TWI676250B - Optical sensor - Google Patents

Abstract

The invention discloses an optical sensor, which includes a substrate, a redistributed wafer structure disposed on the substrate, a sensing wafer disposed on the redistributed wafer structure, a light-transmitting sheet located above the sensing wafer, and an electrical connection substrate and a sensor. A plurality of metal lines of the wafer are measured, and a package body disposed on the substrate. The redistributed wafer structure includes an insulator, a first electronic chip buried in the insulator, and a reset circuit connected between the insulator and the bottom of the first electronic chip. The reset circuit is electrically connected to the first electronic chip and fixed to the substrate through a flip chip. The projection area formed by the sensing area of the sensing chip facing the redistribution wafer structure is located within the outer contour of the redistribution wafer structure. The redistribution-type wafer structure, the sensing wafer, a part of the light-transmitting sheet, and the metal wire are buried in the package body.

Description

Optical sensor

The invention relates to a sensor, in particular to an optical sensor.

The existing optical sensor includes a state in which a large-sized wafer is stacked over a small-sized wafer, and the periphery of the large-sized wafer of the existing optical sensor is electrically connected to the substrate by wire bonding. However, during the above-mentioned bonding process of the existing optical sensor, since the periphery of the large-sized wafer is suspended, the external force applied to the periphery of the large-sized wafer by the bonding process is likely to cause defects.

Therefore, the present inventor believes that the above-mentioned defects can be improved, and with special research and cooperation with the application of scientific principles, he finally proposes an invention with a reasonable design and effective improvement of the above-mentioned defects.

An embodiment of the present invention is to provide an optical sensor, which can effectively improve defects that may occur in the existing optical sensors.

An embodiment of the present invention discloses an optical sensor, including: a substrate; a heavy-duty wafer structure including an insulator, a first electronic chip embedded in the insulator, and a bottom connected to the insulator and the first electronic chip. A reset circuit; wherein the reset circuit is electrically connected to the first electronic chip, and the redistribution-type wafer structure is fixed to the substrate by flip chip resetting; a sensing chip having a size larger than the first chip; The size of an electronic chip, and the sensing chip is disposed on the redistributed wafer structure; wherein a bread of the sensing chip includes a sensing region, and the sensing region faces the redistributed wafer structure; A projection area formed by the projection is located at the re-layout Within the outer contour of the wafer structure; a light-transmitting sheet located above the sensing wafer; a plurality of metal wires electrically connecting the substrate and the sensing wafer; and a package disposed on the substrate, and The redistribution-type wafer structure, the sensing chip, and the metal wires are embedded in the package body; wherein the package body fixes the light transmitting sheet above the sensing chip and exposes a part of the surface of the light transmitting sheet .

In summary, the optical sensor disclosed in the embodiment of the present invention embeds the first electronic chip in the insulator of the redistributed wafer structure, and makes the redistributed wafer structure and the sensing wafer There is a specific configuration relationship between them (for example, the projection area formed by the sensing area being orthographically projected toward the redistributed wafer structure is located within the outer contour of the redistributed wafer structure), so the redistributed wafer structure can The sensor chip is effectively supported, thereby effectively resisting the external force applied to the sensor chip and avoiding defects during the wire bonding process of the sensor chip.

In order to further understand the features and technical contents of the present invention, please refer to the following detailed description and drawings of the present invention, but these descriptions and drawings are only used to illustrate the present invention, and not to make any limitation to the scope of the present invention limit.

