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What is a 4 Layer Flex PCB?
You will have a lot of usage options with this type of multilayer Flexible PCB.
The usual Flex PCB applications are in line with the typical applications.
You’ll probably use this for mobile use, the semiconductor industry, or the medical industry.
This kind of circuit board’s flexibility makes it ideal for use in applications requiring a lot of repetitive bending.
Unbeatable 4 Layer Flex PCB Quality
Outstanding thermal conductivity and excellent insulation are both features of all our Flex PCBs.
Since PCBTok only uses premium materials, you can be sure that our products will last a long time.
Because our customers are so important to us, we always take into account their needs and demands.
Please get in touch with us right away if you require a custom flex PCB of any layer, not just 4-layered!
The company wouldn’t have lasted 12 years in the market if PCBTok’s products and services weren’t of the highest caliber.
4 Layer Flex PCB By Feature
With polyimide as the main material, surface finishes for this type of Flex PCB includes ENIG, ENEPIG and Immersion Silver.
The PTH is used for Flex PCB of many layers like this one. Some of these boards also feature microvias.
Mobile PCBs that are flexible are used in mobile devices, with smartphones and tablets serving as the best examples.
The DuPont corporation, which manufactures the Pyralux line for Flex PCB, is regarded as the top supplier of flex material.
You can order a variety of raw flex PCB materials that are used on multilayer boards too using the Taiflex brand.
4 Layer Flex PCB by Copper Thickness (5)
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The best quality of 0.5 oz PCBs, especially when combined with HTE foils, is signal integrity + lightweight characteristic.
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When choosing this type of PCB’s preferred thickness, a number of factors come into play. But most clients only use the 1 oz.
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This copper weight is the beginning of the heavier copper PCBs, which are not only for the rigid but also for the FPC.
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Suited for high power applications and power supply use, these match industrial/commercial purposes.
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People who want improved board solderability tend to request the 6 oz Copper Thickness, which is not very common.
What Materials are Used in the 4 Layer Flex PCB?
The best thing about this type of PCB is that no other design solution can fit where this product is shaped to fit.
There are components that must come together for this effectiveness to be achieved.
These are the components used to create this type of board.
- Mainly, polyimide
- Adhesive, like copper-clad flex laminate
- Coverlay, especially, when attaching this layer to a rigid board.
Most of the raw materials are usually sourced via a PCB manufacturer, or you can order them yourself from the PCB material supplier.
Explain the 4 Layer Flex PCB Stack-up
As a rule, the total thickness of the thinnest type of the 4 layer PCB is 0.282 (+/–.03mm). But there are other thicker options, as the thickest can reach 0.45mm.
Copper thickness matters because you need to factor in PCB trace and current carrying capacity.
The following make-up the PCB stack-up for this multilayer flex board:
- Coverlay (which is polyimide + adhesive)
- Copper trace + adhesive
- Another layer of Copper trace + adhesive
- Bottom layer of coverlay again
What are Applications for the 4 Layer Flex PCB?
The 4 Layer Flex PCB has a wide range of uses.
Many customers of this type of PCB have applied it to the following industrial sectors:
- Medical tools – those that need to be bent to fit MRI machines, probing tools, etc.
- Automotive use – these can be deployed for the engine, the entertainment system, etc.
- GPS and navigation tools – these can be wearable PCB types too
- Mobile devices, like the ubiquitous smartphone
- Commercial usage, like those in machinery and power modules
Where Do I Find a 4 Layer Flex PCB Manufacturer?
Flex PCBs like this one can be easily bent into any shape needed by the device’s design because they are so adaptable.
This is especially true for the 0.5 oz ones, which are the thinnest. They are simple to manufacture and assemble into finished products.
Especially when done by a skilled PCB fabricator—PCBTok is one such manufacturer.
They are additionally well suited to harsh environments thanks to your dedicated PCB maker.
Call us right away for your 4 Layer Flex PCB orders.
4 Layer Flex PCB Fabrication
Flex PCBs, particularly multilayer ones like this, are required for the task that are necessary in the digitalized world.
You will reap the following benefits if you use this type of board compared to Rigid PCBs:
- End-product miniaturization can be achieved
- It lasts in high temperature scenarios
- If the end product is used 24/7 non-stop, that is survivable too
- Microcontrollers, DiP (both ceramic and plastic types)
When using this number of Flex PCB layers, you must take the following factors into consideration.
