Stack-up for FPC
The following is the usual FPC stackup information. If you need custom FPC stackup, please make note and we will manufacture according to your requirement.
Polyimide (PI) is the most commonly used thermal curing insulating material in flexible circuit processing. The thickness range of the material is generally 12.5μm (0.5mil) and 125μm (5mil). Divided into with glue and without glue, the DK with glue is 3.5, and the DK without glue is 3.3.
FPC Stackup of PET (Transparent)
Thickness
- 0.11mm (Single Layer)
- 0.2mm (2 Layers)
- 0.23mm (2 Layers)
| Top coverlay | PET | 25um |
| Adhesive | 25um | |
| Top copper layer | Copper | 18um (Finished copper thickness 18um) |
| Adhesive | 20um | |
| PI | 25um Dielectric constant 3.3~3.5 (The DK value is not absolute and will vary depending on the base material’s models and thickness.) | |
| Total thickness | 113um |
FPC Stackup of thin FPC
Thickness
- 0.025mm (Single Layer)
- 0.05mm (Single Layer)
- 0.08mm (2 Layers)
| Top copper layer | Copper | 9um |
| PI | 12.5um Dielectric constant 3.3~3.5 (The DK value is not absolute and will vary depending on the base material’s models and thickness.) | |
| Total thickness | 21.5um |
Single Layer FPC Stackup
Thickness
- 0.08mm
- 0.1mm
- 0.12mm
- 0.13mm
- 0.15mm
- 0.16mm
- 0.17mm
- 0.18mm
- 0.2mm
| Top coverlay (Yellow coverlay / Black coverlay) | PI | 12.5um |
| Adhesive | 15um | |
| Top copper layer | Copper | 18um (Finished copper thickness 18um) |
| Adhesive | 13um | |
| PI | 25um Dielectric constant 3.3~3.5 (The DK value is not absolute and will vary depending on the base material’s models and thickness.) | |
| Total thickness | 83.5um |
2 Layers FPC Stackup
Thickness
- 0.1mm
- 0.12mm
- 0.13mm
- 0.15mm
- 0.16mm
- 0.17mm
- 0.18mm
- 0.2mm
- 0.22mm
- 0.23mm
- 0.24mm
- 0.25mm
- 0.26mm
- 0.27mm
- 0.29mm
- 0.3mm
- 0.34mm
- 0.35mm
- 0.38mm
| Top coverlay (Yellow coverlay / Black coverlay) | PI | 12.5um |
| Adhesive | 15um | |
| Top copper layer | Copper | 12um (Finished copper thickness 18um) |
| Adhesive | 0um | |
| PI | 25um Dielectric constant 3.3~3.5 (The DK value is not absolute and will vary depending on the base material’s models and thickness.) | |
| Adhesive | 0um | |
| Bottom copper layer | Copper | 12um (Finished copper thickness 18um) |
| Bottom coverlay (Yellow coverlay / Black coverlay) | Adhesive | 15um |
| PI | 12.5um | |
| Total thickness | 104um |
4 Layers FPC Stackup
Thickness
- 0.2mm
- 0.22mm
- 0.23mm
- 0.25mm
- 0.26mm
- 0.27mm
- 0.3mm
- 0.33mm
| Top coverlay (Yellow coverlay / Black coverlay) | PI | 12.5um |
| Adhesive | 15um | |
| Top copper layer | Copper | 12um (Finished copper thickness 18um) |
| Adhesive | 0um | |
| PI | 25um Dielectric constant 3.3~3.5 (The DK value is not absolute and will vary depending on the base material’s models and thickness.) | |
| Pure gum | 13um | |
| Inner 2 layer | Copper | 12um |
| Adhesive | 0um | |
| PI | 25um Dielectric constant 3.3~3.5 (The DK value is not absolute and will vary depending on the base material’s models and thickness.) | |
| Adhesive | 0um | |
| Inner 3 layer | Copper | 12um |
| Pure gum | 13um | |
| PI | 25um Dielectric constant 3.3~3.5 (The DK value is not absolute and will vary depending on the base material’s models and thickness.) | |
| Adhesive | 0um | |
| Bottom copper layer | Copper | 12um (Finished copper thickness 18um) |
| Bottom coverlay (Yellow coverlay / Black coverlay) | Adhesive | 15um |
| PI | 12.5um | |
| Total thickness | 204um |
4 Layers Rigid-Flex Stackup
Thickness
- 1.6mm
| Rigid part | Flex part | |||
| Top soldermask layer | 20um | |||
| Rigid-top copper layer | Copper | 18um (Finished copper thickness 35um) | ||
| FR4 | 680um | PI | 12.5um | |
| Pure gum | 13um | Adhesive | 15um | |
| Flex-copper 2 layer | Copper | 18um | Copper | 18um |
| Adhesive | 13um | Adhesive | 13um | |
