EP3216326A1

EP3216326A1 - Circuit board comprising at least one quadrupole current measuring element

Info

Publication number: EP3216326A1
Application number: EP15793704.6A
Authority: EP
Inventors: Johann Hackl; Stefan Hörth; Norbert REDL
Original assignee: Hausermann GmbH
Current assignee: Hausermann GmbH
Priority date: 2014-11-04
Filing date: 2015-10-30
Publication date: 2017-09-13
Also published as: DE102014016248A1; DE102014016248B4; WO2016070978A1

Abstract

Disclosed is a circuit board (1) comprising at least one (quadrupole) current measuring element (20) consisting of at least one high-current conductor that is connected to two spaced-apart current terminals (6, 7) between which two spaced-apart measuring terminals (3, 4) are arranged; the (quadrupole) current measuring element (20) is designed as a shunt and is integrated into the structure of the circuit board (1).

Description

Printed circuit board with at least one four-pole current measuring element

The invention relates to a printed circuit board with at least one Vierpolstrom- measuring element.

Printed Circuit Boards (PCBs), printed wiring boards (PWBs), printed circuit boards or printed circuit boards are used for wiring or electrical connection and mechanical fastening of electrical or electronic components (el. Components or el. Components). For this purpose, the electrical components are mechanically fastened and electrically contacted radially in the holes of the printed circuit board. Furthermore, they can be mounted on the surface (surface mount technology SMT or surface mount devices SMD) or buried in inner layers (burried components).

The progressive development of the printed circuit boards shows on the one hand that the el. Components are becoming smaller and more complex, which leads to a high degree of heating. Thus, the demand for dissipation of the heat loss of el. Constituents steadily increases. Furthermore, ever higher currents are provided or required on relatively small printed circuit board surfaces. The field of application for this purpose may be, for example, a modern LED element in the EV (Electro Vehicle) sector or in general in power electronics. It is therefore necessary to dimension the copper cross-sections of the wiring structures on and in printed circuit boards to the planned currents, so that the heating of the copper lines per se remains within planned limits. Furthermore, the copper structures are actively used to dissipate the heat loss of el. Components.

In addition to the thick copper technology with copper structures of typically 200 pm to 400 pm copper thickness (etch-technically produced and / or galvanically reinforced) and the integration of stamped copper structures in printed circuit boards was a high-current and thermal management PCB technology based on ultrasonic flat and semi-cold contacted thick copper elements (Profile laying technique) developed on standard etched copper structures.

From the prior art, a four-pole current measurement in printed circuit boards is known. The four-pole current measurement essentially consists of a four-point or four-peak measurement. For this purpose, a so-called shunt is used, which is a low-resistance electrical resistance and is used to measure the electric current. In general, the shunt has two power connections and two connections for measuring the voltage drop.

The shunt acts as a measuring resistor, with the current flowing through the shunt causing a voltage drop proportional to it, which is measurable. Usually very low voltage drops are measured with suitable measuring equipment and the current is determined according to Ohm's law.

As the metal profile shunt material, copper may be used, or copper alloys with, for example, manganese, nickel, aluminum and the like having preferably a low temperature coefficient. In principle, however, with a selected shunt material, the temperature coefficient can be taken into account or corrected by measuring the temperature in the measurement result of the current.

Previously, in a current measurement in printed circuit board technology was only known that a shunt is applied to the outer surface of the multilayer printed circuit board and there takes place a current measurement. Such an embodiment is shown, for example, with WO 2014/099094 A1. In such shunts, there is the problem that at high currents, the shunt heats up in an undesirable manner. Such a warming should be prevented as much as possible. For this reason, high-current copper profiles are used as a shunt, which allow currents in the range of> 30 amperes to flow through. The arrangement of a shunt on the surface of a circuit board, however, has significant disadvantages:

1 . The area required by the shunt on the surface falls away for assembly purposes;

2. It is a separate assembly of the circuit board necessary;

3. The additional attachment of the component on the circuit board causes additional costs, increases the height of the circuit board and deteriorates the workability of the circuit board.

