Abstract:
Solder paste is applied beforehand onto through-hole upper lands (or solder) of a printed circuit board and attachment is effected by inserting solder joined to the BGA-side pads into the holes of the through-hole upper lands; solder and solder paste are then melted by heating, causing them to flow into the through-holes and to wet and spread out upon the through-hole bottom face lands, thereby effecting a soldered joint with the BGA-side pads and through-hole upper lands securely attached, and forming solder fillets. In this way, the quality of the solder joints can be ascertained by an ordinary external inspection method.
Abstract:
Apparatus and methods providing for interconnecting a component to a substrate comprising one or more via-in-pad (VIP) interconnects is presented. In one embodiment in accordance with the invention, a first interconnect material is deposited on the VIP bond pad and into at least a portion of the VIP bore adjacent the bond pad. The substrate is subjected to a reflow process to form a plug of first reflowable interconnect material having a cap and a stem. The cap conforms to the bond pad and has a predetermined thickness and a diameter larger than the diameter of the bore. The stem conforms to the diameter of the bore and extends from the cap into the bore a predetermined distance. A component interconnect is coupled to the VIP bond pad and the cap using a second reflowable interconnect material having a reflow temperature lower than that of the first interconnect material. The plug remains in a solid form and effectively blocks the migration of the second reflowable interconnect material into the VIP bore.
Abstract:
A method of cooling heat-generating electrical components during service has a heat-removing element. Heat-removing element comprises a plurality of vias therein and is fixedly attached to a tip of the electrical components, typically on opposed charged ends. Heat absorbed by the heat-removing element is then transported to a heat sink, cooperatively associated therewith, for disposal. In an electrical assemblage, a circuit board contains multiple heat generating components each being associated with a heat-removing element of the invention.
Abstract:
A method and apparatus for depositing solder paste on a printed wiring board has a stencil with a pattern of multiple apertures. The pattern aligns with a through-hole in the printed wiring board when the stencil is in physical contact with the printed wiring board. A squeegee arrangement applies solder paste through the multiple apertures in the stencil through the through-hole of the printed wiring board to the upper surface of the printed wiring board for securely mounting electronic components to the upper surface of the printed wiring board, for providing a thermal path for the heat sinks of the electronic components and for providing a low inductance electrical path to ground for the electrical components.
Abstract:
The invention is a method for attaching an electronic component (40) having Ball Grid Array contacts (36) to a circuit board contact array (31) to prevent the solder balls (36) of the Ball Grid Array from fracturing and distorting during solder reflow when the Ball grid Array contact (36) is attached to a contact (31) on a printed circuit board (30) that has a via (32) extending at least partially though the printed circuit board (30). A solder form (35) is placed over each via (32) in each contact (31) of the contact array. The electronic component (40) that has BGA contacts (36) is placed over the contact array (31) such that each ball (36) of the ball grid array of the electronic component resides on a solder form (35). The component (40) and circuit board (30) is subjected to a solder reflow process to seal the component (40) to the circuit board (30). The solder form (35) at least partially fills the via (32) preventing the BGA contact (36) from collapsing into the via (32).
Abstract:
An apparatus and a method for filling high aspect ratio holes in electronic substrates that can be advantageously used for filling holes having aspect ratios larger than 5:1 are disclosed. In the apparatus, a filler plate and a vacuum plate are used in conjunction with a connection means such that a gap is formed between the two plates to accommodate an electronic substrate equipped with high aspect ratio via holes. The filler plate is equipped with an injection slot while the vacuum plate is equipped with a vacuum slot such that when a substrate is sandwiched therein, via holes can be evacuated of air and injected with a liquid simultaneously from a bottom side and a top side of the substrate. The present invention novel apparatus and method allows the filling of via holes that have small diameters, i.e., as small as 10 nullm, and high aspect ratios, i.e., at least 5:1 to be filled with an electrically conductive material such as a solder or a conductive polymer such that vias or interconnects can be formed in electronic substrates. The present invention apparatus and method can be advantageously used in fabricating substrates for display panels by forming conductive vias and interconnects for placing a voltage potential on pixel display elements formed on the display panels.
Abstract:
Each of junctions formed between a semiconductor device and a substrate comprises metal balls of Cu etc. and compounds of Sn and the metal balls, and the metal balls are bonded together by the compounds.
Abstract:
A printed circuit board, containing thermal pads, is adhered to a rigidizer plate whereupon the entire unit can then be bent over itself to create a compact assembly which can be substantially smaller, but contain the same number of traces and electrical components, as an unbent printed circuit board of the same surface area. Further, a complete housing assembly is formed which is sealed on each edge of the rigidizer by inserting the edge into a panel with a groove. This assembly provides a secure fit that provides great stability with a relatively low weight and volume. The assembly also provides a better RF non-mechanical connection and much better thermal performance.
Abstract:
A transformer group in which a multitude of transformers are used to supply energy to a single load. The transformers are connected in series; in order to assist in providing a “flux equalizing” affect, the invention includes a flux equalizer circuit. The flux equalizer circuit provides a series of flux windings. Each flux winding is associated with a single transformer. The windings are arranged in parallel. In this manner, a balancing of the output of the transformers is obtained; the power output from each transformer is “sensed” by its associated flux winding which is “shared” with the other transformers via their own associated flux winding. Power is process then through the secondary windings, rectifiers, and output filters to a common load.
Abstract:
There is provided a composite wiring board that occupies a small space and is low in price and a manufacturing method thereof; the composite wiring board comprises at least two rigid wiring boards on end faces of which connection portions are formed, in which each of the rigid wiring boards is arranged so that each of the connection portions is situated on a plane and each of corresponding connection portions is connected with each other in the plane.