WO2008022632A1

WO2008022632A1 - Electrical component, particularly measuring resistor, and method for the production of such an electrical component

Info

Publication number: WO2008022632A1
Application number: PCT/DE2007/001481
Authority: WO
Inventors: Gerhard Berghoff; Carsten Senche; Maximilian Steinmann; Ralf Gürtner; Volker Högendörfer; Detlef Neusatz; Zoltan Veres; Stefan Kimpfler
Original assignee: Conti Temic Microelectronic Gmbh
Priority date: 2006-08-24
Filing date: 2007-08-22
Publication date: 2008-02-28
Also published as: DE112007002548A5; DE102006039722A1

Abstract

The invention relates to an electrical component (1), particularly a measuring resistor, comprising at least one resistor element (R1 to R3) and several terminal elements (4.1 to 4.7). The resistor element (R1 to R3) and the terminal elements (4.1 to 4.7) are formed from a flat strip (2) of a metal alloy. Said flat strip (2) is provided with an essentially tunnel-shaped central section (2.3) and ends (2.1, 2.2) which are bent at a right angle in the longitudinal direction at the end. At least one of the bent ends (2.1, 2.2) is fitted with at least one slot (3, 3.1, to 3.2), at least part of which extends along the longitudinal direction of the flat strip (2), perpendicular to the bent end (2.1, 2.2).

Description

Electrical component, in particular measuring resistor and method for producing such an electrical component

The invention relates to an electrical resistance, in particular measuring resistor and method for producing such an electrical component.

The electrical resistance is, in particular, a surface-mounted measuring resistor which is applied in so-called SMD (surface-mounted device) design by means of, for example, connection contacts to contact surfaces, such as conductor tracks of a printed circuit board. The connection contacts with the contact surfaces of the circuit board z. B. by electron beam welding or soldering together.

EP 0 605 800 B1 discloses such a surface-mountable resistor in which an electrically and mechanically connecting resistance element is arranged between two separate connection parts, the two connection parts and the resistance element being plate-shaped and connecting the two connection parts to the edges of the plate-shaped one

Resistance elements are welded.

From EP 0 716 427 B1 a further surface-mountable resistor is known. Also, this disclosed there component is formed of several parts, wherein a resistance element is connected at the end with terminal edge elements, which are in particular welded or soldered.

The known from the prior art surface mount resistive elements and the known manufacturing processes are very expensive and require the connection of different metal parts, for example by

Brazing. In addition, the known from the prior art resistors only a resistance element or a resistance path, also called Einzelshunt on. For a so-called multiple shunt, ie for a resistor with multiple resistance paths, several Einzelshunts are interconnected. These usually have to be successively applied to the printed circuit board and contacted in a so-called reflow soldering or wave soldering process. The invention has for its object to provide a particular surface-mountable device that is simple in design and designed to be as variable as possible and beyond that can be produced in a few manufacturing steps.

With regard to the electrical component, the object is achieved by the features of claim 1. With regard to the manufacturing method, the object is achieved by the features of claim 11th

In the case of the electrical component according to the invention, in particular a measuring resistor, at least one resistance element and a plurality of connection elements are formed from a strip strip of a metallic alloy, wherein the strip strip has a substantially tunnel-shaped middle section and ends bent at right angles inwards or outwards in the longitudinal direction, wherein at least one of the bent ends is provided with at least one slot extending at right angles from the bent end at least partially along the longitudinal direction of the tape strip. Such a formed from a single material component having at least from a side edge of a single or multiple Einschiitzungen allows in a particularly simple manner a single component with several

Resistance paths. As a result, a small component size and thus higher component density is ensured on the circuit board. Due to the elimination of connection welding between the resistance element and connecting elements, the component can be easily and quickly produced in a few manufacturing steps usually automatically. In addition, several individual components (= single shunt) are avoided by forming a plurality of resistance paths in a component. This leads to a reduction in the assembly and production costs. In addition, in particular the associated hand assembly of the circuit board and the subsequent wave soldering of the non-SMD-mountable shunt. In addition, a slotted design of such a device allows for high variability by choosing the size, shape and arrangement of the slit. Alternatively, by inserting a plurality of short slots, a single shunt having a resistance path and a plurality of connection elements for a four-conductor measurement arrangement may be formed.

In one possible embodiment, the slot passes centrally through at least the bent end, so that two separate connection elements of the same size are formed. In other words, in a symmetrically arranged slot, two essentially equal resistance paths with the same resistance value are formed. In an alternative or additional embodiment, the slot may eccentrically pass through at least the bent end and form two separate connection elements of different sizes. This allows the formation of different resistance paths with different resistance values in a particularly simple manner.