Furthermore, the shunt can not be used as an integral part of the shading on the circuit board. He is always only an isolated measuring element.

The invention is therefore based on the object to simplify or improve a printed circuit board with a measuring element.

To solve the problem, the invention is characterized by the technical teaching of claim 1.

An essential feature of the invention is that the (Vierpolstrom-) measuring element is integrated as a shunt in the printed circuit board assembly.

This arrangement of the measuring element has the advantage that the integrated circuit board is already provided during production with such a measurement structure. Thus, at least one (Vierpolstrom-) measuring element can be integrated in the printed circuit board assembly.

In a preferred embodiment, the four-pole current measuring element is part of a conductor track guide. This means that any conductor track in the circuit board that is suitable for high current application can be converted as a quadrupole current measuring element. The four-pole current measuring element consists of two high-current terminals through which the current to be measured flows and of two measuring terminals arranged in the region of this measuring element, between which the voltage drop is measured, whereby a defined resistance exists between the two measuring terminals.

It is crucial that the measuring connections are always arranged at the same distance in order to achieve a constant resistance between the measuring connections.

The present invention contemplates several different embodiments, all of which fall within the scope of the present invention.

In a first embodiment of the invention, one or more (quadrupole current) measuring elements are produced in a (separate) production process, which are integrated in single or multiple form during the production of the printed circuit board in the printed circuit board assembly. It is therefore defined four-pole current measuring elements, which are integrated in addition to the other elements in the printed circuit board assembly.

In a second embodiment of the invention, however, it is provided that one chooses a high-current conductor in the design and the assembly of the circuit board and only at certain, defined locations, to arrange the measurement connections necessary for the measurement. In this case, only the distance between the measuring connections with respect to other conductor tracks must always be the same.

This means that one can define ad hoc during the development in the printed circuit board, a specific, high-current conductor track as Vierpolstrommesselement by now arranging the measurement terminals according to the invention for tapping the measurement voltage in the interior between the high-current terminals.

This makes it possible in a simplified manner to integrate a four-pole current measuring element next to any high-current-carrying printed circuit board construction. For the formation of a Vierpolstrommesselementes so only four points or points on a high-current copper profile are necessary, which are preferably the external connection points for the connection of a high current and the well-defined contact on the high current conductor by means of measuring connections. The contacting or mounting of measuring connections on this high current conductor can be done in various embodiments.

In one embodiment, it is provided that the measuring terminals themselves are designed directly on the high-current conductor as a contacting bore. The measuring connection or the measuring line can be connected directly to this contacting hole.

In a further embodiment of the invention, it is provided that only one contact point is arranged on the surface of the high-current conductor and, starting from this contact point, the measuring lines are arranged. Such a contact point may, for. B. be formed as a contacting channel.

It is important that you only have to attach the contact to the high-current conductor, but can carry out the removal of the test leads in another level of the multilayer printed circuit board.

The contacting can take place, for example, via ultrasound, via friction welding, via soldering, via galvanic copper plating and the like. The essential advantage of the invention is therefore that for the first time it is possible to define a four-pole current measuring element in any high-current-carrying printed circuit board structure by simply providing a measuring distance for the attachment of measuring terminals for measuring the voltage drop in this area in the space between two high-current connection points becomes. With the given technical teaching, there is the significant advantage that now the printed circuit board assembly can be kept very small, because there are no additional elements necessary because you can define any high-current conductive trace as Vierpolstrommesselement.

Another advantage of the invention is the cost-effective production and the favorable heat dissipation, because the surrounding components and components of the multilayer printed circuit board are used as it were as cooling elements for the possibly warming in operation high-current conductor, whereby a favorable heat dissipation is given.

The attachment of the power connections to the high current conductor can be done in various ways.

In a preferred embodiment, it is provided that these connections are each led out of the front of the multi-layer printed circuit board and thus can be contacted directly with a live connection cable.

In another embodiment, it may be provided that these terminals are bent up as terminal lugs and thereby form contact elements to subsequent power cables.

