Patent ID: 12207419

DETAILED DESCRIPTION

The present disclosure provides a low cost sensor and methods of assembly and manufacture of the low cost sensor. In some embodiments, the sensor circuits are configured such that each of the flex circuits for each of the plurality of sensors is tessellated or nested with one another as it is manufactured. In some embodiments, this configuration maximizes the number of circuits that can be manufactured and assembled from a set of materials. Such a configuration further minimizes the amount of material wasted.

The present disclosure also describes a method for assembling an L-shaped sensor or bent sensor from a straight sensor. Previous manufacturing methods for L-shaped sensors created substantial waste as the profile of the L-shaped sensor prevented the flex circuits from being printed in a staggered formation so as to maximize the use of the substrate material. By assembling the L-shaped sensor from a straight sensor, the profile of the flex circuit is minimized and the amount of waste is therefore minimized. The method of folding described below allows a plurality of different sensor shapes to be manufactured from a straight sensor.

FIGS.1-2illustrate various views of the flex circuit100of the sensor assembly.FIGS.1A-1Bshows one embodiment of the flex circuit100of the sensor.FIG.1Ashows a top view of the flex circuit100. The flex circuit100has a detector end110and a connector end120.FIG.1Bshows a bottom view of the flex circuit100and the corresponding detector end110and connector end120. As can be seen, the flex circuit100is generally linear and has a minimal profile that can help to maximize the number of flex circuits that can be printed on substrate material.

In some embodiments, the configuration of the flex circuit100can be configured to maximize the substrate material that is used and to minimize waste.FIG.2Aillustrates a flexible printed circuit panel array200that includes a first row of flexible circuit202that is nested with a second row of flexible circuits204. In some example, the first row of flexible circuits202and the second row of flexible circuits204can be identical.

As illustrated inFIG.2A, the first and second rows of flexible circuits202,204can include a connector end208and a detector end206. In some embodiments the first row of flexible circuits202and the second row of flexible circuits204are configured such that, on one end of the flexible printed circuit panel array200, the connector end208of the first row of flexible circuit202is proximate to the detector end206of the second row of flexible circuit204and on the other end, the connector end208of the second row of flexible circuit202is proximate to the detector end206of the first row of flexible circuit204.

In addition to the nested configuration, each of the flex circuits100has a body portion232that is uniform along its length which can provide for efficient machining. As illustrated inFIG.2, the uniform body portion232allows for a plurality of flex circuits100to be aligned in a row. As well, the straight line of the body portion232requires a single straight-line cut to separate each flex circuit100from the adjacent flex circuit100.

As noted above, the nested configuration of the first and second rows of flexible circuits significantly reduce the waste of the substrate material and increase the speed of production by generating higher yields per substrate sheet. In some examples, the percentage of raw substrate material used to form each of the flexible circuits100is greater than 80% and can be as high as 95% and any percentages in between. In some embodiments, the percentage of waste is as low as 5% to 20% or any percentage there between. In other examples, up to 95% of the material of the flexible printed circuit panel array200can be used to form each of the flex circuits100.

In some embodiments, each of the flex circuits100can be formed from a plurality of layers.FIG.3Aillustrates a perspective view of an exploded flex circuit100that provides a view of the construction of the flex circuit100. In some embodiments, the flex circuit100includes traces216that are printed on a bottom coverlay218. The traces216can include a copper coating while the bottom coverlay218can comprise a polymide material. In some examples, a top panel coverlay214can be layered over the bottom coverlay218that is printed with the traces216. The top panel coverlay can serve as a protective layer over the216. As will be discussed in more detail below, the top panel coverlay can include strategic openings to expose the underlying traces216form electrical connections on the surface of the flex circuit100.

The flex circuit can also include a shielding layer on the top and bottom surface of the flex circuit100to protect the integrity of the traces216and to isolate the traces216from external factors such as radio waves, electromagnetic fields and electrostatic fields. As illustrated inFIG.3A, the flex circuit100can include a top panel shield212that is layered over the top panel coverlay214and a bottom panel shield220that is layered under the bottom coverlay218.

Each of the layers of the above described layers can have a nested configuration so as to form the flexible printed circuit panel array200illustrated inFIG.2. For example,FIG.3Billustrates a sheet comprising a plurality of nested top panel shields212.FIG.3Cillustrates a sheet comprising a top panel coverlay214.FIG.3Dillustrates a “sheet” comprising a plurality of nested traces216.FIG.3Eillustrates a sheet comprising a plurality of nested bottom coverlay218. Lastly,FIG.3Fillustrates a sheet comprising a plurality of nested bottom panel shields220.