100‧‧‧optical sensor

1‧‧‧ substrate

11‧‧‧Chip fixed area

12‧‧‧The first pad

13‧‧‧The third pad

2‧‧‧ Heavy cloth chip structure

21‧‧‧ insulator

211‧‧‧side edge

212‧‧‧ extension

213‧‧‧bearing department

22‧‧‧The first electronic chip

221‧‧‧Contact

23‧‧‧Reset line

231‧‧‧New contacts

24‧‧‧Solder Ball

25‧‧‧Second electronic chip

3‧‧‧ sensor chip

31‧‧‧Top

311‧‧‧sensor area

312‧‧‧Second pad

313‧‧‧Unwired area

32‧‧‧ underside

33‧‧‧Side edge

4‧‧‧Translucent sheet

5‧‧‧ metal wire

5a‧‧‧Wire

6‧‧‧ Package

61‧‧‧ support

62‧‧‧ Underfill

63‧‧‧ Cover

64‧‧‧ molded body

65‧‧‧ extension

7‧‧‧Third electronic chip

Da, Db‧‧‧ distance

S‧‧‧Sealed space

FIG. 1 is a schematic cross-sectional view of an optical sensor according to a first embodiment of the present invention.

FIG. 2 is a partially enlarged schematic diagram of a part II in FIG. 1.

3 is a schematic cross-sectional view of another aspect of the optical sensor according to the first embodiment of the present invention.

4 is a schematic cross-sectional view of an optical sensor according to a second embodiment of the present invention.

Please refer to FIGS. 1 to 4, which are embodiments of the present invention. It should be noted that this embodiment corresponds to the related quantities and appearances mentioned in the drawings, and is only used to specifically describe the embodiments of the present invention. In order to facilitate understanding of the content of the present invention, it is not intended to limit the protection scope of the present invention.

[Example 1]

Please refer to FIG. 1 to FIG. 3, which is a first embodiment of the present invention. As shown in FIG. 1 and FIG. 2, this embodiment discloses an optical sensor 100 including a substrate 1, a redistributed wafer structure 2 disposed on the substrate 1, and a sensor disposed on the redistributed wafer structure 2. The test chip 3, a light-transmitting sheet 4 located above the sensor chip 3, a plurality of metal wires 5 electrically connecting the substrate 1 and the sensor chip 3, and a package 6 disposed on the substrate 1.

It should be clarified that, in order to facilitate the description of the optical sensor 100 in this embodiment, the drawing is shown in a cross-sectional view, but it can be understood that corresponding parts of the optical sensor 100 not shown in the drawing may also be formed The construction. For example, FIG. 1 shows only two metal wires 5, but other metal wires 5 are also included in the part of the optical sensor 100 not shown in FIG. 1. The following will describe the structure and connection relationship of each element of the optical sensor 100 in this embodiment.

The substrate 1 is square or rectangular in this embodiment, and the substrate 1 is provided with a wafer fixing area 11 at a substantially center of a top surface thereof, and a plurality of first pads are provided on an outer part of the wafer fixing area 11. 12. In addition, the substrate 1 may further be provided with a plurality of solder balls (not labeled) on the bottom surface, which are soldered and fixed to an electronic component (not shown, such as a printed circuit board) through the solder balls of the substrate 1. In this way, the optical sensor 100 can be electrically connected to the electronic component.

The redistributed wafer structure 2 includes an insulator 21, a first electronic chip 22 embedded in the insulator 21, and a reset line 23 (redistribution layer, RDL) connected between the insulator 21 and the bottom of the first electronic chip 22. ), And a plurality of solder balls 24. The first electronic chip 22 is described with an image signal processor in this embodiment, but is not limited thereto.

Furthermore, in this embodiment, the insulator 21 is covered by molding. It surrounds the first electronic chip 22, and the top surface and the bottom surface of the insulator 21 are respectively aligned with the top surface and the bottom surface of the first electronic chip 22. The reset circuit 23 is formed on a bottom surface of the insulator 21 and a bottom surface of the first electronic chip 22, and the reset circuit 23 is electrically connected to the first electronic chip 22. Wherein, the plurality of contacts 221 located at the bottom of the first electronic chip 22 may be connected to the plurality of new contacts 231 located at the bottom of the redistribution-type wafer structure 2 and having a larger pitch through the reset circuit 23. That is, the reset circuit 23 is equivalent to a circuit fan-out structure. In addition, the reset circuit 23 located below the insulator 21 is preferably provided with at least part of the new contacts 231, but the present invention is not limited thereto.

