Anti-adhesive overflow cap for optical sensor package

Abstract

The present disclosure relates to an anti-glue overflow cap for an optical sensor package, wherein one or more embodiments relate to a system-in-package (SiP) for an optical device such as a proximity sensing or optical ranging device. One embodiment relates to an optical sensor package, the optical sensor package comprising a substrate, a sensor die coupled to the substrate, a light emitting device coupled to the substrate, and a cap. The cap is positioned around multiple side surfaces of the sensor die and covers at least a portion of the substrate. The cap comprises a first side wall and a second side wall, an inner wall having a first side surface and a second side surface and a mounting surface, and a cover member in contact with the first side wall, the second side wall and the inner wall. The first side surface and the second side surface are transverse to the mounting surface, and the inner wall comprises an opening extending from the mounting surface into the inner wall. A first adhesive material is disposed on the sensor die and at least partially within the opening, and the inner wall is fixed to the sensor die.

Description

Technical Field

[0001] Embodiments of the present disclosure relate to optical sensor packages, and more particularly to optical sensor packages having a cap that contains a liquid or otherwise prevents the escape of an adhesive material.

[0002] Related technologies

[0003] Optical sensors, such as proximity sensors, are used to detect the presence of nearby objects and are able to do so without physically contacting the object. Proximity sensors can be used in a variety of electronic devices, such as cameras, phones (including smartphones), vehicles, machines, and other devices that may want to detect the presence of nearby objects. After detecting the presence of a nearby object, the electronic device can be configured to perform functions such as moving a mechanical feature to a safe location, coupling or decoupling electrical communications, or any other desired function.

[0004] A proximity sensor typically includes a light emitting device such as a light emitting diode (LED) and a light receiving sensor such as a photodiode. The LED and the photodiode are packaged together in a sensor package. In general terms, the LED emits radiation through a first opening of the sensor package. If an object approaches the sensor package, an appropriate amount of the emitted radiation is reflected away from the object and back toward the sensor package. A portion of the reflected radiation enters a second opening in the sensor package near the photodiode. The photodiode receives the reflected radiation and generates an electrical signal indicative of the received radiation.

[0005] The sensor package is typically in electrical communication with an image sensor processor. The image sensor processor causes the LED to emit radiation and receives an electrical signal from a photodiode indicative of the received reflected radiation. Typically, the image sensor processor is enclosed in its own package, and both the sensor package and the image sensor processor package are coupled to a board (such as a circuit board) and are electrically coupled to each other through the board.

[0006] In addition, a cap is typically included in the proximity sensor package. The cap includes an opening for sending emitted radiation and an opening for receiving reflected radiation. A vent may be included in the cap for exhausting gases within the sensor package to the external environment from the inside, especially during heat treatment processes such as attaching the cap to the image sensor processor and board. The cap is attached to the substrate and image sensor processor by an adhesive material (such as glue). However, during the glue installation and / or curing process, glue overflow problems may occur, wherein the glue flows upward along the inner wall of the cap and may block the vent and further may cover the opening for emitting or receiving light. Summary of the invention

[0007] One or more embodiments relate to a system in package (SiP) for an optical device, such as a proximity sensing or ranging device. One embodiment relates to an optical sensor package, which includes a substrate, a sensor die coupled to the substrate, a light emitting device coupled to the substrate, and a cap. The cap is positioned around multiple side surfaces of the sensor die and covers at least a portion of the substrate. The cap includes a first side wall and a second side wall, an inner wall having a first side surface and a second side surface and a mounting surface, and a cover in contact with the first side wall, the second side wall and the inner wall. The first side surface and the second side surface are transverse to the mounting surface, and the inner wall includes an opening extending from the mounting surface into the inner wall. An adhesive material (such as glue) is disposed on the sensor die and at least partially within the opening, and secures the inner wall to the sensor die.

[0008] Specifically, the cap allows the adhesive material to flow into the opening formed in the inner wall of the cap, thereby preventing the adhesive material from overflowing upward along the side wall of the cap, which would cover the light emitting or light receiving opening of the optical sensor package. In addition, such overflow (prevented by the cap and optical sensor package provided herein) would cause one or more vents formed in the cap to become blocked.

