Device for dispensing solder wire

Abstract

An apparatus is provided that includes an outlet channel 400 for a solder wire 200 and a first cooling chamber 600 for cooling the solder wire 200 with a first cooling gas 810 within the outlet channel 400, the first cooling gas 810 being configured and arranged to be discharged from a wire-facing outlet 651 away from a substrate 500 and from an outlet 650 toward the substrate 500, the outlet channel 400 for the solder wire 200 being contained within the first cooling chamber 600.

Description

[Technical field]

[0001] Technical Field The present invention relates to an apparatus for dispensing solder lines onto a substrate. [Background technology]

[0002] Prior Art From the prior art, various devices and components for dispensing solder are known, such as those cited below.

[0003] US Patent No. 10399170B2 describes a die attach apparatus for attaching a semiconductor die to a substrate having a metal surface, the die attach apparatus including a material dispensing station for dispensing a bond material onto the substrate, and a die attach station for placing the semiconductor die on the bond material dispensed onto the substrate. An activated gas generator positioned in front of the die attach station introduces activated forming gas onto the substrate to reduce oxides on the substrate.

[0004] EP 1393545 B1 describes a method and apparatus for applying solder to a substrate, which involves melting a solder wire in a mixing chamber and feeding it into a gas flow, and moving or lowering two intermediate nozzles relative to the substrate to spray and deposit the solder from the nozzles onto the substrate. The solder wire is fed into the mixing chamber in a guide tube, and its end is retracted into the guide tube to interrupt the deposition process.

[0005] In U.S. Pat. No. 5,065,932, a nozzle assembly is shown for depositing solder on a series of conductive surfaces, such as mounting pads of a surface mount integrated circuit board. The nozzle assembly includes a nozzle head having an internal bore for receiving an elongated heat source. The nozzle head also includes an orifice for receiving solid solder that is fed into the internal bore for contact with the elongated heat source. The internal bore terminates in a solder reservoir for molten solder that is fed into the internal bore for contact with the elongated heat source. The molten solder is ejected through a tip opening to deposit a uniform amount of solder on each pad. A bleed gas source is provided inside the assembly to protect the components and to exclude oxygen from the interior of the assembly. A cover gas is also provided to the solder site to reduce oxidation of the molten solder and to reduce the amount of flux required.

[0006] Generally, control of conventional solder dispensing processes requires complex multiple functions with multiple nozzles and gas flows to ensure that the solder melts or does not melt in the intended location at the intended time. Additionally, multiple gas flows and gas mixtures can further increase the complexity and operating costs of the equipment. Summary of the Invention [Problem to be solved by the invention]

[0007] Contents of the invention SUMMARY OF THE PRESENT EMBODIMENT It is therefore an object of the present invention to provide a solder dispenser that provides additional functionality without adding complexity. [Means for solving the problem]

[0008] According to the present invention, there is provided an apparatus for dispensing a solder wire onto a substrate, the apparatus comprising a dispensing body, a solder wire discharge channel extending through the dispensing body and configured and arranged to receive the solder wire at a first end and discharge the solder wire from a second end facing the substrate, and a first cooling chamber configured and arranged to cool a region of the solder wire with a first cooling gas within the discharge channel, wherein the first cooling chamber comprises at least one inlet for the first cooling gas, a wire-facing outlet for the first cooling gas, and an outlet for the first cooling gas, such that, in use, the first cooling chamber is configured and arranged to allow the first cooling gas to enter the first cooling chamber through the at least one inlet for the first cooling gas, to be discharged from the wire-facing outlet for the first cooling gas away from the substrate, and to be discharged from the outlet for the first cooling gas towards the substrate, and the discharge channel for the solder wire is contained within the first cooling chamber. By providing a direct flow of the first cooling gas to the solder wire, undesirable variations in process results may be reduced and the complexity of the dispensing apparatus may be reduced. Operating costs may also be reduced due to lower gas consumption.

[0009] Modes for carrying out the invention Embodiments of the device are designed and embodied such that the first cooling chamber and the discharge channel for the solder wire have similar or identical dimensions in one or more regions within the discharge body, which may reduce mechanical complexity, weight and / or volume by allowing a single structure, such as a single hole, to be configured as a significant part of both the discharge channel and the cooling chamber.

[0010] Embodiments of the device are designed and embodied such that the outlet has similar or identical dimensions to the second end of the outlet channel. Additionally or alternatively, the wire-facing outlet has similar or identical dimensions to the first end of the outlet channel. This may further reduce mechanical complexity, weight and / or volume.

