Optical system-in-package using semiconductor packaging, and manufacturing method therefor

Abstract

The present invention relates to an optical system-in-package (O-SIP) and a manufacturing method therefor, in which a pad surface for electrical connection of an optical element and an optical surface for the input or output of optical signals of the optical element are disposed on opposite surfaces. In the optical system-in-package (O-SIP) according to the present invention, the pad surface for electrical connection of the optical element and the optical surface for the input or output of the optical signals may be located on opposite surfaces. The optical system-in-package (O-SIP) may have a 2.5D packaging structure in which the optical element and an electronic element are packaged in the same mold body, or may have a 3D packaging structure in which a package including the optical element is stacked and assembled on the electronic element.

Description

Optical system-in-package using semiconductor packaging and its manufacturing method

[0001] The present invention relates to an optical system-in-package including an optical element, and more particularly, to an optical system-in-package in which a pad surface on which electrical connection to the optical element is made and an optical surface on which an optical signal to the optical element is input or output are arranged on opposite surfaces, and a method for manufacturing the same.

[0002] Semiconductor chips not only function as integrated circuits (ICs), but can also be used to create photodetectors that react to light or light-emitting elements that emit light. These optical elements are used in a variety of fields. For example, they can be used in optical transceivers that facilitate optical connections between servers, or in modules that transmit image data between TVs and set-top boxes, or between VR glasses and graphics processing units. Another application is proximity sensors, time-of-flight (TOF) sensors, and LIDARs that incorporate light-emitting elements, which can be used to measure distances.

[0003] Optical devices must be used in conjunction with electronic components (e.g., drivers) that drive or interface them, converting optical signals into electronic signals or vice versa. For example, in the field of optical data transmission, optical and electronic components are used in modules that convert optical signals into digital signals. Another example is in the field of optical sensors, where they can be used in image sensing components that convert the characteristics of received light into image data or depth data.

[0004] All of the above applications utilize conventional technologies, primarily using printed circuit boards (PCBs) with pre-designed wiring patterns to mount chips and connect them using wire bonding. This is typically a Chip-on-Board (CoB) package. Semiconductor packaging can also be used to package optoelectronic and electronic devices at the wafer level, enabling the creation of ultra-thin packages while utilizing high-precision wiring to enhance performance.

[0005] The present invention can be applied to a case where a terminal pad (pad surface) responsible for electrical connection of an optical device used for packaging an optical device and an electronic device at a wafer level and an optical surface through which an optical signal is input / output are located on opposite surfaces.

[0006] The above optical element includes various types, such as a VCSEL (Vertical Cavity Surface Emitting Laser) as a light-emitting element, a PD (Photodiode) as a light-receiving element, and a CIS (CMOS Image Sensor), and it is required that the light-emitting surface or light-receiving surface through which an optical signal is input / output and the terminal pad (pad surface) that performs electrical connection with the outside of the element are on different surfaces.

[0007] This is because it is easy to form a terminal pad, which is an electrode, on the surface where the junction, which performs the optical function of inputting / outputting optical signals, is processed. However, with the development of TSV (Through Silicon Via) technology and the securing of light transmittance through the substrate in the case of ultraviolet (IR) signals, a device form in which the light entrance / exit is formed on the back side, which is the opposite surface of the pad surface where the terminal pad is located, is required.

[0008] In particular, when using the opposite side of the pad surface, the entire anti-reflection (AR) coating can be applied using the flat surface, which is simpler than using the surface with the terminal pad as the optical surface. In addition, it can have the advantage of being able to manufacture structures that perform various optical functions, such as a microlens array or diffuser, through a process on the optical surface.

[0009] However, when using this structure, there is a problem in that the light-emitting portion is covered by an opaque mold when integrating optical elements within the panel mold during the FOWLP (Fan Out Wafer Level Package) process. Furthermore, even if a transparent mold is used, if there are optical structures on multiple surfaces, they will be covered, resulting in the loss of the structure's optical function.

[0010] The present invention has been devised in consideration of such problems, and provides an optical system-in-package (O-SIP) and a manufacturing method thereof, in which a pad surface on which electrical connection to an optical element is made and an optical surface on which an optical signal to the optical element is input and output are arranged on opposite surfaces.

[0011] In addition, the present invention provides a method for manufacturing an optical system-in-package (O-SIP) by integrating a specific structure having an optical function or a mechanical function on an optical surface through which an optical signal passes into a semiconductor package.

