Friday Free Board Quiz – PCB materials – the prize is MOD-WIFI-R5370-ANT


MOD-WIFI-R5370-ANT is USB WiFi module which works with all OLinuXino Linux computers.

It can be used for normal desktop PCs also.

To participate in the Quiz is enough to re-tweet the Twitter Quiz announcement message.

To double your chances you have to answer the Quiz question :)

The Quiz question is: Why there are no Double Sided or Multi layer PCBs made with FR-2 material?

You have time to re-tweet and/or answer until Monday 14th of December.

In Monday we will post the correct answer and ask to generate random number in range then announce the winner and ship the board by post/airmail.

Good Luck!

7 Comments (+add yours?)

  1. stefanstefanov198
    Dec 11, 2015 @ 16:59:31


  2. stefanstefanov198
    Dec 11, 2015 @ 17:11:18

    FR-2 is not strong enough to support VIA


  3. zoobab
    Dec 11, 2015 @ 18:11:44

    Do you know if rt5370 supports packet injection, like for aircrack-ng?


  4. LIME-fan
    Dec 12, 2015 @ 11:05:46

    Actually it would be possible to make FR-2 double sided and in the past some cheap consumer products were made of single or double sided FR-2 because the material is really cheap.

    But its max temperature of 70°C is today not usable for everything concerning microelectronics. If exceeded, the copperlayer starts to lift up from the base material and cracks easily. Your PCB really should be the last thing to die (exept you intentionally use it as a fuse) if your chips are getting hot 😉
    Same for vibrations and mechanical stress.

    Also its surface leakage and insulation resistance is much worse than FR-4 so it would not be possible to build a working A20-LIME2 board with FR-2.


  5. LinAdmin
    Dec 12, 2015 @ 22:11:58

    Sorry to contradict: Decades ago I have myself designed low cost dual sided PCBs manufactured with FR-2!


  6. LinuxUser
    Dec 14, 2015 @ 04:36:48

    Humm? I’ve seen some old dual layer PCBs made of FR2. Though FR2 these days only being used for cheapest, lowest grade devices, which are usually ok with just 1 layer + few jumpers.

    From what I know, FR2 haves some technoloigical issues when it comes to making vias. I guess there’re some issues with plating vias on such a crappy material – probably copper just does not lays properly and it does not gets reliable via connection on its own. Boards I’ve seen were using actual pieces of wire to do all layer interconnections and lacked plating in their vias.


  7. Bib
    Dec 14, 2015 @ 14:25:00

    The material FR-2 is not ductile therefore it can crack easily especially on the metalization of via under mechanical stress (or copper tracks delamination).
    In addition dunno if the material could sustain the laminate process for multilayer PCB (Heat !!).



Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out /  Change )

Google+ photo

You are commenting using your Google+ account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )


Connecting to %s

%d bloggers like this: