The Effect of Laser Energy and Nitrogen Flow in Solder Joints Properties of Head Gimbal Assembly
Kittimeth Wattananaphakasem1, Ubolrat Wangrakdiskul2, Jakawat Deeying3

1Kittimeth Wattananaphakasem*, Production Engineering Department, Faculty of Engineering, King Mongkut’s University of Technology North Bangkok, Bangkok, Thailand.
2Ubolrat Wangrakdiskul, Production Engineering Department, Faculty of Engineering, King Mongkut’s University of Technology North Bangkok, Bangkok, Thailand.
3Jakawat Deeying, Western Digital Thailand Co.ltd Bang Pa-in Industrial Estate, Khlongjig, Bang Pa-in, Phra Nakhon Si Ayutthaya, Thailand. 

Manuscript received on August 01, 2020. | Revised Manuscript received on August 05, 2020. | Manuscript published on September 30, 2020. | PP: 388-394 | Volume-9 Issue-3, September 2020. | Retrieval Number: 100.1/ijrte.C4509099320 | DOI: 10.35940/ijrte.C4509.099320
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© The Authors. Blue Eyes Intelligence Engineering and Sciences Publication (BEIESP). This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/)

Abstract: The objective of this research is to study the effect of laser energy and Nitrogen flow on the solder joints of the Head Gimbal Assembly (HGA). The soldering of the HGA components isn’t the same as general semiconductors. Since the soldering figure perpendicular to each other so that, it was used the laser solder jet bonding system. The solder jet bonding system uses a solder ball consisting of Sn-2.0Ag-0.7Cu (SAC207) is used for connection of the HGA pad made from a Cu trace coated with Au. The growth of intermetallic compounds (IMCs) and shear strength will be analyzed to investigate the effects of laser energy and Nitrogen flow on solder joint reliability. In this research, laser energy levels since 2, 2.5, 3, 3.5, 4, and 4.5 mJ and keep the Nitrogen flow value at 90 mbar. As for the Nitrogen flow effect analysis, the Nitrogen flow level was used at 80, 100, 120, and 140 mbar and keep the laser energy value 3.5 mJ. The results of the study show that the increased levels of laser energy can inhibit the growth of intermetallic compounds as well as the AuSn4 phase that can present benefit to solder joints with results showing within the shear strength to increase significantly. The increase in Nitrogen flow levels has the same effect as the increase in laser energy levels, which can decreases the growth of intermetallic compounds and AuSn4 phase also including increased shear strength. The difference between laser energy and Nitrogen flow increasing shows the level of laser energy can clearly distinct the effect on each level. But the increase in Nitrogen flow level is statistically insignificant from each level. 
Keywords: Intermetallic compound, Laser solder jet bonding, SAC solder, solder joints.