EP4673776A2 - Package and method for producing a package - Google Patents

Abstract

The present invention relates to a package comprising a substrate (11) and a MEMS chip (1), the MEMS chip (1) being attached to the substrate (11). A further aspect of the invention relates to a method for producing a package.

Description

Description

Package and method for producing a package

The present application relates to a package and a method for producing a package.

A package is a housing and protective structure that contains and encloses a MEMS chip. The package plays a crucial role in the functionality, reliability, and longevity of the MEMS chip.

In a package, the MEMS chip should be protected from damage during installation in a device as well as from environmental influences.

The object of the present invention is to provide an advantageous package that is suitable, for example, for an optical MEMS system.

This object is achieved by the subject matter of the independent claims. Advantageous embodiments are the subject matter of the dependent claims.

A package is proposed that includes a substrate and a MEMS chip mounted on the substrate.

The MEMS chip may have at least one electrical component. The electrical component may be arranged on one side of the MEMS chip. The MEMS chip may be attached to the substrate in such a way that the side of the MEMS chip on which the electrical component is arranged faces the substrate. The MEMS chip may have a plurality of electrical components, all of which are arranged on the side of the MEMS chip facing the substrate.

The MEMS chip may include at least one electrical component arranged on a side of the MEMS chip facing away from the substrate. The MEMS chip may include multiple electrical components, all arranged on the side of the MEMS chip facing away from the substrate.

The MEMS chip may comprise at least two electrical components, wherein one electrical component is arranged on a side of the MEMS chip facing away from the substrate, and wherein one electrical component is arranged on a side of the MEMS chip facing towards the substrate.

The electrical component(s) may be drive elements configured to move a movable element of the MEMS chip. The drive elements may comprise piezoelectric actuators.

The arrangement of the electrical component on the side of the MEMS chip facing the substrate can be achieved, for example, by attaching the MEMS chip to the substrate using a flip-chip design. Attaching the MEMS chip to the substrate using a flip-chip design can make it possible to arrange the substrate's electrical contacts directly beneath the MEMS chip, so that an area of the substrate to the side of the MEMS chip does not have to be used for contacting the chip. This allows the package to be made smaller overall. Furthermore, flip-chip attachment can make it possible to use a MEMS chip made from a single silicon layer. A second silicon layer, which serves, for example, as a spacer between a movable element of the MEMS chip and the substrate, can be omitted. Accordingly, the height of the MEMS chip can be reduced, and the use of an etching process, in particular a DRIE etching process, in the manufacture of the MEMS chip can be omitted. This simplifies the manufacturing process and also makes it more cost-effective.

The substrate can be a ceramic substrate. The substrate can comprise aluminum oxide or layers consisting of aluminum oxide. The substrate can be manufactured using an additive manufacturing process, such as a 3D printing process. A ceramic substrate can have a higher thermal conductivity than a circuit board, so that heat can be quickly conducted away from the MEMS chip through the ceramic substrate.

The MEMS chip can be a MEMS mirror. The MEMS chip can have or be a MEMS-based acoustic component, for example a microphone, ultrasonic sensor or loudspeaker. The MEMS chip can have or be a MEMS-based component for measuring physical parameters, for example a pressure sensor, temperature sensor, light sensor, radiation sensor, magnetic field sensor. The MEMS chip can have or be an inertial sensor, for example an acceleration sensor, vibration sensor, tilt sensor or gyroscope. The MEMS chip can have or be an optical component, for example an image sensor, a mirror element, a scanner element, an interferometer or a microsized laser. communication terminal scanning system. The MEMS chip can also have or be a component for measuring chemical parameters, for example a hydrogen sensor, a gas sensor, a biosensor, a glucose sensor or a lab-on-chip sensor.

The MEMS chip can have one or more movable elements, where one of the movable elements can in particular be a movable mirror element. The MEMS chip can also contain electrical lines, electrical feedthroughs (TSV trans-silicon vias) and active and passive elements. These elements can be integrated directly into the MEMS chip. For example, overvoltage protection elements can be integrated directly into the MEMS. This can be a PN diode, for example.

The electrical component can have a drive element that is designed to move the movable element of the MEMS chip. The electrical component can be applied as an additional layer on the MEMS chip. The electrical component can have a piezoelectric actuator. The electrical components can also include NTCs, capacitors or coils. The MEMS chip can have a plurality of electrical components, wherein at least one of the electrical components can be arranged on the side of the MEMS chip facing the substrate. Several of the electrical components can be arranged on the side facing the substrate. All of the electrical components of the MEMS chip can be arranged on the side facing the substrate. The MEMS chip can have electrical contacts on the side facing the substrate, which are connected to electrical contacts of the substrate. The electrical contacts of the MEMS chip and the substrate can each have solder pads, wherein the electrical contacts of the MEMS chip and the substrate are each connected to one another via a solder ball.

The electrical contacts of the MEMS chip can be arranged on the underside of the MEMS chip facing the substrate and on a side surface of the MEMS chip that is perpendicular to the substrate. Accordingly, the electrical contacts of the MEMS chip can be L-shaped in cross-section. By arranging the contacts on the underside facing the substrate and the side surface perpendicular to it, the electrical contact can be formed over a particularly large area and reliable contact can be ensured.

The electrical contacts of the MEMS chip can be connected to the electrical contacts of the substrate via solder balls. The MEMS chip can have a movable element, in particular a movable mirror element, wherein the height of the solder balls is selected such that the movable element does not strike the substrate during movement. Even if the movable element is deflected by its maximum deflection from its rest position, the solder ball arranged between the substrate and the MEMS chip can prevent the movable element from coming into contact with the substrate. The solder balls can thus assume the function of a spacer. Additional spacers or a second silicon layer, which creates a distance between the movable element and the substrate guaranteed, can be dispensed with. By using sufficiently high solder balls it can be made possible to use a MEMS chip which has a single silicon layer. The solder balls can be designed in such a way that a cavity is formed between the movable element in its rest position and an upper side of the substrate arranged below the movable element, so that a distance between the movable element in its rest position and the upper side of the substrate is at least 300 pm. The cavity can have a base area of 1 mm ² . The base area is parallel to the substrate.

The substrate may have a via, via which one of the electrical contacts of the substrate is connected to an external electrical contact arranged on the side of the substrate facing away from the MEMS chip. Alternatively or additionally, the substrate may have a conductor track, via which one of the contacts of the substrate is contacted to an external electrical contact of the substrate, which contact is arranged on an upper side of the substrate facing the MEMS chip or on a side surface of the substrate that is perpendicular to the upper side.

Both the via and the conductor track can be hermetically or quasi-hermetically sealed electrical lines.

The electrical contacts of the MEMS chip can be partially enclosed by a slot in the MEMS chip. The slot can completely penetrate the material of the MEMS chip. The slot can, for example, connect the electrical contacts to enclose three sides, with a fourth side of the electrical contacts not enclosed by the slot.

The slot can ensure that the MEMS chip is designed as a spring-loaded suspension in the area of the electrical contacts. The MEMS chip can have a higher deformability in the area in which the slots partially enclose the electrical contacts than in an active area which has the electrical component. If a prestress is now exerted on the MEMS chip, for example due to different thermal expansion coefficients of the substrate and the MEMS chip, the spring-loaded suspension formed by the slots can ensure that the MEMS chip is only deformed in the area of the electrical contacts and that the active area which has the electrical component and which can also have the movable element, for example, is not deformed at all or is deformed only to a small extent.

The MEMS chip can be electrically connected to the substrate via bond wires. Bonding via bond wires represents an alternative to contacting using a flip-chip design.

The MEMS chip can have a single layer comprising silicon. The MEMS chip can also have at least one layer comprising glass, aluminum oxide, diamond, steel, silicon nitride, silicon carbide, polysilicon, aluminum nitride, or boron nitride. The MEMS chip can, in particular, be manufactured from a wafer consisting of a single silicon layer. Accordingly, the use of an SOI wafer can be dispensed with. A stress relief layer can be arranged between the substrate and the MEMS chip. The stress relief layer can be designed to relieve mechanical stresses that can arise due to different thermal expansion coefficients of the substrate and the MEMS chip. The stress relief layer can be arranged either between a top side of the substrate and an electrical contact formed on the substrate or between a bottom side of the MEMS chip and an electrical contact of the MEMS chip. Furthermore, it is possible for a first stress relief layer to be arranged on the substrate and a second stress relief layer to be arranged on the MEMS chip.

The substrate can have a spacer on the side facing the MEMS chip, against which the MEMS chip rests. The spacer can be used to set a distance between an upper side of the substrate and an underside of the MEMS chip. The spacer can be high enough that a movable element, in particular a movable mirror element, of the MEMS chip does not come into contact with the upper side of the substrate even when it is deflected to the maximum from its rest position. By using the spacer, a package can be constructed in which there is no need for a recess in the upper side of the substrate or an opening extending through the substrate. The spacer can be designed such that a cavity is formed between the movable element in its rest position and an upper side of the substrate arranged below the movable element, so that a distance between the movable element in its rest position and the upper side of the substrate is at least 300 pm. The cavity can have a base area of 1 ^mm2 . The substrate may have a recess on the side facing the MEMS chip, above which a movable element of the MEMS chip is arranged. Alternatively, the substrate may have an opening extending through the substrate, above which the movable element is arranged. The recess or opening may be configured such that the movable element does not strike the substrate even at its maximum deflection.

