Patent Application
20090117324
Cavities on electronic substrates are required for many applications. The cavities are typically required to be drilled, into the substrate, but not all the way through. Electronic connections, such as conductive pads may be located within the cavities. As electronic substrates become smaller, the precision required in the drilling operation increases substantially, which causes the drilling operation to become very expensive. In addition, locating the pads within the drilled cavities becomes more difficult as the substrates become smaller.
Electronic substrates and methods of making electronic substrates having cavities formed thereon are disclosed herein.
The circuit board 104 may be a rigid-type or flexible-type circuit board. The circuit board 104 has a first side 110 and a second side 112 located opposite the first side 110. The sides 110, 112 are surfaces of the circuit board 104. The second side 112 of the circuit board 104 is located proximate the adhesive film 106. Electronic traces and the like (not shown in
The adhesive film 106 may he referred to as a bonding film or a lamination material. The adhesive film 106 has a first side 116 and a second side 118 located opposite the first side. The sides 116, 118 constitute surfaces of the adhesive film 106. The first side 116 of the adhesive film 106 is attached to the second side 112 of the circuit board 104. In some embodiments, the first side 116 of the adhesive film 106 comprises an adhesive and the first side 116 of the adhesive film 106 is adhered to the second side 112 of the circuit board 104. In some embodiments, an adhesive may be applied to the second side 112 of the circuit board 104 or the first side 116 of the adhesive film 106 and the adhesive film 106 may be subsequently adhered to the second side 112 of the circuit board 104.
As described in greater detail below, the adhesive film 106 may have portions cut out so that the adhesive film 106 does not cover any pads or other contacts located on the second side 112 of the circuit board 104 that require electrical connections. In other embodiments, the adhesive film 106 may be applied to the second side 112 of the circuit board 104 as a continuous sheet. Portions of the adhesive film 106 may be cut out of the continuous sheet in order to enable electrical connections to be made to pads or other contact points on the circuit board 104.
The material 108 may comprise pre-molded or pre-cut (include drilled), Polyethylene (PET), polyphthalamide, liquid crystal polymer, FR-4 or other materials. In some embodiments, the material 108 is rigid and may be more rigid than the circuit board 104. In some embodiments, the material 108 may be able to withstand high temperature, such as the temperature required to bond or solder components to the circuit board 104.
The material 108 has a first side 122 and a second side 124 located opposite the first side 122. The sides 122, 124 are surfaces of the material 108. The first side 122 of the material 108 is adhered to the second side 118 of the adhesive film. With additional reference to
The embodiment of the substrate 100 of
An embodiment of manufacturing the substrate 100 includes manufacturing the circuit board 104. The adhesive film 106 is then applied to the second side 112 of the circuit board 104. As stated above, the adhesive film may have portions cut out so as not to interfere with traces 140, pads 142, and other conductive points and components located on the second side 112 of the circuit board 104. In other embodiments, the adhesive film 106 maybe a continuous sheet.
The material 108 is manufactured to have the cavities 130 located therein. The cavities 130 may extend between the first surface 122 and the second surface 124 of the material 108. As stated above, the cavities 130 may be drilled or preformed, such as being molded with the material. 108. The material 108 may also be die set punched. The cavities 130 may be located in areas where contacts or components are located on the second surface 112 of the circuit board 104. The material 108 is adhered to the second side 118 of the adhesive film 106. Thus, the substrate now exists with cavities 130 located thereon. In embodiments where the adhesive film 106 is a continuous sheet, portions of the adhesive film 106 located proximate the cavities 130 may be removed. Removal may be accomplished via mechanical or chemical processes. In some embodiments, the circuit board 104, the adhesive film 106, and the material 108 are laminated together.