First, there are issues with bending. Is your product a flex PCB that can be folded once and then installed? A dynamic Flex PCB product, perhaps?
Next, what is your PCB routing for this product, exactly? It must completely address electrical connections among all flex layers.
Finally, you might have to decide which PCB schematic software is best.
4 Layer Flex Production Details As Following Up
- Production Facility
- PCB Capabilities
- Shipping Method
- Payment Methods
- Send Us Inquiry
| NO | Item | Technical Specification | ||||||
| Standard | Advanced | |||||||
| 1 | Layer Count | 1-20 layers | 22-40 layer | |||||
| 2 | Base Material | KB、Shengyi、ShengyiSF305、FR408、FR408HR、IS410、FR406、GETEK、370HR、IT180A、Rogers4350、Rogers400、PTFE Laminates(Rogers series、Taconic series、Arlon series、Nelco series)、Rogers/Taconic/Arlon/Nelco laminate with FR-4 material(including partial Ro4350B hybrid laminating with FR-4) | ||||||
| 3 | PCB Type | Rigid PCB/FPC/Flex-Rigid | Backplane、HDI、High multi-layer blind&buried PCB、Embedded Capacitance、Embedded resistance board 、Heavy copper power PCB、Backdrill. | |||||
| 4 | Lamination type | Blind&buried via type | Mechanical blind&burried vias with less than 3 times laminating | Mechanical blind&burried vias with less than 2 times laminating | ||||
| HDI PCB | 1+n+1,1+1+n+1+1,2+n+2,3+n+3(n buried vias≤0.3mm),Laser blind via can be filling plating | 1+n+1,1+1+n+1+1,2+n+2,3+n+3(n buried vias≤0.3mm),Laser blind via can be filling plating | ||||||
| 5 | Finished Board Thickness | 0.2-3.2mm | 3.4-7mm | |||||
| 6 | Minimum Core Thickness | 0.15mm(6mil) | 0.1mm(4mil) | |||||
| 7 | Copper Thickness | Min. 1/2 OZ, Max. 4 OZ | Min. 1/3 OZ, Max. 10 OZ | |||||
| 8 | PTH Wall | 20um(0.8mil) | 25um(1mil) | |||||
| 9 | Maximum Board Size | 500*600mm(19”*23”) | 1100*500mm(43”*19”) | |||||
| 10 | Hole | Min laser drilling size | 4mil | 4mil | ||||
| Max laser drilling size | 6mil | 6mil | ||||||
| Max aspect ratio for Hole plate | 10:1（hole diameter＞8mil） | 20:1 | ||||||
| Max aspect ratio for laser via filling plating | 0.9:1(Depth included copper thickness) | 1:1(Depth included copper thickness) | ||||||
| Max aspect ratio for mechanical depth- control drilling board(Blind hole drilling depth/blind hole size) |
0.8:1(drilling tool size≥10mil) | 1.3:1(drilling tool size≤8mil),1.15:1(drilling tool size≥10mil) | ||||||
| Min. depth of Mechanical depth-control(back drill) | 8mil | 8mil | ||||||
| Min gap between hole wall and conductor (None blind and buried via PCB) |
7mil(≤8L),9mil(10-14L),10mil(＞14L) | 5.5mil(≤8L),6.5mil(10-14L),7mil(＞14L) | ||||||
| Min gap between hole wall conductor (Blind and buried via PCB) | 8mil(1 times laminating),10mil(2 times laminating), 12mil(3 times laminating) | 7mil(1 time laminating), 8mil(2 times laminating), 9mil(3 times laminating) | ||||||
| Min gab between hole wall conductor(Laser blind hole buried via PCB) | 7mil（1+N+1）；8mil（1+1+N+1+1 or 2+N+2） | 7mil（1+N+1）；8mil（1+1+N+1+1 or 2+N+2） | ||||||
| Min space between laser holes and conductor | 6mil | 5mil | ||||||
