Solder the electrode wires to the pads in the multi-electrode catheter

Abstract

A method for soldering includes placing solder paste on a pad formed on a substrate and positioning a wire in the solder paste. Gas flows through a nozzle of a blower toward a pipette coupled to the nozzle, and the gas is directed through the distal end of the pipette toward a pad among the pads at a predefined temperature that melts the solder paste. The directed gas is confined by the pipette to impact the pad at an area less than 0.1 mm.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims the benefit of U.S. Provisional Patent Application 63 / 541,307, filed on September 29, 2023. Technical Field

[0003] The present disclosure relates generally to medical devices, and in particular to methods and systems for welding leads of electrodes to pads in a multi-electrode catheter. Background Art

[0004] Some cardiac electrophysiology procedures require high-density mapping and / or tissue ablation using a catheter having a large number of electrodes (e.g., about 100). For example, a basket catheter may have about ten splines and about ten electrodes disposed on each spline. Each spline includes a pad electrically connected to the electrode, both electrodes being formed on a substrate such as a printed circuit board (PCB), and at least ten wires (e.g., one wire for each electrode) extending between the pads on the spline and connected to corresponding pads on a printed circuit board (PCB) of a connector formed at the proximal end of the shaft of the catheter. Thus, the splines and the PCB of the shaft have a large number of pads, which are respectively soldered to a large number of wires.

[0005] The present disclosure will be more fully understood through the following detailed description of examples of the present disclosure in conjunction with the accompanying drawings, in which: BRIEF DESCRIPTION OF THE DRAWINGS

[0006] Figure 1 is a schematic illustration of a system for welding a lead to a pad in a multi-electrode catheter according to an example of the present disclosure;

[0007] Figure 2 is a schematic diagram showing an example of using Figure 1 A flowchart of a method for soldering a wire to a pad using a system; and

[0008] Figure 3 The present invention schematically shows a method for producing Figure 1 Flowchart of the system. DETAILED DESCRIPTION

[0009] Overview

[0010] 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 PCB 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 coupling. The wires extending from each spline may be arranged in a braid or any other configuration. 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. Therefore, the large number of pads and wires requires that the pad size 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 coupling process between the wire and the corresponding pad.

[0011] Examples of the present disclosure described below provide techniques for improving the manufacturing process of coupling the wires of a multi-electrode catheter to their corresponding pads, which are disposed on a substrate, in this example, on a flexible printed circuit board (PCB). In the context of the present disclosure and in the claims, the term PCB refers to a substrate having pads, and in some cases described below, refers to additional components disposed on the substrate. It should be noted that in order to accommodate all of the wires of the catheter within the PCB of the shaft, the size of each pad is reduced to tens of microns. In some examples, each of the wires is soldered to a corresponding pad of the shaft by: (i) disposing solder paste on the surface of each pad, (ii) positioning each wire in the solder paste on each pad, and (iii) soldering the wire to the pad by heating the solder paste to a predefined temperature.

[0012] In some examples, a system for soldering a wire to a pad of a shaft includes a blower assembly having a blower configured to generate a gas flow (such as air or any other suitable gas (CO2) or argon). It should be noted that the flow of air or another gas can be continuous (e.g., a jet) or pulsed. The blower assembly includes a duct having a first end coupled to the blower within the blower assembly and a second end having a nozzle. The duct is configured to flow air toward the nozzle and heat the air to a predefined temperature for melting or softening the solder paste, as will be described in detail below. It should be noted that due to the small size of the pads and the small distance between the pads (as will be described in detail below), it is important to direct the air to the predefined pads intended to undergo the soldering process, but not to heat adjacent pads (e.g., previously soldered pads located to the side of the predefined pads intended to be soldered).

[0013] In some examples, the system includes: (i) a pipette configured to direct air toward each pad individually in order to perform welding; and (ii) a coupler configured to be coupled between the pipette and a nozzle or outlet of a blower. In this configuration, the proximal end of the pipette has a first diameter (e.g., a few hundred microns or a few millimeters) and is coupled to the nozzle via the coupler. In another specific implementation, the nozzle and the coupler may include a single component such that the proximal end of the pipette is directly coupled to the single component. The distal tip of the pipette has a second diameter (e.g., tens of microns), which is typically smaller than the first diameter. The distal tip of the pipette is configured to direct air toward a region of one micron to tens of microns in order to weld a given wire to a given pad, but without melting solder paste disposed on pads adjacent to the given pad. The structural characteristics of the pipette are described below. Figure 1 Described in detail in.

