CN203929747U - Sensor module - Google Patents

Abstract

The utility model relates to a sensor assembly. A sensor assembly comprising: a sensor chip (2) with conductive structures and measuring elements (21) on the upper side (26) of the sensor chip (2); one or more sensor chips on the lower side of the sensor chip (2) The connection point (24) of (27), one or more electrical through-contact connections (23) passing through the sensor chip (2), is used to connect the conductive structure on the upper side (26) with one or more A connection site (24) on the lower side (27) is electrically connected; a cover device (3) in the form of a substrate mounted on the upper side (26) of the sensor chip (2); leads to the sensor in the cover device (3) Channels of the measuring element (21) of the chip (2). The sensor assembly has a cuboid shape. Such a sensor component can be arranged on the circuit carrier in a simple manner.

Description

sensor assembly

technical field

The utility model relates to a sensor assembly.

Background technique

Nowadays, sensor components usually comprise a sensor chip, on the substrate of which is arranged or integrated in the substrate the own sensor functionality in the form of a measurement-sensitive element. In this case, the substrate can be a semiconductor substrate, for example made of silicon, into which circuit functionality, such as, for example, an electronic evaluation circuit, is also integrated. An example of such a sensor chip is known from the assignee's European patent EP1236038B1.

Unprotected sensor chips can be damaged during further processing. The electrical connection structures of the sensor chip are also mostly not suitable for direct connection to a circuit carrier, for example a conventional circuit board.

Utility model content

The utility model relates to a sensor assembly. The sensor component comprises a sensor chip which has an electrically conductive structure and a measuring element on the upper side of the sensor chip. One or more connection points are provided on the underside of the sensor chip, which are connected to conductive structures on the upper side of the sensor chip via one or more electrical through-contact connections passing through the sensor chip. A cover in the form of a substrate is mounted on the upper side of the sensor chip, said cover having a channel leading to the measuring element of the sensor chip. The sensor module is cuboid-shaped.

The sensor assembly comprises: a sensor chip with conductive structures and measuring elements on the upper side of the sensor chip; one or more connection points on the lower side of the sensor chip; one or more electrical through-throughs through the sensor chip Contact connection for electrically connecting the conductive structure on the upper side to the one or more connection points on the lower side; a cover device in the form of a substrate mounted on the upper side of the sensor chip; in the cover device Channel to the measuring element of the sensor chip. The sensor assembly has a cuboid shape.

Such a sensor component can be arranged in a simple manner on a circuit carrier which, for example, has metallized regions as counterparts to the connection points of the sensor chip. In this case, the region on the circuit carrier side is connected to the connection points of the sensor component via electrically conductive means, for example solder paste or solder balls. Due to the through-contact connections, the connection points for the sensor assembly are then placed on the rear side of the sensor chip, so that no bonding wires and no potting for such bonding wires are required, and the sensor assembly nonetheless comes in the form of Its upper side with the measuring element faces the surroundings and not, as in the case of flip-chip technology, toward the circuit carrier.

The geometry of the connection points on the underside of the sensor assembly is advantageous for obtaining a compact design with small dimensions and at the same time allows good electrical decoupling of the connection points from one another. Furthermore, the preferably central passage leading to the upper side of the sensor package enables the shortest possible connection from the surroundings of the sensor package to the measuring element of the sensor chip. An extremely compact, insensitive sensor assembly is also achieved, which is protected from damage by the covering device during its further processing. In an advantageous further development, optical or mechanical positioning aids can be provided in order to support the correct positioning of the sensor component when arranged on the circuit carrier.

Preferably, the sensor component has a length that is greater than its width, so that the sensor component has a rectangular base area. In this case, the channel in the covering device can advantageously be arranged in the intersection of the diagonals of the rectangle formed by the length and width, that is to say centrally. Preferably, the sensor assembly is shorter than 1.5mm and narrower than 1mm. Preferably said sensor assembly is also shorter than 0.7mm.

Preferably, at least four connection locations are provided on the underside of the sensor chip, wherein each quarter of the underside of the sensor chip has at least one connection location. This enables the best possible surface utilization. Preferably, at least four through-contact connections are also provided, wherein each quarter of the underside of the sensor chip has at least one through-contact connection, and in an advantageous further development The through-contact connection ends close to the associated connection point, preferably at a distance of less than 0.2 mm, so that the connection between the end of the through-contact connection and the connection point is dimensioned as short as possible . Preferably, a one-to-one arrangement of through-contact connections to connection locations is provided, ie each through-contact connection is connected to exactly one unique connection location. In this regard, in an advantageous refinement, the number of through-contact connections corresponds to the number of connection points.

Preferably, the channel is formed as an opening in the cover, and the opening extends cylindrically above the measuring element through the cover.

Preferably, the cross-section of the opening is larger than the cross-section of the measuring element.

Preferably, the sensor assembly has a length greater than its width, and the channel is provided in the intersection of the diagonals of the rectangle formed by the length and width.

Preferably, the sensor assembly has a length of less than 1.5 mm and a width of less than 1 mm.

Preferably, the sensor assembly has a height of less than 0.7mm.

Preferably, an adhesive layer is provided between the sensor chip and the cover device.

Preferably, a protective layer is provided between the sensor chip and the covering device.

Preferably, a protective layer is provided between the sensor chip and the cover device, said protective layer being arranged between the sensor chip and the adhesive layer.

Preferably, the measuring element is not covered by a protective layer, and the protective layer surrounds and is spaced from the measuring element.

Preferably, the measuring element protrudes from the remaining surface of the sensor chip and forms a groove between the measuring element and a protective layer surrounding the measuring element.

Preferably, the sensor chip comprises a silicon substrate into which the electronic circuit is integrated and the electronic circuit and/or the measuring element are electrically connected to one or more through-contact connections via conductive structures.

Preferably, said covering means comprises a silicon substrate.

Preferably, each connection point is assigned a conductive element.

Preferably, at least four connection points are provided, wherein each lower quarter of the sensor chip has at least one connection point.

Preferably, at least four through-contact connections are provided, wherein each quarter of the underside of the sensor chip has at least one through-contact connection.

Preferably, the number of through-contact connections corresponds to the number of connection locations.

Preferably, each through-contact connection is electrically conductively connected to exactly one connection location.

Preferably, six connection locations are provided, wherein the connection locations are arranged in two rows of three next to each other along the longitudinal extension of the underside of the sensor chip.

Preferably, exactly four through-contact connections are provided, wherein each quarter of the underside of the sensor chip has at least one through-contact connection.

Preferably, electrically conductive structures are provided on the underside of the sensor chip for electrically connecting the through-contact connections to the connection points.

Preferably, the electrically conductive structures on the underside of the sensor chip are coated with varnish.

Preferably, the cuboid-shaped sensor assembly has four flat side walls, and at least a part of the cover means and a part of the sensor chip are exposed on each side wall.

Preferably, the sensor assembly is a humidity sensor.

Description of drawings

Further configurations, advantages and applications of the invention emerge from the subclaims and from the following description with reference to the drawings. In the picture:

1 shows a perspective view of a sensor assembly according to an embodiment of the present invention with FIG. 1a), its upper side view with FIG. 1b), its lower side view with FIG. 1c), and FIG. 1d ) shows its longitudinal sectional view and with FIG. 1 e) its transverse sectional view, and

Figure 2 shows a perspective view of a sensor assembly according to another embodiment of the present invention with Figure 2a), its upper side view with Figure 2b), and its lower side view with Figure 2c) with Figure 2c). 2d) shows its longitudinal section and FIG. 2e) its transverse section.

Detailed ways

Identical elements are generally indicated by the same reference numerals in the figures.

