Abstract:
In an example, a process for reversibly bonding a conformal coating to a dry film solder mask (DFSM) material is disclosed. The process includes applying a first conformal coating material to a DFSM material. The first conformal coating material includes a first functional group, and the DFSM material includes a second functional group that is different from the first functional group. The process also includes reversibly bonding the first conformal coating material to the DFSM material via a chemical reaction of the first functional group and the second functional group.
Abstract:
A method of producing a non-planar conforming circuit on a non-planar surface includes creating a first set of conforming layers. The first set of conforming layers is created by applying an oxide dielectric layer to the surface, applying a conductive material layer to the oxide dielectric layer, applying a resist layer to the conductive material layer, patterning the resist layer according to a desired circuit layout, etching the surface to remove exposed conductive material, and stripping the resist layer. The process may be repeated to form multiple layers of conforming circuits with electrical connections between layers formed by blind microvias. The resulting set of conforming layers can be sealed.
Abstract:
A method of producing a non-planar conforming circuit on a non-planar surface includes creating a first set of conforming layers. The first set of conforming layers is created by applying an oxide dielectric layer to the surface, applying a conductive material layer to the oxide dielectric layer, applying a resist layer to the conductive material layer, patterning the resist layer according to a desired circuit layout, etching the surface to remove exposed conductive material, and stripping the resist layer. The process may be repeated to form multiple layers of conforming circuits with electrical connections between layers formed by blind microvias. The resulting set of conforming layers can be sealed.
Abstract:
Systems and methods for shielding circuitry from interference with conformal coating are disclosed. Systems having conformal EMI shields according to embodiments are provided by applying insulating and conductive layers to areas of a printed circuit board (PCB). This produces systems that may be thinner and also smaller in surface area, and that may be suitable as part of electronic devices.
Abstract:
Methods and apparatuses are disclosed for fabricating a printed circuit board (PCB) having electromagnetic interference (EMI) shielding and also having reduced volume over conventional frame-and-shield approaches. Some embodiments include fabricating the PCB by mounting an integrated circuit to the PCB, outlining an area corresponding to the integrated circuit with a number of grounded vias, selectively applying an insulating layer over the PCB such that at least one of the grounded vias are exposed, and selectively applying a conductive layer over the PCB such that the conductive layer covers at least a portion of the integrated circuit and such that the conductive layer is coupled to the at least one of the grounded vias that are exposed.
Abstract:
An electronic device may be provided with printed circuits. Electrical components may be interconnected using signal paths formed from metal traces in the printed circuits. The printed circuits may include flexible printed circuits with bent configurations. The flexible printed circuits may be provided with integral bend retention structures. A bend retention structure may be formed from a polymer layer, a solder layer, a stiffener formed from metal or polymer that is attached to flexible printed circuit layers with adhesive, a conformal plastic coating that covers exposed metal traces at a bend, a metal stiffener with screw holes, a shape memory alloy, a portion of a flexible printed circuit dielectric substrate layer with a reduced elongation at yield value, or combinations of these structures. The bend retention structure maintains a bend in a bent flexible printed circuit.
Abstract:
An embodiment of a method of attaching a semiconductor die to a substrate includes placing a bottom surface of the die over a top surface of the substrate with an intervening die attach material. The method further includes contacting a top surface of the semiconductor die and the top surface of the substrate with a conformal structure that includes a non-solid, pressure transmissive material, and applying a pressure to the conformal structure. The pressure is transmitted by the non-solid, pressure transmissive material to the top surface of the semiconductor die. The method further includes, while applying the pressure, exposing the assembly to a temperature that is sufficient to cause the die attach material to sinter. Before placing the die over the substrate, conductive mechanical lock features may be formed on the top surface of the substrate, and/or on the bottom surface of the semiconductor die.
Abstract:
A blind-mate capacitive coupling interconnection between a main module enclosure one or more sub-module enclosures has coupling surfaces each with a ground portion and an aperture, an inner element provided in the aperture, spaced away from the ground portion. The coupling surfaces may be provided, for example, as traces on a printed circuit board. To accommodate a degree of mis-alignment, one of the inner elements may be provided larger than the other. Capacitive coupling between the coupling surfaces occurs when the coupling surfaces are mated together, retained in position, for example, by a mechanical fixture.
Abstract:
A method for applying a protective coating to selected portions of a substrate is disclosed. The method includes applying a mask to or forming a mask on at least one portion of the substrate that is not to be covered with the protective coating. The mask may be selectively formed by applying a flowable material to the substrate. Alternatively, the mask may be formed from a preformed film. With the mask in place, the protective coating may be applied to the substrate and the mask. A portion of the protective coating that overlies the mask may be delineated from other portions of the protective coating; for example, by cutting, weakening or removing material from the protective coating at locations at or adjacent to the perimeter of the mask. The portion of the protective coating that overlies the mask, and the mask, may then be removed from the substrate.
Abstract:
A coating system with an applicator that has an air cylinder with a needle valve. A control has a timer that provides a string of electrical pulses to a solenoid. With each pulse, the solenoid applies pressurized air to a cylinder piston, thereby opening the needle valve and permitting coating material to flow past the needle valve. The needle valve is closed for durations of time between pulses, and the coating material is ejected from a dispensing needle in response to closings of the needle valve.