[0014] In some examples, the air is heated by a blower and / or by a coil wound around the outer surface of the pipette so as to direct the air from the pipette toward the pad at a predefined temperature. In one example, the blower can be a hot air blower configured to blow air at a suitable temperature, such as but not limited to a temperature between about 150° C. and 200° C. In another example, the blower is configured to blow air at room temperature and heat the air as it flows through the pipette. Based on the aforementioned coil being wound around the pipette, the air can be heated by the pipette.

[0015] In some examples, the system includes a positioning assembly configured to move the pipette and the PCB relative to each other so as to perform individual soldering of each individual pad to the corresponding wire. The positioning assembly may include a motorized and controlled stage configured to move the PCB along the XYZ axis relative to the pipette, and / or a controlled robotic arm configured to move the pipette relative to the PCB. In both configurations, the positioning assembly is configured to place the distal tip of the pipette opposite to the pad intended to be soldered as described above.

[0016] In some examples, the system also includes a controller configured to control: (i) a blower to control the flow rate of the gas, and (ii) the temperature of the air within and outside the pipette (e.g., by controlling a heating element in the blower and / or current supplied to the coil for heating the air), and (iii) a positioning assembly to position the distal tip of the pipette relative to the pad and wire to be welded.

[0017] Examples of the above components and techniques are specifically implemented below Figure 1 Detailed description is given in further detail in .

[0018] The disclosed technology enables fast and accurate soldering of wires to pads formed on a PCB of at least a shaft and thus improves the quality of a multi-electrode catheter. In addition, the disclosed technology improves efficiency and reduces costs associated with manufacturing such catheters.

[0019] System Description

[0020] Figure 1 is a schematic illustration of a welding system 11 according to an example of the present disclosure.

[0021] In some examples, the system 11 includes a blower assembly 10 configured to blow air or any other suitable type of gas. The blower assembly 10 includes a blower 12 configured to generate an air flow, and a heating element 13, such as a coil (or any other suitable type of heating element), configured to heat the air flowing toward an opening 32 of the blower assembly 10. The blower assembly 10 optionally includes a duct 14 coupled to the opening 32 and configured to flow the air generated by the blower 12. The duct 14 includes a nozzle 16 coupled to a coupler 26, the function of which will be described below.

[0022] In some examples, the system 11 includes a pipette 22, which is typically made of glass, such as tempered borosilicate glass, or any other suitable material configured to withstand a wide range of temperatures (e.g., between about -150°C and +500°C). In this example, the coupler 26 is configured to mechanically couple the nozzle 16 and the proximal end 18 of the pipette 22, which has an inner diameter 34 that fits tightly into or on the coupler 26 and the nozzle 16 so that air generated by the blower assembly 10 can flow into the pipette 22. It should be noted that the coupling of the pipette 22 can be implemented using a mechanical assembly (such as a rotating quick connector), by gluing the pipette to the nozzle 16 or the coupler 26, or using any other suitable coupling technique.

[0023] In some examples, the pipette 22 has a distal segment 20 that includes a distal tip 33 having an inner diameter 19 (e.g., between about 30 μm and 60 μm) that is configured to direct air toward a substrate, which in this example is a printed circuit board (PCB) 77, the structure and function of which are described below.

[0024] Referring now back to illustration 30 for a description of the PCB 77. In some examples, the basket catheter 50 includes a plurality of splines 52 comprising a flexible printed circuit board strip having a plurality of electrodes 54 formed thereon (and / or coupled thereto). The flexible printed circuit board strip may be coupled to any suitable flexible spline (e.g., made of a nickel-titanium alloy, also known as Nitinol). In this example, the basket catheter 50 includes about ten splines 52, each spline 52 including about ten electrodes 54 coupled to ten respective pads (not shown) formed on the respective spline 52 for connection between the electrodes 54 and conductive wires, which in this example are electrical traces (not shown) extending through the respective strips 52.

