What causes tombstoning and why is it a problem?
Tombstoning occurs when a small component flips up during the reflow process. This issue is linked to thermal differences from the pad resulting in one reflowing before the other. Other causes include uneven solder paste application, improper pad designs, and ground plane circuit board design. This is a major problem because it creates a disconnection on the PCB.
HOW TO PREVENT TOMBSTONING
- Use anti-tombstoning solder paste
- Change up your reflow profile
Consider a longer soak time or reducing the ramp rate
- Modify the stencil design
Equalize solder paste deposit in trouble spots