DE102014016248A1 - Printed circuit board with at least one four-pole current measuring element - Google Patents

Abstract

Printed circuit board having at least one (four-pole) current measuring element, which consists of at least one high-current conductor, which is connected to two spaced power connections, between which two spaced measuring terminals are arranged, wherein the (quadrupole) current measuring element is designed as a shunt and in the structure of the circuit board is integrated.

Description

The invention relates to a printed circuit board with at least one four-pole current 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 .mu.m to 400 .mu.m 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 ultrasound surface and semi-cold contacted Dickkupferelemente (profile laying technology) 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, for example, with the WO 2014/099094 A1 shown. 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 suitable copper profiles are used as a shunt, which allow currents to flow in the range of> 30 amperes.

• 1. Es fällt die Fläche, die der Shunt an der Oberfläche benötigt, für Bestückungszwecke weg;
• 2. Es ist eine separate Bestückung der Leiterplatte notwendig;
• 3. Die zusätzliche Anbringung des Bauteils auf der Leiterplatte verursacht zusätzliche Kosten, erhöht die Bauhöhe der Leiterplatte und verschlechtert die Bearbeitbarkeit der Leiterplatte. Des Weiteren kann der Shunt nicht als integraler Bestandteil der Verschaltung an der Leiterplatte verwendet werden. Er ist jeweils immer nur ein isoliertes Messelement.

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 interconnection 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 connections through which the current to be measured flows and of two measuring connections arranged in the region of this measuring element, between which the voltage drop is measured, whereby a defined resistance exists between the two measuring connections.

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 it is now possible for the first time to define a four-pole current measuring element in any high current-carrying printed circuit board construction 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, so to speak, as cooling elements for possibly in operation used heating 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.

Another advantage of the invention is that the dimension and geometry of the quadrupole current measuring element can be arbitrarily defined, i. H. Any printed conductor routing in the printed circuit board which relates to a high-current conductor can be redefined as a quadrupole 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. As 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:

1 FIG. 4 shows an arrangement of a prior art four-pole current measurement. FIG

2 : The top view of a four-pole current measuring element, which is integrated in a printed circuit board assembly

3 : the section according to the line III-III in 2

4 Section according to the line IV-IV in 2

5 : schematized a section through a circuit board similar to the 2

6 : the 90 ° rotated section through the PCB according to 5

7 : A schematic representation of the arrangement of several Vierpolstrommesselementen in a printed circuit board assembly

8th : a similar representation as 7 in rotated form

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

In 1 In general, the principle of four-pole current measurement is shown.

On a high current conductor 5 are two spaced measuring ports 3 . 4 arranged. Furthermore, there are two spaced power connections 6 . 7 on the high current conductor 5 connected, between which a current through the high current conductor 5 flows.

In the area of the high current conductor 5 are measuring connections 3 . 4 electrically conductive with the high current conductor 5 connected and form a measuring distance between them 11 , It is important that in the area of the measuring branch the voltage drop between the measuring terminals 3 . 4 is measured, so the current through the high current conductor 5 to determine.

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

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

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

In the embodiment shown are in the high current conductor 5 introducing power connections 6 formed profiled round and shaped as Kontaktierungskanäle, as based on the 5 and 6 is still shown.

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

Depending on how high the current is between the power connections 6 . 7 flows, a voltage drop occurs between the measuring terminals 3 . 4 and this voltage drop is tapped on the test leads.

The copper inner layer 2 is with the high-current conductor according to the invention 5 contacted at the said places. 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 μm to 1.5 mm.

In the 3 and 4 is shown that the high-current conductor 5 smaller in size than the copper inner layer attached to it 2 , However, the invention is not limited thereto. However, this is not necessary for the solution; the copper inner layer 2 could also be smaller in size than the dimension of the high current conductor 5 in terms of 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 also directly on the high-current conductor 5 can be attached. The copper inner layer 2 can then be omitted.

The 5 shows as an embodiment a section through a multi-layer printed circuit board, which in turn is shown here as a non-limiting embodiment that the high-current conductor 5 on its underside with the copper inner layer 2 is connected, it is only necessary, the electrical contact in the field of measuring terminals 3 . 4 provided.

In the illustrated embodiment, the power is via the connection cable 8th as measuring current 12 fed in and over two contacting Hochstromkontaktierungen 11 , which are channel-shaped, in the high current conductor 5 initiated where he is in the longitudinal direction of the high current conductor 5 flows and causes a voltage drop to be detected.

On the opposite side is the power connection 7 designed in the same way as the power connector 6 , so the power on the connection cable 9 flows out of the circuit again.

It is important that at the measuring connections 3 . 4 that are electrically conductive with the high current conductor 5 connected, a measuring distance 11 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.

