CN117957083A

CN117957083A - Device for dispensing bonding wire

Info

Publication number: CN117957083A
Application number: CN202280063283.7A
Authority: CN
Inventors: 海因里希·柏赫托德; 洛伦佐·格巴尼
Original assignee: Besi Switzerland AG
Current assignee: Besi Switzerland AG
Priority date: 2021-08-04
Filing date: 2022-08-04
Publication date: 2024-04-30
Also published as: TW202327768A; DE112022003797T5; WO2023012716A1; JP2024530935A

Abstract

The present invention provides an apparatus comprising: a distribution channel 400 for a bonding wire 200; a first cooling chamber 600 for cooling the bonding wire 200 by a first cooling gas 810 in the distribution channel 400, the first cooling gas 810 being constructed and arranged to flow away from the substrate 500 from a wire-facing outlet 651 and out from the distribution outlet 650 toward the substrate 500; wherein the distribution channel 400 for the bonding wire 200 is contained within the first cooling chamber 600.

Description

Device for dispensing bonding wire

Technical Field

The present invention relates to an apparatus for dispensing bonding wires on a substrate.

Background

From the current state of the art, various devices and components for dispensing solder are known, such as those referenced below.

US 10399170B 2 describes a die attach apparatus for attaching semiconductor dies on a substrate having a metal surface, which includes a material dispensing station for dispensing bonding material on the substrate, and a die attach station for placing semiconductor dies on bonding material that has been dispensed on the substrate. An activated gas generator positioned before the die attach station introduces activated synthesis gas onto the substrate to reduce oxides on the substrate.

EP 1393545 B1 describes a method and an apparatus for applying solder to a substrate, comprising melting a wire in a mixing chamber, and feeding the wire into a gas flow and moving or lowering two intermediate nozzles relative to the substrate in order to deposit solder blown from the nozzles on the substrate. The wire is fed into the mixing chamber in a conduit and the end of the wire is retracted into the conduit to interrupt the deposition process.

US 5065932 shows a nozzle assembly 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 fed into the bore to contact the elongate heat source. The bore terminates in a solder reservoir for molten solder fed within the bore to contact the elongate heat source. The molten solder is dispensed through the tip openings to deposit a uniform amount of solder on each pad. An exhaust gas source is supplied to the interior of the assembly to protect the component parts and to exhaust oxygen from the interior of the assembly. A cover gas is also supplied to the solder sites to mitigate oxidation of the molten solder and reduce the amount of flux required.

Generally, control of conventional solder dispensing processes requires complex and multiple functionalities, as well as multiple nozzles and air flows, to ensure that the solder melts or does not melt at a given location at a given timing. In addition, multiple streams and gas mixtures may further increase the complexity and cost of operation of the apparatus.

Disclosure of Invention

It is therefore an object of the present invention to provide a solder dispenser that provides additional functionality without increasing complexity.

According to the present invention, there is provided an apparatus for dispensing a bonding wire on a substrate, the apparatus comprising: a dispensing body; a dispensing passage for the bonding wire extending through the dispensing body, constructed and arranged to receive the bonding wire at a first end and dispense the bonding wire from a second end facing the substrate; and a first cooling chamber constructed and arranged to cool a region of the bonding wire with a first cooling gas in the distribution channel; wherein the first cooling chamber comprises at least one inlet for the first cooling gas, a line-facing outlet for the first cooling gas, and a distribution outlet for the first cooling gas, wherein the first cooling chamber is constructed and arranged to allow, in use, the first cooling gas to enter the first cooling chamber through the at least one inlet for the first cooling gas, to exit from the line-facing outlet for the first cooling gas away from the substrate, and to exit from the distribution outlet for the first cooling gas toward the substrate; and wherein the distribution channel for the bonding wire is contained within the first cooling chamber. By providing a direct flow of the first cooling gas to the bonding wire, unwanted variations in process results may be reduced and the dispensing apparatus may be less complex. The operating costs can also be reduced due to less gas consumption.

Drawings

Embodiments of the apparatus are designed and embodied in such a way that the first cooling chamber and the distribution channel for the bonding wire have similar or identical dimensions in one or more regions inside the distribution body. This may reduce mechanical complexity, weight, and/or volume by allowing a single structure (such as a single aperture) to be constructed as an important part of both the distribution channel and the cooling chamber.

