Here are Frequently Asked Question (FAQ) and Answers of Extra Thin PCB from our customers, hope the information will be helpful for you to understand more about extra thin PCB from Best Technology.

• Q1: What’s your min thickness for single layer PCB?
  A1: ≧0.13 mm+/-0.05 mm (base on solder mask on one side)
• Q2: What’s your min thickness for double layer PCB?
  A2: ≧0.15 mm+/-0.05 mm
• Q3: What’s your min thickness for multilayer PCB?
  A3: For 3L: min thickness is 0.3 mm+/-0.05 mm;
  For 4L: min thickness is 0.35 mm+/-0.05 mm;
  For 6L: min thickness is 0.6 mm+/-0.08 mm.
• Q4: Can BGA to be made on your extra thin PCB?
  A4: Yes, if your board make BGA, the min vias required to be 0.2mm. If your vias in PAD no need to be filled anything, then we can make the min vias in 0.15mm.
• Q5: Can you control the impedance on extra thin PCB?
  A5: Yes, we can do that.
• Q6: What’s the difference between flex PCB (FPC) and extra thin PCB?
  A6: The materials are different. FPC is made of Polymide (PI). Extra thin PCB is made of FR4 material.

  1)FPC is more flexible, and you can bend it many times at minimum bending radius, extra thin PCB also can be bendable, but it does not have fixed bending radius, especially in very small size.

  2)Price for extra thin PCB is cheaper than FPC.

• Q7: What types of surface finishing are available for extra thin PCB?
  A7: OSP, Immersion Tin, Immersion Gold (Au 1u’’-2u’’), ENEPIG
• Q8: What’s the common thickness for extra thin PCB?
  A8: The common thickness for extra thin PCB is 0.15mm to 0.6mm, the common copper thickness we can make is 0.5oz (17um), 1oz (35um), 2oz (35um), we can also make 3oz (105um), but the materials need to be customized and lead time is much longer.
• Q9: What’s the common thickness of the solder mask?
  A9: It is 10-25um, we can make the thickness up to 30-40um.
• Q10: What’s the longest size of your extra thin PCB?
  A10: The longest size we can make is 1000mm x 350mm,
• Q11: What’s the biggest size of your extra thin PCB?
  A11: The biggest size we can make is 500mm x 500mm.
• Q12: What’s the smallest size of your extra thin PCB?
  A12: The smallest size we can make is 3.5mm*3.5mm (shipment by panel) If shipment by single pieces, the min size we can make is 25mm*25mm.
• Q13: As the extra thin PCB is very thin, how do you control the via tolerance?
  A13: We will control each manufacturing process:

  1) Before drilling, the numbers of the stacked layers can’t be too high, for 0.15mm PCB, maximum layers will be 12.

  2)Before drilling, we will protect the raw materials with aluminum on top of the boards to dissipate heat while drilling, and put the wooden board on bottom of the board to make the board well fixed.

  3)We will control usage of of the drill, regular maintenance of the drill bit, each drill bit will be withdrawn after 1000 times.

  4) Control the vias position tolerance within +/-3 mil

• Q14: What’s the min traces width and space for your extra thin PCB?
  A14: We can make the min traces width and space for our extra thin PCB in 4mil/4mil.
• Q15: What’s your min vias for extra thin PCB.
  A15: We can make the min drill in 0.2mm. If no filling is needed for your via, then we can make it as 0.15mm.
• Q16: Can you put adhesive tape on surface of extra thin PCB?
  A16: Yes, we can put adhesive tape on the extra thin PCB, there are 2 kinds adhesive are recommended for extra thin PCB, 3M467 and 3M9077. 3M467 is suitable for the normal temp (121 C), and 3M9077 is good for high temp (150 C).
• Q17: How did you make the testing for the extra thin PCB?
  A17: Normally, if the boards area is smaller than 1 square meters, we will use the flying probe for testing. If the boards area is bigger than 1 square meters, we will set up a testing fixture to do the testing.
• Q18: What’s your lead time for the extra thin PCB?
  A18: Lead time for prototype of extra thin PCB will be 7-9 days, for mass production will be 2-2.5 weeks.

If you found out mistake in above FAQ, or have more questions of extra Thin PCB need to be answered, please contact us immediately. Best Technology will answer your email within 12 hours!