CN116699481A

CN116699481A - Steam unit with improved heater structure

Info

Publication number: CN116699481A
Application number: CN202310202276.7A
Authority: CN
Inventors: A·布伦奈斯; J·弗里德里希-莫勒
Original assignee: Robert Bosch GmbH
Current assignee: Robert Bosch GmbH
Priority date: 2022-03-03
Filing date: 2023-03-02
Publication date: 2023-09-05
Also published as: DE102022202178A1

Abstract

The invention relates to a steam unit (10) for a sensor device (100) for measuring larmor frequency, comprising a volume (11) filled with at least one chemical substance, which is introduced into a base section (12) in the form of a through-guide and is closed off from a first side (14) by a first glass section (15) and from a second side (16) by a second glass section (17), wherein the steam unit enables a more uniform heating of the volume (11) with reduced energy consumption, wherein it is proposed that at least one heater structure (20) is arranged on the first side (14) and/or the second side (16) of the base section (12), which at least partially encloses the volume (11) on the first side (14) and/or the second side (16) of the base section (12).

Description

Steam unit with improved heater structure

Technical Field

The present invention relates to a steam unit for a sensor device for measuring larmor frequency and a sensor device, in particular for measuring changes in larmor frequency.

Background

Ultra-precise timers or frequency generators are an important component of many application schemes, such as, for example, information delivery schemes and navigation systems. Furthermore, ultra-accurate time measurement is critical for accurate navigation of an autonomous vehicle.

The most important aids for navigation and positioning of automatically driven vehicles are satellite based navigation systems. In these systems, such as for example the GPS system, the exact position is determined by the difference in signal transmission times from the individual navigation satellites to the vehicle. Here, each satellite continuously transmits its position and the transmission time of its signal to the receiver. The receiver compares the arrival times of the signals and is able to perform accurate positioning by the propagation time differences of the arriving satellite signals and the satellite positions transmitted together. In order to perform a correct position determination (x, y and z directions) there must be signals of at least four satellites at the receiver. In particular, in urban areas with high-rise buildings, the reception of satellite signals may be limited by the buildings. This prevents autopilot based solely on satellite navigation. The robustness of satellite navigation can be improved by an accurate time reference at the receiver with which the absolute time of arrival of the satellite signal can be detected. Thus, the number of required satellite signals can be reduced and the recovery of lost satellite signals is facilitated by accurate time measurements. For example, a stability of about 5x10-12 time measurement is required in order to bridge a 10 minute signal disruption. Such accuracy cannot be achieved with the quartz-or silicon-MEMS oscillators available to date.

Devices are known, such as for example atomic clocks or laser gyroscopes in aerospace, by means of which such accurate time measurements can be made. However, such devices are expensive to manufacture and are therefore cost-intensive. Furthermore, high-precision rotation rate sensors based on the nuclear spin resonance effect in inert gas isotopes are known, by means of which ultra-precise time measurements can be achieved. Such rotation rate sensors do not have the drawbacks of atomic clocks or laser gyroscopes. The rotation rate sensor has a steam unit, which typically consists of a structured stack of glass-silicon-glass. Cavities are etched into the silicon layer, which cavities are filled with the desired gas mixture. In order to optically access the atoms of the gas, glass wafers are used, which are bonded to the upper and/or lower side of the silicon wafer.

When an alkali metal, such as rubidium, cesium, potassium, is used (which is preferably applied in cavities in such a steam unit), the steam unit must be heated so that the alkali metal is present in its vapor phase. For example, when rubidium is used in the cavity, an operating temperature in the range of 70-150 ℃ is typically required. To achieve such an operating temperature, a heater structure is typically applied to the outer side of the glass wafer of the vapor unit. Here, poor thermal conductivity of the glass is problematic. A high heating power is required in order to still reach the desired temperature of the steam unit in the range of 70-150 c. Furthermore, poor thermal conductivity results in an uneven temperature distribution over the cross-section of the steam unit.

