International Business Machines Corporation

Arthur L Leerssen

Issa S Mahmoud

Peter G Ledermann

Everitt W Mace

Gaston G Settle

John Reece

Raymond E Prime

Srini V Vasan

Charles T Randolph

Alvin D Nguyen

Phong T Truong

Methods and apparatus are provided for applying solder in precise amounts to fine pitch leads such as those suitable for direct chip attachment (DCA) or flip-chip applications by using a heated platen to apply pressure to solder overlaying a plurality of lands on circuitized substrate. In one embodiment paste solder screened through a mask having apertures each corresponding to a plurality of land locations. In another embodiment, a web of solder foil is accurately positioned over a plurality of fine pitch lands. In each embodiment, a heated platen includes at least one active element corresponding in size and shape to the area having a plurality of fine pitch lands. A third embodiment includes individual platens for lands to which solder is to be applied.

Fine pitch solder application

A nozzle assembly is shown for depositing solder onto a series of conductive surfaces such as the mounting pads of a surface mount integrated circuit board. The nozzle assembly includes an upper nozzle mount and a removeable nozzle head which has an interior bore for receiving a portion of the nozzle mount and an elongate heat source. The nozzle head also includes an orifice for receiving solid solder fed within the interior bore to contact the elongate heat source. The interior bore terminates in a solder reservoir for molten solder which is fed within the interior bore to contact the elongate heat source. The molten solder is dispensed through a tip opening to deposit uniform amounts of solder on each pad.

Solder placement nozzle assembly

Growing community of inventors

Austin, TX, United States of America

Arthur L Leerssen