The flex circuit100can be configured to be attached to a plurality of components. In some examples, the flex circuit includes a resistor222, an electrically erasable programmable read-only memory (“EEPROM”)224, a detector228, and an emitter226. In some examples, the emitter226can be an LED.

To provide an electrical connection for the plurality of electrical components on the flex circuit100, each of the layers of the flex circuit can include strategic openings to reveal the underlying exposed traces217of the traces216. For example, the top panel coverlay214can include a plurality of windows215and the top panel shield212can include a window213to expose portions of the traces216. The resistor222and EEPROM224can be attached to the flex circuit100at the window213to provide an electrical connection between the resistor222with the exposed traces217and an electrical connection between the EEPROM224and the exposed traces217.

Similarly, as illustrated inFIGS.2and3A, the flex circuit100can include a detector window229and an emitter opening227to accommodate a detector228and emitter226respectively. Turning first to the emitter opening227, the flex circuit100can include a hooked portion to form the emitter window227while maintaining a reduced profile for the flex circuit100. As can be seen inFIG.2, the configuration of the emitter opening227allows each flex circuit100to be nested between adjacent flex circuits to form a tessellated or nested pattern. As discussed above, this can maximize the use of substrate material in the manufacturing of the flex circuit100. The emitter226can be attached to the emitter opening227such that the emitter226can form an electrical connection with the hooked portion of the traces216. As well, the hook configuration provides a circular opening that allows the light produced by the emitter226to be emitted.

FIG.2B-2Cillustrate an enlarged view of the detector end206of the flex circuit100with the attached detector228and emitter226.FIG.2Billustrates a top side of the detector end206of the flex circuit100andFIG.2Cillustrates a bottom side of the detector end206of the flex circuit100. As discussed above, in some embodiments, the emitter opening227is formed from a hook configuration, the end of which is not mechanically coupled to the rest of the flex circuit100. The hook portion of the emitter opening227can include a top portion227a, a first length227band a second length227d. The aforementioned three portions are configured to form an opening227c. The top portion227aand the first length227bform the hook portion that the emitter226can attach to. In some embodiments, the second length227dis longer than the first length227b. As well, in some embodiments, a distance exists between the top portion227aand the second length227d. In some embodiments, to maintain low profile configuration of the flex circuit100, the detector end206of the flex circuit includes an angled portion227eand a length227fthat centers the detector end206along the length of the flex circuit100. As is illustrated inFIG.2C, the first length227band second length227dform an opening227cfor placement of the emitter226. The flex circuit100can then include an angled portion227ethat centers the detector end206of the flex circuit100.

Another aspect of the configuration of the emitter opening227is the ability to bend one portion of the emitter opening227. The configuration of the emitter opening227allows the flex circuit227to be bent at the second length227d, such that a bend exists at the emitter opening227. This can allow the straight flex circuit100to be bent to form a bent or L-shaped flex circuit. As will be discussed in more detail below, the hooked configuration of the emitter opening227provides a mechanical decoupling such that the flex circuit can be easily bent without affecting the attached emitter226.

Turning next to the detector window229, the detector window229can be formed on the surface of the top panel coverlay214to allow light from the light source, such as the emitter226, to transmit through the detector window229and to the detector228. In some embodiments, the detector window229exposes the underlying traces216. The detector228can be attached to the detector window229such that the detector228forms an electrical connection with the traces216.

As will be discussed inFIGS.4A-Ebelow, the detector window229can vary in both shape and configuration so as to provide for varying amounts of light from the light source to enter the detector228. The configuration and structure of each of the grid shapes can allow for the transmission of different amounts of light so as to provide a different function for the flex circuit100.

In some embodiments, the flex circuit100can include a shield flap230. In some embodiments the detector end206of the flex circuit100can form a shield flap230. In some embodiments, the shield flap280can be an etched copper shield made from a copper sheet. The shield flap230of the detector end206can be configured to fold over the detector228to form a Faraday cage. The Faraday cage can provide additional shielding to block external electrostatic fields.

FIGS.4A-4Eillustrate an enlarged view of the various embodiments of the detector window229. The various shield grids are designed to protect the circuits from electromagnetic noise interference while allowing as much light as possible through the grid windows.FIGS.4A-4Eillustrate the first detector window shape410, second detector window420, third detector window shape430, fourth detector window shape440, and fifth detector window shape450respectively.FIG.4Aillustrates the first detector window shape410which is located on the detector end303of the traces416layer of the flex circuit100. The first detector window shield grid shape410includes a shield grid body411with a circular central window412a plurality of arc-shaped window413, and an electrical side contact414on either side of the windows. In the configuration shown in the first detector window shape410, the circular central window412is centered on the bottom portion of the shield grid body411between the pair of side contact414. In this configuration, the first detector window shape410also includes four arc-shaped windows413that are spaced about the circular central window412. In some embodiments, the circular central window412of the first detector window shape410allows a significant portion of light through to the detector while still blocking electromagnetic interference.

