WO2018132532A1

WO2018132532A1 - Wave and selective soldering apparatus and method using a slot soldering nozzle and at least one selective soldering nozzle within a solder pot

Info

Publication number: WO2018132532A1
Application number: PCT/US2018/013261
Authority: WO
Inventors: Mark DAGELINCKX; Michael Cable
Original assignee: Nordson Corporation
Priority date: 2017-01-16
Filing date: 2018-01-11
Publication date: 2018-07-19
Also published as: WO2018132532A8

Abstract

The present application relates to a method and to an apparatus for applying molten solder to a substrate are disclosed. A soldering machine for applying solder to a substrate includes at least one slot soldering nozzle (28) configured to apply a wave of molten solder across substantially the entire surface of a substrate in one or more passes across the substrate, at least one selective soldering nozzle (32a, 32b) configured to apply molten solder selectively to individual component pins or groups of component pins exposed on a substrate, and a solder pot for containing the molten solder for use by both types of nozzles (28; 32a, 32b).

Description

WAVE AND SELECTIVE SOLDERING APPARATUS AND METHOD USING A SLOT SOLDERING NOZZLE AND AT LEAST ONE SELECTIVE SOLDERING NOZZLE

WITHIN A SOLDER POT

CROSS REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit of U.S. Provisional Patent App. No.

62/446,674, filed January 16, 2017, the disclosure of which is incorporated by reference herein.

TECHNICAL FIELD

[0002] The present invention generally relates to a soldering machine for applying molten solder to a substrate, and more particularly relates to a soldering machine capable of performing both wave soldering and selective soldering.

BACKGROUND

[0003] Known wave soldering machines solder a number of components to a substrate, such as a printed circuit board (PCB), as the PCB is conveyed over a wave of solder. The wave soldering machine may comprise a solder bath configured to generate a "wave" of molten solder over which a PCB is floated to typically completely solder the underside of the PCB. The molten solder may be supplied from a vessel or container filled with the molten solder. The wave of molten solder is generated by pumping the molten solder from the solder pot through the slot soldering nozzle.

[0004] Wave soldering machines are advantageous in that they can create solder connections between the pins of multiple components on the PCB and the holes through the PCB into which the pins are received in a single pass of the PCB over the wave. However, the wave soldering machine is not useful for applications where single pins of a component, or groupings of pins, are to be soldered selectively. In addition, the substrate itself or certain components on the substrate may be damaged by the high temperatures associated with wave soldering.

[0005] Selective soldering machines, in contrast to wave soldering machines, may be configured to apply molten solder to individual pins of a component on a substrate, or groups of pins, without disturbing other components that need not be soldered or cannot withstand, for example, the heat producing effects of wave soldering machines. With selective soldering, a small fountain (e.g., column) of solder is formed using a nozzle that is oriented vertically, and that nozzle and the fountain of solder is raised to engage the PCB hole through which the pin of a component extends, or grouping of pins/holes extend.

[0006] For manufacturers of PCBs, it is often necessary, therefore, to buy two separate machines - one capable of wave soldering and one capable of selective soldering - to meet the soldering needs of a variety of different substrates. The present invention obviates this need by envisioning a single machine that can be used to perform both wave soldering and/or selective soldering, as needed.

SUMMARY

[0007] Methods and systems are disclosed herein for applying molten solder to a substrate. In one aspect, a soldering machine for applying solder to a substrate may comprise at least one wide slot soldering nozzle configured to apply a wave of molten solder across a substantial portion of a first substrate, at least one selective soldering nozzle configured to selectively apply molten solder to an individual pin of a component (or group of pins), and a solder pot for containing the molten solder, where the solder pot is in fluid communication with both the slot soldering nozzle and the selective soldering nozzle.

[0008] The slot soldering nozzle preferably rides on top of the solder pot and moves in the x-y-z directions with the solder pot, while the selective nozzle preferably moves only in the x-y directions with the solder pot and is independently movable in the z direction (i.e. vertically) with respect to the solder pot. Independent vertical movement of the selective soldering nozzle can be implemented, for example, by using an air cylinder on the outside of the solder bath that is connected to a bracket that extends up along the side of solder bath, across the top of the solder bath and then down into the solder bath to be connected to the nozzle, and/or the pump (later described), which can be rigidly attached to the nozzle. In addition, preferably, the top edge of the slot nozzle is positioned above the top edge of the selective soldering nozzle when the selective soldering nozzle is in its down position, and the top edge of the selective soldering nozzle can be raised to above the top edge of the slot nozzle when the selective soldering nozzle is in its up position. This prevents the nozzle that is not being used from contacting the PCB while the other nozzle is applying solder.

[0009] In an aspect, the soldering machine comprises one or more pumps configured to move molten solder from the solder pot to at least one of the slot soldering nozzle and the selective soldering nozzle. The pump may comprise a first pump configured to move molten solder from the solder pot to the slot soldering nozzle and a second pump configured to move molten solder from the solder pot to the selective soldering nozzle. As mentioned, the second pump can be rigidly connected to the selective soldering nozzle and connected by a bracket to any other cylinder, for example, to reciprocate the second pump and nozzle towards and away from the substrate.

