Soldering nozzle and method for the production thereof

Abstract

A soldering nozzle (100) for selectively soldering assemblies by means of molten solder supplied through a soldering nozzle (100) from a solder bath. The soldering nozzle (100) is designed as a deep-drawn part. A method for the production of a soldering nozzle (100) is specified as well, including the provision of a blank (401); the drawing of the blank (401) through at least one female die (411, 421) by means of at least one male die (413, 422, 431) to produce an oblong shape (439) of locally annular or substantially annular cross-section, with a first end (436) corresponding to an action point of the male die (413, 422, 431) and a second end (437) corresponding to an introduction cross-section of the male die (413, 422, 431), the cross-section preferably increasing from the first end (436) towards the second end (437); and the formation of an opening (446) at the tip end (436).

Claims

1. A method for the selective soldering of an assembly, wherein molten solder is fed to the assembly through a soldering nozzle from a solder bath, wherein the soldering nozzle formed from a deep-drawn process.

2. The method according to claim 1, wherein the soldering nozzle has a first section of an approximately hollow-cylindrical shape of a first diameter, a second section of linearly increasing diameter adjoining the first section and a third section of an approximately hollow-cylindrical shape of a second diameter adjoining the second section, wherein the first section has at its end face a tip end with an outflow opening for molten solder and wherein the third section has at its end face a base end with an inflow opening for molten solder.

3. A method for the selective soldering of an assembly, comprising: forming a soldering nozzle formed from a deep-drawn process; providing molten solder in a solder bath; and feeding the molten solder to the assembly through the soldering nozzle.

4. The method according to claim 3, wherein forming the soldering nozzle includes providing the soldering nozzle with a finishing layer comprising a layer of Ni (nickel) and/or a layer of Au (gold), the nickel layer being a working layer, the gold layer being a lost layer.

5. The method according to claim 3, wherein forming the soldering nozzle includes drawing the soldering nozzle with a first section of an approximately hollow-cylindrical shape of a first diameter, a second section of linearly increasing diameter adjoining the first section and a third section of an approximately hollow-cylindrical shape of a second diameter adjoining the second section, wherein the first section has at its end face a tip end with an outflow opening for molten solder and wherein the third section has at its end face a base end with an inflow opening for molten solder.

6. The method according to claim 5, wherein the third section has a brim in the form of a disc-shaped cross-sectional widening at the base end, wherein the brim forms a level standing surface, wherein the brim merges with a curvature into the cylindrical part of the third section.

7. The method according to claim 3, wherein the soldering nozzle is produced from steel preferably having magnetic properties, the steel type used being 1.0330DC01 according to DIN EN 10130.

8. A soldering method comprising: providing a blank; drawing of the blank through at least one female die by means of at least one male die to produce an oblong shape of locally annular or substantially annular cross-section, with a first end corresponding to an action point of the male die and a second end corresponding to an introduction cross-section of the male die, the cross-section increasing from the first end towards the second end; forming an opening at the tip end; and selectively soldering assemblies with molten solder by supplying the molten solder from a solder bath through the opening to the assemblies.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0056] In the accompanying drawings, reference characters refer to the same parts throughout the different views. The drawings are not necessarily to scale; emphasis has instead been placed upon illustrating the principles of the invention. Of the drawings:

[0057] FIG. 1 is a diagrammatic representation of a soldering nozzle according to an embodiment of the present invention in longitudinal section;

[0058] FIGS. 2A to 2D are diagrammatic representations of a conventional soldering nozzle in a perspective full view, a view from below, a side view and a longitudinal section along a line D-D in FIG. 2C;

[0059] FIGS. 3A to 3D are diagrammatic representations of another conventional soldering nozzle in a perspective full view, a view from below, a side view and a longitudinal section along a line D-D in FIG. 3C; and

[0060] FIGS. 4A to 4F are diagrammatic representations of procedural steps of a method for the production of the soldering nozzle from FIG. 1 according to an embodiment of the invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0061] The invention now will be described more fully hereinafter with reference to the accompanying drawings, in which illustrative embodiments of the invention are shown. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art.