US 2011/0147367A1 describes a steam unit with a transparent heating structure arranged directly above the pockets on a glass wafer.

A steam unit is also known from JP 2017-215226A5, wherein a heating element is arranged on the steam unit on the outer side in order to heat the cavity to the operating temperature.

Disclosure of Invention

The aim of the present invention is to provide a steam unit that enables a more uniform heating of cavities or chambers with reduced energy consumption.

This object is solved by the features specified in claim 1. Further advantageous embodiments of the invention are described in the dependent claims.

According to one aspect of the present invention, a steam unit for a sensor device for measuring larmor frequency is provided. The steam unit has a volume or chamber filled with at least one chemical substance, which is introduced into the substrate in the form of a through-guide. The chamber or volume is closed from the first side by the first glass section and from the second side by the second glass section.

According to the invention, at least one heater structure is arranged on the substrate section on the first side and/or the second side of the substrate. The at least one heater structure at least partially encloses the volume.

In particular, the heater structure can at least partially surround the volume space on the circumferential side or be arranged adjacent to the volume space.

The steam unit can preferably be configured as an alkaline steam unit for a quantum sensor device. Here, the steam unit can be used in the fields of magnetometers, atomic clocks and gyroscopes.

The base section can preferably be made of silicon. Silicon is a good thermal conductor by virtue of a thermal conductivity of approximately 150W/m.k, which is in particular approximately two orders of magnitude higher with respect to the glass of the glass section. Thus, the desired operating temperature can be achieved with much less heating power. Furthermore, due to the good thermal conductivity of silicon, a more uniform temperature distribution occurs around the chamber. Furthermore, the glass closing the chamber on both sides in the silicon layer is responsible for good insulation.

According to one embodiment, the volume space comprises a measurement chamber and a reservoir chamber, which are fluidically connected to each other.

According to one advantageous embodiment, at least one heater structure for heating the measuring chamber and at least one heater structure for heating the storage chamber are provided. By this measure, each chamber can be individually heated, whereby particularly accurate temperature control can be achieved.

Alternatively, at least one heater structure for heating the measuring chamber and the reservoir chamber is provided. In this case, the heating means, in particular in the form of a conductor loop, can at least partially enclose or surround the two chambers. Such co-heating by the heating structure can be arranged on one or both sides of the base section.

The heating structure can be arranged not only on the first side of the base section and/or on the second side, so that the chamber can be heated selectively on one or both sides.

For alkaline steam units, this two-part arrangement of chambers connected to each other by connecting channels has proved advantageous. The reason for this is that the alkali metal (cesium, potassium, rubidium) is present as a solid at room temperature and in a (cold) steam unit at a pressure of typically a few mbar to a few hundred mbar and is deposited on the surfaces of the chamber. The residues of such deposits act as interference during operation, since the necessary transmission of the laser radiation for reading out the data of the respective sensor device is disturbed. Thus, the reservoir chamber is maintained at a lower temperature than the measurement chamber.

The temperature difference between the chambers causes the alkali vapors to condense, preferably in the reservoir chamber, and not deposit on the walls of the measurement chamber. The transmission of the detection laser through the measurement chamber can thereby be prevented from being disturbed. Furthermore, the spin coherence time of the base atoms can be extended and the measurement principle designed to be more robust.

The surfaces on both sides of the base section can be particularly advantageously configured for bonding of the glass section if the heating structure is arranged at least partially within at least one groove structure of the base section, which groove structure is introduced into the base section from the first side and/or the second side. The flat or planar closure of the two sides of the base section enables in particular a technically simple and reliable bonding.

According to a further alternative embodiment, the at least one heater structure arranged on the base section is electrically insulated by an insulating layer. Preferably, the at least one heater structure covered by the insulating layer is arranged inside the connection layer between the base section and the first glass section and/or between the base section and the second glass section. By this measure the introduction of additional trenches or trench structures can be dispensed with.