[0010] In one embodiment, the solder pot may be in fluid communication with one slot soldering nozzle and two selective soldering nozzles. The two selective soldering nozzles may comprise a first selective soldering nozzle with an aperture having a first size or shape and a second selective soldering nozzle having a second size or shape that is different from the first nozzle. The soldering machine may further comprise a first pump configured to move molten solder from the solder pot to the first selective soldering nozzle, a second pump configured to move molten solder from the solder pot to the second selective soldering nozzle, and a third pump configured to move molten solder from the solder pot to the slot soldering nozzle. The wave of molten solder may be generated by pumping the molten solder from the solder pot through the slot shaped orifice of the slot soldering nozzle using the third pump. The slot shaped nozzle is preferably fixed in position relative to the solder pot and the solder pot is preferably movable in a direction towards and away the first substrate such that the wave of molten solder can be placed into contact with the surface of the first substrate. Preferably the slot nozzle is moved across the first substrate in one or more passes to solder the entire substrate.

[0011] In some aspects, the soldering machine may comprise a barcode reader configured to read a barcode located on at least one of a first substrate or a second substrate. The barcode may encode a soldering program used by a soldering machine controller to utilize the slot soldering nozzle and/or one or more selective soldering nozzles to solder components to the substrate.

[0012] Various additional features and advantages of this invention will become apparent to those of ordinary skill in the art upon review of the following detailed description of the illustrative embodiments taken in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] The following detailed description is better understood when read in

conjunction with the appended drawings. For the purposes of illustration, examples are shown in the drawings; however, the subject matter is not limited to the specific elements and

instrumentalities disclosed. In the drawings:

[0014] FIG. 1 illustrates a schematic of an example soldering machine that can be used with the present invention;

[0015] FIG. 2 illustrates an alternate view of the soldering machine of FIG. 1;

[0016] FIG. 3 illustrates a schematic of an example soldering machine comprising a slot soldering nozzle and a selective soldering nozzle according to an embodiment of the present invention;

[0017] FIG. 4 illustrates exemplary rectangular selective soldering nozzles that can be used with the present invention;

[0018] FIG. 5 illustrates exemplary circular selective soldering nozzles that can be used with the present invention;

[0019] FIG. 6 illustrates a schematic of an example soldering machine comprising a slot soldering nozzle and two selective soldering nozzles according to an embodiment of the present invention;

[0020] FIG. 7 illustrates a soldering mechanism comprising a slot soldering nozzle and two selective soldering nozzles according to an embodiment of the present invention;

[0021] FIG. 8 illustrates a soldering mechanism comprising a slot soldering nozzle and two selective soldering nozzles according to an embodiment of the present invention;

[0022] FIG. 9 illustrates another view of the soldering mechanism shown in FIG. 8; and

[0023] FIG. 10 illustrates a top view of the soldering mechanisms shown in FIGS. 8 and 9.

DETAILED DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS

[0024] With reference to FIGS 1 and 2 generally, and more particularly with reference to FIG 3, a soldering machine 10 includes at least one slot soldering nozzle 28 and at least one selective soldering nozzle 32 positioned above a solder pot 22 of molten solder 24. Slot nozzle 28 is supplied by solder pump 30 and solder nozzle 32 is applied by solder pump 34. Preferably, the soldering machine 10 applies a wave of molten solder across the entire underside of a first substrate using the slot soldering nozzle 28, and selectively applies molten solder individually to one or more predetermined pins extending through the underside of a second substrate using the selective soldering nozzle 32. As will be described in further detail below, the single soldering machine 10 can be used to perform both wave soldering and selective soldering.

[0025] The soldering machine 10, as shown in FIG. 1, may comprise a conveyor mechanism 12 for moving the substrate through the soldering machine 10. The conveyor mechanism 12 may be, for example, a dual-lane conveyor mechanism. The substrate 20 may be placed onto the conveyor mechanism 12 at a loading point of the conveyor mechanism 12, and the conveyor mechanism 12 may be configured to move the substrate 20 from one location to another location within the soldering machine 10. The conveyor mechanism 12 may be configured to hold the substrate in place, for example, in the soldering zone 19 (later described) as one or more of the soldering nozzles are moved into contact with the substrate 20. In one embodiment, the conveyor mechanism 12 may comprise multiple conveyor mechanisms. For example, a first conveyor mechanism may move the substrate from the loading point to a fluxer 14, a second conveyor mechanism may move the substrate from the fluxer 14 to a preheating mechanism 16, 18, etc. In one embodiment, in addition to or in place of the conveyor mechanism 12, the soldering machine 10 may comprise a gripping mechanism configured to move the substrate from one location to the next, and to hold the substrate 20 in place in the soldering zone 19 while solder is applied to the substrate 20.

[0026] As shown schematically in Figure 3, the soldering machine may comprise a number of stages, zones, or stations, such as a fluxing stage, or fluxer 14, top preheat stage 16, bottom preheat stage 18, soldering zone 19, inspection station 36 and cooling station 38. As shown in FIG. 1, the fluxer 14 may be an xy-fluxer configured to spray or wet flux onto a substrate in both the x-direction and the y-direction. The fluxer 14 may be a spray fluxer, a drop- jet fluxer, and/or an atomizing fluxer. In the example shown in FIG. 1, the fluxer 14 is a spray fluxer configured to spray chemical suspensions mixed with water on the substrate 20. The fluxer 14 may also be configured to clean the components of the substrate 20 before the substrate is soldered. For example, any impurities, such as the forming of oxide layers on the substrate, can affect the soldering process which may then lead to poor quality solder joints. From the fluxer 14, the substrate 20 is conveyed to a preheating mechanism. [0027] The topside preheating mechanism 16 may be used to preheat a top surface of the substrate 20 and a bottom side preheating mechanism 18 may be used for preheating a bottom surface of the substrate 20. The conveyor mechanism 12 may be configured to move the substrate 20 from the topside preheating mechanism 16 to the bottom side preheating mechanism 18. The topside preheating mechanism 16 and the bottom side preheating mechanism 18 may each comprise one of an infrared (IR) preheater, a quartz tube radiator or a convection heating mechanism.