| PI | 25um dielectric constant 3.3~3.5 (The DK value is not absolute and will vary depending on the base material’s models and thickness.) | PI | 25um dielectric constant 3.3~3.5 (The DK value is not absolute and will vary depending on the base material’s models and thickness.) | |
| Adhesive | 13um | Adhesive | 13um | |
| Flex-copper 3 layer | Copper | 18um | Copper | 18um |
| Pure gum | 13um | Adhesive | 15um | |
| FR4 | 680um | PI | 12.5um | |
| Rigid-bottom copper layer | Copper | 18um (Finished copper thickness 35um) | ||
| Bottom soldermask layer | 20um | |||
| Total thickness | 1549um | FPC thickness | 142um | |
6 Layers FPC Stackup
Thickness
- 0.3mm
- 0.33mm
- 0.34mm
- 0.37mm
- 0.38mm
- 0.42mm
| Top coverlay (Yellow coverlay / Black coverlay) | PI | 12.5um |
| Adhesive | 15um | |
| Top copper layer | Copper | 12um (Finished copper thickness 18um) |
| Adhesive | 0um | |
| PI | 25um Dielectric constant 3.3~3.5 (The DK value is not absolute and will vary depending on the base material’s models and thickness.) | |
| Pure gum | 13um | |
| Inner 2 layer | Copper | 12um |
| Adhesive | 0um | |
| PI | 25um Dielectric constant 3.3~3.5 (The DK value is not absolute and will vary depending on the base material’s models and thickness.) | |
| Adhesive | 0um | |
| Inner 3 layer | Copper | 12um |
| Pure gum | 13um | |
| Coverlay | 27.5um | |
| Inner 4 layer | Copper | 12um |
| Adhesive | 0um | |
| PI | 25um Dielectric constant 3.3~3.5 (The DK value is not absolute and will vary depending on the base material’s models and thickness.) | |
| Adhesive | 0um | |
| Inner 5 layer | Copper | 12um |
| Pure gum | 13um | |
| PI | 25um Dielectric constant 3.3~3.5 (The DK value is not absolute and will vary depending on the base material’s models and thickness.) | |
| Adhesive | 0um | |
| Bottom copper layer | Copper | 12um (Finished copper thickness 18um) |
| Bottom coverlay (Yellow coverlay / Black coverlay) | Adhesive | 15um |
| PI | 12.5um | |
| Total thickness | 293.5um |
8-16 Layers FPC Stackup
Thickness
- 0.45mm (8 Layers)
- 0.57mm (10 Layers)
- 0.68mm (12 Layers)
- 0.8mm (14 Layers)
- 0.91mm (16 Layers)
| Top coverlay | PI | 12.5um |
| Adhesive | 12.5um | |
| Top copper layer | Copper | 18um |
| PI | 25um Dielectric constant 3.3~3.5 (The DK value is not absolute and will vary depending on the base material’s models and thickness.) | |
| Adhesive | 20um | |
| Inner 2 layer | Copper | 12um |
| PI | 25um Dielectric constant 3.3~3.5 (The DK value is not absolute and will vary depending on the base material’s models and thickness.) | |
| Adhesive | 20um | |
| Inner 3 layer | Copper | 12um |
| PI | 25um Dielectric constant 3.3~3.5 (The DK value is not absolute and will vary depending on the base material’s models and thickness.) | |
| Adhesive | 20um | |
| Inner 4 layer | Copper | 12um |
| PI | 25um Dielectric constant 3.3~3.5 (The DK value is not absolute and will vary depending on the base material’s models and thickness.) | |
| Inner 5 layer | Copper | 12um |
| Adhesive | 20um | |
| PI | 25um Dielectric constant 3.3~3.5 (The DK value is not absolute and will vary depending on the base material’s models and thickness.) | |
| Inner 6 layer | Copper | 12um |
| Adhesive | 20um | |
| PI | 25um Dielectric constant 3.3~3.5 (The DK value is not absolute and will vary depending on the base material’s models and thickness.) | |
| Inner 7 layer | Copper | 12um |
| Adhesive | 20um | |
| PI | 25um Dielectric constant 3.3~3.5 (The DK value is not absolute and will vary depending on the base material’s models and thickness.) | |
| Bottom copper layer | Copper | 18um |
| Bottom coverlay | Adhesive | 12.5um |
| PI | 12.5um | |
| Total thickness | 453um |
Stackup of FPC with Airgap
Thickness
- 0.16mm (2 Layers)
- 0.24mm (4 Layers)
- 0.37mm (6 Layers)
- 0.5mm (8 Layers)
