DE102022200340A1 - Micromechanical sensor device - Google Patents

Abstract

Micromechanical sensor device (100), comprising:
- At least two MEMS components (10, 20), wherein the MEMS components (10, 20) are each formed as a stacked arrangement of a MEMS element (10b, 20b) with an ASIC element (10a, 20a); whereby
- A second MEMS component (20) is arranged by means of a first adhesive layer (41) on a top side of a first MEMS component (10); whereby
- the at least two MEMS components (10, 20) are at least partially enclosed by a housing (50); whereby
- At least the second MEMS component (20) by means of a 3D rewiring element (23a ... 23c), which extends at least partially over a vertical section of the second MEMS component (20), electrically to a substrate (1) of the micromechanical Sensor device (100) and / or to the first MEMS component (10) is connected.

Description

The present invention relates to a micromechanical sensor device. The present invention also relates to a method for producing a micromechanical sensor device.

State of the art

Micromechanical sensors for measuring acceleration, yaw rate, pressure and other physical variables are mass-produced for various applications in the automotive and consumer sectors.

U.S. 2016 0 362 293 A1 discloses ways to increase the integration density of micromechanical sensors, in which a multistack of three to six "substrates" (these can be wafers or individual chips) are arranged on top of each other in different ways and a highly integrated micromechanical component with at least two CMOS substrates and at least one Form MEMS substrate.

U.S. 2018 254 258 A1 discloses arrangements in which semiconductor chips are electrically contacted neither via bonding wires nor via TSVs, but by means of a so-called 3D-RDL (see also https://www.3dis-tech.com). In this case, a redistribution layer is formed, which partially extends beyond vertical chip edges and thus electrically connects the top side of a semiconductor chip to a housing substrate or to another semiconductor chip.

Disclosure of Invention

One object of the invention is to provide a highly integrated and compact micromechanical sensor device.

• - wenigstens zwei MEMS-Bauelemente, wobei die MEMS-Bauelemente jeweils als gestapelte Anordnung eines MEMS-Elements mit einem ASIC-Element ausgebildet sind; wobei
• - ein zweites MEMS-Bauelement mittels einer ersten Klebeschicht auf einer Oberseite eines ersten MEMS-Bauelements angeordnet ist; wobei
• - die wenigstens zwei MEMS-Bauelemente von einem Gehäuse wenigstens teilweise umschlossen sind; wobei
• - wenigstens das zweite MEMS-Bauelement mittels eines 3D-Umverdrahtungselements, das sich wenigstens teilweise über einen vertikalen Abschnitt des zweiten MEMS-Bauelements erstreckt, elektrisch an ein Substrat der mikromechanischen Sensoreinrichtung und/oder an das erste MEMS-Bauelement angebunden ist.

According to a first aspect, the object is achieved with a micromechanical sensor device, having:

• - At least two MEMS components, wherein the MEMS components are each formed as a stacked arrangement of a MEMS element with an ASIC element; whereby
• - a second MEMS component is arranged by means of a first adhesive layer on a top side of a first MEMS component; whereby
• - the at least two MEMS components are at least partially enclosed by a housing; whereby
• - At least the second MEMS component is electrically connected to a substrate of the micromechanical sensor device and/or to the first MEMS component by means of a 3D rewiring element that extends at least partially over a vertical section of the second MEMS component.

In this way, a combination of at least two so-called ASICap components, which are functionally connected to a substrate of the micromechanical sensor device by means of a 3D rewiring element, is created. In this way, an areal size (footprint) and an overall height of a micromechanical system-in-package (SiP) sensor device can advantageously be minimized.

In addition, the system-in-package approach allows development costs to be kept low, since the individual components integrated there can also be used separately as chip-scale packages, with the exception of comparatively minor technical modifications. In this way, highly integrated and compact micromechanical components can advantageously be implemented as a system in a package. Furthermore, disadvantages associated with wire bonding processes can advantageously be largely avoided.

Advantageously, the proposed sensor device can be used to implement, for example, highly integrated MEMS sensors or actuators with very little installation space. Compared to bonding wires, this arrangement has the advantage that it can be made more compact in the lateral dimensions, i.e. with a smaller grid dimension (English: pitch) of adjacent pads, and also requires no additional space for a bonding wire loop in the vertical direction. Furthermore, unlike when using bond wires, there is no risk of what is known as bond wire sweep due to manufacturing processes, e.g. B. when molding compound flows in at high pressure during the manufacture of mold housings.

• - Bereitstellen von wenigstens zwei MEMS-Bauelementen, wobei die MEMS-Bauelemente jeweils als gestapelte Anordnung eines MEMS-Elements mit einem ASIC-Element ausgebildet sind;
• - Anordnen eines zweiten MEMS-Bauelements mittels einer ersten Klebeschicht auf einer Oberseite eines ersten MEMS-Bauelements;
• - Elektrisches Kontaktieren wenigstens eines der MEMS-Bauelemente mittels eines 3D-Umverdrahtungselements, das sich wenigstens teilweise über einen vertikalen Abschnitt wenigstens eines der MEMS-Bauelemente erstreckt, an ein Substrat der mikromechanischen Sensoreinrichtung; und
• - wenigstens teilweises Umschließen der wenigstens zwei MEMS-Bauelemente von einem Gehäuse.

According to a second aspect, the object is achieved with a method for producing a micromechanical sensor device, having the steps:

• - Providing at least two MEMS components, wherein the MEMS components are each formed as a stacked arrangement of a MEMS element with an ASIC element;
• - arranging a second MEMS component by means of a first adhesive layer on a top side of a first MEMS component;
• - Electrical contacting of at least one of the MEMS components by means of a 3D Rewiring element, which extends at least partially over a vertical section of at least one of the MEMS components, to a substrate of the micromechanical sensor device; and
• - at least partially enclosing the at least two MEMS components in a housing.

Preferred developments of the proposed micromechanical sensor device are the subject of dependent claims.

An advantageous development of the micromechanical sensor device is characterized in that the first MEMS component is electrically connected to a substrate by means of at least one bonding wire.

A further advantageous development of the micromechanical sensor device is characterized in that a passivation element is arranged at least in sections above the second MEMS component on an upper side of the micromechanical sensor device. A package height can be reduced in this way. Furthermore, electrical short circuits can be largely avoided by the passivation film.

A further advantageous development of the micromechanical sensor device is characterized in that the housing is open at least in sections above the second MEMS component on an upper side of the micromechanical sensor device. This is particularly useful for a membrane-based type of sensor, e.g. a microphone or a pressure sensor.

A further advantageous development of the micromechanical sensor device is characterized in that the first MEMS component is connected to the substrate by means of flip-chip assembly or by means of a second adhesive layer. This advantageously provides different options for the functional connection of the first MEMS component to the substrate.

Further advantageous developments of the micromechanical sensor device are distinguished by the fact that all electrical contacts are realized by means of 3D rewiring elements. Advantageously, this means that wire bonds can be completely dispensed with.

Further advantageous developments of the micromechanical sensor device are characterized in that the housing is a molded housing or an open cavity housing. In this way, different types of housing for encapsulating the micromechanical sensor device are advantageously made possible.

A further advantageous development of the micromechanical sensor device is characterized in that molding compound is removed on a top side of the micromechanical sensor device, with a passivation element being arranged at least in sections on the top side of the micromechanical sensor device. In this way, e.g. an electrical contact can be protected effectively and easily.

A further advantageous development of the micromechanical sensor device is characterized in that the mold housing is at least partially exposed on an upper side.

Further advantageous developments of the micromechanical sensor device are distinguished by the fact that an opening is formed at the top in the open cavity housing. Media access for the sensor device can advantageously be provided in this way.

A further advantageous development of the micromechanical sensor device is characterized in that in at least one of the MEMS components a via is formed in the ASIC chip and/or in the MEMS chip. This supports a variety of options for electrical through-connections, which supports a large variety of functions of the sensor device.

A further advantageous development of the micromechanical sensor device is characterized in that the first and/or the second MEMS component has a grid size of the solder balls that is smaller than a standard grid size.

The proposed micromechanical sensor device is described in detail below with further features and advantages based on several figures. Elements that are the same or have the same function have the same reference numbers. The figures are particularly intended to illustrate important principles and are not necessarily drawn to scale. For the sake of better clarity, it can be provided that not all of the reference symbols are drawn in in all of the figures.

Disclosed method features result analogously from corresponding disclosed device features and vice versa. This means in particular that features, technical advantages and designs relating to the micromechanical sensor device correspond in an analogous manner to FIG ending versions, features and advantages of the method for producing a micromechanical sensor device and vice versa.

• 1 eine Querschnittsansicht eines konventionellen mikromechanischen ASICap-Bauelements;
• 2-15 Querschnittsansichten von Ausführungsformen der vorgeschlagenen mikromechanischen Sensoreinrichtung; und
• 16 einen prinzipiellen Ablauf eines Verfahrens zum Herstellen einer vorgeschlagenen mikromechanischen Sensoreinrichtung.

In the figures shows:

• 1 a cross-sectional view of a conventional micromechanical ASICap component;
• 2-15 Cross-sectional views of embodiments of the proposed micromechanical sensor device; and
• 16 a basic sequence of a method for producing a proposed micromechanical sensor device.