The resistance elements are usually low-resistance as so-called shunts or closing resistors and are used to measure currents. For measuring the currents, the connection elements are designed as power connection contacts. Alternatively, the connection elements can serve as measuring voltage connection contacts.

In a further advantageous embodiment of the invention, slots are provided on both sides of the tape strip at the respective end with mutually corresponding shapes and dimensions. In other words, if the tape strip on both edges or ends provided with slots which are symmetrical to each other and arranged symmetrically to each other on the respective opposite side, a simple assembly of the circuit board is made possible with the component, since the component are rotated during the assembly process can. A 180 ° rotation to correct the mounting position is thereby avoided.

In an alternative embodiment, the slot extends from one of the bent ends along the longitudinal direction of the tape strip over the u-shaped portion to the beginning of the opposite bent end. In this case, a plurality of mutually parallel slots are introduced at the respective end, which subdivides at least one of the ends of the tape strip into at least three separate connection elements, of which at least one connection element as a power connection contact and the other

Measuring voltage connection contacts are formed. This allows a current and a voltage measurement separately from the measuring resistor. In this case, two connection elements for the current and two connection elements for the voltage measurement are formed by corresponding slit of the tape strip for each resistance path or each resistance element. In addition, such a plurality of connection elements allows a secure connection of the component to the circuit board, by the thermal liquefaction of the solder due thermal stress contacted at least one of the Anschlussseiemente sure: and thus holds the device on the circuit board. For a current measurement in so-called four-wire technology or Vierpunktkontaktierung four short slots are inserted in the bent ends, wherein at each end of the tape through the slots introduced a power and a voltage terminal contact are formed.

To achieve a sufficiently good measuring resistance of the strip strip of metallic alloy is preferably formed from a copper-nickel-manganese alloy. For example, the tape strip is Isotan CuNi44 or Cu55Ni44Mn1.

For easy mounting of the component on a printed circuit board and a good surface contacting the outwardly or inwardly bent ends of the tape strip are formed and substantially flat or flat. In this case, the bent ends are surface-mountable on flat conductor tracks of an integrated circuit, wherein the connection elements are designed as power connection contacts or at least two of the connection elements as a power connection contact and the others as measuring voltage connection contacts.

In the method according to the invention for producing the electrical component, at least one flat strip of tape is severed from a material strip of a metallic alloy and a slot is introduced at one end of the strip parallel to its longitudinal direction, and then the strip is bent several times transversely to the longitudinal direction of the strip. In this case, the separation, slitting and forming of the tape strip can be carried out in a single process step by means of a combined punching and bending tool.

The advantages achieved by the invention are in particular that by means of such a different device to form a single or multiple shots from a strip of material with one or more slots of the

Assembly effort and also significantly reduced in training as Mehrfachshunt the space requirement on the circuit board. In particular, in an embodiment of the device as a single or multiple shunt in a so-called 4-wire measuring arrangement solder resistors are eliminated, since the tap of the voltage drop outside of the soldering knee by separate connection elements for the voltage measurement. Thus, a more accurate current measurement is possible. at a use of only surface mount components, the circuit board can be produced in a single reflow soldering.

Embodiments of the invention will be explained in more detail with reference to a drawing. Show:

Fig. 1 shows schematically in plan view an electrical component with several

Resistance elements and a corresponding number of connection elements, wherein a metallic strip of tape is slit at least at one end,

Fig. 2 shows schematically an electrical equivalent circuit diagram for the electrical

Component according to FIG. 1,

Fig. 3 shows schematically the electrical component according to Figure 1 in a

Front view,

4 is a schematic side view of the electrical component according to FIG. 1,

5 is a schematic perspective view of the electrical component according to FIG. 1,

Fig. 6 shows schematically an alternative embodiment for an electrical

Component as multiple shunt in a so-called four-conductor measuring arrangement,

7 shows schematically an electrical equivalent circuit diagram for the electrical component according to FIG. 6.

Corresponding parts are provided in all figures with the same reference numerals.

1 shows schematically in plan view an electrical component 1. The electrical component 1 is designed as a low-impedance measuring resistor, which is made surface mountable for a PCB assembly. In order to form a measuring resistor which is as simple as possible to manufacture and different, the component 1 is formed from a tape strip 2 which is provided at least at one end 2.1 with a slot 3 which divides the end 2.1 into two sections. The strip strip 2 is made of a metallic alloy, in particular a copper-nickel-manganese alloy, for example of an isotan-CuNiMn alloy.

By introducing the slot 3 into the end 2.1, a plurality of resistance paths with a plurality of resistance elements R1 to R3 and a corresponding number of connection elements 4.1 to 4.3 are formed. Due to the central arrangement of the slot 3 and the same size connecting elements 4.1 and 4.2, the resistive elements R1 and R2 have a substantially equal resistance value. FIG. 2 shows, by way of example, an electrical equivalent circuit diagram for the component 1 according to FIG. 1 with a centrally arranged slot 3, whereby two essentially equal resistances R1 and R2 are formed.