| Min space between hole walls in different net | 10mil | 10mil | ||||||
| Min space between hole walls in the same net | 6mil(thru-hole& laser hole PCB),10mil(Mechanical blind&buried PCB) | 6mil(thru-hole& laser hole PCB),10mil(Mechanical blind&buried PCB) | ||||||
| Min space bwteen NPTH hole walls | 8mil | 8mil | ||||||
| Hole location tolerance | ±2mil | ±2mil | ||||||
| NPTH tolerance | ±2mil | ±2mil | ||||||
| Pressfit holes tolerance | ±2mil | ±2mil | ||||||
| Countersink depth tolerance | ±6mil | ±6mil | ||||||
| Countersink hole size tolerance | ±6mil | ±6mil | ||||||
| 11 | Pad(ring) | Min Pad size for laser drillings | 10mil(for 4mil laser via),11mil(for 5mil laser via) | 10mil(for 4mil laser via),11mil(for 5mil laser via) | ||||
| Min Pad size for mechanical drillings | 16mil(8mil drillings) | 16mil(8mil drillings) | ||||||
| Min BGA pad size | HASL:10mil, LF HASL:12mil, other surface technics are 10mil(7mil is ok for flash gold) | HASL:10mil, LF HASL:12mil, other surface technics are 7mi | ||||||
| Pad size tolerance(BGA) | ±1.5mil(pad size≤10mil);±15%(pad size>10mil) | ±1.2mil(pad size≤12mil);±10%(pad size≥12mil) | ||||||
| 12 | Width/Space | Internal Layer | 1/2OZ：3/3mil | 1/2OZ：3/3mil | ||||
| 1OZ: 3/4mil | 1OZ: 3/4mil | |||||||
| 2OZ: 4/5.5mil | 2OZ: 4/5mil | |||||||
| 3OZ: 5/8mil | 3OZ: 5/8mil | |||||||
| 4OZ: 6/11mil | 4OZ: 6/11mil | |||||||
| 5OZ: 7/14mil | 5OZ: 7/13.5mil | |||||||
| 6OZ: 8/16mil | 6OZ: 8/15mil | |||||||
| 7OZ: 9/19mil | 7OZ: 9/18mil | |||||||
| 8OZ: 10/22mil | 8OZ: 10/21mil | |||||||
| 9OZ: 11/25mil | 9OZ: 11/24mil | |||||||
| 10OZ: 12/28mil | 10OZ: 12/27mil | |||||||
| External Layer | 1/3OZ：3.5/4mil | 1/3OZ：3/3mil | ||||||
| 1/2OZ：3.9/4.5mil | 1/2OZ：3.5/3.5mil | |||||||
| 1OZ: 4.8/5mil | 1OZ: 4.5/5mil | |||||||
| 1.43OZ（positive）:4.5/7 | 1.43OZ（positive）:4.5/6 | |||||||
| 1.43OZ（negative ）:5/8 | 1.43OZ（negative ）:5/7 | |||||||
| 2OZ: 6/8mil | 2OZ: 6/7mil | |||||||
| 3OZ: 6/12mil | 3OZ: 6/10mil | |||||||
| 4OZ: 7.5/15mil | 4OZ: 7.5/13mil | |||||||
| 5OZ: 9/18mil | 5OZ: 9/16mil | |||||||
| 6OZ: 10/21mil | 6OZ: 10/19mil | |||||||
| 7OZ: 11/25mil | 7OZ: 11/22mil | |||||||
| 8OZ: 12/29mil | 8OZ: 12/26mil | |||||||
| 9OZ: 13/33mil | 9OZ: 13/30mil | |||||||
| 10OZ: 14/38mil | 10OZ: 14/35mil | |||||||
| 13 | Dimension Tolerance | Hole Position | 0.08 ( 3 mils) | |||||
| Conductor Width(W) | 20% Deviation of Master A/W |
1mil Deviation of Master A/W |
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| Outline Dimension | 0.15 mm ( 6 mils) | 0.10 mm ( 4 mils) | ||||||
| Conductors & Outline ( C – O ) |
0.15 mm ( 6 mils) | 0.13 mm ( 5 mils) | ||||||
| Warp and Twist | 0.75% | 0.50% | ||||||
| 14 | Solder Mask | Max drilling tool size for via filled with Soldermask (single side) | 35.4mil | 35.4mil | ||||
| Soldermask color | Green, Black, Blue, Red, White, Yellow,Purple matte/glossy | |||||||
| Silkscreen color | White, Black,Blue,Yellow | |||||||
| Max hole size for via filled with Blue glue aluminium | 197mil | 197mil | ||||||
| Finish hole size for via filled with resin | 4-25.4mil | 4-25.4mil | ||||||
