SOLDER BUMP FORMATION ON A CIRCUIT BOARD USING A TRANSFER SHEET

Title:

SOLDER BUMP FORMATION ON A CIRCUIT BOARD USING A TRANSFER SHEET

Document Type and Number:

WIPO Patent Application WO/2010/093031

Kind Code:

A1

Abstract:

A method of using a solder transfer sheet, which does not require position alignment, to form solder bumps on electrodes of a printed circuit board without forming a bridge. The solder transfer sheet comprises a support base on at least one surface of which a solder layer is deposited. The method includes overlaying the solder transfer sheet on the circuit board, heating, under pressure, to a temperature lower than the solidus temperature of the solder to selectively bond the solder layer to the electrodes by means of solid phase diffusion bonding, and peeling the transfer sheet from the circuit board. The solder layer may be a layer formed from a continuous solder film or one layer of solder particles deposited on the support base by an adhesive layer.

Inventors:

KURAMOTO TAKEO (JP)
TSURUTA KAICHI (JP)
SAITOU TAKEO (JP)

Application Number:

PCT/JP2010/052137

Publication Date:

August 19, 2010

Filing Date:

February 15, 2010

Export Citation:

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Assignee:

SENJU METAL INDUSTRY CO (JP)
KURAMOTO TAKEO (JP)
TSURUTA KAICHI (JP)
SAITOU TAKEO (JP)

International Classes:

B23K1/20; H05K3/34; B23K3/06; H01L21/60

Domestic Patent References:

WO2006067827A1

2006-06-29

Foreign References:

JPH07336033A	1995-12-22
JP2001319949A	2001-11-16

Other References: