... using either a projection or conformal mask to image a pattern of microvias onto the panel. The projection method makes use of a lens | PRINTED WIRING BOARDS PLANT | to project an image of the mask onto the panel, whereas the conformal process incorporates the mask onto the panel itself. In either case, laser | PRINTED WIRING BOARDS PLANT | light passing through the holes in the mask forms the microvias by ablation. Optical or mechanical positioning can also be used to scan the beam | PRINTED WIRING BOARDS PLANT | across the mask. Nonetheless, the majority of laser-formed microvias are formed sequentially using the direct method rather than en masse using masks. CO2 lasers account | PRINTED WIRING BOARDS PLANT | for about 80 percent of the lasers used for blind via and microvia formation. CO2 lasers can emit up to 225 watts of average power | PRINTED WIRING BOARDS PLANT | at a wavelength of 9.4 microns, which is a good absorption wavelength for a large number of dielectric materials such as FR-4, RCF, polyimides, PTFE, | PRINTED WIRING BOARDS PLANT | and aramids. This technology, however, requires capacity in wet chemistry and thermal oxidation for copper preparation. ...
[ Printed Wiring Boards Plant ]


... or angle on the inside edge of the barrel entrance of a connector of the cable. | CHIP ON BOARD (COB) | Technology, where | PRINTED WIRING BOARDS PLANT | a microchip (without any housing) is mounted directly on the PCB, and is connected to the pattern through wire- bonding. | CLAD | A copper | PRINTED WIRING BOARDS PLANT | object on a printed circuit board. Specifying certain text items for a board to be "in clad" means that the text should be made of | PRINTED WIRING BOARDS PLANT | copper, not silkscreen. | COMPONENT SIDE | That side of the PCB on which most of the components are mounted. | COMPOSITE BOARD A |completely | PRINTED WIRING BOARDS PLANT | laminated, multilayer PCB | COMPOUND |Die A printed circuit die that combines two or more cutting operations, such as blanking and piercing. This is usually | PRINTED WIRING BOARDS PLANT | a single action die with all operations accomplished in one stroke.   | CONDUCTIVE FOIL | A thin sheet of metal that may cover one | PRINTED WIRING BOARDS PLANT | or both sides of a base material, is intended for forming the conductive pattern. | CONDUCTOR SPACING | The distance between adjacent edges (not centerline | PRINTED WIRING BOARDS PLANT | to centerline) ...
[ Printed Wiring Boards Plant ]


... The smear is the result of a hot drill melting the epoxy resin and spreading it across the hole wall during its up and | PRINTED WIRING BOARDS PLANT | down motion. The epoxy smear causes poor and in some cases non electrical continuity to the innerlayers as well as poor adhesion of the plated | PRINTED WIRING BOARDS PLANT | copper to the hole wall. In desmear, the chemical attack is designed to remove only the surface smear of resin from the hole wall, without | PRINTED WIRING BOARDS PLANT | attacking the wall structure itself. For most needs desmearing is sufficient whilst for some military applications it is necessary to etchback 75mm for what is | PRINTED WIRING BOARDS PLANT | referred to as 3 point contact. Etchback is a stronger chemical attack than desmearing. It is designed to remove not only the smeared resin, but | PRINTED WIRING BOARDS PLANT | also additional resin from the wall structure and the remaining protruding glass fibres. There are various methods of desmearing and etchback available to multilayer manufacturers. | PRINTED WIRING BOARDS PLANT | Permanganate works on the principle of oxidising the epoxy smear. Advantages are its predictability, its ...
[ Printed Wiring Boards Plant ]