If the first glass section and/or the second glass section has at least one recess, it is particularly easy to connect the heater structure to a heating device or an external control device in terms of technology. The at least one heater structure opens into at least two coupling plates, which are advantageously formed in the recess of the first glass section and/or in the recess of the second glass section. The respective coupling plates can be connected by brazing.

According to another embodiment, the at least one heater structure is configured as an inductively couplable receiver coil. The receiver coil is preferably designed to receive the induced currents and/or eddy currents from at least one transmission coil arranged on the circumferential side and/or on the end side. Whereby the direct connection of the heater structure via the coupling plate can be dispensed with. Accordingly, the provision of a structured glass section with recesses can be dispensed with. By means of the energy transmission by means of induction, energy can be transmitted to the heater structure using a transmission coil arranged externally.

According to another aspect of the invention, a sensor device for measuring larmor frequency, in particular a variation of larmor frequency, is provided. The sensor device has at least one steam unit according to the invention. At least one heating means is provided for generating heat energy by means of at least one heater structure of the steam unit. At least one excitation laser is used for optically pumping at least one chemical substance in the volume space of the vapor unit. Furthermore, the sensor device has a first electromagnet for applying a static magnetic field to a volume space of the steam unit and a second electromagnet oriented perpendicular to the first electromagnet for applying an alternating magnetic field to the volume space.

Furthermore, the sensor device has an infrared laser, the radiation of which passes through the measuring chamber of the vapor unit and is directed at a detector in order to ascertain an intensity that is dependent on the larmor frequency.

The heating device can have a controller coupled to at least one heater structure of the steam unit. The control unit can be coupled to at least one heater structure in a current-conducting or inductive manner, whereby the heater structure can be actuated directly or indirectly by the control unit of the heating device.

In particular, the controller can load a preset or variable current directly to the heater structure in order to obtain the heating effect. Alternatively, the controller can operate the transmitting coil with an alternating voltage, which induces a current into the heater structure configured as the receiving coil, so that a heating action can be achieved by the heater structure. According to one advantageous embodiment, the heating device therefore has at least one transmitting coil arranged on the steam unit on the circumferential side and/or on the end side, which transmitting coil is inductively coupled to at least one heating structure in the form of a receiving coil.

According to another aspect of the invention, a method for manufacturing a steam unit according to the invention is provided. The base wafer is provided in one step. A plurality of through guides for constructing a chamber are introduced into the base wafer. These chambers are closed off by transparent wafers or glass wafers in a later manufacturing process in order to form a tightly closed volume. These chambers can be formed in particular by deep-grooving as one-piece chambers or as multipart chambers with connecting strips, for example measuring chambers and storage chambers.

In a further step, a heater structure is applied to the first side and/or the second side of the base wafer, said heater structure at least partially surrounding the through-guide.

A first glass wafer is positioned on a first side of the base wafer and a second glass wafer is positioned on a second side of the base wafer by bonding. Thereby, the chamber is hermetically closed by the first glass wafer and the second glass wafer. The chamber can be filled with one or more chemicals prior to closing the chamber.

Then, the first glass wafer, the base wafer having the heating structure, and the second glass wafer bonded to each other are separated into a first glass section, a base section, and a second glass section, which respectively constitute a vapor unit.

According to one embodiment, a plurality of trench structures can be introduced into the first side and/or the second side of the base wafer. The trench structure can be introduced into the base wafer by deep trench opening or by a separate manufacturing step in parallel with the shaping of the chamber. The trench structure is then coated with a conductive coating or filled with a conductive material. The electrically conductive coating or filling of the channel structure acts as a heater structure and can be directly or indirectly manipulated for generating heating power. The heater structure thus configured can be configured as a connector for direct electrical connection by the controller or as a closed conductor loop or coil acting as a receiving coil.

