Abstract:
A printed circuit board, especially for a computer keypad, and method for avoiding electromagnetic interference include conductive signal traces positioned on a surface of one of a nonconductive layer that is other than the outward facing surface of an outer nonconductive layer, and vertical interconnect accesses extending through the outer nonconductive layer and connecting the signal traces to the outward facing surface of the outer nonconductive layer, wherein each vertical interconnect access includes a conductive portion on the outward facing surface of the outer nonconductive layer, and the conductive portion has an area no greater than 1/10 the area of the asociated signal trace. Keys selectively connect pairs of vertical interconnect accesses.
Abstract:
A printed circuit board comprises a circuit substrate, an electrically conductive cloth structure, and a shielding structure. The circuit substrate comprises a base layer, a grounded circuit layer, and a connecting pad formed on the grounded circuit layer. The cloth structure comprises an anisotropic conductive adhesive connected to the connecting pad, an insulating layer, and a metallic deposition layer arranged between the anisotropic conductive adhesive and the insulating layer. The shielding structure comprises a shielding metal layer, an adhesive matrix, and a number of electrically conductive particles electrically connected to the shielding metal layer. The insulating layer defines a number of through holes corresponding to the particles, the particles is arranged in the through holes respectively and electrically connected the metallic deposition layer and the shielding metal layer. A method for manufacturing the above PCB is also provided.
Abstract:
According to one exemplary embodiment, a circuit board for reducing dielectric loss, conductor loss, and insertion loss includes a pair of transmission lines. The pair of transmission lines has sufficient thickness to cause substantial broadside electromagnetic coupling between the pair of transmission lines, where the pair of transmission lines is sufficiently separated from a ground plane of the circuit board so as to cause negligible electromagnetic coupling to the ground plane relative to the substantial broadside electromagnetic coupling. The pair of transmission lines thereby reduce dielectric loss, conductor loss, and insertion loss for signals traversing through the transmission line pair. The pair of transmission lines can be separated from the ground plane by, for example, at least 50.0 mils.
Abstract:
In a method for manufacturing multilayer PCBs having n circuit layers, a double-sided flexible substrate strip is provided. The strip comprises a number of PCB units, each comprising m segments, wherein m=n/2 if n represents an even integer, and m=(n+1)/2 if n represents an odd integer. Each segment includes two foil portions. In a reel to reel process, the strip is treated to form n−2 foil portions of each PCB unit into traces, further remove one foil portion if n represents an odd integer. The other two foil portions are left untreated. Then the strip is cut to separate the PCB units from each other. The PCB unit is folded in such a manner that the traces are arranged between the other two foil portions. The folded PCB unit is laminated to form a multilayer substrate and traces are formed in the two foil portions.
Abstract:
The embodiment of the invention is about a novel via structure which can be incorporated into printed circuit boards, integrated circuit packages, and integrated circuits in order to reduce crosstalk, to improve signal integrity and to achieve EM emission compliance. A 4-layer (2 signal layers and 2 power layers or 2 signal layers and 2 ground layers) circuit board assembly was used for demonstrating the effect of the novel via structure. The same concept can be applied to any multi-layer circuit board. Layers that have an electrical property can be added above, under, or within the basic 4-layer circuit board to achieve a multi-layer circuit board. For 2-layer and 3-layer circuit boards, a deformed version of the proposed via structure based upon the same concept will be needed for a coplanar waveguide configuration.
Abstract:
A flexible printed circuit board wherein the insulative substrate 34 having a plurality of conductive layers 36b covered with a protective layer 38 is encircled by a mesh-cloth member 32.
Abstract:
The present disclosure provides a printed circuit board (PCB) comprising a first ground layer extended in one direction a first dielectric layer laminated on the first ground layer and extended in the same direction as that of the first ground layer; a signal transmission line laminated on the first dielectric layer and extended in the same direction as that of the first dielectric layer; and a plurality of first ground patterns formed by etching a surface of the first ground layer in an axial direction thereof at a predetermined interval in a line, wherein the plurality of first ground patterns expose the first dielectric layer.
Abstract:
The high-frequency wiring board of the present invention includes: first coplanar lines provided with a first signal line and a first planar ground pattern formed on the same wiring layer as the first signal line; second coplanar lines provided with a second signal line formed on a different wiring layer than the first signal line and a second planar ground pattern formed on the same wiring layer as the second signal line; and a first ground pattern formed on the same wiring layer as the first coplanar lines. The first coplanar lines and the second coplanar lines are connected. At least the first ground pattern and the first planar ground pattern are separated in a region following the second signal line from the connection of the first signal line and the second signal line.
Abstract:
A multilayer wiring board 100 comprises a first wiring region 101 where wirings 103a and insulating layers 104a and 104b are alternately laminated, and a second wiring region 102 where a thickness H2 of an insulating layer 104 is twice or more a thickness H1 of the insulating layer in the first wiring region 101 and a width W2 of a wiring 103b is twice or more a width W1 of the wiring in the first wiring region 101. The first wiring region 101 and the second wiring region 102 are integrally formed on the same board.
Abstract:
Impedance control, and the uniformity of electrical and mechanical characteristics in electronic packaging are becoming more important as chip and bus speeds increase and manufacturing processes evolve. Current state of the art design and manufacture processes inherently introduce physical dielectric thickness variations into PCB cross sections. These thickness variations between the ground reference plane(s) and the signal layer(s) inject undesirable characteristic impedance variations and undesirable mechanical variations in thickness and surface topology. Therefore a process of generating equalization data and a design structure for multilayer electronic structures is presented.