[0028] In one embodiment, the topside preheating mechanism 16 and the bottom side preheating mechanism 18 may be a single preheating mechanism configured to heat both a top side and a bottom side of the substrate 20. In another embodiment, the topside preheating mechanism 16 and the bottom side preheating mechanism 18 may comprise two separate heating mechanisms. In a further embodiment, the topside preheating mechanism 16 and the bottom side preheating mechanism 18 may comprise two different types of preheating mechanisms. For example, the topside preheating mechanism 16 may comprise a quartz tube radiator and the bottom side preheating mechanism 18 may comprise an IR heating mechanism.

[0029] Preheating the substrate may help accelerate the soldering process and may also prevent thermal shock to the one or more exposed components on the substrate 20 to be soldered. The preheating mechanism may further comprise a temperature sensor for detecting a

temperature of the substrate. After the substrate has been preheated to a desired temperature, for example, as indicated by instructions in a computer program, the conveyor mechanism 12 may be configured to move the substrate 20 from the preheating mechanism to the soldering zone 19. While in the soldering zone 19, the substrate may be kept at a pre-determined temperature by a second topside preheating component, such as topside preheating mechanism 15 illustrated in FIG. 1.

[0030] As shown in FIG. 3, the substrate 20 may be moved into the soldering zone 19 for application of molten solder to the substrate 20. The soldering zone 19 may comprise a position correcting device (not shown) to position the substrate 20 in a correct position on the conveyor mechanism 12 for soldering. The soldering zone 19 defines an area where molten solder may be applied to the substrate 20 by any of the at least one slot soldering nozzle 28 or the at least one selective soldering nozzle 32, as discussed further herein. [0031] The substrate 20 may be any type of substrate. For example, the substrate 20 may be an electronic assembly, such as a printed circuit board (PCB). One or more surfaces of the PCB may comprise a plurality of electrical components having pins extending through holes in the PCB that, when contacted by molten solder, for example, by one of the slot soldering nozzle 28 or the selective soldering nozzle 32, become soldered to the PCB. In one embodiment, the substrate may be a minimum of 50mm x 50mm. In another embodiment, the PCB may have a maximum size of 400mm x 400mm. However, it is understood that the substrate may be of any size.

[0032] As mentioned above, the soldering machine 10 includes a solder pot 22 for containing the molten solder 24. The solder pot is in fluid communication with both the slot soldering nozzle 28 and the selective soldering nozzle 32. The solder pot may comprise a warming device (not shown) to control the temperature of the molten solder 24 contained in the solder pot 22. As discussed further below, the solder pot 22 may be moved in any of the x- direction, y-direction or z-direction such that one or more of the slot soldering nozzle 28 or selective soldering nozzle 32 may be moved in a direction toward or away from the substrate.

[0033] In the preferred embodiment, during use the slot soldering nozzle 28 is fixed in position with respect to, and move with, the solder pot 22, while the selective soldering nozzle is reciprocated up and down with respect to the solder pot 22. In this embodiment, when the slot soldering nozzle 28 is used, the entire solder pot 22 is moved upwardly to place the solder wave from the slot soldering nozzle 28 into contact with the underside of the PCB 20, whereas when the selective soldering nozzle 32 is used, the solder pot 22 is not moved upwardly and instead the selective soldering nozzle 32 is raised into contact with the underside of the PCB 20 and then lowered back down after making contact. Independent vertical movement of the selective soldering nozzle 32 can be implemented, for example, by using an air cylinder on the outside of the solder bath that is connected to a bracket that extends up along the side of solder bath, across the top of the solder bath and then down into the solder bath to be connected to the nozzle, and or the pump, which can be rigidly attached to the nozzle.

[0034] Preferably, the top edge of the slot soldering nozzle 28 is positioned above the top edge of the selective soldering nozzle 32 when the selective soldering nozzle 32 is in its down position, and the top edge of the selective soldering nozzle 32 can be raised to above the top edge of the slot soldering nozzle 28 when the selective soldering nozzle 32 is in its up position. This prevents the nozzle that is not being used from contacting the PCB while the other nozzle is applying solder. In an alternate embodiment, the slot soldering nozzle would be moved between an up and a down position, and the selective soldering nozzle would be maintained in a fixed position with respect to the soldering pot. In that case, the top edge of the selective soldering nozzle 28 would be located below the top edge of the slot soldering nozzle 32 when the slot soldering nozzle 28 is in the down position, and the top edge of the slot soldering nozzle 28 would be above the top edge of the selective soldering nozzle 32 when the slot soldering nozzle 28 is in the up position. In this embodiment, the slot soldering nozzle would move in x-y with the solder pot, and independently in z with respect to the soldering pot, and the selective soldering nozzle would move in x-y-z with the soldering pot. In one embodiment, the molten solder 24 may comprise molten lead, molten tin, or a combination of the two. However, it is understood that the solder is not limited to these elements.

