DE10011974A1 - Micro-technological current sensor assembly, has conductors arranged closely in line on run-around frame and fixed by insulating plastic cover, after which run-around frame is removed - Google Patents

Abstract

Multiple conductors (1) are arranged with a minimum gap in-between, on a run-around frame (1A). A plastic jacket which serves as an insulator covers the conductors and fixes them relative each other, after which the run-around frame is removed.

Description

The invention relates to the construction and connection technology of a current sensor of the micro system technology.

With specially developed current sensors, the currents are measured via their magnetic field with magnetic field sensors (Hall sensors), which are implemented in a standard CMOS technology. By using the standard technology, the sensors can be manufactured inexpensively and extensive signal processing is possible, ie additional functions can be given to the sensor, such as

• - separation of leakage currents,
• - measuring and displaying the conductor currents,
• - Setting predeterminable thresholds, which, when reached, are used for warning or down switching and can be used for load management,
• Control of a data interface,
• - Check of PE and N conductors.

When measuring the electrical current via the magnetic field measurement with z. B. Hallsen sensors or the like, there is a whole range of possible construction variants that can be used measurable measuring range, the achievable resolution and the realizable insulation strength under divorce.

In the simplest version, the current conductor is implemented directly on the chip. By the With this arrangement, the small distance between the conductor and the sensor can be achieve maximum accuracy. The maximum measuring current in this case is the current load capacity of the metallization is limited.

Higher currents can be measured if the current conductor is not integrated monolithically becomes. In principle, very high currents can be measured with external conductors. Which he Reachable resolution depends on the distance between the sensor chip and the center of the conductor from.

With multi-pole sensors, the short distance between the conductors is equally important like the close distance between the current conductor and the sensor chip. Here too, a minor influence Distance the sensitivity to external fields.

There is therefore a requirement that the Hall sensors be brought close to the current conductors become, d. H. a close spatial connection of high voltages (a few hundred volts) and high currents (in the event of a short circuit a few kA) on the network side with the low voltages and flows of silicon technology on the sensor side. Between these different  Pages must be one despite the small distance required by the measuring technology safe electrical isolation.

The position of the current conductors must be as precise as possible over the entire temperature range and the entire operating time can be kept. Mechanical influences can act like the electrodynamic forces from the parallel, narrow conductor routing and the high Short-circuit currents, or thermal influences due to the high conductor currents and the different coefficients of thermal expansion of the materials used.

The object of the invention is to find a construction and connection technology that the ge wrestle distance between the sensors and the conductors, as well as the conductors to each other leaves and thereby the electrical and mechanical strength over the entire service life guaranteed.

This object is achieved by the characterizing part of the patent ches 1 solved.

The short distances to the Hall sensors and to each other are determined with a special Design of the excitation conductor and through the overhead mounting of the sensor chip (flip Chip assembly) reached.

The invention is illustrated by the figures.

It shows:

Fig. 1 the current conductor 1 manufactured in conjunction with a peripheral frame 1 A.

Fig. 2, the current conductor 1 provided with a plastic sheath 2 after the frame 1 A has been separated.

Fig. 3 shows a section through the current conductor 1 provided with a plastic sheath 2 .

Fig. 4 shows the structural unit of the current conductor 1 with a plastic sheath 2 , inserted into a ceramic plate 4 on which the sensor and the components of the switching power supply 5 are arranged.

Fig. 5, the assembly of the current conductor 1 with plastic sheathing 2 , in MID technology equipped with the sensor 3 and the components of the switching power supply 5 .

With MID technology, LCP encapsulation is also used as insulation, conductor fixie tion and circuit carrier used for flip-chip assembly.

In this technology, the three-dimensional injection molded circuit carriers will be high-temperature resistant thermoplastics with structured metallizations, d. H. Conductor tracks and contact pads are applied to the plastic.  

The advantages lie on the one hand in the higher security of the dielectric strength - homogeneous structure, fewer separation points between different materials - on the other hand in the simpler design option of the current conductor, which is on one level at the sensor introduced and can therefore be manufactured more cost-effectively.

Reference list

1

Conductor

1

A frame

2

Plastic wrapping

3rd

sensor

4

Ceramic plate

5

Switching power supply components

Claims (5)

1. Construction and connection technology of a current sensor of microsystem technology, characterized in that the current conductors ( 1 ), which have a cross-sectional reduction corresponding to the permissible current carrying capacity at the measuring point and the smallest possible distance from each other, manufactured in conjunction with a peripheral frame ( 1 A) are, the current conductor ( 1 ) are then provided with a plastic sheath ( 2 ), the plastic sheathing also serves as insulation and conductor fixation, and then the frame ( 1 A) is separated. 2. Construction and connection technology of a current sensor of microsystem technology according to claim 1, characterized in that the current conductors ( 1 ) are preferably extrusion-coated with a liquid-crystalline (LCP) polymer. 3. Construction and connection technology of a current sensor of microsystem technology according to claim 1 and 2, characterized in that the plastic sheath ( 2 ) serves as insulation, conductor fixing and circuit carrier for the flip-chip assembly of the sensor ( 3 ). 4. Construction and connection technology of a current sensor of microsystem technology according to claim 1, characterized in that the plastic sheath ( 2 ) of the current conductor ( 1 ) is designed so that both can be arranged in a cutout of a ceramic plate ( 4 ), one side the ceramic plate is covered with the plastic of the casing and the sensor ( 3 ) and the components of the switching power supply 5 are arranged on the opposite side of the ceramic plate ( 4 ). 5. Construction and connection technology of a current sensor of microsystem technology according to claim 1 and 3, characterized in that the plastic sheath ( 2 ) at the same time as insulation, conductor fixing and circuit carrier for the flip-chip assembly of the sensor ( 3 ), and for receiving further functional electronic or mechanical components.