The package may further comprise an encapsulation which, together with the substrate, encapsulates a cavity in which the MEMS chip is arranged. The encapsulation may comprise a frame surrounding the MEMS chip. The encapsulation may comprise a window that closes an opening in the frame or an opening in the substrate.

The cavity can be hermetically sealed by encapsulation. Accordingly, the MEMS chip within the cavity can be protected from moisture, such as water vapor or other environmental gases. Accordingly, the MEMS chip can be protected from corrosion, oxidation, and aging of optical and electroactive components. Hermetic encapsulation can also prevent moisture from forming inside the cavity due to condensation as a result of temperature fluctuations.

The MEMS chip may contain sensitive moving elements, particularly movable mirror elements. The encapsulation may provide mechanical protection to protect the moving elements during assembly and manufacturing. The encapsulation can be designed so that the cavity remains optically accessible. For example, part of the encapsulation or the entire encapsulation can be transparent to light rays in the visible spectrum.

The encapsulation can be designed to be application-specific. For example, the encapsulation can be designed to withstand various media.

The encapsulation can have a window that is optically transparent. The window can, for example, have glass or be made of glass. Alternatively, the window can have a transparent plastic or be made of a transparent plastic. The window can have an anti-reflective coating. The anti-reflective coating can ensure that a laser beam striking the window is not reflected or is reflected only to a very small extent.

The window can form an angle of between 5° and 20° with the surface of a movable element of the MEMS chip when the movable element is at rest. The window, which is arranged at an angle to the movable element, ensures that even a reflected laser beam does not interfere with the signal laser beam, since the signal laser beam propagates in a different direction than the beam reflected at the window.

The encapsulation may have two windows that are optically transparent. The two windows may be arranged obliquely to each other and, for example, form an angle between 10 ° and 170 °. Alternatively, the Both windows must be parallel and opposite each other.

Part or all of the encapsulation can be manufactured using an additive manufacturing process, particularly a 3D printing process. Compared to traditional ceramic manufacturing processes, additive manufacturing allows for increased design flexibility. For example, the substrate can be designed with a bend. An angled area of the substrate can be manufactured using an additive process to serve as the package's mounting base.

Accordingly, the individual elements of the package can be aligned at virtually any angle to each other and to a circuit board. The additive manufacturing process can also make it possible to produce the substrate and the encapsulation in a single production step, eliminating the need for adhesive bonds between the individual elements. The electrical structures of the substrate, in particular conductor tracks, vias, and electrical contacts of the substrate, could also be manufactured using the additive manufacturing process.

The electrical component may include a piezoelectric actuator or be a piezoelectric actuator. The actuator may be configured to move the movable element of the MEMS chip. For example, the actuator may be configured to cause a movable mirror element to oscillate.

The MEMS chip can in particular comprise a MEMS micromirror with a movable mirror element. The movable The mirror element may comprise a reflective layer arranged on the side of the MEMS chip facing the substrate. Alternatively or additionally, the movable mirror element may comprise a reflective layer arranged on the side of the MEMS chip facing away from the substrate.

The movable mirror element can have a mechanical reinforcement structure on a side facing away from the reflective layer. The reinforcement structure can have bars. The mechanical reinforcement structure can be formed by thickened portions of the movable mirror element. The thickened portions can be bar-shaped. The bars can be straight or curved.

Due to the mechanical reinforcement structure, the mirror element can be designed in such a way that it experiences little or no deformation even in the case of vibrations with a high vibration amplitude.

The MEMS chip, especially the moving elements, can contain integrated light-sensitive or sound-pressure-sensitive electronic components that can measure the deflection of the mirror element. It is also possible that magnetic or electrostatically charged components

(triboelectric effect) on the moving elements serve to generate an electromagnetic signal that can be measured with the help of sensors on the substrate.

An AS IC, a laser module and/or control electronics for controlling the laser module can be arranged on the substrate. These elements can be arranged on a top side facing the MEMS chip or on a bottom side facing away from the MEMS chip. These elements can be arranged either in an encapsulated cavity or outside the encapsulated cavity.

Furthermore, light-sensitive or sound-pressure-sensitive components can be arranged on the substrate. These can measure the deflection and position of the movable elements of the MEMS chip. It is also possible for the deflection of the movable elements of the MEMS chip to be measured by inductive or capacitive sensors on the substrate. These measure the electromagnetic field generated by magnetic or electrostatically charged elements on at least one movable element of the mirror.

The laser module can be configured to emit a laser beam. The laser module can have one or more laser diodes. The AS IC can be configured to control the MEMS chip. For this purpose, the AS IC can send control signals to drive elements of the MEMS chip.

At least one optical component, such as a mirror or a lens, may be arranged on the substrate. Each of the optical components may be arranged on the top or bottom side of the substrate. The optical components may be arranged inside or outside the encapsulated cavity.

At least one sensor can be arranged on the substrate. The sensor can be arranged inside or outside the encapsulated region. Multiple sensors can be arranged on the substrate. A microscopic fluid channel can be formed in the substrate. The microscopic fluid channel can be manufactured using an additive manufacturing process. Such a channel can be formed without great effort using an additive manufacturing process.

The package can be configured to pump a liquid, such as water or glycol, through the microscopic fluid channel to adjust the temperature of the MEMS chip and/or other components of the package. The other components can be, for example, a laser module. The MEMS chip and the laser module can be heated during operation, so cooling through the microscopic fluid channel can be useful.

The substrate can have a fastening foot which is designed to fasten the substrate to a printed circuit board, wherein the fastening foot can be arranged at an angle to the MEMS chip such that the package can be fastened to the printed circuit board such that the MEMS chip is arranged at an angle to the printed circuit board. The fastening foot can in particular be manufactured using an additive manufacturing process which can make it possible to arrange elements at almost any angle to one another. The addition of the fastening foot can make it possible to arrange the MEMS chip and/or a window at an angle to a light source, for example a laser module.

The substrate may have a bend. If the substrate has a bend, the MEMS chip may be arranged at an angle to the light source. A bend in the substrate may be formed, in particular, by an additive manufacturing process. In one embodiment, the package may include a device for aligning the package, which is configured to move, for example, tilt, the substrate relative to a holder. The device may include a flexible membrane, a microfluidic pump, and/or a piezoelectric actuator.

At least one actuator, in particular a piezoelectric actuator, can be arranged on the substrate and is designed to move the MEMS chip. The actuator arranged on the substrate can be additional or alternative to a drive element, for example a piezoelectric actuator, on the MEMS chip. The actuator on the substrate can be designed to set the movable element of the MEMS chip into an oscillatory motion, for example a Lissajous oscillation.

The MEMS chip may include a movable element. The package may include a device for determining a deflection of the movable element.

The device for determining a deflection of the movable element can comprise a light-sensitive element. The package can be designed such that an amount of light striking the light-sensitive element depends on the deflection of the movable element and that the deflection of the movable element is determined by evaluating a measurement signal received by the light-sensitive element. The light-sensitive element can be designed to generate a sensor signal as a result of a light beam striking the light-sensitive element, wherein the light-sensitive element is provided with an evaluation unit which is designed to determine a deflection of the movable element from the sensor signal measured by the light-sensitive element. The device can also have several of the light-sensitive elements described above.

The light-sensitive element can be arranged on the movable element. The light-sensitive element can be arranged such that a light beam deflected by the movable element strikes the light-sensitive element. The movable element can be at least partially transparent to light of a wavelength range, wherein the light-sensitive element is arranged on the substrate such that a light beam passing through the movable element strikes the light-sensitive element.

The package can have a light source for emitting a measuring laser beam, which is arranged such that the measuring laser beam strikes the movable element, wherein a deflection of the movable element is determined by measuring the deflection of the measuring laser beam by the movable element. The measuring laser beam can be incident at a different angle than the optical beam path. The deflection of the measuring laser beam can be measured via a light-sensitive element.

The light-sensitive element can be arranged in the areas of the package into which the movable element reflects the measuring laser beam during its various deflections.

The measuring laser beam can enter the package either from the top or the bottom. The device for determining the deflection of the movable element can comprise a sound pressure sensitive sensor located either on the MEMS chip or on the substrate.

The movable element may comprise an electronic component that charges through movement in air, wherein the device for determining the deflection of the movable element comprises an inductive or capacitive sensor that is designed to measure an electric field generated by the electronic component that charges through movement in air. The inductive or capacitive sensor may be arranged on the substrate or on the MEMS chip, or integrated into the MEMS chip.

A further aspect relates to a method for producing a plurality of packages. These packages can be the packages described above. Any structural or functional feature disclosed in connection with the package can accordingly also be implemented for the packages produced using the method.

The procedure comprises the following steps:

- Attaching a plurality of MEMS chips to a wafer, each MEMS chip having an electrical component on one side, and the MEMS chips being attached to the wafer in such a way that the side on which the electrical component is arranged faces the wafer,

- Singling the wafer, and

- Encapsulation of the packages by an encapsulation, which together with the substrate encapsulates a cavity in which the MEMS chip is arranged , this step taking place after the wafer has been singulated .

Accordingly, the MEMS chips are encapsulated into a package only after the wafer has been singulated. This process is also referred to as die-level packaging. Encapsulating the MEMS chips before the wafer has been singulated is referred to as wafer-level packaging.

Wafer-level packaging has the following disadvantages when using large optical MEMS chips. Wafer-level packaging also encapsulates defective MEMS chips and only sorts them out after singulation. Especially with large, complex MEMS chips, this can result in significant scrap costs, which can be avoided by encapsulating them after singulation.

During wafer-level packaging, the wafer may experience warpage, which reduces the quality of the manufactured packages. If encapsulation is performed at the die level, this distortion can be avoided.

Installation and handling are more complex with wafer-level packaging than with die-level packaging.

With die-level packaging, the MEMS chips can be arranged closer together on the wafer before singulation, since no additional space needs to be reserved for a housing structure.

Preferred embodiments are described below with reference to the figures. Figures 1 to 32 show schematic representations of the

Packages or parts of the package .

Figures 33 to 38 show photographs showing the package at various stages of its manufacture and after installation in a printed circuit board .

Figure 39 shows schematically a process for producing the package.

Figures 40 to 49 show various embodiments of the package.

Figure 1 shows a first exemplary embodiment of a MEMS chip 1. The MEMS chip is a microelectromechanical mirror. Figure 1 shows a perspective view of the underside of the MEMS chip.

The MEMS chip 1 comprises a mirror element 2, which is connected to a drive element 3 via two first spring elements 4. The drive element 3 is connected to a rigid region 5 of the MEMS chip 1 via two second spring elements 6. The rigid region 5, the drive element 3, the mirror element 2 and the spring elements 4, 6 are formed integrally from a common substrate, for example from silicon, in particular by etching the common substrate. Furthermore, electrical contacts of the MEMS chip are arranged on the rigid 5.

A reflective layer 21 , for example made of a metal , is applied to the mirror element 2 , which is designed for at least partial reflection of light in the visible spectral range . The mirror element 2 has a mirror suspension 22 which is directly connected to the first spring elements 4. The mirror suspension 22 is particularly designed to reduce deformation of the surface of the mirror element 2 during operation of the microelectromechanical mirror 1.

The drive element 3 has an elongated, elliptical ring shape with a short axis SA and a long axis LA perpendicular thereto. The drive element 3 completely surrounds the mirror element 2 in its main extension plane in the rest position. The first spring elements 4 are arranged on opposite sides of the mirror element 2 along the long axis LA, while the second spring elements 6 are arranged on opposite sides of the drive element 3 along the short axis SA. The first spring elements 4 and the second spring elements 6 are designed as torsion spring elements.

A piezoelectric layer is applied to the substrate of the drive element 3. The piezoelectric layer is made, for example, of PZT, AIN, or BFO-BT and is arranged between two metallic electrode layers. At least one of the electrode layers is segmented and has first control regions 31a, 31b and second control regions 32a, 32b that are electrically insulated from one another.

By applying an alternating voltage to the first control regions 31a, 31b during operation of the MEMS chip 1, a temporally periodic mechanical stress is generated in the piezoelectric layer, which resonantly excites a first oscillation mode of the mirror element 2. The first oscillation mode has a torsional oscillation of the Mirror element 2 about a first axis of rotation which corresponds to the long axis LA.

By applying an alternating voltage to the second control regions 32a, 32b during operation of the microelectromechanical mirror 1, a temporally periodic mechanical stress is generated in the piezoelectric layer, which resonantly excites a second oscillation mode of the mirror element 2. The second oscillation mode exhibits a rotational oscillation of the mirror element 2 about a second rotational axis, which corresponds to the short axis SA.

The oscillation frequencies of the rotational vibrations of mirror element 2 about the short axis SA and the long axis LA correspond to the resonance frequencies of the two vibration modes and are different from one another. A laser beam reflected by mirror element 2 during operation thus generates, for example, a Lissajous pattern on a projection surface. The frequency ratio between the two oscillation frequencies is preferably a rational ratio.

The MEMS chip can have a width and a length that are each greater than 5 mm.

Figures 2 and 3 show schematically the production of the

MEMS chips 1 made from an SOI wafer (SOI = Silicon-on-Insulator).

The SOI wafer has a first silicon layer 7 from which the movable structures of the MEMS chip are manufactured. Furthermore, the SOI wafer has a second silicon layer 8, which is separated from the first silicon layer 7 by an etch stop layer 9. The second silicon layer 8 can be used, among other things, for handling the MEMS chip 1 during production. The second silicon layer 8 has a greater thickness than the first silicon layer 7. The etch stop layer 9 can be a silicon oxide layer.

Electrical contacts 10 of the MEMS chip 1 are arranged on the side of the first silicon layer 7 which faces away from the second silicon layer 8. The electrical contacts 10 can be solder pads. The finished MEMS chip 1 can be contacted with a substrate 11 via the electrical contacts 10. The side of the MEMS chip 1 on which the electrical contacts 10 are arranged is referred to below as the underside. The drive elements 3 and a reflective layer of the MEMS chip 1 can also be arranged on the underside.

The MEMS chip 1 is manufactured by an etching process in which parts of the second silicon layer 8, the etching stop layer 9 and the first silicon layer 7 are removed, so that free-standing movable structures are formed from the first silicon layer 7. In this way, for example, the movable mirror element 2, the spring elements 4, 6 and regions on which the drive elements 3 are arranged on the first silicon layer 7 can be formed. Figure 2 shows the MEMS chip 1 before the etching process and Figure 3 shows the MEMS chip 1 after the etching process has been carried out.

The drive elements 3 , which are piezoelectric

Actuators can act as another layer on the MEMS chip 1 is applied. The drive elements 3 are applied to the movable element 2.

The drive elements 3 can be applied to the side of the movable element 2 that faces away from the electrical contacts 10 if the MEMS chip is designed for contacting by means of bonding wires (Figure 4). The drive elements 3 can be applied to the side of the movable element 2 on which the electrical contacts 10 are also arranged if the MEMS chip is designed for contacting by means of flip chip bonding (Figure 5).

Figure 4 shows the attachment of the MEMS chip 1 shown in Figure 3 to the substrate 11. The MEMS chip 1 is attached to the substrate 11 by means of an adhesive layer 12. The adhesive layer 12 connects one side of the second silicon layer 8 to the substrate, which side faces away from the first silicon layer 7. The electrical contacts 10 of the MEMS chip 1 are arranged on a side of the MEMS chip 1 that faces away from the substrate 11. The drive elements are arranged on the side of the MEMS chip 1 that faces towards the substrate 11.

The substrate 11 has internal and external electrical contacts 13, 14. The electrical contacts of the substrate 11 that are electrically connected to the contacts 10 of the MEMS chip 1 are referred to as internal electrical contacts 13. The internal electrical contacts 13 of the substrate 11 can be encapsulated together with the MEMS chip 1 in a cavity. The internal electrical contacts 13 of the substrate 11 are arranged on a top side of the substrate 11 that faces the MEMS chip 1. The internal electrical contacts 13 of the substrate 11 may have solder pads.

The external electrical contacts 14 of the substrate 11 are configured for contacting a printed circuit board or an external power supply. The external contacts 14 can be connected to the internal contacts 13 via conductive tracks and/or vias. The external electrical contacts 14 of the substrate 11 can have solder pads.

In the embodiment shown in Figure 4, the inner electrical contacts 13 are arranged laterally of the MEMS chip 1. The electrical contacts 10 of the MEMS chip 1 are connected to the inner electrical contacts 13 of the substrate 11 via bonding wires 15.

A frame is also arranged on the substrate. This frame is part of an encapsulation that encapsulates the MEMS chip. Since an area to the side of the MEMS chip must be kept free for the substrate's electrical contacts, the frame cannot be placed directly next to the MEMS chip.

In the embodiment shown in Figure 4, the second silicon layer 8 creates a cavity beneath the movable element 2 of the MEMS chip 1. The cavity ensures that the movable element 2 can move without restriction and, in particular, does not collide with the substrate 11.

Figure 5 shows an alternative for attaching the MEMS chip 1 shown in Figure 3 to the substrate 11. The MEMS chip 1 is mounted in Figure 5 in flip chip design on the substrate 11. Accordingly, the MEMS chip 1 is attached to the substrate 11 in such a way that the underside of the MEMS chip 1, on which the electrical contacts 10 and the drive elements 3 are arranged, faces the substrate 11.

In the embodiment shown in Figure 5, the inner electrical contacts 13 of the substrate 11 are arranged on the upper side of the substrate 11 facing the MEMS chip 1 directly below the electrical contacts 10 of the MEMS chip 1.

The electrical contacts 10 of the MEMS chip 1 and the internal electrical contacts 13 of the substrate 11 are connected via solder balls 16. The solder balls 16 may contain tin or be made of tin.