Furthermore, the redistributed wafer structure 2 is flip-chip-fixed to the substrate 1 (wafer-fixing region 11) through the reset circuit 23. In this embodiment, the reset circuit 23 is soldered to the wafer fixing area 11 of the substrate 1 through the solder balls 24 (the soldering in this embodiment includes a structural and electrical connection).

The sensing chip 3 is described with an image sensing chip in this embodiment, but is not limited thereto. Wherein, the sensing chip 3 includes a top surface 31 and a bottom surface 32 on opposite sides, and the sensing chip 3 is provided with a sensing area 311 at approximately the center of the top surface 31 thereof. A plurality of second pads 312 are provided on the outer part of the area 311, and the positions and numbers of the second pads 312 correspond to the positions and numbers of the first pads 12.

Furthermore, the sensing wafer 3 has a size larger than that of the first electronic wafer 22, and the sensing wafer 3 is disposed on the redistributed wafer structure 2; for example, a bottom surface 32 of the sensing wafer 3 is provided with an adhesive layer ( (Not shown) is fixed on the top surface of the insulator 21 and the top surface of the first electronic chip 22. From another perspective, the sensing region 311 of the sensing chip 3 faces a projection area formed by the orthographic projection of the redistributed wafer structure 2, which is located on the outer contour of the redistributed wafer structure 2 (eg, FIG. 1). Within the side edge 211) of the insulator 21, and the projection area in this embodiment preferably covers the The first electronic wafer 22, but the present invention is not limited to this.

In more detail, at least a partial side edge 211 of the insulator 21 is relative to the adjacent side edge 33 of the sensing chip 3 (eg, the left edge 211 of the insulator 21 is opposite to the left edge 33 of the sensing chip 3 in FIG. 1). ) Protrudes a distance Da, and the distance Da is less than 1 mm, but the present invention is not limited thereto. For example, in other embodiments not shown in the present invention, each side edge 211 of the insulator 21 may protrude from the corresponding side edge 33 of the sensing chip 3 by the distance Da.

Furthermore, at least a partial side edge 211 of the insulator 21 is relative to the adjacent side edge 33 of the sensing chip 3 (eg, the right edge 211 of the insulator 21 is opposite to the right edge 33 of the sensing chip 3) The distance Db is reduced, and the distance Db is less than 1 mm, but the present invention is not limited thereto. For example, in other embodiments not shown in the present invention, each side edge 211 of the insulator 21 may be within a distance Db from the corresponding side edge 33 of the sensing chip 3.

One end of the metal wires 5 are respectively connected to the first pads 12 of the substrate 1, and the other ends of the metal wires 5 are respectively connected to the second pads 312 of the sensing chip 3. The substrate 1 and the sensing chip 3 can be electrically connected through the metal wires 5.

According to the above, since the first electronic chip 22 is buried in the insulator 21 of the redistributed wafer structure 2 in this embodiment, and the redistributed wafer structure 2 and the sensing wafer 3 There is a specific configuration relationship (for example, the projection area formed by the sensing area 311 facing the redistribution wafer structure 2 is located within the outer contour of the redistribution wafer structure 2), so the redistribution wafer structure 2 can effectively support the sensing wafer 3, so that during the wire bonding process of the sensing wafer 3, it can effectively resist the external force applied to the sensing wafer 3 and avoid causing defects.

Further, a distance Da, Db of 1 mm or less is formed between the side edge 211 of the insulator 21 and the adjacent side edge 33 of the sensing chip 3 to avoid An excessively long gap is formed between the sensing wafer 3 and the substrate 1, so that it is difficult for air bubbles to be generated between the sensing wafer 3 and the substrate 1.

Furthermore, in this embodiment, the redistributed wafer structure 2 is fixed to the wafer fixing area 11 of the substrate 1 in a flip-chip manner. That is, the redistributed wafer structure 2 is located on the first pads 12. Inside. According to this, because the redistributed wafer structure 2 of this embodiment does not use a wire bonding method, the cost can be effectively reduced, and a short circuit between the redistributed wafer structure 2 and the sensing wafer 3 located above it can be avoided. The problem.

