System and method for controlling the height between a bonding tool and a connection pad

Abstract

The present invention relates to a system and method for controlling the height between a bonding tool and a connection pad. The present invention provides a method for electrically connecting a conductor to a connection pad of a flexible circuit strip using a bonding tool, the method comprising: receiving the flexible circuit strip on a support surface; positioning the bonding tool above a first connection pad of the flexible circuit strip; monitoring a first capacitance between the bonding tool and a conductive layer positioned below the connection pad; controllably lowering the bonding tool toward the first connection pad until the first capacitance reaches a first predefined capacitance threshold, wherein the first predefined capacitance threshold defines a first height of the bonding tool relative to the flexible circuit strip; monitoring a second capacitance between a first electrode electrically connected to the first connection pad and the bonding tool; controllably lowering the bonding tool from the first height until the second capacitance reaches a second predefined capacitance threshold; and activating the bonding tool to electrically connect the first connection pad to the conductor.

Description

Technical Field

[0001] The present disclosure, in some embodiments thereof, relates to catheter manufacturing and, more particularly, but not exclusively, to establishing electrical connections to flexible circuit strips of a catheter. Background Art

[0002] A wide range of medical procedures involve the placement of probes, such as catheters, within a patient's body. Electrode catheters have been common in medical practice for many years. They are used to stimulate and map electrical activity in the heart, as well as to ablate sites of abnormal electrical activity.

[0003] Position sensing systems have been developed to track such probes. Magnetic position sensing is one of the methods known in the art. In magnetic position sensing, magnetic field generators are typically placed at known locations outside the patient's body. Magnetic field sensors within the distal end of the probe generate electrical signals in response to these magnetic fields, which are processed to determine the coordinate position of the distal end of the probe. Impedance or current-based systems can also be used to track position.

[0004] The wall cavity of a patient's organ, such as a cardiac cavity, can be mapped and / or ablated using a catheter having a plurality of electrodes mounted at an expandable distal end assembly of the catheter. The expandable distal end assembly is coupled at the distal end of a catheter shaft for insertion into the cavity. The expandable distal end assembly can be shaped in the form of a balloon, a basket, and / or another type of cage, and can include a plurality of electrodes configured to sense and / or deliver therapeutic signals. BRIEF DESCRIPTION OF THE DRAWINGS

[0005] In order to better understand the subject matter disclosed herein and to illustrate how the subject matter may be implemented in practice, various embodiments will now be described, by way of non-limiting examples only, with reference to the accompanying drawings, in which:

[0006] Figure 1A is a schematic diagram of a basket catheter according to some embodiments of the present disclosure;

[0007] Figure 1B is a simplified schematic diagram of a flexible polymer circuit strip according to some embodiments of the present disclosure;

[0008] Figure 2A is a simplified schematic diagram of a system for providing electrical connections to a flexible circuit strip according to some embodiments of the present disclosure;

[0009] Figure 2B and Figure 2C is a simplified schematic diagram showing the attachment of a connector to a pad according to some embodiments of the present disclosure;

[0010] Figure 2D Wire 244 is shown in position to connect to pad 210a;

[0011] Figure 3 is a method of establishing a connection to a flexible circuit strip according to some embodiments of the present disclosure;

[0012] Figure 4 is a simplified schematic theoretical graph of capacitance over time according to some embodiments of the present disclosure; and

[0013] Figure 5 is a simplified schematic theoretical graph of capacitance over time according to some embodiments of the present disclosure. In some embodiments, although non-limiting, like elements are referred to using like reference numerals. DETAILED DESCRIPTION

[0014] The present disclosure, in some embodiments thereof, relates to catheter manufacturing and, more particularly, but not exclusively, to establishing electrical connections to flexible circuit strips of a catheter.

[0015] Overview

[0016] Some catheters, such as basket catheters, may have about 100 electrodes mounted on a plurality of splines of a basket that is coupled to a connector at the proximal end of the shaft through the shaft of the catheter. The printed circuit board (PCB, also referred to herein as a "flexible circuit strip") on the splines and the PCB of the connector both have pads, and a plurality of wires (e.g., a wire for each electrode) extending through the shaft provide electrical connections. The distal end of each wire is coupled to a predefined pad on the spline, and the proximal end of each wire is coupled to a corresponding pad in the connector to exchange electrical signals between the electrode and a console (e.g., a PIU (patient interface unit) of the catheter) via the shaft. The large number of pads and wires may require the pad size to be reduced to tens of microns. The pad size may be on the order of tens of microns (also referred to herein as microns) for each pad on the printed circuit board, resulting in a time-consuming and expensive connection process between the wires and the corresponding pads.

[0017] Broad aspects of some embodiments of the present disclosure relate to an automated method for soldering or welding a wire to a pad (also referred to herein as a "connection pad") of a flexible circuit strip of a catheter device by automated positioning of a bonding tool. In some embodiments, the flexible circuit strip includes a plurality of pads, wherein electrical connections to each pad are established individually (e.g., sequentially) by bringing a bonding tool to each pad (e.g., contacting each pad). The positioning of the bonding tool (e.g., the height of the tool tip above the pad) can be controlled using a measurement of capacitance at the bonding tool.

[0018] A potential benefit of automation and / or automation using capacitance measurements is the ability to quickly and / or accurately establish connections to small-sized pads that may be densely placed on a small surface area of ​​a flexible circuit strip.

[0019] In some embodiments, the flexible circuit strips and / or pads are delicate (e.g., mechanically delicate), for example, due to their size. The size potentially means that it is difficult to position a bonding tool at the correct height over each pad without damaging the pad and / or the flexible circuit strip, but at the same time the height of the tool over the pad is sufficient so that the bonding performed with the tool forms a reliable connection (e.g., sufficiently conductive and / or mechanically strong).

[0020] A potential benefit of bringing the bonding tool accurately to the pad is a reduced risk of damaging the flexible circuit strip, for example, by applying excessive pressure through the bonding tool. Another potential benefit of bringing the bonding tool accurately to the pad is the ability to form a high-quality (e.g., mechanically strong and / or conductive) connection with the pad, for example, associated with the correct positioning of the bonding tool relative to the pad. Wherein correct positioning includes accurately positioning the tip of the bonding tool at a defined distance (e.g., height above the outer surface) from the outer surface of the pad to be connected. In an embodiment, the desired distance (e.g., height) between the outer surface of the pad and the tip of the bonding tool is on the order of microns.

[0021] An aspect of some embodiments of the present disclosure relates to automatically positioning a bonding tool using a multi-step process and / or multiple different measurements.

[0022] Wherein, optionally, one or more images acquired by a camera (e.g., a visible light camera) are used to bring the bonding tool to the approximate location of the pad. In some embodiments, imaging is used to position the bonding tool approximately perpendicular to the planar surface of the flexible circuit strip, in a height direction above the pad (also referred to herein as the "z" direction), and in a lateral direction (e.g., also referred to herein as the "xy" direction) approximately parallel to the flexible circuit strip (e.g., the planar surface of the flexible circuit strip).

[0023] In some embodiments, for example, after the bonding tool is roughly positioned using an image, capacitance measurements are used to bring the bonding tool into position over, for example, into contact with, the pad.