A specific example of an apparatus is designed and embodied in such a way that the dispensing outlet has similar or identical dimensions to the second end of the dispensing channel. Additionally or alternatively, the outlet facing the wire has a similar or identical size as the first end of the dispensing channel. This may further reduce mechanical complexity, weight, and/or volume.

Embodiments of the apparatus are designed and embodied in such a way that the apparatus further comprises at least one auxiliary outlet for the first cooling gas, the auxiliary outlet being disposed outside the distribution body, constructed and arranged to allow, in use, at least a portion of the first cooling gas to flow from the first cooling chamber towards the substrate. This may enhance the effectiveness of the wire cooling, since the cooling effect may work even after the wire has left the apparatus.

Specific examples of the apparatus are designed and embodied in such a way that the first cooling gas comprises nitrogen, carbon dioxide, helium, neon, argon, krypton, hydrogen, carbon monoxide, or any combination thereof. This avoids or reduces oxidation of the substrate and its associated effects due to the cooling gas.

A specific example of the apparatus is designed and embodied in such a way that the first cooling gas comprises nitrogen and 5% to 20% hydrogen. This allows for reduced operating costs and provides a good protective atmosphere for the wires and substrate due to reduced substrate and wire oxidation.

A specific example of the apparatus is designed and embodied in such a way that the first cooling gas flowing through the distribution outlet has a flow rate in the range of 0.1 to 5 liters/min. This range of values allows for efficient cooling of the metal wire. In particular, additional thermal effects on the substrate may be reduced or avoided within this range.

A specific example of the apparatus is designed and embodied in such a way that the first cooling gas flowing through the outlet facing the line has a flow rate in the range of 0.1 to 5 liters/min. This range of values allows for efficient cooling of the wire while minimizing the cooling effect on the substrate.

A specific example of an apparatus is designed and embodied in such a way that the at least one inlet for the first cooling gas is arranged at an angle of less than 90 degrees in a counter-clockwise direction with respect to the longitudinal axis of the distribution body, if viewed from the longitudinal cross-section of the distribution body and the at least one inlet for the first cooling gas. This allows the first cooling gas to flow through the line-facing outlet and the distribution outlet in an optimal ratio, avoiding oxygen entering the nozzle while maintaining a high cooling effectiveness.

A specific example of an apparatus is designed and embodied in such a way that the at least one inlet for the first cooling gas is arranged at an angle of 30 degrees or more in a counter-clockwise direction with respect to the longitudinal axis of the distributor body, if viewed from the longitudinal cross-section of the distributor body and the at least one inlet for the first cooling gas.

A specific example of the apparatus is designed and embodied in such a way that, in 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 50 degrees celsius or more below the average melting point of the bonding wire. This prevents the wire inside the device from melting.

A specific example of an apparatus is designed and embodied in such a way that the apparatus further comprises a second cooling chamber constructed and arranged to cool a region of the distribution body by means of a second cooling gas, wherein the second cooling chamber comprises at least one inlet for the second cooling gas, at least one outlet for the second cooling gas, wherein the second cooling chamber is constructed and arranged to allow, in use, the second cooling gas to enter the second cooling chamber through the at least one inlet for the second cooling gas and to flow out of the at least one outlet for the second cooling gas. The second cooling chamber allows for more process settings for cooling. Depending on the material, it may be beneficial to the welding result if the second cooling is applied in addition to the first cooling or exclusively.

Embodiments of the apparatus are designed and embodied in such a way that the apparatus further comprises at least one auxiliary outlet for the second cooling gas, the auxiliary outlet being disposed outside the distribution body, constructed and arranged to allow, in use, the second cooling gas to flow from the second cooling chamber towards the substrate. This allows the second cooling gas to flow without affecting the process on the substrate.

Specific examples of the apparatus are designed and embodied in such a way that the second cooling gas comprises nitrogen, carbon dioxide, helium, neon, argon, krypton, hydrogen, carbon monoxide, oxygen, air, or any combination thereof.

A specific example of an apparatus is designed and embodied in such a way that the second cooling gas is identical to the first cooling gas. This may reduce mechanical and operational complexity.