According to an alternative embodiment, a plurality of electrically conductive heater structures is arranged on the first side and/or the second side of the base wafer. The arranged heater structure is electrically insulated by an insulating layer. In this embodiment, the introduction of the trench structure can be dispensed with. Furthermore, the first side and the second side of the base wafer are coated with a copper layer, which serves as a connection layer for eutectic bonding of the first glass wafer and/or the second glass wafer.

According to a further aspect of the invention, a method for measuring larmor frequency is provided, in particular with a sensor device according to the invention, wherein the sensor device has at least one steam unit according to the invention. The at least one steam unit is heated by a heating structure arranged in or at the base section. In a further step, at least one chemical substance in the volume of the vapor unit is optically pumped by at least one excitation laser. In parallel with this, a static magnetic field is applied to the volume by means of a first electromagnet and an alternating magnetic field is applied to the volume by means of a second electromagnet oriented perpendicular to the first electromagnet. Thereafter, the measuring chamber of the vapor cell is irradiated by an infrared laser, wherein the radiation emitted from the vapor cell is directed at a detector in order to ascertain the intensity of the radiation generated by the infrared laser as a function of the larmor frequency.

Drawings

Various embodiments of the present invention are explained in detail below with the aid of the accompanying drawings. Wherein:

figure 1 shows a schematic view of a sensor device according to an embodiment of the invention,

fig. 2a-2f show process steps for illustrating a method according to the invention, for manufacturing a steam unit according to a first embodiment,

fig. 3a-3c show process steps for illustrating a method according to the invention, for manufacturing a steam unit according to a second embodiment,

figure 4 shows a top view of a steam unit according to a third embodiment,

figure 5 shows a top view of a steam unit according to a fourth embodiment,

figures 6a and b show cross-sectional views of a steam unit according to a fifth and a sixth embodiment,

fig. 7a, b show top views of a steam unit according to a fifth and a sixth embodiment, and

fig. 8a, b show sectional views for explaining a method according to the invention for producing a steam unit according to a seventh embodiment.

Detailed Description

In fig. 1 a schematic view of a sensor device 100 according to an embodiment of the invention is shown. The sensor device 100 is illustratively configured as a so-called NMR rotation rate sensor system and is used to measure larmor frequency.

The sensor device 100 has a steam unit 10. The volume space 11 of the steam unit 10, which is marked in fig. 2f, is illustratively filled with Rb and Xe as chemicals.

The excitation laser 110, which is configured as a polarized pump laser, causes polarization of the Rb electron spins in the vapor cell 10, which also results in polarization of the Xe nuclear spins by electron nuclear spin coupling between Rb and Xe.

In addition, a static magnetic field B for applying a static magnetic field B to the steam unit 10 is provided ₀ Is provided for the first electromagnet 111. A magnetic field B generated by the first electromagnet 111 ₀ Causing a limited larmor frequency of Xe atoms. As an alternative to Xe, other atoms having a nuclear spin that does not go to zero, such as e.g. He or Kr, can also be used in the vapor unit 10. The following uses B ₀ To represent a static magnetic field.

The second electromagnet 112 is used to generate a static magnetic field B perpendicular to the rotation axis or perpendicular to the static magnetic field B ₀ AC magnetic field B of (2) _x . AC magnetic field B _x Corresponds to the larmor precession frequency and causes coherent precession of all nuclear spins. The coherent precession of the Xe nuclear spin in turn affects the precession of the Rb electron spin. To convert this modification of the Rb electron spin due to Xe coherent precession into a readable signal, a polarized laser beam is generated by an infrared laser 113 tuned to the Rb wavelength. The infrared laser 113 radiates through the steam unit 10. The corresponding laser beam generated by the infrared laser 113 can hit the detector 114 after transmission through the steam unit 10 and be evaluated.

The polarization of the laser beam of the infrared laser 113 is periodically rotated at the larmor frequency due to the faraday effect caused by the varying Rb spin precession of the gas. A polarization filter 115 situated in front of the detector 114, which is illustratively made as a photodiode, enables a weakening of the laser beam generated by the infrared laser 113 as a function of this polarization, so that intensity fluctuations modulated at the larmor frequency can be observed on the detector 114.

