Definition: Blind FPC refers to an isolated hole made on a flexible printed circuit board by laser or mechanical means, which is not connected to the board surface or the board edge. These holes end within a certain depth and do not penetrate the entire thickness of the plate.

Limited drilling depth: The design of blind holes allows them to only end within a certain depth, effectively saving space while avoiding the impact of drilling on other layers.
Inter layer connection: Blind holes can achieve electrical connections between different layers, reducing the complexity of circuits required in traditional multilayer boards and improving signal integrity and transmission efficiency.
High strength and stability: Blind holes can improve the mechanical strength of the circuit board during the manufacturing process, making it suitable for use in high-temperature environments, ensuring the stability and reliability of the product.

Structure: Blind hole FPC is usually composed of multiple layers, including conductive layers, insulation layers, and cover films. Blind holes are located between these layers, serving to connect conductive lines between different layers.

Conductive layer: Made of high conductivity copper foil material to ensure stable signal transmission.
Insulation layer: Insulation materials with excellent dielectric and heat resistance properties, such as polyimide (PI) or polyester (PET), are used to protect conductive lines and prevent signal interference.
Cover film: used to protect circuits and components, preventing damage to circuit boards from external environments.

The manufacturing process of blind hole FPC is relatively complex, mainly including the following steps:
Inner layer circuit fabrication: Inner layer circuits are fabricated on the substrate, and predetermined circuit patterns are formed through processes such as photolithography and etching.
Blind hole drilling: Use high-precision drilling equipment to drill blind holes at the desired location. This step requires precise control of the depth and position of the borehole to ensure that the blind hole can be correctly connected to the specified inner circuit.
De drilling and metalization: After drilling, there will be some impurities such as drill cuttings and oil stains remaining on the hole wall, which need to be treated for de drilling. Afterwards, metallization treatments such as electroless copper plating and electroplated copper are carried out to form a conductive layer on the walls of blind holes.
Layering and Outer Circuit Manufacturing: Layering multiple layers of materials together and creating conductive circuits on the outer layer. This step requires ensuring tight bonding between layers and stable electrical performance.
Surface treatment and cover film bonding: Apply anti-oxidation treatment to the surface of the circuit board and bond the cover film at designated locations to protect the circuit.
Molding and Inspection: Cutting, bending, and other molding processes are carried out on circuit boards, and strict quality inspections are conducted to ensure that they meet design and usage standards.

Blind hole FPC is widely used in various fields due to its unique characteristics and advantages, especially in products that require high signal transmission speed and quality. For example:
Communication equipment: In communication devices such as smartphones and tablets, blind hole FPC is used to connect key components such as antennas and RF modules, achieving high-speed and stable signal transmission.
Computers and peripherals: Blind FPC is used to connect high-speed signal transmission components such as motherboards and graphics cards in laptops, printers, and other computers and peripherals.
Automotive electronics: In automotive electronic components such as display screens and sensors, blind hole FPC's high temperature resistance and vibration resistance make it suitable for the complex working environment inside the car.
Medical equipment: In medical devices such as monitors and endoscopes, the flexibility and high reliability of blind hole FPC enable it to adapt to various complex shapes and space limitations.

If pursuing cost-effective FPC manufacturing services, choosing a Chinese manufacturer is the best choice. As a manufacturing powerhouse, China has abundant resources, cheap labor, and a large number of technical personnel. We recommend Haibo, a Chinese FPC assembly service provider with over 10 years of experience, who has performed outstandingly in various aspects

Efficient and reasonable quotation:There is an efficient quotation process to assist you in making decisions, providing reasonable prices and highly competitive quotes in China.
High quality and reliable products:Produce high standard printed circuit boards, manufacture and test according to specifications, international standards, and internal controls, and conduct pre production inspections to ensure robust processes.
Quick and on-time delivery:The assembly equipment is in good condition, with high productivity, minimal downtime, short delivery time, and also provides urgent services.
Timely and effective response:Always respond to customer needs, provide accurate information, answer questions through multiple channels, and offer one-stop services.
Strong technical strength:China's FPC manufacturing technology is leading, and Haibo has a complete SMT solution that covers assembly, inspection, and other capabilities. It also provides prototype production and customization services.