Drawings

Other advantages and features of the present invention are derived from the following figures, namely:

Fig. 1A depicts a longitudinal cross section of an apparatus for dispensing wire bonds, which exhibits a first cooling function; and is also provided with

Fig. 1B depicts a longitudinal cross section of an apparatus for dispensing wire bonds, showing an optional second cooling function.

Detailed Description

Fig. 1A depicts a longitudinal cross-section of an apparatus 100 for dispensing wire bonds 200 on a substrate 500, which exhibits a first cooling function. For clarity, only the first cooling function is depicted. An optional second cooling function is depicted in fig. 1B, described in more detail below.

More particularly, fig. 1A depicts an apparatus 100 that includes a dispensing body 300 for wire 200 and a dispensing passage 400 that extends through the dispensing body 300. In other words, the dispensing passage 400 is contained within the dispensing body 300. The dispensing channel 400 is constructed and arranged to receive the bonding wire 200 at a first end 430 and dispense the bonding wire 200 from a second end 470 facing the substrate 500. Apparatus 100 may be constructed and arranged to operate with any suitable type of wire bond 200.

Apparatus 100 further includes a first cooling chamber 600 constructed and arranged to cool an area of wire 200 with a first cooling gas 810 within distribution channel 400. A distribution channel 400 for wire 200 is contained within first cooling chamber 600, which allows for the flow of first cooling gas 810 around wire 200 within the distribution body in use.

More particularly, the first cooling chamber 600 includes at least one inlet 630 for the first cooling gas 810, a line-facing outlet 651 for the first cooling gas 810, and a distribution outlet 652 for the first cooling gas 810.

Fig. 1A depicts a longitudinal cross-section of a distributor 300 and at least one inlet 630 for a first cooling gas 810.

The first cooling chamber 600 is constructed and arranged to allow, in use, a 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 flow away from the substrate 500 from the line-facing outlet 651 for the first cooling gas 810, and to flow out toward the substrate 500 from the distribution outlet 652 for the first cooling gas 810. This allows for providing a flow of the first cooling gas 810 around the wire bond 200 away from the substrate 500 and toward the area receiving the wire bond 200 for dispensing. In addition, this allows for providing a flow of the first cooling gas 810 around the bonding wires 200 in the area towards the substrate 500.

Apparatus 100 is constructed and arranged to provide a flow of a first cooling gas 810 around wire bond 200 during use. Optionally, it may be advantageous to provide for the flow of the first cooling gas 810 around the bonding wire 200 in substantially all of the distribution channels 400. Additionally or alternatively, it may be advantageous to provide a continuous flow of the first cooling gas 810 over a period of time. Alternatively, it may be advantageous to provide a pulsed flow of the first cooling gas 810 for a certain period of time.

During use, the first cooling gas 810 is connected to at least one inlet 630 for the first cooling gas 810, through which the first cooling gas enters the first cooling chamber 600 containing the distribution channel 400.

The first end 430 receiving the bonding 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 the distribution outlet 652 for the first cooling gas 810.

The distribution channel 400 extends from a first end 430 to a second end 470 in use proximate one or more regions of the wire 200. The cooling chamber 600 includes the distribution channel 400 by including one or more regions having a size greater than or equal to the size of the corresponding regions of the distribution channel 400.

Optionally, it may be advantageous for apparatus 100 to be constructed such that first cooling chamber 600 and dispensing passage 400 for bonding wire 200 have similar or identical dimensions in one or more areas inside dispensing body 300. For example, as depicted in fig. 1A and 1B, a single structure, such as a single hole through the distributor 300, may be constructed and arranged as a significant portion of both the cooling chamber 600 and the distribution channel 400. This may reduce mechanical complexity, weight, and/or volume.

Additionally or alternatively, the dispensing outlet has similar or identical dimensions to the second end of the dispensing channel. Additionally or alternatively, the outlet facing the wire has a similar or identical size as the first end of the dispensing channel. This may further reduce mechanical complexity, weight, and/or volume.

The flow of the first cooling gas 810 into the distribution channel 400 splits into two main flows around the weld line 200: a first main flow 8101 towards the substrate 500, which exits the distribution channel 400 at the second end 470 of the distribution channel 400, and a second main flow 8102 away from the substrate 500, which exits the distribution channel 400 at the first end 430 of the distribution channel 400.