Alternatively to the symmetrical arrangement of the slot 3, this can also be arranged offset. This would lead to resistors R1 and R2 of different sizes. As shown in FIG. 1 by way of example by the dashed representation of further alternative or additional slots 3 which are introduced on the opposite end 2.2 of the tape strip 2, further resistance paths with the same or different resistance values can be formed. In other words, by introducing at least one slot 3 into the metallic strip strip 2, a plurality of resistive paths having a plurality of resistive elements R1 to R3 can be formed in a single component 1. Compared to the conventional device with only one resistor, the assembly effort and material costs are significantly reduced as a result.

In a further advantageous embodiment, the slots 3 on both sides of the tape strip 2 symmetrically to each other in the ends 2.1 and 2.2 be introduced. The slots 3 in shape, size and size are largely the same and therefore identical. This allows a simple and secure placement of a printed circuit board not shown, since when placing and placing the device 1 on the circuit board, a 180 ° rotation of the device 1 is possible. For a surface mounting of the component 1 on a printed circuit board, the component 1 is designed in a so-called SM D construction. This is the tape strip

2 of the component 1 bent several times, as indicated in Figure 1 by the bending folds 5.1 and 5.2. In Figure 3, the surface mount component 1 is shown in a view from the front with multiple bending folds 5.1 to 5.4. For surface contact, the tape strip 2 has a substantially tunnel-shaped, z. B. omega-shaped or U-shaped, middle section 2.3 and end in the longitudinal direction at right angles, for example, outwardly bent ends 2.1 and 2.2. Alternatively, the ends 2.1 and 2.2 may be bent inwards. The web height of the middle section 2.3 depends essentially on the specification for the overall height of the relevant printed circuit board. For example, the component 1 may have a web height of 5 mm. The bent ends 2.1 and 2.2 are flat and flat and serve the surface contact with contact surfaces of a circuit board. The undersides of the bent ends 2.1 and 2.2 in SMD technology z. B. applied to a printed circuit or printed circuit board and soldered there.

To form the resistance elements R1 to R3 of the component 1, the bent end 2.1 is provided with the slot 3, which extends perpendicularly from the bent end at least partially along the longitudinal direction of the tape strip 2. The bent ends 2.1 and 2.2 thus form a plurality of separate connection elements 4.1 to 4.3 for separate contact surfaces of a printed circuit.

FIG. 4 shows the electrical component 1 according to FIG. 1 in side view, from the side with the bent and slotted end 2.1. The slot runs

3 from the beginning of the bent end 2.1 over the bending fold 5.3 up to the bending fold 5.1. The shape, size, dimension and arrangement of the slot 3 depends essentially on the size of the predetermined resistance element R1 to R3.

FIG. 5 shows the electrical component 1 according to FIG. 1 in a perspective view. The component 1 is produced by separating or punching out the strip 2 from a strip of a metallic alloy, in particular from an isotan-CuNiMn alloy. It can simultaneously or in a subsequent step, one or more slots 3 end, on or punched on both sides of the tape strip 2 or produced in any other way. Subsequently, the slotted strip strip 2 is repeatedly bent in accordance with the predetermined bending folds 5.1 to 5.4, so that a U-shaped section 2.3 is formed with ends 2.1 and 2.2 bent at right angles therefrom in the manner of a hat brim 5. Alternatively, the ends 2.1 and 2.2 may be bent inwards. The component 1 is thus formed from a metallic material and can be produced in a single process step by simultaneous punching and bending in a stamping and bending tool. The metallic tape strip 2 may, for example, have a thickness of 0.3 mm and a length of 9 mm to 15 mm with a width of 6 mm to 11 mm or another suitable dimension. The low-resistance elements R1 to R3 are for example 4 mOhm to 8 mOhm large.

FIG. 6 shows an alternative embodiment for an electrical component 1, which is designed as a multiple shunt in a so-called four-conductor measuring arrangement. In this case, seven connecting elements 4.1 to 4.7 are formed by introducing five slots. A first slot 3.1 extends centrally from the one bent end 2.2 on the bending folds 5.1 to 5.4 in the longitudinal direction of the tape strip 2 to the beginning of the opposite end 2.1 and divides both the end 2.2 and the u-0 shaped section 2.3 in two parts, said End 2.1 remains undivided. In addition, a further four shorter slots 3.2 are introduced in the two ends 2.1 and 2.2 at the side edges, so that short end strips are formed. The lateral end strips of the ends 2.1 and 2.2 formed by the short slots 3.2 form connection elements 4.1, 4.3, 4.4 and 4.7. Due to the long slot 3.1 die5 connecting elements 4.2, 4.5 and 4.6 are formed. In this case, the slot 3.1 divides the tape strip 2 into two resistance paths and resistance elements R1 and R2, which have a common connection element 4.2 and two separate connection elements 4.5 and 4.6 as power connection contacts. The connection elements 4.1, 4.3, 4.4 and 4.7 formed by the slots 3.2 form o measuring voltage connection contacts for tapping off the voltage drop resulting from the load current.