In a further embodiment, it can be provided that the power connections for the high-current conductor are integrated in the circuit board itself. Here are z. B. current-carrying guide channels, which have suitable holes for a press-fit.

A further advantage of the invention is that the dimension and the geometry of the four-pole current measuring element can be defined as desired, ie any arbitrary conductor track guidance in the printed circuit board, which relates to a high-current conductor track, can be redefined as four-pole current measuring element. By integrating the four-pole current measuring element in the printed circuit board, the outer surface of the printed circuit board is kept free of internals and can be used for additional equipping.

In a development of the invention, it is provided that an additional temperature compensation is integrated. This temperature compensation is based on the fact that the temperature of the high-current conductor undesirably increases when it is flowed through with a high current, which in turn influences the voltage drop between the measurement influences. This influence is to be compensated.

In a preferred embodiment of the invention, it is provided that a temperature compensation takes place by measuring the temperature on or at the high-current conductor. Such a measurement of the temperature may, for. B. by any temperature measuring element, such as. Example, a thermistor, a PT100 element or the like.

A preferred (production) process sequence can proceed as follows. The multi-layer printed circuit board is formed with the integerierten metal profile so that the metal profile is exposed from one side or from both sides of the multi-layer printed circuit board and can be connected electrically low impedance. It can also be a part of the metal profile on one side or both sides are exposed and executed angled so that one or two parts of the metal profile shunt angled by means of screws or clamps or soldering or pressing or welding can be contacted electrically.

In such a four-point or four-wire current measurement, the two contacts for measuring the generally very small voltage drop through the copper structure of a layer or contacting by at least one hole with any layers of the circuit board, can be perceived and so can very easily corresponding components are arranged for current measurement on the circuit board. The subject of the present invention results not only from the subject matter of the individual claims, but also from the combination of the individual claims with each other.

All information and features disclosed in the documents, including the abstract, in particular the spatial design shown in the drawings, are claimed to be essential to the invention insofar as they are novel individually or in combination with respect to the prior art.

In the following the invention will be explained in more detail with reference to drawings showing only one embodiment. Here are from the drawings and their description further features essential to the invention and advantages of the invention.

Show it:

Figure 1: an arrangement of a Vierpolstrommessung after the

PRIOR ART FIG. 2 shows the top view of a four-pole current measuring element, which is shown in FIG

a printed circuit board assembly is integrated

3 shows the section along the line III-III in Figure 2 Figure 4 section along the line IV-IV in Figure 2

FIG. 5 schematically shows a section through a printed circuit board similar to FIG. 2, FIG. 6, of the section rotated by 90 ° through the printed circuit board according to FIG. 5

Figure 7 is a schematic representation of the arrangement of several

Four-pole current measuring elements in a printed circuit board construction FIG. 8: a representation similar to FIG. 7 in a rotated form

Figure 9: a plan view of a broken printed circuit board assembly with the introduction of a Vierpolstrommesselementes

In Figure 1, the principle of Vierpolstrommessung is generally shown.

On a high current conductor 5 two spaced measuring terminals 3, 4 are arranged. Further, two spaced apart power terminals 6, 7 are connected to the high-current conductor 5, between which a current flows through the high-current conductor 5.

In the region of the high-current conductor 5, measuring terminals 3, 4 are electrically conductively connected to the high-current conductor 5 and form a measuring distance 11 between them. It is now important that the voltage drop between the measuring terminals 3, 4 is measured in the region of the measuring branch so as to determine the current through the high-current conductors 5.

So far, it was only known to mount such a four-pole current measuring element, as shown in the prior art, outside of a printed circuit board assembly, which is associated with an increased effort. This has already been shown in the general description introduction.

According to the invention, a four-pole current measuring element 20 is now integrated in a printed circuit board construction. As a first embodiment, Figure 2 shows a circuit board 1, which may consist of any material and may have any number of layers.

It is now important that integrated in the circuit board assembly in the region of any position, which may be an inner or outer layer, the Vierpolstrommesselement invention 20. In the embodiment shown it consists from a separate element, which consists essentially of a copper inner layer 2, which is formed as a flat copper track.