[0024] In some embodiments, the bonding tool and the flexible circuit strip TogetherA first capacitance is measured between the positioned conductive elements. Wherein, in some embodiments, the conductive element is close to (e.g., within 1 mm) and / or contacts the flexible circuit strip and / or forms a part of the flexible circuit strip, for example, the conductive element is a conductive layer. The pad can be spatially arranged between a bonding tool (e.g., after roughly positioning the bonding tool) and the conductive element, and movement of the bonding tool toward the conductive element reduces the distance (e.g., height) between the pad and the bonding tool. For example, in the case where the conductive element is arranged to extend below the pad, the pad is arranged between the conductive element and a bonding tool that can approach the pad from above. In some embodiments, the conductive element (e.g., a conductive layer) overlaps with an area of ​​the pad, for example, extends below an area of ​​the flexible circuit strip (e.g., a footprint) that accommodates the pad, for example, extends below the entire footprint of the pad.

[0025] Although the description herein is about a bonding tool approaching a solder pad from above, it should be understood that the present disclosure also relates to situations in which the flexible circuit strip is oriented at different positions and / or angles relative to the bonding tool, for example, the flexible circuit strip is disposed above the bonding tool, for example, the bonding tool is moved upward to approach the solder pad.

[0026] In some embodiments, the conductive element extends generally parallel to the pads, e.g., extends beneath the pads. In some embodiments, the conductive element is disposed within the body of the flexible circuit strip. In some embodiments, the conductive element is located beneath the flexible circuit strip, e.g., where the conductive element supports the flexible circuit strip (e.g., is mounted to or is part of a support) and / or where the conductive element is attached to the back side of the flexible circuit strip (the back side of the flexible circuit strip being the surface opposite the top surface of the flexible circuit strip that receives the pads).

[0027] In some embodiments, the flexible circuit strip includes a plurality of pads, each of which is connected to a corresponding electrode by an electrical connector (e.g., a wire and / or a conductive trace, wherein the term wire used in this context should be understood to encompass "conductive trace" or "trace") extending along (e.g., through) the body of the flexible circuit strip. In some embodiments, the pads are disposed at a first portion of the flexible circuit strip (e.g., a proximal end of the flexible circuit strip) and connected to a sensing electrode located at a second portion of the flexible circuit strip (e.g., a distal end of the flexible circuit strip).

[0028] In some embodiments, the conductive element overlaps at least one of the plurality of pads of the flexible circuit strip, or a subset of the plurality of pads, or overlaps all of the pads (e.g., extends under all of the areas that accommodate the pads). In some embodiments, the conductive element may not extend continuously under all of the areas that accommodate the pads, but may extend under each individual pad with a connecting portion between them.

[0029] For example, in embodiments where a conductive element overlaps a subset of the plurality of pads, measurements taken with respect to a first pad that overlaps a conductive element (and / or control signals generated using those measurements) may be used with respect to subsequent pads that do not overlap the conductive element.

[0030] In some embodiments, the conductive element also overlaps (eg, extends underneath) a portion of the flexible circuit strip that houses the electrode. Wherein, in some embodiments, the conductive element extends over the entire footprint of the pad and electrode.

[0031] In some embodiments, the second capacitance is measured between the pad itself (and / or a direct electrical connection to the pad) and the bonding tool. In some embodiments, the direct electrical connection is provided by an electrode of a flexible circuit strip electrically connected to the pad.

[0032] In an exemplary embodiment, a first capacitor is used to move a bonding tool closer to a pad (e.g., closer than can be achieved using imaging), and a second capacitor is used for fine positioning of the bonding tool relative to the pad, e.g., before activating the bonding tool to establish an electrical connection to the pad.

[0033] In some embodiments, the surface of the conductive element opposite the bonding tool has a surface area greater than the surface area of ​​each pad, wherein the larger surface area and / or higher dielectric constant (e.g., compared to air between the bonding tool and the pad) of the material of the flexible circuit strip can provide, for example, a higher capacitance measurement than a second capacitance measurement between the bonding tool and the pad.

[0034] In some embodiments, the pads are disposed at different distances (heights) from the bonding tool. For example, associated with the flexibility of the strip, e.g., the strip does not fully conform to a flat support surface. For example, in some embodiments, the different distances of the bonding tool from the pads can be associated with different topologies of the pads and / or the top surface of the flexible circuit strip. For example, in the case where the flexible circuit strip is mounted to a support structure before establishing an electrical connection to the pads, the support structure (e.g., a Nitinol spline) may not form a planar support for the flexible circuit strip (e.g., the Nitinol spline may have a variable thickness).

[0035] In some embodiments, the pads have a small connection surface and / or are positioned close to each other compared to the size and / or spacing of the electrodes. Contacting of the electrodes for measuring the second capacitance is potentially easier and / or provides better electrical contact for the measurement.

[0036] Before describing in detail at least one embodiment of the present invention, it should be understood that the present invention is not necessarily limited in its application to the details of construction and arrangement of components and / or methods set forth in the following description and / or shown in the drawings and / or examples. The present invention is capable of other embodiments or can be practiced or implemented in various ways.

[0037] Exemplary catheters

[0038] Figure 1A is a schematic diagram of a basket catheter 111 according to some embodiments of the present disclosure.

[0039] The basket catheter 111 includes an elongated deflectable element 112 having a distal end 114, a connector 116 connected to the distal end 114, and an optional push rod 118. The optional push rod 118 is configured to advance and retract through the deflectable element 112, for example using a manipulator or handle (not shown). The basket catheter 111 also includes an expandable component 122, which includes a plurality of flexible circuit strips 124 (for simplicity, only some flexible polymer circuit strips are labeled), also referred to herein as "flexible splines". In some embodiments, the flexible circuit strips 124 are polymer circuit strips. Each flexible circuit strip 124 includes a plurality of electrodes 126 disposed thereon (for simplicity, only some are labeled). The formation of the various elements and how they are connected to each other are described in more detail in U.S. Patent Application Publication No. US2021 / 0187241.

[0040] In some embodiments, the form and / or structure of the basket catheter 111 is provided by a basket structure, which in some embodiments comprises (e.g., is formed of) nitinol, for example, including a plurality of nitinol strips (also referred to herein as "splines"). Wherein at least a portion of the flexible circuit strips 124 are each supported by a corresponding nitinol strip. In some embodiments, the strips of the nitinol basket structure are connected together, for example, at the proximal end of the basket catheter 111. The flexible circuit strips 124 may be formed on a pad (e.g., Figure 1B In some embodiments, before or after the flexible circuit strip is connected to the nitinol support structure, when the flexible circuit strip 124 is in a flat and / or unbroken configuration (e.g., Figure 1B ), an electrical connection to the pad 110 of the flexible circuit strip 124 is established.

[0041] Exemplary Flexible Circuit Strip Implementations

[0042] Figure 1B is used for Figure 1A A top view of the flexible polymer circuit strips 124 of the basket catheter prior to assembly.

[0043] Reference now Figure 1B , this figure is used for Figure 1A Schematic diagram of a flexible polymer circuit strip 124 in a basket catheter 111 of FIG. The flexible polymer circuit strip 124 can be formed from a single piece of polymer such as polyimide. The circuit strips 124 can be connected to each other through the polyimide or assembled to maintain proper alignment and fixation to the Figure 1A The circuit strips 124 are separate pieces of the connector 116. By manufacturing the circuit strips 124 as separate components, the yield of the base circuit can be increased because a faulty electrode causes one circuit strip to fail rather than the entire strip assembly. The respective first end 142 of the respective flexible polymer circuit strip 124 includes an array of electrical connections 160.

