DE202021105328U1 - Generation of a solder ring and assembly of a workpiece with the solder ring - Google Patents

Abstract

System (10) for producing ring-shaped preformed solder parts (13) from solder wire (11) and for the automated assembly of an assembly of a workpiece (12) to be soldered with an annular preformed solder part (13) produced,
characterized,
that a cutting-bending station (14) is available, which is set up to cut a preform for the later solder preform (13) by means of a cutting device (14a) from an endless solder wire (11 ') in a predetermined length and then by means of forming a bending device (14b) into a ring;
that there is a conveyor device (15) for transporting the workpiece (12) to be fitted into a fitting position in the region of the cutting-bending station (14);
that a detector device (16) for determining the exact current spatial position of the workpiece (12) after its transport into the area of the cutting-bending station (14) and for detecting the exact current position and spatial orientation of a workpiece to be fitted ( 12) there are protruding receptacle pins (12a);
that an automatable gripping system (17) for gripping the annular preformed solder part (13) produced in the cutting-bending station (14) and for moving it into an installation position on the receiving pin (12a) of the workpiece (12) to be fitted Placement position is available;
and that an electronic control device (18) for controlling or regulating the movement of the gripping system (17) based on electronic information from the detector device (16) about the current position and spatial orientation of the workpiece ( 12) protruding mounting pins (12a) are present.

Description

The invention relates to a system for producing ring-shaped preformed solder parts from solder wire and for the automated assembly of a component to be soldered, in particular an electronic assembly of a workpiece, with a pre-formed annular preformed solder part.

Annular solder preforms of this type made from solder wire are known per se, for example from U.S. 3,239,125 A (= Reference [1]) or off DE 10 2014 118 521 A1 (= Reference [2]) or off CN 105127618 A (= Reference [3]).

Background of the invention

Various types of solder wire (or “solder wires” for soldering) and options for their processing are described, for example, on the website of Felder GmbH Löttechnik in D-46047 Oberhausen (see references [4a] and [4b]).

A special feed device for the linear feed of a wire along an axial direction by means of a conveying device for the purpose of processing solder wires is, for example, in DE 10 2005 058 308 B4 or EP 1 795 292 B1 (see reference [5]). This known wire feed device also has a control or regulating unit which emits a control signal to the conveying device which influences, in particular regulates, the linear displacement of the wire caused by the conveying device. A sensor unit, which comprises an electromechanical sensor which is rigidly connected to the feed device, generates an electronic measurement signal as a function of the measured pressure reaction force. This is forwarded as an input signal to the control or regulation unit.

The manufacture of ring-shaped solder preforms from solder wire is not addressed in reference [5].

The production of an annular preformed solder part from commercially available solder wires is known per se, as mentioned above. The solder wires can be filled with single-core or multi-core flux ("tube solder"). Solid wires without a flux core can also be processed (see below). As a rule, the ring-shaped solder preforms are produced with open ends. The gap between the two ends does not necessarily have to be completely closed. Instead of a material connection, a form connection is usually sufficient.

Preformed solder parts are used in assembly and connection technology (= AVT) and are used for the mechanical and electrical connection of solderable connection partners, in particular metals, but also ceramics, glass, etc.

Solder preforms usually have a precisely defined shape and thus ensure high reproducibility of the soldering point to be soldered.

• Bei THT wird im Lötvorgang nicht die gesamte Platine des zu bearbeitenden Werkstücks erhitzt, sondern lediglich ein spezifischer räumlicher Bereich. Damit ist eine Durchkontaktierung auch bei relativen hohen Liquidus-Temperaturen T_L ≥ 190°C oder sogar T_L ≥ 234°C des verwendeten Lot-Materials möglich.

When processing the solder joint, a distinction is made between two alternative methods, the so-called through-hole technology (= THT) and the technology of the so-called surface-mounted devices (= SMD):

• With THT, not the entire board of the workpiece to be processed is heated during the soldering process, but only a specific spatial area. This enables through-hole plating even at relatively high liquidus temperatures T _L 190 ° C. or even T _L 234 ° C. of the solder material used.

With the SMD method, contacting can only be carried out at significantly lower liquidus temperatures T _L ≥ 140 ° C. with the appropriate solder material, because the entire circuit board surface is heated here. Particularly sensitive electronic components must therefore be protected from possible overheating.

The selection of the process temperature depends on the solder used and the component to be soldered. SRS is a process for the selective soldering of wired components. Advantage of SRS soldering: Due to the local heating, surrounding components are not thermally stressed and the actual process temperature can be significantly higher than, for example, in a reflow process such as through-hole reflow (= THR). In this way, solders can be processed locally that deviate significantly upwards and downwards from the melting point of commercially available SAC solder.