[0011] An embodiment of the apparatus is designed and embodied such that the apparatus further comprises at least one auxiliary outlet for the first cooling gas, arranged outside the dispensing body, constructed and arranged to allow, in use, at least a portion of the first cooling gas to pass from the first cooling chamber towards the substrate, which may increase the efficiency of cooling of the wire due to the cooling effect acting even after the wire has left the apparatus.

[0012] An embodiment of the apparatus is designed and implemented such that the first cooling gas comprises nitrogen, carbon dioxide, helium, neon, argon, krypton, hydrogen, carbon monoxide, or any combination thereof, thereby avoiding or reducing oxidation of the substrate and related effects caused by the cooling gas.

[0013] An embodiment of the apparatus is designed and embodied such that the first cooling gas comprises nitrogen and 5% to 20% hydrogen, allowing for low operating costs and a good protective atmosphere for the wire and substrate due to reduced oxidation of the substrate and wire.

[0014] The embodiment of the device is designed and embodied such that the first cooling gas passing through the outlet has a flow in the range of 0.1 to 5 liters per minute. This range of values ​​allows for effective cooling of the wire. In particular, within this range, additional thermal effects on the substrate can be reduced or avoided.

[0015] Embodiments of the apparatus are designed and embodied such that the first cooling gas passing through the wire-facing outlet has a flow in the range of 0.1 to 5 liters per minute, which allows for effective cooling of the wire while minimizing the cooling effect on the substrate.

[0016] An embodiment of the device is designed and embodied such that, when viewed in a longitudinal section through the discharge body and the at least one inlet for the first cooling gas, the at least one inlet for the first cooling gas is arranged at an angle of less than 90 degrees in a counterclockwise direction with respect to the longitudinal axis of the discharge body, which allows the first cooling gas to flow through the wire-facing outlet and the discharge outlet in an optimal ratio, avoiding oxygen from entering the nozzle but preserving high cooling effectiveness.

[0017] An embodiment of the device is designed and embodied such that, when viewed in a longitudinal section through the discharge body and the at least one inlet for the first cooling gas, the at least one inlet for the first cooling gas is disposed at an angle of 30 degrees or more in a counterclockwise direction relative to the longitudinal axis of the discharge body.

[0018] Embodiments of the apparatus are designed and embodied such that, during use, the average temperature of the first cooling gas in at least a portion of the first cooling chamber is predetermined and / or controlled to be at least 50 degrees Celsius below the average melting point of the solder wire, thereby preventing melting of the wire within the apparatus.

[0019] An embodiment of the device further includes a second cooling chamber configured and arranged to cool an area of ​​the discharge body with a second cooling gas, where the second cooling chamber includes at least one inlet for the second cooling gas and at least one outlet for the second cooling gas, whereby the second cooling chamber is designed and embodied such that, in use, the second cooling gas is configured and arranged to allow the second cooling gas to enter the second cooling chamber through the at least one inlet for the second cooling gas and to be discharged from the at least one outlet for the second cooling gas. The second cooling chamber allows more process settings for cooling. Depending on the material, the second cooling may be beneficial to the soldering result if it is performed exclusively or in addition to the first cooling.

[0020] An embodiment of the apparatus is designed and embodied such that the apparatus further comprises at least one auxiliary outlet for the second cooling gas, arranged outside the dispensing body, constructed and arranged to allow the second cooling gas to pass from the second cooling chamber towards the substrate during use, thereby allowing the second cooling gas to flow without affecting the process on the substrate.

[0021] Embodiments of the apparatus are designed and implemented such that the second cooling gas comprises nitrogen, carbon dioxide, helium, neon, argon, krypton, hydrogen, carbon monoxide, oxygen, air, or any combination thereof.

[0022] Embodiments of the apparatus may be designed and implemented such that the second cooling gas and the first cooling gas are the same, which may reduce mechanical and operational complexity.

[0023] Further advantages and features of the invention arise from the following drawings. [Brief description of the drawings]

[0024] [Figure 1A] 1 shows a longitudinal section through an apparatus for dispensing solder wires, illustrating a first cooling feature. [Figure 1B] 1 shows a longitudinal section through an apparatus for dispensing solder wires, showing an optional second cooling feature. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0025] Detailed Description of the Invention Figure 1A shows a longitudinal section through an apparatus 100 for dispensing solder lines 200 onto a substrate 500, showing a first cooling feature. For clarity, only the first cooling feature is shown. An optional second cooling feature is shown in Figure 1B and is described in more detail below.