The area to the side of the MEMS chip 1 is not required for the internal electrical contacts 13 of the substrate 11. Accordingly, a frame 17 can be arranged directly next to the MEMS chip, as shown in Figure 6.

The substrate 11 shown in Figure 5 further has an opening 18 which extends through the substrate 11. The MEMS chip 1 is arranged on the substrate 11 such that the movable element 2 is located above the opening 18. The substrate 11 shown in Figure 6 has a recess 19 in its upper side which is arranged below the movable element 2 of the MEMS chip 1. The recess 19 does not extend through the entire thickness of the substrate 11.

Both the opening 18 in the substrate 11 and the recess

19 in the top side of the substrate 11 ensures that there is sufficient space for the movable element 2 to move is provided. The movable element 2 is prevented from coming into mechanical contact with the substrate 11. If the MEMS chip 1 is attached to the substrate 11 in flip-chip construction, the function previously assumed by the second silicon layer 8 of creating the cavity under the movable element 2 can be realized by the opening 18 or the recess 19 in the substrate 11.

In further embodiments, this function can be performed by a spacer 20 arranged between the substrate 11 and the MEMS chip 1 or by high solder balls 16 (compare Figures 15 and 16).

The attachment of the MEMS chip 1 in flip chip design to the substrate 11 shown in Figures 5 and 6 has, in addition to the aforementioned advantages of reduced space requirements next to the MEMS chip 1 and the possibility of omitting the second silicon layer 8, the following advantages compared to the attachment using bonding wires 15 shown in Figure 4:

The flip-chip design allows for a reduction in the length of the electrical paths compared to contacting with bond wires 15, thus reducing delays in signal transmission. This improves the performance of the MEMS chip in terms of speed and signal integrity.

The flip-chip design allows heat to be dissipated more effectively from the MEMS chip 1 to the substrate 11 than with contacting with bond wires 15. This improves the thermal management of the package, and overheating can be avoided. The flip-chip design allows electrical contacts 13 of the substrate 11 to be arranged closer together than is possible with bond wires 15. This allows for an increase in I/O capacity.

Figure 7 shows a MEMS chip 1 mounted on a substrate 11 according to a further embodiment. The MEMS chip 1 shown in Figure 7 is also mounted on the substrate 11 using flip-chip technology.

The MEMS chip 1 according to the further exemplary embodiment is made from a single silicon layer 7. The MEMS chip 1 therefore has no etch stop layer 9 and no second silicon layer 8. Accordingly, the MEMS chip 1 has a significantly lower height than the MEMS chip 1 shown in Figure 5.

Since the second silicon layer 8 is not required to create a cavity beneath the movable element 2 during flip-chip attachment, it can be omitted. Thus, the MEMS chip 1 does not need to be manufactured from an SOI wafer. Instead, the MEMS chip can be manufactured from a wafer having a single silicon layer 7. Accordingly, the height of the component can be reduced. Furthermore, costs can be saved because the wafer consisting of a single silicon layer is cheaper than an SOI wafer.

In addition, the manufacturing process can be simplified since the etching process of the second silicon layer 8 can be omitted. Since the second silicon layer 8 is usually thick, the etching process the second silicon layer 8 is a DRIE process (DRIE = Deep Reactive Ion Etching). A DRIE process is very complex and expensive because it requires special tools, e.g. inductively coupled plasma etchers. In addition, a DRIE process is slow and thus leads to a long process time. A DRIE process is also prone to errors and thus leads to a not insignificant amount of scrap. Overall, the manufacturing process can be significantly improved by eliminating the DRIE process.

In the embodiment shown in Figure 7, the opening 18, which extends through the substrate 11, is arranged below the movable element 2 of the MEMS chip 1. Alternatively, a recess 19 could be formed in the upper side of the substrate 11.

Figure 8 shows a detailed view of the MEMS chip 1 attached to the substrate 11, as shown in Figure 6. The substrate 11 is a ceramic substrate. It can comprise aluminum oxide or consist of aluminum oxide. The substrate 11 can have a multilayer structure in which conductor tracks are integrated into the substrate 11. The substrate 11 can be manufactured using an additive manufacturing process.

The inner electrical contact 13 of the substrate 11 is formed in the form of a solder pad on the upper side of the substrate 11 facing the MEMS chip 1. A metallization 23, also referred to as "under bump metallization," is arranged on the upper side of the contact 13 facing the MEMS chip 1. The internal electrical contact 13 of the substrate 11 is connected to the external electrical contact 14 on the underside of the substrate 11 via a via 24 extending through the substrate 11. The external electrical contact 14 on the underside of the substrate 11 is designed to connect the substrate 11 to a printed circuit board or an external power supply.

A stress relief layer 25 is arranged between the inner electrical contact 13 of the substrate 11 and the upper side of the substrate. The stress relief layer comprises a polymer or another dielectric material, for example silicon nitride. The stress relief layer 25 is designed to relieve mechanical stresses between the substrate 11 and the MEMS chip 1, which are connected via the solder joint.

On the underside of the MEMS chip 1 facing the substrate 11, the electrical contact 10 of the MEMS chip 1 is formed in the form of a solder pad. A metallization 23, also referred to as "under bump metallization," is arranged on a side of the contact 10 facing the substrate 11. The electrical contact also extends laterally beyond the solder pad and runs along the underside of the MEMS chip 1.

A further stress relief layer 25 is arranged between the MEMS chip 1 and the electrical contact 10 of the MEMS chip 1, which is designed as a solder pad. The further stress relief layer 25 is designed to reduce mechanical stresses between the MEMS chip 1 and the substrate 11. In an alternative embodiment, a stress relief layer 25 can be arranged either only on the substrate 11 or only on the underside of the MEMS chip 1.

A solder ball 16 is arranged between the part of the electrical contact 10 of the MEMS chip 1 formed as a solder pad and the part of the inner electrical contact 13 of the substrate 11 formed as a solder pad. The substrate 11 and the MEMS chip 1 are mechanically connected to one another and electrically contacted via the solder ball 16.

The electrical contacts 10, 13 and the stress relief layers 25 on the MEMS chip 1 and on the substrate 11 are each surrounded by a solder stop layer 26.

Figure 9 shows a further exemplary embodiment, showing a detailed illustration of a MEMS chip 1 arranged on a substrate 11. In contrast to the embodiment shown in Figure 8, the metallization 23 here extends not only along the underside of the MEMS chip 1, but also runs on a side surface of the first silicon layer 7, which is perpendicular to the underside. Accordingly, an under bump metallization with an L-shaped cross section is obtained.

The MEMS chip 1 shown in Figure 9 does not have a stress relief layer 25.

Figures 10 to 12 show a further embodiment of a MEMS chip 1 mounted on the substrate 11. The electrical contacts 10 of the MEMS chip 1, which are designed as solder pads, are partially surrounded by a slot 27 through the MEMS Chip 1 is surrounded. The slot 27 surrounds the respective electrical contact 10 on three sides. As a result, the MEMS chip 1 is designed as a spring-loaded suspension in the area of the electrical contacts 10.

The MEMS chip 1 is constructed in such a way that mechanical stresses are reduced, particularly in the regions in which the electrical contacts 10 surrounded by the slots 27 are arranged. In contrast, the regions of the MEMS chip 1 in which no electrical contacts 10 are arranged and in which the movable element 2 of the MEMS chip 1 and the drive elements 3 are formed instead experience no or only slight mechanical stress.

Figures 11 and 12 show a cross-section of the MEMS chip 1 mounted on the substrate 11. In Figure 11, there is no mechanical stress between the substrate 11 and the MEMS chip 1. Accordingly, the MEMS chip 1 is essentially planar.

In Figure 12, due to different thermal expansion coefficients, mechanical stress occurs between the MEMS chip 1 and the substrate 11. It can be seen that the regions in which the electrical contacts 10 are formed experience significant deformation, while a central region in which the movable element 2 is formed does not experience any deformation. By forming the MEMS chip 1 with a spring-loaded suspension in its edge regions, an optically relevant central region of the MEMS chip 1 can be protected from undesired deformations, which can occur, for example, due to different thermal expansion coefficients of the MEMS chip 1 and the substrate 11. The design of the MEMS chip 1 with a spring-loaded

Suspension can thus be used as an alternative to the stress relief layers 25 shown in Figures 8 and 9. Alternatively, the spring-loaded suspension can be combined with a stress relief layer 25 on the MEMS chip 1 and/or on the substrate 11.

Figure 13 shows a frame 17 which is connected to the substrate 11 via an adhesive connection 28.

The substrate 11 has the external electrical contact 14 for further contacting, for example with a printed circuit board or an external power supply. The external electrical contact 14 lies outside an encapsulated area in which the MEMS chip 1 is enclosed by the substrate 11 and the frame 17.

The inner electrical contact 13 of the substrate 11, which is connected to the MEMS chip 1, and the external contact 14 are connected to one another via a conductor track 29. In the region of the inner electrical contact 13 of the substrate 11 within the frame 17, the conductor track 29 is covered by a solder stop layer 26. The conductor track 29 does not run along the adhesive connection 28. Instead, the conductor track 29 runs in an inner layer of the substrate 11 in the region of the adhesive connection 28.