Solder preforms with flux cores can be heated and melted together with the parts to be soldered directly, i.e. without the addition of external flux. One advantage of using solder wires with a flux core is that the flux exits uniformly, which has the task of reducing the surface oxides present on the components to be soldered and thus re-creating a metallically wettable surface. The flux also supports the flow behavior of the solder and its wettability.

On the other hand, preformed solder parts made from solid wire must also be processed with a flux to be applied in order to achieve a corresponding reduction in the metallic surfaces. The advantage of this combination of solid wire / external Flux lies in the possibility of a free choice of the external flux. This can be optimally selected and coordinated with regard to the connection partner to be soldered. However, it is disadvantageous that an additional process step is required for these applications.

Object of the invention

The object of the present invention, on the other hand, is to improve a generic system of the type described at the beginning with the simplest possible and generally available technical means as well as economically inexpensive in such a way that the production of high-quality, constant soldering points is made possible, which is not carried out either by humans or by machines their design are impaired and have a very high reproducibility.

Brief description of the invention

According to the invention, this task, which is very demanding when viewed precisely, is achieved in a surprisingly simple and effective manner in that there is a cutting-bending station which is set up to produce a preform for the later solder preform by means of a cutting device from an endless Cut the solder wire to a predetermined length and then shape it into a ring by means of a bending device; that there is a conveyor device for transporting the workpiece to be fitted into a fitting position in the region of the cutting-bending station;
that there is a detector device for determining the exact current spatial position of the workpiece after its transport into the area of the cutting-bending station and for detecting the exact current position and spatial alignment of a receiving pin protruding from the workpiece to be equipped; that there is an automatable gripping system for gripping the ring-shaped solder preform produced in the cutting-bending station and for moving it into an installation position on the receiving pin of the workpiece to be fitted in the fitting position; and that there is an electronic control device for controlling or regulating the movement of the gripping system on the basis of electronic information from the detector device about the current position and spatial orientation of the receiving pin protruding from the workpiece to be fitted with the ring-shaped solder preform.

General mode of operation of the invention

The present invention enables a largely automated production, supply and placement of the preformed solder parts on the workpiece to be fitted.

From an endless roll of solder wire, a piece of wire of a predetermined length is fed sequentially into a specially designed cutting and bending station. In the cutting device, a piece of solder wire is cut to a predetermined length and then shaped into a ring by means of a bending device.

A suitable, automatable gripping system removes the ring-shaped solder preform from the solder ring shaping device and places it in the correct position at the soldering point of a workpiece, which is transported in parallel by a conveyor to its assembly position in the area of the cutting-bending station. There the solder ring is then placed over a receiving pin protruding away from the workpiece and can then be heated to create a soldering point.

The movement of the gripping system is automatically controlled or regulated by an electronic control device on the basis of information signals from a detector device with regard to the current position and spatial orientation of the receiving pin.

The approach proposed according to the invention thus pursues a fully automated production of soldering points on the workpiece, usually a circuit board equipped with electronic components.

Another aspect of the present invention is that products can (and should) be created that conform to an industrial standard. This achieves a high level of component accuracy and reproducibility, and components are created that are hermetically sealed. This is achieved through product qualification using standardized test procedures.

Preferred embodiments of the invention

Embodiments of the system according to the invention are particularly preferred which are characterized in that an arrangement for sequential linear wire feed from the endless solder wire by a predeterminable feed length is present at the cutting-bending station.

By exchanging the core and the bending segments, parameters such as core diameter and solder wire thickness can be adapted to the respective application.

In practice, very special developments of this class of embodiments, which are characterized in that the bending device is designed so that it can form a preformed solder part in the form of a circular ring or an oval ring or an angular, in particular rectangular ring from the molding coming from the cutting device.

The design of the shape to be generated can be implemented by appropriately shaping the core and bending segments. The mechanics are designed so that the shaping elements can be exchanged as a closed segment.

Embodiments of the system according to the invention are also particularly advantageous in which there is a pressing device for axially pressing the annular preformed solder part produced perpendicular to its annular plane.

This supports and enables assembly and processing / soldering of the solder rings on the assembly to be soldered in a very small space. With this option solder sleeves can be created. This has the effect that larger amounts of solder are deposited on a relatively small soldering pad and, with tight pin grids, do not interfere with each other and lead to solder bridges.

Embodiments of the invention which are characterized in that the detector device comprises an optical detector for determining the position of the workpiece and for detecting the position and spatial alignment of the receiving pin are also very particularly preferred.

This ensures that the ring is also stored in the position to be soldered so that it does not end up in a position in which it later produces a bad soldering and thus rejects. This is also important for the possible degree of automation of the process.