Description of Embodiments

A so-called ASICap component (vertically integrated MEMS-ASIC component), which is known per se, comprises an ASIC chip and a MEMS chip, which are mechanically and electrically connected to one another via a metallic bond connection. The metal bond hermetically seals the device to the outer bond frame and also provides electrical contacts. The MEMS chip can be produced, for example, using surface micromechanical methods that are known per se and has a MEMS wafer substrate, oxide layers, a silicon rewiring level and a micromechanical functional layer. The ASIC chip includes an ASIC wafer substrate and various functional layers for transistors and for electrical rewiring.

Proposed is a stacked arrangement of at least a first and a second MEMS component, each consisting of a vertically integrated MEMS and ASIC chip, wherein the second MEMS component is arranged on top of the first MEMS component and at least one of the MEMS components is electrically connected using a 3D rewiring element.

In the following, a “MEMS component” is preferably a component made of a vertically integrated wafer stack, each with an ASIC and MEMS wafer (i.e. vertical integration via wafer bonding, not via stacking of individual ASIC and MEMS chips). As a result, a stacked arrangement of an ASIC element and a MEMS element is formed as a MEMS element.

A rewiring level can be arranged on the upper side of the first MEMS component, which has contacts for the vertical rewiring to the second MEMS component and bonding pads for wire bonds.

The two wafer stacks particularly preferably have through-connections (through silicon vias, TSVs) through the ASIC chip in order to route the ASIC signals from the inside of the wafer stack to the outside of the stack.

Alternatively, the ASIC signals can also be routed through the MEMS chip via MEMS vias to the outside of the wafer stack.

In one variant, the first MEMS component can be arranged on the package substrate by flip-chip assembly, in which case vias are arranged in the underlying chip of the first MEMS component.

In a further variant, it is possible for the first MEMS component to be arranged on the housing substrate with an adhesive film (e.g. die-attach film or a soft silicone adhesive), with vias then being in the chip on top of the first MEMS component are arranged.

A further variant provides that wire bonds are routed onto the housing substrate from the top side of the first MEMS component. Alternatively, electrical signals can be routed from the top to the package substrate via vertical rewiring.

The housing of the proposed sensor device can preferably be designed as a molded housing or as an open cavity housing.

In a further variant, the second MEMS component can be attached to the first MEMS component with an adhesive film (e.g. die-attach film, soft silicone adhesive). In this case, the vias are arranged in the top chip of the second MEMS component.

The first and/or the second MEMS component can advantageously also be used individually as chip scale packages. Appropriate solder balls must be attached for the second MEMS component.

The first and/or the second MEMS device can optionally have a solder ball pitch that is smaller than the standard pitch of 0.4 mm.

The second MEMS device is not necessarily smaller than the first MEMS device ment, but can protrude beyond the first MEMS component along one or more edges.

When using a molded housing, the second MEMS component is typically overmolded on the upper side. Alternatively, the upper side of the second MEMS component can be completely or partially left out of the mold cover.

The electrical connection of the first and also the second MEMS component to the substrate is established via vertical rewiring or a combination of vertical rewiring and wire bonding.

The first and second MEMS component can be a MEMS sensor or actuator. The first and second MEMS component (in any combination) is particularly preferably a yaw rate sensor, an acceleration sensor, a pressure sensor or a combined sensor from the above-mentioned measured variables.

• - erstes MEMS-Bauelement als Drehratensensor, zweites MEMS-Bauelement als Beschleunigungssensor
• - erstes MEMS-Bauelement als IMU (engl. Inertial Measurement Unit), also ein kombinierter dreiachsiger Drehraten- und dreiachsiger Beschleunigungssensor, zweites MEMS-Bauelement als Drucksensor

Exemplary constellations are listed below:

• - First MEMS component as a rotation rate sensor, second MEMS component as an acceleration sensor
• - First MEMS component as an IMU (Inertial Measurement Unit), i.e. a combined three-axis rotation rate and three-axis acceleration sensor, second MEMS component as a pressure sensor

The arrangement can be extended to more than two stacked MEMS devices, e.g. B. three or four stacked MEMS devices. It is also conceivable that, for example, two pairs of stacked MEMS components are arranged next to one another in a common housing.

The overall arrangement of the micromechanical sensor device is advantageously very compact, i. H. both in terms of footprint (housing area) and in terms of the overall height of the SiP, which are minimized compared to conventional solutions. In addition, the overall arrangement requires only little development effort if the first and second MEMS components are already available as individual components, e.g. B. each in the form of chip scale packages were developed. The only additional requirement is therefore the availability of the 3D rewiring technology for realizing the 3D rewiring element.