[0026] 1A shows an apparatus 100 including a dispensing body 300 and a dispensing channel 400 for a solder wire 200 extending through the dispensing body 300. In other words, the dispensing channel 400 is contained within the dispensing body 300. The dispensing channel 400 is configured and arranged to receive the solder wire 200 at a first end 430 and to dispense the solder wire 200 at a second end 470 that faces a substrate 500. The apparatus 100 may be configured and arranged to operate with any suitable type of solder wire 200.

[0027] The apparatus 100 further includes a first cooling chamber 600 constructed and arranged to cool a region of the solder wire 200 with a first cooling gas 810 within the discharge channel 400. The discharge channel 400 for the solder wire 200 is contained within the first cooling chamber 600 - thereby enabling a flow of the first cooling gas 810 to be provided around the solder wire 200 within the discharge body during use.

[0028] More specifically, the first cooling chamber 600 includes at least one inlet 630 for the first cooling gas 810 , a wire-facing outlet 651 for the first cooling gas 810 , and an outlet 652 for the first cooling gas 810 .

[0029] FIG. 1A shows a longitudinal section through the discharge body 300 and at least one inlet 630 for a first cooling gas 810.

[0030] The first cooling chamber 600 is constructed and arranged to allow, during use, a first cooling gas 810 to enter the first cooling chamber 600 through at least one inlet 630 for the first cooling gas 810, to be discharged from a wire-facing outlet 651 for the first cooling gas 810 away from the substrate 500, and to be discharged from an outlet 652 for the first cooling gas 810 towards the substrate 500. This allows a flow of the first cooling gas 810 to be provided around the solder wire 200 away from the substrate 500, towards the area where the solder wire 200 for discharge is received. This further allows a flow of the first cooling gas 810 to be provided around the solder wire 200 in the area towards the substrate 500.

[0031] The apparatus 100 is constructed and arranged, during use, to provide a flow of the first cooling gas 810 around the solder wire 200. Optionally, it may be advantageous to provide a flow of the first cooling gas 810 around the solder wire 200 in substantially all of the discharge channels 400. Additionally or alternatively, it may be advantageous to provide a continuous flow of the first cooling gas 810 for a period of time. Alternatively, it may be advantageous to provide a pulsed flow of the first cooling gas 810 for a period of time.

[0032] In use, a first cooling gas 810 is connected to at least one inlet 630 for the first cooling gas 810 and thereby enters the first cooling chamber 600 which includes the discharge channel 400 .

[0033] The first end 430 that receives the solder wire 200 is disposed at a wire-facing outlet 651 for the first cooling gas 810. The second end 470 for the first cooling gas 810 is disposed at a discharge outlet 652 for the first cooling gas 810.

[0034] Discharge channel 400 is one or more regions that extend from a first end 430 to a second end 470 in close proximity to solder wire 200 during use. Cooling chamber 600 contains discharge channel 400 by including one or more regions with dimensions that are equal to or greater than the dimensions of the respective regions of discharge channel 400.

[0035] Optionally, it may be advantageous if the device 100 is configured such that the first cooling chamber 600 and the discharge channel 400 for the solder wire 200 have similar or identical dimensions in one or more regions within the discharge body 300. For example, as shown in Figures 1A and 1B, a single structure, such as a single hole through the discharge body 300, may be configured and arranged as a significant part of both the cooling chamber 600 and the discharge channel 400. This may reduce mechanical complexity, weight and / or volume.

[0036] Additionally or alternatively, the outlet has similar or the same dimensions as the second end of the outlet channel. Additionally or alternatively, the wire-facing outlet has similar or the same dimensions as the first end of the outlet channel. This may further reduce mechanical complexity, weight and / or volume.

[0037] The flow of the first cooling gas 810 into the discharge channel 400 is divided into two main flows around the solder wire 200: a first main flow 8101 that exits the discharge channel 400 at the second end 470 of the discharge channel 400 toward the substrate 500, and a second main flow 8102 that exits the discharge channel 400 at the first end 430 of the discharge channel 400 away from the substrate 500.

[0038] The second main flow 8102 may be constructed and arranged to reduce a risk of environmental contamination of at least a portion of the outlet channel 400. In particular, it may be advantageous to avoid oxygen contamination of at least a portion of the outlet channel 400.

[0039] The second main flow 8102 may further be advantageous because it allows the apparatus 100 to be constructed and arranged to provide the first cooling gas 810 around the solder wire 200 in substantially all of the discharge channel 400.

[0040] For example, the apparatus 100 may be constructed and arranged to, in use, provide a first cooling gas 810 passing through the outlet 652 at a first main flow 8101 in the range of 0.1 to 5 litres per minute (l / min).

[0041] Additionally or alternatively, the apparatus 100 may be constructed and arranged to provide a first cooling gas 810 passing through the wire-facing outlet 651 at a second main flow 8102 in the range of 0.1 to 5 liters per minute (l / min) during use.

