RF connectors with dispensable and formable insulative materials and related methods

A method for making an RF connector having an outer conductor and an inner conductor includes the steps of plating the outer conductor and the inner conductor of the RF connector with at least one corrosion-resistant metallic material; dispensing and/or injecting a material comprising an epoxy phenol novolac based resin. in a volume between the outer conductor and the inner conductor of the connector; heating the RF connector with the injected material to a temperature between about 150° C. to about 380° C. in a substantially dry nitrogen-based environment; and allowing the RF connector to cool.

BACKGROUND

The disclosure relates generally to radio frequency (RF) connectors and, more particularly, to connectors and connector assemblies, having formable insulative materials. Methods related to radio frequency (RF) connectors having formable insulative materials are also disclosed herein.

Currently, in connector assemblies, insulators and dielectrics are made of various types of non-conductive insulative materials. These materials include plastic, glass ceramic and epoxy materials. The main purpose of these types of insulative materials is to electrically isolate connector components from one another. In some cases, however, a secondary purpose of insulators and dielectrics is to hermetically seal the connector.

When used in a Radio Frequency (RF) connector; insulative materials provide a consistent and favorable dielectric constant to maintain specific impedance (25-300 ohms, more specifically 50-75 ohms). A dielectric constant of 1-10 is generally required, but a dielectric constant ranging from about 2 to about 5 is preferred. It is important that the dielectric constant be consistent over a wide range of operating frequencies (e.g. DC—140 GHz). Also, the dielectric constant should be low loss with a loss tangent less than 0.01.

Most connectors require some level of surface treatment, primarily nickel and/or gold plating, to ensure that connectors will not corrode. Corrosion can lead to changes in its electrical performance. Typically, plated parts cannot be subjected to high temperatures (450° C.) for a period of time generally ranging from about 3-5 minutes. For high-temperature applications, such as those having temperatures ranging from 165° C. to 400° C., glass ceramic materials are primarily used. However, current process temperatures for glass ceramics ranges from about 800° C. to about 1050° C. Thus, the process temperatures often exceeds acceptable levels for plated connector parts.

Another issue with using glass and ceramic dielectric materials is that glass pre-forms are typically required to be stocked for every size dielectric needed. New pre-forms are expensive and often have long lead times.

Consequently, there are several unresolved needs for improved insulative materials used in connector assemblies. There is a particular needs for methods of manufacturing insulators and dielectrics with the ability to withstand processes used in high temperature and hermetically seal environments, while employing materials and manufacturing processes which allow for pre-plated components.

SUMMARY

In accordance with certain embodiments of the present disclosure, one objective is to replace glass ceramics with at least one material, which can be processed at much lower temperatures (150° C.-380° C., vs. 800° C.-1050° C.), allowing for pre-plated parts to be processed.

In accordance with this objective, one aspect of the disclosure relates to a method for manufacturing an RF connector, which may or may not be coaxial, having an outer conductor and an inner conductor. The method includes the steps of plating the outer conductor and the inner conductor of the RF connector with at least one corrosion-resistant material, positioning the inner conductor and the outer conductor into a fixture assembly, dispensing at least one formable insulative material (e.g. via an automated cnc dispensing system) into a volume between the inner conductor and the outer conductor, and heating the RF connector and the dispensed insulative material to a temperature between a pre-determined temperature range. The step of dispensing is preferably achieved using jetting technology or syringe technology. Moreover, during the step of positioning, a portion of the inner conductor can be positioned within a first non-metallic fixture tier and a second non-metallic fixture tier and a portion of the outer conductor can be positioned within the first non-metallic fixture tier and the second non-metallic fixture tier.

Another method of manufacturing a connector having an outer conductor and an inner conductor includes plating the outer conductor and the inner conductor of the RF connector with a corrosion-resistant metallic material; positioning the inner conductor and the outer conductor such that a volume is formed between the inner conductor and the outer conductor injecting a material comprising an epoxy phenol novolac based resin into the volume formed between the outer conductor and the inner conductor, wherein defined in the outer conductor is at least one retention element; substantially filling the at least one retention element with the epoxy phenol novolac based resin during injection of the material; allowing air bubbles to escape from the outer conductor after the material is injected into the volume and the material is substantially filled into the retention groove; heating the RF connector with the injected material to a temperature between about 150° C. to about 380° C.; and allowing the RF connector to cool.

The insulative material comprises an epoxy phenol novolac resin, which is heated to a temperature between about 150° C. to about 380° C. The epoxy phenol novolac based resin preferably comprises a imidazole catalyst which is thermally cured.

Heating of the insulative material in the RF connector preferably occurs in a substantially dry nitrogen-based environment. Heating the RF connector with the dispensed material can further include heating the RF connector by an oven that uses a nitrogen and partial-vacuum atmosphere. After heating, the RF connector is allowed to cool.

Yet another embodiment of the disclosure is directed to a connector, manufactured by a method including the steps of pre-plating the outer conductor and the inner conductor of the connector with a corrosion-resistant material, e.g. a corrosion-resistant metallic materials, injecting a material comprising epoxy phenol novolac material in a volume between the outer conductor and the inner conductor of the connector, heating the connector with the injected material to a temperature between about 150° C. to about 380° C. in a substantially dry nitrogen-based environment, and allowing the connector to cool.

