In testing with a clamshell fixture, what is the minimum square land required?

In testing with a clamshell fixture, what is the minimum square land required?

• A. 36 mils (0.9 mm)
• B. 18 mils (0.45 mm)
• C. 72 mils (1.8 mm)
• D. 50 mils (1.3 mm)

Answer: (A)

When you’re testing with a clamshell fixture, you need enough land area for the pogo pin to make a stable, reliable contact despite small misalignments and variations in plating and manufacturing. A square land of about 0.9 mm per side (36 mils) provides sufficient contact surface for the pin tip and clamps, helping avoid intermittent connections or missed contacts that can happen with smaller lands. Lands smaller than this are prone to unreliable contact, while larger lands aren’t necessary for achieving a minimum reliable contact and can waste board space or cause clearance issues. So, 36 mils (0.9 mm) is the minimum square land that supports dependable clamshell testing.

When you’re testing with a clamshell fixture, you need enough land area for the pogo pin to make a stable, reliable contact despite small misalignments and variations in plating and manufacturing. A square land of about 0.9 mm per side (36 mils) provides sufficient contact surface for the pin tip and clamps, helping avoid intermittent connections or missed contacts that can happen with smaller lands. Lands smaller than this are prone to unreliable contact, while larger lands aren’t necessary for achieving a minimum reliable contact and can waste board space or cause clearance issues. So, 36 mils (0.9 mm) is the minimum square land that supports dependable clamshell testing.