Punched part for producing an electrical resistor, current sensor and corresponding production method

Abstract

The invention relates to a punched part for producing an electrical resistor, in particular a current measuring resistor, comprising a resistor element (9) consisting of a low-resistance resistive material (for example Manganin) and two electrical connection parts (10, 11) consisting of a conductor material (for example copper), wherein the resistor element (9) is arranged between the two electrical connection parts (10, 11) in the direction of current flow in such a way that the electrical current flows through the resistor element (9). In accordance with the invention, the punched part additionally has a landing area (14) for providing an integrated circuit (16) on the landing area (14) of the punched part. Furthermore, the invention comprises a current sensor comprising such a punched part and a corresponding production method.

Claims

1. A punched part for producing an electrical resistor, comprising: a) a resistor element comprising a low-ohm resistance material, b) a first current connecting part comprising a conductor material for passing an electric current into the electrical resistor, and c) a second current connecting part comprising a conductor material for passing the electric current out of the electrical resistor, wherein: d) the resistor element is arranged between the first current connecting part and the second current connecting part in a direction of current flow, so that the electric current flows through the electrical resistor, e) the punched part is punched out of a composite material strip, f) the punched part further comprises a landing area arranged to receive an integrated circuit, g) the composite material strip comprises a plurality of strips which are connected together along their longitudinal edges, h) individual strips of the composite material strip are welded together, i) the composite material strip has a middle band and two outer bands, the outer bands comprising the conductor material, while the middle band comprises the resistance material, and j) the direction of current flow in the resistor element runs parallel to a longitudinal direction of the composite material strip.

2. The punched part according to claim 1, further comprising a first voltage measuring contact and a second voltage measuring contact for measuring the electric voltage drop across the resistor element.

3. The punched part according to claim 2, further comprising a plurality of external electrical contacts for electrical contacting of the integrated circuit from outside.

4. The punched part according to claim 3, wherein the external electrical contacts are separated from the landing area for the integrated circuit and from the voltage measuring contacts by a punched-out region.

5. The punched part according to claim 2, wherein the voltage measuring contacts on the one hand and the current connecting parts on the other hand are arranged on opposite sides of the resistor element.

6. The punched part according to claim 1, wherein the two current connecting parts are laterally adjacent to the resistor element with respect to the direction of current flow in the resistor element.

7. A punched part for producing an electrical resistor, comprising: a) a resistor element comprising a low-ohm resistance material, b) a first current connecting part comprising a conductor material for passing an electric current into the electrical resistor, and c) a second current connecting part comprising a conductor material for passing the electric current out of the electrical resistor, wherein: d) the resistor element is arranged between the first current connecting part and the second current connecting part in a direction of current flow, so that the electric current flows through the electrical resistor, and e) the punched part is punched out of a composite material strip, and f) the punched part further comprises a landing area arranged to receive an integrated circuit, and g) the conductor material of the current connecting parts is copper or a copper alloy, and h) the resistance material of the resistor element is a copper alloy, and i) the resistor element is connected electrically and mechanically to the two current connecting parts, and j) the resistance material has a specific electrical resistance with a temperature coefficient of less than 5.Math.10.sup.4K.sup.1, and k) the resistance material has a specific electrical resistance of less than 2.Math.10.sup.4 .Math.m, and l) the conductor material has a specific electrical resistance of less than 10.sup.5 .Math.m, and m) the specific electrical resistance of the conductor material is lower than the specific electrical resistance of the resistance material.

8. A current sensor comprising a punched part, said punched part comprising: a) a resistor element comprising a low-ohm resistance material, b) a first current connecting part comprising a conductor material for passing an electric current into the electrical resistor, and c) a second current connecting part comprising a conductor material for passing the electric current out of the electrical resistor, wherein: d) the resistor element is arranged between the first current connecting part and the second current connecting part in a direction of current flow, so that the electric current flows through the electrical resistor, e) the punched part is punched out of a composite material strip, and f) the punched part further comprises a landing area arranged to receive an integrated circuit, wherein the landing area is integrally formed with the punched part when the punched part is punched out of the composite material strip.

9. The current sensor according to claim 8, further comprising at least one integrated circuit which is mounted on the landing area of the punched part.

10. The current sensor according to claim 9, further comprising: a) a first integrated circuit which is connected to voltage measuring contacts by bond connections in order to measure an electric voltage drop across the resistor element, b) a second integrated circuit, and c) a galvanic separation between the second integrated circuit and the voltage measuring contacts.

11. The current sensor according to claim 9, wherein the current sensor has an output circuit emitting an output signal which reflects an electric voltage drop across the resistor element.

12. The current sensor according to claim 11, wherein the output circuit comprises a sigma-delta modulator which emits a 1-bit data stream as the output signal.

13. The current sensor according to claim 11, wherein the output signal is an analogue output voltage which is proportional to the electric voltage drop across resistor element.