DETAILED DESCRIPTION

Various exemplary embodiments of the disclosure will now be described with particular reference to the drawings. Exemplary embodiments of the present disclosure may take on various modifications and alterations without departing from the spirit and scope of the disclosure. Accordingly, it is to be understood that the embodiments of the present disclosure are not to be limited to the following described exemplary embodiments, but are to be controlled by the features and limitations set forth in the claims and any equivalents thereof.

Cartesian coordinates are used in some of the Figures for reference and are not intended to be limiting as to direction or orientation.

For purposes of description herein, the terms “upper,” “lower,” “right,” “left,” “rear,” “front,” “vertical,” “horizontal,” “top,” “bottom,” “side,” and derivatives thereof, shall relate to the disclosure as oriented with respect to the Cartesian coordinates in the corresponding Figure, unless stated otherwise. However, it is to be understood that the disclosure may assume various alternative orientations, except where expressly specified to the contrary.

For the purposes of describing and defining the subject matter of the disclosure it is noted that the terms “substantially” and “generally” may be utilized herein to represent the inherent degree of uncertainty that may be attributed to any quantitative comparison, value, measurement, or other representation.

Processes/methods consistent with the disclosed embodiments herein relate to making or manufacturing RF connectors that facilitate the use of dispensable, formable, and insulative materials, which can be more flexibly formed and/or used at lower temperatures compared to traditional insulative materials used in RF connectors. Manufacturing RF connectors according to these methods can particularly avoid damage to plated components, which typically occur at high temperatures during prior art methods of connector manufacture. In addition, the insulative materials used in such processes/methods have performance characteristics that are usually associated with glass and ceramic dielectrics.

Processes/methods consistent with the disclosed embodiments involve the use of a dielectric comprising a low-dielectric epoxy phenol novolac based resin. This material is advantageous because its dielectric properties are similar to glass or ceramics and the material is capable of being processed at temperatures which will not deteriorate plating of connector components. Percentages of the epoxy phenol novolac based resin in the connector can range from about 75% to about 100%, about 50% to about 100%, about 25% to about 100%, about 15% to about 100%, about 10% to about 100%, and about 5% to about 100%. The remaining volume percentage of the material can include another proprietary resin material and/or another resin having similar dielectric properties. Processing temperatures for prior art processes/methods typically range from about 800° C. to about 1100° C.

In accordance with one embodiment, a method for manufacturing an RF connector includes the steps of plating an outer conductor with at least one corrosion resistant material101a, plating an inner conductor with at least one corrosion resistant material101a′, positioning the plated inner conductor and the plated outer conductor in a fixture assembly103to form a connector such that a volume is created between the inner conductor and the outer conductor, dispensing a material in the volume contained within the connector105. After the material is dispensed in the volume, another step in the method includes heating the dispensed material and heating the connector to temperatures within pre-determined temperature ranges107, and allowing the heated connector and the heated material to cool below specified cooling temperatures109, specifically to a cooled dispensed material temperature and a cooled connector temperature.

Additional steps include injecting a material comprising an epoxy resin in a volume between the outer conductor and the inner conductor of the connector, heating the connector with the injected material to a temperature between about 150° C. to about 380° C., and allowing the connector to cool to a temperature of about 20° C.

Indeed, processes and methods consistent with the disclosed embodiments are particularly useful when different sizes/shapes of dielectric material are present, since the dielectric materials used are injectable/flowable/formable under relatively low heat when compared with glass or ceramic components.

FIG.2is a cross-sectional view of an exemplary RF connector200positioned within a fixture assembly FA used in a method for manufacturing the RF connector. The RF connector200is exemplary and can include additional elements or different configurations, including those described with respect toFIGS.3-10. The RF connector200includes an inner conductor202and an outer conductor204. The connector200is shown with the dispensed insulative material206contained in a volume208contained within the connector200. The outer conductor204is configured to surround the insulative material206and the insulative material206is configured to surround the inner conductor202. In this exemplary configuration the outer conductor204is cylindrical and includes an inner diameter204a, an outer diameter204b, and a length204c. The inner conductor202has a center conducting pin configuration with pin portions202a,202b. The insulative material is dispensable and flowable. Thus the insulative material is configured to fill and complement profiles of the connector, as will be described particularly with reference toFIGS.4,6, and9. For the connector200, as particularly shown inFIG.2, the insulative material also takes a cylindrical form, which complements the inner profile204pof the outer conductor204and the outer profile202pof the inner conductor202. The profiles of the inner conductor and the outer conductor are configured to act as retention elements to secure the insulative material in the connectors disclosed herein.

Accordingly, the fixture assembly FA shown is exemplary as additional elements may be included and the configuration of the fixture elements may differ. However, elements included in the fixture assembly are such that the fixture assembly is configured to dispense and/or inject the insulative material and form an RF connector.