FIG. la) shows a perspective view of a sensor assembly 1 according to an embodiment of the invention, viewed from its upper side. The sensor assembly 1 basically has a cuboid shape. The sensor component 1 comprises a cover device 3 which is connected to a sensor chip 2 via an adhesive layer 4 . In the exemplary embodiment, the cover device 3 is a substrate and in particular a semiconductor substrate, for example a silicon substrate, which serves to protect the sensor chip 2 . Preferably, the cover device 3 covers the entire surface of the sensor chip 2 except for the region in which the measuring element on the upper side of the sensor chip is arranged. This region is accessible via a channel in the cover 3 , which is formed in the present example as a cylindrical opening 31 in the cover 3 and which is arranged directly above the measuring element, so that The measuring element has access to the environment through the opening 31 and can in particular measure parameters of the surroundings of the sensor assembly. The measuring element can be, for example, a measuring layer which, in the case of a humidity sensor, is preferably formed as a polymer layer or a ceramic layer and which can absorb water molecules from the environment of the sensor component. In this context, it is preferred that the measuring element is connected to the surroundings of the sensor assembly via channels in the cover device 3 , so that a fluid surrounding the sensor assembly, for example a gas or a liquid, can reach this surface part of the sensor chip 2 . In the present example, the opening 31 has a circular cross section and a cylindrical shape, but in another embodiment it can also taper, for example, in the direction of the sensor chip 2 , that is to say have a conical shape. . Such recesses can be produced beforehand into the base of the cover device 3 . The sensor chip 2 and the cover 3 are exposed on the side 7 of the sensor assembly.

FIG. 1 b ) shows a plan view of the upper side of the sensor assembly according to FIG. 1 a ). Here, in particular, the cover device 3 with the central opening 31 can then be seen. When the length L of the sensor assembly 1 is greater than the width B, the opening 31 is arranged centrally at the intersection of the diagonals of the rectangle thus defined. Here, for example, the length L=1.31 mm and the width B=0.74 mm. The opening 31 allows a view into the circular measuring element 21 in this embodiment, which can be a sensitive layer, for example. The likewise circular opening 31 in the cover has a larger diameter than the measuring element 21 , so that the cover 3 surrounds the measuring element 21 , but keeps a distance between the measuring element 21 and the covering 3 . The substrate 22 of the sensor chip 2 or the layer covering the substrate 22 is exposed in this intermediate space.

FIG. 1 d ) shows a longitudinal sectional view of the sensor assembly according to FIG. 1 a ) along the vertical dashed line in FIG. 1 b ). It can be seen here that the cover device 3 , including its opening 31 , is arranged above the measuring element 21 and enables access to this measuring element. The cover device 3 is glued to the sensor chip 2 and in particular to its upper side 26 by means of an adhesive layer 4 . In this case, the measuring cell 21 is not covered by the adhesive layer 4 in order not to hinder its measuring performance. Measuring element 21 is therefore also mounted on top side 26 of sensor chip 2 , on which top side 26 also has electrically conductive structures. Since the sensor chip 2 is preferably a semiconductor substrate, for example a silicon substrate, into which electronic circuits 28 are preferably also integrated for preprocessing and/or analyzing the signals of the measuring element 21, conductive structures not explicitly marked in the figure This can be realized, for example, by means of metal layers of a CMOS (Complementary Metal Oxide Semiconductor) process, which is also used to produce the circuit 28 integrated into the upper side 26 of the sensor chip 2 . The integrated circuit 28 can be integrated into the semiconductor substrate at the point where the circuit is protected by the light-tight cover 3 . The conductive structure can electrically connect the measuring element 21 to the integrated circuit 28 and can also connect the integrated circuit 28 and/or the measuring element 21 to through contacts between the upper side 26 of the sensor chip 2 and its lower side 27 Part 23 is electrically connected. Two such exemplary through-contact connections 23 are shown in FIG. 1 d ). The electrical connection of the sensor assembly therefore does not have to be made on the upper side 26 of the sensor chip 2, so that bonding wires ( ). Alternatively, the underside 27 of the sensor chip 2 is provided with electrically conductive connection points 24 , which in turn are connected via electrically conductive connections 25 to through-contact connections 23 , see top view of the underside 27 in FIG. 1 c ). Each connection site preferably has a solder ball 5, through which the sensor assembly can then be connected to the circuit carrier ( ) are electrically and mechanically connected. The electrically conductive connections 25 and other electrically conductive structures on the underside 27 of the sensor chip 2 are preferably coated with varnish for protection, but at least the solder balls 5 are freed. In the present example, six connection locations 24 are provided, each in a row of three along the longitudinal extension of the sensor assembly. Four through-contact connections 23 are visible in the corners of sensor chip 2 , which are each electrically connected to an associated connection point 24 via short conductive connections 25 . Two of the connection points 24 are provided in the present case for supplying electrical energy to the sensor assembly, while the other two of the connection points 24 transmit signals from/to the integrated circuit 28 and/or the measuring element 21 .