[0025] In some examples, such procedures for EP mapping and tissue ablation are described in U.S. Patents 5,391,199; 5,443,489; 5,558,091; 6,172,499; 6,239,724; 6,332,089; 6,484,118; 6,618,612; 6,690,963; 6,788,967; 6,892,091; and U.S. Patent Applications 15 / 279,570; 16 / 896,104; 17 / 374,849; and 17 / 749,654.

[0026] Now return to see Figure 1 , which shows a cross-sectional view of the system 11 and a PCB 77, pads 44, and wires 66 soldered to the pads 44. In some examples, the PCB 77 has at least 100 pads 44 and at least 100 wires 66 connected to the 100 electrodes 54, respectively. The wires 66 configured to exchange signals between the PCB 77 and the electrodes 54 are soldered to the pads 44, respectively, using molten solder paste 55. It should be noted that in order to accommodate about 100 pads 44 on the PCB 77, each pad 44 has a size 24 of several tens of microns along the X-axis and the Y-axis of the XYZ coordinate system of the system 11.

[0027] In some examples, in the following Figure 2In the soldering process sequence described in detail in , (i) solder paste 55 is disposed on pads 44, (ii) wire 66 is placed in or on solder paste 55, and (iii) the stack of pads 44, solder paste 55, and wire 66 is soldered by directing heated air toward each pad 44 having solder paste 55 and wire 66 disposed thereon. It should be noted that due to the small size of pads 44, it is important to direct the hot air directly and individually to each pad 44 within a precisely controlled predefined time interval, otherwise solder paste 55 may flow between adjacent pads, thereby causing electrical shorts and failure of PCB 77. Therefore, the manual soldering method may increase the duration and cost associated with soldering of wire 66 and pads 44.

[0028] In some examples, the coil 17 is wound around the outer surface of at least the proximal end 18 of the pipette 22. The coil 17 is configured to heat air directed to the PCB 77 so as to heat the solder paste to a predefined temperature (e.g., between about 90° C. and 400° C., depending on the thermal characteristics of the solder paste 55).

[0029] In some examples, the air is heated by the heating element 13 of the blower assembly 10 and / or by the coil 17 so as to direct the air from the pipette 22 toward each individual pad 44 at the aforementioned predefined temperature. In the present example, because the size of the inner diameter 19 is between about 30 μm and 60 μm, the pipette 22 is configured to limit the directed air (which is heated to the predefined temperature) to impact the pad 44 (and the solder paste 55 and wire 16 stacked thereon) at an area less than 0.1 mm. As described above, each pad 44 has a size 24 of several tens of microns along the X-axis and the Y-axis, so that the directed air is limited to heating only the solder paste 55 disposed on the predefined pad 44 (and thereby soldering the wire 66 to the predefined pad 44), but does not melt the solder paste 55 disposed on other pads 44 of the PCB 77.

[0030] In some examples, the system 11 and the positioning assembly 15 are configured to move the pipette 22 and the PCB 77 relative to each other in order to perform individual soldering of each individual pad 44 and the corresponding wire 66 to each other using solder paste 55. In this example, the positioning assembly 15 is implemented in the form of a motorized and controlled stage that is configured to move the PCB 77 relative to the distal end 33 of the pipette 22 along the XYZ axis. Figure 1 In the example of , welding is performed when the distal tip 33 is positioned opposite to a single stack of pads 44, solder paste 55 and wire 66 along the X-axis and Y-axis and is positioned at a distance 23 along the Z-axis between, for example, the wire 66 and the distal tip 33.

[0031] Additionally or alternatively, the positioning assembly can be implemented in the form of a controlled robotic arm (not shown) that is disposed between the blower assembly 10 and the duct 14 (or at any other suitable location within the system 11) and is configured to move the pipette 22 relative to the PCB 77. In both configurations, the positioning assembly is configured to place the distal tip 33 of the pipette 22 opposite a given solder pad 44 that is intended to be soldered as described above.

[0032] In some examples, the system 11 also includes a controller 88, which is implemented in the form of a computer in this example. The controller 88 is electrically coupled to the blower 12, the heating element 13, the coil 17, and the positioning assembly 15 via the cable 35, and is configured to control: (i) the blower 12 to control the flow rate of air (or any other suitable gas), (ii) the heating element 13 (of the blower assembly 10) and / or the coil 17 (wound around the pipette 22) to control the temperature of the air flowing through the conduit 14, flowing within the pipette 22 and out of the distal end 33 toward the PCB 77, and (iii) the positioning assembly 15 to position the distal end 33 of the pipette 33 opposite the solder pad 44 and the wire 66 to be soldered, and at a distance 23 between the pipette 33 and the wire 66.

