Manufacturing process for printed circuits

#The present invention generally relates to a manufacturing process for printed circuits that includes a machining step for shaping a design for the printed circuit with maximum safety and efficiency. More specifically, the invention refers to a technology change in the manufacture of printed circuits that is most useful in making the type to be integrated into service boxes within vehicles.

#Manufacturing processes, such as the ones disclosed in the Spanish Patent No. P9200325, which has common ownership with this application, are known. The increase in performances and therefore in the functions offered to a vehicle user requires a continuous improvement in quality, cost-effectiveness and size of the service boxes that contain the printed circuits. The size of the service box must be increased if there is a desire to follow with the practice of integrating the entirety of the printed circuits, plus the functions entrusted to the same, within a single service box.

#All that has as a consequence that the space problem is most relevant. Even if the advancement in the integration of printed circuits as is disclosed in Spanish Patent No. P9501610 (having common ownership with this application) are important, the functions and performances mentioned above are still growing, since manufacturers are increasingly offering, even in compact cars or relatively lower-cost vehicles, performances and functions that were previously offered only in top class models.

#FIG. 1 is an elevational, cross-sectional view of a conventional copper plate useful for printed circuit manufacturing.

#FIG. 2 illustrates the plate of FIG. 1 after it has been subjected to a chemical machining or chemical cutting process.

#FIG. 3 is an elevational, cross-sectional view of the embodiment of FIG. 2 with an injection molded dielectric substrate attached.

#The operations integrating the printed circuit manufacturing process of this invention begin with a copper plate 10 having an upper face 11 and a lower face 12. As shown in FIG. 2, chemical machining or cutting is used to produce grooves or inter-tracks 13 as indicated by the arrows. FIG. 2 is a schematic and illustrative illustration of one embodiment of this invention.

#There follows after the chemical cutting or machining process, an injection molding process to fold a fully dielectric material or substance of a generally plastic type within the machined grooves 13. The injection molded material most preferably is capable of withstanding high temperatures, since afterwards the assembly preferably is introduced into a wave welding machine for purposes that will become apparent below. If the plastic is not of such special characteristics, it could not withstand the temperature and distortions could be produced in the printed circuit that is manufactured.

#The injection molding operation serves two basic purposes. First, it gives the necessary dielectric support to the printed circuit. Second, it efficiently protects the inter-tracks 13 formed in the copper plate, in which can be seen that the walls of the grooves or inter-tracks are nearly fully vertical (i.e., perpendicular to the outside face of the copper plate). The injection molded dielectric also gives a certain mechanical stiffness to the assembly.