[0042] The apparatus 100 may be constructed and arranged for use in a soft solder process, in which a solder wire 200 is provided to a substrate 500, such as a lead frame. Optionally, during or after dispensing, the dispensed solder 250 may be pressed and / or stamped (optionally by a further apparatus) to provide a larger surface area. Optionally, a predetermined and / or controlled shape may be formed, such as a rectangle or a square. A die may then be bonded to the top surface of the dispensed solder 250, resulting in an intermetallic bond between the lead frame substrate 500 and the die. Typically, such soft solder processes are performed at a temperature of approximately 380 degrees Celsius (°C).

[0043] The present invention is based, at least in part, on the insight that conventional dispensing devices that rely on indirect cooling are inefficient. Cooling is considered indirect when the cooling gas is provided without direct contact with the solder wire. In other conventional devices where forming gas is applied, a separate gas distribution system, typically with a dedicated gas outlet, is used to deliver the forming gas close to the solder on the substrate surface 500 during and / or after dispensing.

[0044] Providing a configurable flow of the first cooling gas 810 around the solder wire 200 may be advantageous due to higher cooling efficiency. This may reduce the variability of process parameters, which in turn may result in a more consistently and repeatably dispensed solder 250. The consistency and / or repeatability may be assessed by using one or more characteristics, such as, for example, shape, size, curvature, volume, area, wetting angle, absolute position on the substrate 500, relative position on the substrate 500, or any combination thereof.

[0045] The present invention is also based, at least in part, on the insight that in conventional discharge devices that rely on indirect cooling, relatively high flow rates are required to provide stable and reliable discharge in a controlled manner. High gas flow rate settings, such as above 20 liters per minute (l / min), are required, which can increase operating costs.

[0046] Furthermore, many conventional devices use gas flow primarily to reduce the risk of oxidation in areas close to the substrate. However, the present invention is also based, at least in part, on the insight that direct cooling of the solder wire 200 in the discharge channel 400 is more advantageous.

[0047] Generally, these conventional discharge devices and discharge nozzles are relatively complex, making them expensive to manufacture. The inventors have empirically determined that these complex devices may exhibit undesirable leakage of indirect cooling gas when operated at relatively high flow rates. In the past, those skilled in the art have attempted to reduce the undesirable leakage, for example, by reducing the dimensional tolerances and / or mechanical stresses in the mechanical parts of the devices and by sealing using high temperature ceramic pastes.

[0048] By providing a direct flow of the first cooling gas 810 to the solder wires 200 in accordance with the present invention, undesirable variations in process results may be reduced.

[0049] In some apparatus 100, the required flow of first cooling gas 810 may be reduced, which may lower operating costs by reducing cooling gas consumption in some apparatus 100. This may also reduce the complexity of the solder dispensing apparatus 100.

[0050] In some devices 100, the weight and / or volume of the solder dispensing device 100 may be reduced.

[0051] Any suitable gas, gas composition, or gas mixture may be used as the first cooling gas 810 for the process being performed - for example, the first cooling gas 810 may include nitrogen, carbon dioxide, helium, neon, argon, krypton, hydrogen, carbon monoxide, or any combination thereof.

[0052] Additionally or alternatively, the first cooling gas 810 may include nitrogen and 5% to 20% hydrogen.

[0053] Optionally, the apparatus may be constructed and arranged to provide the first cooling gas 810 such that the average temperature in at least a portion of the first cooling chamber 600 is predetermined and / or controlled to be at least 50° C. below the average melting point of the solder wire 200. For example, the apparatus 100 may further include one or more coolers (not shown) fluidly prior to or immediately prior to the at least one inlet 630 for the first cooling gas 810. For example, the melting point temperature of the solder 200 is generally in the range of 300° C. to 400° C. In some special processes, the melting point temperature may reach up to 1000° C.

[0054] It may also be advantageous to provide the first cooling gas 810 such that the average temperature in substantially all of the discharge channels 400 is predetermined and / or controlled to be 50° C. or more below the average melting point of the solder wires 200 .

[0055] Optionally, the first cooling gas 810 may be provided such that in the region proximate the outlet 652, the average temperature is predetermined and / or controlled to be 50° C. or more below the average melting point of the solder wire 200.

[0056] For example, when discharging solder wire 200 with a melting point in the range of 300°C to 400°C, the first cooling gas 810 can be provided such that the average temperature, when measured, is in the range of 100°C to 150°C, approximately 1 mm away from the discharge port 652 in idle mode.