[0044] Inset 162 shows that the electrical connection array 160 includes pads 110 thereon (only some are labeled for simplicity). The pads 110 are connected to corresponding electrodes in the electrodes 126 disposed on the front of the flexible circuit strip 124 via conductive wires (not shown) optionally located on the back of the flexible polymer circuit strip 124. Away from the area of ​​the first end 142, the flexible circuit strips 124 are separated from each other to allow the flexible circuit strips 124 to form an expandable assembly 122 ( Figure 1A ). Wires (not shown) may connect electrodes 126 to control circuitry (not shown) via pads 110. Wires may be disposed on elongated deflectable element 112 ( Figure 1A ) in a lumen (not shown).

[0045] The flexible circuit strip 124 can have any suitable dimensions. For example, the length of the flexible circuit strip 124 can be in the range of 10 mm to 60 mm (e.g., 30 mm), the width of the flexible circuit strip 124 can be in the range of 0.25 mm to 3 mm (e.g., 0.72 mm), and the thickness of the flexible circuit strip 124 can be in the range of 0.005 mm to 0.14 mm.

[0046] In some embodiments, the electrodes 126 extend to occupy a majority of the width of the flexible circuit strip 124 that accommodates them. In some embodiments, the electrode width 192 is 0.25 mm to 3 mm, and / or the electrode length is 0.25 mm to 3 mm.

[0047] In some embodiments, one or more pads are smaller than the electrode size. Wherein the pad presents a surface area that is smaller than the electrode for contact (e.g., by a measuring probe or bonding tool). For example, the pad upper surface area is 1% to 20% of the electrode surface area. For example, the pad width 194 is 0.05 mm to 0.5 mm, and / or the pad length 196 is 0.1 mm to 1 mm.

[0048] The surface area 162 of the flexible circuit strip 124 on which the pads 142 are disposed can be small and / or the density of the pads on that area can be high, for example, an area having a width 178 of 0.25 mm to 3 mm and a length 198 of 0.5 mm to 6 mm and / or the proportion of the surface area occupied by the pads is 20% to 50%.

[0049] Exemplary Electrical Connection Systems

[0050] Figure 2A is a simplified schematic diagram of a system 200 for providing electrical connections to a flexible circuit strip 124 according to some embodiments of the present disclosure.

[0051] In some embodiments, the flexible circuit strip 124 is part of a catheter, for example having a Figure 1A One or more features shown and / or described for the catheter 111. Wherein, in some embodiments, the flexible circuit strip 124 corresponds to Figure 1A and / or Figure 1B One or more (eg, each) of the flexible circuit strips 124 .

[0052] In some embodiments, the system 200 includes a bonding tool 216 configured to bond an electrical connector (e.g., a wire (not shown)) to the pads 110 (e.g., one pad at a time). In some embodiments, the bonding tool 216 is a thermal bonding tool, such as a soldering iron, or a welding gun, or an ultrasonic bonding tool.

[0053] In some embodiments, system 200 includes support 215 that provides mechanical support to flexible circuit strip 124. For example, support 215 holds flexible circuit strip 124 in place, potentially enabling bonding tool 216 to apply pressure to pads, for example, during a bonding process. In some embodiments, support 215 is rigid.

[0054] In some embodiments, system 200 includes one or more sensors 208, 220, 222, wherein one or more of sensors 208, 220, 222 are capacitive sensors.

[0055] exist Figure 2A In some embodiments, electrical connections (eg, for capacitance measurements) are shown by solid lines and data connections are shown by dashed arrows.

[0056] In some embodiments, the flexible circuit strip 124 has at least one (e.g., multiple) electrodes 126. The electrodes 126 may be disposed on the distal portion 206 of the flexible circuit strip 124. The electrodes 126 may be disposed on the outer surface of the flexible circuit strip 124, for example, one or more of the electrodes 126 may protrude from the substantially flat outer surface (e.g., the top surface) of the flexible circuit strip 124, and / or one or more of the electrodes 126 may have an electrode top surface that is flush with (or recessed from) the top surface of the flexible circuit strip 124.

[0057] In some embodiments, a plurality of pads 110 are disposed on a first (e.g., proximal) portion 228 of the flexible circuit strip 124, and a plurality of electrodes 126 are disposed on a second (e.g., distal) portion 206 of the flexible circuit strip 124. In some embodiments, one or more (e.g., each) of the electrodes 126 are electrically connected to a corresponding pad in the plurality of pads 110, e.g., each electrode is electrically connected to the pad by a separate wire. In some embodiments, the electrical connections (e.g., wires) extend through the body of the flexible circuit strip 124, e.g., wherein the plurality of pads 110 are electrically connected to the plurality of pads 110. Figure 2A , a single such electrical connection wire 212 is shown connecting a particular electrode 126a to a particular pad 210a.

[0058] In some embodiments, the flexible circuit strip 124 includes multiple layers, wherein, for example, wires connecting the pads 110 to the electrodes 126 are sandwiched between at least two layers. Among them, in some embodiments, the outer surface 252 (also referred to herein as the "top surface" 252) of the flexible circuit strip 124 accommodates the pads 110 and the electrodes 126. In some embodiments, the top surface 252 includes an electrically insulating material (e.g., portions other than the pads or electrodes are formed of a polymer).

[0059] In some embodiments, the flexible circuit strip 124 includes a conductive element 214 that extends under (e.g., substantially parallel to) one or more of the plurality of pads 110, such as extending to each of the pads 110 or to a subset of the pads 110. In some embodiments, the conductive element 214 extends under at least one of the plurality of pads 110. In some embodiments, the conductive element 214 extends under all of the plurality of pads 110. In some embodiments, the conductive element extends under at least one pad and at least one electrode. In some embodiments, the conductive element 214 extends under one or both of the plurality of electrodes 126 and the plurality of pads 110. In an exemplary embodiment, the conductive element 214 extends under each of the plurality of electrodes 126 and each of the plurality of pads 110.

[0060] In some embodiments, the conductive element 214 extends beneath multiple pads 110 (and optionally electrodes 126), where the shortest distance measured between each pad (and optionally electrodes) and the conductive element is the same, e.g., where the distance has a variation of at most 5% (e.g., determined as a percentage of an average of the distances measured between the pads (and optionally electrodes) and the conductive element).

[0061] In some embodiments, the conductive element 214 extends along the flexible circuit strip 124, and in some embodiments, is generally parallel to the top surface 252 and / or the bottom surface 254. In some embodiments, the conductive element 214 extends laterally (e.g., perpendicular to the elongation direction of the elongated flexible circuit strip 124) across at least a majority of the width 192 of the flexible circuit strip (e.g., as shown in FIG. 1 ). Figure 2A as shown, across at least 80% or all thereof).

[0062] In some embodiments, the conductive element 214 is a layer of a layered structure of the flexible circuit strip 124. In some embodiments, an insulating layer separates the conductive element 214, the pad 110, and the electrode 126. Optionally, for example, Figure 2A As shown, the conductive element 214 is an inner layer of the flexible circuit strip 124, wherein a layer 256 (e.g., electrically insulating) is disposed between the conductive element 214 and a bottom surface 254 of the flexible circuit strip 124. The bottom surface 254 of the flexible circuit strip 124 is a generally flat surface opposite the top surface. Alternatively, in some embodiments, the conductive element 214 forms at least a portion of the bottom surface of the flexible circuit strip 124, e.g., the layer 256 is not present.