In this embodiment, the transparent sheet 4 is described by using a transparent glass plate, but the present invention is not limited thereto. Wherein, the light-transmitting sheet 4 is disposed above the top surface 31 of the sensing chip 3 through a packaging body 6 (such as a support 61 included in the following packaging body 6), and the light-transmitting sheet 4 faces the sensing chip. 3, the sensing region 311, and the light-transmitting sheet 4, the support body 61, and the sensing wafer 3 are enclosed together to form a sealed space S.

Moreover, the size of the transparent sheet 4 in this embodiment is smaller than the size of the sensing wafer 3. Wherein, the light-transmitting sheet 4 is a projection area formed by orthographic projection of the top surface 31 of the sensing chip 3, which covers the sensing area 311 and is located within the outer contour of the sensing chip 3, but the present invention is not limited. herein.

The package body 6 is disposed on the substrate 1, and the redistribution wafer structure 2, the sensing chip 3, and the metal wires 5 are buried in the package body 6; and the package body 6 fixes the transparent substrate 6. The light sheet 4 is above the sensing wafer 3 and exposes a part of the surface of the light transmitting sheet 4 (eg, the top surface of the light transmitting sheet 4 in FIG. 1).

In more detail, the package body 6 is mainly composed of a covering body 63 and a molding compound 64. However, in this embodiment, the package body 6 includes a support body 61 (such as an adhesive material), an underfill epoxy 62, an overcoat body 63, and a molding compound 64. In other words, the support body 61 and the underfill material 62 can also be regarded as a part of the package body 6 Minute. Wherein, the support body 61 is sandwiched between the top surface 31 of the sensing chip 3 and the transparent sheet 4, and the support body 61 is located outside the sensing area 311 and inside the second pads 312. . The underfill 62 is filled in a gap between the redistributed wafer structure 2 and the substrate 1; that is, the solder balls 24 of the redistributed wafer structure 2 are buried in the underfill 62. Inside.

In addition, the covering body 63 is disposed on the substrate 1, and the redistributed wafer structure 2, the sensing wafer 3, and the support body 61 are embedded in the covering body 63, and the covering body 63 exposes part of the surface of the light transmitting sheet 4. That is, the covering body 63 surrounds the outer side of the underfill material 62, the redistribution wafer structure 2, the sensing wafer 3, the support body 61, and the transparent sheet 4. Furthermore, in this embodiment, each metal wire 5 is completely embedded in the covering body 63.

In addition, the covering body 63 in this embodiment is formed by curing a liquid compound, and the molding body 64 is molded on the top surface of the covering body 63, but the present invention is not limited thereto. herein. For example, in other embodiments not shown in the present invention, the package body 6 may also omit the molded body 64.

In addition, in FIG. 1 of the present embodiment, the package body 6 is described as including a support body 61, a cover body 63, and an underfill 62, but the present invention is not limited thereto. For example, as shown in another aspect of the optical sensor 100 shown in FIG. 3, the package body 6 may also omit the underfill 62, and the package body 6 is covered with the covering body 63 in the redistribution type. A gap between the wafer structure 2 and the substrate 1. Wherein, the covering body 63 is preferably formed by a molding method, so as to facilitate filling the gap between the redistributed wafer structure 2 and the substrate 1.

[Example 2]

Please refer to FIG. 4, which is a second embodiment of the present invention. This embodiment is similar to the first embodiment described above, so the same points of the two embodiments are not described again, and the differences between this embodiment and the first embodiment Mainly as follows: In this embodiment, the redistributed wafer structure 2 further includes a second electronic wafer 25. Wherein, the first electronic wafer 22 and the second electronic wafer 25 are buried in the insulator 21 at intervals, and the sensing area 311 of the sensing wafer 3 faces the rear projection of the redistributed wafer structure 2. A projection area preferably covers the first electronic chip 22 and the second electronic chip 25, but the present invention is not limited thereto. Furthermore, the reset circuit 23 is formed on the bottom surface of the insulator 21, the bottom surface of the first electronic chip 22, and the bottom surface of the second electronic chip 25, and the first electronic chip 22 and the second electronic chip Each of 25 is electrically connected to the reset line 23.

