The ionizing total dose delivered to semiconductor devicespackaged in leadless chip carriers in-place on a surface-mounttechnology (SMT) module during exposure to X-rays from X-raylaminography inspection techniques was determined. Laminography is anX-ray imaging technique that uses slices of the region of interest forsubsequent image analysis by computer software algorithms. Thehigh-speed, automated image analysis has been reported to result in muchlower ionizing dose than that of conventional radiography. The authorsdiscuss the dosimetry, radiation-absorbed dose dosimetry-calibrationtechniques, total dose profiles for integrated circuits (ICs) mounted onone type of SMT modules, and module design considerations resulting inmaximum exposure to ICs. Design conditions that result in high totaldose deposited in ICs when exposed to X-ray laminography have beenidentified. The conditions occur when small packages are placed in adense layout, on a double-sided printed wiring assembly design, withsolder joints on one side in line with ICs on the other
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