[0063] Alternatively or additionally (eg, to conductive element 214), in some embodiments, support 215 comprises a conductive material and provides a conductive element that extends beneath electrode 126 and / or pad 110 (eg, in contact with a bottom surface of the flexible circuit strip).

[0064] In some embodiments, the bonding tool 216 can be automatically moved relative to the flexible circuit strip 124 (e.g., by one or more actuators) to move the bonding tool between the positions of the plurality of pads. In some embodiments, the relative movement of the bonding tool and the flexible circuit strip is in three directions. These directions include, for example, a direction roughly perpendicular to the surfaces 252, 254 (also referred to as the "z direction") and / or a lateral distance roughly parallel to the surfaces 252, 254 (also referred to herein as "xy direction" movement). In some embodiments, the minimum distance between the bonding tool (e.g., the bonding tool tip) and the pad refers to using these two directions, where the "height" is measured as the shortest distance between the bonding tool and the outer surface of the pad in the z direction, and where the "lateral distance" is measured as the shortest distance between the bonding tool and the center of the outer surface of the pad and / or the outer edge of the pad in the xy direction.

[0065] In some embodiments, the bonding tool 216 is mounted on the robot arm 232 and / or as a part thereof (e.g., as an end effector). The actuator of the robot arm is configured to move the bonding tool 216 in one or more dimensions. Alternatively, in some embodiments, the bonding tool 216 is mounted on the stage 232 and / or as a part thereof, and the stage is configured to move the bonding tool in one or more directions. In some embodiments, the support 215 is a part of the stage and / or is held by the stage, and the stage is configured to move the flexible circuit strip relative to the bonding tool in one or more directions. In some embodiments, the bonding tool stage 232 is a z stage, which is configured to move the bonding tool in the z direction, such as controlling the height of the bonding tool above the pad. In some embodiments, the support stage is an xy stage, which is configured to move the support 215 (and the flexible circuit strip) in the xy plane (laterally). The movement of the bonding tool and the support 215 can be simultaneous or sequential. In some embodiments, the robot arm / stage 232 and / or support stage are configured for precise positioning, for example, capable of controlling the position within a micrometer range, such as within 1 μm to 500 μm.

[0066] In some embodiments, the position of the bonding tool (e.g., controlled by a robotic arm and / or stage) is controlled by a controller 218 that receives sensor signals (also referred to herein as "measurement signals" and / or "measurements") from one or more sensors. For example, from one or more of the capacitive sensors 220, 222, 208. The controller may also receive images from one or more cameras 226. The controller may, for example, determine the position of the bonding tool based on the received images and / or capacitive measurements (e.g., Figure 3 Neutral and / or about Figure 3) to generate and / or send control signals (e.g., to one or more stages and / or robotic arms) for movement of the bonding tool 216 and / or the flexible circuit strip 124 (e.g., specifically movement of the tip 228 of the bonding tool). In some embodiments, the controller 218 generates control signals for timing and / or controlling activation of the bonding tool 216, for example based on the received images and / or capacitance measurements. Wherein, in some embodiments (e.g., where the bonding tool includes a soldering iron and / or a welding gun), the activation includes heating the bonding tool, for example, where the control signal may include a duration of heating of the bonding tool and / or a power to drive the heating of the bonding tool and / or a desired temperature of the tool. In some embodiments, the system 200 includes one or more temperature sensors (not shown), for example, the bonding tool may include a temperature sensor that optionally can provide a temperature feedback measurement to the controller 218 to control the temperature of the bonding tool.

[0067] In some embodiments, the bonding tool tip 238 includes an outer surface, such as a covering including a highly electrically conductive and / or thermally conductive and / or heat resistant material. For example, the bonding tool includes a covering configured to cover (e.g., surround) at least a portion of the bonding tool 216 between the electrical contact area between the capacitive sensors 208, 220 and the bonding tool 216. In some embodiments, the resistive and / or capacitive properties of the bonding tool (e.g., as associated with high electrical and / or thermal conductivity) have a low dependence on temperature.

[0068] In some embodiments, at least a portion of the bonding tool (e.g., tip 238 and / or a portion of the tip) that contacts the pad during establishment of the connection to the pad is non-adhesive to the material of the pad 110. For example, at the temperature employed during establishment of the connection to the pad. When the bonding tool is a soldering iron, the material of the bonding tool that contacts the solder may be non-adhesive to the solder, for example, alternatively or additionally to the pad surface.

[0069] In some embodiments, the bonding tool tip and / or the cover of the bonding tool and / or regions in the electrical path between the bonding tool and sensors 208 , 220 include (eg, are formed of) gold.

[0070] Figure 2B to Figure 2C is a simplified schematic diagram showing the attachment of connector 244 to pad 210a according to some embodiments of the present disclosure.

[0071] Wherein, in some embodiments, Figure 2B The bonding tool tip 238 is shown approaching the pad 210a. In some embodiments, Figure 2CThe contact between pad 210a, wire 244 and tip 238 is shown. In some embodiments, Figure 2D Wire 244 is shown in position to connect to pad 210a.

[0072] When the bonding tool 216 includes a soldering iron, the contact can be additionally or alternatively between the bonding tool and the solder. The solder can be supplied by the bonding tool itself (e.g., the bonding tool 216 supplies the solder to the tip 228). Alternatively or in addition, the wire 244 can include solder and / or the pad 210a can include solder, wherein the proximity of the tip 228 can melt the connector and / or pad solder to connect the connector to the pad.

[0073] In some embodiments, the wire 244 is manually and / or automatically positioned at the pad 210a.

[0074] For example, in the automatic positioning of the wire 244, the wire 244 can be positioned at the pad 210a by one or more actuators 246. Optionally, the controller 218 controls the position of the wire 244 to be connected to the pad, for example, via the actuator 246.

[0075] For example, in some embodiments, the conductors 244 (e.g., one conductor per pad) are positioned (e.g., with the flexible circuit strip 124). For example, by adhering the conductors to the support 215. For example, by coupling the conductors 244 to a clamp 246 that is configured to hold the conductors 224 and the optional flexible circuit strip in place relative to each other (e.g., the clamp includes attachment and / or positioning means between the support 215 and the conductors 224).

[0076] Alternatively, in some embodiments, the bonding tool 216 itself positions the wire 244 to connect it to the pad 210a. For example, the stage and / or the robot 232 can be configured to position both the bonding tool and the wire. Wherein, in some embodiments, the wires for different pads can be fed to the bonding tool, for example, sequentially.

[0077] Now back to Figure 2C In some embodiments, the system 200 includes a data connection 240 between the controller 218 and the actuator 232. Data can flow in both directions. For example, in some embodiments, the actuator signal and / or the actuator sensor provide feedback to the controller 218.

[0078] In some embodiments, first capacitance is measured between conductive element 214 and bonding tool 216. For example, capacitance sensor 222 is configured to measure capacitance between conductive element 214 and bonding tool 216 (eg, tip 238 of bonding tool 216).

[0079] In some embodiments, a second capacitance between the flexible circuit strip electrode 126a and the bonding tool 216 (e.g., the bonding tool tip 238) is measured, for example, by the sensor 220. In some embodiments, the electrode is connected to measure by contacting the probe 242 to the electrode, for example, as Figure 2A shown.