[0057] Figure IB shows a longitudinal section through apparatus 100 when illustrating a second optional cooling function. Apparatus 100 shown in Figure IB is the same as the apparatus shown in and described in relation to Figure 1A, although for clarity, some features shown in Figure 1A are not shown in Figure IB. This second optional cooling function is indirect, and is constructed and arranged to operate simultaneously with the first cooling function.

[0058] In particular, FIG. 1B illustrates the apparatus 100 including a second cooling chamber 700 constructed and arranged to cool a region of the dispensing body 300 with a second cooling gas 820 .

[0059] The second cooling chamber 700 includes at least one inlet 730 for the second cooling gas 820 and at least one outlet 750 for the second cooling gas 820. The second cooling chamber 700 includes at least one outlet 750. Any suitable number of outlets 750 may be used. For example, FIG. 1B shows two outlets 750 for the second cooling gas 820. Optionally, a modified mechanical construction may be used to provide only one outlet 750 for the second cooling gas 820.

[0060] As such, Figure 1B shows a longitudinal section through the discharge body 300, at least one inlet 630 for a first cooling gas (not shown), at least one inlet 730 for a second cooling gas 820, and two outlets 750 for the second cooling gas 820. Figure 1B shows an example - those skilled in the art will realise that the inlets and outlets do not have to be located in the same longitudinal section.

[0061] The second cooling chamber 700 is constructed and arranged to allow a second cooling gas 820 to enter the second cooling chamber 700 through at least one inlet 730 for the second cooling gas 820 and to exit through at least one outlet 750 for the second cooling gas 820 during use.

[0062] Optionally, the second cooling gas 820 exhausted from the at least one outlet 750 may be directed away from the substrate 500 .

[0063] Any suitable gas, gas composition, or gas mixture may be used as the second cooling gas 820 for the process being performed - for example, the second cooling gas 820 may include nitrogen, carbon dioxide, helium, neon, argon, krypton, hydrogen, carbon monoxide, oxygen, air, or any combination thereof.

[0064] The second cooling function is optional. The second cooling function may be configured and arranged separately from the first cooling function. Alternatively, the second cooling function may be configured and arranged to cooperate with the first cooling function to achieve the required degree of cooling.

[0065] The first cooling function may be configured and arranged separately from the optional second cooling function, or, if an optional second cooling function is provided, the first cooling function may be configured and arranged to cooperate with the second cooling function to achieve the required degree of cooling.

[0066] As shown in FIG. 1A and described above, the first cooling function includes a flow of a first cooling gas 810 into the discharge channel 400, which is divided into a first main flow 8101 toward the substrate 500 and a second main flow 8102 away from the substrate 500.

[0067] 1A, the apparatus 100 may further optionally be constructed and arranged such that, when viewed in a longitudinal section through the discharge body 300 and the at least one inlet 630 for the first cooling gas 810, the at least one inlet 630 is disposed at an angle 950 of less than 90 degrees in a counterclockwise direction with respect to a longitudinal axis 900 of the discharge body 300. The angle 950 of the at least one inlet 630 may be determined using an axis of symmetry 920 of the at least one inlet 630. This angle 950 may be predetermined and / or controlled to modify the flow ratio of a first main flow 8101 towards the substrate 500 and a second main flow 8102 away from the substrate 500.

[0068] For example, it may be advantageous if the angle 950 is in the range of 30 degrees to 90 degrees.

[0069] For example, it may also be advantageous if the angle 950 is within the range of 70 degrees to 90 degrees.

[0070] By predetermining and / or controlling this angle 950, the ratio of the first main flow 8101 towards the substrate 500 and the second main flow 8102 away from the substrate 500 may be modified. For example, at an angle 950 of approximately 90 degrees, the ratio may be approximately 1:1. For example, by making the angle 950 significantly smaller than 90 degrees, the first main flow 8101 towards the substrate 500 may be relatively increased, while maintaining a sufficient volume of the second main flow 8102, to reduce the risk of environmental contamination into at least a portion of the discharge channel 400 through an opening such as the wire-facing outlet 651.

[0071] The inventors have determined that the use of direct cooling (first cooling function) in accordance with the present invention can provide process quality that is at least comparable to conventional methods that use only indirect cooling.

[0072] For these measurements, an apparatus 100 as shown in Figures 1A and 1B was realized by modifying a conventional type of wire dispenser apparatus suitable for soft solder processes. The conventional indirect cooling function of the conventional wire dispenser apparatus was configured and arranged as the second cooling function shown in Figure 1B and described in this disclosure. A direct cooling function was added to the wire dispenser apparatus and configured and arranged as the first cooling function shown in Figure 1A and described in this disclosure.

