Hi Arsenijs! > A common practice is also putting the connector on the other side of > the PCB, then making a slot which the cable is supposed to go through. > This way, you don't have to worry about LCD and the connector > occupying the same space.
Startek folks (one of the two LCD vendors I am working with) suggested the same idea to me. I suppose this idea might work if there is a great scarcity of electronics on the board: if the entire logic of the phone is in one chip (no wide external memory buses, no chipset internal interconnections) and the LCD is used in the SPI interface mode, connected to the all-in-one chip with just a few wires, then there would be plenty of room on the back side of the board, and the slot can probably be made in the middle of the PCB without totally crippling the signal routing ability. I suppose this idea could work for those 100% closed and proprietary "modern" dumbphones based on MTK or Spreadtrum chips. But this idea will NOT work for our FreeCalypso handset. Our PCB will have 8 layers with lots of traces on every layer (intricate 2+4+2 HDI structure with inner buried vias and two levels of staggered microvias on each side), and the width of the PCB will extend only slightly past the width of the LCD module. If we had to cut a slot the width of the LCD's FPC tail in the middle of our PCB, it would cut through all of our layers and present an obstacle for signal routing, completely crippling our PCB layout. In short, just no - totally not suitable for a PCB of our complexity. I already know what I want, and I will not settle for anything less: I want an LCD whose FPC tail is meant to be soldered rather than connectorized. Both Startek and HaoRan said they can make such, but with an MOQ of 1000 pcs, which would be about $3200 at HaoRan's prices or about $5600 at Startek's prices. It is more than I can afford right now, so for the first prototype I will have to use a dirty hack (lift the existing connectorized LCD above the PCB with double-sticky tape to make room for the connector), but at a much later stage of the project (after the first prototype has been built and the software has been brought into shape) I will probably have to just bite the bullet and pay the 1000 pcs price to get the LCDs I really want. For the first prototype I am thinking of my particular hack with the double-sticky tape to lift the LCD as opposed to some other dirty hack in order to make our PCB design as close as possible to what I ultimately desire with a solder-down LCD: this way when we do get the good LCDs, the layout change will be absolutely minimal. But meanwhile I need to build some kind of test rig for HaoRan's LCD (it's a one-off hack, so it doesn't matter how hacky or dirty or ugly it is) so I can visually compare the picture quality between HaoRan and Startek LCDs. I seek an LCD of the very highest picture quality, hence the decision between HaoRan and Startek will need to be based on whichever LCD produces the best picture quality. I already know from having tested it that Startek's LCD is very good, but I have yet to see HaoRan's. Thus I need a test rig for HaoRan's LCD so I can do the comparison. I expect to be picking up these HaoRan LCDs from the mailbox service later today, and then I will need to start the dialogue with Hirose (the FPC connector manufacturer) about the straight vs. tapered FPC end strangeness. If Hirose folks say that a straight FPC end cannot be reliably inserted into an FH33 series connector and that it is some kind of inexplicable accident that Foxconn somehow got it to work in the Pirelli DP-L10, then I'll just use the taller FH12 series connector for the HaoRan LCD evaluation board - but if there is some way to use FH33, I would like to use that as it would be very helpful for the handset prototype: it's bad enough already that we'll have to use double-sticky tape to lift the LCD, and having to use an even taller connector than the one in the Pirelli phone would be even worse. M~ _______________________________________________ Community mailing list Community@freecalypso.org https://www.freecalypso.org/mailman/listinfo/community