1 Figure 12 shows a highly simplified cross-sectional view of a conventional vertically integrated ASICap device. One can see a MEMS chip 10b, which together with an ASIC chip 10a by means of solder balls 11 on a substrate 1, which acts as an electrical carrier, for example in the form of a printed circuit board, housing substrate and the like. A via 12 through the ASIC chip 10a produces an electrically conductive connection between the MEMS chip 10b and the ASIC chip 10a. Wiring levels in the printed circuit board that lead further downwards and electrical contact areas on the underside of the substrate 1 are not shown for the sake of better clarity and simplicity.

Furthermore, for these reasons, further technical details in the ASIC chip 10a and in the MEMS chip 10b are not shown and explained. The functional sides of the MEMS and ASIC chip 10b, 10a are typically (but not necessarily) internal, i. H. facing each other, arranged. All of the following considerations are not aimed at a single ASICap component, but rather at an integration of at least two vertically integrated ASICap components that saves as much space as possible. However, it is also conceivable that two or more ASICap components are arranged side by side on a common substrate 1 (double arrangement).

2 shows a first embodiment of a proposed sensor device 100, in which two MEMS components 10, 20 are arranged stacked on top of one another in a vertically integrated ASICap arrangement. The first MEMS component 10 is mounted in an electrically conductive manner on the substrate 1 by means of flip-chip mounting. The second MEMS component 20 is arranged on the first MEMS component 10 with a first adhesive layer 41, for example in the form of a die-attach film or a silicone-like adhesive. In this case, the two MEMS components 10, 20 face one another, as a result of which the second MEMS component 20 has an inverted orientation relative to the first MEMS component 10, ie rotated by 180 degrees. The electrical ASIC signals of the second MEMS component 20 are routed via plated-through holes 22 to the ASIC rear side located at the top.

From there, the ASIC signals are routed to the top of the first MEMS component 10 via a 3D rewiring element 23a. A 3D rewiring element is understood below to mean an electrically conductive rewiring element which has at least one vertical portion, as a result of which a component is electrically contact-connected on a vertical flank. Bond pads (not shown) are additionally arranged in a rewiring level 24 of the first MEMS component 10 , by means of which electrical signals of the second MEMS component 20 can be routed to the substrate 1 via the bonding wires 25 .

In this arrangement, the bonding wire 25 is advantageously routed from the top of the first MEMS component 10 , as a result of which the loop height of the bonding wire 25 is not included in the consideration of the minimum overall height of the sensor device 100 . As a result, the mold coverage only has to be taken into account from the upper edge of the second MEMS component 20 when determining the minimum housing thickness. Copper, for example, can be used as an electrically conductive material for the rewiring level 24, which is provided with an additional surface finish (for example to prevent oxidation or for optimized wire bondability), e.g. B. a nickel-gold layer. However, any material combination that allows the bonding wires 25 to be attached is possible.

• i) Herstellen eines ersten und zweiten MEMS-ASIC-Waferstacks (ASICap),
• ii) Vereinzeln des zweiten MEMS-ASIC Waferstacks, hierbei werden die einzelnen zweiten MEMS-Bauelemente 20 gebildet
• iii) Mechanisches Verbinden der zweiten MEMS-Bauelemente 20 auf dem ersten MEMS-ASIC-Waferstack
• iv) Aufbringen einer Isolationsschicht, z.B. Oxid, auf der MEMS-Rückseite des ersten MEMS-Wafers sowie auf der ASIC-Rückseite und Seitenwand des zweiten MEMS-Bauelements 20
• v) Anordnen (Abscheiden und Strukturieren) der Umverdrahtungsebene auf der MEMS-Rückseite des ersten MEMS-Wafers sowie auf der ASIC-Rückseite und Seitenwand des zweiten MEMS-Bauelements 20. Gegebenenfalls wird eine zusätzliche Passivierschicht aufgebracht, welche an den Bondpads geöffnet wird
• vi) Vereinzeln des in den Schritten i) - v) aufgebauten Waferstacks und Anbringen des vereinzelten Bauelements auf einem entsprechenden Substrat (z.B. auch ein Leadframe oder dergleichen) in einem Flip-Chip-Prozess
• vii) Elektrisches Verbinden des zweiten MEMS-Bauelements 20 auf dem Substrat 1 über eine Drahtbondung
• viii) Ummolden des erzeugten gestapelten Bauelements bei gleichzeitiger Mold-Unterfüllung des stand-off Bereichs des ersten MEMS-Bauelements 10

A process flow for producing the complete micromechanical sensor device 100 can basically look as follows:

• i) producing a first and second MEMS ASIC wafer stack (ASICap),
• ii) Separation of the second MEMS-ASIC wafer stack, in this case the individual second MEMS components 20 are formed
• iii) Mechanically connecting the second MEMS devices 20 on the first MEMS ASIC wafer stack
• iv) Application of an insulation layer, e.g. oxide, on the MEMS rear side of the first MEMS wafer and on the ASIC rear side and side wall of the second MEMS component 20
• v) arranging (depositing and structuring) the rewiring level on the MEMS rear side of the first MEMS wafer and on the ASIC rear side and side wall of the second MEMS component 20. If necessary, an additional passivation layer is applied, which is opened on the bond pads
• vi) Separation of the wafer stack constructed in steps i)-v) and attachment of the separated component to a corresponding substrate (eg also a leadframe or the like) in a flip-chip process
• vii) Electrically connecting the second MEMS device 20 on the substrate 1 via wire bonding
• viii) Molding of the stacked component produced with simultaneous mold underfilling of the stand-off area of the first MEMS component 10

As an exemplary application of the arrangement of 2 the first MEMS component 10 can be a three-axis rotation rate sensor and the second MEMS component 20 can be a three-axis acceleration sensor. In this way, an inertial measurement unit (three-axis rotation rate sensor plus three-axis acceleration sensor) can be formed without the rotation rate sensor and the acceleration sensor having to be arranged on one and the same MEMS chip.

The latter can pose a considerable technical challenge, since the two sensors mentioned have to be operated at different gas pressures in the respective hermetic caverns formed between the MEMS chip and the ASIC chip. If, on the other hand, the two sensors are separated into two chips, it is easier to set the optimum gas pressure for the respective sensor.

The first and second MEMS devices 10, 20 in 2 can also be soldered individually as a chip scale package onto a printed circuit board. In this case, the second MEMS component 20 would still have to be provided with appropriate rewiring and solder balls. In other words, if the first MEMS component 10 and the second MEMS component 20 have already been developed separately as chip scale packages, the arrangement of must be realized 2 only the 3D rewiring element 23 on the upper side of the second MEMS component 20 is adapted and solder balls on the second MEMS component 20 are dispensed with. The arrangement of 2 can thus be advantageously implemented with very little additional development effort.

The arrangement of the micromechanical sensor device 100 of 3 represents a further development of the arrangement of 2 in which no mold cover is used to further reduce the thickness of the housing. The upper side of the second MEMS component 20 is provided with a passivation element 26 and in this case is not molded over at all, but is part of the housing surface and is only surrounded by molding compound on the side. If required, the passivation element 26 can also be attached in the area of the 3D rewiring element 23a and also on the upper side (on which the rewiring to the bond pads is implemented) of the first MEMS component 10 .

This applies equally to the in 2 shown realization of the micromechanical sensor device 100. Compared to 2 this arrangement results in a significantly reduced possible overall height of the micromechanical sensor device 100, without having to make changes to the thickness of the wafer stacks of the first and second MEMS component 10, 20.

In the 4 illustrated embodiment of the micromechanical sensor device 100 also represents a compared to the arrangement of 2 further developed embodiment in which part of the surface of the second MEMS component 20 is molded over and part of the surface of the second MEMS component 20 remains free of molding compound. Such arrangements can be technically realized, for example, by so-called "film-assisted molding". Alternatively, the surface of the micromechanical sensor device 100 could first be completely overmoulded, with molding compound only being removed at defined points on the upper side of the sensor device 100 afterwards.

Based on the configuration in 2 the second MEMS component 20 can be constructed inverted, so that the functional side of the MEMS chip 20b is on the outside and is oriented upwards. For example, a membrane 27 for a pressure sensor or for a microphone, or more generally a media access for a sensor, can be arranged on the upper side of the second MEMS component 20 . In this case, the MEMS signals are routed to the ASIC chip 20a of the second MEMS component 20 via MEMS vias 22 .
Likewise, electrical ASIC signals of the second MEMS component 20 are routed via MEMS vias 22 to the rewiring level on the surface of the second MEMS component 20 and from there by means of a vertical 3D rewiring element 23a to the top of the first MEMS component 10 . It should be pointed out that the representation with the membrane 27 lying on the outside is only to be understood as an example. It is also possible for the membrane area to be arranged on the inner side of the MEMS chip 20b, ie facing the ASIC chip 20a. In this case, media access must be implemented through the MEMS substrate, eg via deep trenches.

In the configuration of 4 a 7D sensor (IMU plus pressure sensor) or even a 10D sensor (IMU+magnetic sensor plus pressure sensor) could be implemented in a very compact manner by combining a pressure sensor with an IMU and, if necessary, a three-axis magnetic sensor. Such sensor combinations can be used well for navigation purposes or for navigation support if, for example, there is temporarily no GNSS signal for locating via satellite, as may be the case in buildings, tunnels, urban canyons and the like.