[0073] An embodiment of the line dispenser apparatus may include an inlet distributor 670 for a first cooling gas 810 fluidly connected to the discharge channel 400. In this example, the first cooling chamber 600 and the discharge channel 400 may have similar or the same dimensions in one or more regions within the discharge body 300.

[0074] An embodiment of the line dispenser device, when viewed in a longitudinal cross section through the dispensing body 300 and the at least one inlet 630 for the first cooling gas 810, may be positioned at an angle 950 of approximately 70 degrees in a counterclockwise direction relative to the longitudinal axis 900 of the dispensing body 300.

[0075] An embodiment of the wire dispenser device may leave the original discharge channels 400 with an average pore size of 0.4-1.2 mm for use with solder wires 200 having an average diameter in the range of 0.2-1.0 mm.

[0076] To measure relative performance, results from representative processes were selected for comparison: average volume of dispensed solder in cubic millimeters (mm3), variation calculated as the standard deviation divided by the average volume, in percentage (%), and line slippage in microns (μm).

[0077] Both the primary (direct) and secondary (indirect) cooling functions were connected using flow regulators to investigate the effect of different flow conditions. Measurements made with flow through only the secondary cooling function (measurements no. 01-03) were considered to be an acceptable approximation of operation using an unmodified conventional line dispenser device.

[0078] [Table 1]

[0079] Measurements 01-03 were performed using only indirect cooling using the secondary cooling function as an acceptable approximation of the conditions using a conventional wire dispenser. Measurement 01 can be considered to represent the standard operating conditions of a soft solder process using a conventional wire dispenser.

[0080] In comparison, measurement 04 was performed with a small amount of indirect cooling and direct cooling of the first cooling function.

[0081] In comparison, measurements 05-11 were performed with direct cooling only.

[0082] The measurement results in Table 1 show that when there is a variation in the indirect cooling flow from the typical flow rates of 25 l / min to 3 l / min as provided by measurements 01 to 03, a significant increase (deterioration) in the variation up to 2.72% is observable at an indirect cooling flow rate of 3 l / min as provided by measurement 03. This corresponds to an approximately 90% decrease in the indirect flow rate compared to the standard operating conditions of measurement 01.

[0083] If we reduce the indirect cooling to 1 l / min and the direct cooling is 0.5 l / min as provided by measurement 04, the variation again decreases to 1.51%, which is comparable to the standard operating conditions of measurement 01, but the reduction in variation represents a direct improvement.

[0084] And when the direct cooling flow rate is increased to 0.8 l / min, a reduction in variability of 1.3% is observed in measurement 05, which is less variability than can be measured under standard operating conditions in measurement 01, but the reduction in variability represents a straightforward improvement.

[0085] With only a direct cooling flow of 0.6 l / min, as observable in measurements 06, 07 and 09, the measurement results show some fluctuation in the scatter, ranging from 1.61% to 1.71%.

[0086] With only a direct cooling flow of 0.5 l / min, as observable in measurements 10 and 11, the measurement results show some fluctuation in the scatter of 1.75% to 1.88%. By comparison with measurement 04, where additional indirect cooling is provided at 1 l / min, it is shown that a further improvement in the process quality can be expected if indirect cooling is used in addition to direct cooling.

[0087] Measurements 04 and 05 show slightly improved levels of variability compared to the standard operating conditions of measurement 01, but with lower total gas usage. In particular, measurement 04 with 0.5 l / min direct cooling and 1 l / min indirect cooling had a total usage of 1.5 l / min, which was a 94% reduction in usage compared to measurement 01. In particular, measurement 05 with only 0.8 l / min direct cooling had a total usage of 0.8 l / min, which was approximately a 95% reduction in usage compared to measurement 01.

[0088] Furthermore, one skilled in the art will note that the line slip remains relatively unchanged during direct cooling only, combined direct and indirect cooling, and indirect cooling only.

[0089] The temperature and cooling of the gas may be predetermined and / or controlled using parameters for direct and / or indirect cooling, such as gas flow, gas composition, gas mixture, chamber dimensions, inlet dimensions, outlet dimensions, channel dimensions, or any combination thereof.

[0090] By following the instructions provided in this disclosure, one or more embodiments of the wire dispenser 100 including a direct cooling flow of the first cooling gas 810 may be optimized to further improve the solder dispense procedure. For example, it may be advantageous to optimize the embodiment to further improve protection of the solder wire (200) during use and to enhance the cleanliness of the solder wire (200) from oxides that may be present.

[0091] Additionally or alternatively, it may be advantageous to optimize one or more embodiments to provide solder wire 200 with low friction and low slippage in discharge channel 400. In this example, solder wire 200 may be considered to be contained within a gas bearing system because discharge channel 400 is filled with first cooling gas 810.

