BGA Bump Alloys

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Hi Was wondering what the general take is with reflow profi... - Nov 08, 2023 by processman

Your reflow profile should be designed towards the flux in y... - Nov 13, 2023 by Evtimov

processman

#90208

BGA Bump Alloys | 8 November, 2023

Hi Was wondering what the general take is with reflow profiles to take into account differing solder paste alloy compared to the solder alloy used for the bumps of a bga device. For instance, SAC305 solder paste and BGA device with SAC105 (higher melting point ) bumps. To ensure proper ball collapse and homogeneous solder joint. Would the main factor be peak reflow temp, TAL or both ?

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Evtimov

#90216

BGA Bump Alloys | 13 November, 2023

Your reflow profile should be designed towards the flux in your solder paste. To form a proper inter-metallic layer, you need to reach 20-30C above your melting point and stay in liquidus state for certain amount of time. SAC 105 has 3C difference from SAC 305, so not sure how much investigation about compatibility is needed.

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