[0035] The solder pot 22 is connected to an x-y-z movement mechanism 26. Moving the solder pot 22 in the x-direction refers to moving the solder pot 22 in a direction along the axis of the conveyor mechanism 12. Moving the solder pot 22 in the y-direction refers to moving the solder pot 22 in a direction transverse to the axis of the conveyor mechanism and perpendicular to the x-direction. Moving the solder pot in the z-direction refers to moving the solder pot towards the substrate in a direction perpendicular to the x-y plane. The x-y-z mechanism 26 may include one or more motors, such as motor 27 illustrated in FIG. 3.

[0036] The slot soldering nozzle 28 generates a wave of molten solder across the relatively wide width of the nozzle preferably apply solder to the entire surface of the first substrate in one or more passes of the slot soldering nozzle across the surface. The slot soldering nozzle 28 is connected to a pump, such as pump 30 illustrated in FIG. 3. The pump 30 may be, for example, an impeller pump configured to move molten solder from the solder pot 22 through a solder channel, such as a tube, to the slot soldering nozzle 28, generating the wave of molten solder.

[0037] The solder pot 22 may be moved toward the substrate 20 via the x-y-z mechanism 26 such that the wave of molten solder generated by the slot soldering nozzle 28 comes into contact with the surface of the substrate 20. The slot soldering nozzle 28 is then moved by the x-y-z mechanism 26 to preferably solder the entire underside of the substrate 20. While the soldering machine 10 illustrated in the preferred embodiment of FIG. 3 comprises a single soldering pot, it is understood that the soldering machine 10 may comprise any number of solder pots. For example, the soldering machine 10 may comprise a first soldering pot in fluid communication with the slot soldering nozzle 28 and a second soldering pot in fluid

communication with the selective soldering nozzle 32.

[0038] As solder 24 is applied by the slot soldering nozzle 28, solder 24 adheres between the pins and holes of the components. The solder 24 that does adhere to the pins and holes remains in the solder wave and may flow back into the solder pot 22, to be reused by the soldering machine 10.

[0039] As mentioned above, the slot soldering nozzle 28 is preferably fixed in position with respect to the solder pot 22 and rides on top of the solder pot 22 as it is moved in the x-y-z directions.

[0040] The slot soldering nozzle 28 is an elongated slot soldering nozzle that has a much wider slot than the rectangular orifice nozzle shown in figure 4. In one embodiment, the slot soldering nozzle 28 may have a length of 200 mm (7.87 inches). However, it is understood that the slot soldering nozzle 28 may be of any length.

[0041] When used to solder a substrate 20 that is twice as wide as the slot soldering nozzle 28, the slot soldering nozzle 28 would first apply a wave of molten solder 24 to the left half of the substrate 20, for example, and then apply a wave of molten solder 24 to the right half of the substrate 20.

[0042] The selective soldering nozzle 32, on the other hand, is used to apply molten solder 24 to selected component pins on a substrate. It is not used to solder the entire surface of the substrate.

[0043] The selective soldering nozzle 32 is connected to a pump, such as pump 34 illustrated in FIG. 3. The pump 34 may be, for example, an impeller pump configured to drive molten solder from the solder pot 22 through a solder channel (not shown) to the selective soldering nozzle 32. The pump 34 moves molten solder 24 from the solder pot 22 through a tube (not shown) to the selective soldering nozzle 32 such that the selective soldering nozzle 32 can produce a column or fountain of solder 24 that extends above the top edge of the nozzle. As discussed herein, the solder pot 22, which contains the selective soldering nozzle 32, is preferably moved with respect the substrate 20 via the x-y-z mechanism 26. [0044] The selective soldering nozzle 32 is preferably reciprocated towards and away from the substrate (in the z direction) independently of the solder pot 22 and the slot soldering nozzle 28. This can be done using air cylinder as described above. In use, the selective soldering nozzle 32 is moved toward the substrate 20 to place molten solder 24 of the solder fountain in contact with a component pin, or grouping of component pins, of the substrate 20. For example, the selective soldering nozzle may be configured to solder a single component pin exposed on a surface of the PCB. After soldering that component, the selective soldering nozzle 32 may be configured to move in any of the x-direction, y-direction or z-direction in order to apply solder to another component pin, or group of pins, exposed on the surface of the PCB 20. In one embodiment, the selective soldering nozzle 32 may be configured to retract by moving, for example, in the z-direction, before soldering each individual component. In another embodiment, the selective soldering nozzle 32 may be configured to move in pre-determined direction on the substrate 20 and to solder a plurality of electrical component pins without retracting.

[0045] The selective soldering nozzle 32 may have a circular, square or rectangular aperture, for example. In one embodiment, the soldering machine 10 may comprise a first selective soldering nozzle and a second selective soldering nozzle. The first selective soldering nozzle may have a circular aperture with a first diameter, for example, 10 mm, while the second selective soldering nozzle having a circular aperture with a second diameter, for example, 4 mm. FIGs. 4 and 5 illustrate a plurality of selective soldering nozzles 32, each having a different shape and size.

[0046] As further discussed herein, the soldering machine 10 may be configured to implement instructions contained in a soldering program for applying molten solder to the substrate 20. The soldering program may contain instructions for controlling any of the components of soldering machine 10.