[0033] In some examples, the controller 88 is connected to a display 89 that is configured to display an image of the PCB 77 and one or more pads 44 intended to be soldered (as described above) and information related to controlling the blower assembly 10, the heating elements 13 and 17, and the positioning assembly 15. It should be noted that for ease of presentation, Figure 1 Some of the components in FIG. 8 are shown at different sizes. For example, in reality, the controller 88, display 89, and blower assembly 10 are significantly larger than the PCB 77 and pipette 22, but this non-linear presentation is required to describe the features of the present disclosure.

[0034] In some examples, distance 23 may be between about 0.3 mm and about 3 mm (e.g., about 1 mm), which is measured using one or more cameras (not shown). In other examples, a metal layer 21 (e.g., a gold layer) may be coated on at least the outer surface of distal tip 33 so as to control distance 23 by measuring the capacitance level between distal tip 33 and wire 66 (or pad 44). In this example, layer 21 acts as an electrode configured to measure the capacitance between distal tip 33 of pipette 22 and pad 44 (or alternatively, between distal tip 33 and wire 66 disposed on pad 44 and solder paste 55).

[0035] In some examples, controller 88 may control the temperature of the air at distal tip 33 by operating one or both of heating element 13 and coil 17 via cable 35. It should be noted that system 11 may include one or more temperature sensors (not shown) disposed at several locations along system 11, and more specifically near distal tip 33, to provide a signal to controller 88 indicative of the temperature of the air.

[0036] This particular configuration of the system 11 is shown by way of example in order to illustrate certain problems solved by the examples of the present disclosure and to demonstrate the application of these examples in enhancing the performance of such systems. However, the examples of the present disclosure are by no means limited to this particular configuration and class of example systems, and the principles described herein may be similarly applied to other classes of welding systems.

[0037] Figure 2 is a flow chart schematically illustrating a method for soldering a wire 66 to a pad 44 using the system 11 according to an example of the present disclosure.

[0038] The method begins with a printed circuit board mounting step 100, wherein a PCB 77 having pads 44 is mounted on a positioning assembly 15, as described above. Figure 1 Described in more detail in .

[0039] At the solder paste placement step 102, solder paste 55 is placed on the surface of the pad 44, as described above. Figure 1 In some examples, solder paste 55 may be disposed on the surface of pad 44 using any suitable technique, such as, but not limited to, dispensing, spraying, spreading, or depositing using any suitable type of dispensing, printing, and layer deposition system.

[0040] At the wire positioning step 104, the wire 66 is positioned in the solder paste 55 disposed on each pad 44, as described above. Figure 1 As described in .

[0041] At the hot air generation step 106, the controller 88 controls the blower assembly 10 and optionally the coil 17 to generate a hot air flow into the pipette 22. In some examples, the controller 88 is configured to control the heating of the air using at least one of the heating element 13 of the blower assembly 10 and the coil 17 wrapped around the proximal end 18 of the pipette 22, as described above. Figure 1 Described in more detail in .

[0042] At the pipette positioning step 108, the controller 88 controls the positioning assembly 15 to position the distal tip 33 of the pipette 22 to be: (i) opposite to the pad 24 along the X-axis and the Y-axis, and (ii) a distance 23 (e.g., between about 0.3 mm and 3 mm) from the wire 66 intended to be soldered to the pad 24 along the Z-axis. Subsequently, the controller 88 controls the execution of the soldering process by directing hot air toward the pad 44, the solder paste 55, and the wire 66, as described above. Figure 1 Described in detail in .

[0043] In some examples, the hot air directed toward the solder pad 44 may be a continuous jet of hot air, or pulses of hot air directed to the solder pad 44 to perform the soldering process.