Rotation of the sensor device 100 causes a shift in the larmor frequency proportional to the rotation rate of the sensor device 100, which can be measured at the detector 114. The heating means 120 are provided for adjusting the constant temperature of said steam unit 10 to about 115 ℃. The heating device 120 has a heater structure 20, which is electrically connected to a controller 121. In particular, the controller 121 is coupled to the heater structure 20 via a coupling plate 21. In particular, the controller 121 can directly load the heater structure 20 with a preset or variable current in order to obtain a heating effect.

By the resulting warming of the steam unit 10, rb in the steam unit 10 is in the form of steam and has a constant Rb steam pressure. The steam unit atmosphere or the chemical substances required for the sensor device 100 can also be realized by a substance mixture of, for example, xe129, xe131 and Ar.

Combinations with other inert gas isotopes, such as He, ne or Kr, and other buffer gases, such as nitrogen, are also possible. Common to both embodiments is a vapor unit 10 as an atom of the sensing element, which is filled with basic atoms and a defined composition of isotopically pure inert gas and buffer gas. According to a design, the chemical substance can be enclosed in the steam unit 10 by overpressure.

Furthermore, the sensor device 100 can be protected by a housing 116. Preferably, the housing 116 is configured in the form of a magnetic shield.

In fig. 2a-2f process steps are shown for illustrating a method according to the invention for manufacturing a steam unit 10 according to the first embodiment. In this case, a 1-chamber steam unit 10 with a heater structure 20 is produced in an exemplary manner in a base section 12 made of silicon. Here, fig. 2a, 2b and 2c show sectional views along the line L in fig. 2d, 2e and 2 f.

The steam unit 10 is manufactured by means of a wafer-based manufacturing method, but for the sake of simplicity only one cut-out is shown, which cut-out shows the base section 12 as part of the base wafer. Thus, fig. 2d, 2e and 2f show detailed views onto a wafer of the steam unit chip or steam unit 10 during different process steps.

In a first step shown in fig. 2a and 2d, the through-holes 41 are introduced by means of a deep etching process into a base wafer 40, which is embodied as a silicon wafer, which later forms the chamber 13 with the volume space 11. Furthermore, annular trench structures 42 of smaller depth are trench-opened into the base wafer 40 around the deep trench or through-hole 41.

Such trench structures 42 with smaller depths can be realized either by an additional process sequence consisting of photolithography, deep trench-opening, resist-Strip techniques (Lack-Strip).

Alternatively, the dependence of the vertical etch rate of the trench on the opening area is exploited. Since the chambers 13 typically have diameters of several hundred μm to several mm, the vertical etching rates are significantly higher here than in the case of smaller structured surfaces as they are for the additional trench structures 42. The width of these trench structures 42 is typically in the range of a few μm up to a few tens of μm.

In a further step, shown in fig. 2b and 2e, the trench structure 42 is at least partially coated or filled with a metal 43. Such metal 43 in the trench structure 42 later constitutes the heater structure 20. As the metal, copper, aluminum, platinum, gold, or the like can be used, for example.

Fig. 2c and 2e show a step in which a first glass wafer is arranged on the first side 14 of the base wafer 40 and a second glass wafer is arranged on the second side 16 of the base wafer 40 and subsequently separated. A plurality of steam units 10 is thereby produced, which have a base section 12 with a first glass section 15 on a first side 14 and a second glass section 17 arranged on a second side 16. The first glass section 15 and the second glass section 17 define an opening 41 on both sides and thus form the chamber 13. Furthermore, in the embodiment shown, the first glass section 15 covers the heater structure 20 at least partially.

