Its the 8th week and another month left for my internship. Gained alot of knowledge for this past few weeks and waiting to absorb more knowledge.
In this week i have spent most of my time in the production line getting to know how the wire bond process is done. There were a few machine specialist who were willing to tell me about the wire bonding process. Looking at them doing thier daily task was bored until learning some hands on with the machine took place. Learned some important parts of the machine and learned how to insert wire into the machine. Each device which is produced uses different methods of wire bonding. In this week i also learned the different ways of handling gold and copper wires.
On the last day of this week, the wire bond engineer Siew Han showed me how to setup the machine and gave me some guideline on how the machine operates. She set each parameter for the device which need to be runned on the following week by me. She was going on vacation leave and asked me to help her in running the EBR's for the device. She has set every important parameter and assigned an enginner to assist if any error happens during the execution.
Tuesday, June 8, 2010
Wednesday, June 2, 2010
Internship Week 7
In the 7th week of my internship, i started doing something new and different rom the previous weeks. The previous week i was more to the designing and analysis section, and this week is time for me to learn something about process.
I have visited the production line in the first week of my internship in this company. At that time it was just a brief explanation about the company. In this week i was placed in the molding or encapsulating section for the semiconductor package. Everything looks easy in this molding process as its done by the machine automatically but the tough part is all the input parameters need to be given by the process engineer incharged in this molding section.
Every parameter which is inserted into the machine needs to be varified for the safety during the molding process. To ensure nothing happens to the unit during molding a dummy molding session is done and analyzed.
In the molding department, the process engineer incharge Mr. Seah showed me how the complete molding process and inspection takes place. Mr Seah taught me how to clean the mold press chamber. A few steps were done to do the clean up.
The mold chamber cleaning process consists of a few steps. The mold press chamber is cleaned once in every 24 hours. This cleaning process is done to ensure there is no dirt in the molding chamber as the mold compound tends to stick at the chamber after a long time.
After showing me the details of the cleaning process Mr. Seah showed me how the molding is done and how the inspection is done.
The inspection is done on Xray to see weather there are any wire strips, mold void or incomplete fill during the molding process. The 3 problems above might cause the unit to be failed and rejected.
I have visited the production line in the first week of my internship in this company. At that time it was just a brief explanation about the company. In this week i was placed in the molding or encapsulating section for the semiconductor package. Everything looks easy in this molding process as its done by the machine automatically but the tough part is all the input parameters need to be given by the process engineer incharged in this molding section.
Every parameter which is inserted into the machine needs to be varified for the safety during the molding process. To ensure nothing happens to the unit during molding a dummy molding session is done and analyzed.
In the molding department, the process engineer incharge Mr. Seah showed me how the complete molding process and inspection takes place. Mr Seah taught me how to clean the mold press chamber. A few steps were done to do the clean up.
The mold chamber cleaning process consists of a few steps. The mold press chamber is cleaned once in every 24 hours. This cleaning process is done to ensure there is no dirt in the molding chamber as the mold compound tends to stick at the chamber after a long time.
After showing me the details of the cleaning process Mr. Seah showed me how the molding is done and how the inspection is done.
The inspection is done on Xray to see weather there are any wire strips, mold void or incomplete fill during the molding process. The 3 problems above might cause the unit to be failed and rejected.
WEEK 6 Internship
It has been 1 and a half months of internship. Everything looks fine at the moment and gaining more and more knowledge in the coming days.
For this week i was given a task to do the thermal analysis for the previous package which is QFN2545. The pure thermal analysis took me quite a time as i didnt know what was the commands all about. Thermal analysis is much more tougher than thermal stress analysis. Searching in the help menu of the software on what is the commands all about took me some time.
Unlike stress analysis which needs a lot of material properties, pure thermal analysis only needs the thermal conductivity of the materials,k.
The model for this package was taken from the previous assignment and only the analysis is different.
First of all we need to find the film coefficent for the unit. The commands for the calculation is done by the software. All need to be done is inserting certain numbers and formulas. After inserting the film coefficient, we need to input the heat flux for the material at its places and finally the boundry condition is input. The boundry condition is the package is set to an ambient temprature of 25 degree celcius.
After inputing all the properties and parameters, the solution for the package is done and the results is taken. The first simulation was a failure as the value that was displayed is more than what was needed. After finding out the problem and doing some changes in the commands the results is obtained again.
The process looks simple but it took me quite a time as it was a new thing for me to learn about.