[0044] It should be noted that the order of steps 104, 106, and 108 is provided by way of example, and these operations may be implemented using any other suitable order. In one example, the order of steps 106 and 108 may be reversed so that after positioning the distal tip 33, the controller 88 controls the blower assembly 10 and the coil 17 to generate hot air that is immediately directed from the pipette 22 toward the pad 44, the solder paste 55, and the wire 66 intended to be soldered. In another example, the system 11 may include a valve (not shown) disposed at one or more of the following: (i) the opening 32, (ii) the nozzle 16 and / or the coupler 26 (e.g., the valve may replace the coupler 26), and (iii) at any suitable location along the pipette 22. In this example, using the above-described techniques, hot air may be generated simultaneously with any of the steps of the method while the controller 88 controls the valve to be in a closed position. Subsequently, the controller 88 controls the valve to be in the open position (and thereby causes hot air to flow through the distal tip 33) only when the distal tip 33 of the pipette 22 is positioned in front of the stack of pads 44, solder paste 55 and wires 66 and is a distance 23 from the wires 66, as described above in Figure 1 Neutralize as described in step 108.

[0045] At decision step 110, the controller 88 checks whether additional wires 66 need to be soldered to the corresponding pads 44. In the event that additional soldering is required, the method loops back to step 108. Alternatively, the method proceeds to a PCB unloading step 112, which ends the method, wherein the controller 88 controls (i) the positioning assembly 15 to unload the PCB 77, or controls (ii) a robot (not shown) to unload the PCB 77 from the positioning assembly 15.

[0046] Figure 3 is a flow chart schematically illustrating a method for generating the system 11 according to one example of the present disclosure.

[0047] The method begins with a coil winding step 200, in which a coil 17 is wound around at least a section of a pipette 22, in this example, the proximal end 18 of the pipette 22, as described above. Figure 1 Furthermore, the coil 17 is coupled to a cable 35 which is configured to supply current to the coil 17 in order to heat the air.

[0048] At metal coating step 202, layer 21 (made of gold or of any other suitable material) is disposed at least on distal tip 33 (and in some cases also on additional portions of segment 20), as described above in Figure 1 Described in detail in .

[0049] In alternative examples, steps 200 and 202 may be performed in reverse order, or (less likely) even simultaneously.

[0050] At the coupling step 204 concluding the method, the pipette 22 is coupled to the nozzle 16 using the coupler 26 or any other suitable technique, as described above in Figure 1 Described in more detail in .

[0051] In an alternative example, steps 204 and 206 may be implemented in the reverse order. Figure 2 In the case of a valve as described in the foregoing, the method may include a valve integration step in which the valve is integrated with one or more components of the system 11 (described above). Figure 2 ) coupling.

[0052] It should be noted that one or more of the above steps may be omitted from the production method in cases where any other components may have been pre-assembled (eg, by a subcontractor).

[0053] Although the examples described above primarily involve precisely soldering wires to pads on a printed circuit board on a catheter shaft, the methods and systems described herein may also be used in other applications, such as soldering wires into splines of a multi-electrode catheter, or in any other manufacturing process for catheters or other components of a medical system that requires deep sub-millimeter levels of precision.

[0054] Example 1

[0055] A system (11) comprising: (a) a blower (10) configured to generate a gas flow toward a substrate (77) including a pad (44) on which solder paste (55) is disposed, the blower (10) including a nozzle (16) configured to blow the gas out of the blower (10), (b) a pipette (22) coupled to the nozzle (16) and configured to: (i) receive the gas from the nozzle (16) at a proximal end of the pipette (22), (ii) cause the gas to flow through the pipette (22) ), and (iii) directing the gas toward the pad (44) among the pads (44) through the distal end (33) of the pipette (22) at a predefined temperature for melting the solder paste (55), wherein the pipette (22) is configured to confine the directed gas at the predefined temperature to impact the pad (44) at an area less than 0.1 mm, and (c) a coupler (26) disposed between the nozzle (16) and the pipette (22) and configured to be coupled between the nozzle (16) and the pipette (22).

[0056] Example 2

[0057] The system according to embodiment 1 further includes a coil (17) wound around the outer surface of the pipette and configured to heat the gas directed to the pad to the predefined temperature.

[0058] Example 3

[0059] The system according to embodiment 1 further includes an electrode (21) coupled to the outer surface of the pipette and configured to measure the capacitance between the distal tip of the pipette and the pad.

[0060] Example 4

[0061] A system as described in Example 3, wherein the measured capacitance indicates the distance between the distal tip of the pipette and the pad.