In particular, the second glass wafer, not shown, can be bonded on the underside or second side 16 of the base wafer 40. The opening 41 can now be filled with a liquid or a solid, which later occupies the volume space 11. Subsequently, a structured first glass wafer, not shown in detail, is bonded to the upper or first side 14 of the base wafer 40. The first glass wafer is structured in such a way that openings or recesses 45 are present in the first glass wafer at the later points of the coupling plate 21 for the heater arrangement 20. It is alternatively possible to fill the chamber 13 with gas during the bonding process. Different conventional bonding methods can be used for the bonding, such as anodic bonding, eutectic bonding, etc.

The method shown in fig. 2 can also be applied to a steam unit 10 having two or more chambers 13. Fig. 3a, 3b and 3c show the main process steps for a steam unit 10 with two chambers 18, 19, wherein the volume space 11 is divided into a measuring chamber 18 and a reservoir chamber 19, which are connected to one another in a fluid-conducting manner.

The two chambers 18, 19 likewise have a heater structure 20 introduced into the base section 12, wherein in the exemplary embodiment shown the common heater structure 20 completely encloses the measuring chamber 18 and the storage chamber 19. The measuring chamber 18 and the reservoir chamber 19 are connected to each other by a connecting channel 44. In particular, the measuring chamber 18 and the reservoir chamber 19 are filled with at least one chemical substance and are tightly closed by the glass sections 15, 17.

In order to produce a steam unit with two chambers 18, 19, in a first step the two chambers 18, 19 are produced in the base wafer 40 by means of a deep-trench process. In addition, trench structures 42 having a smaller depth are trenched or etched. The channel structure 42 later serves as the heater structure 20. In addition to the trench structures 42, structures 44 in the form of connection channels 44 are also introduced into the base wafer 40. In fig. 3a, the substrate wafer 40 is shown after the described material removal by ditching or etching.

Furthermore, in a further step shown in fig. 3b, the trench structures 42 that are trench-etched or trench-etched are at least partially coated or filled with metal and which later form the heater structures 20. The structure for constructing the connection channel 44 is not filled.

Furthermore, glass wafers 15, 17 are bonded to both sides 14, 16 of the base wafer 40, similarly to fig. 2. The chambers 18, 19 of the steam unit 10 are filled with a gas, liquid or solid before or during the final bonding step.

Subsequently, similar to fig. 2c or fig. 2f, the device is divided into a plurality of sections forming a plurality of steam units 10 having two chambers 18, 19, respectively. This last step is shown in fig. 3 c.

For a 2-chamber vapor unit 10, there are possible designs for heater structures 20 that heat both chambers 18, 19 simultaneously. An example of a combined heater structure 20 for both chambers 18, 19 is shown in fig. 3c and 4.

Fig. 4 shows a 2-chamber steam unit 10 with a combined heater structure 20 for the measurement chamber 18 and the reservoir chamber 19. Thus, the heater structure 20 comprises two chambers 18, 19 of the steam unit 10. Different numbers of coils, different thicknesses of the introduced conductors, different spacing with respect to the chambers 18, 19, etc. enable control of the temperature distribution and temperature difference between the reservoir chamber 19 and the measurement chamber 18. In particular, a lower temperature can be set in the reservoir chamber 19 relative to the measurement chamber 18.

As a result, the alkali vapor filled into the volume space 11 can first condense in the reservoir chamber 19 and does not deposit on the side walls of the measuring chamber 18.

Fig. 5 shows a top view of a steam unit 10 according to a fourth embodiment, wherein the steam unit 10 has two heater structures 20 which enable individual and independent heating of the measuring chamber 18 and the storage chamber 19.

Each of the heater structures 20 opens into a respective coupling plate 21, which can be accessed for making electrical contact by way of a recess 45 in the first glass section 15.

For all the heater structures 20 described so far, it is provided that they are in direct electrical contact with the heater structures 20 and are heated by means of the current fed through the coupling plate 21. For this purpose, a recess 45 or a perforation must be formed in the first glass section 15 in order to be able to contact the coupling plate 21. Pre-structuring of the first and/or second glass wafer may not be desirable.

