And....0805's don't seem so small anymore! ;D - Page 1
Forum section: electronics / general

author: Falcon69
author_rank: Super Contributor
timestamp: December 31, 2014, 09:36:50 am
content: So, today I worked 12 hours straight, No lunch either, one bathroom break.All this time dedicated to hand placing 100's of 0603 resistors and caps. Might be time to inviest in a pick and place machine.I had a few other items, like SOT-363 and TSSOP-14 packages.Anyway....After placing so many 0603 components, I can't believe how huge the 0805's felt. Maybe I'll start working with some 0402's next, then maybe these 0603's won't be so bad.Anyone else experience this, this feeling of a small component suddenly feeling like you're placing an 1812 or larger? That's kinda what it felt like going from the 0603's to the 0805's after placing so many 0603's.

author: Rerouter
author_rank: Super Contributor
timestamp: December 31, 2014, 09:59:24 am
content: Having had to repair the flex ribbon traces on a high density LCD, i can confidently say 0603 is huge to me,I've had some 1812 resistors on one of my PCB's due to power requirements and been stuck thinking "These take up so much space"Then again i am short sighted with steady hands...

author: Falcon69
author_rank: Super Contributor
timestamp: December 31, 2014, 10:04:23 am
content: The smallest component I have placed so far is a TVS Bi-Directional Diode. SOD-924. I'm not sure I can go smaller. I have trouble seeing that small.Ive seen some of those ribbon traces you are talking about when I've taken cell phones apart to replace the digitizer screens. Some of those resistors and caps are like a spec of dust. I envy you. I can't do that small, my hands are steady enough.

author: zapta
author_rank: Super Contributor
timestamp: December 31, 2014, 04:04:22 pm
content: Quote from: Falcon69 on December 31, 2014, 10:04:23 amGet a cheap stereo microscope from eBay. It will make a big difference.

author: KD0CAC John
author_rank: Frequent Contributor
timestamp: December 31, 2014, 04:49:01 pm
content: Much like any trade , skill or hobby .With a lot of practice , it can be amazing what can be done .I shooting sports , tell someone that hunts [ shoots 5 shots a yr , 3 to sight in and 1 or 2 for the hunt ] etc and they will argue endlessly something can't be done .Machining , after some time , you can notice a few thousandth's form across the room .What is amazing , is what we can do , if we try

author: lgbeno
author_rank: Frequent Contributor
timestamp: January 01, 2015, 05:02:41 pm
content: 0805's are huge, I usually use 0402 but typically use a microscope for placement.0603 is a nice size for the naked eye.Awhile back I did a build of about 500 placements of 0402 with naked eye and it was possible but a strain, could have been 2x faster with 0603.The issue that I have with 0402 is their mass is so small, sometimes they stick to the tweezers or little disturbances can move them from where I placed, more annoying than the vision aspect.Practice makes perfect though, I've reworked 0201 stuff with and without microscope as well. Same for .5mm qfns and dfns.Something that I found really hard to manage is sc-74 and sc-88 transistors, they are so prone to solder bridging

author: zapta
author_rank: Super Contributor
timestamp: January 01, 2015, 05:12:14 pm
content: Quote from: lgbeno on January 01, 2015, 05:02:41 pmA visor like this one also helphttp://www.doneganoptical.com/products/optivisorQuote from: lgbeno on January 01, 2015, 05:02:41 pmYou want a vacuum picker that doesn't require finger action to release (shacking). With a narrow needle placing the 0402 is simple and accurate, you just dump it into the paste and it sticks. Also, unlike tweezers, vacuum pickers can pick the part in arbitrary orientation.

author: robrenz
author_rank: Super Contributor
timestamp: January 01, 2015, 05:31:30 pm
content: Quote from: KD0CAC John on December 31, 2014, 04:49:01 pmAgreed!

author: Howardlong
author_rank: Super Contributor
timestamp: January 01, 2015, 05:42:24 pm
content: When doing pasted boards, down to 0402, I use an illuminated magnifying lamp. Far faster than a microscope as you have a greater field of vision. After a few boards, you get to "know" the board pretty well, particularly if it's your own design, and if they're panellised the rate is even faster. On one occasion I placed about 3,600 parts in a day, 90% 0402. I wouldn't recommend trying to maintain that though, makes you go like this: