Direct die solder of gallium arsenide integrated circuit dies and methods of manufacturing gallium arsenide wafers
First Claim
Patent Images
1. An electronic circuit device comprising:
- a substrate;
a die attach pad located on the substrate;
a GaAs integrated circuit die having a copper backside contact pad and having a footprint of approximately the same size as the die attach pad, the GaAs integrated circuit die being connected to the die attach pad by a solder layer, the solder layer being disposed between the copper backside contact pad and the die attach pad on the substrate in a manner such that the GaAs integrated circuit die self-aligns with the die attach pad after reflow of the solder layer; and
a barrier layer formed from nickel and a palladium flash layer, said barrier layer being disposed between said copper backside contact pad and said solder layer.
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Accused Products
Abstract
Electronic devices, and methods of manufacturing the electronic devices, utilizing direct die soldering of GaAs integrated circuit dies. In some embodiments, the GaAs integrated circuit die can have a footprint approximately the same size as a die attach pad. Further, the GaAs integrated circuit die can self-align with the die attach pad after reflow of any solder layer used to attach the die.
68 Citations
14 Claims
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1. An electronic circuit device comprising:
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a substrate; a die attach pad located on the substrate; a GaAs integrated circuit die having a copper backside contact pad and having a footprint of approximately the same size as the die attach pad, the GaAs integrated circuit die being connected to the die attach pad by a solder layer, the solder layer being disposed between the copper backside contact pad and the die attach pad on the substrate in a manner such that the GaAs integrated circuit die self-aligns with the die attach pad after reflow of the solder layer; and a barrier layer formed from nickel and a palladium flash layer, said barrier layer being disposed between said copper backside contact pad and said solder layer. - View Dependent Claims (2, 3, 4, 5)
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6. A method for manufacturing a GaAs wafer assembly, said method comprising:
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fabricating a GaAs wafer having a copper layer over a backside of the wafer; electroless plating a barrier layer over said copper layer; forming a palladium flash layer over the copper layer; forming at least one singulated die from said GaAs wafer; and direct die soldering said at least one singulated die to a die attach pad on a substrate such that a solder layer is formed between the at least one singulated die and the die attach pad, the soldering performed in a manner such that the at least one singulated die self-aligns with the die attach pad after reflow of the solder layer. - View Dependent Claims (7, 8, 9, 10, 11)
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12. An electronic circuit module comprising:
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a singulated GaAs integrated circuit die having a copper contact pad; a printed circuit board having a die attach pad, said die attach pad sized to receive the singulated GaAs integrated circuit die and having a footprint of approximately the same size as the singulated GaAs integrated circuit die; a solder layer disposed between said copper contact pad of the die and said die attach pad of the printed circuit board, said copper contact pad of the singulated GaAs integrated circuit die attached to said die attach pad of the printed circuit board in a manner such that the singulated GaAs integrated circuit die self-aligns with the die attach pad after reflow of the solder layer; a nickel layer, said nickel layer formed between said copper contact pad and said solder layer; and a flash palladium layer, said flash palladium layer formed between said nickel layer and said copper contact pad and configured to act as a wetting layer for the solder layer. - View Dependent Claims (13, 14)
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Specification