Issue link: https://iconnect007.uberflip.com/i/1379105
38 SMT007 MAGAZINE I JUNE 2021 experienced in the field on electronic products from customers. Reviewing the various defect causes, it was found that around 25% of all case studies have been due to de-wetting issues. e follow- ing sections will review a series of case stud- ies related to de-wetting issues based on root cause analysis with input provided on counter- measures to prevent these defects based on the company's knowledge and experience in this area. ese case studies are related to inferior component/board plating quality, contami- nated plating on both the PCB as well as the component, foreign object debris (FOD) as a cause of the de-wetting of solder, damaged component plating and improper off-set solder paste printing. Experimental Electronic product from different custom- ers was analyzed. All five cases investigated showed solder de-wetting. e five different de-wetting case studies were classified into the following categories which are then discussed in further detail: 1. Inferior board plating/surface finish quality 2. Contaminated plating 3. Foreign object debris (FOD) 4. Damaged plating 5. Improper process condition setting Inferior board plating/surface finish quality (Case Study 1) Defect observed Solder de-wetting occurred on the pad sub- strate. e no-clean solder paste material sol- dered on the pad was Sn3Ag0.5Cu Type 4. Type of analysis equipment used to observe and characterize defect e surface and cross-sectional observation of the HAL (hot air solder level) board surface finish treatment was performed using an opti- cal microscope and a SEM (scanning electron microscope). e optical microscope used is shown in Figure 1. e SEM used is shown in Figure 2. Contaminated plating (Case Study 2) Defect observed Solder de-wetting occurred on the pad sub- strate. e no-clean solder paste material sol- dered on the pad was Sn3Ag0.5Cu Type 4. Type of analysis equipment used to observe and characterize defect SEM (scanning electron microscope) with EDX (energy dispersive X-ray) analysis and X-ray observation was performed on the pad substrate for both good and poor solder wet- ting. e X-ray equipment used is shown in Figure 3. Figure 1: Optical microscope. Figure 2: Scanning electron microscope.