[0047] In one embodiment, the soldering machine 10 may comprise a controller connected to a first pump, such as pump 30, configured to move molten solder from the solder pot 22 to the slot soldering nozzle 28, and to a second pump, such as pump 30, configured to move molten solder from the solder pot 22 to the selective soldering nozzle 32. In one embodiment, pump 30 and pump 34 may be, for example, impeller pumps or electromagnetic pumps. In one embodiment, the pump 30 may be a first type of pump and pump 34 may be a second type of pump. For example, the slot soldering nozzle 28 may be connected to an impeller pump 30 while the selective soldering nozzle 32 may be connected to an electromagnetic pump 34.

[0048] In another embodiment, the slot soldering nozzle 28 and the selective soldering nozzle 32 may be connected to a single pump. A controller may control a diverter to divert the molten solder between the slot soldering nozzle 28 and the selective soldering nozzle 32. The controller may control the diverter based on a predetermined soldering program with instructions to apply molten solder to the substrate using at least one of the slot soldering nozzle 28 or the selective soldering nozzle 32.

[0049] In the preferred embodiment, the top edge of slot soldering nozzle 28 is fixed in position above the top edge of selective soldering nozzle 32 when that nozzle is in its down (non- operative) position so that the selective soldering nozzle 32 does not come into contact with the substrate 20 while molten solder is applied to a surface of the substrate 20 using the slot soldering nozzle 28. In this preferred embodiment, the top edge of slot soldering nozzle 28 is fixed in position above the top edge of selective soldering nozzle 32 when that nozzle is in its down (non-operative) position, and the top edge selective soldering nozzle 32 is movable to an up position above the top edge of the slot soldering nozzle so that the selective soldering nozzle 32 can selectively apply solder to component pins without slot soldering nozzle 28 coming into contact with the substrate 20.

[0050] In one embodiment, to avoid contamination of the molten solder 24, the solder pot 22, an outlet area of the slot soldering nozzle 28 and the selective soldering nozzle 32 may be contained in a protective gas atmosphere. This protective gas atmosphere may have low levels of oxygen and higher levels of nitrogen than are present the surrounding atmosphere. This protective gas atmosphere may reduce the production of lead oxide or tin oxide (in the event that the molten solder comprises lead or tin, respectively) and may also reduce the surface tension on the leads so that the solder breaks away more easily.

[0051] When the soldering program for the substrate 20 is complete, the substrate 20 may be transported along the conveyor mechanism 12 to the inspection unit 36. The inspection unit 36 may be set up for automatic optical testing and is used for inspecting, for example, a quality of the individual solder joints. If the substrate 20 has is found to have any defects, the substrate 20 may be placed back into the soldering zone 19 for corrections to be made by the one or more soldering nozzles. Alternatively, the substrate may be taken to a repair station (not shown) in the soldering machine 10. After the substrate has passed inspection, the substrate 20 may be moved from the inspection unit to a cooling stage.

[0052] The soldering machine 10 may comprise a cooling component 38 to ensure, for example, that all soldered connections have solidified. The cooling stage may comprise, for example, a fan configured to blow cool air at a predetermined temperature on the substrate 20. From the cooling stage, the substrate 20 may be fed to a discharge point (not shown) by the conveyor mechanism 12 where the substrate 20 may be removed from the soldering machine 10.

[0053] The soldering machine 10 may comprise a barcode reader (not shown) of a system controller that is configured to read a barcode located on the substrate. The system controller in response to signals from the barcode reader will use one of the slot soldering nozzle 28 or the selective soldering nozzle 32 in accordance with a computer program. For example, upon entering the soldering zone 19, the barcode reader signals may indicate that the entire surface of the substrate is to be soldered, causing the system controller to supply solder to the slot soldering nozzle 28 and raise the solder pot 22 and wave of molten solder be generated from the slot soldering nozzle 28 to solder the entire surface of the substrate.

[0054] As shown in FIG. 2, the soldering machine 10 may comprise one or more monitors 42 for viewing the multiple components of the soldering machine 10. For example, the soldering machine 10 may comprise one or more cameras connected to the one or more monitors 42 which allow the user to view, from the one or more monitors 42, the progress of the one or more soldering nozzles as they apply molten solder to the substrate 20. In addition, a user interface, separate or part of the monitors 42, may allow a user of the soldering machine 10 to select one of the slot soldering nozzle 28 or the selective soldering nozzle 32 for applying molten solder to a first substrate or the second substrate. By interacting with the user interface, the user may override the pre-determined computer program or even create a personalized soldering process for a given substrate.

[0055] FIG. 6 illustrates a soldering machine 10 comprising a slot soldering nozzle 28 and two selective soldering nozzles 32a and 32b. The two selective soldering nozzles may comprise a first selective soldering nozzle 32a with an aperture having a first shape/size and a second selective soldering nozzle 32b with an aperture having a second shape/size. The soldering machine 10 may further comprise a first pump 34a configured to move molten solder from the solder pot 22 to the first selective soldering nozzle 32a, a second pump 34a configured to move molten solder from the solder pot 22 to the second selective soldering nozzle 32b, and a third pump 30 configured to move molten solder from the solder pot 22 to the slot soldering nozzle 28. The soldering machine 10 may be configured to apply molten solder to a substrate 20 using one of the slot soldering nozzle 28, the first selective soldering nozzle 32a or the second selective soldering nozzle 32b. For example, the soldering machine 10 may comprise a barcode reader configured to read a barcode on the substrate, and apply a soldering program associated with the barcode.