Figure 14 shows a substrate 11 and a frame 17, which were manufactured in a common additive manufacturing process, for example, a 3D printing process. In the additive manufacturing process, the conductor tracks 29 formed in or on the substrate 11 are also simultaneously produced. and the electrical contacts 13, 14 of the substrate 11 are manufactured.

An adhesive connection 28 between frame 17 and substrate 11 can be dispensed with. The conductor track 29 runs close to the surface of the substrate 11 and is covered by a thin ceramic layer 30 which is produced on the conductor track 29 in the additive manufacturing process. The conductor track 29 is connected to the external contact 14, which is exposed and not covered by the thin ceramic layer 30. An additional solder stop layer 26 covering the conductor track 29 can be dispensed with, since the additively manufactured thin ceramic layer 30 takes over this function. By manufacturing by means of an additive manufacturing process, the laying of the conductor track 29 in the inner layer in the region of the adhesive connection 28 and the use of the solder stop layer 26 on the conductor track 29 in the region of the external electrical contact 14 of the substrate 11 can be dispensed with.

Figure 15 shows a package having the MEMS chip 1 arranged on the substrate 11. The package further comprises an encapsulation which, together with the substrate, forms a hermetically sealed cavity in which the MEMS chip 1 is arranged.

The encapsulation comprises the frame 17 and a window 33 . The frame 17 may comprise a ceramic material or a glass or be made of a ceramic material or glass . The frame 17 may comprise the same material as the substrate 11 or as the window 33 or be made of this material . The material of the frame 17 has a thermal expansion coefficient which is similar to the thermal expansion coefficient of the substrate 11 , so that the occurrence of mechanical stresses can be reduced or completely avoided .

The window 33 is transparent to light rays, in particular laser beams, in the visible spectrum. The window 33 is arranged obliquely to a surface of the substrate 11. The window 33 comprises a glass or a ceramic material. Alternatively, the window 33 can be made of a glass or a ceramic material. The substrate 11, the frame 17 and the window 33 can comprise the same material. The thermal expansion coefficient of the window 33 is very similar to the thermal expansion coefficient of the substrate 11 and the frame 17.

The window 33 may have an anti-reflective coating on its inner side facing the cavity and/or on its outer side facing away from the cavity. The window may be made of a ceramic material.

The window 33 is inclined towards the top side of the substrate 11. The window 33 is inclined towards the movable element 2 of the MEMS chip 1 when the movable element 2 is in its rest position. The window 33 can enclose an angle of between 5° and 20° with the top side of the substrate 11 and with the movable element 2 of the MEMS chip 1 in the rest position. By inclining the window 33 to the movable element 2 of the MEMS chip 1 in its rest position, it can be ensured that a laser beam which is created by an unwanted reflection at the window 33 does not propagate in the same direction as a signal laser beam. Encapsulation can be carried out under vacuum or under a

Inert gas atmosphere can be sealed. Accordingly, the cavity can be a vacuum or an inert gas atmosphere.

The encapsulation can protect the MEMS chip 1 arranged in the cavity from water, humidity, and other environmental influences, thus preventing corrosion, oxidation, or aging of the MEMS chip 1 caused by other effects. Hermetic encapsulation can also prevent condensation of humidity in the cavity.

The package further comprises spacers 20 which are arranged between the substrate 11 and the part of the internal electrical contacts 13 of the substrate 11 which is designed as a solder pad. The internal electrical contacts 13 of the substrate 11 are arranged on the spacers 20. The spacers 20 increase the distance between the MEMS chip 1 and the substrate 11. This ensures that the distance between the movable element 2 of the MEMS chip 1 and the substrate 11 is sufficiently large so that the movement of the movable element 2 of the MEMS chip 1 is not impaired by the substrate 11.

In the substrate 11, a recess 19 is formed under the movable element 2 of the MEMS chip 1, which prevents mechanical contact of the movable element 2 with the substrate 11. An opening 18 extending through the entire substrate 11 can be dispensed with. The spacers 20 could alternatively be formed so high that the recess of the substrate 11 in the Area in which the movable element 2 of the MEMS chip 1 is arranged can be dispensed with.

Figure 16 shows a further exemplary embodiment. Here, the MEMS chip 1 is connected to the substrate 11 via high solder balls 16. These act in the same way as the spacers 20 arranged on the surface of the substrate 11, which are shown in Figure 15. The height of the solder balls 16 is selected such that the movable element 2 of the MEMS chip 1 does not come into contact with the surface of the substrate 11, even at its maximum deflection. A recess 19 in the substrate 11 can therefore be dispensed with.

Figures 17 and 18 show exemplary embodiments of the package in which an opening 18 extending completely through the substrate 11 is arranged in the substrate 11 and is formed below the movable element 2 of the MEMS chip 1. A frame 17 and a window 33 are arranged on the underside of the substrate 11 facing away from the MEMS chip 1.

In the exemplary embodiment shown in Figure 17, a further frame 17 is fastened to the upper side of the substrate 11, on which side the MEMS chip 1 is also fastened, and to which frame a further substrate 34 is fastened. The cavity in which the MEMS chip 1 is arranged is encapsulated by the substrate 11, the frame 17 arranged on the underside of the substrate, the window 33 connected to this frame, the frame 17 arranged on the upper side of the substrate and the further substrate 34 connected to this frame. A laser beam can, for example, enter through the window 33 arranged on the underside of the frame 17, be reflected by the movable element 2 of the MEMS chip 1 and exit again through the window 33. For this purpose, the movable element 2 has a reflective coating on its underside. The window 33 is inclined relative to the movable element 2 when the movable element 2 is in its rest position. The window 33 encloses an angle of between 5 and 20° with the movable element 2 in its rest position, for example.

In the embodiment shown in Figure 17, the internal electrical contact 13 on the top side of the substrate 11 is connected via conductor tracks 29 in the substrate 11, in the frame 17 and in the further substrate 35 fastened to the frame 17 to an external electrical contact 14 which is formed on a top side of the further substrate 34.

On the side of the MEMS chip 1 facing away from the substrate 11, a mechanical reinforcement structure 35 of the movable element 2 is formed. This can be, for example, a beam structure that prevents distortion of the movable element 2 during its deflection. The MEMS chip 1 is manufactured from an SOI wafer, with the second silicon layer 8 being patterned to form the reinforcement structure 35.

In the embodiment shown in Figure 18, a frame 17 is also arranged on an upper side of the substrate 11. Instead of a further substrate 34, the frame 17 is closed on the upper side by a second window 33. An encapsulation of the cavity in which the MEMS chip 1 is arranged is formed by the substrate 11, the two frames 17 and the two windows 33. The two windows 33 are arranged such that a first laser beam can be directed from an underside of the package onto the movable element 2 of the MEMS chip 1. Furthermore, a second laser beam can be directed from an upper side of the package onto the movable element 2 of the MEMS chip 1 through the window 33 arranged on the upper side of the substrate 11. One of the two laser beams can be the signal laser beam which is deflected by the movable element 2 to generate an image. The other of the two laser beams can be used to monitor a deflection of the movable element 2.

The movable element 2 has a reflective coating on both its underside facing the substrate 11 and its upper side facing away from the substrate 11. In the embodiment shown in Figure 18, the MEMS chip 1 has a single silicon layer 7.

Figures 19 to 21 show various possibilities for connecting an internal electrical contact 13 of the substrate 11, which is connected to the MEMS chip 1, to an external contact 14 of the substrate 11, via which the substrate 11 can be connected to an external voltage supply or a printed circuit board.

Figure 19 shows vias 24 which run from a top side of the substrate 11, on which the inner electrical contact 13 is arranged, which is connected to the MEMS chip 1, to a bottom side of the substrate 11, on which the external contact 14 is arranged , which is designed to be connected to an external power supply or a printed circuit board .

Figure 20 shows a conductor track 29 arranged along the upper side of the substrate 11. The conductor track 29 runs from the inner contact 13 of the substrate 11, which is connected to the MEMS chip 1 and is arranged within the encapsulated cavity, under the frame 17 into an area outside the cavity. Here, the substrate 11 can be contacted via the external electrical contact 14 and, for example, connected to an external voltage supply. Details of the design of the conductor track 29 were explained in connection with Figures 13 and 14.

Figure 21 also shows the contacting via a conductor track 29, which runs along the top side of the substrate 11 out of the cavity. The conductor track 29 additionally extends over a side surface of the substrate 11, which is perpendicular to the top side. The conductor track 29 extends partially over an underside of the substrate 11, which faces away from the MEMS chip 1. The external electrical contact 14, which is provided for external contacting, is formed on the underside of the substrate 11.

Figure 22 shows a further exemplary embodiment of the package. The package comprises the substrate 11, the MEMS chip 1 mounted on the substrate 11 in a flip-chip design, a laser module 36, control electronics 37 for controlling the laser module 36, an AS IC 38 configured to control the MEMS chip 1, and optical components such as a mirror 39 and a reflective coating 40. The substrate 11 has an opening 18 arranged next to the MEMS chip 1, which opening is closed by a window 33. The substrate 11, the frame 17, the window 33 that closes the frame 17, and the window 33 that closes the opening 18 in the substrate 11 enclose a cavity in which the MEMS chip 1 is encapsulated. The reflective coating 40 is applied to an underside of the window 33 that closes the frame 17, facing the cavity.