| Max aspect ratio for via filled with resin board | 8:1 | 12:1 | ||||||
| Min width of soldermask bridge | Base copper≤0.5 oz、Immersion Tin： 7.5mil(Black), 5.5mil(Other color) , 8mil( on copper area) | |||||||
| Base copper≤0.5 oz、Finish treatment not Immersion Tin ： 5.5 mil(Black,extremity 5mil), 4mil(Other color,extremity 3.5mil) , 8mil( on copper area |
||||||||
| Base coppe 1 oz: 4mil(Green), 5mil(Other color) , 5.5mil(Black,extremity 5mil),8mil( on copper area) | ||||||||
| Base copper 1.43 oz: 4mil(Green), 5.5mil(Other color) , 6mil(Black), 8mil( on copper area) | ||||||||
| Base copper 2 oz-4 oz: 6mil, 8mil( on copper area) | ||||||||
| 15 | Surface Treatment | Lead free | Flash gold(electroplated gold)、ENIG、Hard gold、Flash gold、HASL Lead free、OSP、ENEPIG、Soft gold、Immersion silver、Immersion Tin、ENIG+OSP,ENIG+Gold finger,Flash gold(electroplated gold)+Gold finger,Immersion silver+Gold finger,Immersion Tin+Gold finge | |||||
| Leaded | Leaded HASL | |||||||
| Aspect ratio | 10:1(HASL Lead free、HASL Lead、ENIG、Immersion Tin、Immersion silver、ENEPIG);8:1(OSP) | |||||||
| Max finished size | HASL Lead 22″*39″；HASL Lead free 22″*24″；Flash gold 24″*24″；Hard gold 24″*28″；ENIG 21″*27″；Flash gold(electroplated gold) 21″*48″；Immersion Tin 16″*21″；Immersion silver 16″*18″；OSP 24″*40″； | |||||||
| Min finished size | HASL Lead 5″*6″；HASL Lead free 10″*10″；Flash gold 12″*16″；Hard gold 3″*3″；Flash gold(electroplated gold) 8″*10″；Immersion Tin 2″*4″；Immersion silver 2″*4″；OSP 2″*2″； | |||||||
| PCB thickness | HASL Lead 0.6-4.0mm；HASL Lead free 0.6-4.0mm；Flash gold 1.0-3.2mm；Hard gold 0.1-5.0mm；ENIG 0.2-7.0mm；Flash gold(electroplated gold) 0.15-5.0mm；Immersion Tin 0.4-5.0mm；Immersion silver 0.4-5.0mm；OSP 0.2-6.0mm | |||||||
| Max high to gold finger | 1.5inch | |||||||
| Min space between gold fingers | 6mil | |||||||
| Min block space to gold fingers | 7.5mil | |||||||
| 16 | V-Cutting | Panel Size | 500mm X 622 mm ( max. ) | 500mm X 800 mm ( max. ) | ||||
| Board Thickness | 0.50 mm (20mil) min. | 0.30 mm (12mil) min. | ||||||
| Remain Thickness | 1/3 board thickness | 0.40 +/-0.10mm( 16+/-4 mil ) | ||||||
| Tolerance | ±0.13 mm(5mil) | ±0.1 mm(4mil) | ||||||
| Groove Width | 0.50 mm (20mil) max. | 0.38 mm (15mil) max. | ||||||
| Groove to Groove | 20 mm (787mil) min. | 10 mm (394mil) min. | ||||||
| Groove to Trace | 0.45 mm(18mil) min. | 0.38 mm(15mil) min. | ||||||
| 17 | Slot | Slot size tol.L≥2W | PTH Slot: L：+/-0.13(5mil) W：+/-0.08(3mil) | PTH Slot: L：+/-0.10(4mil) W：+/-0.05(2mil) | ||||
| NPTH slot(mm) L+/-0.10 (4mil) W：+/-0.05(2mil) | NPTH slot(mm) L：+/-0.08 (3mil) W：+/-0.05(2mil) | |||||||
| 18 | Min Spacing from hole edge to hole edge | 0.30-1.60 (Hole Diameter) | 0.15mm(6mil) | 0.10mm(4mil) | ||||
| 1.61-6.50 (Hole Diameter) | 0.15mm(6mil) | 0.13mm(5mil) | ||||||
| 19 | Min spacing between hole edge to circuitry pattern | PTH hole: 0.20mm(8mil) | PTH hole: 0.13mm(5mil) | |||||
| NPTH hole: 0.18mm(7mil) | NPTH hole: 0.10mm(4mil) | |||||||
| 20 | Image transfer Registration tol | Circuit pattern vs.index hole | 0.10(4mil) | 0.08(3mil) | ||||