[0009] In one or more embodiments, the cap may be attached to the substrate and / or sensor die by filling the opening in the inner wall with an adhesive material. For example, in an embodiment, the opening may include a groove formed completely through the inner wall and the cover of the cap. The adhesive material may then be applied in the groove, through the cover and onto the sensor die. In other embodiments, the opening in the cap may be formed only partially through the inner wall, in which case the adhesive material may be applied to the surface of the sensor die and the inner wall of the cap may be positioned on the adhesive material. The opening may thus accommodate a flow of adhesive material, thereby preventing overflow upward along the side surface of the inner wall. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1 is a cross-sectional view of an optical sensor package in which an adhesive overflow problem occurs.

[0011] Figure 2A is a top view of an optical sensor package including a cap according to an embodiment of the present disclosure.

[0012] Figure 2B yes Figure 2A A cross-sectional view of a light sensor package is shown in FIG.

[0013] FIG. 3A to FIG. 3C According to the embodiment of the present disclosure, the Figure 2A and Figure 2B A cross-sectional view of the method of the optical sensor package shown in FIG.

[0014] Figure 4 is a cross-sectional view of an optical sensor package according to another embodiment of the present disclosure.

[0015] Figure 5 is a cross-sectional view of an optical sensor package according to yet another embodiment of the present disclosure. DETAILED DESCRIPTION

[0016] Figure 1 An optical sensor package 10 is shown as may be known in the art. The optical sensor package 10 includes a sensor die 14 secured to a substrate 12. A light emitting device 16 is secured to the substrate 12. The optical sensor package 10 further includes a cap 20 including a sidewall 22, a cover 24, and an inner wall 26. The cap 20 includes a first opening 32 and a second opening 34 through which light emitted by the light emitting device 16 is transmitted (e.g., through the first opening 32) and light reflected by an object is received by a sensor region 18 formed in the sensor die 14 (e.g., through the second opening 34).

[0017] The first transparent window 42 and the second transparent window 44 are attached to the cap 20 (e.g., attached to the lower surface of the cover 24 as shown), and the first vent 36 is formed between the first opening 32 and the first transparent window 42, and the second vent 38 is formed between the second opening 34 and the second transparent window 44, respectively. As shown, the cap 20 is attached to the substrate 12 (e.g., the side wall 22 is attached to the substrate 12) and attached to the sensor die 14 (e.g., the inner wall 26 is attached to the sensor die 14). The cap 20 is fixed by an adhesive material (e.g., glue 46).

[0018] like Figure 1 As shown, during or after the process of attaching cap 20 to substrate 12 and sensor die 14, adhesive 46 may overflow from inner wall 26 (e.g., overflow from the lower surface or side surface of inner wall 26) beyond the side surface of inner wall 26 and enter and / or pass through either or both of vents 36, 38, thereby blocking vents 36, 38 and preventing or otherwise impeding airflow through vents 36, 38. This may occur, for example, during the installation and / or curing process of adhesive 46. In addition, as shown in FIG. Figure 1 As shown, the adhesive 46 may partially or completely cover one or both of the first opening 32 and the second opening 34 .

[0019] According to one or more embodiments provided by the present disclosure, Figure 2Ais a top view of the optical sensor package 200 including the cap 120, and Figure 2B yes Figure 2A 2B is a cross-sectional view of the optical sensor package 200. Figure 2A and Figure 2B The optical sensor package 200 is similar in structure and function to Figure 1 The optical package 10 shown is similar; however, the cap 120 of the optical sensor package 200 is different and reduces or eliminates the Figure 1 The problem of adhesive overflow associated with the cap 20 of the optical package 10 is solved.

[0020] As from Figure 2A and Figure 2B As can be seen, the cap 120 includes a side wall 122, a cover 124, and an inner wall 126. The cap 120 further includes a first opening 32 and a second opening 34 for transmitting light emitted by the light emitting device 16 (e.g., through the first opening 32) and for receiving light reflected by an object (e.g., through the second opening 34).

