What is an ultra-thin PCB?

The normal thickness of PCB is 1.0 mm to 2.0 mm. The ultra-thin printed circuit means that the thickness of the printed circuit board is thinner than that of an ordinary PCB. Generally less than or equal to 0.6mm PCB we call thin PCB, 0.1mm-0.4mm can be called ultra-thin PCB.  

Sometimes, due to the limitation of space or margin, or the need for design purposes, people need thinner thickness (such as 0. 25 mm, 0. 20 mm, or even 0. 1 mm), so that PCB can be used for SIM card and sensor card. As a result, a very thin PCB or extra thin PCB appears. With the market demand for thinner devices, people try to make the design more portable, lighter, and more flexible, so the application of ultra-thin PCB is more and more widely.

For ultra-thin PCB, we can make it into 0.15 mm, 0.20 mm, 0.25 mm, 0.30 mm, with or without solder mask, the copper thickness of 1 / 2oz, 1 oz, 2 oz, 3 oz.

Thin PCBs with many thicknesses, such as 0.075mm, 0.1mm, 0.127mm, 0.152mm, 0.18mm, 0.2mm, 0.22mm to 0. 6mm, have many different materials. It depends on what material you need. We can use flex core material and FR4 core material. And BT core materials. Or other PCB materials.

FR4 thin PCB and flex PCB

The ultra-thin FR4 PCB can be made as thin as a flexible PCB and can be bent like a flexible circuit, but it is more robust and cheaper than the same copper trace on each board. Of course, flexible materials and BT materials can also be made into PCB with very thin board thickness.  If the thickness of the circuit board you need is less than 0. 10 mm, you should use a flexible circuit.  For 1L FPC, its thickness can be 0. 06 mm; For 2L FPC, the thickness can be 0. 10 mm.  

Surface treatment

Choosing a very thin PCB thickness may limit the choice of available surface treatments. According to the material characteristics and production methods, each surface finish has a different manufacturing process. Our standard immersion gold finish does support PCB with a minimum thickness of 0.1 mm

Production fixture

Ultra-thin PCB production means the need for special equipment, such as special cutting machines, the production of thin plate racks, horizontal conveyors,s and so on need special fixtures.

Application of ultra-thin PCB

The product is mainly suitable for RFID smart card

IC card

ID key chain

SIM card

Contact smart card

And electronic tags

NFC technology and equipment

Mobile phone charging module

wearable devices

Drawing board

Metro coin

Ultra-thin board capacity

Base material: FR4 TG 130, TG 170, TG 180

Board thickness: 0. 1 ~ 0. 3 mm (0. 004 "~ 0. 012")

Copper thickness: 0. 5 oz, 1 oz, 2 oz, 3 oz

Overview: milling, drilling, V-cutting, laser cutting

Surface treatment: ENIG, OSP, ENEPIG

Maximum panel size: 500 * 500 mm (19. 68 "* 19. 68") or 1000 * 350 mm (39. 37 "* 13. 77")

Minimum panel size: 3. 5 * 3. 5mm (0. 137 in * 0. 137 in)

Minimum single size: 25 * 25 mm (0. 984 "* 0. 984")

Minimum through hole: 0. 1 mm

Minimum trace space / width: 4mil / 4mil

Packaging: Vacuum

Sample lead time: 7-9 days

The manufacturing process of the ultra-thin board is almost the same as that of ordinary FR4 PCB board, but because it is thinner, each manufacturing process will be controlled more carefully and accurately, and different manufacturing equipment will be used for some processes, so as to ensure the smooth processing of ultra-thin board in this process.

FAQ of ultra-thin PCB

The following are the FAQs and answers of our customers' ultra-thin PCB.  I hope this information can help you understand Rocket PCB. If you have more questions about the design and production of ultra-thin PCB, please feel free to consult us.  

Question 1: what is the minimum thickness of a single PCB?

A1: ≥ 0. 1MM + / - 0. 05mm

Question 2: what is the minimum thickness of a double-layer PCB?

A2: ≥ 0. 15mm + / - 0. 05mm

Question 3: what is the minimum thickness of Multilayer PCB?

