprising:

• attaching the first side of said semiconductor die to said substrate;
• covering at least a portion of the second side of said semiconductor die with a material having an exposed surface;
• applying a material to encapsulate said edges of said semiconductor die;
• maintaining said exposed surface of said material covering at least a portion of the second side of said semiconductor die substantially unencapsulated;
• removing said material having an exposed surface covering at least a portion of the second side of said semiconductor die, said removing said material including peeling said material away from the second surface of said semiconductor die;
• and
• attaching said heat sink member to the second side of said semiconductor die.