[0021] The first transparent window 42 and the second transparent window 44 are bonded to the cap 120 (e.g., bonded to the lower surface of the cover 124 as shown) by an adhesive material 150, which can be any material configured to securely attach the first transparent window 42 and the second transparent window 44 to the cap 120. In one or more embodiments, the adhesive material 150 can be glue. In other embodiments, the adhesive material 150 can be any adhesive material, such as paste, epoxy resin, film, tape, etc. Figure 2B As shown, the first transparent window 42 and the second transparent window 44 may be attached to a lower surface of the cap member 124 of the cap (ie, a portion of the cap 120 extending horizontally between the inner wall 126 and the side wall 122 ).

[0022] In one or more embodiments, and with Figure 1 In contrast to the cap 20 shown, the cap 20 may be formed without a vent between the transparent windows 42, 44 and the cover 124. Figure 1 The height of the cap 120 may be reduced when compared to the cap 20 shown.

[0023] The inner wall 126 of the cap 120 includes a groove 160. Figure 2BAs shown, the slot 160 can be formed completely through the inner wall 126 (e.g., from the upper surface of the cover 124 to the lower surface or mounting surface of the inner wall 126). However, in one or more embodiments, the slot 160 can be formed only partially within the inner wall 126. For example, the slot 160 can have an opening at the lower surface of the inner wall 126 and can extend upward into the inner wall 126 to a level below the upper surface of the inner wall 126.

[0024] As in Figure 2A As can be seen in the top view of , the groove 160 can have an opening extending across the upper surface of the cover 124 of the cap 120. The groove 160 can have different shapes and / or sizes. For example, in one or more embodiments, the groove 160 can be one or more through holes formed through the central portion of the inner wall 126 of the cap 120. The groove 160 can be formed by any method for forming a groove or through hole in the inner wall 126, for example, by etching, perforating, drilling, etc. through the inner wall 126 of the cap 120.

[0025] like Figure 2B As shown in , the optical sensor package 200 includes a sensor die 14 fixed to the upper surface of the substrate 12. Generally speaking, the substrate 12 includes one or more insulating layers and conductive layers. The first surface 11 (e.g., the upper surface) of the substrate 12 includes pads (not shown), and the second surface 13 (e.g., the lower surface) of the substrate 12 includes pads or soldering areas (not shown). The pads on the first surface 11 are in electrical communication with one or more pads on the second surface 13 through conductive traces and / or vias formed in the substrate 12. The second surface 13 of the substrate 12 forms the outer surface of the optical sensor package 200, and the soldering areas on the second surface 13 are used to electrically couple the optical sensor package 200 to another device or board (not shown).

[0026] The sensor die 14 is secured to the first surface 11 of the substrate 12 by an adhesive material 252. The adhesive material 252 may be any material configured to hold the sensor die 14 in place during the assembly process. For example, the adhesive material 252 may be a tape, a paste, a glue, or any other suitable material. In one or more embodiments, the adhesive material 252 is a die attach film.

[0027] The sensor die 14 is made of a semiconductor material such as silicon. The sensor die 14 includes an active surface that includes one or more electrical components such as an integrated circuit. The integrated circuit can be an analog or digital circuit that is implemented as active devices, passive devices, conductive layers, and dielectric layers that are formed within the die and electrically interconnected with functions according to the electrical design of the die. Specifically, the sensor die 14 includes electrical components that form an application specific integrated circuit (ASIC). Therefore, as is well known in the art, the sensor die 14 includes circuits for sending, receiving, and analyzing electrical signals. In the illustrated embodiment, the active surface is located at the upper portion of the sensor die 14. The upper surface of the sensor die 14 includes pads for electrically coupling the sensor die to the substrate 12.

[0028] As shown, the light emitting device 16 is secured to the first surface 11 of the substrate 12. In alternative embodiments, the light emitting device 16 may be positioned on the sensor die 14. The light emitting device 16 may be secured to the first surface 11 of the substrate 12 by an adhesive material 254. The adhesive material 254 may be any material suitable for securing the light emitting device 16 to the upper surface of the sensor die 14, such as a tape, a paste, an adhesive, a die attach film, or any other suitable material.

