Improved bonding pad design for fluxless flip chip bonding process and low fracture strength substrates

2002 ◽  
Author(s):  
R. Bonda ◽  
Y. Guo ◽  
J. Stafford ◽  
G. Swan
Keyword(s):  
Fracture Strength ◽  
Flip Chip ◽  
Bonding Process ◽  
Flip Chip Bonding

Investigation of Flip-Chip Bonding for MEMS Applications

2004 ◽  
Vol 126 (1) ◽  
pp. 48-51 ◽  
Author(s):  
W. Salalha ◽  
E. Zussman ◽  
P. Z. Bar-Yoseph
Keyword(s):  
Finite Element ◽  
Solder Joint ◽  
Flip Chip ◽  
Bond Number ◽  
Bonding Process ◽  
Mems Devices ◽  
Finite Element Analyses ◽  
Flip Chip Bonding ◽  
Solder Volume ◽  
Simulation Results

An investigation of the flip-chip bonding process for application in MEMS devices was carried out. Finite element analyses of axisymmetric and non-axisymmetric solder joint geometries were performed. It was found that in typical cases of MEMS devices in which the solder volume is small (Bo≪1, where Bo is the Bond number), the finite element solution of the axisymmetric solder joint is well approximated by a surface of revolution whose generating meridian is a circular arc. Experimental results of solder joints in flip-chip assembly were found to correlate well with simulation results.

scholarly journals Transfer of Tactile Sensors Using Stiction Effect Temporary Handling

Micromachines ◽  
2021 ◽  
Vol 12 (11) ◽  
pp. 1330
Author(s):  
Peng Zhong ◽  
Ke Sun ◽  
Chaoyue Zheng ◽  
Heng Yang ◽  
Xinxin Li
Keyword(s):  
Silicon Nitride ◽  
Flip Chip ◽  
Tactile Sensor ◽  
Bonding Process ◽  
Electrical Performance ◽  
Tactile Sensors ◽  
Release Process ◽  
Flip Chip Bonding ◽  
Process Reliability ◽  
Temporary Bonding

A novel method for transfer of tactile sensors using stiction effect temporary handling (SETH) is presented to simplify the microelectromechanical-system (MEMS)/CMOS integration process, improve the process reliability and electrical performance, and reduce material constriction. The structure of the tactile sensor and the reroute substrate were first manufactured separately. Following the release process, the stiction-contact structures, which are designed to protect the low-stress silicon nitride diaphragm of the tactile sensor and prevent the low-stress silicon nitride diaphragm from moving during the subsequent bonding process, are temporarily bonded to the substrate owing to the stiction effect. After the released tactile sensor is bonded to the reroute substrate by Au–Si eutectic flip-chip bonding, a pulling force perpendicular to the bonded die is applied to break away the temporary supported beam of the tactile sensor, and the tactile sensor is then successfully transferred to the reroute substrate. The size of the transferred tactile sensor is as small as 180 μm × 180 μm × 1.2 μm, and the force area of the tactile sensor is only 120 μm × 120 μm × 1.2 μm. The maximum misalignment of the flip-chip bonding process is approximately 1.5 μm. The tactile sensors are tested from 0 to 17.1 kPa when the power supply is 5 V, resulting in a sensitivity of 0.22 mV/V/kPa, 0.26 mV/V/kPa, 0.27 mV/V/kPa and 0.27 mV/V/kPa, separately. The stress caused by the Au–Si eutectic flip-chip bonding ranges from −5.83 to +5.54 kPa. The temporary bonding strength caused by stiction is calculated to be larger than 7.06 kPa and less than 22.31 kPa. The shear strength of the bonded test structure is approximately 30.74 MPa and the yield of the transferred tactile sensors is as high as 90%.

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