Abstract:
The electrical contacts, such as ball grid array (BGA) solder balls, of an integrated circuit (IC) are coupled to printed circuit board (PCB) bonding pads that include vias. According to an embodiment of an electronic assembly, the vias are formed off-center, so as to inhibit bridging between adjacent solder balls during a solder reflow operation by minimizing the effect of solder ball ballooning resulting from outgassing of a thermally expansive substance, such as a volatile organic compound (VOC) from the via channels. The bonding pads are separated into two groups, each having vias offset in a different direction, so that asymmetric surface tension forces in the molten solder during a solder reflow operation do not cause the IC to slide to one side. A substrate, an electronic assembly, an electronic system, and fabrication methods are also described.
Abstract:
An interconnection structure for coupling conductive layers of a circuit board includes a pin configured to be press-fitted in an aperture traversing the circuit board, to electrically couple the conductive traces. The pin may be placed in a predrilled aperture, or driven into the circuit board, forming the aperture thereby. The pin may also be configured as a punch, removing a plug of material as it is driven therethrough. The pin may comprise a capacitive or resistive region configured to capacitively or resistively couple the first and second traces. The pin may be configured such that capacitive or resistive values are selectable according to a depth to which the pin is positioned in the aperture. The pin may serve as an offset post for mounting the circuit board to a chassis. In such a case, the pin may be provided with a longitudinal aperture configured to receive a threaded screw.