[0029] Light emitting device 16 is configured to emit radiation at a specific frequency or frequency range. In one embodiment, light emitting device 16 emits infrared (IR) radiation. Light emitting device 16 can be a vertical cavity surface emitting laser (VCSEL) or a light emitting diode (LED) (e.g., an infrared LED).

[0030] The light emitting device 16 is electrically coupled to the sensor die 14 (eg, directly electrically coupled to the sensor die 14 and / or via a Figure 2B The substrate 12 shown in the embodiment of FIG. 1 is directly coupled to the sensor die 14) and is configured to receive an electrical signal (e.g., a power signal from the sensor die 14) and to emit radiation at a specific frequency or frequency range in response to receiving the signal. Specifically, the sensor die 14 is electrically coupled to the substrate 12 via one or more conductive connectors, which are conductive wires 62 in the illustrated embodiment. In this regard, a first end of the conductive wire 62 is coupled to a bonding pad on the sensor die 14, and a second end of the conductive wire 62 is coupled to a pad on the first surface 11 of the substrate 12. Similarly, the light emitting device 16 is electrically coupled to the first surface 11 of the substrate 12 via one or more conductive wires 64. For example, a first end of the conductive wire 64 can be coupled to a bonding pad on the light emitting device 16, and a second end of the conductive wire 64 can be coupled to a pad on the first surface 11 of the substrate 12. In this way, the light emitting device 16 can be in electrical communication with the sensor die 14 through the substrate 12.

[0031] In another embodiment, the conductive connectors are conductive bumps such that the sensor die 14 and / or the light emitting device 16 are coupled to the substrate 12 via a flip chip configuration as is well known in the art.

[0032] The sensor die 14 includes a sensor region 18 formed in or otherwise coupled to an upper surface of the sensor die 14. The light emitting device 16 emits radiation in response to an electrical signal received from the sensor die 14, and the sensor region 18 receives reflected radiation and provides an electrical signal for processing to the sensor die 14. In one or more embodiments, the sensor region 18 may be or include an array of photosensitive elements, such as a photodiode array, a single photon avalanche diode (SPAD) array, and similar arrays configured to detect reflected radiation.

[0033] The sidewall 122 of the cap 120 is fixed to the first surface 11 of the substrate 12, and the inner wall 126 of the cap 120 is fixed to the upper surface of the sensor die 14 between the light emitting device 16 and the sensor area 18. The cap 120 is fixed by an adhesive material 146, which can be any adhesive material and can be different from or the same as those adhesive materials described above. In one embodiment, the adhesive material 146 is made of an adhesive material configured to form a light baffle, such as black glue. In one or more embodiments, the adhesive material 146 is a flowable adhesive material.

[0034] The inner wall 126 of the cap 120 forms a light barrier between the light emitting device 16 and the sensor region 18. That is, the inner wall 126 of the cap 120 prevents light emitted from the light emitting device 16 from being received by the sensor region 18 through the inner wall 126. In contrast, the sensor region 18 is optically isolated by the cap 120 except for light received through the second opening 34.

[0035] The cap 120 may be formed of any rigid or semi-rigid material, such as a plastic material. In one embodiment, the cap 120 is formed of liquid crystal plastic.

[0036] In operation, the sensor die 14 is configured to cause the light emitting device 16 to emit light through the first opening 32. The emitted light is reflected by nearby objects and travels through the second opening 34, and the sensor region 18 receives the reflected light. The sensor die 14 receives signals from the sensor region 18 and is configured to process the signals generated by the sensor region 18 when receiving the reflected light.

[0037] FIG. 3A to FIG. 3C According to various embodiments, manufacturing Figure 2A and Figure 2B The various steps of the method of the optical sensor package 200 are as follows. Figure 3A As shown, a cap 120 is provided, which can be as shown in FIG. Figure 2B The cap 120 is shown including a groove 160. Similarly, a substrate 12 is provided wherein the sensor die 14 and the light emitting device 16 are attached to the first surface 11 of the substrate 12 by adhesive materials 252, 254, respectively. As described above, the sensor die 14 and the light emitting device 16 are electrically coupled to the substrate 12 by conductive lines 62, 64, respectively.