In further advantageous embodiments of the invention, the gripping system comprises a mechanical, electrical and / or pneumatic gripper. This can be rotated as desired / specifically from its ring receiving position to the ring deposit position in order to deposit the ring reliably and reproducibly with regard to packing / assembly density, and / or to be fed to the process point. This increases the ability to integrate into automated processes, both in high mix, low volume and in large-scale production.

Embodiments are also preferred in which the gripping system comprises at least one robot arm and / or at least one XYZ axis system.

A class of very particularly preferred embodiments of the invention is characterized in that a device for thermal action on the annular preformed solder part is present in its position on the receiving pin of the workpiece to be fitted, by means of which the annular preformed solder part on the exact by means of a heat source , specifically required temperature, usually a liquidus temperature T _L 140 ° C., in particular T _L 190 ° C., preferably T _L 234 ° C., can be heated.

With the use of special solder alloys, individual components can be soldered at low temperatures, from 140 ° C, but also soldered connections, for example components with connections made of enamelled copper wire, which require a process temperature of up to 500 ° C.

These embodiments can be further improved by further developments in which the device for thermal action on the annular preformed solder part has a heat source which can transfer heat to the preformed soldered part without contact, in particular a laser, preferably a diode laser, and / or an electrical induction -Device and / or a hot air device and / or an infrared device,
or in which the heat source can conduct heat to the annular preformed solder part through body contact, in particular by means of a soldering iron or soldering pliers. By separating the soldering ring positioning and / or soldering supply in a separate production step / process, from the heat input or the actual soldering process, the total process time required for the manufacture of assemblies is significantly reduced.

Alternatively or in addition, in advantageous developments of these embodiments, a device for spatial alignment of the heat source of the device for thermal action on the annular preformed solder part can be present, which, preferably based on signals from the electronic control device, can align the heat source in such a way that the preformed annular solder part in its position on the receiving pin of the workpiece to be assembled is optimally heated to a temperature to liquefy its solder wire components.

Another class of particularly preferred developments of these embodiments is characterized in that a test device is present, by means of which the quality of the soldering point can be checked, which was produced by the device for thermal action on the ring-shaped solder preform.

This enables an increase in the degree of automation and control loops for quality assurance.

In practice, variants of this class of developments in which the test device is set up to perform an optical and / or a mechanical and / or electrical test, in particular a resistance test, and / or an electronic test, in particular a functional test of the ring-shaped Solder preform equipped workpiece to perform on the quality of the solder joint produced.
This enables the integration of EOL systems (End of Line Tester).

1. (a) sequentieller linearer Drahtvorschub aus dem Endlos-Lotdraht um eine vorgebbare Vorschublänge in die Schneideinrichtung der Schneid-Biege-Station und Abschneiden eines Formlings für das spätere Lotformteil mittels der Schneideinrichtung in einer vorgegebenen Länge;
2. (b) Übergabe des Formlings an die Biegeeinrichtung und Formen eines offenen oder geschlossenen Rings aus dem Formling;
3. (c) Fördern eines zu bestückenden Werkstücks in eine Bestückungs-Position im Bereich der Schneid-Biege-Station mittels der Fördereinrichtung;
4. (d) Ermittlung der genauen aktuellen räumlichen Lage des zu bestückenden Werkstücks und Detektion der genauen aktuellen Position und räumlichen Ausrichtung eines aus dem zu bestückenden Werkstück ragenden Aufnahme-Pins mittels der Detektoreinrichtung;
5. (e) Ergreifen des in der Schneid-Biege-Station erzeugten ringförmigen Lotformteils und Bewegen in eine Einbau-Position am Aufnahme-Pin des zu bestückenden Werkstücks in der Bestückungs-Position mittels des Greifsystems;
6. (f) Steuerung oder Regelung der Bewegung des Greifsystems aufgrund von elektronischen Informationen aus der Detektoreinrichtung über die aktuellen Position und räumlichen Ausrichtung des aus dem mit dem ringförmigen Lotformteil zu bestückenden Werkstück ragenden Aufnahme-Pins mittels der elektronischen Steuerungseinrichtung.

A method for operating a system according to the invention for producing annular preformed solder parts from solder wire and for the automated assembly of an electronic assembly of a workpiece with a produced annular preformed solder part according to one of the preceding claims is also advantageous for the implementation of the invention, which is characterized by the following steps:

1. (A) sequential linear wire feed from the endless solder wire by a predeterminable feed length into the cutting device of the cutting-bending station and cutting off a molding for the later solder preform by means of the cutting device in a predetermined length;
2. (b) transferring the molding to the bending device and forming an open or closed ring from the molding;
3. (c) Conveying a workpiece to be fitted into a fitting position in the region of the cutting-bending station by means of the conveyor device;
4. (d) Determination of the exact current spatial position of the workpiece to be equipped and detection of the exact current position and spatial orientation of a receiving pin protruding from the workpiece to be equipped by means of the detector device;
5. (e) gripping the ring-shaped solder preform produced in the cutting-bending station and moving it into an installation position on the receiving pin of the workpiece to be fitted in the fitting position by means of the gripping system;
6. (f) Control or regulation of the movement of the gripping system on the basis of electronic information from the detector device about the current position and spatial orientation of the receiving pin protruding from the workpiece to be fitted with the ring-shaped solder preform by means of the electronic control device.