Fig. 6a and 6b show an alternative inductively coupled heater structure 22, which acts as a receiving coil. Here, a cross-sectional view of the steam unit 10 according to the fifth and sixth embodiments is shown. The inductively-couplable heater structure 22 does not have any gussets 21 and therefore does not require any perforations in the glass sections 15, 17.

The heater structure 22 shown in the illustrated embodiment serves as an inductive heating device, which is fed with a corresponding current via an external transmitting coil 23. In particular, eddy currents can be induced in the heater structure 22 by the transmitting coil 23.

Fig. 6a shows a transmission coil 23, which is arranged externally or on the circumferential side around the steam unit 10 and is traversed by an alternating current. Fig. 6b shows an external alternating current transmission coil 23, which is positioned below the steam unit 10. Alternatively or additionally, the transmitting coil 23 can be arranged above the steam unit 10.

The corresponding groove structures 42 for producing the heater structure 22 configured as a receiver coil can be shaped in the form of circles, polygons or ovals.

The transmitting coil 23 can be located on a steam unit holder, not shown, or on a printed circuit board or PCB. For the purpose of illustrating the shape of the heater structure 22 configured as a receiving coil, a top view of the steam unit 10 according to the fifth and sixth embodiment is shown in fig. 7a and 7 b. Here, fig. 7a shows a 1-chamber steam unit 10, and fig. 7b shows a 2-chamber steam unit 10 with an inductively couplable heater structure 22.

For a 2-chamber steam unit 10, the control of the heating power (sideways) can be regulated by the different widths of the heater structure 22 surrounding the chambers 18, 19. Alternatively, the number of windings of the transmitting coil 23 can be varied locally in order to control the induced current intensity in the heater structure 22.

The heater structure 20 or passive metal structure or inductively couplable heater structure 22 that is machined into the base section 12 has been described in the previous embodiments. An advantage of this approach is a (closed) planar surface on the first side 14 and/or the second side 16, which can then be bonded. In fig. 8a and 8b, a cross-sectional view is shown for illustrating a method according to the invention for manufacturing a steam unit 10 according to a seventh embodiment.

In particular, an alternative possibility is described for applying the active or passive heater structures 20, 22 directly on the upper side of the base section 12 and subsequently using a eutectic bonding method. Thereby enabling the creation of the trench structure 42 to be omitted. The metal structure 43 is applied, for example, by means of a template or mask in combination with vapor deposition or by means of an adhesive method.

After the application of the metallic heater structures 20, 22, an insulating layer 24, such as for example SiO, is used ₂ Surrounding it.

Subsequently, a copper layer is applied as a connection layer 30 for eutectic bonding of the first glass wafer or first glass segment 15 and/or the second glass wafer or second glass segment 17.

The heater structure 20, 22 with the insulating layer 24 is encapsulated in the connection layer 30 after bonding. In the exemplary embodiment shown, a heater arrangement 22 in the form of a receiving coil is provided for the measuring chamber 18 and the storage chamber 19, respectively. The arrows illustrate the bonding direction caused by a bond, which is illustratively designed as a eutectic bond.

Claims

1. Steam unit (10) for a sensor device (100) for measuring larmor frequency, having a volume (11) filled with at least one chemical substance, which volume is introduced into a base section (12) in the form of a through-guide and is closed off from a first side (14) by a first glass section (15) and from a second side (16) by a second glass section (17), characterized in that at least one heater structure (20) is arranged on the base section (12) on the first side (14) and/or the second side (16) of the base section (12), which heater structure at least partially encloses the volume (11).

2. The steam unit according to claim 1, wherein the volume space (11) has a measuring chamber (18) and a reservoir chamber (19) which are fluidically connected to each other, wherein at least one heater structure (20) for heating the measuring chamber (18) and at least one heater structure (20) for heating the reservoir chamber (19) are provided; or alternatively

At least one heater structure (20) is provided for heating the measuring chamber (18) and the reservoir chamber (19).

