This invention is generally directed to an interconnect device which is configured to connect a sensor to a connector. The interconnect device is used in an assembly. The sensor determines flow characteristics or other characteristics of a fluid.
Sensors which incorporate Micro-Electro-Mechanical Systems (MEMS) or a biological Micro-Electro-Mechanical Systems (BioMEMS) are now being used to determine characteristics of a fluid, such as flow rate, temperature, for the presence of biological agents, genetic diseases present in the fluid, infectious agents in the fluid, detection of metals, etc. These types of sensors allow for in field usage, such as on a battlefield, to determine the characteristics of the fluid, such as blood, to allow for the immediate treatment of the condition found as a result of the analysis using the MEMS or BioMEMS.
A sensor that incorporates MEMS is disclosed in U.S. Pat. No. 6,813,964. The sensor is housed in a housing that is formed of a molded plastic during an injection molding process. This process is time consuming and can be difficult to assure proper registration of the MEMS within the housing.
One object of the present invention is to provide a low cost way to seal a MEMS, or other measurement type device, in combination with an electrical interconnect device.
Another object of the present invention is to provide an assembly whereby the electrical interconnect device is not in direct contact with the fluid to be introduced into the measurement device.
Yet another object of the present invention is to provide electrical access to the measurement device that has been sealed in an overall assembly.
Briefly, the present invention discloses an assembly for mating a sensor to a connector. The assembly includes an interconnect device and a housing. The interconnect device may formed from a two-shot molded component and has conductive pathways provided thereon. The sensor is mounted on the interconnect device and is in electrical communication with the conductive pathways. The housing generally surrounds a portion of said interconnect device. The housing is formed of two interconnecting portions, which may be hermaphroditic, which mate together. At least one flow tube is attached to the housing. A gasket seals the sensor to the housing.
The organization and manner of the structure and operation of the invention, together with further objects and advantages thereof, may best be understood by reference to the following description, taken in connection with the accompanying drawings, wherein like reference numerals identify like elements in which:
While the invention may be susceptible to embodiment in different forms, there is shown in the drawings, and herein will be described in detail, specific embodiments with the understanding that the present disclosure is to be considered an exemplification of the principles of the invention, and is not intended to limit the invention to that as illustrated and described herein.
A first embodiment of the present invention is described with relation to
In each embodiment, the interconnect device 20, 120 is configured to connect a sensor 22, such as a Micro-Electro-Mechanical Systems (MEMS) or a biological Micro-Electro-Mechanical Systems (BioMEMS), to a connector 24. The sensor 22 is used to determine characteristics of a fluid, such as flow rate, temperature, for the presence of biological agents, genetic diseases present in the fluid, infectious agents in the fluid, detection of metals, etc. While terms such as “upper”, “lower”, “top”, “bottom”, “front”, “rear” and the like are used in describing the first and second embodiments of the invention, it is to be understood that these terms are not limiting with regard to the usage of the first and second embodiments of the invention in relation to the sensor 22 and to the connector 24.
As shown, the sensor 22 has a main body 25 that has a passageway 26 extending therethrough through which fluid can flow. A lip 27 extends from the main body 25 and has a height that is less than the height of the main body 25. The upper surface of the main body 25 and the lip 27 are planar. The sensor 22 includes components, such as a proportional microvalve, pressure sensors, a temperature sensor and calibration electronics, mounted on a silicon substrate. In one embodiment, the sensor 22 can be used to control the rate of the fluid flow through the passageway 26 through means known in the art by measuring the capacitance changes in the fluid flowing through the passageway 26. The sensor 22 can be used to determine characteristics of the fluid in the passageway 26, such as flow rate, temperature, for the presence of biological agents, genetic diseases present in the fluid, infectious agents in the fluid, detection of metals, etc. As shown, the sensor 22 has spaced apart leads 28 provided thereon for interconnection to the interconnect device 20, 120. Such a sensor is shown in U.S. Pat. No. 6,813,964, which disclosure is incorporated herein by reference.
The connector 24 is known in the art and includes a housing 30 having a cable 32 attached thereto and a plurality of terminals 34 within the housing 30. The ends of the terminals 34 extend from the housing 30 and are spaced apart from each other predetermined distances.
The interconnect device 20, 120 is disposable (but mates with a high wear life mating connector 24, i.e., greater than several thousand cycles), is low cost to manufacture, and the parasitic capacitance of the interconnect device 20, 120 is very low (i.e., less than 0.5 pf). The interconnect device 20, 120 is preferably formed by a high cavitation, two-shot molding process and a plating process. The high cavitation, and two-shot molding process keeps the cost of manufacturing the interconnect device 20, 120 low.
Attention is invited to
The non-plateable portion 36 formed in the first shot of the molding process includes a generally rectangular connector portion 44 with a generally rectangular base portion 46 extending perpendicularly therefrom at a midpoint thereof.
