US Pat. No. 9,706,669

RIGID-FLEXIBLE CIRCUIT BOARD HAVING FLYING-TAIL STRUCTURE AND METHOD FOR MANUFACTURING SAME

GUANGZHOU FASTPRINT CIRCU...

1. A method for manufacturing a rigid-flex circuit board having a flying-tail structure, comprising the following steps:
step 1, making core plates required by respective sub-boards, the core plates required by the respective sub-boards including
at least one flexible core plate and at least one rigid core plate, and stacking and laminating the core plates to make the
sub-boards, the number of the sub-boards being equal to the number of second rigid regions, with each of the sub-boards including
a partial first rigid region, one flexible region and one second rigid region;

step 2, stacking all the sub-boards made in the step 1, and attaching polyetherimide covering films to solder-resist areas
of adjacent end surfaces of the respective second rigid regions; and

step 3, providing a PTFE spacer between adjacent flexible regions and between adjacent second rigid regions, laminating all
the sub-boards that have been processed in the step 2, the partial first rigid regions of the sub-boards being laminated together
to form a first rigid region.

US Pat. No. 10,064,284

DRILLING METHOD FOR PCBS WITH HIGH HOLE POSITION PRECISION

YIXING SILICON VALLEY ELE...

1. A drilling method for PCBs with high hole position precision, comprising:step 1, fixing a PCB on a workbench comprising:
i) mounting a bakelite plate on the workbench;
ii) drilling a location hole on the bakelite plate;
iii) inserting a pin into the location hole; and
iv) mounting a base plate and the PCB both provided with location holes aligned with the pin on the workbench sequentially;
step 2, performing pre-drill into a to-be-drilled portion of the PCB using a short-blade drilling tool, wherein the short-blade drilling tool of the step 2 has a blade length of 1 mm to 3 mm; and
step 3, performing deep drill into the to-be-drilled portion which has been processed in the step 2 using a long-blade drilling tool.

US Pat. No. 9,942,976

PREPARATION METHOD OF A BOSS-TYPE METAL-BASED SANDWICH RIGID-FLEX CIRCUIT BOARD

Guangzhou Fastprint Circu...

1. A method of preparing a boss-type metal-based sandwich rigid-flex board comprising the steps of:making a flexible sub-plate, obtained from a flexible board by inner circuit processing and windowing;
making a rigid sub-plate, obtained from a rigid board by inner circuit processing and windowing;
making a dielectric layer, obtained from a dielectric material by windowing;
making a metal core layer, including:
performing hole drilling, hole clogging and location hole punching on a metal core plate;
performing front side controlled deep milling on the metal core plate to form a metal boss on a front side of the metal core plate; and
performing back side controlled deep milling, including mounting a backing plate on the front side of the metal core plate, and performing controlled deep milling on a back side of the metal core plate to form a metal boss on the back side to complete the metal core layer;
stacking the rigid sub-plate, the flexible sub-plate, the dielectric layer and the metal core layer sequentially and performing laminating; and
performing controlled deep milling to form a second window and cover opening for a window area in the laminated structure after resistance welding the metal core layer circuit of the flexible and rigid plates, to obtain the boss-type metal-based sandwich rigid-flex board.

US Pat. No. 10,433,422

HIGH-SPEED PRINTED CIRCUIT BOARD AND DIFFERENTIAL WIRING METHOD THEREOF

Guangzhou Fastprint Circu...

1. A high-speed printed circuit board, comprising a wiring layer, a dielectric layer and a shielding layer laminated sequentially,wherein the wiring layer comprises a BGA region, a non-BGA region and two differential transmission lines disposed oppositely to each other,
each of both the differential transmission lines comprises a first differential wire located in the BGA region, a second differential wire located in the non-BGA region and a first connection wire configured to connect the first differential wire and the second differential wire,
the width of the first differential wire is less than the width of the second differential wire, the distance between the two first differential wires is less than the distance between the two second differential wires, the width of the first differential wire increases gradually from the BGA region to the non-BGA region, and the distance between the two first connection wires increases gradually from the BGA region to the non-BGA region,
wherein the width of the first differential wire and the distance between the two first differential wires satisfy a formula:

wherein, Z2 is a pre-set impedance required value of the non-BGA region, w1 is the width of the first differential wire, d1 is the distance between the two first differential wires, h is the thickness of the dielectric layer, ?r is the dielectric constant of the dielectric layer and t is the cooper thickness of the wiring layer.