[0056] FIGS 7-10 illustrate the preferred embodiment of the soldering machine 10, as discussed herein. FIG. 7 illustrates a portion of a soldering machine 10 comprising a relatively wide slot soldering nozzle 28, a first selective soldering nozzle 32a and a second selective soldering nozzle 32b. FIGS. 8-10 illustrate various depictions of a portion of a soldering machine 10 comprising the soldering nozzle 28, a first selective soldering nozzle 32a and a second selective soldering nozzle 32b.

[0057] It is understood that the soldering process performed by soldering machine 10 may be started or stopped at any point in the soldering machine 10. For example, the substrate 20 may be placed directly into the soldering zone 19 without going through any of the fluxer 14, topside heating mechanism 16 or bottom side heating mechanism 18 components. In another example, the substrate 20 may be soldered at the soldering zone 19 but may be removed without passing through the cooling component 38 or the inspection unit 40.

[0058] It is further understood that more than one substrate 20 may be placed into the soldering machine 10 at a given time. For example, the conveyor mechanism 12 may be configured to receive a plurality of substrates and to feed the substrates into the machine one at a time. As such, a first substrate may be soldered using the slot soldering nozzle 28, while a subsequent substrate may be soldered using the first selective soldering nozzle 32a and/or the second selective soldering nozzle 32b

[0059] It is further understood that the ordering of the components of the soldering machine 10 shown in FIGS. 1-3 is not necessary and that the components may be placed in any order. The soldering machine 10 may have absolute control over all critical parameters, for example, the temperature of the molten solder, the height and travel speed of the solder wave, and the preheat soak time. [0060] It will be appreciated that the foregoing description provides examples of the disclosed machine. However, it is contemplated that other implementations of the invention may differ in detail from the foregoing examples. All references to the invention or examples thereof are intended to reference the particular example being discussed at that point and are not intended to imply any limitation as to the scope of the invention more generally. All language of distinction and disparagement with respect to certain features is intended to indicate a lack of preference for those features, but not to exclude such from the scope of the invention entirely unless otherwise indicated. All methods described herein can be performed in any suitable order unless otherwise indicated herein or otherwise clearly contradicted by context.

Claims

What is claimed is:

1. An apparatus for applying solder to a substrate, the apparatus comprising:

a slot soldering nozzle configured to apply a wave of molten solder across substantially the entire surface of a first substrate in one or more passes across the first substrate;

at least one selective soldering nozzle configured to selectively apply molten solder to selected component pins or groups of component pins on a second substrate; and

a solder pot for containing the molten solder, the solder pot being in fluid communication with both the slot soldering nozzle and the selective soldering nozzle.

2. An apparatus for applying solder to a substrate, the apparatus comprising:

a slot soldering nozzle configured to apply a wave of molten solder to a first substrate; at least one selective soldering nozzle configured to selectively apply molten solder to one or more selected component pins on a second substrate; and

a solder pot for containing the molten solder, the solder pot being in fluid communication with both the slot soldering nozzle and the selective soldering nozzle,

wherein the slot soldering nozzle moves in the x-y-z directions with the solder pot, and the selective soldering nozzle moves in the x-y directions with the solder pot and is

independently movable in the z direction with respect to the solder pot.

3. An apparatus for applying solder to a substrate, the apparatus comprising:

a slot soldering nozzle configured to apply a wave of molten solder to a first substrate; at least one selective soldering nozzle configured to selectively apply molten solder to selected component pins or groups of component pins on a second substrate; and

wherein the selective soldering nozzle is movable between an up position and a down position, and wherein the top edge of the slot soldering nozzle is located above the top edge of the selective soldering nozzle when the selective soldering nozzle is in the down position, and wherein the top edge of the selective soldering nozzle is above the top edge of the slot nozzle when the selective soldering nozzle is in the up position.

4. An apparatus for applying solder to a substrate, the apparatus comprising: a slot soldering nozzle configured to apply a wave of molten solder to a first substrate; at least one selective soldering nozzle configured to selectively apply molten solder to selected component pins or groups of component pins on a second substrate; and

wherein the slot soldering nozzle is movable with the solder pot between an up position and a down position, and wherein the top edge of the slot soldering nozzle is located below the top edge of the selective soldering nozzle when the slot soldering nozzle is in the down position, and wherein the top edge of the slot soldering nozzle is above the top edge of the selective nozzle when the slot soldering nozzle is in the up position.

5. The apparatus of any one of claims 1-4, further comprising a pump configured to move molten solder from the solder pot to at least one of the slot soldering nozzle and the selective soldering nozzle.

6. The apparatus of claim 5, wherein the pump comprises a first pump configured to move molten solder from the solder pot to the slot soldering nozzle and a second pump configured to move molten solder from the solder pot to the selective soldering nozzle, the second pump being different from the first pump.

7. The apparatus of claim 6, further comprising a controller configured to control operation of the first pump and the second pump.

8. The apparatus of claim 7, wherein the controller controls the operation of the first pump and the second pump based on a predetermined soldering program with instructions to apply molten solder to at least one of the first substrate or the second substrate using at least one of the slot soldering nozzle or the selective soldering nozzle.