For this week i was given a task to do the thermal analysis for the previous package which is QFN2545. The pure thermal analysis took me quite a time as i didnt know what was the commands all about. Thermal analysis is much more tougher than thermal stress analysis. Searching in the help menu of the software on what is the commands all about took me some time.
Unlike stress analysis which needs a lot of material properties, pure thermal analysis only needs the thermal conductivity of the materials,k.
The model for this package was taken from the previous assignment and only the analysis is different.
First of all we need to find the film coefficent for the unit. The commands for the calculation is done by the software. All need to be done is inserting certain numbers and formulas. After inserting the film coefficient, we need to input the heat flux for the material at its places and finally the boundry condition is input. The boundry condition is the package is set to an ambient temprature of 25 degree celcius.
After inputing all the properties and parameters, the solution for the package is done and the results is taken. The first simulation was a failure as the value that was displayed is more than what was needed. After finding out the problem and doing some changes in the commands the results is obtained again.
The process looks simple but it took me quite a time as it was a new thing for me to learn about.
Wednesday, May 12, 2010
5th Week of Training (3/5/10 - 7/5/10)
Time passed so fast during the weekend and its time to start the fifth week of my training. I was given several task to be done through out the week. This week Mr. Azhar asked me to used different Lead Frame Materials, different Die attach material and Different Molding compound material to do the analysis for the first package. This task was given to me to show how the die unit reacts to the different type of material used in production.
Lead Frame Material
1) C194
2) Alloy42
3) TAMAC 4
Die Attach Material
1)Epoxy Ablestik Sumitomo 1084P
2)Epoxy Sumitomo CRM 1076WB
Molding Compound Material
1)Sumitomo EME-G760
2)Sumitomo EME-G600
3)Nitto MP-8000CH4ES
Lead Frame Material
1) C194
2) Alloy42
3) TAMAC 4
Die Attach Material
1)Epoxy Ablestik Sumitomo 1084P
2)Epoxy Sumitomo CRM 1076WB
Molding Compound Material
1)Sumitomo EME-G760
2)Sumitomo EME-G600
3)Nitto MP-8000CH4ES
4th Week of Internship
2926th April 2010
Its the fourth week of my industrial training and i have learned many things and even looking forward to learn more in the time to come. Today, I was given a new package to analyze by myself without the help of Mr. Azhar. This task looks challenging. The drawing for this package looked more difficult. I begin to simplify the drawing in AutoCAD to prepare it for my analysis in ANSYS. After doing the simplification for the drawing the data was inserted into the ANSYS software and the simulation was started.
27th April 2010 - 28th April 2010
In both this days i did various analysis for this package same as the previous package to find out the suitable size and thickness
29th April 2010 - 30th April
Today i was given a more mechanical task. It has nothing to be done with semiconductor device. The problem was to analyze the corner angle bracket. The drawing was done manually is ANSYS using the menu commands. The process was one step by step and will be more detailed in the report with the drawings.
Tomorrow is 1st May and its LABOUR DAY. Finally i have the chance to celebrate Labour Day.
Its the fourth week of my industrial training and i have learned many things and even looking forward to learn more in the time to come. Today, I was given a new package to analyze by myself without the help of Mr. Azhar. This task looks challenging. The drawing for this package looked more difficult. I begin to simplify the drawing in AutoCAD to prepare it for my analysis in ANSYS. After doing the simplification for the drawing the data was inserted into the ANSYS software and the simulation was started.
27th April 2010 - 28th April 2010
In both this days i did various analysis for this package same as the previous package to find out the suitable size and thickness
29th April 2010 - 30th April
Today i was given a more mechanical task. It has nothing to be done with semiconductor device. The problem was to analyze the corner angle bracket. The drawing was done manually is ANSYS using the menu commands. The process was one step by step and will be more detailed in the report with the drawings.
Tomorrow is 1st May and its LABOUR DAY. Finally i have the chance to celebrate Labour Day.
Tuesday, April 27, 2010
3rd Week of internship
19th APRIL 2010
A beautiful Monday morning and i am ready for my third week of internship. Mr Azhar ask me to settle all my reports for the previous weeks tasks, and look for him once i am done. When i completed my reports, i looked for Mr Azhar and he gave me 4 new tasks to be done. Basically those tasks were to do some experiment on the previous package which I analyzed.
