Method to improve ball grid array Imax distribution for small form factor package design

Maximum current (Imax) distribution across substrate has been one of the major design factors that govern the electronic package form factor. Particularly on ball grid array (BGA) package design, often times Imax distribution determines the number of solder balls required for each interface to sustain respective workloads hence defines the total ball count and the x-y dimension of the electronic package. This paper introduces a new method to improve BGA Imax distribution while keeping ball count minimal for to enable small form-factor package design. The proposed solution utilizes fundamental of electrical resistance control through on-board BGA pad design customization to achieve more uniform Imax distribution across solder balls and enable up-to 25% Imax reduction with negligible IR drop impact. Power losses across plane were also simulated and compared against conventional design in this study.