[0012] Furthermore, the present invention provides an optical system-in-package (O-SIP) and a manufacturing method thereof that can package the optical device while maintaining the characteristics of the optical surface of the optical device when packaging the optical device using a FOWLP or FIWLP (Fan In Wafer Level Package) process.

[0013] In order to achieve the above object, an optical system-in-package (O-SIP) according to one embodiment of the present invention is characterized by including: an optical device having an optical surface on a first surface of an optical device body through which an optical signal is input or output, and a pad surface on a second surface opposite to the optical surface, wherein a terminal pad is exposed and an electrical connection to the outside is made; a mold body surrounding an outer side of the optical device body; and a redistribution layer formed on the pad surface of the optical device body to electrically connect the terminal pad of the optical device and an external connection terminal.

[0014] An optical system-in-package (O-SIP) according to one embodiment of the present invention further includes a plurality of micro lens arrays formed on the optical surface for focusing or collimating light when an optical signal is input or output, and the optical element may be a CMOS Image Sensor (CIS).

[0015] In addition, an optical system-in-package (O-SIP) according to one embodiment of the present invention further includes a single lens or a plurality of lens arrays formed on the optical surface for focusing or collimating light when an optical signal is input or output, and the optical element may be a Vertical Cavity Surface Emitting Laser (VCSEL) or a Photodiode (PD).

[0016] The upper part of the mold body is set as a flat surface to match the optical surface, and the flat surface may further include an optical coating layer that performs an optical function.

[0017] When the optical element is any one of a VCSEL (Vertical Cavity Surface Emitting Laser), a PD (Photodiode), and a CIS (CMOS Image Sensor), the optical coating layer may be an anti-reflection (AR) coating.

[0018] If the optical element is a PD (Photodiode) or CIS (CMOS Image Sensor), the optical coating layer may be a BPF (Band Pass Filter) coating. In addition, if the optical element is a VCSEL (Vertical Cavity Surface Emitting Laser), the optical coating layer may be a diffuser.

[0019] An optical system-in-package (O-SIP) according to one embodiment of the present invention may further include an electronic component embedded within the mold body and driving or interfacing the optical component.

[0020] In this case, the mold body can be opened so that the optical surface of the optical element is not covered by the molding material.

[0021] In addition, the upper part of the mold body is set to a flat surface to match the optical surface, and the flat surface may further include an optical coating layer that performs an optical function.

[0022] Moreover, when the optical element is a photodetector, the electronic element can convert an optical signal incident through the optical element into an electronic signal, and then amplify the obtained electronic signal and convert it into a digital signal.

[0023] An optical system-in-package (O-SIP) according to one embodiment of the present invention may further include an electronic component that drives or interfaces the optical component and is coupled to a lower portion of the optical system-in-package (O-SIP) such that the external connection terminal is connected to a terminal pad exposed on the upper surface.

[0024] An optical system-in-package (O-SIP) according to one embodiment of the present invention may further include a heat-dissipating metal frame having a through hole in the central portion and a step portion formed in the lower inner portion so that the side of the electronic element is in close contact with the step portion to dissipate heat generated from the electronic element; and a heat-dissipating filler filled between the mold body and the inner portion of the heat-dissipating metal frame to transfer heat generated from the optical element to the heat-dissipating metal frame in the lateral direction.

[0025] A method for manufacturing an optical system-in-package (O-SIP) according to an embodiment of the present invention comprises the steps of: arranging a plurality of optical device chips, each positioned with its optical surface facing upward, in a desired arrangement on a carrier having a wafer shape and having a double-sided tape attached thereto; coating a photoresist to be photolithographed so as to cover the plurality of optical device chips; patterning the photoresist and removing the photoresist so as to leave only the patterned photoresist on the optical surface of the optical device; forming a molding layer by molding the upper portion of the wafer with a semiconductor encapsulating material; grinding the molding layer on the upper portion of the wafer so as to expose a portion of the patterned photoresist; removing a carrier from the wafer so as to expose a pad surface on which a terminal pad of the optical device chip is exposed; turning over the wafer from which the carrier has been removed, and then forming a redistribution layer and an external connection terminal on the pad surface on which the terminal pad of the optical device chip is exposed at wafer level; It is characterized by including a step of turning over the wafer on which the above-mentioned redistribution layer and external connection terminals are formed, and then removing the patterned photosensitive agent to obtain a wafer in which the optical surface of the optical element is opened; and a step of dicing the wafer in which the optical surface of the optical element is opened to singulate the wafer into individual packages.