[0062] As used herein, the term “and/or” includes any and all combinations of one or more of the associated listed items. Further, the singular forms and the articles “a”, “an” and “the” are intended to include the plural forms as well, unless expressly stated otherwise. It will be further understood that the terms: includes, comprises, including and/or comprising, when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof. Further, it will be understood that when an element, including component or subsystem, is referred to and/or shown as being connected or coupled to another element, it can be directly connected or coupled to the other element or intervening elements may be present.

[0063] It will be understood that although terms such as “first” and “second” are used herein to describe various elements, these elements should not be limited by these terms. These terms are only used to distinguish one element from another element. Thus, an element discussed below could be termed a second element, and similarly, a second element may be termed a first element without departing from the teachings of the present invention.

[0064] Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.

[0065] The soldering nozzle 100 is designed as a deep-drawn part. The soldering nozzle 100 is an oblong, axisymmetric hollow body with two open end faces, a tip end 7 and a base end 8 and a substantially constant wall thickness T (FIG. 1). The soldering nozzle is designed to carry molten solder from the base end to the tip end, the base end being in particular designed for accommodation in the region of a solder bath of a soldering fixture (not shown in detail). The tip end 7 thus has an outflow opening for molten solder and the base end 8 has an inflow opening for molten solder. The soldering nozzle 100 tapers from the base end 8 towards the tip end 7. The outflow opening may in particular be narrower than the inflow opening. The soldering nozzle is thus in particular designed for use in a soldering fixture for the selective soldering of assemblies.

[0066] The soldering nozzle 100 can be produced from steel. The steel type used can be selected with regard to a good wettability for solder. The selected steel type can be magnetic, which offers advantages in handling and installation, since the soldering nozzle 100 can then be handled and held using magnetic devices. The steel 1.0330DC01 according to DIN EN 10130 (“DC01” in short) can be used for example. This has been found to be particularly suitable for parts that can be wetted by solder and is magnetic as well.

[0067] The surface quality of deep-drawn parts is typically very good and in particular smooth, which facilitates their use as flow passages for solder and can extend their service life considerably. The soldering nozzle 100 can in addition be provided with a finishing layer such as an Ni—Au alloy for example or a two-layer coating of Ni (nickel) on the one hand and Au (gold) on the other hand, so that the soldering nozzle is protected against the solder by the nickel component on the one hand and its wettability is improved by the gold component on the other hand and it can be stored without any problems.

[0068] The soldering nozzle 100 can have a first section 1 of an approximately hollow-cylindrical shape of an outer diameter D1 and an inner diameter D2, a second section 2 of linearly increasing diameter adjoining the first section 1 and a third section 3 of an approximately hollow-cylindrical shape of an inner diameter D3 adjoining the second section 2. The first section 1 can have the tip end 7. The third section 3 can have the base end 8. The third section 3 with the comparatively wide cross-section can serve as a solder reservoir region, and the first section 1 with the comparatively narrow cross-section can serve as a solder exit region facilitating a higher flow rate as well. The contour of the soldering nozzle 100 is on the whole adapted to the deep-drawing method.

[0069] The first section 1 can have a curvature 11 at the tip end 7 at its outer circumference. The curvature 11 facilitates the laminar flow-off of unused solder at the outer wall of the soldering nozzle 100 back into the solder bath. The curvature 11 can be a remnant from the deep-drawing process, as will be described in greater detail at a later point. The curvature 11 can be produced mechanically or reworked.

[0070] The third section 3 can have a brim 4 in the form of a disc-shaped cross-sectional widening at the base end 8. The brim 4 may form a level standing surface 41 which can be held by a holding device of a soldering fixture in a particularly simple way. The standing surface 41 can for example offer a large magnetic surface to a magnetic holding device in a soldering fixture and thus be held in a particularly stable position. The brim 4 also corresponds to a region in which the blank is still gripped by the blank holder of the deep-drawing tool at the end of the deep-drawing process and is therefore adapted to the deep-drawing method in a particularly advantageous way. The brim 4 can merge into the cylindrical part of the third section 3 with a curvature 41. This makes deep-drawing easier and facilitates a laminar inflow of the solder.

