Patent Application
20070259541
The present invention relates to electrical interconnection devices having a metal substrate for holding contacts, and to methods for making such interconnection devices.
Electrical interconnection devices are used to electronically couple components, such as a microprocessor, to a printed circuit board. Typical interconnection devices use multiple metal contacts to transmit electronic signals between the components. Increasing the rate of transmission and decreasing the overall size of the interconnection devices have been ongoing goals of the industry.
To improve the rate of transmission of these electronic signals efforts have been made to increase the density of the connections within the interconnection device. In some interconnection devices, injection molded plastic housings are used to receive and support a plurality of electrical contacts. However, the True Position (TP), geometry and co-planarity across the plastic housings are limited by the response and variability of the polymer to the injection molding process. In addition, such plastic housings may be susceptible to shrinkage, warping, bowing and bending. Also, it is beneficial to shield the signal contacts from one another and prevent cross-talk therebetween. However, while these plastic housing structures may isolate the metal contacts from one another, they do not provide shielding. To shield the signal contacts and provide a larger ground path than is typically available in such non-conductive connectors, the plastic housing structures may be metallized or may be equipped with ground planes. Nevertheless, it may be difficult to manufacture plastic housings that meet the demands for increasingly small connectors. The thin walls separating the contacts may be weak and susceptible to breakage.
As disclosed in disclosed in U.S. Pat. No. 6,945,788 to Trout et al., rigid metal substrate structures have been proposed as an alternative to the plastic housings for supporting the signal contacts. These metal substrate structures may be sized to fit within a plastic housing and include a plurality of apertures sized to receive the signal contacts. The metal substrate structure provides a rigid substrate that is resistant to shrinkage. To insulate the signal contacts from one another and to secure the signal contacts within the apertures, each signal contact may be overmolded with an insulative plastic, which is swaged to the substrate. Although effective in insulating the signal contacts, the process of overmolding each individual signal contact adds time and expense to the manufacturing process. Accordingly, it is desirable to provide an electrical interconnection device that achieves high contact density in a robust package that is economical to produce.
The present invention provides connector apparatuses for interconnecting components and methods for making such connectors. In one form, the present invention provides an electrical interconnection device for receiving and holding a plurality of electrical contacts. The electrical interconnection device includes a metal support substrate having an array of contact receiving apertures extending therethrough. Each of the contact receiving apertures is defined by an aperture wall and the contact receiving apertures are adapted to receive the plurality of electrical contacts. The electrical interconnection device also includes a dielectric layer coating the aperture wall. The dielectric layer insulates the plurality of electrical contacts from the substrate and holds the contacts in position within the contact receiving apertures.
In one aspect of the above-described embodiment, the metal support substrate is formed of a plurality of metal layers stacked atop and bonded to one another. The dielectric layer may be formed of a dielectric, non-conductive material such as a plastic, a ceramic or glass. The dielectric coating may be applied in a liquid, solid or gas form to the apertures by any known technique, including for example, electrostatic fluidized bed, liquid dip coating, electrodeposition, vapor deposition, overmolding and spray coating.
In another form, the present invention provides a electrical interconnection device for connecting an electrical device to a circuit board. The electrical interconnection device includes a support substrate formed of metal and having a top surface and an opposing bottom surface. The support substrate includes a plurality of contact receiving apertures extending therethrough from the top surface to the bottom surface. Each of the plurality of contact receiving apertures is defined by an aperture wall. A dielectric layer coats the aperture wall and at least a portion of the top and bottom surfaces. A plurality of electrical contacts extend through the plurality of contact receiving apertures. The dielectric layer insulates the plurality of electrical contacts from the metal layers of the support substrate.
In yet another form, the present invention provides a method for manufacturing a electrical interconnection device. The method includes the steps of constructing a metal support substrate having a top surface and an opposing bottom surface, and forming a plurality of electrical contact receiving apertures extending through the metal support substrate from the top surface to the bottom surface. Each of the plurality of electrical contact receiving apertures is defined by an aperture wall. The method also includes the step of coating the aperture wall of each of the plurality of electrical contact receiving apertures with a dielectric composition.
