DE10065965B4 - Production method for a current sensor of the microsystem technology - Google Patents

Abstract

Production method for a current sensor of microsystem technology,
with the steps that
- The current conductor (1), which have a cross-sectional reduction according to the allowable current carrying capacity at the measuring point and a minimum possible distance from each other, are produced in conjunction with a peripheral frame (1A);
- The conductors (1) are then provided with a plastic sheath (2), wherein the plastic sheath serves as insulation and conductor fixing at the same time;
- then the frame (1A) is separated;
- The provided with the plastic sheath (2) conductor (1) are arranged on a ceramic plate (4) and due to the design of the parts, the current conductors (1) are arranged in the region of the measuring point in a section on the ceramic plate 4, wherein the one side of the ceramic plate (4) by means of the plastic sheath (2) is covered and on the opposite side of the ceramic plate (4) of the sensor (3) in flip-chip mounting and the components (5) of the switching power supply are arranged.

Description

The The invention relates to a manufacturing method for a current sensor of the microsystem technology technology.

Known For this purpose, WO 99/14605 A1 discloses a current sensor which is a complete unit a power monitoring system for galvanic separate current measurement is made in accordance with commercial IC fabrication and LOC packaging technology. A current path is Part of the conductive frame, with the help of a prefabricated adhesive strip Sensors are mounted to the die.

The JP 04364472 A makes it possible to measure a current value with great accuracy and improves the measuring accuracy of another closely adjacent position by introducing an electromagnetic converter with an electro-path conductor. By bonding the element and the conductor with resin, a unitary body is produced.

Furthermore, by the US patent, US 5 041 780 A It is known to provide a current conductor with opposing notches and to arrange magnetic flux sensors on both sides of the restricted section.

By the DE 41 41 386 A1 Furthermore, a Hall sensor is known. It consists of a Hall sensor of sufficient sensitivity integrated in a semiconductor chip, which has a magnetic field region of the conductor covering layer of ferromagnetic material. In particular, in the 2a and 2 B an embodiment is shown in which the semiconductor leadframe is formed such that a part thereof forms a conductor track, which acts as a metal loop for the Hall sensor.

• – Separieren von Ableitströmen,
• – Messen und Anzeigen der Leiterströme,
• – Setzen von vorgebbaren Schwellen, die bei Erreichen zur Vorwarnung oder zum Abschalten genutzt werden und dem Lastmanagement dienen können,
• – Ansteuern einer Datenschnittstelle,
• – Überprüfung von PE- und N-Leiter.

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 cost-effectively and a comprehensive signal processing is possible, ie additional functions can be added to the sensor, such as

• - Separation of leakage currents,
• - measuring and indicating the phase currents,
• - Setting predefinable thresholds that can be used when they are reached for pre-warning or for shutdown and that can be used for load management,
• - controlling a data interface,
• - Verification of PE and N conductors.

at the measurement of the electric current via the magnetic field measurement with z. B. Hall sensors o. Ä. There is a whole range of possible Aufbauvarianten, which is characterized by the usable measuring range, the achievable resolution and distinguish the achievable insulation resistance.

at The simplest version is the power conductor directly on the chip realized. Due to the small distance between the conductor and Sensor settles with this arrangement the highest Achieve accuracy. The maximum measuring current is in this case the current carrying capacity limited to metallization.

Higher currents can be measured when the conductor is not monolithically integrated. With external conductors can in principle very high currents be measured. The achievable resolution depends on the distance of the Sensor chips to the middle of the conductor starting from.

at Multi-pole sensors is the small distance between the conductors as important as the close distance of the conductors to the sensor chip. Also affected here a small distance the sensitivity to external fields.

It So there is a requirement that the Hall sensors close to the conductors are brought, d. H. a close spatial Connection of high voltages (several hundred volts) and high Stream (in case of short circuit some kA) of the grid side with the low voltages and currents of Silicon technology on the sensor side. Between these different ones Pages must be despite of the measuring technique required small distance a safe electrical isolation be given.

The Position of the conductor must be as accurate as possible over the whole temperature range and the entire operating time kept become. It can mechanical influences act as the electrodynamic forces from the parallel, narrow conductor guide and the high short-circuit currents, or thermal influences through the high conductor currents and the different thermal expansion coefficients of the used Materials.

task the invention is to find a construction and connection technique the small distance between the sensors and the conductors, and the conductors allowed each other while the electrical and mechanical strength over the entire service life guaranteed.

These The object is achieved by the Claim solved.

The invention is based on the figures explained.

It shows:

1 in conjunction with a surrounding frame 1A manufactured conductor 1 ,

2 those with a plastic sheath 2 provided conductor 1 after the frame 1A was separated.

3 a section through the with a plastic wrap 2 provided conductor 1 ,

4 the unit of the conductor 1 with plastic coating 2 , inserted in a ceramic plate 4 at which the sensor and the components of the switching power supply 5 are arranged.

The manufacturing process for a current sensor of the microsystem technology consists of the following steps:
The power conductors 1 , which have a cross-sectional reduction according to the allowable current carrying capacity at the measuring point and the smallest possible distance from each other, are combined with a circumferential frame 1A manufactured.

The power conductors 1 are then treated with a plastic wrap ( 2 ), which also serves as insulation and conductor fixing.

Subsequently, the frame becomes 1A separated.

The plastic wrap 2 provided conductor 1 are then on a ceramic plate 4 arranged, conditional on the design of the parts, the current conductor 1 in the area of the measuring point in a section on the ceramic plate 4 are arranged. One side of the ceramic plate 4 is by means of plastic wrap 2 covering and on the opposite side of the ceramic plate 4 become the sensor 3 in flip-chip assembly and the components 5 arranged the switching power supply.

The short distances between the excitation conductors to the Hall sensors and each other are due both to the special design of the excitation conductor as well as through the flip-chip mounting of the sensor 3 on the ceramic plate 4 reached.

The advantages are on the one hand in the high reliability of the dielectric strength, on the other hand in the simpler design possibility of the current conductor 1 , which in the composite to the sensor 3 introduced and therefore can be mounted inexpensively.

1

conductor

1A

frame

2

Plastic covering

3

sensor

4

ceramic plate

5

components of the switching power supply

Claims (1)

Manufacturing process for a current sensor of microsystems technology, comprising the steps of - the conductors ( 1 ), which have a cross-sectional reduction according to the permissible current carrying capacity at the measuring point and a minimum possible distance from each other, in conjunction with a peripheral frame ( 1A ) are manufactured; - the conductors ( 1 ) subsequently with a plastic sheath ( 2 ), wherein the plastic sheath serves as insulation and conductor fixing at the same time; - then the frame ( 1A ) is separated; - that with the plastic sheath ( 2 ) provided conductor ( 1 ) on a ceramic plate ( 4 ) and due to the design of the parts, the current conductors ( 1 ) in the area of the measuring point in a section on the ceramic plate 4 be arranged, wherein the one side of the ceramic plate ( 4 ) by means of the plastic covering ( 2 ) and on the opposite side of the ceramic plate ( 4 ) the sensor ( 3 ) in flip-chip mounting and the components ( 5 ) of the switching power supply can be arranged.