Further, the optical sensor 100 may further include a third electronic wafer 7 which is not embedded in the redistribution wafer structure 2, and the substrate 1 and the insulator 21 are formed corresponding to the third electronic wafer 7. It has the following structure.

The insulator 21 includes an extension portion 212 protruding from the sensing chip 3, and the substrate 1 is provided with a third pad 13 inside the first pads 12 and adjacent to the extension portion 212; That is, the third pad 13 is located between the first pads 12 and the extending portion 212, but the present invention is not limited thereto.

Furthermore, the third electronic chip 7 is disposed on the extension portion 212, and the third electronic chip 7 is electrically connected to the substrate 1 (the third pad 13) through a wire 5 a. The third electronic chip 7 is adjacent to the sensing chip 3, and the height of the third electronic chip 7 relative to the insulator 21 is preferably lower than the top surface 31 of the sensing chip 3 compared to the insulator 21. To avoid the signal of the third electronic chip 7 from interfering with the signal of the metal wire 5.

In addition, the top surface 31 of the sensing chip 3 may include a non-wired area 313 located outside the sensing area 311 and not in contact with the metal wires 5, and the insulator 21 and the package body 6 should be non-wired. The region 313 is formed with the following structure.

The size of the light-transmitting sheet 4 is larger than the size of the sensing chip 3, and the size of the redistribution-type wafer structure 2 is larger than the size of the light-transmitting sheet 4. The insulator 21 includes A carrying portion 213 of the wiring area 313. Wherein the package The body 6 further includes an extension 65 disposed on the supporting portion 213 and adjacent to the non-wired region 313, and in this embodiment, the extension 65 is connected to the sensing chip 3 side adjacent to the non-wired region 313. The edge 33 (eg, the right edge 33 of the sensing chip 3 in FIG. 4), and the height of the extension body 65 relative to the insulator 21 is preferably equal to the height of the non-wired area 313 relative to the insulator 21.

In more detail, a part of the supporting body 61 is sandwiched between the top surface 31 of the sensing wafer 3 and the light transmitting sheet 4 (as shown on the left side of the sensing wafer 3 in FIG. 4), and the supporting body Another part of 61 is sandwiched between the transparent sheet 4 and the extended body 65 (as shown on the right side of the sensing wafer 3 in FIG. 4), and the support body 61 is embedded in the covering body 63. However, in other embodiments not shown in the present invention, the package body 6 may also omit the extension body 65; that is, the structure of the left and right sides of the sensing chip 3 in FIG. 4 is symmetrical, so the The supporting body 61 may be completely sandwiched between the top surface 31 of the sensing wafer 3 and the transparent sheet 4. According to the above, the support body 61 of the present invention may be at least partially sandwiched between the top surface 31 of the sensing wafer 3 and the transparent sheet 4.

Moreover, in this embodiment, a part of each metal wire 5 (and the second pad 312 connected to it) is buried in the supporting body 61, and another part of each metal wire 5 (and its phase) The connected first pads 12) are buried in the covering body 63, but the invention is not limited thereto.

In addition, in other embodiments not shown in the present invention, the optical sensor 100 of the first embodiment and the second embodiment may mutually replace the internal structure according to design requirements, for example, the optical sensor of the first embodiment 100 may be provided with the third electronic wafer 7, and the substrate 1 and the insulator 21 may have a structure as described in the second embodiment corresponding to the third electronic wafer 7.

[Technical effect of the embodiment of the present invention]

In summary, the optical sensor 100 disclosed in the embodiment of the present invention An electronic chip 22 is buried in the insulator 21 of the redistribution wafer structure 2, and a specific configuration relationship exists between the redistribution wafer structure 2 and the sensing wafer 3 (for example, the sensing area 311 faces The projection area formed by the orthographic projection of the redistribution wafer structure 2 is located within the outer contour of the redistribution wafer structure 2), so the redistribution wafer structure 2 can effectively support the sensing wafer 3, so that During the wire bonding process of the test chip 3, it effectively resists the external force applied to the test chip 3.

