Printed circuit board mounted with electric elements thereon
AssigneeNEC Corporation
InventorJoji Kawaguchi
Life of this patent
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Abstract
Electric elements such as a resistance chip, a capacitor chip, a semiconductor device package, and a connector are mounted on a printed circuit board by using at least two methods selected from the re-flow method using cream solder, the chip-on board method using bonding wires, the outer lead bonding method, and the thermal pressing method using heat-seal. The printed circuit board is provided with lands having surface layers of a non-electrolysis Ni--Au plate, a soft Au plate and an electrolysis solder plate, each corresponding to a selected mounting method.
Claims4
A printed circuit board comprising lands for mounting electric elements on said printed circuit board, said lands having a structure dependent upon which of a plurality of methods is used to mount electric elements on said printed circuit board;
- said lands having a structure comprising a predetermined pattern of a copper foil covered by a non-electrolysis Ni--Au plate when a re-flow method using cream solder is used, or a thermal pressing method is used;
- said lands having a structure comprising said predetermined pattern of a copper foil covered by said non-electrolysis Ni--Au plate, said non-electrolysis Ni--Au plate being in turn covered by an electrolysis solder plate when an outer lead bonding method is used to mount a tape carrier package;
- said lands having a structure comprising said predetermined pattern of a copper foil covered by said non-electrolysis Ni--Au plate, said non-electrolysis Ni--Au plate being covered in turn by a soft Au plate when a chip onboard method is used to mount said electric elements on said printed circuit board.
A printed circuit board comprising:
- printed electric circuits formed with a predetermined pattern on said printed circuit board;
- and
- lands provided on said printed circuit board, said lands being connected to said printed electric circuit, and comprising a land having a non-electrolysis Ni--Au plate surface layer to be used for a re-flow and thermal pressing methods to mount electric elements on said printed circuit board, a land having a soft Au plate surface layer to be used for a chip onboard method to mount electric circuit elements on said printed board, and a land having an electrolysis solder plate surface layer to be used for an outer lead bonding method to mount electric elements on said printed circuit board.
A method of fabricating a printed circuit board comprising lands for mounting a plurality of electric elements on said printed circuit board, said lands comprising a predetermined pattern of a copper foil covered by a non-electrolysis Ni--Au plate, said method comprising the steps of:
- covering said non-electrolysis Ni--Au plate of some of said lands with an electrolysis solder plate surface layer to allow a tape carrier package to be mounted by a local re-flow method on said lands covered by said electrolysis solder plate;
- covering said non-electrolysis Ni--Au plate of some of said lands with a soft Au plate surface layer to allow said electric elements to be mounted by a chip onboard method on said soft Au plate surface layer covered lands using bonding wires;
- mounting some of said plurality of electric elements on some of said lands covered by said non-electrolysis Ni--Au plate surface layer by a local re-flow method using cream solder;
- and
- mounting some of said plurality of electric elements on some of said lands covered by said non-electrolysis Ni--Au plate surface layer by a thermal pressing method providing heat seal.
Dependencies are inferred from the claim text.