[0026] In addition, a method for manufacturing an optical system-in-package (O-SIP) according to an embodiment of the present invention comprises the steps of: arranging a plurality of optical device chips, each positioned with its optical surface facing upward, in a desired arrangement on a carrier having a wafer shape and having a double-sided tape attached thereto; forming a molding layer by molding an upper portion of the wafer with a semiconductor encapsulating material; grinding the molding layer on the upper portion of the wafer so as to expose an upper surface of the optical device chip, thereby forming an optical coating layer that performs an optical function on the entire upper surface of the exposed upper surface of the optical device chip and the upper surface of the planarized molding layer; removing a carrier from the wafer so as to expose a pad surface where a terminal pad of the optical device chip is exposed; turning over the wafer from which the carrier has been removed, and forming a redistribution layer and an external connection terminal on the pad surface where the terminal pad of the optical device chip is exposed at wafer level; And it is characterized by including a step of sawing the wafer on which the rewiring layer and external connection terminal are formed to singulate the wafer into individual packages.

[0027] As described above, the optical system-in-package (O-SIP) according to the present invention may have a pad surface responsible for electrical connection of the optical element and an optical surface through which optical signals are input / output located on opposite surfaces.

[0028] To this end, we propose a method for opening a molded portion on an optical surface after the packaging process. This method can expose the entire surface of the chip, or only open a specific area.

[0029] Alternatively, if the optical surface is flat, the entire panel wafer can be ground after packaging to open the optical surface. This is a method of forming a new optical surface by further grinding the optical surface before packaging, and is a usable method because there is usually no terminal pattern on the substrate where the optical surface of the optical chip is located. In this case, since the surface may be damaged if there is a coating surface such as an AR coating (Anti-reflection coating) or a BPF (Band Pass Filter) coating, the optical coating surface can be formed later on the wafer after the packaging is complete.

[0030] In addition, according to the present invention, an optical system-in-package (O-SIP) can be packaged by including optical elements and electronic elements in the same mold body in a 2.5D packaging form.

[0031] Moreover, according to the present invention, the optical system-in-package (O-SIP) can have an assembled structure by stacking a package containing an optical element on top of another element (chip) in a 3D packaging form.

[0032] In this case, heat dissipation becomes difficult through both the electrical contact surface and the optical surface, which may result in poor heat dissipation characteristics. A heat dissipation structure to address this issue is also proposed in the present invention.

[0033] As described above, the present invention can provide an optical system-in-package (O-SIP) and a manufacturing method thereof, in which a pad surface on which electrical connection to an optical element is made and an optical surface on which an optical signal to the optical element is input and output are arranged on opposite surfaces.

[0034] In addition, the present invention can provide a manufacturing method for integrating a specific structure having an optical function or a mechanical function into a semiconductor package when the structure is present on an optical surface through which an optical signal passes.

[0035] The present invention enables integration of an optical element with a pad surface and an optical surface positioned opposite each other within a semiconductor package. This allows the optical element to be packaged and used alone, or multiple optical elements, or multiple optical elements and electronic elements, can be integrated together.

[0036] This allows for miniaturization and integration of components, resulting in miniaturization of the entire module and improved performance.

[0037] FIG. 1 is a cross-sectional view showing an optical system-in-package (O-SIP) having a micro lens array formed on an optical surface according to a first embodiment of the present invention.

[0038] FIGS. 2A to 2J are cross-sectional process diagrams each showing a manufacturing method for packaging the optical system-in-package (O-SIP) of FIG. 1 using a FOWLP (Fan Out Wafer Level Package) method.

[0039] FIG. 3 is a cross-sectional view showing an optical system-in-package (O-SIP) in which the optical surface is flat according to a second embodiment of the present invention.

[0040] FIGS. 4a to 4g are cross-sectional process diagrams each showing a manufacturing method for packaging the optical system-in-package (O-SIP) of FIG. 3 using a FOWLP (Fan Out Wafer Level Package) method.

[0041] FIGS. 5A and 5B are cross-sectional views showing the optical system-in-package (O-SIP) of the first and second embodiments, which includes an optical element in a 2.5D packaging form, and the optical system-in-package (O-SIP) in which electronic elements are packaged by including them in the same mold, according to the third and fourth embodiments of the present invention, respectively.

[0042] FIG. 6 is a cross-sectional view showing an optical system-in-package (O-SIP) having an assembled structure by stacking the optical system-in-package (O-SIP) of the first embodiment including an optical element on top of other elements in a 3D packaging form according to a fifth embodiment of the present invention.

[0043] FIG. 7 is a cross-sectional view showing an optical system-in-package (O-SIP) having a heat dissipation structure that dissipates heat in a lateral direction according to the fifth embodiment of FIG. 6, according to a sixth embodiment of the present invention.

[0044] Hereinafter, a preferred embodiment according to the present invention will be described with reference to the attached drawings.

[0045] In this process, the sizes and shapes of components depicted in the drawings may be exaggerated for clarity and convenience. Furthermore, terms specifically defined in consideration of the structure and operation of the present invention may vary depending on the intent or custom of the user or operator. Definitions of these terms should be based on the content throughout this specification.

[0046] The present invention proposes a structure for implementing an optical system-in-package (O-SIP) that includes a single optical element, multiple optical elements, or multiple optical elements and electronic elements within a package using optical FOWLP.

[0047] The above optical element can use various types of optical elements such as a VCSEL (Vertical Cavity Surface Emitting Laser) as a light-emitting element, a PD (Photodiode) as a light-receiving element, or a CIS (CMOS Image Sensor).

[0048] The above-mentioned optical elements can be used in, for example, optical transceivers that handle optical connections between servers, or optical modules that transmit image data between TVs and set-top boxes, or between VR glasses and graphics processing units. Another application is proximity sensors, TOF (Time of Flight) sensors, LIDARs, and other devices that include light-emitting elements to measure distances.

[0049] The above optical element can be used in an optical module that converts an optical signal into an electronic signal or an electronic signal into an optical signal, and converts the optical signal into a digital signal in a field that uses this for optical data transmission.

[0050] As another example, in the field of optical sensors, it can be used in image sensing devices that convert the characteristics of received light into image data or depth data.

[0051] The attached drawing 1 is a cross-sectional view of an optical system-in-package (O-SIP) having a micro lens array formed on an optical surface according to a first embodiment of the present invention.

[0052] Referring to FIG. 1, an optical system-in-package (O-SIP) having a micro lens array formed on an optical surface according to a first embodiment of the present invention is described.

[0053] An optical system-in-package (O-SIP) (100) according to a first embodiment of the present invention comprises an optical element (110) having an optical surface (112) on a first surface of an optical element body (118) through which an optical signal is input or output, and a pad surface (114) on which terminal pads (116a, 116b) are exposed on a second surface opposite to the optical surface (112) to form an electrical connection to the outside.

[0054] The above optical element (110) has a pad surface (114) arranged on the lower side of the optical element body (118) for electrical connection to the optical element (110) and an optical surface (112) arranged on the upper side of the optical element body (118) for inputting and outputting optical signals to the optical element (110). As a result, the pad surface (114) and the optical surface (112) are arranged on opposite sides of the optical element body (118).

[0055] In this case, the optical element (110) can be packaged and protected inside a mold body (150). The mold body (150) can be formed to surround the side surface of the optical element body (118) and the outer surface of the optical surface (112).

[0056] The above optical element (110) is arranged so that at least one pair of terminal pads (116a, 116b) are exposed to the pad surface (114), which is the lower surface of the optical element body (118).

[0057] The above optical element (110) can use various types of optical elements, such as, for example, a VCSEL (Vertical Cavity Surface Emitting Laser) as a light-emitting element, a PD (Photodiode) as a light-receiving element, and a CIS (CMOS Image Sensor).

[0058] In addition, the optical system-in-package (O-SIP) (100) is configured such that a pair of terminal pads (116a, 116b) of an optical element (110) are connected to the outside through an electrical redistribution layer (RDL) (120), and the redistribution layer (RDL) (120) may be connected to a conductive pattern (122) through a Cu pillar filled after a pair of terminal pads (116a, 116b) of an optical element (110) opens an insulating layer (124), or may be directly connected to a VIA of the redistribution layer (120).

[0059] In the above-mentioned redistribution layer (120), a plurality of external connection terminals (140) are connected to conductive patterns (122) embedded in an insulating layer (124). In this case, examples of the configuration of the external connection terminals (140) include BGA (Ball Grid Array), LGA (Land Grid Array), and micro bump.

[0060] The above optical element (110) chip is molded using an epoxy mold compound (EMC), which is a semiconductor encapsulating material, to form a mold body (150). In this case, an open structure is formed on the optical surface (112) of the optical element (110) chip so that it is not covered by the molding material. In this case, if there is a pattern or optical structure on the optical surface (112), it must be preserved as is and open.

[0061] FIG. 1 illustrates an example in which an optical structure, for example, a micro lens array (130), is formed on an optical surface (112) of an optical element (110). The micro lens array (130) serves to focus or collimate light, for example, when an optical signal is input and output to the optical element (110).

[0062] The optical element (110) having a plurality of micro lens arrays (130) formed on the optical surface (112) may be, for example, a CIS (CMOS Image Sensor). In addition, instead of the plurality of micro lens arrays (130), a single lens or a plurality of lens arrays may be formed on the optical surface (112) for focusing or collimating light when an optical signal is input or output, and the optical element (110) may be, for example, a VCSEL (Vertical Cavity Surface Emitting Laser) or a PD (Photodiode).

[0063] FIGS. 2A to 2J are cross-sectional process diagrams each showing a manufacturing method for packaging the optical system-in-package (O-SIP) (100) of FIG. 1 using a FOWLP (Fan Out Wafer Level Package) method.

[0064] First, as shown in Fig. 2a, a double-sided tape (210) is attached on a carrier (200), and then a plurality of optical element chips (110a-110c) are arranged in a desired arrangement on the double-sided tape (210) by a pick-and-place method. At this time, the terminal pads (116a, 116b) of the optical element chips (110a-110c) are positioned so that the exposed pad surface (114) faces downward and the optical surface (112) faces upward. In this case, it is preferable that the carrier (200) to which the double-sided tape (210) is attached has a wafer shape.

[0065] Next, as shown in Fig. 2b, a photoresist (PR) (220), which is a photosensitizer for photolithography, is coated to cover a plurality of optical element chips (110a-110c). At this time, the photoresist (PR) (220) may be applied as a photosensitizer material by a method such as spin coating or spray coating.

[0066] Additionally, instead of applying the above-mentioned photosensitizer, a polyimide tape or a thermal release film (TRF) may be attached in another way.

[0067] Thereafter, as shown in Fig. 2c, the photoresist (PR) (220) material applied using the known photolithography method can be patterned so that it remains only on the surface that needs to be open on the optical surface (112). At this time, the remaining portion (225) from the patterning can cover the entire optical element chip (110a-110c) or leave a single or multiple specific regions of the optical element chip (110a-110c).

[0068] Afterwards, as shown in Fig. 2d, a mold is formed using an epoxy mold compound (EMC), which is a semiconductor encapsulation material, and the photoresist (PR) (225), which is the remaining photosensitive material portion patterned in Fig. 2c, is also molded. At this time, the patterned photoresist (PR) (225) portion serves as a sacrificial layer that is subsequently removed.

[0069] Next, as shown in Fig. 2e, the upper part of the wafer is ground to expose the patterned photoresist (PR) (225) portion that serves as a sacrificial layer.

[0070] And, as shown in Fig. 2f, the carrier (200) is removed so that the pad surface (114) where the terminal pads (116a, 116b) of the optical element chip (110a-110c) are exposed is revealed.

[0071] After that, after turning the wafer over as shown in Fig. 2g, a redistribution layer (120) and an external connection terminal (140) are formed on the pad surface (114) where the terminal pads (116a, 116b) of the optical element chip (110a-110c) are exposed at the wafer level.

[0072] After that, as shown in FIG. 2h, the patterned photoresist (PR) (225) serving as a sacrificial layer is made to face upward, and then a process of removing the patterned photoresist (PR) (225) serving as a sacrificial layer is performed, thereby obtaining a wafer with an open optical surface (112) of an optical element (110) as shown in FIG. 2i.

[0073] Afterwards, by singulating the wafer into individual packages by dicing the wafer, a plurality of optical system-in-package (O-SIP) (100) are obtained as shown in FIG. 2j.

[0074] As described above, when the optical system-in-package (O-SIP) (100) according to the first embodiment is manufactured by packaging it in the FOWLP (Fan Out Wafer Level Package) manner, the external connection terminals (140) of the optical device chips (110a-110c) may be respectively arranged on the outside of the mold body (150).

[0075] However, when manufacturing the optical system-in-package (O-SIP) (100) according to the first embodiment by packaging it in a FIWLP (Fan In Wafer Level Package) manner, the external connection terminals (140) of the optical element chips (110a-110c) may be respectively placed on the inside of the mold body (150).

[0076] FIG. 3 is a cross-sectional view showing an optical system-in-package (O-SIP) in which the optical surface is flat according to a second embodiment of the present invention.

[0077] An optical system-in-package (O-SIP) (102) according to a second embodiment of the present invention comprises an optical element (105) packaged and protected inside a mold body (150). The optical element (105) has a pad surface (114) disposed on the lower side of the optical element body (118) for electrical connection to the optical element (110), and a flat optical surface (112) disposed on the upper side of the optical element body (118) for inputting and outputting optical signals to the optical element (105). As a result, the pad surface (114) and the optical surface (112) are disposed on opposite sides of the optical element body (118).

[0078] The above optical element (105) is arranged so that a pair of terminal pads (117a, 117b) are exposed to the pad surface (114), which is the lower surface of the optical element body (118).

[0079] In addition, the optical system-in-package (O-SIP) (102) is connected to the outside through an electrical redistribution layer (RDL) (120) in which a pair of terminal pads (117a, 117b) of an optical element (105) are connected to the outside, and the redistribution layer (RDL) (120) may be connected to a conductive pattern (122) through a Cu pillar filled after a pair of terminal pads (117a, 117b) of an optical element (105) opens an insulating layer (124), or may be directly connected to a VIA of the redistribution layer (120).

[0080] In the above-mentioned redistribution layer (120), an external connection terminal (140) is connected to a conductive pattern (122) embedded in an insulating layer (124). In this case, examples of the configuration of the external connection terminal (140) include BGA (Ball Grid Array), LGA (Land Grid Array), and micro bump.

[0081] The above optical element (105) is molded using an epoxy mold compound (EMC), which is a semiconductor encapsulating material, to form a mold body (150). The mold body (150) surrounds both sides of the optical element body (118), and the upper portion is set to coincide with the optical surface (112).

[0082] In this case, if the optical surface (112) is flat, the entire panel wafer may be ground after packaging to open the optical surface (112).

[0083] The above optical element (105) can use various types of optical elements, such as, for example, a VCSEL (Vertical Cavity Surface Emitting Laser) as a light-emitting element, a PD (Photodiode) as a light-receiving element, and a CIS (CMOS Image Sensor).

[0084] In this case, an optical coating layer (160) performing an optical function can be formed on the optical surface (112) of the optical element (105) and the flat surface of the upper portion of the mold body (150).

[0085] The optical coating layer (160) may be formed, for example, by an anti-reflection coating (AR) or a band pass filter (BPF) coating.

[0086] If the optical element (105) is a VCSEL (Vertical Cavity Surface Emitting Laser), a PD (Photodiode), or a CIS (CMOS Image Sensor), an anti-reflection (AR) coating may be applied as the optical coating layer (160), and if the optical element (105) is a PD (Photodiode) or a CIS (CMOS Image Sensor), a BPF (Band Pass Filter) coating may be applied as the optical coating layer (160).

[0087] The above optical coating layer (160) can be formed into a structure that performs various optical functions, such as a diffuser, when the optical element (105) is a VCSEL.

[0088] As described above, the optical system-in-package (O-SIP) (102) according to the second embodiment of the present invention can package the optical device (105) using the FOWLP or FIWLP process while maintaining the characteristics of the optical surface (112) of the optical device (105).

[0089] FIGS. 4a to 4g are cross-sectional process diagrams each showing a manufacturing method for packaging the optical system-in-package (O-SIP) of FIG. 3 using a FOWLP (Fan Out Wafer Level Package) method.

[0090] First, as shown in Fig. 4a, a double-sided tape (210) is attached on a carrier (200), and then a plurality of optical element chips (105a-105c) are arranged in a desired arrangement on the double-sided tape (210) using a pick-and-place method.

[0091] At this time, the terminal pads (117a, 117b) of the optical element chips (105a-105c) are positioned so that the exposed pad surface (114) faces downward and the optical surface (112) faces upward. In this case, it is preferable that the carrier (200) to which the double-sided tape (210) is attached has a wafer shape.

[0092] Next, as shown in Fig. 4b, a molding layer (230) is formed by molding a plurality of optical element chips (105a-105c) so that they are completely covered using an epoxy mold compound (EMC), which is a semiconductor encapsulation material, at the wafer level.

