2Ambitious
Newbie level 4
I'm a student working on a very basic, low-performance imaging hardware project. It is for my own interest, it is not homework (thank goodness they don't assign these things for homework!)
The project is very simple, I just need to interface a OVM7690 CMOS camera to a micro controller. I want to solder the CMOS camera to a flex-circuit (those brown polyimide ones) breakout board / ribbon cable and then solder the flex circuit to a PCB. I have some basic questions that I haven't been able to find the answer to, even after a considerable effort. I would be very grateful if someone who knows this stuff could give me a few tips and pointers.
1. I know there are several flex circuit prototyping companies advertising on the internet (All Flex Inc. Power Design Services), but can I realistically expect quotes similar to PCB costs or are they going to want thousands of dollars? Should I even bother asking them :???:
2. I think I've seen flex circuits soldered onto PCB directly without any interface. Is that correct? How might these solder pads be represented in EDA software? Also, can BGA (actually CSP - chip scale package) be soldered to a flex circuit or will it break off? What if I use epoxy to reinforce the connection?
3. Some people talk about impedance matching high frequency circuit PCBs / traces. I also know that impedance matching is only needed where the logic transition time is in the range of the round-trip time of a trace (https://www.edaboard.com/threads/142919/). Realistically, do I really need to worry about this? Can I just treat it like a normal DC circuit? The clock speed of this cam is 6 ~ 27 MHz, but for a QVGA 30 fps image I need the lower end of the range. The path from camera to micro controller is probably in the centimeter range.
(P.S. if anyone is interested I'm hoping to build the [to best of my knowledge] smallest first-person-view RC airplane!)
The project is very simple, I just need to interface a OVM7690 CMOS camera to a micro controller. I want to solder the CMOS camera to a flex-circuit (those brown polyimide ones) breakout board / ribbon cable and then solder the flex circuit to a PCB. I have some basic questions that I haven't been able to find the answer to, even after a considerable effort. I would be very grateful if someone who knows this stuff could give me a few tips and pointers.
1. I know there are several flex circuit prototyping companies advertising on the internet (All Flex Inc. Power Design Services), but can I realistically expect quotes similar to PCB costs or are they going to want thousands of dollars? Should I even bother asking them :???:
2. I think I've seen flex circuits soldered onto PCB directly without any interface. Is that correct? How might these solder pads be represented in EDA software? Also, can BGA (actually CSP - chip scale package) be soldered to a flex circuit or will it break off? What if I use epoxy to reinforce the connection?
3. Some people talk about impedance matching high frequency circuit PCBs / traces. I also know that impedance matching is only needed where the logic transition time is in the range of the round-trip time of a trace (https://www.edaboard.com/threads/142919/). Realistically, do I really need to worry about this? Can I just treat it like a normal DC circuit? The clock speed of this cam is 6 ~ 27 MHz, but for a QVGA 30 fps image I need the lower end of the range. The path from camera to micro controller is probably in the centimeter range.
(P.S. if anyone is interested I'm hoping to build the [to best of my knowledge] smallest first-person-view RC airplane!)
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