The 5 until 10 show in comparison to the previously explained arrangements of 2-4 a fundamentally changed topology of the proposed micromechanical sensor device 100.

In 5 is compared to 2 the first MEMS component 10 is arranged inverted, ie aligned with the MEMS chip 10b downwards. Instead of flip-chip assembly with solder balls, the MEMS chip 10b is bonded to the substrate 1 with a second adhesive layer 60, preferably by means of a die-attach film. The electrical sensor signals are routed to a rewiring level 28 via ASIC vias 12 in the ASIC chip 10a that is now on top. The rewiring level 28 also serves (analogously to the previous exemplary embodiments) to provide bonding pads for the bonding wires 25 from the surface of the first MEMS component 10 to the substrate 1 . A passivation layer 29 serves to protect the rewiring and electrical insulation before the second MEMS component 20 is applied. Depending on the type of application of the second MEMS component 20, the first adhesive layer 40 used (e.g. die-attach film, soft silicone adhesive ) fulfill this function. One recognizes in 5 that bonding wires 25 for electrical contacting of the substrate 1 are contacted both with the 3D rewiring element 23 and with the rewiring level 28 .

Since the thickness of the second adhesive layer 60 is generally significantly less than typical standoffs after flip-chip assembly (adhesive layer in die-attach films typically approx. 10 µm... approx. 20 µm, standoff after flip-chip, on the other hand, tends to larger than 50 µm), this arrangement can be compared to the arrangement of 2 a further significant reduction in overall height of the micromechanical sensor device 100 can be achieved. As a further advantage, this arrangement does not require a rewiring level on both sides of the first MEMS component 10, but only on the ASIC rear side, as a result of which the process complexity and the manufacturing costs can be reduced.

A further reduction in the achievable height results from the arrangement of 6 , at which, starting from the arrangement of 5 (and analogous to the arrangement of 3 ) overmolding of the second MEMS component 20 is dispensed with. It can be seen that the entire area above the second MEMS component 20 is saved, ie the sum of the height of the wire bond loop plus the height of the mold cover, which can typically correspond to a saving of approximately 150 μm.

7 10 with reference to the arrangement of FIG 4 the possibility of partial mold coverage. This application is advantageous for Sen sensors that require media access or have a corresponding membrane 27, such as pressure sensors, microphones and the like. Compared to the flip-chip mounting arrangement of the first MEMS device 10 of FIG 4 results in a reduction in component height for the arrangement shown. This is in the range of the typical standoff after flip-chip assembly of more than 50 μm minus the thickness of the second adhesive layer 60 of approximately 10 μm to approximately 20 μm.

The arrangements of 8-10 show a possibility of further reducing the footprint, ie the required base area of the component during assembly on the substrate 1. For this purpose, electrical connections from the surface of the first MEMS component 10 to the substrate 1 are also implemented via a 3D rewiring element 23b. The electrical connection of the second MEMS component 20 is also routed via the rewiring on the first MEMS component 10 to the further vertical rewiring from the first MEMs component 10 to the substrate 1 .

The arrangements of 9 and 10 12 show cross-sectional views of variants in which the micromechanical sensor devices 100, open at the top, manage entirely without wire bonds and electrical contact is made with the substrate 1 exclusively with 3D rewiring elements 23a, 23b. The arrangement of 9 has opposite the arrangement of 8th no molding compound on the upper side, so that the overall height of the sensor device 100 is further reduced.

Compared to the arrangements of 5-7 the wire bond connections shown there and the corresponding provision for them on the substrate 1 are no longer required, resulting in a reduction in the lateral footprint. Depending on the design of the wire bonding, the reduction affects at least one side.

The proposed arrangements are in no way limited to mold housings. Rather, instead of a mold housing, a so-called open cavity housing with a metal cover or a mold cap can be used on the substrate 1, as is the case, for. Am 11 is shown. As the housing designation already indicates, such a housing 50 has an open cavern or a free volume 51 .

Compared to the arrangement of 8th is in the arrangement of 11 the second adhesive layer 60 is also made thicker in a defined manner. The second adhesive layer 60 can preferably be a particularly soft and thick adhesive, e.g. B. act a silicone-like adhesive. Since the second adhesive layer 60 then transfers hardly any mechanical stress from the substrate 1 and the two MEMS components 10, 20 are not exposed to any stress transfer laterally or from above, this arrangement is particularly suitable for very high demands on the stress robustness of the overall component, e.g. B. with very high demands on the stability of offset and sensitivity of sensors, whereby these measured variables are typically particularly affected by mechanical stress.

