A Flex PCB will have flexibility over the entire circuit. A Rigid-Flex circuit will consist of one or more rigid PCBs each connected by a Flex. Designers will often consider this technology when the have a limited space to house the circuits. Flex and Rigid-Flex can fit a product rather than the size of the product having to be designed to fit the circuits.
The main advantages include:
Engineers will often call a Flex circuit different things. Terms such as Flexible Printed Circuits, Flex PCBs, Flex Circuits, FPC (Flexible Printed Circuit) are used. The copper conductor circuit is encapsulated by a thin insulating Polyimide film. One of the advantages of Polyimides is they have high temperature resistance which can aid assembly and the final product environment. Flex circuits can be constructed as single sided, double sided or multi-layered and manufactured as a connector or designed for use with components. Rigid stiffeners can be included.
| Item | Sample (Order Area <3m2) | Batch (Order Area ≥3m2) |
|---|---|---|
| Main Materials | ||
| Insulation Layer | CVL, Ink | CVL, Ink |
| Colour of coverlay | Yellow, Black, White | Yellow, Black, White |
| Colour of ink | Yellow, Green | Yellow, Green |
| Dielectric layer | 0.012mm-0.1mm | 0.025-0.1mm |
| Additional Materials | ||
| FR-4 Stiffener | 0.1-3.2mm | 0.1-3.2mm |
| PI Stiffener | 0.075-0.225mm | 0.075-0.225mm |
| Steel reinforcement | 0.2-0.6mm | 0.2-0.4mm |
| Other Materials | 3M tape, snap dome, electromagnetic shielding, lid-off film, micro-sticking film | 3M tape, snap dome, electromagnetic shielding, lid-off film, micro-sticking film |
| Structure | 1+n+1 ; 1+1+n+1+1 ; 2+n+2 (needs review) | 1+n+1 ; 1+1+n+1+1 ; 2+n+2 (needs review) |
| F+R (needs review), cu+F+cu (needs review), R+F+R+F+R (needs review), R+F+R | R+F+R | |
| Layers | ≤14L | ≤8L |
| Board Thickness | 0.06-0.35mm | 0.1-0.35mm |
| Tolerance of Board Thickness | Flexible Area 0.03mm;PI Stiffener Area 0.05mm;FR-4 Stiffener Area 0.1mm | Flexible Area 0.03mm;PI Stiffener Area 0.05mm;FR-4 Stiffener Area 0.1mm |
| Min single unit Size | PCB Size: 5mm*15mm-310mm*510mm | PCB Size:5mm*15mm-310mm*510mm |
| Copper Thickness | Outer layer 2oz, Inner layer 2oz | Outer layer 1oz, Inner layer 1oz |
| Outline | Breakaway Tab, Single PCB | Breakaway Tab, Single PCB |
| Surface Treatment | HASL, HASL lead free (single-side FPC only), ENIG, OSP (no-stiffener only) | ENIG |
A Rigid-Flex PCB consists of a Flex board connected to a Rigid PCB. They are hybrid circuits and can be a Flex with an FR4 stiffener or two or more separate rigid FR4 boards connected with Flex circuits.
These circuits offer the best of both flexible circuits and rigid boards combined in one PCB.
Rigid-Flex boards are often considered by designers to be the ultimate solution for making use of available packaging space. They will have lower component and assembly costs so can reduce the overall cost of the final product.
| Item | Sample (Order Area <3m2) | Batch (Order Area ≥3m2) | |
|---|---|---|---|
| Material | |||
| Tg170 | S1000-2M, IT180A | S1000-2M, IT180A | |
| Hi-Tg FR4 (halogen-free) | S1165 | S1165 | |
| Hi-speed material: | needs review | needs review | |
| Structure | 1+n+1 ; 1+1+n+1+1 ; 2+n+2 (needs review) | ||
| F+R (needs review), cu+F+cu (needs review), R+F+R+F+R (needs review), R+F+R | R+F+R | ||
| Layer | ≤18L | ≤16L | |
| Board Thickness | 0.5-3.2mm | 0.5-3.2mm | |
| Copper Thickness | Outer layer 2oz, Inner layer 2oz | Outer layer 2oz ， Inner layer 2oz | |
| Outline | |||
| Processes | Rigid Area | Single PCB; V-Cut; Breakaway Tab; Breakaway Tab+Stamp Holes; Breakaway Tab+V-Cut; Breakaway Tab+V-Cut+Stamp Holes | Single PCB;V-Cut; Breakaway Tab; Breakaway Tab+Stamp Holes; Breakaway Tab+V-Cut; Breakaway Tab+V-Cut+Stamp Holes |
| Flexible Area | Breakaway Tab, Single PCB | Breakaway Tab, Single PCB | |
| Tolerance of Size | Rigid Area | 0.1mm | 0.15mm |
| Flexible Area | 0.05mm | 0.1mm | |
| Drilling | |||
| Drill bit(min) for mechanical drill | 0.15(Board Thk≤1.2mm)-6.2mm | 0.2-6.2mm | |
| The gap between hole wall for different webs (CAF): | IPC standard | 12mil | 12mil |
| Military standard | 16mil | 16mil | |
| Hole to trace distance (after compensation) for one lamination | 4L-5.5mil; 6L-6.5mil; 8L-7mil; 10L-8mil; 12-18L-10mil | 4L-6mil; 6L-7mil; 8L-8mil; 10L-10mil; 12-18L-12mil | |
| Surface treatment | HASL, HASL lead free, ENIG, Immersion Tin (needs review), Immersion Silver (needs review), OSP, HASL+Gold Finger (needs review), ENIG+Gold Finger, ENEPIG OSP+Gold, Finger (needs review), ENIG+OSP (needs review) | HASL, HASL lead free, ENIG, Immersion Tin (needs review), Immersion Silver (needs review), OSP, HASL+Gold Finger(needs review), ENIG+Gold Finger, ENEPIG, OSP+Gold, Finger (needs review), ENIG+OSP (needs review) | |
| Solder Mask | Colour | Green, Yellow, Black, Blue, Red, White, Matt Green, Matt Black | Green, Yellow, Black, Blue, Red, White, Matt Green, Matt Black |
| Silkscreen | Colour | White, Yellow, Black | White, Yellow, Black |
TCL (Europe) Elektronika Kft.
120-122 Rona Street,
1149 Budapest,
Hungary
+36-14-683970
sales@tclelektronika.com
TCL Elektronika can manufacture PCBs ranging from single-sided to complex boards in excess of 40x layers. Our in-house CAM engineering resource allows us to rapidly check, panelise and commercially optimise a fast turnaround prototype as well as small volumes.