[0071] The dimensions of the soldering nozzle 100 can be adapted to the respective application. In a typical embodiment an overall length of the soldering nozzle 100 may be approximately 40 mm, a wall thickness T of the soldering nozzle 100 approximately 1.5 mm, an inner diameter D2 of the first section 1 at the tip end 7 (the outflow opening) approximately 4 mm (the outer diameter D1 thus being approximately 7 mm), the length of the first section 1 approximately 10 mm, an inner diameter D3 of the third section 3 at the base end 8 before the transition to the brim 4 approximately 10 mm, an outer diameter D4 at the outer circumference of the brim 4 approximately 25 mm and a curvature radius R4 at the transition from the cylindrical part of the third section 3 to the brim 4 approximately 2 mm. A curvature radius R4 may correspond to the wall thickness T and be approximately 1.5 mm in this embodiment. The optional finishing layer (not shown in the drawing) can have a first layer of approximately 3-5 μm nickel and a second layer of approximately 0.2 μm gold.

[0072] The inner diameter D3 of the third section 3 and the outer diameter D4 of the brim 4 can be adapted to an existing holding or reception fixture. For such an application these values can therefore be predetermined. The diameters D1, D2 of the first section 1 are more variable, however, although subjected to an upper limit by the inner diameter D3 of the third section 3, because it is impossible to produce a deep-drawn part which has a greater diameter towards the top than at the bottom in the region of the brim 4. If the soldering nozzle 100 requires a greater diameter at the first section 1, the inner diameter D3 at the section 2 has to be increased as well (e.g. to 20 mm), and a suitable holding fixture has to be provided at the soldering fixture.

[0073] A staggered system with nozzle holders for bottom diameters D3 in a predetermined stacking arrangement can be advantageous as well. This means that soldering nozzles 100 with a top diameter D2 of maximally a first stacking stage have the bottom diameter D3 of said stacking stage (e.g. 10 mm) and are pushed onto nozzle holders for said diameter, soldering nozzles 100 with a top diameter D2 above the first stacking stage and of maximally a second stacking stage have the bottom diameter D3 of the second stacking stage (e.g. 20 mm) and are pushed onto nozzle holders for said diameter, and so on.

[0074] In principle the bottom diameter D3 is greater than the top diameter D1 at the tip. The bottom diameter D3 can be adapted to a greater top diameter D1, i.e. for all nozzle geometries of a production series the bottom diameter D3 can correspond to the bottom diameter D3 designed for the maximum top diameter D1. This offers a greater variability in terms of the top diameter D1. The bottom diameter D3 can also be adapted to a large nozzle holder at a soldering machine. In such a case adapters can be provided which facilitate installation into smaller nozzle holders as well. This also facilitates the production of larger quantities of soldering nozzles of a standard size which can be used for different nozzle holders or machines.

[0075] The soldering nozzle 100 is designed for the selective soldering of assemblies by a molten solder supplied from a solder bath by the soldering nozzle.

[0076] A method for the production of the soldering nozzle 100 can essentially comprise the following steps: [0077] the provision of a blank 401 (FIGS. 4A, 4B); [0078] the drawing of the blank 401 through at least one female die 411, 412 to produce an oblong shape 439 of locally annular or substantially annular cross-section, with a first end 436 corresponding to an action point of the male die 413, 422, 431 and a second end 437 corresponding to an introduction cross-section of the male die 413, 422, 431, the cross-section preferably increasing from the first end 436 towards the second end 437 (FIGS. 4C-4R); and [0079] the formation of an opening 436 at the first end 436, which corresponds to the tip end 7 of the finished soldering nozzle 100.