[0038] The adhesive material 146 is applied to the first surface 11 of the substrate 12 at a location outside the sensor die 14 and the light emitting device 16. Alternatively, the adhesive material 146 may be applied to the lower surface of the sidewall 122 of the cap 120. The cap 120 is positioned so that the sidewall 122 is directly above the adhesive material 146, and the inner wall 126 including the groove 160 is positioned above the upper surface of the sensor die 14.

[0039] like Figure 3B As shown, cap 120 is lowered onto substrate 12 such that the lower surface of sidewall 122 contacts adhesive material 146 on substrate 12. Downward pressure may be applied to cap 120 to position cap 120 on substrate 12 as desired.

[0040] like Figure 3C As shown, after the cap 120 has been attached to the substrate 12 (i.e., the sidewall 122 of the cap 120 is attached to the substrate 12 via the adhesive material 146), the groove 160 can be completely or partially filled with an adhesive material 146 (e.g., glue). The groove 160 can be filled by applying the adhesive material 146 through the groove 160 onto the upper surface of the sensor die 14 until an appropriate amount of the adhesive material 146 fills the groove 160. The adhesive material 146 can then be left to cure, thereby securely attaching the cap 120 to the substrate 12 and the sensor die 14.

[0041] As mentioned above about Figure 2A and Figure 2B As noted, the groove 160 may be formed only partially within the inner wall 126. For example, the groove 160 may have an opening at the lower surface of the inner wall 126 and may extend upward into the inner wall 126 to a level below the upper surface of the inner wall 126. In this case, a method for forming an optical sensor package having such a cap is as follows. FIG. 3A to FIG. 3C; however, instead of filling the groove 160 with adhesive material 146 through the opening at the top of the cap, adhesive material 146 can be applied to the upper surface of sensor die 14 as well as substrate 12 (e.g., as described above for attaching sidewall 122 to substrate 12). The cap can then be pressed onto adhesive material 146 in a single step, and adhesive material 146 applied to the upper surface of sensor die 14 can be pushed into groove 160 formed in inner wall 126. Thus, adhesive material 146 can move upward through groove 160, rather than overflowing over the outer surface of inner wall 126.

[0042] Figure 4 is a cross-sectional view of an optical sensor package 300 including a cap 220 according to one or more embodiments. In addition to the differences discussed below, Figure 4 The optical sensor package 300 is similar in structure and function to Figure 2A and Figure 2B For the sake of brevity, features common to the optical sensor packages 200 and 300 will not be described again herein.

[0043] Figure 2A and Figure 2B The optical sensor package 200 is shown with Figure 4 One difference between the optical sensor package 300 shown is that the cap 220 of the optical sensor package 300 does not include a groove through the inner wall 226. Another difference is that the inner wall 226 of the cap 220 includes a stepped recess 262. Figure 1 In contrast to the inner wall 26 of the cap 20 shown, which has a uniform contour and thereby causes the adhesive 46 to overflow upward and beyond the outer surface of the inner wall 26 when the cap 20 is attached to the substrate 12, the stepped recess 262 of the inner wall 226 provides volume on each side of the inner wall 226 for accommodating the flow of adhesive material 146 when the cap 20 is installed and cured (e.g., when the cap 220 is pressed onto the adhesive material 146 applied to the substrate 12 and the sensor die 14, and when the adhesive material 146 cures to securely attach the cap 220 to the substrate 12 and the sensor die 14).

[0044] like Figure 4 As shown, the optical sensor package 300 may include a first vent 36 and a second vent 38, which are respectively located between the first and second openings 32, 34 and the first and second transparent windows 42, 44. In addition, as shown, the cap 220 may include a stepped extension located at the junction of the side wall 222 and the cover 224.

[0045] Figure 5is a cross-sectional view of an optical sensor package 400 including a cap 320 according to one or more embodiments. In addition to the differences discussed below, Figure 5 The optical sensor package 400 is similar in structure and function to Figure 4 For the sake of brevity, features common to the optical sensor packages 300 and 400 will not be described again herein.

