hi, i really need your help
im new with this area of electronic.. i have really basic knowledge..
i got some progect for some company and i ran into the arduino development board,
i think it can be very helpfull. but to be sure i need your help to tell me if its possible.
i have some cirtuit with 2 dies.
and i have to check the capacitance of the dies
it have 7 wires (one of them is ground)
so the measurment is one wire with the ground every time.
i have socket fort the ciruit and the output is the 7 wires.
i want to measure all the 6 wires and transfer the data to my pc.
then export it to some log file or exel that will arange the data for every cirtuit i check, and add a serial number for every ciruit.
(it ment to check about 400 cirtuits a week)
i'll be very grateful if someone could help me building the project or just advice me what to do..
There are a few ways to measure capacitance and I don't see any great difficulty with that side of it. But I assume that you would need to associate each set of measurements with the physical component that the measurements were for. How do you plan to do that?
by serial numbers..
if the program will export me a s/n for any set of measurment, i can write the s/n on any cirtuit.. its no problem.
i'll be very glad if you can help me with that.
maybe if you can tell me what to buy , and some plan how to do it.
even a clue how to do it will very helpfull,
sinus89:
by serial numbers..
if the program will export me a s/n for any set of measurment, i can write the s/n on any cirtuit.. its no problem.
i'll be very glad if you can help me with that.
maybe if you can tell me what to buy , and some plan how to do it.
even a clue how to do it will very helpfull,
tnx in advanced,
nir.
we have in our factory another check station for other project.
and for any test it does, the program exporting a text file with the s/n and the measurment results in it.
it doesnt have to be in exel.
It sounds as if you have got several separate problems
Implement a sketch + hardware to produce a set of capacitance values at the Arduino.
Come up with a workable reliable way to connect each device to your hardware and trigger a measurement.
Transfer the set of results to the PC (I suggest simply printing them to serial port
At the PC, save the results in some permanent form (you could simply append to CSV format text file). If you want to assign a serial number to the device, this would be the time to do it. You could print a label at the same time if you wanted.
For me, the mechanism to measure the capacitance is the biggest unknown, only because I haven't done this type of sensing before. You may be able to get a digital capacitance sensor which you can just wire up. I suspect there is a much simpler DIY solution based on either charge sharing (charge a known capacitor to a known voltage, connect to your subject capacitor and measure the voltage; the capacitance can be calculated from that) or by connecting a constant current source and measuring the rate of voltage change. Which works best might depend on the size of capacitor you're trying to measure, the accuracy you need to achieve, leakage current and so on. If it was me, I'd try out the various techniques manually and see whether I can get accurate repeatable measurements. There are probably other technique you could use such as resonating the capacitor with a coil and seeing what the resonant frequency is. Probably, there's a well known and obvious technique for determining capacitance and hopefully Google will tell you what it is.
It depends greatly on what the range of capacitance you are trying to measure is.
Are we talking about pF or uF or what.
i have some cirtuit with 2 dies.
What is a dies?
so the measurment is one wire with the ground every time.
i have socket fort the ciruit and the output is the 7 wires.
Do you mean that each of the 7 wires has to be grounded in turn, when it is the capacitance on the other 6 wires are taken?
This would give you 30 measurements although some of them will be duplicates.
peter, the only digital meter i found was standalone circuit with 7 segment display as the output,
i dont know if i'll be abale to change the 7 sigment output to transfer the measurments to the arduino circuit.
i'll would rather not to deal with DIY,so if you know where to buy a digital meter i can wire up to the ardunio cirtuit , or how to wire up the
capacitance meter i found, i'll prefer it.
here is the link http://www.seeedstudio.com/depot/capacitance-meter-kit-p-268.html
i really have no clue about the ardunio's program and what i need to buy..
mm.. mike , im talking about... between 0.40 uF to 0.60 uF,
die is other name for chip. i packaging COB (chip on board) on a ciruit, with automatic wire bonder, if you know it.
and i have to check if the chip is working by this measurment, before i close it with globtop glue.
i have 7 wires.
one of them is ground,
and im checking the same ground wire with the other 6 wires, one at a time.
it become 6 measurment results.
I've never used any sensors to measure capacitance, but they seem to be available and not particularly expensive:
If you can get hold of half a dozen CDCs with an output suitable for the Arduino to access, I think that would probably be quicker, easier and more reliable than any home-made measurement technique.
There are basically two ways to measure a capacitance.
Feed it with AC and measure it's capacitive reactance, just like a resistor.
Charge it up and see how long it takes to discharge it.
Normally 1) works better with low capacitance and 2) works better with big ones.
0.40 uF to 0.60 uF,
Is a lot to get from a chip mounting die if it is due to stray C only I would have expected in the pF region. However, if there are components you are trying to measure that will explain it. This range is such that either method would be suitable.
thanks for the quick response and for the help guys.
i didn't see the Capacitance Meter project on the site.. (strange.. i was looking over there )
but i guess its covers all i need!
it have the schematic i need! and the program!
i guess i'll just need some help with editing the program aliitle bit , cause i saw the exemple is for 1 capacitor to check, and i actually have 6.
i need the program to know do the measurment automatic without me have to change wires,is it possible? maybe to connect any one from the wires to other input
and the program wiil know to take one of them at a time?
btw, there is no chance it will destroy the chip's?
untill now we did the measurment with fluke, i dont know how he checks it, i guess he supply voltage to the chips too,
but i dont know how much its supplies, and how much the arduino wiil supply? and if the ardunio voltage wiil be too big, i can connect a potentiometer to the input, no?
can you tell me what i need to buy for building the exemple in the site? because i saw there is a several kits of arduino ciruit,and its really look great
)