DE102019207383A1 - Interferometer device and method for manufacturing an interferometer device - Google Patents

Abstract

The present invention provides an interferometer device (10) comprising an interferometer unit (1) with a base substrate (2), a Fabry-Perot unit (FPI), and with a detector device (3), and a housing (G) which has a base plate ( BP) and a cover structure (4), the cover structure (4) being arranged on the base plate (BP) and enclosing a second cavity (K2) between the cover structure (4) and the base plate (BP), the base plate (BP) or the lid structure (4) comprises an opening (5) which is surrounded by side walls (5a) which extend perpendicular to a surface of the base plate (BP) or the lid structure (4); and wherein the interferometer unit (1) is arranged in the second cavity (K2) and in a direction of incidence of light (L) through the opening (5), so that the interferometer unit (1) with the Fabry-Perot unit (FPI) of the opening ( 5) is facing.

Description

The present invention relates to an interferometer device and a method for producing an interferometer device.

State of the art

Miniaturized spectrometers with Fabry-Perot interferometers (FPI) can be manufactured as a compact component and comprise a housing with an optical window, whereby a filter can usually be fixed on an inside with an adhesive. A negative pressure or even a vacuum can prevail inside the housing and a defined atmosphere can be developed so that gas attenuation occurs as little as possible during operation and the mirror spacing in the FPI can be changed quickly (tuning via the wavelengths of the light to be transmitted or filtered) to achieve short measurement times. In the case of negative pressure, however, a tensile force can be triggered on the adhesive connection and the robustness of the spectrometer can be reduced as a result.

In the WO 17057372 a detector structure for a miniaturized spectrometer with a Fabry-Perot interferometer is described, wherein a housing comprises an optical window (light transmission unit) and this can be provided with a band-pass filter coating and the window can be fixed on an inside of a metal cover by means of an adhesive .

Disclosure of the invention

The present invention provides an interferometer device according to claim 1 and a method for manufacturing an interferometer device according to claim 13.

Preferred further developments are the subject of the subclaims.

Advantages of the invention

The idea on which the present invention is based consists in specifying an interferometer device which, by means of fewer components, enables a small-scale component, in particular a filter element, with a low overall height and a detector device shielded from stray light and environmental influences. An incident light can be filtered and / or the angle of incidence can be restricted through a robust optical window.

According to the invention, the interferometer device comprises an interferometer unit with a base substrate which comprises an electrical conductor connection, with a Fabry-Perot unit which is arranged on the base substrate and forms a first cavity over the base substrate and is connected to the electrical conductor connection, and with a detector device which is arranged on the base substrate and is arranged in the first cavity between the base substrate and the interferometer unit and is connected to the electrical conductor connection; a housing which comprises a base plate and a cover structure, wherein the cover structure is arranged on the base plate and encloses a second cavity between the cover structure and the base plate, the base plate or the cover structure comprising an opening which is surrounded by side walls that extend to a surface of the The base plate or the cover structure extend vertically; and wherein the interferometer unit is arranged in the second cavity and in a direction of incidence of light through the opening, so that the interferometer unit with the Fabry-Perot unit faces the opening.

The base substrate can advantageously be shaped as a wiring substrate.

The first cavity below the Fabry-Perot unit can be shielded from outside light from the lateral sides and only allow the light transmitted into the first cavity by the interferometer unit, which can act as a filter for the outside light.

With the interferometer device according to the invention, the most cost-effective, yet powerful spectrometer (interferometer device) with the smallest possible number of components and a minimum number of simple / inexpensive manufacturing steps and the smallest possible size can be achieved, which is still achieved by a reduced or completely suppressed incidence of unfiltered scattered light, in particular from the lateral sides, on the detector. Conventional structures according to the prior art either require a large number of (expensive) components or (expensive) process steps or require large structural volumes or can allow for scattered light. The interferometer device can be produced as a small-scale, compact (package) detector arrangement with few components. Furthermore, a mechanically robust and largely hermetic sealing of the cavities can be achieved via a cover structure and a window element for closing an optical opening.

For a spectrometer, it is generally advantageous if the cone of incidence of the incident light can be restricted, which can lead to a higher resolution since obliquely incident rays can be shielded. In this way, unwanted reflections can also be reduced or avoided which could fall past the interferometer unit onto the detector.

According to a preferred embodiment of the interferometer device, it comprises at least one filter device which spans the opening inside or outside the housing.

According to a preferred embodiment of the interferometer device, the filter device comprises a spectral filter for incident radiation and / or an angle-selective element.

According to a preferred embodiment of the interferometer device, the opening comprises a round or circular cross section when viewed from a direction of incidence of light.

According to a preferred embodiment of the interferometer device, the opening forms a cylinder with the side walls, which cylinder extends perpendicularly away from the base plate or from the cover structure.

According to a preferred embodiment of the interferometer device, the base substrate is placed on contact pins which are fastened in the base plate or the cover structure.

According to a preferred embodiment of the interferometer device, at least one of the contact pins is electrically conductive or comprises an electrical conductor track.

According to a preferred embodiment of the interferometer device, the interferometer unit comprises an evaluation unit which is arranged on the base substrate, the detector device and the Fabry-Perot unit being arranged on the evaluation unit.

According to a preferred embodiment of the interferometer device, the detector device and the Fabry-Perot unit are connected to an electrical conductor connection of the base substrate and / or an evaluation unit and are electrically contacted.

According to a preferred embodiment of the interferometer device, the side walls comprise a light-absorbing coating on a side facing the opening.

According to a preferred embodiment of the interferometer device, the spectral filter has areas with different filter effects in the lateral direction and / or the angle-selective element has areas with different angle-selective effects in the lateral direction.

According to a preferred embodiment of the interferometer device, the detector device comprises several detector channels which are each aligned with the areas of different filter effects and can be read out separately.

According to a preferred embodiment of the interferometer device, the interferometer unit comprises a Fabry-Perot interferometer.

The Fabry-Perot interferometer can only transmit light of a certain wavelength for certain distances between the mirrors in the Fabry-Perot interferometer. By arranging the Fabry-Perot interferometer and / or the detector device or at least the Fabry-Perot interferometer directly on the base substrate, the overall height of the interferometer device can advantageously be reduced, since the electrical wiring can also be carried out via the base substrate, for example with a conductive one Glue and / or with bond wires.

According to a preferred embodiment of the interferometer device, the detector device and / or the interferometer unit are connected to the electrical conductor connection with a contact wire.

According to a preferred embodiment of the interferometer device, the cover structure comprises lateral side walls and a metal.

According to the invention, in the method for producing an interferometer device, a base substrate is provided which comprises at least one electrical conductor connection; arranging a detector device on the base substrate; arranging a Fabry-Perot unit on the base substrate such that a first cavity is formed over the base substrate and the detector device is located in the first cavity between the base substrate and the Fabry-Perot unit, the base substrate, the detector device and the Fabry-Perot unit form an interferometer unit; providing a base plate and a cover structure and securing the cover structure on the base plate in such a way that a second cavity is enclosed between the cover structure and the base plate and both form a housing, the base plate or the cover structure comprising an opening which is surrounded by side walls which extend extend perpendicular to a surface of the base plate or the lid structure; and wherein the interferometer unit is arranged in the second cavity and in a direction of incidence of light through the opening, so that the interferometer unit with the Fabry-Perot unit faces the opening.

The method can also be used in conjunction with the interferometer device features mentioned and their advantages and vice versa.

According to a preferred embodiment of the method, the interferometer unit is fastened with the base substrate to contact pins which are fastened in the base plate or the cover structure.

According to a preferred embodiment of the method, a filter device is arranged inside or outside the housing on the opening, spanning it.

Further features and advantages of embodiments of the invention emerge from the following description with reference to the accompanying drawings.

Figure list

The present invention is explained in more detail below with reference to the exemplary embodiments specified in the schematic figures of the drawing.

• 1 eine schematische Seitenansicht einer Interferometereinrichtung gemäß eines Ausführungsbeispiels der vorliegenden Erfindung; und
• 2 eine Darstellung von Verfahrensschritten eines Verfahrens zum Herstellen einer Interferometereinrichtung gemäß eines Ausführungsbeispiels der vorliegenden Erfindung.

Show it:

• 1 a schematic side view of an interferometer device according to an embodiment of the present invention; and
• 2 a representation of method steps of a method for producing an interferometer device according to an embodiment of the present invention.

In the figures, the same reference symbols denote identical or functionally identical elements.

1 shows a schematic side view of an interferometer device according to an embodiment of the present invention.