The copper inner layer has a thickness of about 35 μ to 150 μ. The copper inner layer 2 is connected in one embodiment in the region of the electrical connections 6, 7 and the measuring terminals 4, 5 with the high-current conductor 5 designed as a shunt.

In the exemplary embodiment shown, the current connections 6 introduced into the high-current conductor 5 have a profiled shape and are shaped as contacting channels, as will be illustrated with reference to FIGS. 5 and 6.

At the measuring terminals 4, 5 set test leads that lead to a measuring arrangement, not shown, which is able to detect the voltage drop between the two measuring terminals 3, 4 and evaluate.

Depending on how high the current that flows between the power terminals 6, 7, there is a voltage drop between the measuring terminals 3, 4 and this voltage drop is tapped on the measuring lines.

The copper inner layer 2 is contacted with the high-current conductor 5 according to the invention at said locations. The high-current conductor itself is suitable for carrying a high current in the range of more than 30 amperes and is chosen in its dimension and its dimensions so that it does not heat up significantly at the flow of a high current.

As an example, it is stated that such a high current conductor has a width of 1 to 20 mm, a length of 10 to 100 mm and a thickness of 100 μιη to 1, 5 mm.

In FIGS. 3 and 4 it is shown that the high-current conductor 5 is smaller in its dimensions than the copper inner layer 2 fastened thereon however, the invention is not limited. However, this is not necessary for the solution; the copper inner layer 2 could also be dimensioned smaller than the dimension of the high-current conductor 5 with respect to the length and width.

In other embodiments, which are not shown here, it is also possible to omit the copper inner layer, because the corresponding terminals 6, 7 and 3, 4 can also be mounted directly on the high-current conductor 5 itself. The copper inner layer 2 can then be omitted.

As an exemplary embodiment, FIG. 5 shows a section through a multilayer printed circuit board, again showing as a non-limiting exemplary embodiment that the high-current conductor 5 is connected on its underside to the copper inner layer 2, wherein it is only necessary for the electrical contacting in FIG Provision area of the measuring connections 3, 4.

In the exemplary embodiment shown, the current is supplied via the connecting cable 8 as a measuring current 12 and introduced into the high-current conductor 5 via two contacting Hochstromkontaktie- ments 1 1, where it flows in the longitudinal direction of the high-current conductor 5 and causes a voltage drop to be detected.

On the opposite side of the power connector 7 is formed in the same manner as the power connector 6, so that the current on the connecting cable 9 flows out of the circuit again.

It is important that at the measuring terminals 3, 4, which are electrically conductively connected to the high-current conductor 5, a measuring distance 1 1 is defined at which there is a voltage drop. This voltage drop is dependent on a current flow through the high current conductor and thus a direct measure of the current that is to be detected.

FIG. 6 also shows that, in turn, the copper inner layer 2 is arranged on the lower side of the high-current conductor 5 and only the high-current conductor is contacted with the Hochstromkontaktierungen 10. Although it is possible to supply the copper inner layer 2 with the high current, but this is not necessary for the solution. Decisive is only that at the bottom or at any point in the area between the power terminals 6, 7 of the high current conductor 5 measuring terminals 3, 4 are arranged in a well-defined measuring distance 1 1, between which the voltage drop is measured.

In the general description it has already been pointed out that the copper inner layer 2 can also be completely eliminated, provided that the measuring terminals 3, 4 are arranged directly as electrical contacts on the high-current conductor 5.

The contact surface 14 according to FIG. 6 between the high-current conductor 5 and the copper inner layer 2 therefore does not have to be electrically conductive, but it may be designed to be electrically conductive. The contact point 15 is the contact point between the copper inner layer 2 and the high current conductor. 5

In the exemplary embodiments shown in FIGS. 7 and 8, it is shown that a plurality of quadrupole current measuring elements 20, 20a, 20b arranged separately from one another can also be integrated into any printed circuit board construction. They can be arranged side by side or one above the other, as shown in FIG.