[0046] Figure 4 The optical sensor package 300 is shown with Figure 5 The main difference between the optical sensor packages 400 shown is that the cap 320 of the optical sensor package 400 does not include a stepped recess, but instead includes recesses 361, 362, 363 formed in respective portions of the inner wall 326 of the cap 320. These recesses 361, 362, 363 may be formed at the same level (i.e., at the same distance from the upper or lower surface of the inner wall 326), or they may be staggered relative to each other. For example, the first recess 361 may be formed to extend from the first side surface 370 into the inner wall 326, and the second recess 362 may be formed to extend from the second side surface 372 into the inner wall 326. As shown in FIG. Figure 5 As shown, the first recess 361 and the second recess 362 may be formed at the same level. The third recess 363 may be formed along the inner wall 326 at a different level than the first recess 361 and the second recess 362. Further, the inner wall 326 may include one or more extensions 380. Figure 5 As shown, the extension 380 can be a portion of the inner wall 326 that extends outward (e.g., horizontally relative to the substantially vertical orientation of the inner wall 326 as shown) beyond the second side surface 372. The extension 380 includes a first surface, a second surface, and a third surface (e.g., an upper surface, a lower surface, and a side surface as shown).

[0047] The recesses 361, 362, 363 formed in the inner wall 326 provide volumes at different heights along each side of the inner wall 326 for accommodating the flow of the adhesive material 146 when the cap 320 is installed and cured. In addition, the extensions 380 formed in the inner wall 326 can provide increased volume (i.e., in the second recess 362 and the third recess 363) for accommodating the flow of the adhesive material 146, thereby storing the adhesive material 146 and preventing the adhesive material 146 from overflowing upward along the side surface of the inner wall 326 and blocking the vents or shielding the openings 32, 34. Any number of recesses can be formed in the inner wall 326 and can be located anywhere along the inner wall 326. Further, one or more extensions 380 can be formed anywhere along the inner wall 326, extending outward to form a recess with an increased volume, which is used to store the flow of the adhesive material and prevent or otherwise accommodate the overflow of the adhesive material.

[0048] like Figure 5 As shown, in one or more embodiments, the cap 320 may include a stepped extension at the junction of the side wall 322 and the cover 324 .

[0049] An optical sensor package having any of the caps described herein (e.g., caps 120, 220, 320 of optical sensor packages 200, 300, 400, respectively) can be included in various electronic devices and can be coupled to, for example, a microprocessor, a power source, a memory, or other such electronic components. An electronic device including an optical sensor package described herein can also include, for example, a cellular phone, a smart phone, a tablet computer, a camera, and / or a wearable computing device that can be located in clothing, shoes, watches, glasses, or any other wearable structure. In some embodiments, such electronic devices or optical sensor packages described herein can be located in vehicles such as ships and cars, robots, or any other movable structure or machine.

[0050] The above-described embodiments may be combined to provide further embodiments. In view of the above detailed description, these and other changes may be made to the embodiments. In summary, in the following claims, the terms used should not be interpreted as limiting the claims to the specific embodiments disclosed in the specification and claims, but should be interpreted to include all possible embodiments, together with the entire range of equivalents to which these claims are entitled. Accordingly, the claims are not limited by the present disclosure.

Claims

1. An optical sensor package, comprising: substrate; a sensor die coupled to the substrate; a light emitting device coupled to the substrate; as well as a cap positioned around a side surface of the sensor die and covering at least a portion of the substrate, the cap comprising: a first side wall and a second side wall, an inner wall having first and second side surfaces and a mounting surface, the first and second side surfaces being perpendicular to the mounting surface, the inner wall comprising an opening extending from the mounting surface into the inner wall, and a cover member in contact with the first and second side walls and the inner wall; as well as a first adhesive material located over the sensor die and at least partially within the opening, the first adhesive material securing the inner wall to the sensor die, The inner wall includes an extension portion extending outward beyond the second side surface, and the opening includes a first recessed portion extending from the mounting surface into the inner wall and adjacent to a first surface of the extension portion.