Task 1: Study the Lead Frame Thickness effect on principle stress S1
Task 2: Study the effect of Die Thickness on principle stress S1
Task 3: Study the effect of Die Attach Thickness on the principle stress S1
Task 4: Study the effect of Package Thickness on the principle stress S1
I begin to redo the drawings and also plot it into the ANSYS software. The stress analysis is onli done on the die unit as the other compnents such as lead frame, die attach and mold compund seldom have defects.
Even the task looks easy it takes a quite long time for the simulation to be done. The package modeling is done and the simulation is runned.
20th APRIL 2010
The simulation run for the initial size and is recorded and the data for the second simulation is created. First i choose to run the package thickness data. The package thickness dimensions is changed and the data is inserted into ANSYS. The simulation is first run for the 0.75mm package thickness and the results is obtained. After that i compared it with the 0.9mm package thickness. From this results, we get to compare how package thickness manipulation gives changes to the stress that is produced on the die.
21st APRIL 2010
The simulation for the die attach thickness is done according to the steps like previously done. The die thickness which was taken into comparisson are the 0.5mils/0.000013m and 1.0mils/0.0000254m. The results obtained was recorded and a graph is plotted for the analysis to be done.
22nd APRIL 2010
Today i was called to attend the company orientation program for new workers and trainees. Me and a few other trainess attended this program from 8.30am till 3.30pm. In this program, we were shown and briefed about the companies misson,vision, and other services provided by the company. After coming back from the orientation program, i continued with my simulation for the next set o data. This time it was time to analyze the effect of the lead frame thickness. The lead frame thickness which were analyzed is 8 Mils/0.000203m , 6 Mils/0.000152m , 4 Mils/0.000102m. The results were taken and saved.
23rd APRIL 2010
Its friday again and i am quite happy as it was the last day of work for the week. Today i came in to office and started to run my simulation for the last criteria which is the die thickness. 4 die thickness were to be tested and it would take a long time as one simulation will take around 2 hours. The die thickness that was tested is 10 Mils/0.000254m , 8 Mils/0.000203m , 6 Mils,0.000152m and 4 Mils/0.000102m. After running the simulation for all 4 die thickness, the data is taken down and it was time to start doin my report for the 4 different tests. Its 5.30pm and time to go back and have a weekend rest and continue my reports on Monday.
A beautiful Monday morning and i am ready for my third week of internship. Mr Azhar ask me to settle all my reports for the previous weeks tasks, and look for him once i am done. When i completed my reports, i looked for Mr Azhar and he gave me 4 new tasks to be done. Basically those tasks were to do some experiment on the previous package which I analyzed.
Task 1: Study the Lead Frame Thickness effect on principle stress S1
Task 2: Study the effect of Die Thickness on principle stress S1
Task 3: Study the effect of Die Attach Thickness on the principle stress S1
Task 4: Study the effect of Package Thickness on the principle stress S1
I begin to redo the drawings and also plot it into the ANSYS software. The stress analysis is onli done on the die unit as the other compnents such as lead frame, die attach and mold compund seldom have defects.
Even the task looks easy it takes a quite long time for the simulation to be done. The package modeling is done and the simulation is runned.
20th APRIL 2010
The simulation run for the initial size and is recorded and the data for the second simulation is created. First i choose to run the package thickness data. The package thickness dimensions is changed and the data is inserted into ANSYS. The simulation is first run for the 0.75mm package thickness and the results is obtained. After that i compared it with the 0.9mm package thickness. From this results, we get to compare how package thickness manipulation gives changes to the stress that is produced on the die.
21st APRIL 2010
The simulation for the die attach thickness is done according to the steps like previously done. The die thickness which was taken into comparisson are the 0.5mils/0.000013m and 1.0mils/0.0000254m. The results obtained was recorded and a graph is plotted for the analysis to be done.
22nd APRIL 2010
Today i was called to attend the company orientation program for new workers and trainees. Me and a few other trainess attended this program from 8.30am till 3.30pm. In this program, we were shown and briefed about the companies misson,vision, and other services provided by the company. After coming back from the orientation program, i continued with my simulation for the next set o data. This time it was time to analyze the effect of the lead frame thickness. The lead frame thickness which were analyzed is 8 Mils/0.000203m , 6 Mils/0.000152m , 4 Mils/0.000102m. The results were taken and saved.
