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I am developing a new open source device which consists of several functionalities. My plan is to get it printed from a PCB manufacturing company and get it assembled from the same company. I have discussed with several people and came up with the following options. Please note that the device has 150+ components and 350+ nets.

  1. Develop the PCB as a 4 layer PCB and components on both sides. (Size : Arduino Uno)

I have tried obtaining a quotation from seeedstudio and for 100 boards, total cost was estimated as USD 4994.26

  1. Develop the PCB as 2 layer PCB and components on one side. (Size : Arduino Mega)
  2. Develop the PCE as 2 layer PCB and components on both sides. (Size : Arduino Mega)

For the above two cases, it was quoted as USD 4878.23

So my question is this; In production, if we place components on both sides, does it have a major impact in the cost and the process? (As the boards need to be turned to solder the other side etc.)

Edit!

I am adding more details about the PCB. The PCB is a device with a 16 bit PIC microcontroller (TQFP44) which acts as the main processing unit. All the components are SMD. It has a UART bridge(MCP2200) and a couple of OpAmps (SOIC8) to generate sine waves, square waves and a ADC chip with a few voltage doublers and inverters to provide functionalities such as a 4 channel oscilloscope, 4 channel logic analyzer and expansion slot for an ESP chip. The device can be connected to a computer via a USB cable and with the use of a desktop application users can interact with the device.

Padmal
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    You already have your answer, 4994 plays 4878. However, I suspect most of that cost is dominated by one time setup fees, so you don't really see the actual per unit assembly cost. Double sided components don't need the board flipping over if they're SMD components held on with glue dots. It depends whether the mnfr has this equipment or not, how he'll quote you. Palletising to get big repeated boards lowers per unit cost but increases the setup problem of low quantities, so it may or may not help. Quantity is very important, 100off quote will not inform a 100koff decision. – Neil_UK Jan 03 '18 at 05:58
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    The question is: CAN you use a two-layer board? Because it's not possible to have ~100Ω impedance tracks on a two-layer board without needing ridiciously wide tracks and track separation. Do you need impedance-controlled tracks? – Janka Jan 03 '18 at 07:49
  • @Janka I wouldn't need impedance controlled tracks! – Padmal Jan 03 '18 at 09:29
  • This is too expensive. Pcb should not cost more than 800bucks. Components - i am not sure, but sounds quite high. Quote in China. –  Jan 03 '18 at 16:57
  • Ok, it's a pic board. I maybe it's a fair price, but maybe it's twice what it worth –  Jan 03 '18 at 17:02
  • This seems high for China. Was this their formal quote, or the instant quote? Have you tried other vendors? I've used Gold Phoenix in the past with good success. – Synchrondyne Jan 03 '18 at 17:08
  • Also, what's your component BOM cost when you plut it into Octopart? – Synchrondyne Jan 03 '18 at 17:10
  • @PeterK This is the quote I got from seeedstudio (which is a Chinese company) from their online tool. I asked them if the cost depends on the placement of components and they said that's not how they quote and it's quoted per number of components. I tried the BoM with mouser and it came out to be 1800 USD for 100 sets. And I tried PCBcart and their PCB printing cost is quiet high! – Padmal Jan 04 '18 at 08:40
  • Lots of options here that only the OP can resolve. Its his design and his money. VTC. –  Jan 04 '18 at 21:09
  • @Blogger Seeed and PCBcart really only work at prototype volumes though (up to dozens). I would try sending an RFQ to somebody who specializes in small production volumes, like Gold Phoenix. I just had a run of 300 boards done there, it was super cheap. – Synchrondyne Jan 04 '18 at 22:30
  • @Blogger also, I suppose we should have asked this earlier, but is your design mostly surface mount or are there through-hole components? Through-hole assembly is significantly more expensive than SMT. If your board can be fully SMT, that will bring costs way down (or almost fully SMT, with a couple of parts that get hand-soldered). – Synchrondyne Jan 04 '18 at 22:32
  • @PeterK the only TH components are the oscillator and some header pins. I should give those facts a try and update here! – Padmal Jan 06 '18 at 03:30

3 Answers3

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As for the cost: 4878.23 < 4994.26 so that is simple.

The 4-layer option is about 2% more per product. You don't tell us what type of product it is so I can't really judge, but I would go for the 4 layers as it will get a much better power and ground grid. Moreover with a continuous ground it'll have more chance of passing EMC.

Oldfart
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  • I have updated the question with details related to the PCB. Downsizing the 4 layers to 2 layers is quiet time consuming and I'm not sure if that's even possible as to the complex routing. – Padmal Jan 03 '18 at 09:23
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    You would likely spend the difference on EMC pain, the cost premium of 4 layers is pretty negligible these days, and the advantages are massive. Go with 4 layer even if going for single sided placement (Which actually you have not explored), the win is denser component placement and MUCH better EMC performance. – Dan Mills Jan 03 '18 at 13:35
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Check out Macrofab. They do turn key PCB manufacturing. More importantly, they have an online quote system which itemizes the cost, and allows you to compare different design options to your hearts content. I've found their prices to be very competitive for US based manufacturing.

Just spitballing I will say for a board of that size 50 per board at 100 qty is a reasonable price. I don't think you'll be able to get much lower than that without going directly to a Chinese manufacturer.

Drew
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You ask if having components on both sides affects the cost of assembly; but you answer your own question: "As the boards need to be turned to solder the other side etc.".

Take it as a given that additional processing steps always add cost. I assume the root of your question is if this additional cost can be reduced by using the smaller Uno form-factor? The difference between the Mega and Uno form factors is less than 3 square inches, so the price difference between the PCB material will be small.

Is your real question if the ~$49/piece is a reasonable price to pay? That depends on too many factors that you have not included.

spuck
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