Abstract:
The present invention concerns a process for the deposition of a solder-through polymer coating on an uncoated printed circuit board which comprises the use of an average low power and low pressure plasma polymerisation in a polymerisation chamber of an organosilane precursor monomer which is introduced into said polymerisation chamber by means of a carrier gas, said organosilane being of the Formula Y1-X-Y2 (I) or -[Si(CH3)2-X-]n- (II), wherein : X is O or NH; Y1 is - Si(Y3)(Y4)Y5; Y2 is Si(Y3')(Y4')Y5'; Y3, Y4, Y5, Υ3', Υ4', and Y5' are each independently H or an alkyl group of up to 10 carbon atoms; the monomer of formula (II) is cyclic wherein n is 2 to 10, and wherein at most one of Y3, Y4 and Y5 is hydrogen, at most one of Υ3', Y4' and Y5' is hydrogen and the total number of carbon atoms is not more than 20.
Abstract:
The present invention relates to an electrical assembly which has a conformal coating, wherein said conformal coating is obtainable by a method which comprises plasma polymerization of a compound of formula (I) and deposition of the resulting polymer and plasma polymerization of a fluorohydrocarbon and deposition of the resulting polymer: (I) wherein: R 1 represents C 1 -C 3 alkyl or C 2 -C 3 alkenyl; R 2 represents hydrogen, C 1 -C 3 alkyl or C 2 -C 3 alkenyl; R 3 represents hydrogen, C 1 -C 3 alkyl or C 2 -C 3 alkenyl; R 4 represents hydrogen, C 1 -C 3 alkyl or C 2 -C 3 alkenyl; R 5 represents hydrogen, C 1 -C 3 alkyl or C 2 -C 3 alkenyl;; and R 6 represents hydrogen, C 1 -C 3 alkyl or C 2 -C 3 alkenyl.
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 mobile wireless communications device may include a portable housing, a printed circuit board (PCB) carried by the portable housing, and at least one electronic component carried by PCB and extending upwardly therefrom. The mobile wireless communications device may also include a conformable, shape-retaining film being vacuum formed onto the at least one electronic component and may include a peripheral edge secured to the PCB and a body portion conforming to the at least one electronic component. The conformable, shape-retaining film may operate similar to a heat sink, for example, to facilitate removal of heat from a processor, for example. The processor may generate an increased amount of heat compared to other electronic components. Moreover, the conformable, shape-retaining film may also provide increased RF shielding of some electronic components from other circuitry, for example, the wireless transceiver and the antenna of the device.
Abstract:
An automatic vertical dip coater provides for simultaneous ultraviolet curing of a conformal coating on both sides of a circuit board (18). A circuit board (18) to be coated on both sides with a conformal coating is placed on a tool (12) which is advanced towards a dip-coating tank (20) containing a ultraviolet radiation curable conformal coating (48) so that both sides of the circuit board (18) are immersed in said conformal coating to a predetermined position. The coating is then dried by means of opposed ultraviolet lamps (34,36).
Abstract:
La présente invention a pour objet l'encapsulation de circuits électroniques, encapsulation qui soit hermétique c'est-à-dire qui ne laisse pas passer les gaz et, tout particulièrement, pas la vapeur d'eau. Selon l'invention, cette encapsulation est réalisée par une couche (13) dont la composition est variable; cette couche est constituée d'un matériau électriquement isolant du côté du circuit imprimé, dont la composition varie avec l'épaisseur de la couche entre matériau organique et matériau minéral, le matériau minéral formant une pellicule hermétique.
Abstract:
Spray coating, particularly flat spray coating of circuit boards. Applicant's method of discrete conformal coating eliminates "railroading" at the edges of the flat spray web and assures precise control of the amount of coating material placed on the circuit board surface, as well as on the varying and complex circuit board components. The method includes pressurizing the coating; longitudinally advancing a surface to be coated, such as a circuit board, beneath the coating, while simultaneously feeding the coating onto the advancing surface as a plural series of aligned droplets extending transversely across the advancing surface. The feeding of coating is triggered "ON/OFF" so as to define longitudinally the series of droplets feeding onto the advancing surface.
Abstract:
Apparatus and methods for producing intermittent, discrete patterns of coating material onto discrete irregular substrate areas, such as electronic circuit boards (10), where the patterns have sharp, square leading and trailing edges (13,16), as well as side edges (14,15). A slot nozzle die (32) has elongated air slots (61,62) along the slot extrusion opening (40). In the operation of the apparatus, the air flow is initiated from both air slots (61,62) prior to the initiation of the coating material flow. Also, the air flow is continued beyond that point in time, when the coating material flow ceases. The delays between the operations of the air flow and the hot melt flow are on the order of micro seconds. Alternatively, the lead and lag air start and stop times on each side of the film of coating material are different to control the exact disposition of the square cut-on and square cut-off coating edge on the circuit board. The air flow carries the film coating material to the circuit board (10) for deposition in discrete areas thereon. The sharp cut-on and cut-off accommodate multiple discrete area coating or multiple automated circuit board coating.