FIG.4Billustrates the second detector window shape420which is located on the detector end303of the traces426layer of the flex circuit100. The second detector window shape420includes a shield grid body421with a plurality of narrow rounded rectangular windows422and side contacts424on either side of the plurality of narrow rounded rectangular windows422. In the configuration shown in the second detector window shape420, the narrow rounded rectangular windows422have four narrow rounded rectangular windows422that are located on the shield grid body421between the two side contacts424on either side of the shield grid body421.

FIG.4Cillustrates the third detector window shape430which is located on the detector end303of the traces436layer of the flex circuit100. The third detector window shape430includes a shield grid body431, a central window432, a plurality of rectangular windows433, and side contacts434on either side of the central windows432. In the configuration shown in the third detector window shape430, the plurality of rectangular windows433and the central window432are centered on the bottom portion of the shield grid body431between the two side contacts434. In some embodiments, the two rectangular windows433are located above and below the central window432.

FIG.4Dillustrates the fourth detector window shape440which is located on the detector end303of the traces446of the flex circuit100. The fourth detector window shape440includes a shield grid body441, a central window442, a plurality of narrow rectangular windows443, and a side contact444on either side of the central window442. In the configuration shown in the fourth detector window shape440, the narrow rectangular window443and the central window442are centered on the bottom portion of the shield grid body441between the two side contacts444. In some embodiments, the two narrow rectangular window443are located above and below the central window442.

Lastly,FIG.4Eillustrates the fifth detector window shape450which is located on the detector end303of the traces456of the flex circuit100. The fifth detector window shape450includes a shield grid body451, a central window452, a plurality of side contact454, and a side contact454on either side of the central window452. In the configuration shown in the fifth detector window shape450, the central window452and the plurality of trapezoidal window453are located on the bottom portion of the shield grid body451. In some embodiments, each of the plurality of trapezoidal window453is located one side of the central window452such that the shorter end of the trapezoid is proximate to a side of the central window452.

The configuration of the two sheet flexible printed circuit panel array300provides for a larger number of sensors to be assembled at the same time. Once all of the components have been attached and assembled on each of the sensor assemblies, each of the sensor assemblies644can be sealed in protective material. As illustrated inFIGS.5A-5D, in some embodiments, the sensor assemblies can include top and bottom portions646. For example, in some embodiments the sensor assemblies can covered on both top and bottom with a layer of foam646. The foam covering covers the flex circuit and traces and forms a cable covering which extends from the emitter and detector assemblies to a connector end of the flex circuit. In some embodiments, a top foam646and a bottom foam646can be sealed together to sandwich the flex circuit such that the sensor assembly is entirely covered by the foam.

In some embodiments, each of the sensor assemblies644can include a top head tape636and a bottom head tape636attached to cover each individual sensor. In some embodiments, the top head tape636can be the same size as the bottom head tape636. In some embodiments the top head tape636can have a design such as sensor artwork or logos printed on its top surface. In some embodiments, after the bottom head tape636and the top head tape636have been attached to the sensor assembly, the sensor assembly can be laminated.

Each of the sensor assemblies can further include a bottom and top connector tab. The connector tab provides the sensor assembly644with a structure to allow the sensor644to attach to a connector.FIG.5Aillustrates an example of a sensor assembly644with connector tabs attached. In some embodiments, the bottom connector stiffener656can include a flex circuit mating area658. In some embodiments, the resistor end of the sensor644is placed such that the exposed traces discussed inFIG.2lie on the surface of the proximal tongue657. The flex circuit mating area658can be configured to connect with the top portion of the connector assembly. Prior to the placement of the sensor644on the bottom connector stiffener656, a bonding agent such as glue or epoxy can be applied to the bottom connector stiffener656. Once applied, the sensor644can placed on the bottom connector stiffener656with component side facing upwards. In the embodiment pictured inFIG.5A, the flex circuit mating area658portion of the bottom connector stiffener656is located on either side of the sensor644. Once the sensor644is attached to the bottom connector stiffener656, the top portion of the connector tab is attached to secure the sensor644. In some embodiments, the underside of the top connector stiffener662has a mating area that corresponds to the flex circuit mating area658such that the top connector stiffener662and flex circuit mating area658are secured together. In some embodiments, the top connector stiffener662and flex circuit mating area658are secured using a locking mechanism or a fastener. The top connector stiffener662and the bottom connector stiffener656can be secured together by a press fit, interference fit, a snap fit, etc.FIG.5Billustrates the sensor644with the connector stiffener652assembled onto the connector end of the sensor644.