[0080] The blank 401 can be provided in the form of a circular blank (FIG. 4A). The blank 401 can for example be produced by stamping from a strip or sheet metal and can have a thickness corresponding to a wall thickness T of the soldering nozzle 100 (FIG. 4B). In the present embodiment the wall thickness T can be 1.5 mm. Depending on the application, the wall thickness T can be more then 1.5 mm, for example approximately 2.25 mm or 3 mm, or less, for example approximately 1 mm or 0.5 mm. The blank 401 can be made of steel such as “DC01” or another, in particular magnetic, type. In some cases it can be advantageous if the steel has the property of wettability by solder, in particular of the soldering nozzle 100 is not coated with a wetting agent.

[0081] The blank 401 can be placed on a first female die 411 with a hole 415, so that the center of the blank 401 coincides with the axis of the hole 415, and pressed against the first female die 411 by a blank holder 412 (FIG. 4C). The hole 415 has a diameter which corresponds to the outer diameter of the eventual third section 3 of the soldering nozzle 100 (cf. FIG. 1). The hole 415 further has a curvature at its top circumference, the radius of which corresponds to the eventual rim radius R4 of the soldering nozzle 100 (cf. FIG. 1). A first male die 413 with an outer diameter corresponding to the inner diameter D3 of the eventual third section 3 of the soldering nozzle 100 approaches the hole 415 coaxial with its center in a feed direction 414 and draws the blank 401 to a length corresponding to a length of the eventual third section 3 of the soldering nozzle 100. To complete this procedural step, the first male die 413 pulls out in the opposite direction.

[0082] Following this, the first female die 411 can be placed with the blank 401 above a second female die 421 with an opening 424, so that an axis of the hole 415 coincides with that of the opening 424 (FIG. 4D). The opening 424 of the second female die 421 has a contour corresponding to an outer contour of the eventual second section 2 and an adjoining transition region in the eventual section 1 (cf. FIG. 1). A second male die 422 with an outer diameter corresponding to the inner diameter D3 of the eventual third section 3 of the soldering nozzle 100 and with a conical end with an outer contour corresponding to the inner contour of the eventual second section 2 of the soldering nozzle 100 then approaches in a feed direction 423 coaxial with a center of the hole 415 and the opening 525 and draws the blank 401 to a length and a contour corresponding to the length and contour of the eventual second section 2 of the soldering nozzle 100. To complete this procedural step, the second male die 422 pulls out in the opposite direction.

[0083] Following this, a third male die 431 can be inserted into the already formed cavity of the blank 401 up to the stop while maintaining (or changing as suitable) the positions of the blank 401, the first female die 411 and the second female die 421 (FIG. 4E). The third male die 431 is multi-part, with an outer die 432 and an inner die 433 axially movable in an axial bore of the outer die 432. The outer die 432 has an outer contour corresponding to the inner contour of the eventual third part 3 and the eventual second part 2 of the soldering nozzle 100 (cf. FIG. 1). The axial bore of the outer die 432 has a bore diameter corresponding to the inner diameter D2 of the eventual first section 1 of the soldering nozzle 100, as does an outer diameter of the inner die 433. The outer die is then pressed against the blank 401 in a holding direction 434 with a force F which is chosen such that the outer die 432 acts as an auxiliary blank holder against the second female die 421 when the inner die 433, guided by the axial bore of the outer die 432, approaches in a feed direction 435 and draws the blank 401 through the second female die 421 to a length and contour corresponding to a length and contour of the eventual first section 1 of the soldering nozzle 100. To conclude this procedural step, the inner die 433 reverses in the opposite direction and moves completely out of the blank 401 together with the outer die 432. It should be noted that the curvature radius R11 of the finished soldering nozzle 100 can already be formed at the first end 436 at the end of this procedural step by drawing to final length.