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

The second primary flow 8102 may be further advantageous in that it allows the apparatus 100 to be constructed and arranged to provide a first cooling gas 810 around the bonding wire 200 in substantially all of the distribution channels 400.

For example, the apparatus 100 may be constructed and arranged to provide, in use, a first main flow 8101 in the range of 0.1 to 5 liters per minute (l/min) for the first cooling gas 810 flowing through the distribution outlet 652.

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

Apparatus 100 may be constructed and arranged for use in a soldering process in which wire bonds 200 are to be provided to a substrate 500, such as a leadframe. Optionally, during or after dispensing, the dispensed solder 250 may be pressed and/or stamped (optionally with another device) to provide a larger surface area. Optionally, a predetermined and/or controlled shape, such as a rectangle or square, may be formed. The die may then be bonded to the upper surface of the dispensed solder 250. The result is an intermetallic bond between the leadframe substrate 500 and the die. Typically, the soldering process is performed at a temperature of approximately 380 degrees celsius (c).

The present invention is based at least in part on the following insight: conventional dispensing devices that rely on indirect cooling are inefficient. If a cooling gas is provided that is not in direct contact with the wire, cooling is considered indirect. In other conventional apparatus in which the synthesis gas is to be applied, a separate gas distribution system, typically with a dedicated gas outlet, is used to deliver the synthesis gas near the solder on the substrate surface 500 during and/or after dispensing.

Due to the higher cooling efficiency, it may be advantageous to provide a configurable flow of the first cooling gas 810 around the bond wire 200. This may reduce process parameter variations, which in turn provides a more consistent and repeatable dispensed solder 250. Consistency and/or repeatability may be assessed, for example, by using one or more characteristics such as: shape, size, curvature, volume, area, wetting angle, absolute position on the substrate 500, relative position on the substrate 500, or any combination thereof.

The present invention is also based at least in part on the following insight: in conventional dispensing apparatus that rely on indirect cooling, relatively high flows are required to provide stable and reliable dispensing in a controlled manner. Higher airflow settings are required, such as greater than 20 liters per minute (l/min), which may increase operating costs.

In addition, many conventional devices primarily use gas flow to reduce the risk of oxidation in areas near the substrate. However, the invention is also based at least in part on the following insight: it is further advantageous to cool wire 200 directly in distribution channel 400.

Generally, those conventional dispensing apparatus and dispensing nozzles are relatively complex, making them expensive to manufacture. The inventors have determined experimentally that, in the case of operation at relatively high flow rates, those complex equipment may exhibit undesirable indirect cooling gas leakage. Conventionally, those of ordinary skill in the art have attempted to reduce unwanted leakage by, for example, reducing dimensional tolerances and/or mechanical stresses in the mechanical parts of the equipment and sealing with high temperature ceramic paste.

By providing a direct flow of the first cooling gas 810 to the bond wire 200 according to the present invention, unwanted variations in the process results may be reduced.

In some apparatus 100, the desired flow of the first cooling gas 810 may be reduced. In some apparatus 100, this may reduce operating costs by reducing cooling gas consumption. This may also reduce the complexity of the solder dispensing apparatus 100.

In some apparatus 100, the weight and/or volume of the solder dispensing apparatus 100 may be reduced.

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

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

Optionally, the apparatus may be constructed and arranged to provide the first cooling gas 810 such that in at least a portion of the first cooling chamber 600, the average temperature is predetermined and/or controlled to be 50 ℃ or more below the average melting point of the wire bonds 200. For example, the apparatus 100 may further include one of a plurality of coolers (not depicted) that are located in a non-stationary manner or in close proximity to at least one inlet 630 for the first cooling gas 810. For example, the melting point temperature of the solder 200 is typically in the range of 300 ℃ to 400 ℃. In some specialized processes, the melting point temperature may be as high as 1000 ℃.

It may also be advantageous to provide the first cooling gas 810 such that the average temperature is predetermined and/or controlled to be 50 ℃ or more below the average melting point of the bonding wire 200 in substantially all of the distribution channels 400.