2. The optical sensor package of claim 1, wherein the opening comprises a slot extending from the mounting surface of the inner wall through the inner wall and through the cover. 3 . The optical sensor package of claim 1 , wherein the opening comprises a first recess extending from the mounting surface and from the first side surface of the inner wall into the inner wall.

4. The optical sensor package of claim 3, further comprising a second recess extending from the mounting surface and from the second side surface of the inner wall into the inner wall, the first adhesive material being at least partially located within the second recess. 5 . The optical sensor package of claim 1 , further comprising a second recessed portion extending from the second side surface of the inner wall into the inner wall and adjacent to the second surface of the extending portion. 6 . The optical sensor package of claim 5 , further comprising a third recess extending from the first side surface of the inner wall into the inner wall.

7. The optical sensor package of claim 1, wherein the light emitting device comprises at least one of a vertical cavity surface emitting laser (VCSEL) and a light emitting diode (LED).

8. The optical sensor package of claim 1, further comprising: a second adhesive material positioned between the first sidewall of the cover and the base; as well as A third adhesive material is positioned between the second side wall of the cover and the base, the second and third adhesive materials securing the first and second side walls, respectively, to the base. 9 . The optical sensor package of claim 8 , wherein the first adhesive, the second adhesive, and the third adhesive comprise glue.

10. A cap for an optical sensor package, the cap comprising: a first side wall and a second side wall; Inner wall; as well as a cover member in contact with the first and second side walls and the inner wall, the inner wall comprising an opening extending from a first surface of the inner wall into the inner wall, the opening being configured to receive an adhesive material, The inner wall includes a first side surface and a second side surface transverse to the first surface, and an extension portion extending outward beyond the second side surface, wherein the opening includes a first recessed portion extending from the first surface of the inner wall into the inner wall and adjacent to the first surface of the extension portion.

11. The cap of claim 10, wherein the opening comprises a slot extending from the first side surface of the inner wall into the inner wall.

12. The cap of claim 11 wherein the slot extends through the inner wall and through the cover member.

13. The cap of claim 10, wherein the opening comprises a first recess extending from the first surface of the inner wall and from a first side surface of the inner wall into the inner wall, the first side surface being transverse to the first surface.

14. The cap of claim 13, wherein the inner wall further comprises a second recess extending into the inner wall from the first surface of the inner wall and from a second side surface of the inner wall, the second side surface being opposite the first side surface and transverse to the first surface.

15. The cap of claim 10, wherein the inner wall further comprises a second recess extending from the first side surface of the inner wall into the inner wall.

16. A method comprising: forming a cap for an optical sensor package, the cap comprising a first side wall and a second side wall, an inner wall, and a cover member in contact with the first side wall, the second side wall and the inner wall, the inner wall having a first side surface, a second side surface and a mounting surface, the first side surface and the second side surface being transverse to the mounting surface, the inner wall comprising an opening extending from the mounting surface into the inner wall; positioning the first sidewall and the second sidewall of the cap on a substrate; positioning the mounting surface of the inner wall of the cap over a sensor die coupled to the substrate; as well as providing a first adhesive material on the sensor die and at least partially within the opening of the inner wall of the cap, the first adhesive material securing the inner wall to the sensor die, The inner wall includes an extension portion extending outward beyond the second side surface, and the opening includes a first recessed portion extending from the mounting surface into the inner wall and adjacent to a first surface of the extension portion.

17. The method of claim 16, wherein the opening comprises a slot extending from the mounting surface of the inner wall through the inner wall and through the cover, and providing the adhesive material comprises providing the first adhesive material through the slot and onto the sensor die.

18. The method of claim 16, wherein the opening comprises a first recess extending from the mounting surface and from the first side surface of the inner wall into the inner wall.

19. The method of claim 18, wherein the inner wall includes a second recess extending into the inner wall from the mounting surface and from the second side surface of the inner wall, and providing the first adhesive material includes providing the first adhesive material at least partially within the second recess.

20. The method of claim 16, further comprising: providing a second adhesive material between the first sidewall of the cap and the base; as well as A third adhesive material is provided between the second side wall of the cap and the base, and the second adhesive material and the third adhesive material fix the first side wall and the second side wall to the base, respectively.

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