DE102008034033B4 - Microelectronic sensor component - Google Patents

Abstract

Microelectronic sensor component comprising a carrier element with a ceramic base body (1) and at least one receiving surface (1.1 ... 1.10) suitable for attaching one or more layers, the base body (1) being provided with incisions made perpendicular to the plane of the receiving surfaces, so that the receiving surface (1.1 ... 1.10) are on individual sub-bodies, the incisions having different distances so that existing thermal bridges between the sub-bodies have different thermal capacities, with a platinum resistance layer being arranged on the receiving surfaces (1.1 ... 1.10) above which has a passivation layer and a cover layer with a defined spectral sensitivity is applied over it.

Description

The invention relates to a microelectronic sensor component having a carrier element with a ceramic base body and at least one suitable for attaching one or more layers receiving surface, wherein the base body is provided with perpendicular to the plane of the receiving surface incisions, so that the receiving surfaces are located on individual partial bodies.

The invention is suitable for detecting and transmitting different physical quantities. For example, thermal flows, gas or liquid temperatures, radiations, thermal conductivities and numerous other variables can be detected. The components can also be used for dynamic radiation transmitters, for example in pulse mode.

In order to achieve high dynamics, the carrier systems for such components must have the lowest possible heat capacity.

In the prior art support systems for such applications, which consist of silicon or ceramic, are well known.

According to DE 20 2007 014 477 U1 a printed circuit board is preferably described for gas sensors.

Furthermore, in DE 43 06 268 A1 described an arrangement in which sensors are mounted, among other things cantilevered to electrical connection wires.

These arrangements are not suitable for dynamic microsystem applications.

The invention has for its object to provide a microelectronic sensor device, which allows high dynamics and is inexpensive to produce.

According to the invention the object is achieved with an arrangement which contains the features specified in claims 1 or 2.

Advantageous embodiments are specified in the subclaims.

In the arrangement according to the invention, sensor elements or radiation-emitting components with defined properties are arranged on very small defined surfaces, which are connected via a defined thermal bridge with at least one further element and wherein all sensor elements have defined heat capacities.

It is also possible that the sensor elements are electrically heated by power.

The sensor element preferably consists of a ceramic body, on which meander-shaped resistance structures made of platinum are mounted.

• – Die Anordnung kann mit einfachen, in der Mikrosystemtechnik üblichen Herstellungsverfahren kostengünstig gefertigt werden.
• – Die Anordnung gestattet es, Sensorbauelemente herzustellen, die eine hohe Dynamik gewährleisten.
• – Es können in einfacher Weise Segmente mit verschiedenen Wärmekapazitäten realisiert werden, so dass auch Anordnungen realisiert werden können, deren Messgenauigkeit im Verlaufe ihrer Lebensdauer überwacht werden kann.
• – Die Aufnahmeflächen können mit unterschiedlichen Funktionselementen ausgerüstet werden, die sowohl als Sender als auch als Sensoren verwendet werden können.
• – Es können Widerstandselemente mit definiertem Widerstandswerten auf einer sehr kleinen definierten Fläche angeordnet werden, die wiederum über eine definierte thermische Brücke mit einem zweiten und dritten Widerstandselement verbunden ist, wobei alle drei über definierte Wärmekapazitäten verfügen.

The invention is characterized by a number of advantages. These include in particular:

• - The arrangement can be manufactured inexpensively with simple, customary in microsystem technology manufacturing process.
• - The arrangement makes it possible to produce sensor components that ensure high dynamics.
• It can be realized in a simple manner segments with different heat capacities, so that arrangements can be realized, the accuracy of which can be monitored in the course of their life.
• - The recording surfaces can be equipped with different functional elements that can be used both as transmitter and as sensors.
• Resistance elements with defined resistance values can be arranged on a very small defined area, which in turn is connected via a defined thermal bridge to a second and third resistance element, wherein all three have defined heat capacities.

The invention will be explained in more detail below with reference to an embodiment.

In the accompanying drawings show:

1a 3 is a perspective view of a basic body with two sections made perpendicular to the plane of the receiving surfaces, wherein a section was taken from above,

1b a perspective view of a base body in which a section was made perpendicular to the plane of the receiving surfaces and a section parallel to the plane of the receiving surface,

1c 3 is a perspective view of a basic body with two sections made perpendicular to the plane of the receiving surfaces, a section being taken from below,

2 a longitudinal section through the in 1 represented basic body and

3 the too 2 appropriate top view.

The in 1 illustrated basic body 1 consists of a ceramic made of Al ₂ O ₃ . It is divided into segments with two cuts. The cut was done so that segments of different dimensions arise. In the example shown, the main body contains ten segments. Thus, sensitive elements can be arranged on surfaces which have a different size and wherein the segments have different heat capacities.