9. The apparatus of any one of claims 1-4, wherein the second substrate is different from the first substrate.

10. The apparatus of any one of claims 1-4, wherein the slot soldering nozzle is configured to apply the wave of molten solder across a plurality of exposed components in the portion of the first substrate.

11. The apparatus of any one of claims 1-4, wherein the selective soldering nozzle is configured to apply molten solder to a subset of a plurality of exposed component pins on the second substrate.

12. The apparatus of any one of claims 1-4, further comprising a controller configured to control a diverter to divert the molten solder between the slot soldering nozzle and the selective soldering nozzle.

13. The apparatus of claim 12, wherein the controller controls the diverter based on a predetermined soldering program with instructions to apply molten solder to at least one of the first substrate or the second substrate using at least one of the slot soldering nozzle or the selective soldering nozzle.

14. The apparatus of claim 12, wherein the controller is connected to a first pump configured to move molten solder from the solder pot to the slot soldering nozzle and to a second pump configured to move molten solder from the solder pot to the selective soldering nozzle, the second pump being different from the first pump.

15. The apparatus of any one of claims 1-4, further comprising an interface, the interface configured to receive a selection of one of the slot soldering nozzle or the selective soldering nozzle for applying molten solder to the first substrate or the second substrate.

16. The apparatus of any one of claims 1 and 4, wherein the slot soldering nozzle moves in the x-y-z direction with the solder pot, and wherein the selective soldering nozzle moves in the x-y direction with the solder pot and is independently movable in the z direction with respect to the solder pot.

17. The apparatus of any one of claims 1-3, wherein the selective soldering nozzle is movable between an up position and a down position, and wherein the top edge of the slot soldering nozzle is located above the top edge of the selective soldering nozzle when the selective soldering nozzle is in the down position, and wherein the top edge of the selective soldering is above the top edge of the slot nozzle when the selective soldering nozzle is in the up position.

18. The apparatus of any one of claims 1-4, wherein the solder pot is in fluid

communication with one slot soldering nozzle and two selective soldering nozzles.

19. The apparatus of claim 18, wherein the two selective soldering nozzles comprise a first selective soldering nozzle with an aperture having a first diameter and a second selective soldering nozzle with an aperture having a second diameter, the second diameter being different from the first diameter.

20. The apparatus of claim 19, further comprising a first pump configured to move molten solder from the solder pot to the first selective soldering nozzle, a second pump configured to move molten solder from the solder pot to the second selective soldering nozzle, and a third pump configured to move molten solder from the solder pot to the slot soldering nozzle, the first pump, the second pump, and the third pump being different.

21. The apparatus of claim 20, wherein the wave of molten solder is generated by pumping the molten solder from the solder pot through a tip of the slot soldering nozzle using the third pump.

22. The apparatus of claim 20, wherein the solder pot is configured to be moved in a direction toward the first substrate such that the wave of molten solder contacts the portion of the first substrate.

23. The apparatus of claim 22, wherein the wave of molten solder is moved across the bottom surface of the substrate.

24. The apparatus of any one of claims 1-4, wherein at least one of the first substrate or the second substrate is moved relative to the solder pot.

25. The apparatus of claim 24, wherein at least one of the first substrate or the second substrate is moved over the solder pot.

26. The apparatus of any one of claims 1-4, wherein the solder pot is moved relative to at least one of the first substrate or the second substrate.

27. The apparatus of claim 26, wherein the solder pot is moved under at least one of the first substrate or the second substrate.

28. The apparatus of any one of claims 1-4, wherein the selective soldering nozzle is moved relative to the solder pot.

29. The apparatus of claim 28, wherein the selective soldering nozzle is moved away from the solder pot in a direction toward the second substrate.

30. The apparatus of any one of claims 1-4, further comprising an x-y-z mechanism configured to move the solder pot.

31. The apparatus of any one of claims 1-4, further comprising a barcode reader configured to read a barcode located on at least one of the first substrate or the second substrate.

32. The apparatus of claim 31, wherein the barcode encodes a soldering program to use one of the slot soldering nozzle or the selective soldering nozzle.

33. A method for applying solder to a substrate, the method comprising:

moving molten solder from a solder pot containing the molten solder to at least one slot soldering nozzle at a first time;

applying a wave of molten solder across substantially the entire surface of a first substrate in one or more passes across the first substrate using the slot soldering nozzle;

moving molten solder from the solder pot to at least one selective soldering nozzle at a second time; and

selectively applying molten solder to selected component pins or groups of component pins on a second substrate using the selective soldering nozzle.

34. The method of claim 33, wherein:

moving the molten solder from the solder pot to the slot soldering nozzle comprises pumping the molten solder from the solder pot to the slot soldering nozzle; and

moving the molten solder from the solder pot to the selective soldering nozzle comprises pumping the molten solder from the solder pot to the selective soldering nozzle.

35. The method of claim 34, wherein:

moving the molten solder from the solder pot to the slot soldering nozzle comprises pumping the molten solder from the solder pot to the slot soldering nozzle using a first pump; and

moving the molten solder from the solder pot to the selective soldering nozzle comprises pumping the molten solder from the solder pot to the selective soldering nozzle using a second pump that is different from the first pump.

36. The method of claim 33, wherein the second substrate is different from the first substrate.

37. The method of claim 33, wherein applying the wave of molten solder across substantially the entire surface of the first substrate in one or more passes across the first substrate using the slot soldering nozzle comprises applying the wave of molten solder to substantially all of the component pins on the entire surface of the first substrate in one or more passes across the first substrate using the slot soldering nozzle.