The laser module 36 is arranged on an underside of the substrate 11. The control electronics 37 of the laser module 36 is arranged on an upper side of the substrate 11. The control electronics 37 is connected to the laser module 36 via vias 24 through the substrate 11. The laser module 36 is designed to emit a laser beam. The laser module 36 has one or more laser diodes.

A mirror 39 is arranged on the underside of the substrate 11. The laser module 36, the mirror 39 and the window 33 are arranged such that a laser beam emitted by the laser module 36 is reflected by the mirror 39 and enters the encapsulated cavity through the window 33. The reflective coating 40 is arranged in the cavity such that it reflects the incoming laser beam in the direction of the movable element 2. The laser beam reflected by the reflective coating 40 strikes the movable element 2 of the MEMS chip 1 and is reflected again by the latter. The laser beam reflected by the movable element 2 then leaves the encapsulated cavity through the window 33. The AS IC 38 is arranged on the underside of the substrate 11 and is connected to the internal electrical contacts 13 of the substrate 11, which are connected to the MEMS chip 1, via vias 24 which run through the substrate 11.

Figure 23 shows a further exemplary embodiment. In comparison to the exemplary embodiment shown in Figure 22, the laser module 36 is now arranged on the upper side of the substrate 11, and the control electronics 37 are arranged on the underside of the substrate 11. Furthermore, the opening 18 of the substrate 11 next to the MEMS chip 1 and the window 33 arranged on the underside of the substrate 1 are omitted. The mirror 39, which effects the first deflection of the laser beam, is arranged here within the encapsulated cavity.

Figure 24 shows a further exemplary embodiment of the package. In the exemplary embodiment shown in Figure 24, frames 17 are arranged on both the top side of the substrate 11 and the underside of the substrate 11, each frame being closed by a window 33. The frames 17 and the windows 33 are transparent to a laser beam. A reflective coating 40 is arranged on the inside of each of the two windows 33. The substrate 11 has an opening 18 which is formed below the movable element 2 and which extends completely through the substrate 11.

The package has two laser modules 36 , each designed to emit a laser beam . Within the encapsulated cavity are two stationary , obliquely arranged mirrors 39 , which Laser beams are deflected respectively. The laser beam emitted by the laser module 36 on the upper side of the substrate 11 is deflected by the mirror 39 on the upper side, strikes the reflective coating 40 of the window 33 on the upper side and then strikes the upper side of the movable element 2 of the MEMS chip 1, which has a reflective layer. The laser beam emitted by the laser module 36 on the underside of the substrate 11 is deflected by the mirror 39 on the underside, strikes the reflective coating 40 of the window 33 on the underside, passes through the opening 18 in the substrate 11 and then strikes the underside of the movable element 2 of the MEMS chip 1, which has a reflective layer.

One of the two laser beams can be used as a signal laser beam to generate an image. The other of the two laser beams can be used as a sensor laser beam to monitor the position and deflection of the movable element.

It is also possible to arrange the laser module 36 within the encapsulated cavity. One such embodiment is shown in Figure 25. In the embodiment shown in Figure 25, the MEMS chip 1, the laser module 36, and optical components, in particular lenses 41 and mirrors 39, are arranged within the encapsulated cavity. The control electronics 37 for the laser module 36 and the AS IC 38 are arranged on the underside of the substrate 11 and thus outside the encapsulated cavity.

The control electronics 37 for the laser module 36 is connected to the substrate 11 via vias 24. Laser module 36 is connected. A laser beam emitted by the laser module 36 first passes through two lenses 41 and is then deflected by two stationary mirrors 39 in such a way that it strikes the movable element 2 of the MEMS chip 1. The laser beam is deflected by the movable element 2 in such a way that the laser beam exits the encapsulated cavity through the window 33.

Figure 26 shows a further exemplary embodiment in which the encapsulation has two windows 33 arranged parallel to one another. A first window 33 can be used for a light entry through which a laser beam enters the encapsulated cavity, and the second window 33 can be used as a light exit through which the laser beam exits the encapsulated cavity.

Figure 27 shows a further embodiment of the package with a window 33 arranged obliquely to the MEMS chip 1.

In the embodiments shown in Figure 26 and Figure 27, the encapsulation arranged on the substrate 11 can be made of glass.

Figures 28 and 29 show embodiments in which the encapsulation has two windows 33 arranged obliquely to one another. In the embodiment shown in Figure 28, a reflective coating 40 is arranged on the inside of one of the windows 33. In this case, the other window 33 is used for both the entry and exit of the laser beam. In the embodiment shown in Figure 29, the windows 33 do not have a reflective coating 40. The laser beam enters the encapsulated cavity via a first window 33, is reflected by the movable element 2 of the MEMS chip 1 and leaves the encapsulated cavity via the second window 33 .

Figure 30 shows another exemplary embodiment of the package. The substrate 11 and the frame 17 were manufactured using an additive manufacturing process.

In the additive manufacturing process, a fastening foot 42 of the substrate 11 is additionally formed, which makes it possible to be fastened to a printed circuit board. The fastening foot 42 can be arranged at an angle to the other elements of the package. The fastening foot 42 is at an angle to the movable element 2 of the MEMS chip 1 in its rest position and at an angle to the window 33. If the fastening foot 42 is now fastened to the printed circuit board, the substrate 11 and the MEMS chip 1 are arranged at an angle to the printed circuit board, i.e. the substrate 11 and the MEMS chip 1 are neither parallel nor perpendicular to the substrate.

By adding the mounting foot 42 and selecting an appropriate angle between the mounting foot 42 and the substrate 11 of the package, any angle between the substrate 11 and a printed circuit board can be selected. In this way, the substrate 11 and the MEMS chip 1 can be arranged at an angle to a laser source, ensuring that reflections of a laser beam do not propagate in the same direction as a signal laser beam.

Figure 31 shows another embodiment. The substrate

11 is here in an additive manufacturing process together with the mounting foot 42. The substrate 11 is arranged at an angle to the mounting foot 42. Further elements of the package, for example, the ASIC 38, are arranged on the mounting foot 42. By combining it with the mounting foot 42, the substrate 11 can be arranged at any angle to a printed circuit board.

Figure 32 shows a further embodiment in which the substrate 11 is manufactured using an additive manufacturing process and has a bend 43. A part of the substrate 11 in which the MEMS chip 1 is arranged is formed obliquely relative to another part of the substrate 11 in which the laser module 36 is arranged.

In this embodiment, the bend 43 takes over the functionality of the fastening foot 42. By means of the bend 43, the substrate 11 can be fastened to a circuit board in such a way that the MEMS chip 1 and the window 33, from which the deflected laser beam emerges, are arranged obliquely to the circuit board.

The encapsulation has a two-part cover 44 to replicate the shape of the substrate 11. As in the embodiment shown in Figure 25, the laser module 36 and optical components are arranged in the encapsulated cavity.

Figure 33 shows the package in a perspective view. Figure 33 shows the MEMS chip 1, the substrate 11, the frame 17, and the window 33. The substrate 11 has a rectangular base. The frame 17 is ring-shaped, with an upper side of the frame 17, which faces away from the substrate 11, being slanted. The window attached to the frame 17 33 is arranged obliquely to the substrate 11. The frame 17 is fastened to the substrate 11 by means of metallic bonding. The drive elements 3 are arranged on the side of the MEMS chip 1 facing the substrate 11. A reflective layer 21 is applied to the side of the MEMS chip facing away from the substrate 11. The MEMS chip 1 is fastened to the substrate 11 in a flip-chip design. The electrical contacts 10 of the MEMS chip 1 are soldered to internal electrical contacts 10 on the top side of the substrate 11.

Conductor tracks 29 and electrical contacts 13, 14 are arranged on the substrate 11. The substrate 11 has internal electrical contacts 13, which are arranged in the encapsulated cavity, and external electrical contacts 14, which are arranged outside the encapsulated cavity. The conductor tracks (not shown) each connect an internal electrical contact 13 to an external electrical contact 14. A mechanical and electrical contact is established between the substrate 11 and the MEMS chip 1 via the internal electrical contacts 13.

The annular frame is formed on the substrate 11. This frame has a beveled surface that is tilted relative to the MEMS chip 1 and the substrate 11. This tilted surface can be easily produced using an additive manufacturing process. Such shapes are almost impossible to produce using conventional manufacturing techniques, at least not without mechanical post-processing or in a single, homogeneous component that is free of internal joints. Figure 34 shows a second exemplary embodiment of a package. This essentially has the same components as the package shown in Figure 33. In this exemplary embodiment, the substrate 11 has a round outer shape.