Finally, the sensor assembly644can optionally include a printed liner and applicator tape.FIGS.5C-5Dillustrate a top perspective view of the sensor644with the added printed liner and the applicator tape.FIG.5Cprovides a top view of the sensor644and a top and perspective view of the sensor644with the printed liner664added. The printed liner664can be printed with a variety of designs and/or colors. As can be seen inFIG.5C, the printed liner664can be long enough to fit the length of the head tape636section of the sensor assembly644.FIG.5Dillustrates a top and perspective view of the sensor assembly644with printed liner664and added applicator tape668. The applicator tape668can have a variety of shapes and sizes. In some embodiments, the688has a length and width that can fit onto the printed liner664.

As described above, another benefit of the present configuration of the flex circuit design is the ability to assemble a bent sensor from the linear flex circuit described above.FIG.6Aillustrates a flowchart that describes an embodiment of a method of sensor folding500.FIGS.6B-6Dillustrate a method of sensor folding800that corresponds with the steps of the flowchart shown inFIG.6. As discussed earlier, althoughFIGS.6A-Ddescribe the formation of an “L-shaped” sensor, the steps described can be applied to fold the flex circuit into a sensor that is bent at an angle greater or less than 90 degrees.

The method of sensor folding500can include block510which describes folding the flex circuit through the centerline of the emitter such that the detector is facing a second direction.FIG.6Billustrates the sensor prior to folding. As seen in previous figures, the sensor644includes a detector640, an emitter650, and a neck630connecting the detector640with the emitter650. As discussed above, the neck630is formed from a second length227d, an angled portion227eand another length227fwhich is configured to maintain the straight configuration of the flex circuit100. As discussed above, the second length227dis initially angled to one side to form the opening227cthat accommodates the emitter226.

In the configuration ofFIG.6B, the detector640and emitter650both face a first direction such that the detector window and emitter opening both face a second direction.FIG.6Cillustrates the sensor644with a first fold610through the centerline of the emitter650. In this embodiment, the first fold610is at a 45 degree angle with the remaining length of the sensor644. In other embodiments, the angle of the first fold610can range from 0-180 degrees. The first fold610creates a fold in the neck emitter opening such that the detector640is facing a second direction, with the detector window facing a first direction.

Once the first fold is made, the method of sensor folding500can further include block520which describes folding the flex circuit a second time such that the two folds—the first fold and the second fold—form a 45 degree angle and the detector is now facing a first direction.FIG.6Dillustrates the second fold620of the L-shaped sensor660. The second fold620and the first fold610form fold angle α. In some embodiments, the fold angle α is at a 45 degree angle. The second fold620also turns the detector640such that it is facing a first direction and the detector window is facing a second direction. In this way, the direction of the detector640and detector window are facing the same directions as they were prior to folding. After folding, a head tape, applicator tape and liner can be added to finish the sensor similar to those described above. Moreover, the folding of the sensor flex circuit can occur at any time during the manufacturing process and is not limited to any particular sequence of sensor construction.

Finally, all of the sensors discussed above can be reprocessed or refurbished. The reprocessing or refurbishing of physiological sensors involves reusing large portions of an existing sensor. The reprocessed or refurbished sensor therefore has material costs that are significantly lower than making an entirely new sensor. In one example, the reprocessing or refurbishing of the sensor can be accomplished by replacing the adhesive portion of the sensor and reusing the sensing components. In other examples, the process for reprocessing or refurbishing sensors involves replacing the sensing components of the sensor. One such example is described in U.S. Pat. No. 8,584,345 entitled “Reprocessing of a physiological sensor,” which is assigned to Masimo Corporation, Irvine, Calif., and incorporated by reference herein.

Although this disclosure has been disclosed in the context of certain preferred embodiments and examples, it will be understood by those skilled in the art that the present disclosure extends beyond the specifically disclosed embodiments to other alternative embodiments and/or uses of the disclosure and obvious modifications and equivalents thereof. In addition, while a number of variations of the disclosure have been shown and described in detail, other modifications, which are within the scope of this disclosure, will be readily apparent to those of skill in the art based upon this disclosure. It is also contemplated that various combinations or sub-combinations of the specific features and aspects of the embodiments may be made and still fall within the scope of the disclosure. Accordingly, it should be understood that various features and aspects of the disclosed embodiments can be combined with or substituted for one another in order to form varying modes of the disclosed.