Variants of this method are particularly preferred, which are characterized in that the ring-shaped preformed solder part is brought to an exact specific temperature in its position on the receiving pin of the workpiece to be fitted by means of the heat source of the device for thermal action and is generated in a precisely assigned time window , in practice a liquidus temperature T _L ≥ 140 ° C, in particular T _L ≥ 190 ° C, preferably T _L ≥ 234 ° C.

A variant of the method is also advantageous in which the test device is used to check the quality of the soldering point that was produced by the device for thermal action on the annular preformed solder part.

Further advantages of the invention emerge from the description and the drawing. The features mentioned above and below can also be used according to the invention individually or collectively in any combination. The embodiments shown and described are not to be understood as an exhaustive list, but rather have an exemplary character for describing the invention.

Detailed description of the invention and drawing

In the schematic drawing, an embodiment of the invention is shown, which is explained in more detail in the following detailed description with reference to embodiments.

• 1 ein figuratives Aufbauschema einer Ausführungsform der erfindungsgemäßen Anlage; und
• 2 ein Flussdiagramm mit einer bevorzugten Variante des Verfahrens zum Betrieb einer erfindungsgemäßen Anlage.

Show it:

• 1 a figurative construction scheme of an embodiment of the system according to the invention; and
• 2 a flow chart with a preferred variant of the method for operating a system according to the invention.

In general, the invention is concerned with a further development in the field of soldering systems with regard to automation options. In particular, the invention describes a modified plant 10 for the production of ring-shaped solder preforms 13th made of solder wire 11th as well as for the automated assembly of an electronic assembly of a workpiece 12th , usually a circuit board or part of an electronic functional unit, with a ring-shaped solder preform produced 13th .

How out 1 easy to see, the present invention is characterized by the fact that
that a cutting-bending station 14th is available, which is set up to be a molding for the later solder preform 13th by means of a cutting device 14a from an endless solder wire 11 ' cut off in a predetermined length and then by means of a bending device 14b to shape into a ring;
that a conveyor 15th for transporting the workpiece to be assembled 12th into an assembly position in the area of the cutting-bending station 14th is available;
that a detector device 16 to determine the exact current spatial position of the workpiece 12th after its transport to the area of the cutting-bending station 14th and for the detection of the exact current position and spatial orientation of a workpiece to be fitted 12th protruding mounting pins 12a is available;
that an automatable gripping system 17th for gripping the in the cutting-bending station 14th generated annular solder preform 13th and to move into an installation position on the receiving pin 12a of the workpiece to be fitted 12th is present in the loading position;
and that an electronic control device 18th for controlling or regulating the movement of the gripping system 17th based on electronic information from the detector device 16 About the current position and spatial orientation of the from the with the ring-shaped solder preform 13th workpiece to be assembled 12th protruding mounting pins 12a is available.

According to the invention, the cutting-bending station 14th an arrangement for sequential linear wire feed from the endless solder wire 11 ' by a predeterminable feed length, the details of which are not specifically shown in the drawing.

Possibilities for designing preformed solder parts by means of the invention presented here do not only consist, as already described above, in the free selection of the mostly commercially available solder wires used, but also in their specific shape. In addition to the classic ring-shaped shape, pre-formed solder parts can also be used in a rectangular shape. For example, for soldering flat contacts. By reshaping the solder wire, it is possible to produce preformed solder parts in the shape of a sleeve. These are used when the components to be soldered are very close to one another or when a counter meniscus has to be created for soldering points in electronics production on through-hole printed circuit boards. For this purpose, with the help of the invention described here, the solder wire 11th by pressing before the bending process, shaped into an oval shape.

Usually the bending device 14b be designed so that it comes out of the from the cutting device 14a coming molding a solder preform 13th in the form of a circular ring or an oval ring or an angular, in particular rectangular ring. A pressing device (also not shown in greater detail in the drawing) for axially pressing the annular preformed solder part produced can also be used 13th be present perpendicular to its ring plane.

The detector device is also used in most applications 16 to determine the position of the workpiece 12th and for detecting the position and spatial alignment of the receiving pin 12a comprise an optical detector, as in FIG 1 indicated schematically. However, other types of position detection, such as mechanical or electronic devices, are also possible.