Optionally, the first cooling gas 810 may be provided such that in the region proximate to the dispensing outlet 652, the average temperature is predetermined and/or controlled to be 50 ℃ or more below the average melting point of the bonding wire 200.

For example, in the case of dispensing wire bonds 200 having a melting point in the range of 300 ℃ to 400 ℃, the first cooling gas 810 may be provided such that the average temperature is predetermined and/or controlled to be in the range of 100 ℃ to 150 ℃ when measured substantially 1mm away from the dispensing outlet 652 in the idle mode.

Fig. 1B depicts a longitudinal cross-section of apparatus 100, which shows a second optional cooling function. The apparatus 100 depicted in fig. 1B is the same as that depicted in fig. 1A and described with respect to fig. 1A, however, for clarity reasons, several features depicted in fig. 1A are not depicted in fig. 1B. This second optional cooling function is indirect and constructed and arranged to operate concurrently with the first cooling function.

In particular, fig. 1B depicts an apparatus 100 that includes a second cooling chamber 700 constructed and arranged to cool a region of the distribution body 300 with a second cooling gas 820.

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 depicts two outlets 750 for the second cooling gas 820. Optionally, a modified mechanical configuration may be used to provide only one outlet 750 for the second cooling gas 820.

Thus, fig. 1B depicts a longitudinal cross-section of the distributor 300, at least one inlet 630 for a first cooling gas (not indicated), at least one inlet 730 for a second cooling gas 820, and two outlets 750 for the second cooling gas 820. FIG. 1B depicts one example-it should be recognized by one of ordinary skill in the art that the inlet and outlet need not be disposed within the same longitudinal cross-section.

The second cooling chamber 700 is constructed and arranged to allow, in use, a second cooling gas 820 to enter the second cooling chamber 700 through the at least one inlet 730 for the second cooling gas 820 and to flow out of the at least one outlet 750 for the second cooling gas 820.

Optionally, the second cooling gas 820 flowing out of the at least one outlet 750 may be directed away from the substrate 500.

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

The second cooling function is optionally employed. Which may be configured differently than the first cooling function. Alternatively, the second cooling function may be constructed and arranged to cooperate with the first cooling function to achieve a desired degree of cooling.

The first cooling function may be configured and arranged differently from the second cooling function, if desired. Alternatively, if an optional second cooling function is provided, the first cooling function may be constructed and arranged to cooperate with the second cooling function to achieve a desired degree of cooling.

As depicted in fig. 1A and described above, the first cooling function includes a flow of the first cooling gas 810 into the distribution channel 400 that is divided into a first main flow 8101 toward the substrate 500 and a second main flow 8102 away from the substrate 500.

As depicted in fig. 1A, if viewed from a longitudinal cross-section of the distributor 300 and the at least one inlet 630 for the first cooling gas 810, the apparatus 100 may optionally be further constructed and arranged to position the at least one inlet 630 for the first cooling gas 810 at an angle 950 of less than 90 degrees in a counter-clockwise direction relative to the longitudinal axis 900 of the distributor 300. The symmetry axis 920 of the at least one inlet 630 may be used to determine the angle 950 of the at least one inlet 630. This angle 950 may be predetermined and/or controlled to modify the flow ratio between the first primary flow 8101 toward the substrate 500 and the second primary flow 8102 away from the substrate 500.

For example, an angle 950 in the range between 30 degrees and 90 degrees may be advantageous.

For example, an angle 950 in the range between 70 degrees and 90 degrees may be more advantageous.

The predetermined and/or controlled such angle 950 may modify a ratio between the first main flow 8101 towards the substrate 500 and the second main flow 8102 away from the substrate 500. For example, at an angle 950 of approximately 90 degrees, the ratio may be approximately 1:1. For example, reducing the angle 950 to substantially less than 90 degrees may relatively increase the first main flow 8101 toward the substrate 500 while maintaining a sufficient volume of the second main flow 8102 to reduce the risk of environmental contamination through openings (such as the wire-facing outlets 651) into at least a portion of the distribution channel 400.

The inventors have determined that using direct cooling (first cooling function) according to the present invention can provide at least a considerable degree of process quality compared to conventional methods using only indirect cooling.

