Hello Xiaofan, >I am now in Singapore. Singapore is in Southeast Asia and the majority > of the population are Chinese but there are quite some Malay and > Indian as well. Sorry, I guess I could have found that out from your signature in one of your previous posts.. yes, I know a little bit about Singapore - we have a distributore there, and it's a popular example in books on Economics and International Business. The first things that come to mind are exports exceeding GNP by something like 40%, high-tech economy, very high per capita GNP, and Singapore's ingenious solution to traffic jams. The traffic jam solution is my favorite, I cite it every time someone complains that we don't have enough freeways in Phoenix. Unfortunately, free rider mentality prevails, but that's a topic for another discussion. ;) > We are doing mass production but not in the sense of mass production > in the consumer electronics. Most of our product have annual quantity > of 1k to 20k with very few product above 50kpcs per year. I am told > by the SMD/PTH department that a PTH machine is not worth the initial > investment since majority of components are SMD parts here and the > direction is going to smaller and smaller parts. Very wise. As complexity of our products continues to increase, PTH becomes uneconomical. And since SMT is not as labor-intensive, competitive advantage of Chinese manufacturers is greatly diminished. We're actually considering moving production back to the States - lead times are shorter, and quality is better. > We have more than 600 > people in Singapore and another 300 people in a nearby subsidy > in Bintan Island, Indonesia. It is quite expensive to do manual insertion > and soldering in Singapore (of course still cheaper than in the > headquarter in Mannheim, Germany). But in Bintan (similar to China in the > aspect of cost but without the high quality work force but it is > only one hour to Singapore), the price is quite cheap. May I ask what would be an average worker's salary in Bintan and Singapore? Our Chinese contract manufacturer said their engineers' and workers' salaries are $500 and $100/month, respectively. Not sure if that's typical, though. > We have quite some SMD machines though and they are not cheap especially > when the accuracy of placement is high. Most of them are Siemens Siplace > machines. They are really quite expensive. I can imagine! > We do not have Computerized > Vision Inspections system either. Therefore we are doing manual visual > check (with microscopes) of the quality of SMD reflow soldering. The manufacturer I mentioned in my previous message does have such a system, and it's pretty cool to watch it in operation. :) Of course, it makes sense - you are building small quantities of many different (and I assume, frequently changing) devices, rather than vast quantities of the same product. It takes time to "learn" a new circuit board. > The number of vias may affect the PCB price. This is especially true when > the size of the vias is quite small. So you need to do some calculations. I realize that the answer to my original question depends on several factors, and the best way to know for sure is to ask the manufacturer. However, I was hoping that someone has developed a rule of thumb for deciding whether to have lots of vias, or place SMT parts on both sides of the boards. As far as I understand, one has to know the difference in costs of: 1. Applying the solder paste to the second side, and running the board through the reflow oven a second time, and 2. Number of extra vias multiplied by the cost per via. If there aren't many extra vias, it is obviously cheaper to have parts on one layer - since the the costs of applying the paste and running the board through the oven remain constant, regardless of the number of components per side. > However PCB price are generally more depending on the quantity and > tolerance and the number of milling and V-cut than the number of vias. > PCB price negotiation is quite difficult when the quantity is low. > We try to procure PCBs from mainland China. However, those with good > quality does not accept our order quantity and price. Those accepting > our order quantity/price does not meet our quality requirement. ;-( You can console yourself with the thought that your direct competitors are in the same boat. ;-) Best regards, Vitaliy > -----Original Message----- > From: Vitaliy > Sent: Monday, October 17, 2005 2:24 PM > To: Microcontroller discussion list - Public. > Subject: Re: [EE] Board Manufacturing > > A very interesting discussion! > > Xiaofan, when you say > >> [...] we do not have automatic placement machine for >> PTH components since manual insertion is still cheaper. > > I assume you're talking about a Chinese factory? Is an automatic placement > machine more expensive because of high operating costs, or do you mean > that > in the sense that it requires a substantial initial investment? > > If I remember correctly, on my visit to our contract manufacturer I was > told > > that their state-of-the-art pick-and-place SMT and PTH machines were $300k > apiece. Perhaps what you said would only apply to (relatively) small > factories, which are unable to use the machine to its full capacity? > > We just sent the Gerbers for our latest product to the board house on > Friday. This particular PCB has SMT on both sides, with PTH LEDs, IC > socket, > > and sub-D connectors on the top. Although initially we were able to > jam-pack > > the parts on one side, the resulting number of vias was ridiculous - IIRC, > x3 or more compared to the two-sided approach. > > So here's a question for people with more experience: is it better > (cost-/performance-wise) to have SMT parts on both sides, or have three > times as many vias? > > Best regards, > > Vitaliy > -- > http://www.piclist.com PIC/SX FAQ & list archive > View/change your membership options at > http://mailman.mit.edu/mailman/listinfo/piclist > -- http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist