Optical package structure
By using spacer and reflector design in the optical packaging structure, combined with flip chip bonding technology, the problems of high emissivity and non-compact structure of the packaging layer are solved, and the light sensing effect with smaller size and higher accuracy is achieved.
Patent Information
- Application Number
- CN202422192864.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-09-06
- Publication Date
- 2025-08-26
- Estimated Expiration
- 2034-09-06
AI Technical Summary
The encapsulation layer of the existing optical packaging structure has a high emissivity, which affects the accuracy of the temperature sensing of the photodiode. The packaging structure is not compact enough, and the need to use lead connections leads to a larger size.
The spacer and reflector design are adopted. The light sensor is located in the space defined by the spacer and the active device. The spacer material is silicon or metal with low emissivity, and the reflector is metal. The light sensor directly connects the substrate through flip chip bonding, cancels the lead connection, and optimizes the optical path with the lens and metal layer.
Improves the accuracy of light sensing, reduces the size of the package structure, enhances the signal-to-noise ratio, and achieves a more compact package structure.
Smart Images
Figure CN223274452U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to an optical packaging structure. Background Art
[0002] Figure 1 The figure shows an optical package (PKG) of the prior art, including a substrate / lead frame 3, an electronic component 4, a photodiode 2, an encapsulation layer 1, and a reflective layer 5. The electronic component 4 is electrically connected to the substrate / lead frame 3 via leads 6. The package requires the encapsulation layer 1 to maintain a small size. The small-sized package is suitable for wearable devices. However, due to the high emissivity of the encapsulation layer 1, the encapsulation layer 1 easily absorbs thermal radiation, which affects the interpretation of the temperature sensing of the photodiode (PD) 2 and affects the accuracy of the sensing results.
[0003] Figure 2 The optical packages of other embodiments of the prior art are shown, in which the electronic component 4 with an integrated thermopile element 7 for sensing is used instead of the photodiode 2 , and the lens 9 is adhered to the electronic component 4 by an adhesive layer 8 . The response speed of the thermopile element 7 is slower than that of the photodiode 2 .
[0004] in addition, Figure 1 and Figure 2 The embodiments shown all require the use of wires 6 to bond the electronic component 4 and the substrate / lead frame 3 , which makes the size of the optical package not compact enough. Utility Model Content
[0005] In view of the problems existing in the related art, the purpose of the present invention is to provide an optical packaging structure to improve the sensing accuracy of the optical packaging structure and reduce the size of the optical packaging structure.
[0006] To achieve the above-mentioned objectives, the present invention provides an optical packaging structure, comprising: an active device having an active surface and a passive surface arranged opposite to each other; a light sensor engaged with the passive surface of the active device; a spacer located on the passive surface of the active device, and the light sensor located in the space defined by the spacer and the active device.
[0007] In some embodiments, the optical packaging structure further includes: a reflector located on the spacer, and the optical sensor is located in a space defined by the reflector, the spacer, and the active device.
[0008] In some embodiments, the spacer is integrally formed with the reflector.
[0009] In some embodiments, the spacer and the reflector are made of metal.
[0010] In some embodiments, the optical packaging structure further includes: a metal layer located on the inner surface of the reflector, the metal layer surrounding an opening exposing the top surface of the light sensor, and projected in a vertical direction, the opening is aligned with an edge of the light sensor.
[0011] In some embodiments, the spacer and the reflector are made of metal. The reflector surrounds the opening exposing the top surface of the light sensor. Projected in a vertical direction, the opening is aligned with an edge of the light sensor.
[0012] In some embodiments, the optical packaging structure further includes: a lens located on the spacer, and the optical sensor is located in a space defined by the lens, the spacer, and the active device.
[0013] In some embodiments, the spacer is integrally formed with the lens.
[0014] In some embodiments, the material of the spacer and the lens is silicon.
[0015] In some embodiments, the optical packaging structure further includes: a metal layer located on outer surfaces of the spacer and the lens, the metal layer including an opening projected in a vertical direction, the opening being aligned with an edge of the optical sensor.
[0016] In some embodiments, the optical packaging structure further includes: a light blocking member located outside the spacer and the lens, the light blocking member including an opening projected in a vertical direction, and the opening is aligned with an edge of the light sensor.
[0017] In some embodiments, the material of the spacer is metal and the material of the lens is silicon.
[0018] In some embodiments, the optical packaging structure further includes: a metal layer located between the spacer and the lens, the metal layer including an opening, projected in a vertical direction, and the opening is aligned with an edge of the optical sensor.
[0019] In some embodiments, the active device includes a through-silicon via (TSV) electrically connecting the active side and the passive side.
[0020] In some embodiments, the active device is an application specific integrated circuit chip.
[0021] In some embodiments, the light sensor is wire-bonded to the passive side of the active device.
[0022] An embodiment of the present application also provides an optical packaging structure, including: an active device having an active surface and a passive surface arranged opposite to each other; a light sensor directly bonded to the passive surface of the active device; a spacer located on the passive surface of the active device, and the light sensor located in the space defined by the spacer and the active device.
[0023] In some embodiments, the optical packaging structure further includes a lens located on the spacer, and the light sensor receives light passing through the lens.
[0024] In some embodiments, the top surface of the lens is upwardly convex.
[0025] In some embodiments, the optical packaging structure further includes: a metal layer located on the lens, the metal layer including an opening, projected in a vertical direction, the opening aligned with the edge of the light sensor, and the bottom surface of the lens protrudes downward.
[0026] The beneficial technical effects of the present utility model are:
[0027] The optical sensor of the embodiment of the present application is not covered by the high-emissivity packaging layer of the prior art, and the sensing of the optical sensor is more accurate. The spacer replaces the packaging layer of the prior art. The optical sensor is arranged on the passive surface of the active device, and the active surface of the active device faces the outside of the optical packaging structure. The optical packaging structure is a wafer-level stacking structure that can be directly bonded to external devices. The active device can be directly bonded to an additional substrate / lead frame through flip-chip bonding (FCB), and the external electrical connection of the optical packaging structure can be achieved without the use of leads. Compared with the prior art, the space used for connecting leads of the active device is saved, and the overall size of the optical packaging structure is reduced. BRIEF DESCRIPTION OF THE DRAWINGS
[0028] Aspects of the present disclosure are best understood from the following detailed description when read in conjunction with the accompanying drawings. It should be noted that, in accordance with standard practice in the industry, the various components are not drawn to scale. In fact, the dimensions of the various components may be arbitrarily increased or decreased for clarity of discussion.
[0029] Figure 1 A prior art optical package is shown.
[0030] Figure 2 Optical packages according to other prior art embodiments are shown.
[0031] Figure 3 An optical packaging structure according to a first embodiment of the present application is shown.
[0032] Figure 4 An optical packaging structure according to a second embodiment of the present application is shown.
[0033] Figure 5 An optical packaging structure according to a third embodiment of the present application is shown.
[0034] Figure 6 An optical packaging structure according to a fourth embodiment of the present application is shown.
[0035] Figure 7 An optical packaging structure according to a fifth embodiment of the present application is shown.
[0036] Figure 8An optical packaging structure according to a sixth embodiment of the present application is shown.
[0037] Figure 9 An optical packaging structure according to a seventh embodiment of the present application is shown.
[0038] Figure 10 An embodiment is shown in which the light sensor is integrated on the passive side of the active device.
[0039] Figure 11 An optical packaging structure according to an eighth embodiment of the present application is shown. DETAILED DESCRIPTION
[0040] In order to better understand the spirit of the embodiments of the present application, some preferred embodiments of the present application are further described below.
[0041] The embodiments of the present application will be described in detail below. Throughout this specification, identical or similar components and components having identical or similar functions are represented by similar reference numerals. The embodiments described herein with respect to the accompanying drawings are illustrative and diagrammatic and are intended to provide a basic understanding of the present application. The embodiments of the present application should not be construed as limiting the present application.
[0042] As used herein, the terms "substantially," "substantially," and "approximately" are used to describe and illustrate small variations. When used in conjunction with an event or circumstance, the terms may refer to instances where the event or circumstance occurred precisely as well as instances where the event or circumstance occurred very approximately.
[0043] In this specification, unless otherwise specified or limited, relative terms such as "central", "longitudinal", "lateral", "front", "rear", "right", "left", "inner", "outer", "lower", "higher", "horizontal", "vertical", "above", "below", "above", "below", "top", "bottom" and their derivatives (such as "horizontally", "downwardly", "upwardly", etc.) should be interpreted as referring to the directions described in the discussion or depicted in the drawings. These relative terms are only used for convenience of description and do not require that the present application be constructed or operated in a specific orientation.
[0044] For ease of description, “first,” “second,” “third,” etc. may be used herein to distinguish different components in a figure or a series of figures. “First,” “second,” “third,” etc. are not intended to describe the corresponding components.
[0045] Figure 3The optical packaging structure 100 according to the first embodiment of the present application is shown, including an active device 10, a light sensor 20, and a spacer 30. The active device 10 has an active surface 12 and a passive surface 14 arranged opposite to each other; the light sensor 20 is bonded to the passive surface 14 of the active device 10; the spacer 30 is located on the passive surface 14 of the active device 10, and the light sensor 20 is located in a space 90 defined by the spacer 30 and the active device 10. The light sensor 20 of the embodiment of the present application is not covered by the high-emissivity packaging layer of the prior art, and the sensing of the light sensor 20 is more accurate. The spacer 30 replaces the packaging layer of the prior art, and the light sensor 20 is arranged on the passive surface of the active device 10. The active surface 12 of the active device 10 faces the outside of the optical packaging structure 100. The optical packaging structure 100 is a wafer-level structure that can be directly bonded to external devices. In the embodiment of the prior art, the active surface of the electronic components faces upward, so it is necessary to use leads 6 to bond to the substrate / lead frame 3 below. The active device 10 of the embodiment of the present application can be directly bonded to the additional substrate / lead frame through flip chip bonding (FCB), and the external electrical connection of the optical packaging structure 100 can be achieved without the use of leads. Compared with the prior art, the space used for connecting leads of the active device 10 is saved, and the overall size of the optical packaging structure 100 is reduced.
[0046] The spacer 30 is made of low-emissivity silicon or metal that blocks thermal radiation, preventing absorption of thermal radiation that could affect the sensing results of the optical sensor 20. The optical package 100 further includes a reflector 40 positioned on the spacer 30. The optical sensor 20 is positioned within a space 90 defined by the reflector 40, the spacer 30, and the active device 10. In some embodiments, the spacer 30 is made of silicon and the reflector 40 is made of metal to meet high emissivity requirements. In some embodiments, the spacer 30 and the reflector 40 are integrally formed and comprise the same material, such as metal. The reflective member 40 surrounds an opening 60 exposing the top surface of the optical sensor 20. Projected in the vertical direction, the opening 60 is aligned with the edge of the optical sensor 20. The optical sensor 20 receives light only from the opening 60, making it suitable for optical sensors 20 with a small field of view (FOV) and a small package size. By receiving light only from the opening 60, the optical sensor 20 can prevent the optical sensor 20 from receiving other noise, thereby improving the signal-to-noise ratio (SNR) of the optical package structure 100.
[0047] In some embodiments, active device 10 is an application-specific integrated circuit (ASIC) chip. Active device 10 includes through-silicon vias (TSVs) electrically connecting active surface 12 and passive surface 14. Optical sensor 20 can be directly bonded to passive surface 14 of active device 10 via flip-chip bonding (FCB) or wire-bonded to passive surface 14 of active device 10. Optical sensor 20 is an infrared sensor for temperature sensing, such as an infrared photodiode (PD).
[0048] Figure 4 An optical package structure 100 according to a second embodiment of the present application is shown, wherein the optical package structure 100 further includes a lens 70 located on a spacer 30. The optical sensor 20 is located in a space 90 defined by the lens 70, the spacer 30, and the active device 10. The optical sensor 20 receives light passing through the lens 70. In some embodiments, the material of the lens 70 is high-emissivity silicon, and the material of the spacer 30 is metal or silicon.
[0049] Figure 5 An optical packaging structure 100 according to a third embodiment of the present application is shown, wherein the spacer 30 and the reflector 40 are integrally formed liquid crystal polymer (LCP), and the optical packaging structure 100 also includes a metal layer 50 located on the inner surfaces of the reflector 40 and the spacer 30. The metal layer 50 can be a coating or plating with high flatness. The metal layer 50 surrounds an opening 60 that exposes the top surface of the light sensor 20. Projected in the vertical direction, the opening 60 is aligned with the edge of the light sensor 20.
