Flat module

The invention relates to a printed circuit board assembly, consisting of a lamp equipped with electrical components PCB, a connector portion having a plurality of contact elements and a, a print on a circuit board surface exerting Andruckbauteil, for example, a cooling device.

In the construction of large electronic systems, such as data processing equipment, the aim is to obtain the shortest possible signal lines with a defined wave impedance and thus to achieve high switching speeds. This can be accomplished by means of printed circuit board assemblies, having single- or multilayer printed circuit boards with integrated modules and which are connected via electrical connectors with a wiring board. This is in order to achieve a high density printed circuit, also carried out in multiple layers, and includes signal lines for connecting modules to each other, but also potential and supply lines. For PCBs highest density the necessary number of external connections are distributed in a confined space on the bottom, to make the connection to the PCB directly.

From US Patent 3,993,123 a printed circuit board with heat-emitting devices are known that are ankontaktiert on one side of a support plate. You are under a cooling device that it surrounds like a cap, and press from which one or more resilient parts of a heat-dissipating element on every block. The pressure thus generated is derived on the plate edges which are flanged to the cooling device, wherein the carrier can undergo deflection, however.

Since a large number of vertically projecting plug pins mounted on the carrier plate, impaired deflection plugging and pulling the printed circuit board, which is known to accurately mutually parallel pins requires. Otherwise there is a risk that pins are bent or broken, and that arise from faulty connections, or at least that even more plug-and pulling forces have to be applied, as they are necessary in any case because of the large number of compounds. Furthermore, with one of the mechanical stress evasive PCB risk that fissures in the affected circuit traces arise and break the connections. This can happen even more, even if the pins are firmly connected to the circuit board, and the existing deflection increases on the one hand by pulling forces with frequent change of printed circuit board and on the other hand restored by the elasticity of the board again, which can lead to fatigue of the conductor material ,

The invention was therefore based on the object to form a connector provided with a partial PCB of the aforementioned type in such a way that from mating and unmating operations resulting errors can be reduced. This object is achieved in that on the side opposite the Andruckbauteil side of the PCB pads are equal arranged moderately distributed so that the connector part about this whole side surface, and in that it above the contacting surfaces openings for the contact elements, each consisting of a spring shaft and consist of a spring formed as a pressure, applied to the contacting under spring tension terminal lug. In this way, unilateral pressure forces acting on the circuit board, so that no deflection occurs. By selecting the spring constant of the connection lugs of the counter-pressure on the printed circuit board is pre-adjustable. In addition, since the contact elements are not rigidly connected to the circuit board, do not lead the forces occurring during insertion and removal to a deflection of the circuit board. Thereby, cracks and fractures in traces or in solder joints, resulting from a static or dynamic force, prevented.

According to one embodiment of the invention, the terminal lugs are constructed as curved leaf springs. If the connection lugs are firmly connected to the pads, the contact reliability is increased, which can be further improved by the fact that the Federschäfte each connected from three U-shaped with one another, there are a receiving channel for a pin-forming side panels, and that at least one of the U- leg having a resilient portion for pressing against the contact pin.

The Federschäfte the contact elements are fixed each advantageously by a Einschnappverriegelung in the openings of the connector portion. If the connection lugs formed with respect to their dimensions so that the entire contact element can be inserted into an opening, then an assignment of fasteners and pads for different PCBs are selectively performed.

Following developments of the invention, the circuit board is fitted in a first recess of the connector part and the Andruckbauteil in a second recess parallel to the PCB into the connector part. This leads to a compact construction of the printed circuit board assembly, and furthermore has the advantage that the entire printed circuit board is enclosed by the connector part, so that it absorbs all the forces during insertion and removal.

In the following the invention with reference to an embodiment shown in the two figures will be further explained.<ul><li>1 shows a printed circuit board assembly,</li><li>2 shows a cross section through the printed circuit board assembly according to FIG. 1</li></ul>

The printed circuit board assembly, as shown in Figure 1 is determined in its external form of a plate-like connector part 3, which is one with a first and a second, to one of the flat sides opening cutout 1, 14 for receiving a printed circuit board 7 and is provided with screw 17 fixed Andruckbauteils. 4 This may for example consist of a metal plate as a cooling device for the heat-emitting components de serves r PCB. The connector part 3 has in its base 6 in the region of the first recess 1 a plurality of grid-like distributed, rectangular openings 2 for contact elements 9, 18, ​​and together with the resulting through the recess 1, 14 collar, a rim of the printed circuit board assembly.

Figure 2 shows a cross section through the printed circuit board along the dotted line 11 in Figure 1. In a breakthrough 2 is a Einschnappverrieglung a contact element 9.18, consisting of a spring shaft 18 and designed as a compression spring connecting lug 9 fixed. The spring shaft 18 consists of three U-shaped interconnected, a receiving channel for a contact pin (not shown) forming side parts, wherein the two U-legs have arched, funnel-shaped narrowing the receiving channel, resilient middle sections. They produce a double pressing contact when receiving a contact pin. The U-leg sit in front of the inner openings of the through-holes 2 on the first lugs 12th To lock the contact-9, 18 directed towards the outside opening of the through-holes 2 tongue 11 spreads on the spring shaft 18 which is engaged behind a second nose 10 in the opening. 2

The connecting tab 9 comprises a curved leaf spring, the radius of curvature and leaf width are such that the entire contact element 9, 18 can be inserted into an opening. 2 The sheet is therefore not wider than the breakthrough 2, and the diameter of curvature corresponds approximately to the length of the opening 2, bearing in mind that the winding diameter can decrease under pressure. The free end of the leaf spring extends into the first recess 1 and generates a vertically acting spring pressure on it with respect to the side edges tight-fit PCB. 7

This is below the breakthroughs 2 pads 8, press to which the terminal lug, 9, etched evenly distributed. The terminal lugs 9 this could have also been a soldered connection. On the opposite side, a plurality of integrated micro blocks 5, one of which is shown, ankontaktiert via connecting wires 13 by means of a film assembly technology. For their connection to each other and to the pads 8 extend several layers of etched conductive traces in the printed circuit board. 7

About the Andruckbauteil 4 a pressure on the blocks 5 is applied, for example, to produce a good thermal contact, which is transmitted to the printed circuit board 7 and would result in a deflection, if he were not annulled by the spring pressure of the terminal lugs. An adequate and uniform force between the terminal lugs 9 and the pads 8 is achieved in that the terminal lugs are 9 overstretched before assembly. The terminal lugs 9, and the contact elements 9, 18 are distributed such that a uniform surface pressure is generated on the circuit board. 7 Also in this manner a flexible connection between the connector part 3 and the circuit board 7 is manufactured.