[0092] Additionally or alternatively, it may be advantageous to optimize one or more embodiments to provide a less clogged solder wire 200 by expelling solder particles and / or other contaminants from the outlet 652.

[0093] Additionally or alternatively, it may be advantageous to optimize one or more embodiments to reduce cleaning of the discharge channel 400 by discharging solder particles and / or other contaminants through the wire-facing outlet 651 and / or the discharge port 652.

[0094] Additionally or alternatively, it may be advantageous to optimize one or more embodiments to provide more reliably and repeatably dispensed solder by optimizing a low wetting angle of less than 40 degrees, preferably less than 35 degrees, and most preferably less than 30 degrees, and / or a reduced volumetric variation of less than about a 5 percent standard deviation of the volume of dispensed solder, preferably less than about a 2 percent standard deviation, and most preferably less than about a 1 percent standard deviation.

[0095] Additionally or alternatively, it may be advantageous to optimize one or more of the embodiments to improve the placement accuracy of the dispensed solder 250 (or dots).

[0096] Optionally, the apparatus 100 may further include at least one auxiliary outlet (not shown) for the first cooling gas 810, disposed outside the dispensing body 300, which may be constructed and arranged to allow at least a portion of the first cooling gas 810 to pass from the first cooling chamber 600 towards the substrate 500, during use.

[0097] The at least one auxiliary outlet may further be constructed and arranged to direct at least a portion of the first cooling gas 810 towards the substrate 500 at an angle that is substantially parallel to the longitudinal axis 900 of the discharge body 300 with no offset or a minimal offset of less than 1.0 degrees or 2.0 degrees from the axis, significantly non-parallel to the longitudinal axis 900, at a non-zero angle to the longitudinal axis 900, or any combination thereof. In some forms, it may be advantageous to direct at least a portion of the first cooling gas 810 towards the substrate 500 at an angle that is approximately perpendicular to the longitudinal axis 900. These are angles when viewed in a longitudinal section through the discharge body 300 and the at least one auxiliary outlet for the first cooling gas 810. Preferably, the at least one auxiliary outlet is arranged at one or more positions that are concentrically and symmetrically arranged transversely to the longitudinal axis 900. In other words, the arrangement, when the second end 470 of the solder dispensing channel 400 is viewed from the substrate 500, may resemble a "showerhead" for the first cooling gas 810. This may provide one or more substantially concentric flow regions of the first cooling gas 810 around the wire 200 and / or the dispensed solder 250. Parameters such as the shape, size and number of the at least one outlet may vary depending on the process being performed.

[0098] The embodiments may also be considered advantageous either on their own or in combination with one or more other examples.

[0099] For example, it may be advantageous to modify a conventional discharge channel, e.g., a linear discharge device, by adding at least one inlet for a first cooling gas 810 that is fluidly connected to the original discharge channel and / or linear capillary.

[0100] For example, it may be advantageous to provide one or more gas flow controllers for the first cooling gas 810 to enable an apparatus, a user, an operator, or any combination thereof, to control the flow of the first cooling gas 810.

[0101] For example, it may be advantageous to provide one or more through-holes between at least one inlet 630 for the first cooling gas 810 and the discharge channel 400 to predetermine a significant degree of flow within the discharge chamber 400. These through-holes may be arranged in any suitable configuration and configuration - for example, a plurality of through-holes may be provided in an inlet distributor 670 (as shown in FIG. 1A ). Preferably, the inlet distributor 670 is constructed and arranged to provide flow substantially all around the exterior of the solder wire 200.

[0102] For example, it may be advantageous to provide one or more flow meters to measure the strength of at least a portion of the flow of the first cooling gas 810 .

[0103] For example, it may be advantageous to provide one or more flow meters to measure the strength of at least a portion of the flow(s) of the second cooling gas 820. [Explanation of symbols]

[0104] 100 line discharge device 200 solder wire 250 solder dispensed 300 Discharge body 400 solder wire discharge channel 430 first end of solder discharge channel 470 second end of solder discharge channel 500 boards 600 First cooling chamber 630 First cooling gas inlet 651 wire facing outlet for first cooling gas 652 First cooling gas outlet 670 First cooling gas inlet distributor 700 Second Cooling Chamber 730 Second cooling gas inlet 750 Second cooling gas outlet 810 First cooling gas 8101 First main flow of first cooling gas (towards the substrate) 8102 Second main flow of first cooling gas (away from substrate) 820 Second Cooling Gas 900 Longitudinal axis 920 Axis of symmetry of first cooling gas inlet 950 Gas inlet angle

