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.
Tuesday, April 27, 2010
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.
Wednesday, April 14, 2010
1st week of Internship
I got an offer to do my Internship programme at ON Semiconductor Seremba.
My first day at this company was 5th of April. I reached the guard house at around 7.45am and went to the Human Resource office after getting my temporary pass for the day. I reported to Mr T. Kumar who was the person incharge at the HR office. He asked me to go into a room and read up some rules and regulations need to be followed during working hours. After readin the rules and regulations me and another trainee also from UNITEN was asked to fill up a few forms regarding our personal details. After doing so we were given forms to fill in our details to make our company pass. After making the company pass we were given our lockers to put our belongings. Mr T. Kumar after that called our respective supervisors to pick us up from the HR office. It was 10AM by that time and i was given a 15 minutes break time. After break i went back to my cubicle and than came my supervisor Mr. Shutesh. Mr. Shutesh gave me a brief explanation what my work was all about. He also gave me some information about the company and about semiconductors. Mr. Shutesh is a very friendly and knowledgeable guy. Mr Shutesh gave me a few semiconductor books to read to make me understand more on semiconductor even i am not taking electrical and electronics engineering course. He said is important for me to know more than knowing less. He told me my task will be more on Finite Element Analysis (FEA). I went back to my cubicle and met Mr Azhar over there. He was incharged in giving me task to be done during my industrial training. I just read about the semiconductor and try to understand about the materials used in semicondcutors. It was a quite tiring day at work as it was my first day working from 8.00 AM to 5.30 PM.
On the second day 6th April, I reached my office about 7.50AM. During the second day there was nothing much as i continue to read my semiconductor notes and also was given a few software manuals that will be used during my industrial training tasks.
7th April 2010, the third day. Today Mr Shutesh told me that he will take me on a knowledge tour to the company production line. I was given the smock to use. It is a must to use the smock when we are in the production line. Before lunch time, i was brought to the Front End Process side. Here i got to see how the begining of a semiconductor Process. I was shown and given explanation about the die bond process, die curing process, plasma cleaning process, and also the wire bond process. It is lunch time and i went to have lunch with my work mates. After lunch i was anxiously waitin for my supervisor to bring me to the back end process site. As i was told earlier by Mr. Shutesh, i will be looking at molding compund, plating, final test and dicing process in the back end process area. In the molding process, i saw how the type of mold compund used and also the conventional and modern process for molding took place. Obviously the modern process is faster than the conventional process. Next i was brought to the plating process area. In this area i didnt get to see much on how the process was done as it was a fully covered process from the begining until the ending because it uses a lot of chemicals during this process. Normally the process of plating uses Tin as its material. Plating is done mainly because the lead frame component will get oxide if it is left outside. After the plating is done the package will be brought to the dicing section where the units will be diced into its individual shape and sent to the final test area. In the final test area, the units are feeded into a machine where the machine is programmed to test the unit according to its usage. After the final test process, the unit goes to a process called tape and reel which is the final process in the back end area,and finally the units are ready to be package and shipped to its customers. I was also given a glance through the failure analysis lab where those failed and rejected units are tested and defined for its defects.
8th April 2010.
Mr Shutesh exposed me with another important element is semiconductor assembly industry. He taught me how to do measurements on the units which are produced. This measurement is done and the data is collected according to elements measured. The measurements are done using a scope where it displays the enlarged version of the unit on the LCD screen and the readings are shown. A variety of reading is taken randomly choosing random units. 30 measurements were taken and recorded. After recording, the data is transfered to the Microsoft Excel worksheet and later calculation of min value, max value,average value,standard deviation, and also Cpk calculation is done. The new thing that i learned from this measurements is the Cpk calculation which means the units production capability. From this production capability, we can know how many parts per million defects that we have.
9th April 2010.
It's the last day of the week. Mr Shutesh called me to his office and asked me what i have learned and understand so far. He also asked me weather there is anything i am not sure of. He told me, that the process tour was for me to know what are the material used and the important part is I must know about the properties of materials that is used in the production line. It is important for me to know about the materials properties, as it is important later on when I am doing the Finite Element Analysia (FEA). All those material properties will be the main input for the solution for calculation. Lets call it a day in rest during the weekend.!!~~!!
