Manufacturing method for attaching components to a substrate
AssigneeSaturn Electronics & Engineering, Inc.
InventorsTimothy Patterson, Alex Lim Tiang Hock
Life of this patent
Estimating the term…
Abstract
A method for manufacturing a chip assembly includes the steps of applying a controlled amount of flux to a plurality of solder balls on a die, applying a non-fluxing underfill material to a substrate, and assembling the die and substrate together to form the chip assembly such that the non-fluxing underfill material is trapped in between the die and the substrate. By applying the underfill material to the substrate before the chip is assembled rather than afterward, the inventive method increases chip assembly speed while maintaining control over flux application to prevent the solder balls from collapsing, eliminate the need for a defined solder resist window, and maintain a consistent die-to-substrate clearance at the solder joint.
Claims13
A method for connecting a die having at least one solder portion to a substrate including pads or traces, comprising the steps of:
- applying flux to at least one selected area of said at least on solder portion;
- applying an unhardened, deformable non-fluxing underfill material to a select area of said substrate;
- and
- moving the die toward the substrate via said at least one solder portion, wherein the unhardened deformable non-fluxing underfill is trapped between said solder portion of said die and said substrate to form a solder joint that encases a solder ball above said select area of said substrate to provide a solder joint with substantially consistent die-to-substrate clearance, the solder ball is in an uncollapsed condition prior to hardening of the underfill material and does not allow the die to contact the substrate, and the pads or traces do not collapse during assembly of the solder portion to the substrate.
A method for connecting a die having a plurality of solder balls to a substrate having a plurality of pads corresponding to said plurality of solder balls, comprising the steps of:
- applying flux to a selected area of each of said solder balls;
- applying a deformable, unhardened non-fluxing underfill material to said substrate;
- soldering the plurality of solder balls to the plurality of pads, wherein the deformable, unhardened non-fluxing underfill material is trapped in between the die and the substrate to form a solder joint with a substantially consistent die-to-substrate clearance, wherein the solder balls do not collapse upon the substrate;
- and
- curing the deformable non-fluxing underfill material that controls at least one of time and temperature.
Dependencies are inferred from the claim text.