1d), the height H of the sensor assembly without solder balls 5 is preferably 0.425 mm, wherein the height H3 of the covering device 3 is about 0.3 mm and the height of the sensor chip is about 0.1 mm. The diameter D of the opening 31 may be approximately 0.30mm, or preferably between 0.25mm and 0.55mm. The adhesive layer 4 likewise has approximately circular cutouts. The diameter of this cutout in the region of the opening 31 is preferably greater than the diameter D of the opening 31 , for example 0.31 mm for the aforementioned diameter D of 0.30 mm of the opening, as schematically depicted in FIG. 1 d ). The distance between adjacent solder balls 5 (center point to center point) is preferably 0.4 mm.

Preferably, a plurality of sensor assemblies are produced simultaneously in a common production process. For this purpose, the semiconductor wafer for the sensor assembly can be connected, for example glued, to the cover wafer, and finally the wafer system thus connected can be separated into individual sensor assemblies by sawing, whereby the side walls 7 of the individual sensor assemblies are exposed in each case. Covering device 3 and sensor chip 2, see FIG. la).

2 shows a perspective view of a sensor assembly according to another embodiment of the present invention with FIG. 2 a), its upper side view with FIG. 2 b), and its lower side view with FIG. 2 c). 2d) shows its longitudinal section and FIG. 2e) its transverse section. The sensor assembly in FIG. 2 differs from the sensor assembly according to FIG. 1 only in that a protective layer 6 is provided between the cover device 3 and the sensor chip 2 . This protective layer 6 serves to protect the sensor chip 2 when the cover device 3 is bonded to the sensor chip 2 . The protective layer 6 can be, for example, an applied optically structurable varnish (dry resistant and preferably so constructed that the entire upper side 26 of the sensor chip 2 except for the measuring element 21 and the region surrounding the measuring element Cover with described varnish outside. Protective layer 6 therefore surrounds measuring element 21, and wherein, with the premise of circular structure, preferably the diameter of the void in protective layer 6 is greater than the diameter of measuring element 21. Preferably again in protective layer 6 The diameter of the vacancy is smaller than the diameter of the opening 31 in the cover device 3, so that in the top view of the upper side 26 of the sensor assembly according to FIG. 2b), the ring of the protective layer 6 can be seen through the opening 31 in the cover device 3 . This has the advantage that excess adhesive does not spread directly onto the measuring element 21 when the cover device 3 is bonded to the sensor chip 2 provided with the protective layer 6 . If the diffusion of the adhesive cannot stop itself, the diffusion stops at the edge of the protective layer 6 descending toward the semiconductor substrate at the latest due to the surface tension in the adhesive. If the adhesive nevertheless flows onto the substrate 22 , the adhesive is retained by capillary forces between the vertically rising edge of the protective layer 6 and the horizontal substrate 22 . The adhesive layer is not shown in FIG. 2 for reasons of clarity, but is arranged between cover 3 and protective layer 6 in order to bring about a non-detachable connection between cover 3 and sensor chip 2 .

Preferred embodiments of the invention are described in the present application, but it is expressly pointed out that the invention is not restricted thereto but may also be implemented in other ways within the scope of the following claims.