The interferometer device 10 comprises an interferometer unit 1 with a base substrate 2 , which comprises an electrical conductor connection La, with a Fabry-Perot unit FPI, which is on the base substrate 2 is arranged and a first cavity K1 above the base substrate 2 forms and is connected to the electrical conductor connection La, and with a detector device 3 which are on the base substrate 2 is arranged and in the first cavity K1 between the base substrate 2 and the interferometer unit 1 is arranged and is connected to the electrical conductor connection La. The interferometer device also includes 10 a case G which has a bottom plate BP and a lid structure 4th comprises, wherein the lid structure 4th is arranged on the bottom plate BP and a second cavity K2 between lid structure 4th and bottom plate BP, wherein the bottom plate BP or the lid structure 4th an opening 5 includes which of side walls 5a is surrounded, which becomes a surface of the base plate BP or the cover structure 4th extend vertically; and wherein the interferometer unit 1 in the second cavity K2 and in a light incidence direction L through the opening 5 , is arranged approximately along an optical axis AA, so that the interferometer unit 1 with the Fabry-Perot unit FPI of the opening 5 is facing.

A filter device 6th can the opening 5 span inside or outside the housing, advantageously completely. The opening 5 can comprise a round or circular cross section in plan view from a direction of incidence of light L, but can also deviate therefrom. When the opening 5 is circular, this can with its side walls 5a form a cylinder extending from the bottom plate BP or from the lid structure 4th can extend away vertically. The opening with the side walls itself acts as an angle-limiting for incident rays, since light rays with large angles of incidence with respect to the normal, that is to say optical axis AA, strike the side wall instead of the FPI. On the side wall 5a a reflection can then be suppressed, for example by absorption. This prevents light beams from simultaneously striking the FPI with different angles of incidence, which could reduce a possible wavelength resolution of the FPI. If such distributions of light were centered at a certain angle off the axis AA, the entire spectrum could be shifted at the detector, thus creating a so-called offset error. These shifts can be reduced or even avoided through the opening with the side walls.

The side walls 5a can on one of the opening 5 facing side a light-absorbing coating 9 include.

The base substrate 2 can be placed on contact pins ST, for example at least two, which are in the base plate BP or the cover structure 4th (not shown) can be attached. At least one of the contact pins ST can be electrically conductive or comprise an electrical conductor track, whereby the base substrate and / or other components can be electrically contacted. The contact pins can, for example, be inserted into recesses in the base substrate and held or fixed with connection areas t1. The connection areas t1 can be electrically conductive and advantageously flexible in order to be able to adapt flush to the inserted contact pins. The contact pins ST can be guided through recesses in the base plate BP and held there with sealing elements ml, which can nestle flush against the contact pins ST and are advantageous can be opaque and electrically insulating. A tight housing G can be formed by the flush connection.

The filter device 6th can use a spectral filter 6a for an incident radiation and / or an angle-selective element 6b include.

If light rays from different angles of incidence hit the Fabry-Perot interferometer at the same time, this can reduce possible wavelength resolution. The angle-selective element can advantageously restrict the angle of incidence of the incident light. If the distribution of the angles of incidence is still centered by a certain angle relative to a normal on the mirror surface of the interferometer unit, this can lead to a shift in the entire spectrum generated by the interferometer unit, that is to say to a wavelength offset error. Through the angle-selective element 6b this effect can also be reduced or avoided.

The opening itself can also have an angle-selective effect, wherein the angle-selective element can support this or can be omitted.

The spectral filter 6a can also be on an inside or outside over the opening 5 be arranged or both and the angle-selective element 6b can be on an inside or outside over the opening 5 be arranged, for example different from one another or shaped as the same element, and both can be the opening 5 span, preferably completely. Alternatively, you can use the spectral filter 6a and the angle selective element 6b also vice versa at the opening 4th be arranged, both present or only one of the two. The spectral filter 6a and / or the angle-selective element 6b can with an adhesive KL, for example electrically non-conductive, in the lateral edge area around the opening 5 be attached around. Instead of the adhesive, the connection KL can comprise a solder connection, for example a metallic solder connection, which can have better long-term stability with regard to the hermeticity than adhesive connections.

The spectral filter 6a can serve that through the opening 5 to filter transmitted light with regard to different orders (harmonics). Thus the spectral filter can 6a be set up to only certain orders or wavelength ranges of the outside light AL into the interior of the first cavity K1 (and second cavity) to pass. With several openings 5 the corresponding spectral filters can be designed for different wavelengths.

The interferometer unit 1 can be an evaluation unit 7th include those on the base substrate 2 can be arranged, wherein the detector device 3 and the Fabry-Perot unit FPI on the evaluation unit 7th can be arranged.

The lid structure 4th can have lateral sidewalls 4a and comprise a metal, the side walls 4a can be attached to the base plate BP with a solder or weld connection KL.