For such measurements, the apparatus 100 as depicted in FIGS. 1A and 1B is implemented by modifying a line distributor apparatus of a conventional type suitable for use in a soldering process. The conventional indirect cooling function of the conventional wire distributor apparatus is constructed and arranged as the second cooling function depicted in fig. 1B and described in the present invention. A direct cooling function is added to the line distributor apparatus and is constructed and arranged as the first cooling function depicted in fig. 1A and described in the present disclosure.

A specific example of a line distributor apparatus may include an inlet distributor 670 for a first cooling gas 810 that is connected to the distribution channel 400 in a non-stationary manner. In this example, the first cooling chamber 600 and the distribution channel 400 may have similar or identical dimensions in one or more regions inside the distribution body 300.

If viewed from the longitudinal cross-section of the distributor body 300 and the at least one inlet 630 for the first cooling gas 810, a specific example of a line distributor apparatus may be disposed at an angle 950 of approximately 70 degrees in a counter-clockwise direction relative to the longitudinal axis 900 of the distributor body 300 for the at least one inlet 630 of the first cooling gas 810.

Specific examples of wire dispenser devices may retain the original dispensing passage 400 having an average pore size of 0.4 to 1.2mm for use with wire bonds 200 having an average diameter in the range of 0.2 to 1.0 mm.

To measure relative performance, representative process results are selected for comparison: the average volume of solder dispensed in cubic millimeters (mm 3) is calculated as the standard deviation divided by the change in average volume in percent (%) and the amount of line slippage in micrometers (μm).

Both the first (direct) and second (indirect) cooling functions were connected using flow regulators to study the effect of different flow schemes. It is assumed that the measurements (measurements numbered 01 to 03) obtained with the flow through the second cooling function only are acceptable approximations of the operation using the conventional line distributor apparatus without modification.

Measurement results (table 1):

The measurement results 01 to 03 were obtained using the second cooling function only with indirect cooling as acceptable approximations for the case of using the conventional wire distribution apparatus. The measurement result 01 can be considered to represent standard operating conditions for a soft solder process using conventional wire dispensing equipment.

In contrast, the measurement result 04 is obtained by the first cooling function with a lesser degree of indirect cooling and direct cooling.

In contrast, measurements 05 to 11 were obtained using direct cooling only.

The measurements of Table 1 show that if the indirect cooling flow rate varies from the typical rate of 25l/min provided by measurement 01 to the typical rate of 3l/min provided by measurement 03, a significant increase (deterioration) to 2.72% in the variation is observed at the indirect cooling flow rate of 3l/min provided by measurement 03. This corresponds to a reduction in indirect flow rate of approximately 90% compared to the standard operating conditions for measurement 01.

If the indirect cooling is reduced to 1l/min, the direct cooling is reduced to 0.5l/min as provided by measurement 04, and the variation is also reduced to 1.51%, which is comparable to the standard operating conditions of measurement 01, the reduction in variation indicates a direct improvement.

If the direct cooling rate is increased to 0.8l/min, a decrease in the change to 1.3% is observed at measurement 05, which is a lower change that can be measured according to the standard operating conditions of measurement 01, and the decrease in the change indicates a direct improvement.

In the case of direct cooling flow rates of only 0.6l/min as can be observed at measurements 06, 07, 09, these measurements showed some variation fluctuations of 1.61% to 1.71%.

In the case of direct cooling flow rates of only 0.5l/min as can be observed at measurements 10 and 11, these measurements showed some variation fluctuations of 1.75% to 1.88%. Further improvement in process quality is expected in cases where indirect cooling is used in addition to direct cooling, as compared to measurement 04, which provides additional indirect cooling of 1 l/min.

Measurements 04 and 05 show slightly improved levels of variation compared to the standard operating conditions of measurement 01, but with lower overall gas usage. In particular, for measurement result 04 with direct cooling of 0.5l/min and indirect cooling of 1l/min, the overall usage was 1.5l/min, which was 94% lower than measurement result 01. In particular, for measurement result 05 with direct cooling only at 0.8l/min, the overall usage was 0.8l/min, which was a reduction in usage of approximately 95% compared to measurement result 01.

In addition, one of ordinary skill in the art will recognize that the amount of wire slippage remains relatively unchanged during direct cooling only, combined direct and indirect cooling, and indirect cooling only.