38. The method of claim 33, further comprising diverting the molten solder between the slot soldering nozzle and the selective soldering nozzle between the first time and the second time.

39. The method of claim 33, wherein diverting the molten solder between the slot soldering nozzle and the selective soldering nozzle comprises receiving a predetermined soldering program with instructions to apply molten solder using one of the slot soldering nozzle and the selective soldering nozzle.

40. The method of claim 33, further comprising receiving, through an interface, one of the slot soldering nozzle or the selective soldering nozzle for applying molten solder to the first substrate or the second substrate.

41. The method of claim 33, wherein applying the wave of molten solder across substantially the entire surface of the first substrate in one or more passes across the first substrate using the slot soldering nozzle comprises moving the solder pot and slot soldering nozzle together in at least one of the x-direction, y-direction or z-direction.

42. The method of claim 33, wherein selectively applying molten solder to the selected component pins or groups of component pins on the second substrate using the selective soldering nozzle comprises moving the solder pot and selective soldering nozzle together in the x-y direction, and independently moving the selective soldering nozzle in the z direction with respect to the solder pot.

43. The method of claim 42, wherein selectively applying molten solder to the selected component pins or groups of component pins on the second substrate using the selective soldering nozzle comprises moving the top edge of the selective soldering nozzle to be above the top edge of the slot nozzle.

44. The method of claim 33, wherein selectively applying molten solder to the selected component pins or groups of component pins on the second substrate using the selective soldering nozzle comprises moving the top edge of the selective soldering nozzle to be above the top edge of the slot nozzle.

45. The method of claim 33, wherein:

moving molten solder from the solder pot to at least one slot soldering nozzle comprises moving molten solder from the solder pot to a single soldering nozzle; and

moving molten solder from the solder pot to at least one selective soldering nozzle comprises moving molten solder from the solder pot to one of a first selective soldering nozzle and a second selective soldering nozzle, the second selective soldering nozzle being different from the first selective soldering nozzle.

46. The method of claim 45, wherein:

moving molten solder from the solder pot to a first selective soldering nozzle comprises moving molten solder from the solder pot to a first selective soldering nozzle with an aperture having a first diameter; and

moving molten solder from the solder pot to a second selective soldering nozzle comprises moving molten solder from the solder pot to a second selective soldering nozzle with an aperture having a second diameter, the second diameter being different from the first diameter.

47. The method of claim 45, wherein:

moving the molten solder from the solder pot to the first selective soldering nozzle comprises pumping the molten solder from the solder pot to the first selective soldering nozzle using a first pump;

moving the molten solder from the solder pot to the second selective soldering nozzle comprises pumping the molten solder from the solder pot to the second selective soldering nozzle using a second pump; and moving the molten solder from the solder pot to the slot soldering nozzle comprises pumping the molten solder from the solder pot to the slot soldering nozzle using a third pump, the first pump, the second pump, and the third pump being different pumps.

48. The method of claim 47, wherein the wave of molten solder is generated by pumping the molten solder from the solder pot through a tip of the slot soldering nozzle using the third pump.

49. The method of claim 48, wherein applying the wave of molten solder across substantially the entire surface of the first substrate in one or more passes across the first substrate using the slot soldering nozzle comprises moving the solder pot in a direction toward the first substrate such that the wave of molten solder contacts the bottom surface of the first substrate.

50. The method of claim 49, wherein applying the wave of molten solder across substantially the entire surface of the first substrate in one or more passes across the first substrate using the slot soldering nozzle comprises moving the first substrate across the wave of molten solder.

51. The method of claim 33, wherein:

applying the wave of molten solder across substantially the entire surface of the first substrate in one or more passes across the first substrate using the slot soldering nozzle comprises moving the first substrate relative to the solder pot, and

selectively applying molten solder to the selected component pins or groups of component pins on the second substrate using the selective soldering nozzle comprises moving the second substrate relative to the solder pot.

52. The method of claim 51, wherein:

applying the wave of molten solder across substantially the entire surface of the first substrate in one or more passes across the first substrate using the slot soldering nozzle comprises moving the first substrate over the solder pot, and selectively applying molten solder to the selected component pins or groups of component pins on the second substrate using the selective soldering nozzle comprises moving the second substrate over the solder pot.

53. The method of claim 52, applying the wave of molten solder across substantially the entire surface of the first substrate in one or more passes across the first substrate using the slot soldering nozzle comprises moving the solder pot under at least one of the first substrate.

54. The method of claim 33, selectively applying molten solder to the selected component pins or groups of component pins on the second substrate using the selective soldering nozzle comprises moving the selective soldering nozzle relative to the solder pot.

55. The method of claim 54, selectively applying molten solder to the selected component pins or groups of component pins on the second substrate using the selective soldering nozzle comprises moving the selective soldering nozzle away from the solder pot in a direction toward the second substrate.

56. The method of claim 33, applying the wave of molten solder across substantially the entire surface of the first substrate in one or more passes across the first substrate using the slot soldering nozzle comprises lifting the solder pot using a lift mechanism.

57. The method of claim 33, further comprising reading a barcode located on at least one of the first substrate or the second substrate.

58. The method of claim 57, further comprising determining whether to use the slot soldering nozzle or the selective soldering nozzle based information encoded in the barcode.