dryjointed

Dryjointed is an adjective used in electronics to describe a solder joint that has formed improperly, resulting in a poor or nonexistent electrical connection. A dry joint, and by extension a board described as dryjointed, typically shows inadequate wetting of the pad and component lead, leaving a dull, cracked, or uneven fillet. This condition can cause intermittent connectivity or complete loss of signal.

Causes of dry joints include insufficient heat during soldering, oxidation on pads or leads, and residues from flux or contaminants. Poor solder alloy choice, incorrect soldering profile, excessive movement during cooling, or rework without proper cleaning can also contribute. Lead-free solders, while reliable when used correctly, can be more sensitive to improper heating, increasing the risk of dry joints if temperature control is poor.

Symptoms and impact vary from intermittent faults to permanent open circuits. Visually, joints may appear grey or grainy rather than shiny and smooth. Electrically, a dry joint may exhibit abnormally high resistance, voltage drop, or flaky performance, especially under vibration or thermal cycling.

Diagnosis typically involves visual inspection, continuity testing, and resistance measurements. In complex cases, especially with densely packed or hidden joints, X-ray or 3D inspection tools may be employed.

Remedies focus on proper rework: remove the defective joint, thoroughly clean the area, and reflow with appropriate flux and temperature profiles. Ensure good pad preparation, correct solder amount, and adequate heat to achieve reliable wetting. Prevention emphasizes validated process controls, quality flux, correct solder alloys, and tooling that minimizes movement during cooling. Dry joints are a common but avoidable fault in well-controlled manufacturing and repair environments.