In addition, first and second inner contacts 13a, 13b of the substrate 11 are realized, of which only one is provided with a reference symbol by way of example. The first and second inner contacts 13a, 13b of the substrate 11 are arranged in the encapsulated cavity. The first and second inner contacts 13a, 13b enable or facilitate the separation of the electrical and mechanical connection. For example, electrical contact with the MEMS chip 1 to be installed can be established primarily or exclusively via the first inner contact 13a. The mechanical fastening can then be formed primarily or completely by the second inner contact 13b.

Furthermore, the substrate has a position marker 45. The position marker 45 is designed to facilitate the placement (so-called "pick and place") of the component to be installed.

The following figures show the production of the package.

Figure 35 shows the package on the left after solder balls 16 have been applied to the first inner contacts 13a of the substrate 11. The package is shown on the right in a state in which the MEMS chip 1 is attached to the solder balls 16. The MEMS chip 1 can be fixed by a reflow soldering process, wherein the MEMS chip 1 is aligned taking into account the position marker 45. Figure 36 shows the package after the window 33 has been attached to the frame 17. The window 33 is attached to the frame 17 by means of a metal joining agent. Furthermore, driver components have been applied to the substrate 11 outside the frame 17. The driver components are the AS IC 38 and the control electronics 37 for the laser module.

A sensor 46 is mounted on the substrate 11 outside the encapsulated region. The sensor 46 can be configured, for example, to measure acceleration and/or temperature and/or humidity and/or brightness.

Figure 37 shows another exemplary embodiment of the package. Here, a bonding wire 15 has also been attached, which contacts the MEMS chip 1 with internal electrical contacts 13 of the substrate 11 within the cavity. Additionally, a protective component 47 is arranged in the cavity and electrically connected to the MEMS chip 1. The protective component 47 can be a varistor or a TVS diode.

A driver component, for example, the AS IC 38, is also arranged in the cavity and connected to bond wires 15 for contacting. Additionally, a sensor 46 is arranged in the cavity and contacted to bond wires 15. The sensor 46 can be configured to measure pressure, temperature, and/or acceleration.

Figure 38 shows the package mounted on a circuit board.

The circuit board has circuit elements for controlling the MEMS chips 1 and the laser module. The package is connected to contacts on the circuit board via two bond wires 15.

Figure 39 schematically shows a method for producing the packages shown above. In a first step S1, a plurality of MEMS chips 1 are attached to a wafer, each MEMS chip 1 having electrical components on one side and the MEMS chips 1 being attached to the wafer such that the side on which the electrical components are arranged faces the wafer. In a subsequent step S2, the wafer is singulated. In a then following step S3, the packages are encapsulated by applying the encapsulation. The packages are thus encapsulated at die level.

Figure 40 shows a device 48 for aligning the package. The device 48 is designed to move, in particular to tilt, the substrate 11 and the MEMS chip 1 connected thereto relative to a holder 49. For this purpose, the device 48 can move the substrate 11 by means of a flexible membrane, by means of a microfluidic pump or by means of one or more piezoelectric actuators. The holder 49 can be fastened to a printed circuit board, for example. The device 48 for aligning the package can make it possible to tilt the substrate 11 and the MEMS chip 1 relative to the printed circuit board.

Figure 41 shows an embodiment in which the drive elements 3 for moving the movable element 2 of the MEMS chip 1 are not arranged on the MEMS chip 1, but on the substrate 11. The MEMS chip 1 is arranged directly on the drive elements 3 and is glued to them, for example. One of the drive elements 3 The movement generated is transferred to the MEMS chip 1 via an adhesive layer 50.

Figures 42 and 43 show a package designed to determine a deflection of the movable element 2. The movable element 2 is partially transparent for at least some wavelengths. A light-sensitive element 51 is arranged in a region of the substrate 11 that lies beneath the movable element 2.

A light beam striking the movable element 2 is partially reflected by the movable element 2. Part of the light beam striking the movable element 2 passes through the movable element 2 and is refracted at two interfaces.

Figure 42 shows the movable element 2 in its rest position. The laser beam strikes the movable element 2 perpendicularly. The part of the laser beam that passes through the movable element 2 is not deflected by the movable element 2 and strikes the light-sensitive element 51 centrally.

Figure 43 shows the movable element 2 in a deflected position. The laser beam striking the movable element 2 partially passes through the movable element 2 and is refracted twice. As a result, the laser beam emerging from the movable element 2 is laterally offset in its propagation direction compared to the laser beam striking the movable element 2. The laser beam strikes the light-sensitive element 51 in a laterally offset position. The light-sensitive element 51 can detect the position at which it is struck by the laser beam. From this information, the deflection of the movable element 2 can be determined.

Figures 44 and 45 show a package in which the deflection of the movable element 2 is also determined via a light-sensitive element 51. The light-sensitive element 51 is arranged on the side of the movable element 2 facing the light entry window 33. Alternatively, the light-sensitive element 51 could be integrated into the movable element 2 or arranged on the side of the movable element 2 facing away from the light entry window 33. Depending on the angle between the movable element 2 and the incoming laser beam, a larger area of the light-sensitive element 51 is hit by the laser beam. This is measured by the light-sensitive element 51. The deflection of the movable element 2 can be determined from this information. Figures 44 and 45 show the movable element 2 at different angles to the incoming laser beam.

Figures 46 and 47 show a package in which the deflection of the movable element 2 is also determined via light-sensitive elements 51. The light-sensitive elements 51 are arranged in a region of the window 33 through which a beam deflected by the movable element 2 leaves the package. Depending on the deflection of the movable element 2, a different light-sensitive element 51 or no light-sensitive element 51 is hit by the deflected laser beam. It can be determined at what time which of the light-sensitive elements 51 was hit by the laser beam. From this information the deflection of the movable element 2 can be determined.

Figure 46 shows the movable element 2 in its rest position, wherein the deflected laser beam does not hit any of the light-sensitive elements 51. Figure 47 shows the movable element 2 in a deflected position, wherein the deflected laser beam hits one of the light-sensitive elements 51.

Figure 48 also shows a package in which light-sensitive elements 51 are arranged on the inside of the window 33. In addition to the signal laser beam 52, a measuring laser beam 53 enters the package, with both laser beams being directed onto the movable element 2 and with both laser beams striking the movable element 2 at a different angle. The measuring laser beam 53 is reflected by the movable element 2 and strikes one of the light-sensitive elements 51 depending on the deflection of the movable element 2. The deflection of the movable element 2 can then be determined based on the measured values measured by the light-sensitive elements 51.

In the embodiments shown in Figures 42 to 48, the drive elements 3 are each arranged on the substrate. The drive elements 3 can be actuators, in particular piezoelectric actuators.

Figure 49 also shows a package in which a measuring laser beam 53 is used to determine the deflection of the movable element 2. The measuring laser beam 53 enters through a window 33 arranged on the underside of the substrate 11. The signal laser beam 52 enters through another window 33. The signal laser beam 52 enters via a

Window 33, which is arranged on the frame 17 above the MEMS chip 1. The package further comprises a light-sensitive element 51, onto which the measuring laser beam 53 is reflected depending on the deflection of the movable element 2.

Based on the measured values measured by the light-sensitive elements 51, the deflection of the movable element 2 can then be determined.