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

By following the instructions provided in the present disclosure, one or more embodiments of the wire dispensing apparatus 100 including the direct cooling flow of the first cooling gas 810 may be optimized to further improve the solder dispensing process. For example, it may be advantageous to optimize embodiments to improve protection of the bond wire 200 during use and to increase the degree of cleanliness of the bond wire 200 from oxides that may be present.

Additionally or alternatively, it may be advantageous to optimize one or more embodiments such that wire 200 has less friction and less slippage in dispensing channel 400. In this example, wire bond 200 may be considered to be included in a gas bearing system due to distribution channel 400 being filled with first cooling gas 810.

Additionally or alternatively, it may be advantageous to optimize one or more embodiments to have less clogging of wire 200 by draining solder particles and/or other contaminants from dispensing outlet 652.

Additionally or alternatively, it may be advantageous to optimize one or more embodiments to achieve less cleaning of the distribution channel 400 by draining solder particles and/or other contaminants through the wire-facing outlet 651 and/or the distribution outlet 652.

Additionally or alternatively, it may be advantageous to optimize one or more embodiments to provide more reliable and repeatable dispensed solder by: optimizing for lower wetting angles below 40 degrees, preferably below 35 degrees, and most preferably below 30 degrees; and/or for reduced volume variation of the dispensed solder volume of less than about 5% standard deviation, preferably less than about 2% standard deviation, and most preferably less than about 1% standard deviation.

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

Optionally, the apparatus 100 may further include at least one auxiliary outlet (not depicted) for the first cooling gas 810, disposed outside the distribution body 300. This may be constructed and arranged to allow at least a portion of the first cooling gas 810 to flow from the first cooling chamber 600 toward the substrate 500 in use.

The at least one auxiliary outlet may be further constructed and arranged to direct at least a portion of the first cooling gas 810 toward the substrate 500 at an angle that is: substantially parallel to the longitudinal axis 900 of the dispensing body 300, with no deviation from this axis or with a minimum deviation of less than 1.0 degrees or less than 2.0 degrees; significantly non-parallel to the longitudinal axis 900, at a non-zero angle to the longitudinal axis 900; or any combination thereof. In some configurations, it may be advantageous to direct at least a portion of the first cooling gas 810 toward the substrate 500 at an angle that: substantially perpendicular to the longitudinal axis 900. These are angles seen from a longitudinal cross-sectional view of the distributor 300 and at least one auxiliary outlet for the first cooling gas 810. Preferably, at least one auxiliary outlet is disposed in one or more locations, disposed concentrically and symmetrically laterally with respect to the longitudinal axis 900. In other words, the configuration may be similar to a "shower head" for the first cooling gas 810 when the second end 470 of the solder dispensing channel 400 is viewed from the substrate 500. This may provide one or more substantially concentric flow areas of the first cooling gas 810 around the line 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.

Specific examples may also be considered advantageous, either by themselves or in combination with one or more other examples.

For example, it may be advantageous to modify a conventional distribution channel (such as a wire distribution apparatus) by adding at least one inlet for the first cooling gas 810 that is connected to the original distribution channel and/or the wire capillaries in a non-fixed manner.

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

For example, it may be advantageous to provide one or more perforations between the at least one inlet 630 for the first cooling gas 810 and the distribution channel 400 to predetermine a substantial amount of flow within the distribution chamber 400. The perforations may be arranged in any suitable configuration and configuration-for example, a plurality of perforations may be provided in the inlet distributor 670 (as depicted in fig. 1A). Preferably, inlet distributor 670 is constructed and arranged to provide substantially all flow around the outside of wire 200.

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

For example, it may be advantageous to provide one or more flow meters to measure the intensity of at least a portion of one or more flows of the second cooling gas 820.