[0050] Figure 6 An optical packaging structure 100 according to a fourth embodiment of the present application is shown, wherein the spacer 30 and the lens 70 are integrally formed, and the spacer 30 and the lens 70 comprise the same material, such as silicon.
[0051] Figure 7 An optical packaging structure 100 according to the fifth embodiment of the present application is shown, wherein, based on the second embodiment, a metal layer 50 is arranged between the spacer 30 and the lens 70, and the metal layer 50 includes an opening 60, which is projected in the vertical direction and is aligned with the edge of the light sensor 20.
[0052] Figure 8 An optical packaging structure 100 according to the sixth embodiment of the present application is shown, wherein, based on the fourth embodiment, the optical packaging structure 100 also includes a light-blocking member 80 located outside the spacer 30 and the lens 70, the light-blocking member 80 includes a support member 82 and a metal layer 50 located on the inner side of the support member 82, the light-blocking member 80 includes an opening 60, and when projected in the vertical direction, the opening 60 is aligned with the edge of the light sensor 20.
[0053] Figure 9 An optical packaging structure 100 according to a seventh embodiment of the present application is shown. In the second, fourth, to sixth embodiments, the bottom surface of the lens 70 is planar, and the top surface of the lens 70 protrudes away from the optical sensor 20 to receive more light. In the seventh embodiment, the top surface of the lens 70 is planar, and the bottom surface of the lens 70 protrudes toward the optical sensor 20 to focus the received light onto the optical sensor 20. The optical packaging structure 100 further includes a metal layer 50 located on the outer surfaces of the spacer 30 and the lens 70. The metal layer 50 includes an opening 60. Projected in the vertical direction, the opening 60 is aligned with the edge of the optical sensor 20.
[0054] The optical sensor 20 of the first to seventh embodiments is directly bonded to the passive surface 14 of the active device 10 by flip chip bonding (FCB). Figure 10 An embodiment is shown in which the light sensor 20 is integrated on the passive surface 12 of the active device 10 .
[0055] Figure 11 An optical packaging structure 100 according to an eighth embodiment of the present application is shown, wherein a plurality of optical sensors 20 forming an array are integrated on the passive surface 12 of the active device 10 , and the optical sensors 20 forming the array can be used to sense images.
[0056] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Those skilled in the art will readily appreciate that the present invention is susceptible to various modifications and variations. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention shall be included within the scope of protection of the present invention.
Claims
1. An optical packaging structure, characterized in that: include: An active device having an active surface and a passive surface arranged opposite to each other; a light sensor bonded to the passive surface of the active device; A spacer is located on the passive surface of the active device, and the light sensor is located in a space defined by the spacer and the active device.
2. The optical packaging structure according to claim 1, wherein: Also includes: The reflective element is located on the spacer, and the light sensor is located in a space defined by the reflective element, the spacer, and the active device.
3. The optical packaging structure according to claim 2, wherein: The spacer and the reflector are formed integrally.
4. The optical packaging structure according to claim 3, wherein: The spacer and the reflector are made of metal.
5. The optical packaging structure according to claim 3, wherein: Also includes: The metal layer is located on the inner surface of the reflective element. The metal layer surrounds an opening that exposes the top surface of the light sensor. When projected in a vertical direction, the opening is aligned with an edge of the light sensor.
6. The optical packaging structure according to claim 3, wherein: The spacer and the reflector are made of metal. The reflector surrounds an opening that exposes the top surface of the light sensor. Projected in a vertical direction, the opening is aligned with an edge of the light sensor.
7. The optical packaging structure according to claim 1, wherein: Also includes: The lens is located on the spacer, and the light sensor is located in a space defined by the lens, the spacer, and the active device.
8. The optical packaging structure according to claim 7, wherein: Also includes: A metal layer is located on the outer surface of the spacer and the lens, wherein the metal layer comprises an opening projected in a vertical direction, and the opening is aligned with the edge of the light sensor.
9. The optical packaging structure according to claim 7, wherein: Also includes: A light blocking member is located outside the spacer and the lens. The light blocking member includes an opening projected in a vertical direction. The opening is aligned with an edge of the light sensor.
10. The optical packaging structure according to claim 1, wherein: The active device includes a through-silicon via electrically connecting the active surface and the passive surface.