Various sealant compositions have been used to seal electrical connectors and protect the terminals within the connectors particularly when the connectors must be soldered to a substrate. Typically the procedures for mounting components to a substrate involve exposure to fluxes, solder, defluxing agents and cleaning agents. It is important that the chemicals and especially solder used during these processes do not migrate or wick into the connector housing, damage the terminals, and prevent the connector from being mated with a corresponding connector. With the increased use of miniaturized and closely spaced terminals it is especially important to prevent wicking of solder into the terminals. Even a minute amount of solder in terminals having a contact opening with a diameter on the order of 0.025 inches will prevent the terminal from proper electrical engagement when the connector is mated with a corresponding connector. Electro-optic devices and components of connectors, such as filters, and the like, frequently require sealants in the form of coatings and adhesives.
It is known to the art to seal connectors using anaerobic acrylate adhesives, epoxy resin adhesives, and cyanoacrylate adhesives. There are problems associated with using these sealants in sealed connectors owing to lack of heat resistance at elevated soldering temperatures and lack of resistance to cleaning chemicals.
It is an object of this invention to provide a sealant which is hydrophobic, will withstand soldering procedures and is resistant to corrosive cleaning solvents.
It is an additional object of the invention to provide a sealant for repairing and sealing electrical connector housings, components of connectors, and electro-optic devices, for filling joint gaps and also especially apertures around terminals and strengthening thereat the housing, components and devices against physical stresses.
It is also an object of this invention to provide a solder resistant sealant for use with electrical devices, such as filters and the like, having a plurality of isolated conductive areas thereon wherein one or more of the conductive areas must be soldered to other conductive areas.
Furthermore, it is an object of the invention to provide a solder and chemical resistant sealant for selected locations or areas of electrical devices that will protect and seal those locations during the life of the device.
In addition, it is an object of the invention to provide a cost effective means for sealing electrical components that is also usable in automated manufacturing systems.
It is a further object of the invention to provide a sealant which is curable by actinic radiation, particularly ultraviolet and visible light, or heat.
In addition, it is an object of the invention to provide a sealant which has a dual curing system specifically designed for combined photocuring and heat curing.
It is also an object of the invention to provide a sealant which will adhere well to plastics, metals, glass, and semiconductors such as ferrites and titanates.
Still further, it is an object of the invention to provide a process for sealing electrical connectors, components of connectors, and electro-optic devices.
Additionally, it is an object of this invention to provide a process to seal, repair and structurally reinforce foraminous electrical and electro-optical connectors.