[0080] In some embodiments, alternatively or additionally, a second capacitance is measured between circuitry connected to the electrodes and / or pads (eg, at connector 212 ) and bonding tool 216 , for example, by sensor 208 .

[0081] In some embodiments, user instructions are received and / or information is forwarded to the user via one or more user interfaces (UIs) 236. In some embodiments, data is transmitted between the UI 236 and the controller 218. For example, in some embodiments, user instructions are transmitted by the UI 236 to the controller 218, which in some embodiments controls the operation of the system 200 based on the user instructions. One or more UIs may be located locally at the bonding tool 216 and / or other system components, and / or one or more UIs may be located remotely.

[0082] Optionally, in some embodiments, external processing and / or memory circuitry 234 is in communication with UI 236 and / or controller 218. For example, circuitry 234 enables remote control of system 200, such as via a remote UI.

[0083] Exemplary Electrical Connection Methods

[0084] Figure 3 A method of establishing a connection to a flexible circuit strip according to some embodiments of the present disclosure.

[0085] At 300, optionally, in some embodiments, one or more images are acquired, wherein, in some embodiments, the images are processed to identify pads, select pads, and determine the locations of the selected pads (eg, relative to a bonding tool).

[0086] The image may be processed to determine a spatial relationship between a bonding tool and a pad, for example, where both the bonding tool and the pad appear in the acquired image.

[0087] Alternatively or additionally, the image may be processed to determine a spatial relationship between the camera and the selected pad, a known spatial relationship between the camera and the bonding tool, for example, to determine a spatial relationship between the bonding tool and the pad.

[0088] At 302, optionally, in some embodiments, based on the spatial relationship determined using the image at step 300, the bonding tool is positioned at the approximate location of the pad (at which the bonding tool and / or pad is moved), for example, using an XY stage to adjust the positioning of one or more of the bonding tool and the support surface on which the flexible circuit strip is disposed.

[0089] In some embodiments, the movement of the bonding tool toward the selected pad (and / or vice versa) is in more than one direction, for example, wherein the bonding tool moves laterally and in height over the flexible circuit strip and / or pad. The movement in different directions can be simultaneous or sequential.

[0090] In some embodiments, the image is used to position the bonding tool within a lateral distance of, for example, 1 mm to 50 mm, or 1 mm to 20 mm, or 2 mm to 10 mm, or about 5 mm from the center and / or outer edge of the pad.

[0091] In some embodiments, the image is used to position the bonding tool above the pad within a height of, for example, 1 mm to 50 mm, or 1 mm to 20 mm, or 2 mm to 10 mm, or about 5 mm.

[0092] Wherein based on the determined spatial relationship, (e.g., by controller 218) can be instructed (e.g., by moving support 215) the actuator of the stage and / or the robotic arm to position the bonding tool and / or the flexible circuit strip. In some embodiments, steps 300 and 302 occur at least partially within the same time period. For example, in the case where an image is acquired during movement of the bonding tool, the image is used to provide feedback for controlling the movement of the bonding tool.

[0093] In some embodiments, the bonding tool is positioned in a final xy position during this step. Wherein subsequent positioning steps (eg, 306, 310) may cause the bonding tool to move only in the z direction.

[0094] At 304, in some embodiments, a first capacitance is measured between a bonding tool and a conductive element extending parallel to the selected pad and / or an electrode associated with the selected pad. Figure 2A , a first capacitance is measured between bonding tool 216 (eg, at tip 238 of bonding tool 216 ) and conductive element 214 .

[0095] Wherein, in some embodiments, a capacitive sensor (e.g., Figure 2A A capacitance sensor 222) applies a drive signal between the pad bonding tool and the conductive element to obtain a first capacitance measurement.

[0096] At 306, in some embodiments, the height of the bonding tool over the pad (and / or flex circuit strip) is reduced using the first capacitance measurement. For example, until the height from the pad is within 0.5 mm to 20 mm, or 1 mm to 10 mm, or 2 mm to 10 mm. Wherein, in some embodiments, the height of the bonding tool is reduced to a first height over the pad using the first capacitance.

[0097] In some embodiments, steps 304 and 306 occur simultaneously and / or alternately, with the measurement of the first capacitance providing feedback about the distance. In some embodiments, the movement is in a single direction, such as only in height.

[0098] In some embodiments, the height distance between the bonding tools is reduced until a threshold height is reached, for example, as determined by the first capacitance reaching a threshold value (for example, as determined with respect to Figure 4 In some embodiments, the height of the bonding tool is reduced to a second height above the pad using a second capacitor, the second height being less than the first height.

[0099] At 308, in some embodiments, a second capacitance is measured between a particular selected pad and the bonding tool. For example, the capacitance therebetween is measured by a capacitance sensor 208 contacting the pad 210a and the bonding tool tip 238. For example, by measuring the capacitance between the bonding tool and a portion of the flexible circuit strip that is directly electrically connected to the selected pad, such as measuring the capacitance between an electrode associated with the selected pad and the bonding tool (e.g., by a capacitance sensor 220 contacting the electrode 126a and the bonding tool tip 238). The second capacitance may additionally or alternatively be measured between a wire 212 extending between the pad 210a and the electrode 126a (not shown).

[0100] At 310, in some embodiments, the second capacitance measurement is used to reduce the height distance between the bonding tool and the pad, for example, to between 5 μm and 0.5 mm, or 10 μm and 200 μm, or 10 μm and 40 μm.

[0101] In some embodiments, steps 310 and 312 occur simultaneously and / or alternately, and the measurement of the second capacitance provides feedback regarding the distance.

[0102] In some embodiments, the bonding tool is moved toward the selected pad until a threshold distance away from the pad is reached, e.g., as determined by a second capacitance reaching a threshold value (which may be a predefined threshold value) and / or a capacitance peak being identified in the second capacitance measurement, e.g., as determined with respect to Figure 5 as described.

[0103] Alternatively or in addition thereto, in some embodiments, the bonding tool moves toward the selected pad until the contact between the pad and the bonding tool is identified. For example, until contact is identified in the second capacitance measurement, for example, as a decline in the capacitance measured in association with the bonding tool being electrically connected to the pad (short circuit). Optionally, in some embodiments, in addition to the second capacitance, the first capacitance is also monitored during this step. For example, the first capacitance is used to verify the measurement of the second capacitance.

[0104] At 312, in some embodiments, once the distance between the bonding tool and the pad is sufficiently low and / or contact between the bonding tool and the tool is identified, the bonding tool is activated to bond the wire to the pad, e.g., via a thermal bonding technique (e.g., where activation includes activating a heating element, such as supplying power to the heating element). For example, via one or more of welding, fusion welding, and ultrasonic bonding.

[0105] Optionally, in some embodiments, the first capacitance and / or the second capacitance are monitored during activation of the bonding tool. For example, to provide feedback about the connection quality and / or temperature. Wherein, for example, if a low-quality connection is identified, one or more parameters (e.g., the relative position of the bonding tool, e.g., activation parameters of the bonding tool) can be adjusted. Wherein, for example, the activation parameters (e.g., the power supplied to the heating element of the bonding tool, the duration of the supplied power) can be adjusted based on the capacitance measurement feedback about the temperature.