Claims (24)

1. sensor assembly, is characterized in that, described sensor assembly comprises: - a sensor chip (2) having a conductive structure and a measuring element (21) on the upper side (26) of the sensor chip (2), - one or more connection sites (24) on the underside (27) of the sensor chip (2), - one or more electrical through-contact connections (23) through the sensor chip (2) for connecting the conductive structures on the upper side (26) to the one or more on the lower side (27) The connection part (24) is electrically connected, - a covering device (3) in the form of a substrate mounted to the upper side (26) of the sensor chip (2), - access to the measuring element (21) of the sensor chip (2) in the covering device (3), The sensor assembly has a cuboid shape. 2. The sensor assembly according to claim 1, characterized in that the channel is formed as an opening (31) in the cover device (3), and the opening (31) is cylindrically above the measuring element (21) Extends through the cover (3). 3. The sensor assembly as claimed in claim 2, characterized in that the cross section of the opening (31) is larger than the cross section of the measuring element (21). 4. The sensor assembly according to claim 1, characterized in that the sensor assembly has a length (L) greater than its width (B), and the channel is arranged at a distance formed by the length (L) and width (B). At the intersection of the diagonals of the rectangle. 5. The sensor assembly according to claim 1, characterized in that the sensor assembly has a length (L) of less than 1.5 mm and a width (B) of less than 1 mm. 6. The sensor assembly according to claim 1, characterized in that the sensor assembly has a height (H) of less than 0.7 mm. 7. The sensor assembly as claimed in claim 1, characterized in that an adhesive layer (4) is provided between the sensor chip (2) and the cover device (3). 8. The sensor assembly as claimed in claim 1, characterized in that a protective layer (6) is provided between the sensor chip (2) and the cover device (3). 9. The sensor assembly according to claim 7, characterized in that a protective layer (6) is provided between the sensor chip (2) and the covering device (3), the protective layer (6) being arranged on the sensor chip (2) and the adhesive layer (4). 10. The sensor assembly according to claim 8 or claim 9, characterized in that the measuring element (21) is not covered by the protective layer (6) and that the protective layer (6) surrounds the measuring element (21 ) and spaced from the measuring element. 11. The sensor assembly according to claim 10, characterized in that the measuring element (21) protrudes from the remaining surface of the sensor chip (2) and extends between the measuring element (21) and surrounding the measuring element (21). ) between the protective layers (6) to form a groove. 12. The sensor assembly according to claim 1, characterized in that the sensor chip (2) comprises a silicon substrate, into which the electronic circuit (28) is integrated, and the electronic circuit (28) and/or the measurement The element (21) is electrically connected to the one or more through-contact connections (23) via a conductive structure. 13. The sensor assembly according to claim 1, characterized in that the covering device (3) comprises a silicon substrate. 14. The sensor assembly as claimed in claim 1, characterized in that each connection point (24) is assigned a conductive element. 15. The sensor assembly according to claim 1, characterized in that at least four connection locations (24) are provided, wherein each quarter of the underside (27) of the sensor chip (2) has At least one connection site (24). 16. The sensor assembly according to claim 1, characterized in that at least four through-contact connections (23) are provided, wherein each quarter of the underside (27) of the sensor chip (2) The part has at least one through-contact connection (23). 17. The sensor assembly according to claim 1, characterized in that the number of through-contact connections (23) corresponds to the number of connection points (24). 18. The sensor assembly according to claim 1, characterized in that each through-contact connection (23) is electrically conductively connected to exactly one connection location (24). 19. The sensor assembly according to claim 1, characterized in that six connection locations (24) are provided, wherein the connection locations (24) are arranged side by side in two rows of three along the sensor chip (2) The longitudinal extension of the lower side (27) is provided. 20. The sensor assembly according to claim 1, characterized in that exactly four through-contact connections (23) are provided, wherein each quarter of the underside (27) of the sensor chip (2) The part has at least one through-contact connection (23). 21. The sensor assembly according to claim 1, characterized in that an electrically conductive structure (25) is provided on the underside (27) of the sensor chip (2) for connecting the through-contact connection (23) to the The connecting portion (24) is electrically connected. 22. The sensor assembly as claimed in claim 21, characterized in that the electrically conductive structures (25) on the underside (27) of the sensor chip (2) are coated with varnish. 23. The sensor assembly according to claim 1, characterized in that the cuboid sensor assembly has four flat side walls (7), and at least one part of the covering device (3) is exposed on each side wall (7). One part and one part of the sensor chip (2). 24. The sensor assembly of claim 1, wherein the sensor assembly is a humidity sensor.