The step of coating the aperture wall may include applying the dielectric composition in a liquid, powder or gas form to the apertures by a technique, such as electrostatic fluidized bed, liquid dip coating, electrodeposition, vapor deposition, overmolding and spray coating.
The above mentioned and other features and objects of this invention, and the manner of attaining them, will become more apparent and the invention itself will be better understood by reference to the following description of an embodiment of the invention taken in conjunction with the accompanying drawings, wherein:
Corresponding reference characters indicate corresponding parts throughout the several views. Although the drawings represent embodiments of the present invention, the drawings are not necessarily to scale and certain features may be exaggerated in order to better illustrate and explain the present invention. Although the exemplification set out herein illustrates embodiments of the invention, in several forms, the embodiments disclosed below are not intended to be exhaustive or to be construed as limiting the scope of the invention to the precise forms disclosed.
The embodiments hereinafter disclosed are not intended to be exhaustive or limit the invention to the precise forms disclosed in the following description. Rather the embodiments are chosen and described so that others skilled in the art may utilize its teachings.
Referring to
As illustrated in
Turning now to
Referring still to
It should be understood that, although support substrate 12 is illustrated as having seven metal layers 26a-26g, the support substrate of the present invention may have any number of layers. Further, each of layers 26a-26g need not be of equal thickness, but may vary in thickness. In addition, the overall thickness of substrate 12 may vary. It should also be understood that support substrate 12 may be formed of a single metal layer, rather than a laminate of multiple metal layers, as shown in
Referring still to
The dielectric material may be applied to support substrate 12 using any suitable coating techniques including, for example, electrostatic fluidized bed methods, liquid dip coating methods, electrodeposition methods, vapor deposition methods, overmolding and spray coating. In one particular embodiment, the Scotchcast™ Electrical Resin 5230N is applied using an electrostatic fluidized bed method. Dielectric layer 16 has a thickness td, which may vary depending on the size and structure of contact 18 and aperture 14. In one particular embodiment, dielectric layer 16 has a thickness td of between about 0.075 mm to 0.125 mm (0.003 inches-0.005 inches).
As suggested above, the dielectric material may be applied to aperture wall 20 of each of apertures 14 such that dielectric layer 16 coats aperture wall 20. The dielectric material may also be applied to a portion of top and/or bottom surfaces 22, 24 of support substrate 12 proximal apertures 14 to provide further insulation between contact 18 and metal support substrate 12. The efficiency of the manufacture of connector apparatus 10 may be further improved by avoiding the selective application of the dielectric material to aperture wall 20 and a portion of top and bottom surfaces 22, 24 and, instead, applying the dielectric material to all exposed surfaces of support substrate 12 including aperture wall 20 and top and bottom surfaces 22, 24. It should be understood that aperture wall 20 of every one of the plurality of apertures 14 need not be coated. For instance, it may be desirable to only coat a selected one or few of apertures 14, in which case, those apertures 14 not requiring dielectric layer 16 may be plugged during the application of the dielectric material.
Referring now to
Contacts 18 are directly loaded into coated apertures 14 by inserting lower pin contact 40 through, and forcing body 36, into aperture 14. As body 36 is positioned in aperture 14, body 36 biases and scrapes against dielectric layer 16, but does not penetrate dielectric layer 16. Once inserted into aperture 14, body 36 is held by interference fit against dielectric layer 16 in aperture 14.
Metal support substrate 12 provides connector apparatus 10 with a rigid and stable support structure that resists bending and bowing, while dielectric layer 16 insulates contact 18 from metal support substrate 12. Dielectric layer 16 also eliminates the need for overmolding or coating contacts 18 prior to loading in apertures 14, and allows contact 18 to be directly loaded into apertures 14.
Turning now to
While this invention has been described as having an exemplary design, the present invention may be further modified within the spirit and scope of this disclosure. This application is therefore intended to cover any variations, uses, or adaptations of the invention using its general principles. Further, this application is intended to cover such departures from the present disclosure as come within known or customary practice in the art to which this invention pertains.
