Abstract: A flat circuit module assembly includes a circuit board and unpackaged, or housingless, chips mounted on its surface, with an elastic pressure pad between the circuit board and the chips. To achieve an adequate spring characteristic, the elastic pressure pad is dimensioned to be correspondingly thick, the consequence of which is that the Z bend of the terminal legs would be greater than would actually be needed for compensating for the thermal stress. To avoid this disadvantage, the invention provides depressions on the circuit board surface into which the pressure pads are placed. This reduces the tolerance range in the surface soldering area. The invention also provides that the circuit board is a multilayer board that has internal conductors, and further that the depression into with the pressure pad is placed extends to one of the internal conductive layers.

Abstract: A packaging system for electrical operational units is composed of several PC boards equipped with components of the so-called flat-pack type, which, on a component side, reside against coolant-permeated cooling plates and are supplied with operating and signal voltages from plugged and/or terminal connections. With the presently-known planar arrangement of such modules in a grid-type frame and with a joint coolant-permeated cooling plate, which lies on the side of the modules, considerable concentrations of components per volume unit could be achieved. The increasing requirements for computers with which an always increasing number of calculating operations is to be performed in the smallest space requires an always increasing concentration of components per volume unit, whereby the problem of heat removal and line supply becomes more acute.

Abstract: A mounting system for electrical function units, particularly for a data technology system is composed of an alternating sequence of cooling plates provided with cooling channels for a coolant and with through-contactings and of printed circuit boards constructed in microwiring technology. These printed circuit boards have contact areas on both of their surfaces for contacting the terminal contact pads of integrated components that in turn have their side not provided with terminal contact pads pressing against the cooling plates. External operating and signal voltages are supplied to the function units. Such a structure enables a high packing density of the components. In the mounting system the packing density of such components is further increased by connecting the terminal contact pads of the integrated components to the contact areas of the printed circuit boards directly via contact mats.

Abstract: A circuit board assembly for data equipment such as those having large numbers of layers and great power requirements in a small space having high computer performance, includes a multi-layer printed circuit board in laminated technology provided with voltage supply and signal carrying layers and pressure contacts at both sides connecting the multi-layer printed circuit board to further printed circuit boards. The further printed circuit boards, which are formed using micro-wiring technology, include backsides which are free of electrical components and connected to the pressure contacts and opposite sides carrying integrated electrical elements such as circuit chips forming an electrical circuit. Cooling plates are pressed against the surfaces of the circuit chips.

Abstract: Modified scanning electron microscopes are usually employed for the implementation of methods for testing the electrical properties of printed circuit boards with the electron probe. As a consequence of the deflection, chromatic aberration and of the aberrations of the objective lens increasing greatly with the deflection angle, however, their scanning field is limited. In order to be able to test larger printed circuit boards without involved improvement of electron optics, it is proposed that the printed circuit board be subdivided into a plurality of adjoining regions, whereby the size of the regions respectively approximately corresponds to the size of the scanning field. Each of the networks lying only within one of the regions is then tested in a known manner. In order to detect shorts between networks of different regions as well as interruptions between contact points of networks extending beyond regions, the known testing method is followed by a further test cycle.