The gripping system can also 17th be designed in the most varied of ways according to the needs of the specific application and include, for example, a mechanical and / or electrical and / or pneumatic gripper. In addition, in the gripping system 17th a robot arm and / or an XYZ axis system can be used to automate the process, but these are not shown in detail in the drawing.

To match the one on the recording pin 12a applied solder ring 13th to effect a soldering, is in most embodiments of the system according to the invention 10 a device for thermal exposure 19th onto the ring-shaped solder preform 13th in its position on the receiving pin 12a of the workpiece to be fitted 12th to be available. The ring-shaped preformed solder part can then by means of a heat source 13th to the precise, specifically required temperature, generally a liquidus temperature T _L 140 ° C., in particular T _L 190 ° C., preferably T _L 234 ° C.

• - Berührende Verfahren, wie Lötkolben, Lötzangen oder Heizstempe
• - Berührungslose Verfahren, wie Laserquellen, Induktionsspulen, Konvektionswärme,
• - Infrarotstrahler und Heißluft.

The system according to the invention and the method described here are suitable for any form of heating:

• - Contact methods such as soldering iron, soldering pliers or heating stamps
• - Contactless processes such as laser sources, induction coils, convection heat,
• - Infrared heater and hot air.

The specific heat source is again only shown schematically in the drawing and can - depending on the special requirements in the specific application - in the most varied of ways be constructed: For example, heat can be applied to the ring-shaped solder preform in a contact-free manner 13th transmit, in particular a laser, preferably contain a diode laser, and / or an electrical induction device and / or a hot air device and / or an infrared device. It is also possible for the heat source to transfer heat to the annular preformed solder part through body contact 13th can conduct, especially through a soldering iron.

The thermal facility 19th can also use a device (again not shown in detail in the drawing) for spatial alignment of the heat source on the solder ring 13th have, which on the basis of signals from the electronic control device 18th the heat source can align such that the annular solder preform 13th in its position on the receiving pin 12a of the workpiece to be fitted 12th is optimally heated to a temperature to liquefy its solder wire components.

The automated feeding and placement of the preformed solder parts ensures that the preformed solder parts always have an identical orientation to the heat source. This is of particular importance for solder wires with a flux core. This enables the flux to exit the solder wire in a uniform and controllable manner, and the flux exiting can develop their reducing effect at the ideal point in time. This protects the oxide-free metallic surface from immediate re-oxidation. This is particularly important if the process does not take place in a protective gas atmosphere.

It is particularly advantageous if in embodiments of the system according to the invention 10 a test facility 20th is present as it is in 1 is indicated as an optical device. Using this test facility 20th the quality of the solder joint can be checked, which is determined by the device for thermal exposure 19th onto the ring-shaped solder preform 13th was generated. This test facility 20th can in turn be designed in a variety of ways specifically according to the specific requirements of the respective application: It can in particular be set up to carry out an optical and / or a mechanical and / or electrical test, in particular a resistance test, and / or an electronic test, in particular a functional test of the with the ring-shaped solder preform 13th equipped workpiece 12th to perform on the quality of the solder joint produced.

Concrete possibilities for the technical implementation of the invention:

1. 1. Solder wire is passed through a ring sensor; this recognizes the end of the wire.
2. 2. Solder wire is clamped by two gripping elements, one of which executes a lifting movement and thus generates the wire feed. This is limited in length via a fine adjustment. If necessary, the gripping element can also reshape the solder wire into an oval shape. The second gripping element fixes the advanced solder wire when the first gripping element has reached its predefined target value. Then the first gripping element opens its clamp and moves into its starting position for the next conveying process.
3. 3. The conveyed piece of solder wire is sheared off by a die and represents the geometric development of the solder preform.
4. 4. In the continuation of its path, the forming punch bends the solder wire section around a bending core to form an isosceles U and holds it firmly in this position.
5. 5. Two bending jaws arranged at right angles to the forming die close the preformed solder part in its ring shape. In certain cases it may be necessary to idealize this ring shape. For this purpose, a further forming die is used, which is arranged exactly opposite the first forming die and re-stamps the ring shape when the two bending jaws arranged at right angles have retracted again.
6. 6. Then both forming punches retract into their basic position and the preformed solder can be removed using the gripping system.
7. 7. The main parts of the gripping system consist of two spring steel gripping plates into which a groove is made. These grooves then ensure the ideal horizontal alignment of the preformed solder parts in the gripping system. After the grooves have been made in the spring steel sheets, they are reshaped with an associated tool in such a way that they enclose the preformed solder part by more than 90% on its surface line. The resilient effect of the spring steel gripper plates ensure tolerance compensation during the setting movement when the preformed solder part is placed over a contour. The gripping system must be able to be opened to pick up and put down the preformed solder parts. This is done by a motor-driven eccentric that is placed between the gripper plates. The opening width of the gripper is determined by the angle of rotation of the eccentric.
8. 8. The position of the preformed solder and target contour is determined by means of camera systems and by calculating the deviations from the target value, with which the actual value is then brought into harmony.