Reference symbol list

1 MEMS chip

2 (movable) element / mirror element

3 Drive element

4 first spring element

5 rigid area

6 second spring element

7 first silicon layer

8 second silicon layer

9 Etch stop layer

10 electrical contact of the MEMS chip

11 Substrat

12 adhesive layer

13 internal contacts of the substrate

13a, 13b inner contacts of the substrate

14 external contacts of the substrate

15 bonding wire

16 solder balls

17 frames

18 Opening

19 Deepening

20 spacers

21 reflective layer

22 Mirror suspension

23 Metallization

24 vias

25 Stress Relief Layer

26 Solder mask layer

27 slot

28 Adhesive bond

29 Conductor track

30 thin ceramic layer 31a, 31b first control area

32a, 32b second control area

33 windows

34 additional substrate

35 mechanical reinforcement structure

36 laser module

37 Control electronics

38 AS IC

39 mirrors

40 reflective coating

41 lens

42 Mounting foot

43 Bending of the substrate

44 lids

45 position markers

46 Sensor

47 Protective component

48 Alignment device

49 Bracket

50 Adhesive layer 51 Light-sensitive element

52 Signal laser beam

53 Measuring laser beam

SA short axis

LA long axis

Claims

Patent claims 1. Package comprising a substrate (11) and a MEMS chip (1), wherein the MEMS chip (1) is attached to the substrate (11). 2. Package according to claim 1, wherein the MEMS chip (1) has at least one electrical component (3). 3. Package according to claim 2, wherein the at least one electrical component (3) is arranged on the side of the MEMS chip (1) facing the substrate, or wherein the at least one electrical component (3) is arranged on the side of the MEMS chip (1) facing away from the substrate. 4. Package according to one of the preceding claims, comprising at least one electrical component (3) which is arranged on the side of the MEMS chip (1) facing the substrate, and at least one electrical component (3) which is arranged on the side of the MEMS chip (1) facing away from the substrate. 5. Package according to one of the preceding claims, wherein the MEMS chip has a movable element. 6. Package according to one of the preceding claims, wherein the MEMS chip (1) is mounted on the substrate (11) in flip chip design. 7. Package according to one of the preceding claims, wherein the MEMS chip (1) has, on the side facing the substrate (11), electrical contacts (10) which are connected to electrical contacts (13) of the substrate (11). 8. Package according to the preceding claim, wherein the electrical contacts (10) of the MEMS chip (1) are additionally arranged on a side surface of the MEMS chip (1) which is perpendicular to the substrate (11). 9. Package according to one of claims 7 or 8, wherein the electrical contacts (10) of the MEMS chip are connected to the electrical contacts (13) of the substrate (11) via solder balls (16). 10. Package according to claim 5 and claim 9, wherein a height of the solder balls (16) is selected such that the movable element (2) does not strike the substrate (11) during movement. 11. Package according to one of claims 7 to 10, wherein the substrate (11) has a via (24) via which one of the electrical contacts (13) of the substrate (11) is connected to an external electrical contact (14) arranged on the side of the substrate (11) facing away from the MEMS chip (1), and/or wherein the substrate (11) has a conductor track (29) via which one of the contacts of the substrate (11) is contacted with an external electrical contact (14) of the substrate (11), which contact is located on an upper side of the substrate (11) facing the MEMS chip (1) or on a side surface of the substrate (11) which is perpendicular to the upper side. 12. Package according to one of claims 7 to 11, wherein the electrical contacts (10) of the MEMS chip (1) are partially enclosed by a slot (27) in the MEMS chip (1). 13. Package according to the preceding claim, wherein the MEMS chip (1) has a higher deformability in a region in which the slots (27) partially enclose the electrical contacts (10) than in an active region which has the electrical component (3). 14. Package according to one of the preceding claims, wherein the MEMS chip (1) is electrically contacted to the substrate (11) by bonding wires (15). 15. Package according to one of the preceding claims, wherein the MEMS chip (1) has a single silicon layer (7). 16. Package according to one of the preceding claims, wherein a stress relief layer (25) is provided between the substrate (11) and the MEMS chip (1). 17. Package according to one of the preceding claims, wherein the substrate (11) has a spacer (20) on the side facing the MEMS chip (1), against which the MEMS chip (1) rests. 18. Package according to one of the preceding claims, wherein the substrate (11) has a recess (19) on the side facing the MEMS chip (1), above which a movable element (2) of the MEMS chip (1) is arranged. 19. Package according to the preceding claim, further comprising an encapsulation which, together with the substrate (11), encapsulates a cavity in which the MEMS chip (1) is arranged. 20. Package according to one of the preceding claims, wherein the encapsulation has a window (33). 21. Package according to the preceding claim, wherein the window (33) has an anti-reflective coating. 22. Package according to claim 20 or claim 21, wherein the window (33) encloses an angle of between 5° and 20° with a surface of a movable element (2) of the MEMS chip (1) in the rest state of the movable element (2). 23. Package according to one of the preceding claims, wherein the encapsulation has two windows (33). 24. Package according to the previous claim, wherein the windows (33) form an angle between Include 10° and 170°. 25. Package according to claim 24, wherein the two windows (33) are opposite each other. 26. Package according to one of claims 19 to 25, wherein at least part of the encapsulation is manufactured using an additive manufacturing process. 27. Package according to one of the preceding claims, wherein the substrate (11) is manufactured using an additive manufacturing process. 28. Package according to one of the preceding claims, wherein the electrical component (3) comprises a piezoelectric actuator. 29. Package according to claim 5 and one of the preceding claims, wherein the MEMS chip (1) comprises a MEMS micromirror, wherein the movable element (2) is a movable mirror element (2). 30. Package according to claim 29, wherein the movable mirror element (2) has a reflective layer arranged on the side of the MEMS chip (1) facing the substrate (11). 31. Package according to one of claims 29 to 30, wherein the movable mirror element (2) has a reflective layer which is arranged on the side of the MEMS chips (1) are arranged, which point away from the substrate (11). 32. Package according to one of claims 29 to 31, wherein the movable mirror element (2) has a mechanical reinforcement structure (35) on a side facing away from the reflective layer. 33. Package according to one of the preceding claims, wherein an ASIC (38), a laser module (36) and/or control electronics (37) for controlling the laser module (36) are arranged on the substrate (11). 34. Package according to one of the preceding claims, wherein at least one optical component, for example a mirror (39) or a lens (41), is arranged on the substrate (11). 35. Package according to one of the preceding claims, wherein at least one sensor (46) is arranged on the substrate (11). 36. Package according to one of the preceding claims, wherein a microscopic fluid channel is formed in the substrate (11). 37. Package according to the preceding claim, wherein the package is designed to pump a liquid, for example water or glycol, through the microscopic fluid channel for adjusting the temperature of the MEMS chip (1) and/or other components of the package. 38. Package according to one of the preceding claims, wherein the substrate (11) has a mounting foot (42) for mounting on a circuit board, which is arranged obliquely to the MEMS chip (1), so that the package can be mounted on the circuit board in such a way that the MEMS chip (1) is arranged obliquely to the circuit board. 39. Package according to one of the preceding claims, wherein the substrate (11) has a bend (43). 40. Package according to one of the preceding claims, comprising a device (48) for aligning the package, which device is designed to move, for example tilt, the substrate (11) relative to a holder (49). 41. Package according to the preceding claim, wherein the device (48) comprises a flexible membrane, a microfluidic pump and/or a piezoelectric actuator. 42. Package according to one of the preceding claims, wherein at least one actuator (3) is arranged on the substrate (11) which is designed to move the MEMS chip (1). 43. Package according to the preceding claim, wherein the at least one actuator (3) is a piezoelectric actuator. 44. Package according to claim 5 and one of claims 42 or 43, wherein the actuator (3) is designed to move the movable element (2) of the MEMS chip (1). 45. Package according to claim 5 and one of the preceding claims, wherein the package comprises a device (48) for determining a deflection of the movable element (2). 46. Package according to claim 45, wherein the device (48) for determining a deflection of the movable element (2) comprises a light-sensitive element (51). 47. Package according to claim 46, wherein the deflection of the movable element (2) is determined by evaluating a measurement signal received by the light-sensitive element (51). 48. Package according to one of claims 46 or 47, wherein the light-sensitive element (51) is arranged on the movable element (2). 49. Package according to one of claims 46 or 47, wherein the light-sensitive element (51) is arranged such that a light beam deflected by the movable element (2) strikes the light-sensitive element (51). 50. Package according to one of claims 46 or 47, wherein the movable element (2) is at least partially transparent to light of a wavelength range, wherein the light-sensitive element (51) is arranged on the substrate (11) in such a way that a light beam passing through the movable element (2) strikes the light-sensitive element (51). 51. Package according to claim 45, comprising a light source for emitting a measuring laser beam (53), which is arranged such that the measuring laser beam (53) strikes the movable element (2), wherein a deflection of the movable element (2) is determined by measuring the deflection of the measuring laser beam (53) by the movable element (2). 52. Package according to claim 51, wherein light-sensitive elements (51) are arranged in the regions of the package into which the movable element (2) reflects the measuring laser beam (53) during its various deflections. 53. Package according to claim 51 or 52, wherein the measuring laser beam (53) enters the package either from a top side or a bottom side. 54. Package according to claim 45, wherein the device (48) for determining the deflection of the movable element (2) comprises a sound pressure sensitive sensor which is located either on the MEMS chip (1) or on the substrate (11). 55. Package according to claim 45, wherein the movable element (2) is an electronic Component which charges itself by movement in air, wherein the device (48) for determining the deflection of the movable element (2) has an inductive or capacitive sensor which is designed to measure an electric field which is generated by the electronic component which charges itself by movement in air. 56. Package according to claim 55, wherein the inductive or capacitive sensor is arranged on the substrate (11) or on the MEMS chip (1) or is integrated into the MEMS chip (1). 57. Package according to one of the preceding claims, wherein the MEMS chip comprises a MEMS-based acoustic component, for example a microphone, ultrasonic sensor or loudspeaker. 58. Package according to one of the preceding claims, wherein the MEMS chip comprises a MEMS-based component for measuring physical parameters, for example a pressure sensor, a temperature sensor, a light sensor, a radiation sensor or a magnetic field sensor. 59. Package according to one of the preceding claims, wherein the MEMS chip comprises an inertial sensor, for example an acceleration sensor, a vibration sensor, an inclination sensor or a gyroscope. 60. Package according to one of the preceding claims, wherein the MEMS chip comprises an optical component, for example an image sensor, a mirror element, a scanner element, an interferometer or a laser scanning communication terminal. 61. Package according to one of the preceding claims, wherein the MEMS chip comprises a component for measuring chemical parameters, for example a hydrogen sensor, a gas sensor, a biosensor, a glucose sensor or a lab-on-chip sensor. 62. A method for producing a plurality of packages, comprising the steps of: - Attaching a plurality of MEMS chips (1) on a wafer, - Singling the wafer, and - Encapsulating the packages by means of an encapsulation which, together with the substrate (11), encapsulates a cavity in which the MEMS chip (1) is arranged, this step being carried out after the wafer has been singulated.