Advanced search options

Advanced Search Options 🞨

Browse by author name (“Author name starts with…”).

Find ETDs with:

in
/  
in
/  
in
/  
in

Written in Published in Earliest date Latest date

Sorted by

Results per page:

Sorted by: relevance · author · university · dateNew search

You searched for subject:(laser dicing). Showing records 1 – 3 of 3 total matches.

Search Limiters

Last 2 Years | English Only

No search limiters apply to these results.

▼ Search Limiters


NSYSU

1. Hsu, Ching-Hu. Study of laser cutting of Sapphire.

Degree: Master, Mechanical and Electro-Mechanical Engineering, 2016, NSYSU

In this thesis, we study laser machining of sapphire and related issues. In order to achieve the industryâs general standard so this study focuses on sapphire processing optimum process parameters. There are two main processing needed, laser scribing for splitting and laser dicing. Laser scribing for splitting needs a cut depth of 1/3 the thickness of sapphire, and the finished surface canât have chipping (< 30 μm), random crack or closet breaking. In addition, the processing time must be fast and stable. Therefore, this thesis proposes three different experimental dicing and processing parameters. First, experiment applies simple optical system (direct beam) with âoptical trepanâ and XY-stage with laser source of ultraviolet. The parameters of laser frequency at 25 kHz, laser power of 3 watt and once round rip cutting with speed 5 mm/s can achieve depth of 1/3 the thickness. Using optical improvements, installation âoptical trepanâ in optical path to make small circle around area circle can improve the speed of XY-stage. Then laser dicing can be achieved (the gap between the surface and back side is about 40 μm). Second experiment is using ultraviolet laser source. But in the optical system, we install âLaser Scannerâ (Galvo Head) with high cutting speed characteristic and high freedom of laser machining. Laser frequency of 25 kHz, laser power of 3 watt and 15 times round rip cutting with speed 100 mm/s can achieve depth of 1/3 the thickness. In high speed and high freedom of laser machining processing, âRepetition rate of machiningâ is more important. And the best repetition rate in scanner is 80%. Finally, to completely cut sapphire, we use a high power infrared fiber laser (150 watt) as a processing source. Installation laser cutter and coaxial blowing with different type cooling gas can improve the IR laser caused thermal effects. The best cooling gas is nitrogen (9 kgf/cm2), which can isolate sapphire and oxygen interacting. Thus the thermal affected region can be less than 20 μm. Advisors/Committee Members: C. L. Chiu (chair), Cheng-Tang Pan (committee member), Wang, Yu-Jen (chair).

Subjects/Keywords: laser cutter; trepan; laser scanner; fiber laser; laser maching; laser scribing; laser dicing; sapphire; infrared laser; ultraviolet laser

Record DetailsSimilar RecordsGoogle PlusoneFacebookTwitterCiteULikeMendeleyreddit

APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6th Edition):

Hsu, C. (2016). Study of laser cutting of Sapphire. (Thesis). NSYSU. Retrieved from http://etd.lib.nsysu.edu.tw/ETD-db/ETD-search/view_etd?URN=etd-0028116-211556

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Chicago Manual of Style (16th Edition):

Hsu, Ching-Hu. “Study of laser cutting of Sapphire.” 2016. Thesis, NSYSU. Accessed December 14, 2019. http://etd.lib.nsysu.edu.tw/ETD-db/ETD-search/view_etd?URN=etd-0028116-211556.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

MLA Handbook (7th Edition):

Hsu, Ching-Hu. “Study of laser cutting of Sapphire.” 2016. Web. 14 Dec 2019.