3. The steam unit according to claim 1 or 2, wherein the heater structure (20) is arranged at least partially within at least one trench structure (42) of the base section (12), which trench structure is introduced into the base section (12) from the first side (14) and/or the second side (16).

4. The steam unit according to claim 1 or 2, wherein the at least one heater structure (20, 22) arranged on the base section (12) is electrically insulated by an insulating layer (24), wherein the at least one heater structure (20, 22) covered by the insulating layer (24) is arranged within a connection layer (30) between the base section (12) and the first glass section (15) and/or between the base section (12) and the second glass section (17).

5. The steam unit according to any one of claims 1 to 4, wherein the first glass section (15) and/or the second glass section (17) has at least one recess (45), wherein the at least one heater structure (20) opens into at least two coupling plates (21) which are configured in the recess (45) of the first glass section (15) and/or the recess (45) of the second glass section (17).

6. Steam unit according to any one of claims 1 to 4, wherein the at least one heater structure (22) is configured as an inductively couplable receiver coil, wherein the receiver coil is set up for receiving induced currents and/or eddy currents from at least one transmission coil (23) arranged on the circumferential side and/or on the end side.

7. Sensor device (100) for measuring larmor frequency, in particular a variation of larmor frequency, having:

the at least one steam unit (10) according to any one of the preceding claims;

at least one heating device (120) for generating thermal energy by means of at least one heater structure (20, 22) of the steam unit (10);

at least one excitation laser (110) for optically pumping at least one chemical substance in a volume (11) of the vapor unit (10);

for applying a static magnetic field (B) to the volume (11) of the steam unit (10) ₀ ) Is provided with a first electromagnet (111); and

a second electromagnet (112) oriented perpendicular to the first electromagnet (111) for loading the volume (11) with an alternating magnetic field (B _x ) The method comprises the steps of carrying out a first treatment on the surface of the And

an infrared laser (113) radiating through a measurement chamber (18) of the vapor unit (10) and being aligned with a detector (114) in order to ascertain an intensity dependent on the larmor frequency.

8. Sensor device according to claim 7, wherein the heating device (120) has at least one transmitting coil (23) arranged on the steam unit (10) on the circumferential side and/or on the end side, which transmitting coil is inductively coupled with at least one heater structure (22) configured as a receiving coil.

9. Method for manufacturing a steam unit (10) according to any one of claims 1 to 6, wherein:

providing a base wafer (40) and introducing a plurality of through guides (41) for constructing chambers (13, 18, 19) into the base wafer (40),

-applying a heater structure (20, 22) to the first side (14) and/or the second side (16) of the base wafer (40), the heater structure at least partially surrounding the through-going guide (41),

positioning a first glass wafer on a first side (14) of the base wafer (40) and a second glass wafer on a second side (16) of the base wafer (40) by bonding, wherein the chambers (13, 18, 19) are hermetically closed by the first and second glass wafers,

-separating the first glass wafer, the base wafer (40) with the heater structure (20, 22) and the second glass wafer bonded to each other into a first glass section (15), a base section (12) and a second glass section (17), which respectively constitute the steam unit (10).

10. Method according to claim 9, wherein a plurality of trench structures (42) are introduced into the first side (14) and/or the second side (16) of the base wafer (40), wherein the trench structures (42) are coated with a conductive coating (43) or filled with a conductive material (43),

or alternatively

Wherein a plurality of electrically conductive heater structures (20, 22) are arranged on the first side (14) and/or the second side (16) of the base wafer (40), wherein the arranged heater structures (20, 22) are electrically insulated by an insulating layer (23), and wherein the first side (14) and the second side (16) of the base wafer (40) are coated with a copper layer as a connection layer (30) for eutectic bonding of the first glass wafer and/or the second glass wafer.