In this exemplary embodiment, the fixture assembly FA includes an upper fixture block210, a middle fixture block220, and a lower fixture block230. The upper fixture block210has a stepped configuration with two tiers212,214. The first upper fixture tier212includes an inner conductor opening216configured to receive a portion of the inner conductor202. And, the second upper fixture tier214includes an outer conductor opening218configured to hold a portion of the outer conductor204. The middle fixture block220also includes two tiers222,224. The first lower fixture tier222includes a connector holding area226configured to receive a portion of the inner conductor202and a portion of the outer conductor204. The middle fixture block220is also configured to but against the second upper fixture tier214of the upper fixture block210and lower fixture block230. The lower fixture block includes a thru-hole236configured to receive the second lower fixture tier224.

The upper fixture block210and the middle fixture block220are preferably manufactured from one or more materials having non-stick properties such that a connector can be removed from the fixture assembly FA without significant effort. Such materials can include polytetrafluorethylene, for example. In preferred configurations of the fixture assembly, the lower fixture block230comprises one or more metallic materials.

FIGS.3-10provide views of different embodiments of connectors and connector assembles, including elements that may be manufactured using the presently-disclosed processes/methods.

FIGS.3and4illustrate an exemplary feed-through connector300, which includes an inner conductor302, an outer conductor304, and a insulative material306, which has been formed in the volume308between the inner conductor302and the outer conductor304. The insulative material306is formed within the volume308such that the insulative material conforms to the inner profile304pof the outer conductor304and the outer profile302pof the inner conductor302. The inner profile304pof the outer conductor404has a stepped configuration and includes a radiused profile portion304pc. The stepped inner profile is defined by two profile diameters304d1,304d2, where the first profile diameter304d1is smaller than the second profile diameter304d2. The insulative material306also conforms to the outer profile302pof the inner conductor302. The outer profile302pis defined by profile diameters302d1,302d2such that the first profile diameter302d1is smaller than the second profile diameter302d2. The outer profile302pof the inner conductor302also includes a radius profile portion302pc, as shown particularly inFIG.4.

FIG.5is an isometric view of a multi-position block B, which may include connectors200,300or another type of connector having conductors with different profiles. The block B includes a block body500having plurality of bores560defined therein, in which the connectors200,300may be inserted.

FIG.6is a cross-sectional view of another exemplary connector400, which may be manufactured using the processes/methods disclosed herein. The connector400includes an inner conductor402, which is partially shown, an outer conductor404, and an insulative material406formed between a volume408contained within the inner conductor402and the outer conductor404. The insulative material406is formed within the volume408such that the insulative material conforms to the inner profile404pof the outer conductor304and the outer profile402pof the inner conductor402. The inner profile404pincludes a radiused profile portion404pc. The inner profile404pis further defined by two profile diameters404d1,404d2, where the first profile diameter404d1is smaller than the second profile diameter404d2. The inner profile404pcan additionally be defined by diameter404dc1, which corresponds to the innermost diameter of the radius profile portion404pc. The insulative material406also conforms to the outer profile402pof the inner conductor402. The outer profile402pis defined by a plurality of profile diameters. In this exemplary inner conductor, the outer profile402pis defined by at least profile diameters402d1,402d2,402d3,402d4,402d. The outer profile402pof the inner conductor402also includes tapered portions402t1,402t2.

FIG.7is an isometric view of another exemplary connector500that may be manufactured using the presently-disclosed processes/methods. The connector500includes an inner conductor502, an outer conductor504, and a insulative material506, which has been formed in the volume508between the inner conductor502and the outer conductor504. The insulative material506is formed within the volume508such that the insulative material conforms to an inner profile of the outer conductor502and an outer profile of the inner conductor502. Coupled to or integral with the connector is a housing component507, which can be used to facilitate connection to other components that may be assembled to the connector.

FIG.8illustrates a multi-contact connector600that may be manufactured using the presently-disclosed processes/methods. The connector600includes a plurality of inner conductors602, forming a multi-pin inner conductor, an outer conductor body602, and a insulative material606, which has been formed in the volume608between the inner conductor502and the outer conductor504. Each inner conductor602is configured to extend through the insulative material606.

FIG.9is a cross-sectional view of an angled connector700that may be manufactured using the presently-disclosed processes/methods. The connector700includes an inner conductor702, which has been angularly formed. In this configuration, the inner conductor702has an included angle α, of about 90 degrees. The outer conductor704includes bores705,708. In this connector type, the insulative material is dispensed and then formed within a bore708.

FIG.10illustrates a cross-sectional view of a female connector800, which can manufactured using the materials and processes/methods disclosed herein. The connector800includes an inner conductor802, an outer conductor804, and an insulative material806formed in a volume between the inner conductor802and the outer conductor804. The inner conductor802and the outer conductor804are positioned in the connector such that a socket is formed there. The inner conductor802has a curved profile802cand the outer conductor804has a solid center area804b, with an inwardly extending element814, and a plurality of deflectable and flexible arms804a,804con each end of the outer conductor. The insulative material806is formed between the inner conductor802and the outer conductor804such that the insulative material conforms to the curved profile802cof the inner conductor and the profile814pof the inwardly extending element814.