A variant of the method for operating a system according to the invention is particularly preferred 10 for the production of ring-shaped solder preforms 13th made of solder wire 11th as well as for the automated assembly of an electronic assembly of a workpiece 12th with a generated solder ring 13th as shown schematically in the flowchart of 2 is shown.

1. (a) sequentieller linearer Drahtvorschub aus dem Endlos-Lotdraht 11' um eine vorgebbare Vorschublänge in die Schneideinrichtung 14a der Schneid-Biege-Station 14 und Abschneiden eines Formlings für das spätere Lotformteil 13 mittels der Schneideinrichtung 14a in einer vorgegebenen Länge;
2. (b) Übergabe des Formlings an die Biegeeinrichtung 14b und Formen eines offenen oder geschlossenen Rings aus dem Formling;
3. (c) Fördern eines zu bestückenden Werkstücks 12 in eine Bestückungs-Position im Bereich der Schneid-Biege-Station 14 mittels der Fördereinrichtung 15;
4. (d) Ermittlung der genauen aktuellen räumlichen Lage des zu bestückenden Werkstücks 12 und Detektion der genauen aktuellen Position und räumlichen Ausrichtung eines aus dem zu bestückenden Werkstück 12 ragenden Aufnahme-Pins 12a mittels der Detektoreinrichtung 16;
5. (e) Ergreifen des in der Schneid-Biege-Station 14 erzeugten ringförmigen Lotformteils 13 und Bewegen in eine Einbau-Position am Aufnahme-Pin 12a des zu bestückenden Werkstücks 12 in der Bestückungs-Position mittels des Greifsystems 17;
6. (f) Steuerung oder Regelung der Bewegung des Greifsystems 17 aufgrund von elektronischen Informationen aus der Detektoreinrichtung 16 über die aktuellen Position und räumlichen Ausrichtung des aus dem mit dem ringförmigen Lotformteil 13 zu bestückenden Werkstück 12 ragenden Aufnahme-Pins 12a mittels der elektronischen Steuerungseinrichtung 18;
7. (g) Erhitzen des ringförmigen Lotformteils 13 in seiner Position auf dem Aufnahme-Pin 12a des zu bestückenden Werkstücks 12 mittels der Wärmequelle der Einrichtung zur thermischen Einwirkung 19 auf die genaue, konkret erforderliche Temperatur, in der Regel eine Liquidus-Temperatur T_L ≥ 140°C, insbesondere T_L ≥ 190°C, vorzugsweise T_L ≥ 234°C;
8. (h) Überprüfen der Qualität der Lötstelle mittels der Testeinrichtung 20, welche durch die Einrichtung zur thermischen Einwirkung 19 auf das ringförmige Lotformteil 13 erzeugt wurde, mittels der Testeinrichtung 20.

This process variant is characterized by the following steps:

1. (a) sequential linear wire feed from the endless solder wire 11 ' by a predeterminable feed length into the cutting device 14a the cutting-bending station 14th and cutting off a preform for the later solder preform 13th by means of the cutting device 14a in a predetermined length;
2. (b) Transfer of the molding to the bending device 14b and forming an open or closed ring from the molding;
3. (c) Conveying a workpiece to be equipped 12th into an assembly position in the area of the cutting-bending station 14th by means of the conveyor 15th ;
4. (d) Determination of the exact current spatial position of the workpiece to be fitted 12th and detection of the exact current position and spatial orientation of a workpiece to be fitted 12th protruding mounting pins 12a by means of the detector device 16 ;
5. (e) Grasping the in the cutting-bending station 14th generated annular solder preform 13th and moving to an installation position on the receiving pin 12a of the workpiece to be fitted 12th in the loading position by means of the gripping system 17th ;
6. (f) Control or regulation of the movement of the gripping system 17th based on electronic information from the detector device 16 about the current position and spatial orientation of the from the with the ring-shaped solder preform 13th workpiece to be assembled 12th protruding mounting pins 12a by means of the electronic control device 18th ;
7. (g) heating the annular solder preform 13th in its position on the receiving pin 12a of the workpiece to be fitted 12th by means of the heat source of the device for thermal action 19th to the exact, specifically required temperature, generally a liquidus temperature T _L 140 ° C., in particular T _L 190 ° C., preferably T _L 234 ° C;
8. (h) Checking the quality of the solder joint by means of the test device 20th , which by the device for thermal exposure 19th onto the ring-shaped solder preform 13th was generated by means of the test device 20th .

