The Effect of Solder Paste Volume and Reflow Ambient Atmosphere on Reliability of CBGA Assemblies

Abstract

To investigate the effect of stencil thickness and reflow ambient atmosphere on the reliability of ceramic ball grid array (CBGA) assemblies, three levels of stencil thickness, 0.10, 0.15, and 0.20 mm, were used to print solder paste on printed circuit board (PCB). After the CBGA modules were placed on PCBs, the specimens were divided into two groups, and reflowed in nitrogen and compressed air separately. Properties of the six groups of assemblies, such as shear strength, bending fatigue life, thermal shock cycles, and vibration fatigue life, were tested to find out the optimum assembling process. The results show that assemblies prepared with a stencil 0.15 mm thick yield maximized performance. And the nitrogen ambient atmosphere demonstrates a remarkable effect on improving the fatigue life. Theoretical models are given to qualitatively explain the relationship between the solder joint volume and performance. This work provides a guideline on how to determine the soldering process parameters of CBGA assemblies.

Investigation Of The Effects Of Reflow Profile Parameters On Lead-free Solder Bump Volumes And Joint Integrity

“…Quality reflow soldering of surfacemount components is a major factor in reliable performance of electronic device. Many studies [3,4,5,6] have been conducted in this area but none seem to have really focused on the effect of reflow profile parameters on lead-free solder bump formation and associated solder joint integrity. Hitherto, electronic products' reliability has not been of critical concern and thus the common current practice has been the use of a single generic oven recipe for a family of (similar) products [1], or the reflowing of solder joints with a reflow feature ranges specified by the paste manufacturer.…”

Aoi Based Neurofuzzy System to Evaluate Solder Joint Quality

“…Therefore, a reliable inspection technique is required to examine solder joints in a PCB assembly. For this aim, several automated non-destructive inspection techniques like Automated X-ray Inspection (AXI), Automated Laser Inspection (ALI) and Automated Optical Inspection (AOI) have been proposed (Manjeshwar, 2006;Teramoto, 2007;Wu, 2001;Zhang, 2006;Hsu-Nan, 2006).…”

“…Nevertheless the X-ray-based techniques are not suitable for in-line inspection because of their low throughput and the complicated algorithms used for image interpretation (Manjeshwar, 2006;Teramoto, 2007). On the contrary, systems based on ALI methods can be used for 3D reconstruction or vibration analysis (Wu, 2001;Zhang, 2006). Solutions performing the first target showed effective, but slow measurement speed and the need of high-precision motion control are required.…”

Full-Field 3-D Measurement of Solder Pastes Using LCD-Based Phase Shifting Techniques

“…Such defects need three-dimensional (3D) measurement of surface profiles and the volume of the solder pastes. As the leads of SMT components become dense, 3D measurement will become more and more important in the quality inspection of solder pastes [4,9,10].…”

“…Three dimensional measurement of deposited solder pastes not only can detect the 3D defects, but also can improve the stencil printing process with feedback volume information [11,12]. Currently, nondestructive 3D measurement of deposited solder pastes is mainly performed by laser scanning systems [9][10][11][12][13][14][15][16]. These systems first project a laser line onto solder pastes and detect light reflection with optical sensors.…”