Abstract:
The invention relates to the manufacture of printed circuit boards having enhanced etch uniformity and resolution. The process eliminates the need for a black oxide treatment to improve adhesion and improves the ability to optically inspect the printed circuit boards. The process is performed by conducting steps (a) and (b) in either order: a) depositing a first surface of an electrically conductive layer onto a substrate, which electrically conductive layer has a roughened second surface opposite to the first surface; b) depositing a thin metal layer onto the roughened second surface of the electrically conductive layer, which metal layer comprises a material having a different etch resistance property than that of the electrically conductive layer. Thereafter one deposits a photoresist onto the metal layer; imagewise exposes and develops the photoresist, thereby revealing underlying portions of the metal layer. The one removes the revealed underlying portions of the metal layer, thereby revealing underlying portions of the conductive layer and removes the revealed underlying portions of the conductive layer, to thereby produce a printed circuit layer.
Abstract:
A process for the etching of multiple layers of at least two different metals, for instance a first layer of copper and a second layer of aluminium, comprises: forming a resist (10) pattern over a first layer (18) of metal, said resist pattern having a pattern of openings (14) therein, applying a first etch solution onto said resist pattern so that at least some etch solution contacts exposed areas of the first layer of metal, etching away the majority of the depth of the first metal in exposed areas of metal in the first layer of metal, applying a second etch solution onto the resist pattern the second etch solution having a rate of etch towards the first metal as compared to the first etch solution that is at least 20% less than the millimeter/minute rate of etch of the first etch solution at the same etch solution temperature, removing the second etch solution from said resist pattern after at least the first metal layer has been etched sufficiently to expose areas of a second metal layer (6) underlying the first metal layer (8) by forming an etched first metal layer, and applying a third etch solution to said etched first metal layer, the third etch solution having a faster rate of etch towards the second metal than towards the first metal to etch into said second metal layer without destroying the etched first metal layer. The first and second etch solutions comprise solutions with a pH below 10, preferably acidic solutions, and the third etch solution comprises a basic solution with a pH of at least 10.5, preferably a solution of alkali metal hydroxide with a pH of at least 11.0 containing an oxidizing agent.
Abstract:
A signal connector assembly with a plug contact (7) within a plug (6) having a high resistive portion (12). When each contact (7) of the assembly first makes contact with an associated electrical contact (15) within a mating receptacle (8), the high resistive portion (12) prevents a voltage surge. As the plug (6) is further inserted into the receptacle (8), the energy passing from the plug (6) to the receptacle (8) is gradually increased. Eventually, the receptacle contacts (15) within the receptacle (8) pass the high resistive portions (12) of the plug contacts (7) and make contact with conductive portions (14) of the plug contacts (7), thereby permitting transmission of valid signals without the generation of spurious errors.
Abstract:
Es wird eine Anordnung mit einer Leiterplatte (10), mindestens einem Leistungsbauelelment (14) und einem Kühlkörper (16) vorgeschlagen. Das Leistungsbauelement (14) ist an einer ersten Hauptoberfläche der Leiterplatte (10) auf einer ersten großflächigen Leiterbahn (120), die von den übrigen, an dieser Hauptoberfläche befindlichen Leiterbahnen elektrisch isoliert ist, oberflächenmontiert. Auf der dem Leistungsbauelement (14) gegenüberliegenden zweiten Hauptoberfläche der Leiterplatte (10) befindet sich eine zweite großflächige Leiterbahn (130), die mit dem Kühlkörper (16) gut wärmeleitend verbunden ist. Die beiden großflächigen Leiterbahnen (120, 130) sind miteinander über Durchkontaktierungen (100) gut wärmeleitend verbunden.
Abstract:
Die Oberfläche einer Metallfolie, wie sie namentlich als Zwischenlage in Leiterplatten Verwendung findet, wird auf photochemischem Weg aufgerauht. Die Teilschritte basieren auf gängigen Verfahrensschritten. Es werden feine Vertiefungen aus der Metallschicht herausgeätzt oder Erhöhungen aufplattiert. Die Anwendung des Verfahrens bzw. die Verwendung der Folie bei der Herstellung mehrlagiger Leiterplatten mit Schichten unterschiedlicher Wärmedehnung verbessert die Haftung mit der darauf angebrachten, nächsten Leiterbahnenlage wesentlich und verhindert ein delaminieren.
Abstract:
A printed circuit board substrate is provided wherein a composite metal layer (4, 5) is affixed to at least one surface of a flexible dielectric substrate (2, 3), the composite metal layer comprising an inner aluminium layer (4) and an outer copper layer (5).
Abstract:
57 After the process of manufacturing a cell of a display device a thick film conductor is bonded onto the terminal portion of a transparent electrode of the display panel by a dry or wet transfer mounting method and a flexible print circuit board for a driver is soldered on the thick film conductor, such a display device; a process for producing the display device; and a decal for dry or wet transfer mounting method to form a display panel terminal.