As a further essential embodiment, however, FIG. 9 shows that it is not necessary to integrate a four-pole current measuring element as a separate component in a printed circuit board. In another embodiment, it is provided that any high-current conducting track, which is shown in Figure 9, is used as a high-current conductor 5. Here, as the first exemplary embodiment, the first four-pole current measuring element 20 would be designed as a U-shaped high-current conductor 5, and it can be seen that it is only essential to provide a defined measuring distance 11 between two measuring terminals 3, 4 in order to measure the voltage drop therebetween. The Measuring connections 3, 4 can also be arranged at another point of the high current conductor, as shown for example in FIG. 9 with FIGS. 3a and 4a.

FIG. 9 shows, as a second exemplary embodiment, a four-pole current measuring element which consists directly of a high-current conductor 5, which is integrated in the printed circuit board structure and which is intended to carry out other electrical tasks. For example, a component 17 is supplied with the high current and further printed conductors 6 are arranged on the printed circuit board 1.

Thus, any high-current conducting track, such as here the high-current conductor 5 can be used as Vierpolstrommesselement, because in the region of this element again two spaced measuring terminals 3, 4 are present, between which the measuring distance is given 1 1, at which the voltage drop is measured.

Thus, it is possible in any printed circuit board structure to additionally form a high current conductor 5 already used there and for other circuit tasks as a quadrupole current measuring element.

Zeichnunqslegende

circuit board

Copper inner layer

measuring connections

High-current conductors

power connection

Stromänschluss

connection cable

Hochstromkontaktierung

measuring distance

measuring current

contact surface

contact point

conductor tracks

component

measuring connection

Vierpolstrommesselement

Claims

claims

1 . Printed circuit board (1) having at least one (quadrupole) current measuring element (20), which consists of at least one high current conductor (5) which is connected to two spaced electrical connections (6, 7), between which two spaced measuring terminals (3, 4) are, characterized in that the (quadrupole) current measuring element (20) is designed as a shunt and is integrated in the structure of the printed circuit board (1).

2. Printed circuit board (1) according to claim 1, characterized in that the

Four-pole current measuring element (20) is part of a conductor track guide.

3. Printed circuit board (1) according to claim 1 or 2, characterized in that the printed circuit board (1) has at least one copper inner layer (2), which at least in the region of the electrical connections (6, 7) and the measuring terminals (4, 5). is connected to the high current conductor (5).

4. printed circuit board (1) according to one of claims 1 to 3, characterized in that the printed circuit board (1) at least two Hochstromkontaktierungen

(10), which are connected to at least two connecting cables (8, 9) in order to feed and / or dispense power into the high-current conductor (5).

5. printed circuit board (1) according to one of claims 1 to 4, characterized in that the measuring terminals (3, 4) with a defined measuring distance

(1 1) are conductively connected to the high current conductor (5).

6. Printed circuit board (1) according to any one of claims 1 to 5, characterized in that the measuring terminals (3, 4) are themselves designed directly on the high current conductor (5) as a contacting bore.

7. printed circuit board (1) according to one of claims 1 to 6, characterized in that only one contact point on the surface of the high current conductor (5) is arranged and starting from this contact point away from the measuring terminals (3, 4) are arranged.

8. printed circuit board (1) according to one of claims 1 to 7, characterized in that in the region of the high-current conductor (5), a temperature measuring element is arranged.

9. A method for producing a printed circuit board (1) having at least one (four-pole) current measuring element (20) which has at least one high-current conductor (5) which is connected to two spaced electrical connections (6, 7), between which two spaced measuring terminals ( 3, 4) are arranged, characterized in that the Vierpolstrommesselemente (20) is produced in a separate manufacturing process, which is then integrated in the manufacture of the printed circuit board (1) in the printed circuit board assembly.

10. A method for producing a printed circuit board (1) having at least one (four-pole) current measuring element (20) which has at least one high-current conductor (5) which is connected to two spaced electrical connections (6, 7) between which two spaced measuring terminals (20). 3, 4) are arranged, characterized in that in the assembly of the printed circuit board (1) at least one high-current conductor track (5) is selected, at which the spaced measuring terminals (3, 4) with a measuring distance (1 1) are arranged.