Claims

1. An apparatus (100) for dispensing solder wires (200) onto a substrate (500), said apparatus (100) comprising: - a discharge body (300); a discharge channel (400) for the solder wire (200) extending through the discharge body (300), the discharge channel (400) being constructed and arranged to receive the solder wire (200) at a first end (430) of the discharge channel (400) and to discharge the solder wire (200) from a second end (470) of the discharge channel (400) facing the substrate (500); and a first cooling chamber (600) constructed and arranged to cool a region of said solder wire (200) by a first cooling gas (810) within said discharge channel (400); Including, the first cooling chamber (600) comprises at least one inlet (630) for the first cooling gas (810), a wire-facing outlet (651) for the first cooling gas (810), and an outlet (652) for the first cooling gas (810), whereby the first cooling chamber (600) is constructed and arranged to allow, in use, the first cooling gas (810) to enter the first cooling chamber (600) through the at least one inlet (630) for the first cooling gas (810), to be discharged from the wire-facing outlet (651) for the first cooling gas (810) away from the substrate (500), and to be discharged from the outlet (652) for the first cooling gas (810) towards the substrate (500); and The apparatus (100), wherein the discharge channel (400) for the solder wire (200) is contained within the first cooling chamber (600).

2. 2. The apparatus of claim 1, wherein the first cooling chamber (600) and the discharge channel (400) for the solder wire (200) have similar or identical dimensions in one or more regions within the discharge body (300).

3. 3. The device of claim 1 or 2, wherein the discharge opening (652) has similar or identical dimensions to the second end (470) of the discharge channel (400), and / or the wire-facing outlet (651) has similar or identical dimensions to the first end (470) of the discharge channel (400).

4. 3. The apparatus of claim 1 or 2, further comprising at least one auxiliary outlet for the first cooling gas (810) arranged outside the discharge body (300), configured and arranged to allow at least a portion of the first cooling gas (810) to pass from the first cooling chamber (600) towards the substrate (500) during use.

5. 3. The apparatus of claim 1 or 2, wherein the first cooling gas (810) comprises nitrogen, carbon dioxide, helium, neon, argon, krypton, hydrogen, carbon monoxide, or any combination thereof.

6. The apparatus of claim 1 or 2, wherein the first cooling gas (810) comprises nitrogen and 5% to 20% hydrogen.

7. The apparatus of claim 1 or 2, wherein the first cooling gas (810) passing through the outlet (652) has a flow in the range of 0.1 to 5 liters per minute.

8. The apparatus of claim 1 or 2, wherein the first cooling gas (810) passing through the wire-facing outlet (651) has a flow in the range of 0.1 to 5 liters per minute.

9. 3. The apparatus of claim 1, wherein, when viewed in a longitudinal section through the discharge body and the at least one inlet for the first cooling gas, the at least one inlet for the first cooling gas is disposed at an angle of less than 90 degrees in a counterclockwise direction relative to a longitudinal axis of the discharge body.

10. 10. The apparatus of claim 9, wherein, when viewed in a longitudinal section through the discharge body (300) and the at least one inlet (630) for the first cooling gas (810), the at least one inlet (630) for the first cooling gas is disposed at an angle (950) of 30 degrees or greater in a counterclockwise direction relative to the longitudinal axis (900) of the discharge body (300).

11. 3. The apparatus of claim 1, wherein, during use, the average temperature of the first cooling gas (810) in at least a portion of the first cooling chamber (600) is predetermined and / or controlled to be at least 50 degrees Celsius below the average melting point of the solder wire (200).

12. 3. The apparatus of claim 1, further comprising a second cooling chamber configured and arranged to cool a region of the discharge body with a second cooling gas, the second cooling chamber comprising at least one inlet for the second cooling gas and at least one outlet for the second cooling gas, whereby the second cooling chamber is configured and arranged to allow the second cooling gas, during use, to enter the second cooling chamber through the at least one inlet for the second cooling gas and to be discharged from the at least one outlet for the second cooling gas.

13. 13. The apparatus of claim 12, wherein the apparatus (100) further comprises at least one auxiliary outlet for the second cooling gas (820) arranged outside the discharge body (300), configured and arranged to allow the second cooling gas (820) to pass from the second cooling chamber (700) toward the substrate (500) during use.

14. 13. The apparatus of claim 12, wherein the second cooling gas (820) comprises nitrogen, carbon dioxide, helium, neon, argon, krypton, hydrogen, carbon monoxide, oxygen, air, or any combination thereof.

15. The apparatus of claim 12, wherein the second cooling gas (820) and the first cooling gas (810) are the same.

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