Abstract:
A method of preparing printed circuit boards in which the solder mask is applied over a thin layer of copper oxide covering the copper circuit traces of a board, the copper oxide layer being that which remains after stripping the tin or tin-lead alloy etch resist in two stages using two stripper compositions. This permits an improved adhesion of the solder mask to the copper via the copper oxide provided by the invention.
Abstract:
Substrat multicouche de cablage dans lequel les configurations de cablage sont disposees dans des couches superieures et inferieures. Une feuille de cuivre (27) est laminee avec une couche de resine isolante (25) sur le premier substrat de cablage (24) deja recouvert de la premiere configuration de cablage (33), et les configurations superieure et inferieure (23) et (33) sont connectees au moyen d'une substance conductrice (34) deposee dans des ouvertures (32) de la deuxieme configuration de cablage (33). Ce substrat multicouche de cablage peut ameliorer la qualite, peut etre produit a peu de frais et peut former un circuit a haute densite.
Abstract:
Es wird eine Leiterplattenanordnung mit einer Trägerplatte (1), einer Leiterbahn (2) auf der Trägerplatte (1) und an der Anordnung zur Strombegrenzung angegeben. Die Leiterbahn hat einen Sicherungsabschnitt (23), der sich von einem ersten zu einem zweiten Leiterbahnabschnitt (21, 22) erstreckt und diese elektrisch leitend zu verbinden. Die Anordnung zur Strombegrenzung weist einen Lotbump (3), ein Heizelement (4) zum zumindest teilweisen Aufschmelzen des Lotbumps (3) und einen Opferbereich (231) des Sicherungsabschnitts (23) auf. Der Lotbump (3) grenzt an den Opferbereich (231) an, der dazu vorgesehen ist, in dem zumindest teilweise aufgeschmolzenen Lotbump (3) gelöst zu werden um den Sicherungsabschnitt (23) zu unterbrechen. Der Opferbereich (231) des Sicherungsabschnitts (23) hat einen kleineren Querschnitt als der erste und der zweite Leiterbahnabschnitt (21, 22).
Abstract:
The present invention relates to a printed circuit board arrangement (400) and a method for forming an electrical connection at a printed circuit board. The printed circuit board arrangement comprises a printed circuit board (410) having a first side (411), a second side (412) and an electrical connection (413) electrically connecting a first conductive layer and a second conductive layer (417) of the printed circuit board. The electrical connection (413) comprises a passage (416) extending from an opening in one of the sides of the printed circuit board through the printed circuit board between the first and second layers. Electrically conducting material (414) is formed on the walls (415) of the passage. The electrically conducting material forms a first path electrically connecting the first conductive layer (417) with the second conductive layer (417). At least one first ball 420 is enclosed by the passage. The at least one firstball is electrically conducting and has a diameter which is equal to or smaller than the length and diameter of the passage, wherein the at least one first ball (420) form part of a second electrical path between the first and second conductive layers of the printed circuit board, said second electrical path having a lower resistance than the first path.
Abstract:
A method is for making an electrical inductor. The method includes forming a first subunit having a sacrificial substrate, and an electrically conductive layer defining the electrical inductor and including a first metal on the sacrificial substrate. The method includes forming a second subunit having a dielectric layer and an electrically conductive layer thereon defining electrical inductor terminals and having the first metal, and coating a second metal onto the first metal of one of the first and second subunits. The method includes aligning the first and second subunits together, heating and pressing the aligned first and second subunits to form an intermetallic compound of the first and second metals bonding adjacent metal portions together, and removing the sacrificial substrate.