23rd APRIL 2010
Its friday again and i am quite happy as it was the last day of work for the week. Today i came in to office and started to run my simulation for the last criteria which is the die thickness. 4 die thickness were to be tested and it would take a long time as one simulation will take around 2 hours. The die thickness that was tested is 10 Mils/0.000254m , 8 Mils/0.000203m , 6 Mils,0.000152m and 4 Mils/0.000102m. After running the simulation for all 4 die thickness, the data is taken down and it was time to start doin my report for the 4 different tests. Its 5.30pm and time to go back and have a weekend rest and continue my reports on Monday.
Friday, April 16, 2010
2nd week of Intership
12th April 2010
Weekends ended and its time to continue work for the second week of my internship. I arrived early around 7.45am and had breakfast at the cafe. Got back to my cubicle and around 8.30am came Mr. Azhar. He gave me details on how to use the AutoCAD software ANSYS software to do the finite element analysis for a semiconductor package. He used drawings to explain to me to make sure i am clear about what is he saying about. He told me its important to know the stress level in a semiconductor package because its for us to know weather it can be produced for customers or not.
It took me quite long to complete the partition of the AutoCAD drawing. Mr Azhar is a very patient engineer and good at explaining. I will always approach him on the things which i am not sure of. After completing the drawing i went for my lunch as it was already 12.30pm. I arrived back to my office around 1.20pm and waited for Mr Azhar to proceed to the next step of the drawings.
Mr Azhar came and told me to find the coordinates of the end points of the drawing and copy it into a text file. While i was doing that, the time passed quick and it was already 5.30pm when i finished copying the coordinates into the text file.
13th April 2010
I am ready to use the simulation software to run the thermal stress analysis simulation. the coordinates that i pasted in the text file was made the input file for my modelling in ANSYS. ANSYS is a software used to run simulation for stresses. ANSYS is a very interesting software. It is challenging when the drawing is done because the software doesnt allow any UNDO for error's. The modelling is done step by step. Materials and colours are assigned to the layer. The most important part is we need to assign the type of material and material properties. If we input the wrong property for the material, the results that we get wont be accurate. After inserting all the parameters than the model is ready to be mashed for easier analysis to be done. ANSYS can me done using commands or manually using the menubar. The whole day was used doing the modelling as i was still new to this software. Mr Azhar told me once I get hands on it, it will be very easy to be done. The software is let to run when I was about to go home.
14th April 2010.
Its a new day. The results for my simulation is done. All together is got 7 diferent results according to the different load steps. From this simulation, the maximum stress a semiconductor package can stand is 210MPa. This is according to the Mohr's circle theory. The results that i got from the simulation is lower than 210MPa. This tells me that the package can be manufactured.
Weekends ended and its time to continue work for the second week of my internship. I arrived early around 7.45am and had breakfast at the cafe. Got back to my cubicle and around 8.30am came Mr. Azhar. He gave me details on how to use the AutoCAD software ANSYS software to do the finite element analysis for a semiconductor package. He used drawings to explain to me to make sure i am clear about what is he saying about. He told me its important to know the stress level in a semiconductor package because its for us to know weather it can be produced for customers or not.
It took me quite long to complete the partition of the AutoCAD drawing. Mr Azhar is a very patient engineer and good at explaining. I will always approach him on the things which i am not sure of. After completing the drawing i went for my lunch as it was already 12.30pm. I arrived back to my office around 1.20pm and waited for Mr Azhar to proceed to the next step of the drawings.
Mr Azhar came and told me to find the coordinates of the end points of the drawing and copy it into a text file. While i was doing that, the time passed quick and it was already 5.30pm when i finished copying the coordinates into the text file.
13th April 2010
I am ready to use the simulation software to run the thermal stress analysis simulation. the coordinates that i pasted in the text file was made the input file for my modelling in ANSYS. ANSYS is a software used to run simulation for stresses. ANSYS is a very interesting software. It is challenging when the drawing is done because the software doesnt allow any UNDO for error's. The modelling is done step by step. Materials and colours are assigned to the layer. The most important part is we need to assign the type of material and material properties. If we input the wrong property for the material, the results that we get wont be accurate. After inserting all the parameters than the model is ready to be mashed for easier analysis to be done. ANSYS can me done using commands or manually using the menubar. The whole day was used doing the modelling as i was still new to this software. Mr Azhar told me once I get hands on it, it will be very easy to be done. The software is let to run when I was about to go home.
14th April 2010.
Its a new day. The results for my simulation is done. All together is got 7 diferent results according to the different load steps. From this simulation, the maximum stress a semiconductor package can stand is 210MPa. This is according to the Mohr's circle theory. The results that i got from the simulation is lower than 210MPa. This tells me that the package can be manufactured.
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