Vancouver:

Hsu C. Study of laser cutting of Sapphire. [Internet] [Thesis]. NSYSU; 2016. [cited 2019 Dec 14]. Available from: http://etd.lib.nsysu.edu.tw/ETD-db/ETD-search/view_etd?URN=etd-0028116-211556.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Council of Science Editors:

Hsu C. Study of laser cutting of Sapphire. [Thesis]. NSYSU; 2016. Available from: http://etd.lib.nsysu.edu.tw/ETD-db/ETD-search/view_etd?URN=etd-0028116-211556

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation


NSYSU

2. Ou , Chun-Hsien. FE Analysis for PBGA and Optimization of Laser Dicing for QFN Package.

Degree: Master, Mechanical and Electro-Mechanical Engineering, 2016, NSYSU

In this study, the optimal parameters focuses on decreasing the stress difference between two materials and increasing productivity and yield. The size of Quad Flat No leads (QFN) packaging are getting smaller, and laser dicing also gradually replaces the diamond cutting to avoid delamination. Therefore, Taguchi method and Analysis of variance (ANOVA) are used to determine the optimal parameters in the laser dicing, and surface of dicing path is analyzed by Energy-dispersive X-ray spectroscopy (EDS). Different material plating are diced by different laser wavelength and the dicing results are compared in the this study. There are many re-depositions in the dicing path after laser dicing because the carbon compound reacts with other element. The carbon content in Ultraviolet (UV) laser dicing packaging is smaller than Infrared (IR) laser. The IR laser has the same dicing situation between different materials, but the UV laser would decrease dicing effectiveness when dicing harder materials. The different shrinkages rate of two materials lead to discontinuous stress in high temperature and high molding pressure Ball Grid Array (BGA) process, therefore this study carries out finite element analysis to improve the processing. From Taguchi experiment method and ANOVA, the optimal parameters of IR laser are 90 mm/s for speed, 90 times for pass, 80 kHz for frequency, and 60 % for power, and the most significant contribution of factor is speed with 36%. The optimal parameters of UV laser are 90 mm/s for speed, 90 times for pass, 65 kHz for frequency, and 70% for power, and the most significant contribution of factor is speed with 38%. From simulated results, the optimal parameters of uniform design are 31.7 MPa for molding pressure, 171.61°C for temperature, and 358.33 μm for shoulder width. The best parameters of response surface method are 42.57 MPa for molding pressure, 185°C for temperature, and 800 μm for shoulder width. The two experimental methods have different trends. According to real products, the interaction exists in factor of processing, so the response surface method is more accurate than the uniform design. Advisors/Committee Members: Cheng-Tang Pan (committee member), Zong-Hsin Liu (chair), Y. J. Chen (chair), Yeong-Maw Hwang (chair), Chi-Hui Chien (chair).

Subjects/Keywords: Response surface method; Finite element analysis; Taguchi method; Laser dicing

Record DetailsSimilar RecordsGoogle PlusoneFacebookTwitterCiteULikeMendeleyreddit

APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6th Edition):

Ou , C. (2016). FE Analysis for PBGA and Optimization of Laser Dicing for QFN Package. (Thesis). NSYSU. Retrieved from http://etd.lib.nsysu.edu.tw/ETD-db/ETD-search/view_etd?URN=etd-1030115-222727

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Chicago Manual of Style (16th Edition):

Ou , Chun-Hsien. “FE Analysis for PBGA and Optimization of Laser Dicing for QFN Package.” 2016. Thesis, NSYSU. Accessed December 14, 2019. http://etd.lib.nsysu.edu.tw/ETD-db/ETD-search/view_etd?URN=etd-1030115-222727.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

MLA Handbook (7th Edition):

Ou , Chun-Hsien. “FE Analysis for PBGA and Optimization of Laser Dicing for QFN Package.” 2016. Web. 14 Dec 2019.