1. 1. Optimiertes Lötergebnis, 100%ig in der Lot- und Flussmittelmenge reproduzierbares Lotergebnis
2. 2. Bis zu 50%ige Reduzierung von Produktions- bzw. Taktzeiten
3. 3. 50%ige Reduzierung von Produktionszeit, sodass nahezu 50% weniger Energiebedarf für die Produktion notwendig ist
4. 4. Kein Standby-Energiebedarf
5. 5. Signifikante Reduzierung von Ausschuss
6. 6. Bis zu 90%ige Reduzierung des Gesamt-Energiebedarfs gegenüber Verfahren mit vergleichbaren Ergebnissen in Durchsatz und Qualität
7. 7. Entfall von Stickstoff als Passivierungs- oder Aktivierungsgas im Prozess
8. 8. Entfall von komplexen Produktaufnahmen
9. 9. Halbierung der Prozessfläche
10. 10. Entfall aufwändiger Maskierungen zur Abschottung einer SMD Umgebung
11. 11. Reduzierung von Hitzestress für umliegende empfindliche Elektronikkomponenten des Werkstücks
12. 12. Integrationsfähigkeit in komplexe und bereits bestehende Fertigungsstraßen
13. 13. Einfache Anpassbarkeit an aktuelle Marktanforderungen: Das erfindungsgemäße System kann für hohe Stückzahlen ebenso genutzt werden, wie für Kleinstmengen mit hoher Varianz.
14. 14. Einsatzmöglichkeit verschiedenster Lotlegierungen innerhalb einer aktuellen technischen Aufgabe: Beispielsweise, wenn ein Bauteil mit niedrigschmelzendem Lot verlötet werden muss, das nur niedrigen Temperaturen ausgesetzt werden darf, andere Bauteile der zu bearbeitenden Baugruppe aber Standardlote benötigen.
15. 15. Nachhaltigkeit für Bestandstechnologie durch die einfache Nachrüstbarkeit der erfindungsgemäßen Technologie.

The great technical and also economic benefit of the invention consists in a large number of individual advantages:

1. 1. Optimized soldering result, 100% reproducible soldering result in the amount of solder and flux
2. 2. Up to 50% reduction in production and cycle times
3. 3. 50% reduction in production time, so that almost 50% less energy is required for production
4. 4. No standby energy requirement
5. 5. Significant reduction in scrap
6. 6. Up to 90% reduction in total energy consumption compared to processes with comparable results in terms of throughput and quality
7. 7. Elimination of nitrogen as a passivation or activation gas in the process
8. 8. Elimination of complex product images
9. 9. Halving the process area
10. 10. Elimination of complex masking to seal off an SMD environment
11. 11. Reduction of heat stress for the surrounding sensitive electronic components of the workpiece
12. 12. Ability to integrate into complex and already existing production lines
13. 13. Easy adaptability to current market requirements: the system according to the invention can be used for large numbers of items as well as for small quantities with high variance.
14. 14. Possible uses of various solder alloys within a current technical task: For example, if a component has to be soldered with low-melting solder that may only be exposed to low temperatures, but other components of the assembly to be processed require standard solders.
15. 15. Sustainability for existing technology due to the fact that the technology according to the invention can be easily retrofitted.

Reference list

• [1] US 3, 239,125 A
• [2] DE 10 2014 118 521 A1
• [3] CN 105127618 A
• [4a] http://www.lotdraht.de/
• [4b] https://www.felder.de/produkte/elektronikanwendungen/handloetenautomatenloeten/loetdraht.html
• [5] DE 10 2005 058 308 B4 ≈ EP 1 795 292 B1

Publications considered for the assessment of patentability:

• [1] US 3,239,125 A
• [2] DE 10 2014 118 521 A1
• [3] CN 105127618 A
• [4a] http://www.lotdraht.de/
• [4b] https://www.felder.de/produkte/elektronikan Zeiten/handloetenautomatloeten/loetdraht.html
• [5] DE 10 2005 058 308 B4 ≈ EP 1 795 292 B1

List of reference symbols

10

Plant for the production of ring-shaped solder preforms

11th

Solder wire

11 '

Endless solder wire

12th

workpiece

12a

Recording pin

13th

Solder preform

14th

Cutting-bending station

14a

Cutting device

14b

Bending device

15th

Conveyor device for transporting the workpiece to be loaded

16

Detector device for determining the spatial position of the workpiece

16 '

Detector device for determining the spatial position of the preformed solder part

17th

Gripping system for gripping the solder preform and moving it into an installation position

18th

electronic control device

19th

Device for thermal action on the preformed solder part in its position on the receiving pin of the workpiece to be fitted

20th

Test device to check the quality of the solder joint

(a)

sequential linear wire feed

(b)