The base substrate 2 may comprise a wiring substrate such as a printed circuit board (or LTCC). The electrical conductor connection La can advantageously comprise one or more conductor tracks, for example each as a metallization, and on the base substrate 2 be applied to its front and / or back and / or in the base substrate 2 be integrated (embedded). Direct electrical contact can be made from the conductor track to the detector device by means of a wire contact DB 3 and / or to the Fabry-Perot unit FPI and / or to the evaluation device 7th be made. Alternatively, the evaluation unit in the interferometer device could also be dispensed with and this could be connected externally (not shown).

The detector device 3 can include one or more detectors which can be arranged on top of one another or next to one another, for example those which can be sensitive in different wavelength ranges.

The Fabry-Perot unit can comprise at least two mirror devices SP1 and SP2, which can be aligned in parallel and their spacing can be variable. Depending on the distance between the mirror devices, a certain wavelength of the light which passes through the opening 5 incident and filtered through the spectral filter and advantageously selected through the opening and / or the angle-selective element, in the direction of the detector device 3 propagate.

The mirror devices SP1 and / or SP2 can each include a dielectric mirror with two high-index layers (for example made of silicon or a compound with silicon) and a low-index layer located in between (for example air or vacuum).

Depending on the setting (distance between the mirror devices, the distance and thus the transmitted wavelength being variable) of the Fabry-Perot unit, external light can only be transmitted into the first cavity at a specific wavelength. The Fabry-Perot interferometer can transmit several wavelengths of different orders (modes) at the same time.

Because unfiltered radiation mostly or completely from the first cavity K1 can be kept away, this can advantageously affect a signal-to-noise ratio at the detector device 3 impact.

It may still be possible that in the lid structure 4th or bottom plate BP multiple openings 5 can be present, each of which can be assigned its own interferometer units, whereby different spectra (wavelengths) can be measured simultaneously.

The interferometer device 10 can be designed as a module (with module housing) for a larger component, for example as a microelectromechanical spectrometer module.

Since both the detector device 3 as well as the interferometer unit 1 on the base substrate 2 can be applied, advantageously directly, an overall height can be reduced vertically above and below the base substrate. The interferometer device 10 can thus be implemented in a few steps (a few costly steps) and at reduced costs as a small-scale component which can be produced even with a reduced number of components. The interferometer device 10 , and / or in particular the interferometer unit 1 can be formed as a micromechanical component.

The spectral filter 6a can in the lateral direction areas with different filter effects and / or the angle-selective element 6b can have areas with different angle-selective effects in the lateral direction. Accordingly, the detector device 3 comprise (several) detector channels aligned or arranged relative to these areas of the spectral filter and / or the angle-selective element, which are each aligned according to the areas of different filter action and can be read out separately, for example by an evaluation device (not shown).

By folding the detector channels, various information about the spectral distribution of a sample can be obtained and conclusions can be drawn about other properties.

The interferometer device enables a high spectral resolution and a reduced signal-to-noise ratio to be achieved. Furthermore, the interferometer device can be distinguished by a low scatter of the mode of operation from module to module.

2 shows a representation of method steps of a method for producing an interferometer device according to an embodiment of the present invention.

In the method for producing an interferometer device, a base substrate is provided S1a which comprises at least one electrical conductor connection; arranging S1b a detector device on the base substrate; Arranging Sic a Fabry-Perot unit on the base substrate in such a way that a first cavity is formed over the base substrate and the detector device is located in the first cavity between the base substrate and the Fabry-Perot unit, the base substrate, the detector device and the Fabry-Perot unit form an interferometer unit; providing S2a a base plate, advantageously equipped with a filter device, and a cover structure, and securing S2b the cover structure on the base plate in such a way that a second cavity is enclosed between the cover structure and the base plate and both form a housing, the base plate or the cover structure including an opening which is surrounded by side walls which extend perpendicular to a surface of the bottom plate or the lid structure; and wherein the interferometer unit is arranged in the second cavity and in a direction of incidence of light through the opening, so that the interferometer unit with the Fabry-Perot unit faces the opening. Steps S1a to S1c can be used to form the interferometer unit 1 respectively. At the same time, steps S2a and S2b can be performed with the inclusion of the interferometer unit 1 done to the housing G around the interferometer unit 1 to shape around and overall the interferometer device 10 to shape.

Although the present invention has been fully described above on the basis of the preferred exemplary embodiment, it is not restricted thereto, but rather can be modified in many different ways.

QUOTES INCLUDED IN THE DESCRIPTION

This list of the documents listed by the applicant was 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.