Vancouver:

Ou C. FE Analysis for PBGA and Optimization of Laser Dicing for QFN Package. [Internet] [Thesis]. NSYSU; 2016. [cited 2019 Dec 14]. Available from: http://etd.lib.nsysu.edu.tw/ETD-db/ETD-search/view_etd?URN=etd-1030115-222727.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Council of Science Editors:

Ou C. FE Analysis for PBGA and Optimization of Laser Dicing for QFN Package. [Thesis]. NSYSU; 2016. Available from: http://etd.lib.nsysu.edu.tw/ETD-db/ETD-search/view_etd?URN=etd-1030115-222727

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation


NSYSU

3. Chiu, Chen-chih. Optimization of Laser Dicing for QFN Packages.

Degree: Master, Mechanical and Electro-Mechanical Engineering, 2015, NSYSU

In this study, Taguchiâs experiment method and analysis of variance method (ANOVA) were used to optimize dicing parameter and the degree of affecting of each factor for 1064 nm and 355 nm lasers to dice QFN package. The optimal parameters of 1064 nm laser dicing were obtained as 30 mm/s for dicing speed, 60 passes for dicing pass, 65 kHz for laser frequency, and 70% max. power. The result of ANOVA shows that the factors to affecting the dicing quality in sequence are pass (66%), speed (18%), frequency (10%), and power (6%). The optimal parameters of 355 nm laser dicing were obtained as 60 mm/s for dicing speed, 30 passes for dicing pass, 65 kHz for laser frequency, and 60 % max. power. The factors to affecting the dicing quality by ANOVA in sequence are pass (39%), frequency (38%), power (23%), and speed (0.43%). To compare with 1064 nm and 355 nm laser dicing, the result of OM and EDS shows that the 355 nm laser dicing has no HAZ phenomenon after dicing. The amount of dicing through the 0.2 mm Cu and 0.65 mm compound was about 180 passes and 255 passes, respectively, by using 355 nm optimal parameters. ANSYS software was used to simulate the distribution of temperature and thermal stress. The different layer in the package was analyzed by adjusting the pass which is the main factor from results of experiment. The result shows that the Cu/Compound, Ag/Compound, and Cu/Ag/Compound layers have similar temperature in the same pass. In terms of thermal stress, the amount of G631H is two to five times greater than 9240HF in Cu/Compound layer, but the amount of 9240HF is lightly greater than G631H in Ag/Compound and Cu/Ag/Compound layers. Advisors/Committee Members: Tsung-Tien Wu (chair), Yong-Jheng Chen (chair), Zong-Hsin Liu (chair), Cheng-Tang Pan (committee member), Chi-Hui Chien (chair).

Subjects/Keywords: Finite Element Method; Analysis of Variance Method; Laser dicing; QFN package; ANSYS; Taguchi's Experiment Method

Record DetailsSimilar RecordsGoogle PlusoneFacebookTwitterCiteULikeMendeleyreddit

APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6th Edition):

Chiu, C. (2015). Optimization of Laser Dicing for QFN Packages. (Thesis). NSYSU. Retrieved from http://etd.lib.nsysu.edu.tw/ETD-db/ETD-search/view_etd?URN=etd-0530115-172058

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Chicago Manual of Style (16th Edition):

Chiu, Chen-chih. “Optimization of Laser Dicing for QFN Packages.” 2015. Thesis, NSYSU. Accessed December 14, 2019. http://etd.lib.nsysu.edu.tw/ETD-db/ETD-search/view_etd?URN=etd-0530115-172058.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

MLA Handbook (7th Edition):

Chiu, Chen-chih. “Optimization of Laser Dicing for QFN Packages.” 2015. Web. 14 Dec 2019.

Vancouver:

Chiu C. Optimization of Laser Dicing for QFN Packages. [Internet] [Thesis]. NSYSU; 2015. [cited 2019 Dec 14]. Available from: http://etd.lib.nsysu.edu.tw/ETD-db/ETD-search/view_etd?URN=etd-0530115-172058.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Council of Science Editors:

Chiu C. Optimization of Laser Dicing for QFN Packages. [Thesis]. NSYSU; 2015. Available from: http://etd.lib.nsysu.edu.tw/ETD-db/ETD-search/view_etd?URN=etd-0530115-172058

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

.