Printed circuit board to be needed

[showmy]

I have sent some PCB designs to factories for prototyping. The price, however, varies greatly. Some ask 200USD for a four-layer 5cm*10cm PCB prototyping. While some only ask for 50USD. I assume that there are differences between these two factories. However, I could not find the differences. Could I ask for some advice here?

 

[Old Steve]

I have sent some PCB designs to factories for prototyping. The price, however, varies greatly. Some ask 200USD for a four-layer 5cm*10cm PCB prototyping. While some only ask for 50USD. I assume that there are differences between these two factories. However, I could not find the differences. Could I ask for some advice here?

Where are the factories located?

Have you seen examples of their finished PCBs?

Are you sure they all both clearly understood your requirements?
(I just realised that, despite your phrasing, using the word "some", you only contacted two manufacturers.)

 

[showmy]

Where are the factories located?

Have you seen examples of their finished PCBs?

Are you sure they all clearly understood your requirements?

I have sent them my application below
My application:

• Mixed signal circuit, with precise analog circuit(10pA precision) with MCU runs at 168MHz with internal clock. It uses a 20MHz SPI.
• Long term stability is a concern.

Even I have seen the example, how could I know the quality of a PCB?

I'd like to buy pcbs from China cause I heard they are cheap usually in China.

 

[Old Steve]

Hmmm. All I can suggest is that you mention the names of the two manufacturers you're considering and ask if anyone has had PCBs made by them, and what they thought of the quality.
Otherwise, we can't help you. How are we going to know the difference between the boards from two un-named manufacturers?

The alternative is to ask if anyone can suggest a good, but inexpensive, PCB manufacturer.

Edit: In the past, I have had boards made by this manufacturer, (IMP Printed Circuits) and they did a very good job. They have a factory in China, and in Australia:-
http://imppc.com.au/Home/tabid/516/Default.html

That was some years ago, though. Nowadays I only do very small runs of SS boards, so make them myself.

 

[showmy]

Hmmm. All I can suggest is that you mention the names of the two manufacturers you're considering and ask if anyone has had PCBs made by them, and what they thought of the quality.
Otherwise, we can't help you. How are we going to know the difference between the boards from two un-named manufacturers?

The alternative is to ask if anyone can suggest a good, but inexpensive, PCB manufacturer.

Edit: In the past, I have had boards made by this manufacturer, (IMP Printed Circuits) and they did a very good job. They have a factory in China, and in Australia:-
http://imppc.com.au/Home/tabid/516/Default.html

That was some years ago, though. Nowadays I only do very small runs of SS boards, so make them myself.

I really appreciate that. Thank you very much!

 

[showmy]

I'll take the advice of the upfloor adviser.
The fisrt one I contact is raypcb.com. I googled it out. They stressed their quick express.I think they are professional.
The second one is 3pcb(http://www.3pcb.com/). I also heard there is 4pcb(http://www.4pcb.com/), but I haven't used it. 3pcb is also located in China, near my location relatively. They stessed their high quality and low price. It really attracts me. But I am not sure if it is true. Has anyone ever bought PCBs from 3pcb?
You can click the links to check if you have used them.
I'll also appreciate it if anyone can suggest other good manufacturers for me.

 

[Supercap2F]

Have a look at the website: www.pcbshopper.com. If you type in your requirements they will give you a list of cheapest to most expensive manufactures who will make your board. They also have a lot of reviews for each place.
Dan

 

[Arouse1973]

I haven't used them but I have seen the quality of them and for us in the UK the price is good. The quality is also good.
http://www.pcbcart.com/?gclid=CJCcyObw7McCFc8aGwodkD8L_g
Thanks
Adam

 

[ethila]

Some key things to look for:

• Test. Are they providing 100% connectivity testing on the boards after manufacturing?
• Delivery time. Many low cost fabs require several weeks to schedule and build your boards. Three-day turn-arounds cost much more.
• Will they respect your requirements (fab notes), or just build to a standard set of tolerances and specs? Many low cost vendors severely limit what they will accept in fab notes.
• Quality. Do you trust this shop to build your board right the first time, or is there a chance they'll mess it up and have to re-do it, causing a delay?
• Lower-level materials. Are they buying the actual laminate materials from high quality vendors or just whatever's cheapest at the moment. (Does your application need the higher-quality material?) Will they use the same material for every lot? If they're just buying at lowest cost, the product is likely to vary from lot to lot.
• Support. Are they providing engineering support to review your design and catch mistakes (mostly your layout mistakes) before you spend money on the fab.
• Certifications. Can the provide UL 94V-0 fire resistance certification on your boards?
• Capacity. When your prototype works and you're ready to build 1000, 10,000, or 100,000 boards per month, can they support you?

As for the factors mentioned above, I suggest you choose 3pcb(http://www.3pcb.com/). I have bought pcbs from them for my own projects. I am satisfied with their delivery, quality and service. I'm sure you'll be too.

Should I care the plating? I noticed different processes using tin/gold/Pb and etc.

 

[davenn]

Should I care the plating? I noticed different processes using tin/gold/Pb and etc.

There shouldn't be any lead used these days. Any decent manufacturer would be following the RoHS standards