At the in 1a In the embodiment shown, the cuts were made from above, ie running through the plane of the receiving surface.

In 1b is a basic body 1 shown in which a section perpendicular to the plane of the receiving surfaces and a second section was performed parallel to the plane of the receiving surface.

At the in 1c In the embodiment shown, one of the two cuts was made from below.

2 shows a longitudinal section through the in 1 illustrated basic body 1 , wherein on the receiving surfaces layers were applied. These layers consist here of a meander-shaped resistance layer 2 made of platinum, a passivation layer 3 and a cover layer 4 ,

In 3 is that too 2 associated with the top view. Functional elements S1 to S10 are arranged on the ten segments. The functional elements are connected via connecting lines with an evaluation unit, not shown. In the example shown, the connection cables 5.11 and 5.12 for the functional element S1 shown. The remaining functional elements can be connected in the same way with an evaluation unit.

The functional elements can be equipped for different tasks depending on the application.

Here are four examples of the sensor application:

1. flow sensor

In this application, three functional elements are used, which are mounted on segments of different dimensions. In this case, a functional element is designed as a heater, a second functional element measures the energy flow direction-dependent and the third functional element is a sensor with which the ambient temperature is detected.

2. Radiation receiver

Here are located on the bearing surfaces of the support elements resistance layers 2 , in the case of the invention, a platinum resistance layer provided with passivation layers 3 to be protected. On the passivation layers 3 are topcoats 4 applied, which can detect radiation energy. The cover layers have different radiation sensitivities ε. With a first functional element, which has the radiation sensitivities ε ₁ , predominantly infrared light can be detected, while a second functional element is provided with a cover layer which has a radiation sensitivity different from ε ₁ and predominantly measures UV radiations. Furthermore, it is possible to emit different radiation with this arrangement, so that the arrangement can be used as a dynamic energy radiator.

3. Thermal conductivity detector

If the sensor is placed in a flow-protected housing, it can be used as a thermal conductivity sensor. For this purpose, an arrangement with three functional elements can be used by one element S1 as a heater / measuring resistor and another element S2 is also designed as a heater / measuring resistor, but operated at a different overtemperature.

This also tertiary gas mixtures can be detected because the thermal conductivity is temperature-dependent, or in gas / air mixtures in particular H ₂ in air above 150 ° C, the so-called heat of reaction and the hot air conductivity superimposed with this signal.

4. Gas sensor

With an arrangement in which a semiconductor gas sensor is heated to a certain temperature above ambient temperature, the temperature is detected with a temperature-sensitive heater, and simultaneously detected signals of the semiconductor gas sensor and signals of a thermal conductivity sensor, hydrogen mixtures can be detected with high accuracy and stability. If an arrangement is used which uses the support structure described here, the arrangement can be realized on a single chip, wherein, instead of a resistance element, an interdigital structure for a MOS gas sensor is realized.

LIST OF REFERENCE NUMBERS

1

body

2

resistance layer

3

passivation

4

topcoat

5.11, 5.12

connecting cables

S1 ... S10

individual sensors

1.1 ... 1.10

receiving surfaces

Claims (4)

Microelectronic sensor component comprising a carrier element with a ceramic base body ( 1 ) and at least one receiving surface suitable for attaching one or more layers ( 1.1 ... 1.10 ), where the basic body ( 1 ) is provided with perpendicular to the plane of the receiving surfaces mounted incisions, so that the receiving surface ( 1.1 ... 1.10 ) are on individual sub-bodies, wherein the incisions have different distances, so that between the sub-bodies existing thermal bridges have different heat capacities, wherein on the receiving surfaces ( 1.1 ... 1.10 ) a platinum resistance layer is disposed, above which a passivation layer is located and above a cover layer with a defined spectral sensitivity is attached. Microelectronic sensor component comprising a carrier element with a ceramic base body ( 1 ) and at least one receiving surface suitable for attaching one or more layers ( 1.1 ... 1.10 ), where the basic body ( 1 ) is provided with perpendicular to the plane of the receiving surface mounted incisions, so that the receiving surfaces ( 1.1 ... 1.10 ) are on individual sub-bodies, wherein the incisions have different distances, so that between the sub-bodies existing thermal bridges have different heat capacities, wherein on the receiving surfaces different arrangements for detection and / or transmitting functions are arranged, of which on a receiving surface ( 1.1 ) a heater, on another receiving surface ( 1.2 ) a radiation meter and on a third receiving surface ( 1.3 ) a temperature sensor are arranged. Microelectronic sensor component according to claim 1 or 2, characterized in that the incisions are arranged in two mutually perpendicular directions. Microelectronic sensor component according to claim 1 or 2, characterized in that the basic body ( 1 ) Has incisions which are both perpendicular and parallel to the plane of the receiving surfaces ( 1.1 ... 1.10 ).

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