A3: for 3L: minimum thickness 0. 3mm±05 mm;

For 4 layers: minimum thickness of 0. 35 mm + / - 0. 05 mm;

For 6 layers: minimum thickness is 0. 6 mm + / - 0. 08 mm.

Question 4: can BGA be fabricated on ultra-thin PCB?

A4: Yes, if your board is BGA, the minimum through-hole requirement is 0. 2mm. If the vias in the pad don’t need to be filled with anything, then we can make 0. 15mm minimum vias.

Q5: Can you control the impedance on the ultra-thin PCB?

A5: Yes, we can.

Q6: what is the difference between FPC and ultra-thin PCB?

A6: different materials. FPC is made of polyimide (PI). The ultra-thin PCB is made of FR4 material.

1）FPC is more flexible and can be bent many times under the minimum bending radius.  Ultra-thin PCB can also be bent, but the bending radius is not fixed, especially in a very small size.

2）Ultra thin PCB is cheaper than FPC.

Question 7: what kind of surface treatment can be used for ultra-thin PCB?

A7: OSP, tin, gold (AU 1U’’ - 2U’’), ENEPIG

Q8: What is the common thickness of ultra-thin PCB?

A8: the common thickness of ultra-thin PCB is 0. 1mm to 0. 6mm.  The common copper thickness we can manufacture is 0. 5oz (17um), 1oz (35um), 2oz (35um).  We can also manufacture 3oz (105um), but the materials need to be customized and the delivery time is longer.

Q9: What is the common thickness of solder masks?

A9: it’s 10-25um.  We can make it 30-40um thick.

Q10: What is the longest size of ultra-thin PCB?

A10: the longest size we can make is 1000mm x 350mm,

Q11: What is the maximum size of ultra-thin PCB?

A11: the maximum size we can make is 500mm x 500mm.

Q12: What is the minimum size of ultra-thin PCB?

A12: the minimum size we can make is 3. 5mm * 3. 5mm (panel delivery).  If it is single-piece delivery, the minimum size we can make is 25mm * 25MM.

Q13: because the ultra-thin PCB is very thin, how do you control the via tolerance?

A13: we will control each manufacturing process:

1）Before drilling, the number of stacking layers should not be too many.  For 0. 15mm PCB, the maximum number of layers is 12.

2）Before drilling, we will use aluminum to protect the raw materials at the top of the board to dissipate heat during drilling, and put the board at the bottom of the board to fix the board.

3）We will control the use of the drill bit, maintain the drill bit regularly, and each drill bit will exit after 1000 times.

4）Control the position tolerance of via within + / - 3 mils

Q14: What are the minimum routing width and spacing of ultra-thin PCB?

A14: we can make the smallest routing width and space for our ultra-thin PCB in 4mil / 4mil.

Q15: What is the minimum through-hole of the smallest PCB?

A15: we can drill the smallest hole within 0. 2mm. If your through-hole does not need to be filled, we can set it to 0. 15mm.

Q16: Can tape is pasted on the surface of ultra-thin PCB?

A16: Yes, we can paste adhesive tape on ultra-thin PCB.  For ultra-thin PCB, two kinds of adhesive are recommended, namely 3M467 and 3M9077. 3M467 is suitable for normal temperature (121 ℃) and 3M9077 is suitable for high temperature (150 ℃).

Q17: How do you test ultra-thin PCB?

A17: in general, if the board area is less than 1 square meter, we will use flying needles for testing. If the board area is more than 1 square meter, we will set up a test fixture for testing.

Q18: What is the delivery time of ultra-thin PCB?

A18: the delivery time of ultra-thin PCB prototype is 7-9 days, and the mass production is 2-2. 5 weeks.  

Summary

Rocket PCB is a professional manufacturer of ultra-thin PCB circuit boards, the thinnest single-layer board can be 0.08m, double-layer board 0. 13M, four-layer board 0. 35m.  The production technology is far ahead in the industry! Products are mainly for the Internet of things industry. The main production of smart card M1, ID, 4001 product substrate, and induction copper coil PCB substrate. Products are widely used in all kinds of intelligent sensing industries, such as intelligent access cards, subway tickets, anti-metal cards, intelligent electronic license plates, NFC wireless payment, etc.