[0106] At 314 , optionally, in some embodiments, the bonding tool is lifted from the selected pad.

[0107] In some embodiments, the method is then repeated for additional pads and / or flex circuit strips.

[0108] For example, starting at step 300, where additional pads may be selected and identified, such as optionally by acquiring additional images to reposition a bonding tool at the approximate location of the additional pads.

[0109] For example, starting from step 306, for example, where steps 300 and 302 are performed less than once per pad connection, for example, where an image is used to position a bonding tool at the approximate location of the pads of the flexible circuit strip, for example, steps 300 and 302 are performed once per flexible circuit strip.

[0110] Figure 4 is a simplified schematic theoretical graph of capacitance C1 over time according to some embodiments of the present disclosure.

[0111] In some embodiments, Figure 4 A first capacitance C1 is shown, for example, measured between the conductive element 214 (or 215) and the bonding tool 238.

[0112] In some embodiments, when the bonding tool is brought closer to the pad, it is also brought closer to the conductive element, thereby potentially increasing the first capacitance measured therebetween, for example, as shown by the increase in capacitance over time at segment 400 of the graph. In some embodiments, once the bonding tool is positioned sufficiently close to the pad, control of movement of the bonding tool is switched to measurement via a second capacitance at time 402. Wherein, in some embodiments, reaching the approximate position is identified as the first capacitance reaching a threshold value 406.

[0113] Figure 5 is a simplified schematic theoretical graph of capacitance C2 over time according to some embodiments of the present disclosure.

[0114] In some embodiments, Figure 5 A second capacitance C2 is shown, for example, measured between pad 210a (or electrode 242) and bonding tool 238.

[0115] Wherein, in some embodiments, as the bonding tool moves toward the pad, the capacitance measured therebetween (directly and / or as measured between the bonding tool and an electrode connected to the pad) increases 500. Wherein, in some embodiments, time 502 corresponds to Figure 4 In some embodiments, sufficient proximity to the pad is determined when the second capacitance reaches a threshold 506 and / or when a peak 501 is identified.

[0116] In some embodiments, contact between a bonding tool and a pad is identified by, for example, a decrease in capacitance 504 and / or a low measured capacitance 508 measured in association with an electrical short of a capacitor formed by the bonding tool and the pad. For example, a short circuit occurs when the bonding tool makes electrical (e.g., and physical) contact with the pad. In some embodiments, the level of capacitance 508 measured after contact is used to verify the quality of the electrical and / or mechanical contact between the bonding tool and the pad, for example, prior to activation of the bonding tool.

[0117] It should be noted that Figure 4 and Figure 5 are theoretical illustrative graphs of expected measurements, and the present disclosure should not be construed as being dependent on the theory and / or details of the illustrative graphs.

[0118] General

[0119] As used within this document, the term "about" means ±20%. The terms "comprising", "including", "containing", "having", "having" and variations thereof mean "including but not limited to". The term "consisting of" means "including and limited to".

[0120] As used herein, singular forms such as "a," "an," and "the" include plural referents unless the context clearly dictates otherwise.

[0121] In the present application, various quantifications and / or expressions may include the use of ranges. The range format should not be interpreted as an inflexible limitation to the scope of the present disclosure. Therefore, the description including the range should be deemed to have all possible sub-ranges clearly disclosed and each numerical value within the range. For example, the description of a range such as 1 to 6 should be deemed to have sub-ranges clearly disclosed such as 1 to 3, 1 to 4, 1 to 5, 2 to 4, 2 to 6, 3 to 6, etc., and each numerical value within the stated range and / or sub-range, such as 1, 2, 3, 4, 5 and 6. Whenever a numerical range is indicated in this document, it refers to any enumerated numerals (fractions or integers) included within the indicated range.

[0122] It should be understood that, for clarity, certain features described in the context of separate embodiments may also be provided in combination in a single embodiment. Various features of the present disclosure described in the context of a single embodiment (e.g., for simplicity) may also be provided separately or in any suitable subcombination, or may be suitable for use with any other described embodiment. Features described in the context of various embodiments should not be considered essential features of those embodiments, unless the embodiment does not function without those elements.

[0123] Although the present disclosure has been described in conjunction with its specific embodiments, it is apparent that many alternatives, modifications and variations are apparent to those skilled in the art. Therefore, this application is intended to cover all such alternatives, modifications and variations that fall within the spirit and broad scope of the appended claims.

[0124] The citation or identification of any reference in this application should not be construed as admitting that such reference can be used as the prior art of the present disclosure. In addition, any priority document and / or document related to this application (e.g., document submitted jointly) are hereby incorporated herein in their entirety by reference.

[0125] When section headings are used in this document, they should not be construed as necessarily limiting.

[0126] General Description

[0127] The following is a non-exclusive list of some exemplary embodiments of the present disclosure. The present disclosure also includes embodiments that include less than all of the features of the embodiments and embodiments that use features from multiple embodiments, even if not listed below.

[0128] Embodiment 1. A method of electrically connecting a wire (244) to a connection pad (110) of a flexible circuit strip (124) using a bonding tool (216), the method comprising:

[0129] The flexible circuit strip (124) is received on a support surface (215), wherein the flexible circuit strip (124) includes a plurality of electrodes (126), a plurality of connection pads (110), and conductive traces (212) connecting each of the plurality of electrodes (124) to a conductive surface (212).

[0130] connected to a connection pad among the plurality of connection pads (110);

[0131] Positioning a bonding tool (216) over a first connection pad (110a) of the flexible circuit strip (124);

[0132] monitoring a first capacitance between the bonding tool (216) and a conductive layer (214) positioned below the connection pads (110), wherein the conductive layer (214) is sized, shaped, and positioned to extend over an entire footprint of the plurality of connection pads (110);

[0133] controllably lowering the bonding tool (216) toward the first connection pad (210a) until a first capacitance reaches a first predefined capacitance threshold, wherein the first predefined capacitance threshold defines a first height of the bonding tool (216) relative to the flexible circuit strip (124);

[0134] monitoring a second capacitance between a first electrode (126a) electrically connected to the first connection pad (210a) and the bonding tool (216);

[0135] causing the bonding tool (216) to controllably lower from the first height until the second capacitance reaches a second predefined capacitance threshold, wherein the second predefined capacitance threshold defines a second height of the bonding tool (216) relative to the first connection pad (210a);

[0136] as well as

[0137] The bonding tool (216) is activated to electrically connect the first connection pad (210a) to the conductive line (244).

[0138] Embodiment 2. The method of embodiment 1, wherein the first height is less than the second height.

[0139] Embodiment 3. A method according to any one of embodiments 1 to 2, wherein the conductive layer (214) is integrated into the flexible circuit strip, wherein the plurality of electrodes (126) and the plurality of connecting pads (110) are disposed on an outer surface (252) of the flexible circuit strip (124).

[0140] Embodiment 4. The method of any one of embodiments 1 to 3, wherein the conductive layer (214) is an inner layer and the flexible circuit strip (124) includes at least another layer (256) disposed between the conductive layer (214) and the support surface (215).

[0141] Embodiment 5. The method according to any one of embodiments 1 to 4, wherein the conductive layer (214) is a conductive sheet or film mounted on the support surface (215) and disposed below the flexible circuit strip (124).

[0142] Embodiment 6. The method of Embodiment 1, wherein the support surface is a surface of a support structure comprising a conductive material forming the conductive layer.