My first day at this company was 5th of April. I reached the guard house at around 7.45am and went to the Human Resource office after getting my temporary pass for the day. I reported to Mr T. Kumar who was the person incharge at the HR office. He asked me to go into a room and read up some rules and regulations need to be followed during working hours. After readin the rules and regulations me and another trainee also from UNITEN was asked to fill up a few forms regarding our personal details. After doing so we were given forms to fill in our details to make our company pass. After making the company pass we were given our lockers to put our belongings. Mr T. Kumar after that called our respective supervisors to pick us up from the HR office. It was 10AM by that time and i was given a 15 minutes break time. After break i went back to my cubicle and than came my supervisor Mr. Shutesh. Mr. Shutesh gave me a brief explanation what my work was all about. He also gave me some information about the company and about semiconductors. Mr. Shutesh is a very friendly and knowledgeable guy. Mr Shutesh gave me a few semiconductor books to read to make me understand more on semiconductor even i am not taking electrical and electronics engineering course. He said is important for me to know more than knowing less. He told me my task will be more on Finite Element Analysis (FEA). I went back to my cubicle and met Mr Azhar over there. He was incharged in giving me task to be done during my industrial training. I just read about the semiconductor and try to understand about the materials used in semicondcutors. It was a quite tiring day at work as it was my first day working from 8.00 AM to 5.30 PM.
On the second day 6th April, I reached my office about 7.50AM. During the second day there was nothing much as i continue to read my semiconductor notes and also was given a few software manuals that will be used during my industrial training tasks.
7th April 2010, the third day. Today Mr Shutesh told me that he will take me on a knowledge tour to the company production line. I was given the smock to use. It is a must to use the smock when we are in the production line. Before lunch time, i was brought to the Front End Process side. Here i got to see how the begining of a semiconductor Process. I was shown and given explanation about the die bond process, die curing process, plasma cleaning process, and also the wire bond process. It is lunch time and i went to have lunch with my work mates. After lunch i was anxiously waitin for my supervisor to bring me to the back end process site. As i was told earlier by Mr. Shutesh, i will be looking at molding compund, plating, final test and dicing process in the back end process area. In the molding process, i saw how the type of mold compund used and also the conventional and modern process for molding took place. Obviously the modern process is faster than the conventional process. Next i was brought to the plating process area. In this area i didnt get to see much on how the process was done as it was a fully covered process from the begining until the ending because it uses a lot of chemicals during this process. Normally the process of plating uses Tin as its material. Plating is done mainly because the lead frame component will get oxide if it is left outside. After the plating is done the package will be brought to the dicing section where the units will be diced into its individual shape and sent to the final test area. In the final test area, the units are feeded into a machine where the machine is programmed to test the unit according to its usage. After the final test process, the unit goes to a process called tape and reel which is the final process in the back end area,and finally the units are ready to be package and shipped to its customers. I was also given a glance through the failure analysis lab where those failed and rejected units are tested and defined for its defects.
8th April 2010.
Mr Shutesh exposed me with another important element is semiconductor assembly industry. He taught me how to do measurements on the units which are produced. This measurement is done and the data is collected according to elements measured. The measurements are done using a scope where it displays the enlarged version of the unit on the LCD screen and the readings are shown. A variety of reading is taken randomly choosing random units. 30 measurements were taken and recorded. After recording, the data is transfered to the Microsoft Excel worksheet and later calculation of min value, max value,average value,standard deviation, and also Cpk calculation is done. The new thing that i learned from this measurements is the Cpk calculation which means the units production capability. From this production capability, we can know how many parts per million defects that we have.
9th April 2010.
It's the last day of the week. Mr Shutesh called me to his office and asked me what i have learned and understand so far. He also asked me weather there is anything i am not sure of. He told me, that the process tour was for me to know what are the material used and the important part is I must know about the properties of materials that is used in the production line. It is important for me to know about the materials properties, as it is important later on when I am doing the Finite Element Analysia (FEA). All those material properties will be the main input for the solution for calculation. Lets call it a day in rest during the weekend.!!~~!!
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