In an alternative and unspecified form, the electrical component 1 can be designed as a single shunt in a four-conductor measuring arrangement 5, by the first slot 3.1 and at each angled end 2.1, 2.2 each account for one of the slots 3.2 and the tape strip 2 only end is provided with a short slot 3.2 per end side, so that the connection elements 4.5, 4.6 and 4.7 and 4.2 and 4.3 each form a common connection element for a resistance path.

FIG. 7 shows by way of example an electrical equivalent circuit diagram for the electrical component 1 as a multiple shunt according to FIG. 6.

LIST OF REFERENCE NUMBERS

1 component

2 tape strips

2.1 bent end

2.2 bent end

2.3 U-shaped section

3 slot

3.1 Further slots

3.2 more slots

4.1 to 4.7 connection elements

5.1 to 5.4 bending folds

R1 to R3 resistance element

Claims

claims

1. Electrical component (1), in particular measuring resistor, comprising at least one resistance element (R1 to R3) and a plurality of connection elements (4.1 to 4.7), wherein the resistance element (R1 to R3) and the connection elements (4.1 to 4.7) from a tape strip (2 ) are formed of a metallic alloy and the tape strip (2) has a substantially tunnel-shaped, central portion (2.3) and ends in the longitudinal direction at right angles bent ends (2.1, 2.2), wherein at least one of the bent ends (2.1, 2.2) at least one slot (3, 3.1 to 3.2) is provided which extends perpendicularly from the bent end (2.1, 2.2) at least partially along the longitudinal direction of the tape strip (2).

2. Electrical component according to claim 1, wherein the slot (3, 3.1) in the middle at least the bent end (2.1) passes through and at least two separate

Connection elements (4.1, 4.2) of the same size are formed.

3. Electrical component according to claim 1 or 2, wherein the slot (3, 3.2) off-center at least the bent end (2.1, 2.2) passes through and at least two separate connection elements (4.1 to 4.7) of different sizes are formed.

4. Electrical component according to one of claims 1 to 3, wherein the connection elements (4.1 to 4.7) are designed as power connection contacts and / or as a measuring voltage terminal contacts.

5. Electrical component according to one of the preceding claims 1 to 4, wherein on both sides of the tape strip (2) at the respective end (2.1, 2.2) slots (3, 3.1, 3.2) are provided with mutually corresponding shapes and dimensions.

6. Electrical component according to one of the preceding claims 1 to 5, wherein the slot (3, 3.1) of one of the bent ends (2.2) along the longitudinal direction of the tape strip (2) over the central portion (2.3) to the beginning of opposite bent end (2.1) extends.

7. Electrical component according to one of the preceding claims 1 to 6, wherein at the respective end (2.1, 2.2) a plurality of mutually parallel slots (3, 3.1, 3.2) are introduced, the respective end (2.1, 2.2) in at least three from each other divided separate connection elements (4.1 to 4.7), of which at least one connection element (4.2, 4.5, 4.6) than

Power connection contact and the others as measuring voltage connection contacts (4.1, 4.3, 4.4, 4.7) are formed.

8. Electrical component according to one of the preceding claims 1 to 7, wherein the tape strip (2) is formed of a metallic alloy of a copper-nickel-manganese alloy.

9. Electrical component according to one of the preceding claims 1 to 8, wherein the ends (2.1, 2) are bent outwards or inwards and extend substantially planar.

10. Electrical component according to one of the preceding claims 1 to 9, wherein the bent ends (2.1, 2.2) are surface mountable on flat tracks of a printed circuit, wherein the connection elements (4.1 to 4.7) as power connection contacts or at least one of the connection elements (4.1 to 4.3 or 4.2, 4.5, 4.6) are designed as a power connection contact and the others as measuring voltage connection contacts (4.1, 4.3, 4.4, 4.7).

11. A method for producing an electrical component according to one of claims 1 to 10, wherein separated from a material strip of a metallic alloy at least one flat strip of tape (2) and at least one slot (3, 3.1, 3.2) at least at one or both ends of the tape strip (2) is introduced parallel to its longitudinal direction and then the strip of tape (2) is bent several times transversely to the longitudinal direction.

12. The method of claim 11, wherein separating, slitting and forming the tape strip (2) is carried out in a single process step by means of a punching and bending tool.