14. The current sensor according to claim 11, wherein the output signal is an electric current which is proportional to the electric voltage drop across the resistor element.

15. The current sensor according to claim 9, wherein the integrated circuit is connected to external contacts and to voltage measuring contacts by bond connections.

16. The current sensor according to claim 8, wherein the current sensor comprises a plurality of resistor elements configured to measure a plurality of electric currents.

17. A current sensor comprising a punched part, said punched part comprising: a) a resistor element comprising a low-ohm resistance material, b) a first current connecting part comprising a conductor material for passing an electric current into the electrical resistor, c) a second current connecting part comprising a conductor material for passing the electric current out of the electrical resistor, d) a first integrated circuit, which is connected to voltage measuring contacts by bond connections in order to measure an electric voltage drop across the resistor element, e) a second integrated circuit, f) a galvanic separation between the second integrated circuit and the voltage measuring contacts, and g) an electrically insulating sheathing which encloses the first and second integrated circuits, the bond connections and the electrical resistor, wherein: i) the resistor element is arranged between the first current connecting part and the second current connecting part in a direction of current flow, so that the electric current flows through the electrical resistor, ii) the punched part, is punched out of a composite material strip, iii) the punched part further comprises a landing area on which the first and second integrated circuits are mounted, and iv) external contacts of the first and second integrated circuits and the current connecting parts of the electrical resistor protrude from the sheathing.

18. The current sensor according to claim 17, wherein a) the insulating sheathing comprises a plastics material, and b) the integrated circuit, the bond connections and the electrical resistor are overmolded with the plastics material of the insulating sheathing.

19. A production method for producing a current sensor, comprising the following steps: a) providing a composite material strip which has two outer strips comprising a conductor material and a middle strip comprising a resistance material, the strips being connected together electrically and mechanically along their longitudinal edges, b) punching the composite material strip so that a punched part of the composite material strip remains, wherein the punched part comprises: (i) at least one resistor with a resistor element comprising the resistance material, (ii) two current connecting parts comprising the conductor material, (iii) at least one landing area arranged to receive an integrated circuit, (iv) two voltage measuring contacts for measuring an electric voltage drop across the resistor element, (v) a plurality of external electrical contacts for electrical contacting of the integrated circuit from outside, c) providing the at least one landing area on the punched part with the integrated circuit, d) electrically connecting the integrated circuit to the external contacts and to the voltage measuring contacts by bond connections, e) sheathing the electrical resistor, the integrated circuit and the bond connections with a sheathing comprising a plastics material, such that the external contacts of the into rated circuit and the current connecting parts of the electrical resistor protrude from the sheathing, and f) singularizing current sensors by separation transversely to a longitudinal strip direction of the punched part.

Description

BRIEF DESCRIPTION OF SEVERAL VIEWS OF THE DRAWINGS

(1) Other advantageous further developments of the invention will be explained in greater detail hereinbelow with reference to the figures, together with the description of the preferred embodiments of the invention. In the figures:

(2) FIG. 1 shows a perspective view of a conventional composite material strip, which is also used within the context of the invention,

(3) FIG. 2A shows a perspective view of a punched part according to the invention which has been punched out of the composite material strip according to FIG. 1 and is used to produce a plurality of current sensors,

(4) FIG. 2B shows an enlarged representation of a detail of FIG. 2A in the region of a current sensor,

(5) FIG. 3A shows a perspective view of the punched part of FIG. 2A, wherein integrated circuits have in each case been placed on the landing areas and are connected to the connecting parts and to the voltage measuring contacts by means of bond connections,

(6) FIG. 3B shows an enlarged representation of a detail of FIG. 3A in the region of a single current sensor,

(7) FIG. 4 shows a perspective view of the punched part of FIG. 3A, wherein the individual current sensors are already sheathed,

(8) FIG. 5 shows a perspective view of a finished current sensor which has been separated from the punched part according to FIG. 4,

(9) FIG. 6 shows the production method according to the invention in the form of a flow diagram, and

(10) FIG. 7 shows a schematic representation of a current-measuring resistor as is used within the scope of the invention.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

(11) FIGS. 2A and 2B show a preferred embodiment of a punched part 7 according to the invention which can be punched out of the composite material strip 1 according to FIG. 1, the punched part 7 having a plurality of blanks 8 one behind the other in the longitudinal direction of the strip, each of which blanks is to form a current sensor after further processing steps.

(12) The individual blanks 8 of the punched part 7 each have a resistor element 9 which consists of the material of the middle strip 4, so that the resistor element 9 consists of the resistance material (e.g. Manganin) of the strip 4.

(13) Each blank 8 of the punched part 7 further comprises two current connecting parts 10, 11 for passing in the current to be measured and for passing out the electric current to be measured, respectively. The two current connecting parts 10, 11 consist of the material of the strip 3 made of the conductor material (e.g. copper), so that the two current connecting parts 10, 11 also consist of the conductor material.