[0143] Embodiment 7. The method of any one of embodiments 1 to 6, wherein the first height and the second height are heights above a top surface (252) of the flexible circuit strip (124) measured in a direction generally away from the top surface.

[0144] Embodiment 8. The method of any one of embodiments 1 to 7, comprising, before controllably lowering the bonding tool toward the first connection pad:

[0145] receiving one or more images of the flexible circuit strip (124); and

[0146] An XY positioning of the bonding tool relative to the first connection pad is controllably adjusted based on the received one or more images.

[0147] Embodiment 9. The method of any one of embodiments 1 to 8, comprising controllably lowering the bonding tool (216) until a tip (238) of the bonding tool contacts the first connection pad (210a).

[0148] Embodiment 10. A method according to embodiment 9, wherein controllably lowering the bonding tool (216) until the tip (238) of the bonding tool contacts the first connection pad (210a) includes identifying contact between the bonding tool (216) and the first connection pad (210a) as a reduction in the second capacitance.

[0149] Embodiment 11. The method of any one of embodiments 9 to 10, comprising using the second capacitance to assess the quality of the contact.

[0150] Embodiment 12. The method according to embodiment 11, comprising, for an additional connection pad of the plurality of connection pads (110):

[0151] Repeating controllably lowering the bonding tool (216) toward the first connection pad until the first capacitance reaches the first predefined capacitance threshold; and

[0152] monitoring a third capacitance between an additional electrode electrically connected to the additional connection pad and the bonding tool (216);

[0153] The bonding tool (216) is controllably lowered from the first height to the first

[0154] The second capacitance reaches the second predefined capacitance threshold; and

[0155] The bonding tool (216) is activated to electrically connect the additional connection pads.

[0156] Embodiment 13. The method of any one of Embodiments 1 to 12, wherein the activating comprises activating circuitry configured to heat the bonding tool.

[0157] Embodiment 14. The method according to any one of embodiments 1 to 13, wherein the bonding tool (216) is a soldering iron or a welding gun or an ultrasonic bonding tool.

[0158] Embodiment 15. The method of any one of embodiments 1 to 14, wherein the first height is less than 100 μm.

[0159] Embodiment 16. The method of any one of embodiments 1 to 15, wherein the second height is less than 20 μm.

[0160] Embodiment 17. The method of any one of embodiments 1 to 16, wherein the bonding tool (216) comprises a cover comprising a heat-resistant and electrically conductive material.

[0161] Embodiment 18. The method of Embodiment 17, wherein the cover comprises gold.

[0162] Embodiment 19. A controller (218) for controlling electrical connection of a wire (244) to a connection pad (110) of a flexible circuit strip (124) using a bonding tool (216) movable by one or more actuators (232), wherein the flexible circuit strip (124) comprises a plurality of electrodes (126), a plurality of connection pads (110), and a conductive trace (212) connecting each of the plurality of electrodes (126) to a connection pad of the plurality of connection pads (110), the controller (218) comprising a circuit system configured to:

[0163] instructing the one or more actuators (232) to position the bonding tool (216)

[0164] on a first connection pad among the plurality of connection pads (110);

[0165] receiving a measurement of a first capacitance between the bonding tool (216) and a conductive layer (214) positioned below the connection pads (110), wherein the conductive layer (214) is sized, shaped, and positioned to be within the overall footprint of the plurality of connection pads (110);

[0166] Upward extension;

[0167] instructing the one or more actuators (232) to lower the bonding tool (216) toward the first connection pad (210a) until the first capacitance reaches a first predefined capacitance threshold, wherein the first predefined capacitance threshold defines the bonding tool (216) relative to the first connection pad

[0168] at a first height of the flexible circuit strip (124);

[0169] Receiving an electrode (126a) electrically connected to the first connection pad (210a) and the

[0170] measuring a second capacitance between the bonding tools (216);

[0171] instructing the one or more actuators (232) to lower the bonding tool (216) from the first height until the second capacitance reaches a second predefined capacitance threshold, wherein the second predefined capacitance threshold defines a second height of the bonding tool relative to the first connection pad (210a); and

[0172] The bonding tool (216) is instructed to activate to electrically connect the pad (210a) to the wire (244).

[0173] Embodiment 20. The controller of embodiment 19, wherein the controller (218) is configured to generate a drive signal for measurement of the first capacitance and for measurement of the second capacitance.

[0174] Embodiment 21. A system (200) for connecting a conductor (244) to a connection pad (110) of a flexible circuit strip (124), the system comprising a plurality of electrodes (126), a plurality of connection pads (110), and a conductive trace (212) connecting each electrode of the plurality of electrodes (126) to a connection pad of the plurality of connection pads (110), the system comprising:

[0175] A joining tool (216);

[0176] one or more actuators (232) configured to control a height between the bonding tool (216) and a flexible circuit strip support (215) configured to receive the flexible circuit strip (124);

[0177] One or more capacitive sensors (208, 220, 222), the one or more capacitive sensors being configured to:

[0178] measuring a first capacitance between the bonding tool (216) and a conductive layer (214) positioned below the connection pads (110), wherein the conductive layer (214) is sized, shaped, and positioned to extend over an entire footprint of the plurality of connection pads (110); and

[0179] measuring a second capacitance between the bonding tool (216) and a first electrode (126a) electrically connected to the first connection pad (210a);

[0180] one or more electrical connectors configured to electrically connect the one or more capacitive sensors to the bonding tool, the conductive layer, and the first electrode;

[0181] A controller (218), the controller being configured to:

[0182] instructing the one or more actuators (232) to move the bonding tool (216)

[0183] Positioning above a first connection pad (210a) among the plurality of connection pads (110);

[0184] receiving a measurement of a first capacitance between the bonding tool (216) and a conductive layer (214) proximate to or as a portion of the flexible circuit strip (124), wherein the plurality of connection pads (110) are disposed between the conductive element (214) and the bonding tool (216);

[0185] instructing the one or more actuators (232) to cause the bonding tool (216) to

[0186] lowering toward the first connection pad until the first capacitance reaches a first predefined capacitance threshold, wherein the first predefined capacitance threshold defines the bonding tool (216)

[0187] a first height relative to the flexible circuit strip;

[0188] receiving a measurement of a second capacitance between an electrode (126a) electrically connected to the first connection pad (210a) and the bonding tool (216);

[0189] instructing the one or more actuators (232) to cause the bonding tool (216) to

[0190] decreasing from the first height until the second capacitance reaches a second predefined capacitance threshold, wherein the second predefined capacitance threshold defines a second height of the bonding tool (216) relative to the first connection pad (210a); and

[0191] The bonding tool (216) is instructed to activate to electrically connect the pad (210a) to the wire (244).

[0192] Embodiment 22. The system of embodiment 21, comprising a camera (226) configured to acquire one or more images of the flexible circuit strip (124), wherein the controller (218) is configured to:

[0193] receiving the one or more images of the flexible circuit strip;

[0194] identifying the first connection pad in the one or more images (210a);

[0195] Using the one or more images to determine the bonding tool (216) and the first

[0196] the spatial relationship between the connection pads (210a); and

[0197] The one or more actuators (232) are directed to position the bonding tool (216) over the first connection pad (210a) using the spatial relationship.

[0198] Embodiment 23. The system of any of Embodiments 21 to 22, wherein the bonding tool comprises a cover comprising a heat resistant and electrically conductive material.