[0084] Following this, a fourth male die 441 can be inserted into the already formed cavity of the blank 401 up to the stop while maintaining (or changing as suitable) the positions of the blank 401, the first female die 411 and the second female die 421 (FIG. 4F). The fourth male die 441 corresponds to the second male die 422 in its shape while having a shorter conical end. The fourth male die 441 is then pressed against the blank 401 in a holding direction 422 in order to fix it relative to the second female die 421. A stamping mandrel 443 with an outer diameter corresponding to the inner diameter of the first section 1 of the soldering nozzle 100 then approaches from the outside in a feed direction 444 coaxial with the axial direction of the fourth male die 441 against the holding direction 442 thereof, in order to form an opening 446 in the first end 436 of the blank, which end now corresponds to a tip end 7 of the soldering nozzle 100. A stamping residue 445 is pushed through the first section 1 into a cavity of the second section 2, where it remains loosely and can fall out of the of the drawing tool when the soldering nozzle 100 is removed from the drawing tool. To conclude this procedural step, the stamping mandrel 443 and the fourth male die 441 reverse in the opposite direction and move out of the now finish-drawn soldering nozzle 100.

[0085] The soldering nozzle 100 is now removed from the tool and can be turned upside down to remove the stamping residue 445.

[0086] The opening 446 can optionally be reworked in terms of its shape, dimensions and/or surface quality.

[0087] The edge of the blank 401, which remains in the drawing process between the first female die 411 and the blank holder 412 and now forms the brim 4 of the soldering nozzle 100, can optionally be reworked to shape (calibrated).

[0088] After its removal the soldering nozzle 100 can in addition to be nickel- and/or gold-plated to form the finishing layer described above. Those skilled in the art are familiar with many variants of these procedural steps, which therefore do not have to be described here. The action time of the respective baths will be dimensioned by those skilled in the art in such a way that the desired coating thickness is obtained.

[0089] The method described above can be modified depending on the shape of the soldering nozzle 100 and in procedural respect.

[0090] The strokes of the male dies 413, 423 and 431 can be limited by depth stops, for example. Such depth stops can be provided at the die lining or as a seating surface for the drawn end of the blank 401.

[0091] The female dies may also be designed such that the blank is supported and guided from the outside during the entire drawing process.

[0092] When stamping out the opening 446 (FIG. 4F), the first section 1 can be enclosed by an annular sleeve (not shown) to avoid bulging or bending out of shape.

[0093] Multiple variations and supplements are conceivable for stamping out the opening 446 (FIG. 4F). Instead of the fourth male die 411, the second male die 422 or the third male die 431 can be used as an alternative, for example, if the stamping residue 455 is pushed still further into the cavity of the second section 2 with the aid of the stamping mandrel 443 after removing the second male die 422 or the third male die 431. If the third male die 431 is used for stamping out the opening 446 (FIG. 4F), the stamping residue 455 can also be pushed out with the aid of the inner die 433 or pushed into the axial bore of the outer die 432 with the aid of the stamping mandrel 443 after removing the stamping mandrel 443, or it can be removed from the soldering nozzle 100 together with the third male die 431 and then pushed out with the aid of the inner die 433. In a further variation the third male die 431 can be used in place of the stamping mandrel 443, which acts from the outside, to stamp out the opening 446 from the inside. For this purpose the inner die 433 can be designed as a stamping mandrel, or the inner die 433 can be replaced by a separate stamping mandrel after the blank 401 has been drawn to final length, and the opening 446 can be stamped out in an outward direction. In this process it would be advantageous to place a third female die (not shown) having a hole with a hole diameter corresponding to the outer diameter of the stamping mandrel below the first end 436 of the blank 401 (FIG. 4E).

[0094] Apart from the above, further methods for forming the opening 446 are conceivable as well, such as drilling or the removal of a part of the first end, perhaps by cutting, milling, shearing off or the like. When removing a part of the first end 446, the curvature radius R11 (cf. FIG. 1) would then have to be formed afterwards.

[0095] It should be noted that, as a result of the continuous drawing of the blank, an edge of the blank finally remains between the female die 411 and the blank holder 412; this edge then forms the brim 4 of the soldering nozzle 100 in the form of an approximately disc-shaped widening. If required, the brim 4 can optionally be machined to shape or dimension (calibrated) by stamping or cutting or edging.