[0093] Thereafter, grinding is performed so that the upper surfaces of the optical element chips (105a-105c) can be exposed, thereby exposing the optical surface (112). In this case, the molding layer (230) and the upper portions of the optical element chips (105a-105c) may be removed together. In this case, the molding layer (230) forms a mold body (235) that maintains a wafer shape by interconnecting the side surfaces of the optical element chips (105a-105c) while protecting the side surfaces of the optical element chips (105a-105c) by removing the upper portion.

[0094] After this, an optical coating layer (160) can be additionally formed as shown in Fig. 4c, if necessary. The optical coating layer (160) can have functions such as a band pass filter (BPF) and an anti-reflection (AR) coating.

[0095] After this, as shown in FIG. 4d, the carrier (200) is removed to expose the pad surface (114) where the terminal pads (117a, 117b) of the optical element chip (105a-105c) are exposed, and then the wafer is turned over as shown in FIG. 4e.

[0096] Afterwards, as shown in Fig. 4f, a redistribution layer (120) and an external connection terminal (140) are formed on the pad surface (114) where the terminal pads (117a, 117b) of the optical element chip (105a-105c) are exposed at the wafer level.

[0097] Afterwards, by sawing the wafer, the wafer is singulated into individual packages, thereby obtaining a plurality of optical system-in-package (O-SIP) (102) as shown in FIG. 4g.

[0098] As described above, when manufacturing the optical system-in-package (O-SIP) (102) according to the second embodiment by packaging it using the FOWLP method, the external connection terminals (140) of the optical device chips (105a-105c) may be respectively placed on the outside of the mold body (150).

[0099] FIGS. 5A and 5B are cross-sectional views showing the optical system-in-package (O-SIP) of the first and second embodiments, which includes an optical element in a 2.5D packaging form, and the optical system-in-package (O-SIP) in which electronic elements are packaged by including them in the same mold, according to the third and fourth embodiments of the present invention, respectively.

[0100] Referring to FIG. 5a, an optical system-in-package (O-SIP) (300) according to a third embodiment of the present invention is packaged by including the optical system-in-package (O-SIP) (100) of the first embodiment including an optical element (110) and an electronic element (250) within one mold body (150) using the FOWLP method.

[0101] An optical system-in-package (O-SIP) (300) according to a third embodiment of the present invention comprises an optical element (110) and an electronic element (e.g., driver) (250) that drives or interfaces the optical element (110) within a single mold body (150), thereby converting an optical signal into an electronic signal or converting an electronic signal into an optical signal.

[0102] The optical system-in-package (O-SIP) (300) according to the third embodiment above has an optical element (110) and an electronic element (250) inside a mold body (150), and a redistribution layer (120) is formed on the pad surface (114) where the terminal pads (116a, 116b) of the optical element (110) and the terminal pads (250a, 250b) of the electronic element (250) are exposed, and an external connection terminal (140) is formed on the redistribution layer (120).

[0103] When the above optical element (110) is a VCSEL (Vertical Cavity Surface Emitting Laser) which is a light-emitting element, the electronic element (250) can act as a driver that drives the optical element (110) according to an electronic signal to be transmitted.

[0104] In addition, when the optical element (110) is a photodiode (PD) or CMOS image sensor (CIS), which is a light-receiving element, the electronic element (250) converts an optical signal incident through the optical element (110) into an electronic signal, and then amplifies the obtained electronic signal and converts it into a digital signal.

[0105] Referring to FIG. 5b, an optical system-in-package (O-SIP) (302) according to a fourth embodiment of the present invention is packaged by including the optical system-in-package (O-SIP) (102) of the second embodiment including an optical element (105) and an electronic element (250) within one mold body (150) using the FOWLP method.

[0106] An optical system-in-package (O-SIP) (302) according to a fourth embodiment of the present invention comprises an optical element (105) and an electronic element (e.g., driver) (250) that drives or interfaces the optical element (105) within a single mold body (150), thereby converting an optical signal into an electronic signal or converting an electronic signal into an optical signal.

[0107] The optical system-in-package (O-SIP) (302) according to the fourth embodiment above has an optical element (105) and an electronic element (250) inside a mold body (150), and a redistribution layer (120) is formed on the pad surface (114) where the terminal pads (117a, 117b) of the optical element (105) and the terminal pads (250a, 250b) of the electronic element (250) are exposed, and an external connection terminal (140) is formed on the redistribution layer (120).

[0108] In addition, the optical system-in-package (O-SIP) (302) is composed of an optical surface (112) of an optical element (105) and an upper surface of a mold body (150) that are flat surfaces, and an optical coating layer (160) such as an F (Band Pass Filter) or an anti-reflection (AR) coating can be formed on the upper flat surface.