In addition to reduced stress transmission, an open cavity housing also enables simple implementation of media access. The arrangement of 12 shows the same membrane sensor as the second MEMS component 20 as an example 4 with a membrane 27 on top and MEMS vias 22 through the MEMS chip 20b. In this case, the open cavity housing contains an opening 52 at the top of the housing cap for media access, e.g. B. for a pressure sensor. Otherwise, the arrangement of 12 that of 10 .

An extension of the arrangement of 2 and following shows 13 , namely a triple stack with a first MEMS component 10, a second MEMS component 20 and a third MEMS component 30. The third MEMS component 30 is connected to the second MEMS component 20 by means of a third adhesive layer 70 (e.g. B. die-attach film) mechanically connected and electrically connected to the redistribution level of the second MEMS component 20 via a vertically running 3D redistribution element 23c. A vertically running 3D rewiring element 23a leads from the top of the second MEMS component 20 to the rewiring level of the first MEMS component 10 and from there via a vertical rewiring element 23b to the substrate 1.

It is understood that a basic idea of the arrangement of 13 can also be transferred to a fourth, fifth, etc. stacked MEMS device (not shown).

14 shows a combination of a total of four MEMS components 10, 20, 30, 40, each formed in an ASICap arrangement, with two MEMS components corresponding to the basic arrangement of 8th are stacked on top of each other and the two stacked pairs of MEMS components are then arranged side by side in a common housing 50, in this example in a molded housing. This overall configuration is advantageously with respect to the circuit board assembly space-saving than the assembly of two separate modules, each of which the arrangement of 8th are equivalent to.

15 shows a further arrangement of two stacked integrated MEMS ASIC components 10, 20, which in turn the arrangement of 2 has as a starting point. In this case, an ASIC and a MEMS chip are also arranged one on top of the other using a metallic wafer bonding method, but in this case the ASIC signals are routed to the outside via vias 22 through the MEMS chips 10b, 20b. The figure is intended to indicate in particular that the proposed arrangement is equally applicable to MEMS components both with ASIC vias 12 and with MEMS vias 22, and therefore also for a mixture of the two possibilities, e.g. B. First MEMS device 10 with ASIC vias 12 and second MEMS device 20 with MEMS vias 22.

The proposed sensor device 100 can be particularly advantageous, e.g. B. be used in the field of consumer electronics.

16 shows a basic sequence of a proposed method for producing a proposed micromechanical sensor device 100.

In a step 200, at least two MEMS components 10, 20 are provided, the MEMS components 10, 20 each being in the form of a stacked arrangement of a MEMS element 10b, 20b with an ASIC element 10a, 20a.

In a step 210, a second MEMS component 20 is arranged by means of a first adhesive layer 40 on a top side of a first MEMS component 10.

In a step 220, at least one of the MEMS components 10, 20 is electrically contacted by means of a 3D rewiring element 23a...23c, which extends at least partially over a vertical section of at least one of the MEMS components 10, 20, electrically to a Substrate 1 of the micromechanical sensor device 100.

Finally, in a step 230, the at least two MEMS components 10, 20 are at least partially enclosed by a housing 50.

In summary, a micromechanical sensor device and a method for its production are proposed, which is designed as a system-in-package as at least two ASICap components stacked on top of one another.

Although the invention has been described above on the basis of specific exemplary embodiments, the person skilled in the art can also implement embodiments that are not disclosed or only partially disclosed without departing from the core of the invention.

• Weckfunktionen für ausgewählte Gerätemodule, Erkennung von Geräteorientierung, Bildschirmorientierung und Anzeigeorientierung, Erkennung einer signifikanten Bewegung, Schock- und Freifallerkennung;
• HMI (Mensch-Maschine-Schnittstelle)-Funktionalität, z. B. Multi-Tap-Erkennung, Aktivitäts-, Gesten- und Kontexterkennung, Benutzererkennung; Bewegungssteuerung, Kardansystem, Höhen- und Lagestabilisierung, Flugsteuerung, Bildstabilisierung, Innen- und Außennavigation, Stockwerkserkennung, Positionsverfolgung und Streckenaufzeichnung , PDR (Fußgänger-Koppelnavigation), dynamische Streckenplanung, Erkennung von Begrenzungen und Hindernissen, Indoor-SLAM (Simultanlokalisierung und Kartenerstellung);
• Einbruchsüberwachung, Echtzeit-Bewegungserkennung und -verfolgung, Aktivitätsverfolgung, Schrittezähler, Kalorienzähler, Schlafüberwachung;
• Erfassung des Tragezustands von Hearables (in-ear detection), Bestimmung von Kopforientierung und Kopfbewegung;
• Logistik, Teilenachverfolgung, Energiemanagement und energiesparendes Messen, vorausschauende Wartung;
• Überwachung von Luftqualität und Klima, Schimmelerkennung, Wasserstandserkennung;
• Sensordatenfusion.