[0096] Apart from this, the method illustrated and described here is only an example for carrying out the claimed method, its application being in no sense limited to the individual steps and measured described here. Depending on the shape of the soldering nozzle 100, it is conceivable to use only a single male die for drawing the blank 401 to shape and length in a single drawing step. Even the soldering nozzle 100 described here, with its specific shape, could if necessary be produced using a single male die reproducing the inner contour of the soldering nozzle 100. It is possibly advantageous to draw initially the first section 1, then the second section 2 and then the third section 3 with the brim 4, using several female dies consecutively. A plurality of male and female dies can be used in a plurality of individual steps in order to draw the soldering nozzle in sections to the various diameters.

[0097] In some variations the sequence of the drawing steps can be reversed, i.e. it is possible to form the tip with the narrowest diameter first and then widen the diameter of the adjoining sections progressively. In such variations the male die with the largest diameter can therefore be used last.

[0098] A multi-stage deep-drawing tool or a progressive compound tool can be used in the method. Such tools can work in linear or rotational sequence.

[0099] The fundamental ideal of the method is obviously based on the deep-drawing of the soldering nozzle. The procedural steps and tool forms described above are purely exemplary. The soldering nozzle according to the invention is described and illustrated purely by way of example. Details can be varied in a suitable way as required by those skilled in the art. The invention is in particular defined by the appended claims only and is not restricted by embodiment details described above. Individually described or illustrated features can be added or omitted individually or in combination with further described or illustrated features or subject matters thereof or another embodiment in order to form independent subject matters of the invention.

LIST OF REFERENCE NUMBERS

[0100] 100 Soldering nozzle [0101] 1 First section [0102] 2 Second section [0103] 3 Third section [0104] 4 Brim [0105] 7 Tip end [0106] 8 Base end [0107] 11 Curvature [0108] 41 Standing surface [0109] D1 Outer diameter 1st section [0110] D2 Inner diameter 1st section [0111] D3 Inner diameter 3rd section [0112] D4 Outer diameter brim [0113] L Nozzle length [0114] L1 Length of first section [0115] R4 Brim radius [0116] R11 Curvature radius [0117] T Wall thickness [0118] 200 Soldering nozzle (prior art) [0119] 201 Cylindrical section [0120] 202 First conical section [0121] 203 Second conical section [0122] 204 Shoulder [0123] 205 Holding notch [0124] 206 Flattening [0125] 207 First bore [0126] 208 Second bore [0127] 211 Curvature [0128] A208 Bore base angle [0129] D201 Cylinder diameter [0130] D204 Base diameter [0131] D207 First bore diameter [0132] D208 Second bore diameter [0133] L201 Length of cylindrical section [0134] L202 Length of 1st conical section [0135] L203 Length of 2nd conical section [0136] L208 Bore length [0137] R201 Curvature radius [0138] R205 Notch radius [0139] X206 Axial distance of flattening [0140] 300 Soldering nozzle (prior art) [0141] 301 Cylindrical section [0142] 302 Conical section [0143] 304 Base surface [0144] 307 First bore [0145] 308 Second bore [0146] 311 Curvature [0147] A302 Cone angle [0148] A308 Bore base angle [0149] D301 Cylinder diameter [0150] D304 Base diameter [0151] D307 First bore diameter [0152] D308 Second bore diameter [0153] L301 Length of cylindrical section [0154] L302 Length of conical section [0155] L308 Bore length [0156] R301 Curvature radius [0157] 401 Blank [0158] 411 First female die [0159] 412 Blank holder [0160] 413 First male die [0161] 414 Feed direction [0162] 415 Hole [0163] 421 Second female die [0164] 422 Second male die [0165] 423 Feed direction [0166] 424 Opening [0167] 425 End [0168] 431 Third male die [0169] 432 Outer die [0170] 433 Inner die [0171] 434 Holding direction [0172] 435 Feed direction [0173] 436 First end [0174] 437 Second end [0175] 439 Oblong shape [0176] 441 Fourth male die [0177] 442 Holding direction [0178] 443 Stamping mandrel [0179] 444 Feed direction [0180] 445 Stamping residue [0181] 446 Opening

[0182] While this invention has been particularly shown and described with references to preferred embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the scope of the invention encompassed by the appended claims.