Furthermore, a distance Da, Db of 1 mm or less is formed between the side edge 211 of the insulator 21 and the adjacent side edge 33 of the sensing wafer 3, which can prevent the formation of excessive distance between the sensing wafer 3 and the substrate 1. The narrow gap makes it difficult for air bubbles to be generated between the sensing wafer 3 and the substrate 1.

The above description is only the preferred and feasible embodiments of the present invention, and is not intended to limit the protection scope of the present invention. Any equivalent changes and modifications made according to the patent scope of the present invention shall fall within the protection scope of the claims of the present invention.

Claims (10)

An optical sensor includes: a substrate; a redistributed wafer structure, including an insulator, a first electronic chip embedded in the insulator, and a reset circuit connected between the insulator and the bottom of the first electronic chip ; Wherein the reset circuit is electrically connected to the first electronic chip, and the redistribution chip structure is fixed to the substrate through the reset circuit flip chip, and the top surface and the bottom surface of the insulator are respectively aligned with the first A top surface and a bottom surface of the electronic chip; a sensing chip having a size larger than that of the first electronic chip, and the sensing chip is disposed on the redistributed wafer structure; wherein a top bread of the sensing chip contains a A sensing area, and a projection area formed by the orthographic projection of the sensing area toward the redistributed wafer structure is located within the outer contour of the redistributed wafer structure, and the bottom surface of the sensing wafer is fixed to the top of the insulator Surface and the top surface of the first electronic chip; a light-transmitting sheet located above the sensing chip; a plurality of metal wires electrically connecting the substrate and the sensing chip; and a package body disposed on the On the substrate, and the redistribution wafer structure, the sensing chip, and the metal wires are buried in the package body; wherein the package body fixes the light transmitting sheet above the sensing chip and exposes the light transmission Part of the surface of the sheet. The optical sensor according to claim 1, wherein the redistributed wafer structure includes a second electronic wafer, and the first electronic wafer and the second electronic wafer are buried in the insulator at intervals, and the first An electronic chip and the second electronic chip are each electrically connected to the reset circuit. The optical sensor according to claim 2, wherein the insulator includes an extension portion protruding from the sensing chip, and the optical sensor further includes a third electronic chip disposed on the extension portion. And the third electronic chip is electrically connected to the substrate by wire bonding. The optical sensor according to claim 1, wherein at least a partial side edge of the insulator protrudes a distance relative to an adjacent side edge of the sensing wafer, and the distance is less than 1 mm. The optical sensor according to claim 1, wherein at least a partial side edge of the insulator is retracted within a distance from an adjacent side edge of the sensing wafer, and the distance is less than 1 mm. The optical sensor according to claim 1, wherein the redistributed wafer structure includes a plurality of solder balls, and the reset circuit is soldered to the substrate through the solder balls; the package includes an underfill And the underfill agent is covered in a gap between the redistributed wafer structure and the substrate. The optical sensor according to claim 1, wherein the package includes: a support body, which is at least partially sandwiched between the top surface of the sensing chip and the transparent sheet; and a cover body Is disposed on the substrate; wherein the redistribution-type wafer structure, the sensing wafer, and the support are buried in the covering body, and the covering body exposes a part of the surface of the transparent sheet. The optical sensor according to claim 7, wherein a part of each of the metal wires is embedded in the support body, and another part of each of the metal wires is embedded in the cover body. The optical sensor according to claim 7, wherein the top bread of the sensing chip includes a non-wired area located outside the sensing area and not in contact with the metal wires, and the insulator includes a protrusion protruding from the wire. A carrying portion of the non-wired area of the sensing chip, the package further includes an extension disposed on the carrying portion and adjacent to the non-wired area; wherein a portion of the support is clamped by the Between the top surface and the light-transmitting sheet, another part of the support is sandwiched between the light-transmitting sheet and the extension, and the support is embedded in the covering body. The optical sensor according to claim 7, wherein the redistributed wafer structure includes a plurality of solder balls, the reset circuit is soldered to the substrate through the solder balls, and the cover is covered with A gap between the redistributed wafer structure and the substrate.