Ball grid array assembly using a solder paste mix and method of using a solder paste dip
A method for manufacturing a ball grid array (BGA) assembly is disclosed. An example method may include coating at least a portion of each solder ball of a BGA in a solder paste mix. The method may further include mounting the BGA onto a secondary board to form the BGA assembly, wherein mounting the BGA on the secondary board comprises mounting each solder ball coated with the solder paste mix to the secondary board.
1 . A method for manufacturing a ball grid array (BGA) assembly, the method comprising:
coating at least a portion of each solder ball of a BGA in a solder paste mix, wherein the BGA comprises a plurality of solder balls, and wherein the solder paste mix comprises solder paste, wherein coating at least the portion of each solder ball of the BGA in the solder paste mix comprises applying an application force to the BGA when lowered into the solder paste mix and the BGA is at least one of rotated, swirled, vibrated, and perturbed to increase solder paste mix coverage on the plurality of solder balls; and
mounting the plurality of solder balls onto a secondary board to form the BGA assembly, wherein mounting the plurality of solder balls onto the secondary board comprises mounting each solder ball coated with the solder paste mix to the secondary board, wherein the secondary board comprises a plurality of landing pads, wherein the plurality of solder balls coated with the solder paste mix are mounted to the plurality of landing pads, and wherein the landing pads are absent of the solder paste mix before the solder balls coated with the solder paste mix are mounted to the plurality of landing pads.
2 . The method of claim 1 wherein the solder paste mix comprises a different solder paste material than a solder paste used to form a plurality of solder joints between the solder balls and a die.
3 . The method of claim 1 , wherein coating at least the portion of each solder ball further comprises dipping the solder balls of the BGA into a solder paste mix reservoir configured to support the solder paste mix.
4 . The method of claim 3 , wherein lowering the BGA further comprises lowering the BGA to an application depth within the solder paste mix reservoir.
5 . The method of claim 4 , wherein the BGA is lowered substantially parallel with respect to a bottom surface of the solder paste mix reservoir.
6 . The method of claim 3 , wherein the application force comprises at least a controlled acceleration.
7 . The method of claim 3 , the method further comprising rotating the solder paste mix reservoir about an axis once the BGA is removed, wherein the rotation of the solder paste mix reservoir causes the solder paste mix to interact with a leveling arm and the leveling arm causes the solder paste mix to redistribute such that the solder paste mix has a substantially uniform surface profile.
8 . The method of claim 7 , the method further comprising lowering the leveling arm into an interaction configuration such that the leveling arm is positioned at an interaction height above a bottom of the solder paste mix reservoir.
9 . The method of claim 1 , the method further comprising heating the BGA assembly to a temperature above a melting temperature of the solder paste mix, wherein the solder paste mix reflows on a respective solder ball to form a solder joint.
10 . The method of claim 9 , the method further comprising maintaining the temperature above the melting temperature of the solder paste mix for a dwell time period.
11 . The method of claim 9 , wherein the solder joint is directly coupled to a landing pad of the secondary board.
12 . The method of claim 9 , the method further comprising cooling the BGA assembly to solidify the solder paste mix.
13 . The method of claim 1 , wherein the secondary board comprises a plurality of landing pads and mounting the BGA further comprises aligning each solder ball to a landing pad of the plurality of landing pads.
14 . The method of claim 1 , wherein the solder paste mix comprises a type 3 and/or type 4 solder paste.
15 . The method of claim 1 , wherein the solder paste mix comprises a type 5 solder paste.
16 . The method of claim 1 , wherein the plurality of solder balls have a pitch of approximately 300 micrometers (μm) or greater.
17 . The method of claim 1 , wherein the plurality of solder balls have a height of approximately 150 micrometers (μm) or greater.
18 . The method of claim 1 , wherein coating at least the portion of each solder ball of the BGA in the solder paste mix comprises applying the application force to the BGA when lowered into the solder paste mix and the BGA is rotated to increase solder paste mix coverage on the plurality of solder balls.
19 . The method of claim 1 , wherein coating at least the portion of each solder ball of the BGA in the solder paste mix comprises applying the application force to the BGA when lowered into the solder paste mix and the BGA is swirled to increase solder paste mix coverage on the plurality of solder balls.
20 . The method of claim 1 , wherein coating at least the portion of each solder ball of the BGA in the solder paste mix comprises applying the application force to the BGA when lowered into the solder paste mix and the BGA is vibrated to increase solder paste mix coverage on the plurality of solder balls.