The connector portion 44 has a top surface 48, a front surface 50, a tapered surface 52 formed between the top and front surfaces 48, 50, a bottom surface 54, a rear surface 56 and end surfaces 58, 60. A pair of passageways 62, 64 are formed in the connector portion 44 proximate to, but spaced from, the end surfaces 58, 60. The passageways 62, 64 are open to the top surface 48, the front surface 50 and to the bottom surface 54. Walls 66, 68, which also form part of the bottom surface 54, partially close the bottom end of the respective passageways 62, 64 such that recesses 70, 72 are formed.
The base portion 46 has a first section 74 that has a top surface 76 that is flush with the top surface 48 of the connector portion 44 and a second section 78 that is stepped downwardly from the first section 74 such that it is parallel to, but offset from the first section 74.
As best illustrated in
The second shot of molding which forms the plateable portions 38 of the interconnect device 20 is deposited into the channels 80 formed in the non-plateable portion 36. As a result and as best illustrated in
The conductive material, which forms the conductive pathways 40, plated onto the plateable portions 38 forms a deposit on the plateable portions 38. As a result, each conductive pathway 40 is formed of a first portion 94, a second portion 96, and a third portion 98.
As shown in
The third portions 98 of the conductive pathways 40 and the top surface of the connector portion 130 provided therearound define a solder or wire bond pad area. A solder paste (not shown) is deposited either on the leads 28 of the sensor 22 or on the third portions 98 of the conducive pathways 40 in the solder or wire bond pad area. The sensor 22 is positioned on the second section 78 of the base portion 46 as shown in
Attention is now invited to
The interconnect device 120 is best illustrated in
The connector portion 124 has a top surface 130, a front surface 132, an upper tapered surface 134 formed between the top and front surfaces 130, 132, a bottom surface 136, a bottom tapered surface 137 formed between the bottom and front surfaces 136, 132, and end surfaces 138, 140. A locking bump 150a, 150b is formed on the top surface 130 and on the bottom surface 136 of proximate to, but spaced from, the tapered surfaces 134, 137. Each locking bump 150a, 150b extends the entire width of the connector portion 124 between the end surfaces 138, 140.
The base portion 126 has a first section 142 which has a top surface 144 that is flush with the top surface 130 of the connector portion 124 and a bottom surface 145 that is stepped from the bottom surface 136 of the connector portion 124, and a second section 146 having a top surface 148 stepped downwardly from the top surface 144 of the first section 142 and a bottom surface 149 planar with the bottom surface 145 of the connector portion 124. A pair of shoulders 152a, 152b are formed on the front end of the first section 142 of the base portion 126. The shoulders 152a, 152b are generally cubically shaped and extend upwardly from the top surface 144 of the first section 142.
Conductive pathways 154 are formed along the connector portion 130 and the first section 142 of the base portion 126. The conductive pathways 154 extend generally from the front surface 132 to the rear edge of the first section 142 along the top and bottom surfaces 130, 144; 136, 145. The conductive pathways 154 extend over the locking bumps 150a, 150b. The conductive pathways 154 are generally flush with the surfaces 130, 132, 134, 136, 137, 144. As shown in
The tab portion 128 has first, second and third sections 162, 164, 166. The first section 162 extends from a rear edge of the base portion 126 and is perpendicular thereto. The second section 164 extends from the upper edge of the first section 162 and is perpendicular thereto. The first and second sections 162, 164 have the same width as the base portion 126. A tapered edge 168 is provided between the first and second sections 162, 164. The third section 166 extends from the second section 164 and is planar with the second section 164. The third section 166 forms a finger grip and has an enlarged width relative to the second section 164. A height of the third section 166, defined as a distance from an upper surface 170 to a lower surface 172 thereof, alternates between a reduced height portion and an increased height portion along the length thereof.
The interconnect device 120 is preferably formed using a two-shot molding process and a plating process, although the present invention is not limited to such a forming method. Rather, any available manufacturing method used to manufacture electrical connection devices may also be used to manufacture the electrical interconnect 120.
To form the interconnect device 120 using a two-shot molding process, a plateable material, such as a liquid crystal polymer which is palladium doped, is shot in a first mold to form a plateable portion. The plateable portion includes most of the same parts of the interconnect device 120, which are provided on a smaller scale than the identical parts provided on the interconnect device 120. For instance, the plateable portion includes a scaled down version of the connector portion 124, the base portion 126 and the tab portion 128. The plateable portion, however, includes the conductive pathways 154 provided on the connector portion 124.
The plateable portion is then transferred to a second mold and a non-plateable material, such as silicone, is selectively shot in the second shot, using liquid injection molding (LIM), onto the plateable portion to form a non-plateable portion. The non-plateable material is overmolded onto all of the scaled down parts of the plateable portion, but does not cover those areas of the scaled down connector portion 124 and the base portion 126 at the location of the conductive pathways 154. The non-plateable material on the plateable portion gives the interconnect device 120 a spongy/textured feel to the user of the assembly 118.