Transfer of the molding to the bending device and forming a ring

(c)

Conveying a workpiece to be fitted into a fitting position

(d)

Determination of the spatial position of the workpiece to be equipped

(e)

Gripping the preformed solder part produced in the cutting and bending station and moving it into an installation position on the receiving pin

(f)

Control or regulation of the movement of the gripping system

(G)

Heating the solder preform in position on the receiving pin

(H)

Checking the quality of the solder joint

QUOTES INCLUDED IN THE DESCRIPTION

This list of the documents listed by the applicant was generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Patent literature cited

• US 3239125 A [0002]
• DE 102014118521 A1 [0002, 0061]
• CN 105127618 A [0002, 0061]
• DE 102005058308 B4 [0004, 0061]
• EP 1795292 B1 [0004, 0061]

Claims (12)

System (10) for producing ring-shaped preformed solder parts (13) from solder wire (11) and for the automated assembly of an assembly of a workpiece (12) to be soldered with a preformed ring-shaped solder part (13), characterized in that a cutting-bending station ( 14) is available, which is set up to cut a preform for the later solder preform (13) by means of a cutting device (14a) from an endless solder wire (11 ') in a predetermined length and then by means of a bending device (14b) to form a ring to shape; that there is a conveyor device (15) for transporting the workpiece (12) to be fitted into a fitting position in the region of the cutting-bending station (14); that a detector device (16) for determining the exact current spatial position of the workpiece (12) after its transport into the area of the cutting-bending station (14) and for detecting the exact current position and spatial orientation of a workpiece to be fitted ( 12) there are protruding receptacle pins (12a); that an automatable gripping system (17) for gripping the annular preformed solder part (13) produced in the cutting-bending station (14) and for moving it into an installation position on the receiving pin (12a) of the workpiece (12) to be fitted Placement position is available; and that an electronic control device (18) for controlling or regulating the movement of the gripping system (17) based on electronic information from the detector device (16) about the current position and spatial orientation of the workpiece ( 12) protruding mounting pins (12a) are present. Plant after Claim 1 , characterized in that an arrangement for sequential linear wire feed from the endless solder wire (11 ') by a predeterminable feed length is present at the cutting-bending station (14). Plant after Claim 1 or 2 , characterized in that the bending device (14b) is designed so that it can form a preformed solder part (13) in the form of a circular ring or an oval ring or an angular, in particular rectangular ring from the molding coming from the cutting device (14a). System according to one of the preceding claims, characterized in that there is a pressing device for axially pressing the annular preformed solder part (13) produced perpendicular to its annular plane. System according to one of the preceding claims, characterized in that the detector device (16) for determining the position of the workpiece (12) and for detecting the position and spatial alignment of the receiving pin (12a) comprises an optical detector. System according to one of the preceding claims, characterized in that the gripping system (17) comprises a mechanical, electrical and / or pneumatic gripper. System according to one of the preceding claims, characterized in that the gripping system (17) comprises at least one robot arm and / or at least one XYZ axis system. System according to one of the preceding claims, characterized in that there is a device for thermal action (19) on the annular preformed solder part (13) in its position on the receiving pin (12a) of the workpiece (12) to be equipped, through which means a heat source, the ring-shaped solder preform (13) can be heated to the exact, specifically required temperature, usually a liquidus temperature T _L ≥ 140 ° C, in particular T _L ≥ 190 ° C, preferably T _L ≥ 234 ° C. Plant after Claim 8 , characterized in that the device for the thermal action (19) on the annular preformed solder part (13) has a heat source which can transfer heat to the preformed soldered part (13) without contact, in particular a laser, preferably a diode laser, and / or an electrical induction device and / or a hot air device and / or an infrared device, or that the heat source can conduct heat to the ring-shaped solder preform (13) through body contact, in particular through a soldering iron. Plant according to one of the Claims 8 or 9 , characterized in that a device for the spatial alignment of the heat source of There is a device for thermal action (19) on the annular preformed solder part (13) which, preferably on the basis of signals from the electronic control device (18), can align the heat source in such a way that the preformed annular solder part (13) is in its position on the receiving Pin (12a) of the workpiece (12) to be fitted is optimally heated to a temperature for liquefying its solder wire components. Plant according to one of the Claims 8 until 10 , characterized in that a test device (20) is present, by means of which the quality of the soldering point can be checked, which was produced by the device for thermal action (19) on the annular preformed solder part (13). Plant after Claim 11 , characterized in that the test device (20) is set up to carry out an optical and / or a mechanical and / or electrical test, in particular a resistance test, and / or an electronic test, in particular a functional test of the preformed solder part (13) equipped with the ring Workpiece (12) to perform on the quality of the solder joint produced.

Images