[ Symbolic description ]

Reference numerals	Definition of the definition
		100	Wire distribution device
200	Bonding wire
		250	Solder material dispensed
300	Dispensing body
		400	Bonding wire distribution channel
430	First end of solder dispensing passage
		470	Second end of solder dispensing passage
500	Substrate board
		600	First cooling chamber
630	Inlet for a first cooling gas
		651	Line-facing outlet for a first cooling gas
652	Distribution outlet for a first cooling gas
		670	Inlet distributor for a first cooling gas
700	Second cooling chamber
		730	Inlet for a second cooling gas
750	Outlet for a second cooling gas
		810	First cooling gas
8101	A first main flow (toward the substrate) of a first cooling gas
		8102	A second main flow (away from the substrate) of the first cooling gas
820	Second cooling gas
		900	Longitudinal axis
920	Symmetry axis of the first cooling gas inlet
		950	Angle of air inlet

Claims

1. An apparatus (100) for dispensing a bonding wire (200) on a substrate (500), the apparatus (100) comprising:

A dispensing body (300);

A dispensing passage (400) for the bonding wire (200) extending through the dispensing body (300), constructed and arranged to receive the bonding wire (200) at a first end (430) of the dispensing passage (400) and dispense the bonding wire (200) from a second end (470) of the dispensing passage (400) facing the substrate (500); and

A first cooling chamber (600) constructed and arranged to cool a region of the wire (200) with a first cooling gas (810) within the distribution channel (400);

Wherein the first cooling chamber (600) comprises at least one inlet (630) for the first cooling gas (810), a line-facing outlet (651) for the first cooling gas (810), and a distribution outlet (652) for the first cooling gas (810), wherein 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 flow away from the substrate (500) from the line-facing outlet (651) for the first cooling gas (810), and to flow toward the substrate (500) from the distribution outlet (652) for the first cooling gas (810); and is also provided with

Wherein the distribution channel (400) for the bonding wire (200) is contained within the first cooling chamber (600).

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

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

4. The apparatus of any of the preceding claims, the apparatus (100) further comprising at least one auxiliary outlet for the first cooling gas (810) disposed outside the distribution body (300), constructed and arranged to allow, in use, at least a portion of the first cooling gas (810) to flow from the first cooling chamber (600) towards the substrate (500).

5. The apparatus of any of the preceding claims, 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 any of the preceding claims, wherein the first cooling gas (810) comprises nitrogen and 5% to 20% hydrogen.

7. The apparatus of any of the preceding claims, wherein the first cooling gas (810) flowing through the distribution outlet (652) has a flow rate in the range of 0.1 to 5 liters/min.

8. The apparatus of any of the preceding claims, wherein the first cooling gas (810) flowing through the wire-facing outlet (651) has a flow rate in the range of 0.1 to 5 liters/min.

9. The apparatus of any of the preceding claims, wherein the at least one inlet (630) for the first cooling gas is arranged at an angle (950) of less than 90 degrees in a counter-clockwise direction with respect to the longitudinal axis (900) of the distribution body (300) if viewed from a longitudinal cross-section of the distribution body (300) and the at least one inlet (630) for the first cooling gas (810).

10. The apparatus of claim 9, wherein the at least one inlet (630) for the first cooling gas is disposed at an angle (950) of 30 degrees or more in a counter-clockwise direction relative to the longitudinal axis (900) of the distribution body (300) if viewed from a longitudinal cross-section of the distribution body (300) and the at least one inlet (630) for the first cooling gas (810).

11. The apparatus of any of the preceding claims, wherein, in use, an 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 50 degrees celsius or more below an average melting point of the bonding wire (200).

12. The apparatus of any of the preceding claims, the apparatus (100) further comprising a second cooling chamber (700) constructed and arranged to cool a region of the distribution body (300) by means of a second cooling gas (820), wherein the second cooling chamber (700) comprises at least one inlet (730) for the second cooling gas (820) and at least one outlet (750) for the second cooling gas (820), wherein the second cooling chamber (700) is constructed and arranged to allow, in use, the second cooling gas (820) to enter the second cooling chamber (700) through the at least one inlet (730) for the second cooling gas (820) and to flow out of the at least one outlet (750) for the second cooling gas (820).

13. The apparatus of claim 12, the apparatus (100) further comprising at least one auxiliary outlet for the second cooling gas (820) disposed outside the distribution body (300), constructed and arranged to allow, in use, the second cooling gas (820) to flow from the second cooling chamber (700) toward the substrate (500).

14. The apparatus of claim 12 or 13, 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 or 13, wherein the second cooling gas (820) is the same as the first cooling gas (810).