Method for manufacturing a surface mount technology (SMT) pad structure for next generation speeds
A method for manufacturing a surface mount technology (SMT) pad structure includes attaching an adjacent pair of differential contact strips to a nonconductive surface of respective landing pads of a surface mount technology (SMT) pad structure of a circuit board substrate, the pair of differential contact strips having converging narrowing at a respective distal end and each having a proximal signal trace for conducting a high-speed communication signal to another functional component attached to a circuit board substrate. The method includes attaching a return current strip that is longitudinally aligned adjacent to the pair of differential contact strips on a first lateral side and connected to a ground plane of the circuit board substrate, the converging narrowing of the adjacent differential contact strip increasing separation from a distal end of the return current strip, the separation improving signal integrity by reducing fringe effects, increasing impedance, and quenching resonance.
1. A method for manufacturing a surface mount technology (SMT) pad structure, the method comprising:
attaching an adjacent pair of differential contact strips to a nonconductive surface of respective landing pads of a surface mount technology (SMT) pad structure of a circuit board substrate, the pair of differential contact strips having converging narrowing at a respective distal end and each having a proximal signal trace for conducting a high-speed communication signal to another functional component attached to a circuit board substrate; and
attaching a return current strip that is longitudinally aligned adjacent to the pair of differential contact strips on a first lateral side and connected to a ground plane of the circuit board substrate, the converging narrowing of the adjacent differential contact strip increasing separation from a distal end of the return current strip, the separation improving signal integrity by reducing fringe effects, increasing impedance, and quenching resonance.
2. The method of claim 1 , further comprising:
attaching a surface mount device (SMD) having one or more connector pins that correspond to and are attached to the one or more landing pads to conduct the high-speed communication signal and forming a circuit board assembly of an information handling system.
3. The method of claim 1 , wherein the converging narrowing of each strip comprises a tapered end.
4. The method of claim 1 , wherein the converging narrowing of each strip comprises a rounded end.
5. The method of claim 1 , wherein a longitudinal length of the converging narrowing portion of each strip of the pair of differential contact strips is within a range of 30-50% of a total longitudinal length of the respective landing pad.
6. The method of claim 1 , further comprising attaching a next return current strip that is longitudinally aligned adjacent to the pair of differential contact strips on a second lateral side, the next return current strip connected to the ground plane of the circuit board substrate.
7. The method of claim 1 , further comprising:
attaching a metallic layer onto a surface of the circuit board substrate;
etching the metallic layer to leave the adjacent pair of differential contact strips and attaching a return current strip; and
attaching a raised rectangular ridge around the adjacent pair of differential contact strips to form the landing pad to guide the SMT connector pin of the SMD.
8. The method of claim 1 , wherein the converging narrowing of the adjacent differential contact strip ensures superior electrical performance for next generation speeds, while maintaining mechanical stability of the strip, decreases capacitive effect by the landing pads resulting in improved impedance, achieves better return loss and insertion loss, and mitigates crosstalk because of a differential property maintained at edges of the landing pads, and reduces electrical field density and results in superior electrical performance of the landing pads.
9. The method of claim 1 , wherein the converging narrowing to provide the tapered end provides a removal at the distal end of 14% of a contact area of each strip.
10. The method of claim 1 , wherein the converging narrowing to provide the rounded end provides a removal at the distal end of 8% of a contact area of each strip.
11. The method of claim 1 , wherein the converging narrowing provides a greater length of curved surface which reduces charge accumulation at each strip.
12. The method of claim 1 , wherein the converging narrowing of each strip comprises a tapered end that provides an increased impedance, which quenches any resonance by the converging, narrowing distal ends of the strip.
13. The method of claim 1 , wherein the converging narrowing of each strip comprises a rounded end that provides an increased impedance, which quenches any resonance by the converging, narrowing distal ends of the strip.
14. The method of claim 1 , further comprising a next return current strip that is longitudinally aligned adjacent to the pair of differential contact strips and on an opposite side to the return current strip, the next return current strip connected to the ground plane of the circuit board substrate, the return current strip and next return current strip extending on lateral sides of the pair of differential contact strips that are electrically connected as positive and negative values to a high communication speed functional component of the IHS.