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I'd like to mount a small (2.5") graphic LCD or OLED display on a PCB. I believe it should look something like this:

Evalbot pic cropped

I've seen this done (links to pics) on my LM3S6965 development kit, on my TI Evalbot, and on this Sparkfun breakout board. All of those images show a pane of glass, the screen itself, an FFC folded underneath the board, and very little information about the mounting technique. The LM3S6965 and Evalbot have a bit of foam visible underneath. (I can't speak to the Sparkfun board as I don't own it).

I suspect that the display is adhered to the PCB with double sided tape or an epoxy.

  1. Am I correct in my suspicions, or is there another method of doing this? I've considered cutting a relief out of some clear acrylic and screwing that to the PCB as an alternative.
  2. Is it removable? I've considered using a solvent or some force. I'm interested in trying out the screens I already own on other PCBs, and I'm also interested in replacing the screen on my new PCB if I break it or doing edits to the PCB beneath the display.
  3. Is it easy to do? I'd like to distribute the PCB with the components (including the display) as a kit to other engineering students, and I don't want them to have to deal with complex epoxy mixing ratios or risk damaging the LCD in the process.
  4. Is replicating this technique the right thing to do for a development board or in-house tool? I expect users to abuse or break this board, and I expect it to need rework.
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  • \$\begingroup\$ Technically, on the pictured 'LCD' (the evalbot), it's an OLED display ;) \$\endgroup\$
    – pfyon
    Feb 1, 2011 at 13:38
  • \$\begingroup\$ @pyfon - Yeah, sure, and the same with the LM3S6965, but it's the same mounting system (I think). \$\endgroup\$ Feb 1, 2011 at 14:14
  • \$\begingroup\$ If the board is going to be abused and you'll need to rework them, then the plastic cage fceconel sounds like a good approach, though you might have to find someone local to print them for you. I'd post in the Makerbot / Thingiverse google group to see if anyone can help you out. I can help but I'm not local. Otherwise, if you have access to a laser cutter, I would consider laser cutting some acrylic bread and sticking your LCD and PCB meat inside. Cut holes where the buttons and screen are, just big enough to capture the LCD. The MeggyRGB is a good example for buttons. \$\endgroup\$
    – Dave
    Feb 1, 2011 at 17:28
  • \$\begingroup\$ Actually, you can completely sandwich it since you're not using a touchscreen. A little double-stick would be nice to keep the LCD from shifting too much. \$\endgroup\$
    – Dave
    Feb 1, 2011 at 17:29
  • \$\begingroup\$ @Dave - I have access to CNC machines, commercial rapid prototyping machines, and laser engravers (not cutters - it chokes on anything much thicker than mylar) at school, but thanks for the offer! What is acrylic bread? A google search returns plastic boxes for holding loaves of bread. \$\endgroup\$ Feb 1, 2011 at 18:03

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Usually LCD displays come in a plastic "cage" that has pins (more precisely, bumps - they are very short) on each corner of its back. The PCB has holes to fit in, but that's just to prevent the display from sliding horizontally on the board. The board is then attached someway (screws, etc.) against the case "top" which has a window for the display, a little smaller than it in each dimension, and that holds it in place. Usually there's no need for an adhesive or glue, which also makes repair easier; just the LCD ribbon is really mechanically attached to the board. But for hobby projects there's nothing that prevents you to do so.

There are other, less popular methods. Displaytech's "LCD Connection Methods" document has a few diagrams, but it's not possible to attach a file here in .pdf format. In a roundabout conversion method, it's now on E&R's imgur account here, sorry for the low quality.

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  • \$\begingroup\$ If the displays I am looking at don't come with this cage, do I have to make my own, or is there a place I can buy these in various (possibly custom) sizes? \$\endgroup\$ Feb 1, 2011 at 17:03
  • \$\begingroup\$ I don't think that you'll find it easily in the market, they are usually manufactured in conjunction with the display. If they're available, the same site that sells the display will show it as an option/accessory. One option is to make in acrylic, you can find easily anywhere workshops that can cut/bend/punch acrylic sheets to your needs at a reasonable price. \$\endgroup\$
    – fceconel
    Feb 1, 2011 at 17:22
  • \$\begingroup\$ BTW, the link to the document is www.displaytech.com.hk/pdf/LCDConnectionMethods.pdf . Unfortunately I tried to access it and the site says it's temporarily unavailable; BUT Google cache still has it, do a search for the doc name and click on the 'cached' link. \$\endgroup\$
    – fceconel
    Feb 1, 2011 at 17:24
  • \$\begingroup\$ Great, thanks! I put a copy of the cached version in your answer, hope you don't mind. \$\endgroup\$ Feb 1, 2011 at 17:56
  • \$\begingroup\$ Not at all, glad you found it. \$\endgroup\$
    – fceconel
    Feb 1, 2011 at 18:13

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