The present invention relates to a method for electroless deposition of a bendable nickel-phosphorous alloy layer onto flexible substrates such as flexible printed circuit boards and the like. The nickel-phosphorous alloy layer is deposited from an aqueous plating bath comprising nickel ions, hypophosphite ions, at least one complexing agent and a grain refining additive selected from the group consisting of formaldehyde and formaldehyde precursors. The nickel-phosphorous alloy layers obtained have a columnar microstructure oriented perpendicular to the flexible substrate and are sufficiently bendable.

Method for electroless nickel-phosphorous alloy deposition onto flexible substrates

Embodiments of the present invention provide a flexible base substrate and a fabrication method thereof. The flexible base substrate comprises: a first flexible film layer, having an upper surface and a lower surface opposite to each other, wherein a plurality of concave parts are arranged on the lower surface of the first flexible film layer.

Flexible Base Substrate and Fabrication Method Thereof

The present invention provides a multi-layer flexible circuit board built-in golden finger exposure process which comprises the steps of inner layer single side circuit production, upper outer layer copper foil inner layer golden finger etching and windowing, PI surface hot pressing glue pasting and lamination and positioning hole making, inner layer golden finger stamping and windowing, upper and lower layer alignment and hot pressing, positioning hole making and numerical control drilling, plasma processing and smear removal, anti-plating tape pasting at a window, copper deposition and copper plating, anti-plating tape tearing, outer layer circuit making, front and back side covering film pasting, hot pressing and baking, electroless nickel and immersion gold, and subsequent conventional process. According to the process of the invention, the built-in golden finger of a multi-layer flexible circuit board is exposed, the insertion effect same with that of an outer layer golden finger is achieved, the wire layout becomes easy and neat, the number of layers can be reduced, the cost is reduced, and the anti-interference ability of the circuit is improved.

Multi-layer board flexible circuit board built-in golden finger exposure process

The invention discloses a multi-chip-embedded flexible printed circuit board and a manufacturing method thereof. The flexible printed circuit board comprises a double-face copper foil no-adhesive base material. The double-face copper foil no-adhesive base material comprises a first copper foil and a second copper foil which are fixed mutually, wherein the first copper foil and the second copper foil are respectively provided with a circuit pattern formed thereon, and the circuit patterns on the first copper foil and the second copper foil are connected through metalized micro-holes; and the first copper foil is at least equipped with two chips. At least a part of the double-face copper foil no-adhesive base material bends and is subjected to glue-seal fixation so as to enable a part of the chips to be piled up on the other part of chips. The manufacturing method is a method used for manufacturing the multi-chip-embedded flexible printed circuit board above. The multi-chip-embedded flexible printed circuit board and the manufacturing method thereof have the beneficial effect of reducing product size.

Multi-chip-embedded flexible printed circuit board and manufacturing method thereof

The invention discloses a method of configuring a FPC (Flexible Printed Circuit) gold finger pressing pin. The method comprises steps: a gold finger layer is formed on a substrate; a shielding layer for shielding part of a gold finger pattern is arranged on the gold finger layer so as to enable a region for forming the FPC gold finger pressing pin to be exposed; and the region, corresponding to the FPC gold finger pressing pin, on the gold finger layer is coated with an enhanced film for forming the FPC gold finger pressing pin. The shape of the gold finger pressure welding region does not need to be considered, one shielding layer only needs to be set to shield the gold finger pressure welding part, the FPC gold finger pressing pin can be formed at one time, and an overlapping phenomenon caused by different shielding layers formed during the technological manufacturing process can also be avoided.

Method of configuring FPC (Flexible Printed Circuit) gold finger pressing pin

The invention relates to a method for manufacturing a flexible carrying board of which the chip is directly packaged on a flexible printed circuit carrying board (COF), in particular to a method for manufacturing a golden finger of a soldering-pan of a flexible carrying board. The COF packaged flexible carrying board is made of a glueless flexible substrate; a basement membrane of the substrate is made of a polyimide material and has the thickness between 12 and 25 micrometers; and a conductor layer is made of copper, and has the thickness between 9 and 36 micrometers. The method for manufacturing the golden finger of the soldering-pan of the flexible carrying board comprises low-stress electroless nickel plating & gold immersion technology; a raw material is nickel sulfate and a reducing agent is sodium hypophosphite; and in order to reduce the stress of a nickel layer, an additive for reducing the stress is added. The low-stress additive is one or more of benzene sulfonic acid sodium salt, coumarin, formaldehyde, aldehyde and naphthalene disulfonic acid, and the concentration is 0.01 to 0.2 mol/liter. The operating temperature of the low-stress electroless nickel plating is between 80 and 85 DEG C and the pH value is between 4.8 and 5.2.

Ping Liu

Papers

Method for manufacturing golden finger of soldering-pan of flexible package carrying board