[0062] Example 5

[0063] A system as described in Example 3, wherein the electrode comprises a metal layer coated on the outer surface of the pipette.

[0064] Example 6

[0065] A system as described in Example 1, wherein the proximal end of the pipette has a first diameter and the distal end of the pipette has a second diameter, the second diameter being smaller than the first diameter and less than ten microns.

[0066] Example 7

[0067] The system according to embodiment 1 further comprises a controller configured to control:

[0068] (i) a blower to control the flow rate of the gas, and (ii) the temperature of the gas flowing (i) within the pipette and (ii) at the distal tip of the pipette.

[0069] Example 8

[0070] The system according to Example 7 further includes a positioning assembly (15) configured to move the pipette and the PCB relative to each other, and wherein the controller is configured to control the positioning assembly to position the distal tip of the pipette: (i) opposite to the pad along at least a first axis, and (ii) at a predefined distance from the pad along a second axis.

[0071] Example 9

[0072] The system according to embodiment 1 further includes a conduit (14) positioned between the nozzle and the coupler and configured to be connected between the blower and the pipette.

[0073] Example 10

[0074] A system as described in embodiment 1, wherein the pipette comprises tempered borosilicate glass.

[0075] Embodiment 11

[0076] A system as in embodiment 1, wherein the gas is heated to at least the predefined temperature before entering the pipette.

[0077] Example 12

[0078] A method comprising:

[0079] A coupler (26) is coupled to a nozzle (16) located at the end of a blower (10) for flowing a gas; and a pipette (22) made of glass is coupled to the nozzle (16) for directing the gas toward a substrate (77), wherein a proximal end of the pipette (22) is coupled to the coupler (26) and has a first diameter (34), and a distal end (33) of the pipette (22) has a second diameter (19) smaller than the first diameter (34).

[0080] Example 13

[0081] A method according to Example 12, wherein coupling the pipette includes coupling a pipette made of tempered borosilicate glass.

[0082] Embodiment 14

[0083] A method according to embodiment 13, wherein the substrate comprises at least a pad (44) having a solder paste (55) and a wire (66) disposed thereon, and the method comprises winding a coil (17) around an outer surface of the pipette.

[0084] Embodiment 15

[0085] The method according to embodiment 14 also includes heating the gas directed to the pad to a predefined temperature by applying at least one of the following items: (i) a coil wound around the outer surface of the pipette, and (ii) a heating element for heating the gas flowing through the blower.

[0086] Example 16

[0087] The method according to embodiment 14 also includes coupling an electrode to the outer surface of the pipette for measuring the capacitance between the distal end of the pipette and the pad, wherein the measured capacitance indicates the distance between the distal end of the pipette and the pad.

[0088] Embodiment 17

[0089] A method as in Example 16, wherein coupling the electrode comprises coating at least the distal tip of the pipette with a conductive layer.

[0090] Embodiment 18

[0091] The method according to Example 14 also includes connecting a controller to control: (i) the flow rate of the gas, and (ii) the temperature of the gas within the pipette and outside the pipette.

[0092] Embodiment 19

[0093] The method according to embodiment 18 also includes connecting the controller to a positioning assembly for moving the pipette and the substrate relative to each other, and for positioning the distal end of the pipette to: (i) be opposite to the pad along at least a first axis, and (ii) be at a predefined distance from the pad along a second axis.

[0094] Embodiment 20

[0095] A method for welding, the method comprising:

[0096] A solder paste (55) is disposed on a pad (44) formed on a substrate (77), and a wire (66) is positioned in the solder paste (55); a gas is caused to flow through a nozzle (16) of a blower (10) toward a pipette (22) coupled to the nozzle (16); and the gas is directed through a distal end (33) of the pipette (22) toward a pad (44) among the pads (44) at a predefined temperature at which the solder paste (55) melts, wherein the directed gas is confined by the pipette (22) to impact the pad (44) at an area less than 0.1 mm.

[0097] It should be understood that the above examples are cited by way of example, and the present disclosure is not limited to what is specifically shown and described above. On the contrary, the scope of the present disclosure includes combinations and sub-combinations of the various features described above and their variations and modifications, which will occur to a person skilled in the art when reading the above description and which are not disclosed in the prior art. The documents incorporated by reference into this patent application are considered an integral part of this application, unless any term defined in these incorporated documents conflicts with the definition explicitly or implicitly given in this specification, in which case only the definition in this specification shall be considered.