The invention can be used in connection with smartphones and tablets, wearables, hearables, AR (augmented reality) and VR (virtual reality), drones, gaming and toys, robots, smart homes and in an industrial context for the following applications, among others :

• Wake-up functions for selected device modules, detection of device orientation, screen orientation and display orientation, detection of significant movement, shock and free-fall detection;
• HMI (Human Machine Interface) functionality, e.g. B. Multi-tap detection, activity, gesture and context detection, user detection; Motion control, gimbals, altitude and attitude stabilization, flight control, image stabilization, indoor and outdoor navigation, floor detection, position tracking and route recording, PDR (pedestrian dead reckoning), dynamic route planning, boundary and obstacle detection, indoor SLAM (simultaneous localization and mapping);
• Intrusion monitoring, real-time motion detection and tracking, activity tracking, pedometer, calorie counter, sleep monitoring;
• Detection of the wearing status of hearables (in-ear detection), determination of head orientation and head movement;
• logistics, part tracking, energy management and energy saving metering, predictive maintenance;
• Air quality and climate monitoring, mold detection, water level detection;
• sensor data fusion.

QUOTES INCLUDED IN DESCRIPTION

This list of documents cited 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

• US20160362293A1 [0003]
• US2018254258A1 [0004]

Claims (13)

Micromechanical sensor device (100), comprising: - At least two MEMS components (10, 20), wherein the MEMS components (10, 20) are each formed as a stacked arrangement of a MEMS element (10b, 20b) with an ASIC element (10a, 20a); whereby - A second MEMS component (20) is arranged by means of a first adhesive layer (41) on a top side of a first MEMS component (10); whereby - the at least two MEMS components (10, 20) are at least partially enclosed by a housing (50); whereby - At least the second MEMS component (20) by means of a 3D rewiring element (23a ... 23c), which extends at least partially over a vertical section of the second MEMS component (20), electrically to a substrate (1) of the micromechanical Sensor device (100) and / or to the first MEMS component (10) is connected. Micromechanical sensor device (100) after claim 1 , characterized in that the first MEMS component (10) is electrically connected to the substrate (1) by means of at least one bonding wire (25). Micromechanical sensor device (100) after claim 1 or 2 , characterized in that a passivation element (26) is arranged at least in sections above the second MEMS component (20) on an upper side of the micromechanical sensor device (100). Micromechanical sensor device (100) according to one of the preceding claims, characterized in that above the second MEMS component (20) on an upper side of the micromechanical sensor device (100) the housing (50) is open at least in sections. Micromechanical sensor device (100) according to one of claims 2 until 4 , characterized in that the first MEMS component (10) is connected to the substrate (1) by means of flip-chip assembly or by means of a second adhesive layer (60). Micromechanical sensor device (100) according to one of the preceding claims, characterized in that all electrical contacts are realized by means of 3D rewiring elements (23a...23c). Micromechanical sensor device (100) according to one of the preceding claims, characterized in that the housing (50) is a molded housing or an open cavity housing. Micromechanical sensor device (100) after claim 7 , characterized in that on an upper side of the micromechanical sensor device (100) molding compound is removed, with a passivation element (26) being arranged at least in sections on the upper side of the micromechanical sensor device (100). Micromechanical sensor device (100) after claim 11 , characterized in that the mold housing is at least partially exposed on an upper side. Micromechanical sensor device (100) according to one of Claims 7 until 10 , characterized in that an opening (52) is formed in the open cavity housing at the top. Micromechanical sensor device (100) according to one of the preceding claims, characterized in that in at least one of the MEMS components (10, 20) there is a via in the ASIC chip (10a, 20a) and/or in the MEMS chip (10b, 20b) is trained. Micromechanical sensor device (100) according to one of the preceding claims, characterized in that the first and/or the second MEMS component (10, 20) have a pitch of the solder balls (11) which is smaller than a standard pitch. Method for producing a micromechanical sensor device (100), having the steps: - Providing at least two MEMS components (10, 20), wherein the MEMS components (10, 20) are each formed as a stacked arrangement of a MEMS element (10b, 20b) with an ASIC element (10a, 20a); - arranging a second MEMS component (20) by means of a first adhesive layer (40) on a top side of a first MEMS component (10); - Electrical contacting of at least one of the MEMS components (10, 20) by means of a 3D rewiring element (23), which extends at least partially over a vertical section of at least one of the MEMS components (10, 20), to a substrate (1) the micromechanical sensor device (100); and - At least partially enclosing the at least two MEMS components (10, 20) by a housing (50).

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