(14) It is to be mentioned here that the two current connecting parts 10, 11 are arranged on the same side of the resistor element 9 as a result of their production, so that the electric current is passed in and out on the same side of the resistor element 9. The current connecting part 10 hereby serves to pass the electric current into the resistor element 9, while the current connecting part 11 serves to pass the electric current out of the resistor element 9.

(15) Each blank 8 of the punched part 7 further comprises two voltage measuring contacts 12, 13 for measuring the electric voltage drop across the resistor element 9. That measured voltage is proportional to the electric current flowing through the resistor element 9 and therefore, according to Ohm's law, constitutes a measure of the electric current to be measured.

(16) Each blank 8 of the punched part 7 further has a landing area 14 which can be provided with an integrated circuit, as will be described in greater detail below.

(17) Finally, each blank 8 of the punched part 7 comprises a plurality of external electrical contacts 15 for the electrical contacting of the integrated circuit arranged on the landing area 14, the connection between the external contacts 15 and the integrated circuit being described in greater detail below. The individual external contacts 15 are separated from the landing area 14 and from the voltage measuring contacts 12, 13 by a cut-out region.

(18) FIGS. 3A and 3B show an advanced method stage of the production method according to the invention.

(19) In this method stage, the individual landing areas 14 of the individual blanks 8 are each already provided with an integrated circuit 16, and the connecting contacts of the integrated circuit 16 are connected to the associated external contacts 15 by bond connections 17.

(20) In addition, the voltage measuring contacts 12, 13 are also connected to the integrated circuit 16 by bond connections 17, so that the integrated circuit 16 is able to measure the electric voltage drop across the resistor element 9 by means of the voltage measuring contacts 12, 13.

(21) FIG. 4 shows an even further advanced method stage of the production method according to the invention. In this method stage, the individual blanks 8 of the punched part 7 are each overmolded with a sheathing 18 of thermosetting plastic, whereby the current connecting parts 10, 11 on the one hand and the external contacts 15 on the other hand protrude from the sheathing 18.

(22) Finally, FIG. 5 shows a current sensor 19 according to the invention which has been separated from the punched part 7 according to FIG. 4. The individual current sensors 19 can be singularized from the punched part 7 according to FIG. 4 by punching, for example, or by another separating method.

(23) FIG. 6 shows the production method according to the invention in the form of a flow diagram.

(24) In a first step S1, the conventional composite material strip 1, as is shown, for example, in FIG. 1, is first provided. However, it is to be noted here that the strip 2 has a greater width than the strip 3, because the strip 2 must also form the landing area 14 for the integrated circuit 16, which requires a greater width.

(25) In a further step S2, the composite material strip 1 is then punched, so that the punched part 7 according to FIG. 2A remains.

(26) In the next step S3, the punched part 7 according to FIG. 2A is then provided with the integrated circuits 16.

(27) In a further step S4, the integrated circuits 16 are then connected to the external contacts 15 and to the voltage measuring contacts 12, 13 by the bond connections 17, as is shown in FIG. 3A.

(28) In a step S5, the individual current sensors 19 are then overmolded with the sheathing 18 of the thermosetting plastic, as is shown in FIG. 4.

(29) In the last step S6, the individual current sensors 19 are then singularized by separation of the individual current sensors 19 from the punched part 7.

(30) Finally, FIG. 7 shows the direction of current flow in the current connecting parts 10, 11 and in the resistor element 9, as well as the position of the voltage measuring contacts 12, 13. It will be seen from this representation that the current connecting parts 10, 11 are arranged on one side of the resistor element 9, while the voltage measuring contacts 12, 13 are situated on the opposite side of the resistor element 9.

(31) The invention is not limited to the preferred embodiments described above. Rather, a plurality of variants and modifications are possible which likewise make use of the concept according to the invention and therefore fall within the scope of protection. In particular, the invention also claims protection for the subject-matter and the features of the dependent claims independently of the claims on which they are dependent.

LIST OF REFERENCE NUMERALS

(32) 1 Composite material strip

(33) 2 Strip made of conductor material

(34) 3 Strip made of conductor material

(35) 4 Strip made of resistance material

(36) 5 Longitudinal edge of the strip made of the resistance material

(37) 6 Longitudinal edge of the strip made of the resistance material

(38) 7 Punched part

(39) 8 Blank

(40) 9 Resistor element

(41) 10 Current connecting part

(42) 11 Current connecting part

(43) 12 Voltage measuring contact

(44) 13 Voltage measuring contact

(45) 14 Landing area for the integrated circuit

(46) 15 External contacts of the integrated circuit

(47) 16 Integrated circuit

(48) 17 Bond connections

(49) 18 Sheathing

(50) 19 Current sensor