[0199] Embodiment 24. The system of Embodiment 23, wherein the one or more electrical connectors are connected to the bonding tool (216) via the bonding tool cover.

Claims

1. A method for electrically connecting a wire to a connection pad of a flexible circuit strip using a bonding tool, the method comprising: receiving the flexible circuit strip on a support surface, wherein the flexible circuit strip comprises a plurality of electrodes, a plurality of connection pads, and a conductive trace connecting each electrode of the plurality of electrodes to a connection pad of the plurality of connection pads; positioning a bonding tool over the first connection pad of the flexible circuit strip; monitoring a first capacitance between the bonding tool and a conductive layer positioned beneath the connection pads, wherein the conductive layer is sized, shaped, and positioned to extend over an entire footprint of the plurality of connection pads; controllably lowering the bonding tool toward the first connection pad until the first capacitance reaches a first predefined capacitance threshold, wherein the first predefined capacitance threshold defines a first height of the bonding tool relative to the flexible circuit strip; monitoring a second capacitance between a first electrode electrically connected to the first connection pad and the bonding tool; controllably lowering the bonding tool from the first height until the second capacitance reaches a second predefined capacitance threshold, wherein the second predefined capacitance threshold defines a second height of the bonding tool relative to the first connection pad; as well as The bonding tool is activated to electrically connect the first connection pad to the conductive line.

2. The method according to claim 1, wherein: The conductive layer is integrated into the flexible circuit strip, wherein the plurality of electrodes and the plurality of connection pads are disposed on an outer surface of the flexible circuit strip.

3. The method according to claim 1, wherein: The conductive layer is an inner layer and the flexible circuit strip includes at least one other layer disposed between the conductive layer and the supporting surface.

4. The method according to claim 1, wherein: The conductive layer is a conductive sheet or film disposed between the support surface and the underside of the flexible circuit strip.

5. The method according to claim 1, wherein: One or more of the following: The support surface is a surface of a support structure comprising a conductive material forming the conductive layer; and The first height and the second height are heights above the top surface of the flexible circuit strip measured in a direction generally away from the top surface of the top surface.

6. The method according to claim 1, comprising one or more of the following: Prior to controllably lowering the bonding tool toward the first connection pad: receiving one or more images of the flexible circuit strip, and controllably adjusting an XY positioning of the bonding tool relative to the first connection pad based on the received one or more images; and The bonding tool is controllably lowered until the tip of the bonding tool contacts the first connection pad.

7. The method according to claim 6, wherein: Controllably lowering the bonding tool until a tip of the bonding tool contacts the first connection pad includes identifying contact between the bonding tool and the first connection pad as a decrease in the second capacitance.

8. The method according to claim 6, comprising one or more of the following: evaluating the quality of the contact using the second capacitance; and For an additional connection pad among the plurality of connection pads: repeating controllably lowering the bonding tool toward the first connection pad until the first capacitance reaches the first predefined capacitance threshold; and monitoring a third capacitance between an additional electrode electrically connected to the additional connection pad and the bonding tool; controllably lowering the bonding tool from the first height until the second capacitance reaches the second predefined capacitance threshold; and The bonding tool is activated to electrically connect the additional connection pads.

9. The method according to any one of claims 1 to 8, wherein: One or more of the following: The activating includes activating a circuit system configured to heat the bonding tool; The bonding tool (216) is a soldering iron or a welding gun or an ultrasonic bonding tool; The first height is less than the second height; the first height is less than 100 μm; and The second height is less than 20 μm.

10. The method according to claim 1, wherein: The bonding tool includes a cover including a heat-resistant and electrically conductive material.

11. A controller for controlling electrical connection of a wire to a connection pad of a flexible circuit strip using a bonding tool movable by one or more actuators, wherein the flexible circuit strip comprises a plurality of electrodes, a plurality of connection pads, and a conductive trace connecting each of the plurality of electrodes to a connection pad of the plurality of connection pads, the controller comprising a circuit system configured to: instructing the one or more actuators to position the bonding tool over a first connection pad of the plurality of connection pads; receiving a measurement of a first capacitance between the bonding tool and a conductive layer positioned beneath the connection pads, wherein the conductive layer is sized, shaped, and positioned to extend over an entire footprint of the plurality of connection pads; instructing the one or more actuators to lower the bonding tool toward the first connection pad until the first capacitance reaches a first predefined capacitance threshold, wherein the first predefined capacitance threshold defines a first height of the bonding tool relative to the flexible circuit strip; receiving a measurement of a second capacitance between an electrode electrically connected to the first connection pad and the bonding tool; instructing the one or more actuators to lower the bonding tool from the first height until the second capacitance reaches a second predefined capacitance threshold, wherein the second predefined capacitance threshold defines a second height of the bonding tool relative to the first connection pad; as well as The bonding tool is instructed to activate to electrically connect the pad to the conductive line.

12. The controller according to claim 11, wherein: The controller is configured to generate a drive signal for measurement of the first capacitance and for measurement of the second capacitance.

13. A system for connecting wires to connection pads of a flexible circuit strip, the flexible circuit strip comprising a plurality of electrodes, a plurality of connection pads, and conductive traces connecting each of the plurality of electrodes to a connection pad of the plurality of connection pads, the system comprising: Joining tools; one or more actuators configured to control a height between the bonding tool and a flexible circuit strip support configured to receive the flexible circuit strip; and one or more capacitive sensors configured to: measuring a first capacitance between the bonding tool and a conductive layer positioned below the connection pads, wherein the conductive layer is sized, shaped, and positioned to extend over an entire footprint of the plurality of connection pads; as well as measuring a second capacitance between the bonding tool and a first electrode electrically connected to the first connection pad; one or more electrical connectors configured to electrically connect the one or more capacitive sensors to the bonding tool, the conductive layer, and the first electrode; A controller, the controller being configured to: instructing the one or more actuators to position the bonding tool over a first connection pad of the plurality of connection pads; receiving a measurement of a first capacitance between the bonding tool and a conductive layer proximate to or as a portion of the flexible circuit strip, wherein the plurality of connection pads are disposed between the conductive element and the bonding tool; instructing the one or more actuators to lower the bonding tool toward the first connection pad until the first capacitance reaches a first predefined capacitance threshold, wherein the first predefined capacitance threshold defines a first height of the bonding tool relative to the flexible circuit strip; receiving a measurement of a second capacitance between an electrode electrically connected to the first connection pad and the bonding tool; instructing the one or more actuators to lower the bonding tool from the first height until the second capacitance reaches a second predefined capacitance threshold, wherein the second predefined capacitance threshold defines a second height of the bonding tool relative to the first connection pad; as well as The bonding tool is instructed to activate to electrically connect the pad to the conductive line.

14. The system of claim 13, comprising a camera configured to acquire one or more images of the flexible circuit strip, wherein the controller is configured to: receiving the one or more images of the flexible circuit strip; identifying the first connection pad in the one or more images; determining a spatial relationship between the bonding tool and the first connection pad using the one or more images; and The one or more actuators are directed to position the bonding tool over the first connection pad using the spatial relationship.

15. A system according to any one of claims 13 to 14, wherein: The bonding tool includes a cover comprising a heat-resistant and electrically conductive material; and Wherein, the one or more electrical connectors are connected to the bonding tool via the bonding tool cover.

Images