| Circuit pattern vs.2nd drill hole | 0.15(6mil) | 0.10(4mil) | ||||||
| 21 | Registration tolerance of front/back image | 0.075mm(3mil) | 0.05mm(2mil) | |||||
| 22 | Multilayers | Layer-layer misregistration | 4layers: | 0.15mm(6mil)max. | 4layers: | 0.10mm(4mil) max. | ||
| 6layers: | 0.20mm(8mil)max. | 6layers: | 0.13mm(5mil) max. | |||||
| 8layers: | 0.25mm(10mil)max. | 8layers: | 0.15mm(6mil) max. | |||||
| Min. Spacing from Hole Edge to Innerlayer Pattern | 0.225mm(9mil) | 0.15mm(6mil) | ||||||
| Min.Spacing from Outline to Innerlayer Pattern | 0.38mm(15mil) | 0.225mm(9mil) | ||||||
| Min. board thickness | 4layers:0.30mm(12mil) | 4layers:0.20mm(8mil) | ||||||
| 6layers:0.60mm(24mil) | 6layers:0.50mm(20mil) | |||||||
| 8layers:1.0mm(40mil) | 8layers:0.75mm(30mil) | |||||||
| Board thickness tolerance | 4layers:+/-0.13mm(5mil) | 4layers:+/-0.10mm(4mil) | ||||||
| 6layers:+/-0.15mm(6mil) | 6layers:+/-0.13mm(5mil) | |||||||
| 8-12 layers:+/-0.20mm (8mil) | 8-12 layers:+/-0.15mm (6mil) | |||||||
| 23 | Insulation Resistance | 10KΩ~20MΩ(typical:5MΩ) | ||||||
| 24 | Conductivity | <50Ω(typical:25Ω) | ||||||
| 25 | Test voltage | 250V | ||||||
| 26 | Impedance control | ±5ohm(＜50ohm), ±10%(≥50ohm) | ||||||
PCBTok offers flexible shipping methods for our customers, you may choose from one of the methods below.
1. DHL
DHL offers international express services in over 220 countries.
DHL partners with PCBTok and offers very competitive rates to customers of PCBTok.
It normally takes 3-7 business days for the package to be delivered around the world.
2. UPS
UPS gets the facts and figures about the world’s largest package delivery company and one of the leading global providers of specialized transportation and logistics services.
It normally takes 3-7 business days to deliver a package to most of the addresses in the world.
3. TNT
TNT has 56,000 employees in 61 countries.
It takes 4-9 business days to deliver the packages to the hands
of our customers.
4. FedEx
FedEx offers delivery solutions for customers around the world.
It takes 4-7 business days to deliver the packages to the hands
of our customers.
5. Air, Sea/Air, and Sea
If your order is of large volume with PCBTok, you can also choose
to ship via air, sea/air combined, and sea when necessary.
Please contact your sales representative for shipping solutions.
Note: if you need others, please contact your sales representative for shipping solutions.
You can use the following payment methods:
Telegraphic Transfer(TT): A telegraphic transfer (TT) is an electronic method of transferring funds utilized primarily for overseas wire transactions. It’s very convenient to transfer.
Bank/Wire transfer: To pay by wire transfer using your bank account, you need to visit your nearest bank branch with the wire transfer information. Your payment will be completed 3-5 business days after you have finished the money transfer.
Paypal: Pay easily, fast and secure with PayPal. many other credit and debit cards via PayPal.
Credit Card: You can pay with a credit card: Visa, Visa Electron, MasterCard, Maestro.