Patent literature cited

• WO 17057372 [0003]

Claims (15)

Interferometer device (10) comprising - An interferometer unit (1) with a base substrate (2), which comprises an electrical conductor connection (La), with a Fabry-Perot unit (FPI) which is arranged on the base substrate (2) and a first cavity (K1) the base substrate (2) and is connected to the electrical conductor connection (La), and with a detector device (3) which is arranged on the base substrate (2) and in the first cavity (K1) between the base substrate (2) and the Interferometer unit (1) is arranged and connected to the electrical conductor connection (La); - A housing (G) which comprises a base plate (BP) and a cover structure (4), the cover structure (4) being arranged on the base plate (BP) and a second cavity (K2) between the cover structure (4) and the base plate (BP ), wherein the base plate (BP) or the lid structure (4) comprises an opening (5) which is surrounded by side walls (5a) which extend perpendicular to a surface of the base plate (BP) or the lid structure (4); and wherein the interferometer unit (1) is arranged in the second cavity (K2) and in a direction of incidence of light (L) through the opening (5), so that the interferometer unit (1) with the Fabry-Perot unit (FPI) of the opening ( 5) is facing. Interferometer device (10) according to Claim 1 which comprises at least one filter device (6) which spans the opening (5) inside or outside the housing. Interferometer device (10) according to Claim 1 or 2 , in which the filter device (6) comprises a spectral filter (6a) for incident radiation and / or an angle-selective element (6b). Interferometer device (10) according to one of the Claims 1 to 3 , in which the opening (5) comprises a round or circular cross-section in plan view from a direction of incidence of light (L). Interferometer device (10) according to Claim 4 , in which the opening (5) with the side walls (5a) forms a cylinder which extends perpendicularly away from the base plate (BP) or from the cover structure (4). Interferometer device (10) according to one of the Claims 1 to 4th , in which the base substrate (2) is placed on contact pins (ST) which are fastened in the base plate (BP) or the cover structure (4). Interferometer device (10) according to Claim 6 , in which at least one of the contact pins (ST) is electrically conductive or comprises an electrical conductor track. Interferometer device (10) according to one of the Claims 1 to 7th , in which the interferometer unit (1) comprises an evaluation unit (7) which is arranged on the base substrate (2), the detector device (3) and the Fabry-Perot unit (FPI) being arranged on the evaluation unit (7). Interferometer device (10) according to one of the Claims 1 to 8th , in which the detector device (3) and the Fabry-Perot unit (FPI) are connected and electrically contacted to an electrical conductor connection (La) of the base substrate (2) and / or an evaluation unit. Interferometer device (10) according to one of the Claims 1 to 9 , in which the side walls (5a) comprise a light-absorbing coating (9) on a side facing the opening (5). Interferometer device (10) according to one of the Claims 1 to 10 , as far as referenced Claim 3 , in which the spectral filter (6a) has areas with different filter effects in the lateral direction and / or the angle-selective element (6b) has areas with different angle-selective effects in the lateral direction. Interferometer device (10) according to Claim 11 , in which the detector device (3) comprises several detector channels (3a) which are each aligned with the areas of different filter effects and can be read out separately. A method for producing an interferometer device (10) comprising the steps: - providing (Sla) a base substrate (2) which comprises at least one electrical conductor connection (La); - Arranging (S1b) a detector device (3) on the base substrate (2); - Arranging (S1c) a Fabry-Perot unit (FPI) on the base substrate (2) such that a first cavity (K1) is formed above the base substrate (2) and the detector device (3) is located in the first cavity (K1 ) is located between the base substrate (2) and the Fabry-Perot unit (FPI), the base substrate (2), the detector device (3) and the Fabry-Perot unit (FPI) forming an interferometer unit (1); - Providing (S2a) a base plate (BP) and a cover structure (4) and fastening (S2b) the cover structure (4) on the base plate (BP) in such a way that a second cavity (K2) between the cover structure (4) and the base plate (BP ) is enclosed and both form a housing (G), wherein the base plate (BP) or the cover structure (4) comprises an opening (5) which is surrounded by side walls (5a) which extend to a surface of the base plate (BP) or the Cover structure (4) extend vertically; and wherein the interferometer unit (1) is arranged in the second cavity (K2) and in a direction of incidence of light (L) through the opening (5), so that the interferometer unit (1) with the Fabry-Perot unit (FPI) of the opening ( 5) is facing. Procedure according to Claim 13 , in which the interferometer unit (1) is fastened to the base substrate (2) on contact pins (6) which are fastened in the base plate (BP) or the cover structure (4). Procedure according to Claim 13 or 14th , in which a filter device (6) inside or outside the housing (G) on the opening (5), spanning this, is arranged.

Images