In 6 is further shown that in turn the copper inner layer 2 at the bottom of the high current conductor 5 is arranged and only the high-current conductor with the Hochstromkontaktierungen 10 is contacted. It is possible, even the copper inner layer 2 to supply the high current, but this is not necessary for the solution. The only important thing is that at the bottom or anywhere in the area between the power connections 6 . 7 of the high current conductor 5 measuring connections 3 . 4 in a well-defined measuring distance 11 are arranged, between which the voltage drop is measured.

In the general description has already been noted that the copper inner layer 2 completely eliminated, provided that the measuring connections 3 . 4 directly as electrical contacts on the high current conductor 5 are arranged.

The contact surface 14 to 6 between the high current conductor 5 and the copper inner layer 2 does not have to be electrically conductive, but it may 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 embodiments shown by 7 and 8th is shown that also several separately arranged Vierpolstrommesselemente 20 . 20a . 20b can be integrated in any printed circuit board structure. They can be arranged side by side or on top of each other, as in 8th is shown.

As a further essential embodiment, however, shows the 9 in 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 namely provided that any high-current conductor track, the in 9 is shown as a high current conductor 5 is used. Here, the first four-pole current measuring element would be the first exemplary embodiment 20 as a U-shaped high current conductor 5 formed, and it can be seen that it is only essential, between two measuring terminals 3 . 4 a defined measuring distance 11 to measure the voltage drop between them. The measuring connections 3 . 4 can also be arranged at another location of the high current conductor, as for example in the 9 With 3a and 4a is shown.

The 9 shows as a second embodiment, a four-pole current measuring element, which directly from a high current conductor 5 which is incorporated in the printed circuit board assembly and which is intended to perform other electrical tasks. For example, with the high current becomes a component 17 supplied and on the circuit board 1 are still more tracks 16 arranged.

Thus, any, high-current conductor track, as here the high-current conductor 5 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 11 is given, at which the voltage drop is measured.

Thus, it is possible in any PCB assembly, already used there and for other circuit tasks associated high current conductor 5 in addition to form as Vierpolstrommesselement.

LIST OF REFERENCE NUMBERS

1

circuit board

2

Copper inner layer

3

measuring connections

4

measuring connections

5

High-current conductors

6

power connection

7

power connection

8th

connection cable

9

connection cable

10

Hochstromkontaktierung

11

measuring distance

12

measuring current

13

14

contact surface

15

contact point

16

conductor tracks

17

component

18

measuring connection

19

measuring connection

20

Vierpolstrommesselement

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been 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.

Cited patent literature

• WO 2014/099094 A1 [0008]

Claims (10)

Printed circuit board ( 1 ) with at least one (four-pole) current measuring element ( 20 ), which consists of at least one high current conductor ( 5 ), which is provided with two spaced power connections ( 6 . 7 ) between which two spaced measuring terminals ( 3 . 4 ) are arranged, characterized in that the (quadrupole) current measuring element ( 20 ) is formed as a shunt and in the structure of the circuit board ( 1 ) is integrated. 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. Printed circuit board ( 1 ) according to claim 1 or 2, characterized in that the printed circuit board ( 1 ) at least one copper inner layer ( 2 ), which at least in the region of the power connections ( 6 . 7 ) and the measuring connections ( 4 . 5 ) with the high-current conductor ( 5 ) connected is. 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 with at least two connecting cables ( 8th . 9 ) are connected to power in the high current conductor ( 5 ) in and / or out. Printed circuit board ( 1 ) according to one of claims 1 to 4, characterized in that the measuring connections ( 3 . 4 ) with a defined measuring distance ( 11 ) conductive with the high current conductor ( 5 ) are connected. Printed circuit board ( 1 ) according to one of claims 1 to 5, characterized in that the measuring terminals ( 3 . 4 ) even directly on the high-current conductor ( 5 ) are designed as a contacting bore. 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 ) and starting from this contact point removes the measuring connections ( 3 . 4 ) are arranged. 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. Method for producing a printed circuit board ( 1 ) with at least one (four-pole) current measuring element ( 20 ), which has at least one high-current conductor ( 5 ) provided with two spaced electrical connections ( 6 . 7 ) between which two spaced measuring terminals ( 3 . 4 ), characterized in that in a separate manufacturing process the four-pole current measuring elements ( 20 ) which is subsequently used in the production of the printed circuit board ( 1 ) is integrated in the printed circuit board assembly. Method for producing a printed circuit board ( 1 ) with at least one (four-pole) current measuring element ( 20 ), which has at least one high-current conductor ( 5 ) provided with two spaced electrical connections ( 6 . 7 ) between which two spaced measuring terminals ( 3 . 4 ) are arranged, characterized in that in the assembly of the printed circuit board ( 1 ) at least one high-current conducting track ( 5 ), at which the spaced measuring terminals ( 3 . 4 ) with a measuring distance ( 11 ) to be ordered.

Images