Thus, the non-plateable portion constitutes the entire exposed/visible portion of the interconnect device 120, other than where the conductive pathways 154 are formed on the connector portion 124. Prior to the interconnect device 120 having the conductive pathways 154 formed thereon, portions of the plateable portion (hereinafter referred to as the traces (not shown)) are exposed/visible as they were not overmolded by the non-plateable material. The traces are then etched using suitable known means in order to expose the palladium of the plateable material. The plateable and non-plateable portions are then subjected to a plating process using known means in one or more metallicized baths, such as a copper bath, a nickel bath, a gold bath, etc., as desired in order to form the conductive pathways 154 onto the traces having the exposed palladium.
For methods of forming the interconnect device 120 other than two-shot molding, the portion of the interconnect device 120 identified as the conductive pathways 154 need merely be formed with a conductive material, and the remainder of the interconnect device 120 is formed with an insulative material.
In use, a solder paste (not shown) is deposited either on the leads 28 of the sensor 22 or on the third portions 160 of the conducive pathways 154 in the solder or wire bond pad area. As shown in
The flow tube assembly 122 is preferably formed of plastic, such as PBT or polycarbonate. The flow tube assembly 122 is formed of hermaphroditic housing portions 174a, 174b, which may be hermaphroditic as set forth herein, which are mated together and a gasket 176 mounted within each housing 174a, 174b. One of the housings 174a is described, with the understanding that the other housing 174b is identical in construction and is denoted with identical reference numerals and having the suffix “b”. One of the gaskets 176 is described, with the understanding that the other gasket 176 has similar construction regarding the features relevant to the present invention.
As shown in
The gasket 176, which is preferably formed of an elastomeric material such as silicone, is insertable into the recess 212a and can be held therein by an interference fit or by mechanical means. A passageway 216 is provided therethrough and is in fluid communication with the passageway 210a in the second section 184a and the passageway in the tube 178a. A recess 218 surrounds the passageway 216 and extends from the surface facing the first section 182a inwardly a predetermined distance. The recess 218 has a shape that is identical to the profile of the end of the sensor 22 having the passageway 26.
In use, a gasket 176 is inserted into the recess of each housing 174a, 174b as shown in
The interconnect device 120 which has the sensor 22 mounted thereon, is then engaged with one of the housings 174a as shown in
Thereafter, as shown in
As shown in
Because the interconnect device 120 and the sensor 22 are mated together prior to being assembled with the flow tube assembly 122 this allows for non-high temperature material to be used for the flow tube assembly 122 since these components will not be subjected to the reflow process. In this second embodiment, soldering the sensor 22 to the interconnect device 120 prior to assembly with the housings 174a, 174b also provides for more accurate alignment of the leads on the sensor 22 to the conductive pathways 154 on the interconnect device 120 than the first embodiment.
The overmolding of the non-plated portions provides a mask for the areas to be plated and provides a user-friendly feel to the tab portion 128 of the interconnect device 120 that is to be handled by personnel during use of the assembly 118.
In an alternate embodiment as shown in
While a particular shape has been shown and described for the sensor 22, other shapes may be provided for the sensor 22. The gasket 176 would take on a corresponding shape.
As a result of the construction of the interconnect device 20, 120, the parasitic capacitance is minimal. The bulk of the capacitance results from the connector 24 to which the interconnect device 20, 120 is attached. This capacitance is not transmitted to the sensor 22, such that the capacitance generated by the connector 24 does not effect the sensor 22.
Other components can be easily formed on and added to the interconnect device 20, 120, such as resistor, capacitors, etc., if desired.
While six leads 28 are shown on the sensor 22, six conductive pathways 40, 154 are shown on the interconnect device 20, 120 and six terminals 34 are provided on the connector 24, it is to be understood that more or fewer leads 98, pathways 40, 154 and terminals 34 can be provided. In addition, a plurality of terminals 34 can be provided on the connector 24, with the pathways 40, 154 only contacting predetermined ones of the terminals 34, such that some of the terminals 34 are not used.
The two-shot molding process, which represents one possible way of forming the interconnect device 20, 120, allows for inexpensive manufacturing which is desirable as the assembly 118 is generally utilized as a throw away or disposable device. Also, the two-shot molding processes are amenable to being highly automated which is important, as the potential number of these assemblies 118 could be very high. The design of the assembly 118 can also be produced in a very cost effective manner through the use of parts consolidation and process step elimination.
As a result of the construction of the interconnect device 20, 120, the materials used to form the interconnect device 20, 120 can be opaque. This lessens the degradation of the electrical components than if the materials were transparent.
While preferred embodiments of the present invention are shown and described, it is envisioned that those skilled in the art may devise various modifications of the present invention without departing from the spirit and scope of the appended claims.
This application claims the domestic priority of U.S. provisional application Ser. No. 60/628,586, filed on Nov. 17, 2004, which disclosure is herein incorporated by reference.
Filing Document | Filing Date | Country | Kind | 371c Date |
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PCT/US2005/041655 | 11/17/2005 | WO | 00 | 12/4/2007 |