Claims

1. A system comprising: a blower configured to generate a gas flow toward a substrate, the substrate comprising a pad having solder paste disposed thereon, the blower comprising a nozzle configured to blow the gas out of the blower; a pipette coupled to the nozzle and configured to: receiving the gas from the nozzle at a proximal end of the pipette; flowing the gas through the pipette; as well as directing the gas through the distal tip of the pipette toward a pad among the pads at a predefined temperature to melt the solder paste, wherein the pipette is configured to confine the directed gas at the predefined temperature to impact the pad at an area less than 0.1 mm; as well as A coupler is disposed between the nozzle and the pipette and is configured to be coupled between the nozzle and the pipette.

2. The system of claim 1, and comprising a coil wound around an outer surface of the pipette and configured to heat the gas directed to the pad to the predefined temperature.

3. The system of claim 1, and comprising an electrode coupled to an outer surface of the pipette and configured to measure capacitance between the distal tip of the pipette and the pad.

4. The system according to claim 3, wherein: The measured capacitance is indicative of the distance between the distal tip of the pipette and the pad.

5. The system according to claim 3, wherein: The electrode comprises a metal layer coated on the outer surface of at least the distal tip of the pipette.

6. The system according to claim 1, wherein: The proximal end of the pipette has a first diameter and the distal end of the pipette has a second diameter that is smaller than the first diameter and is less than ten microns.

7. A system according to claim 1, and including a controller configured to control: (i) the blower to control the flow rate of the gas, and (ii) the temperature of the gas flowing (i) within the pipette and (ii) at the distal tip of the pipette.

8. The system of claim 7, and comprising a positioning assembly configured to move the pipette and the substrate relative to each other, and wherein the controller is configured to control the positioning assembly to position the distal tip of the pipette to: (i) opposite to the pad along at least a first axis, and (ii) at a predefined distance from the pad along a second axis.

9. The system of claim 1 and comprising a conduit positioned between the nozzle and the coupler and configured to connect between the blower and the pipette.

10. The system according to claim 1, wherein: The pipette comprises tempered borosilicate glass.

11. The system according to claim 1, wherein: The gas is heated at least to the predefined temperature before entering the pipette.

12. A method comprising: coupling a coupler to a nozzle at an end of the blower for flowing the gas; as well as A pipette made of glass is coupled to the nozzle for directing the gas toward the substrate, wherein a proximal end of the pipette is coupled to the coupler and has a first diameter, and a distal tip of the pipette has a second diameter smaller than the first diameter.

13. The method according to claim 12, wherein: Coupling the pipette includes coupling the pipette made of tempered borosilicate glass.

14. The method according to claim 13, wherein: The substrate includes at least a solder pad having solder paste and a wire disposed thereon, and the method includes winding a coil around an outer surface of the pipette.

15. A method according to claim 14, and comprising heating the gas directed to the pad to a predefined temperature by applying at least one of the following: (i) a coil wound around the outer surface of the pipette, and (ii) a heating element for heating the gas flowing through the blower.

16. The method of claim 14, and comprising coupling an electrode to an outer surface of the pipette for measuring capacitance between the distal tip of the pipette and the pad, wherein the measured capacitance is indicative of a distance between the distal tip of the pipette and the pad.

17. The method according to claim 16, wherein: Coupling the electrodes includes coating at least the distal tip of the pipette with a conductive layer.

18. The method of claim 15, and comprising connecting a controller for controlling: (i) the flow rate of the gas, and (ii) the temperature of the gas within the pipette and outside the pipette.

19. A method according to claim 18, and including connecting the controller to a positioning assembly for moving the pipette and the substrate relative to each other, and for positioning the distal tip of the pipette to: (i) be opposite to the pad along at least a first axis, and (ii) be at a predefined distance from the pad along a second axis.

20. A method for welding, comprising: disposing solder paste over pads formed on a substrate and positioning a wire in the solder paste; causing gas to flow through a nozzle of a blower toward a pipette coupled to the nozzle; as well as The gas is directed through the distal tip of the pipette toward a pad among the pads at a predefined temperature that melts the solder paste, wherein the directed gas is confined by the pipette to impact the pad at an area less than 0.1 mm.

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