X-ray Determination of Common Defects and Countermeasures: Insufficient Solder Penetration (Shallow Fill): Increase preheat, adjust wave contact angle and time, optimize hole wall cleanliness. Internal Voids/Gas Entrapment: Reduce solder gas content, optimize flux volatilization path and nitrogen protection. Eccentric Wetting: Check pin centering and fixture positioning, perform hole chamfering/expand ring width if necessary.

X-rays possess extremely strong penetrating power. Different material densities and thicknesses absorb X-rays to varying degrees. By analyzing the intensity changes of X-rays after passing through a sample, grayscale contrast images are formed to identify internal structures. Based on material density characteristics, PCBA components can be divided into four categories: tin-lead alloy solder joints (high density, appear dark in images); metal packaging shells, ceramic packaging, chips (medium density); plastic packaging materials, silicon materials (low density, appear light in images); void, crack defects and PCB vias (X-rays pass through completely, appear brightest).