[0109] When the above optical element (105) is a VCSEL (Vertical Cavity Surface Emitting Laser) which is a light-emitting element, the electronic element (250) can act as a driver that drives the optical element (110) according to an electronic signal to be transmitted.

[0110] In addition, when the optical element (105) is a photodiode (PD) or CMOS image sensor (CIS), which is a light-receiving element, the electronic element (250) converts an optical signal incident through the optical element (105) into an electronic signal, and then amplifies the obtained electronic signal and converts it into a digital signal.

[0111] When forming an optical system-in-package (O-SIP) (100, 102) as in the third and fourth embodiments described above, if an electronic element (250) is placed adjacent to an optical element (110, 105) inside a mold body (150) and packaged using the FOWLP method, the optical element (110, 105) and the electronic element (250) can be included in the same mold in a 2.5D packaging form.

[0112] As a result, the optical system-in-package (O-SIP) (300) according to the third embodiment of the present invention can achieve miniaturization and performance improvement of the entire optical module through miniaturization and integration of component sizes.

[0113] FIG. 6 is a cross-sectional view showing an optical system-in-package (O-SIP) having an assembled structure by stacking the optical system-in-package (O-SIP) of the first embodiment including an optical element on top of other elements in a 3D packaging form according to a fifth embodiment of the present invention.

[0114] Referring to FIG. 6, an optical system-in-package (O-SIP) (304) according to a fifth embodiment of the present invention illustrates another method of packaging the optical system-in-package (O-SIP) (100) of the first embodiment in a 3D packaging form together with, for example, an electronic device (250).

[0115] An optical system-in-package (O-SIP) (304) according to a fifth embodiment of the present invention is assembled by stacking the optical system-in-package (O-SIP) (100) of the first embodiment, which includes an optical element (110) on an electronic element (250) in a 3D packaging form.

[0116] In this case, the external connection terminal (140) of the optical element (110) is connected to the terminal pad (250a, 250b) of the electronic element (250) to complete the interconnection.

[0117] FIG. 7 is a cross-sectional view showing an optical system-in-package (O-SIP) (306) having a heat dissipation structure that dissipates heat in a lateral direction according to the fifth embodiment of the present invention, as shown in FIG. 6, according to a sixth embodiment of the present invention.

[0118] When the electronic device (250) and the optical device (110) are stacked in a three-dimensional form, such as the optical system-in-package (O-SIP) (304) according to the fifth embodiment, the operation of the optical device (110) chip may be affected when a heat dissipation structure is formed through the electronic device (250) chip located underneath. That is, heat dissipation may be difficult through the pad surface (114) or optical surface (112) of the optical device (110), which may result in poor characteristics.

[0119] Accordingly, the optical system-in-package (O-SIP) (306) according to the sixth embodiment of the present invention is a metal frame (180) for heat dissipation coupled in the lateral direction of the optical system-in-package (O-SIP) (304) to improve the heat dissipation characteristics of the optical system-in-package (O-SIP) (304) according to the fifth embodiment.

[0120] The above-mentioned heat-dissipating metal frame (180) is made of a metal material with good thermal conductivity, such as metal, and has a through hole provided in the central portion and a stepped portion formed in the lower inner portion, so as to have a structure that surrounds the electronic elements (250) and optical elements (110) accommodated in the stepped portion from the outside.

[0121] The side of the electronic element (250) is in close contact with the stepped portion formed on the lower inner circumference of the heat-dissipating metal frame (180) so that heat generated from the electronic element (250) can be dissipated to the heat-dissipating metal frame (180), and a heat-dissipating filler (190) having good thermal conductivity is filled between the mold body (150) of the optical system-in-package (O-SIP) (304) and the inner circumference of the heat-dissipating metal frame (180) to implement a heat-dissipating structure that dissipates heat in the lateral direction.

[0122] The above heat dissipation filler (190) may use thermal grease or silver paste.

[0123] As illustrated in FIGS. 6 and 7, the optical system-in-package (O-SIP) (304, 306) according to the fifth and sixth embodiments of the present invention, in which the electronic element (250) and the optical element (110) are assembled in a 3D packaging form, has a structure in which the length is shortened and the height is increased compared to the optical system-in-package (O-SIP) (300, 302) of the 2.5D packaging structure in which the electronic element (250) and the optical element (110) are adjacently arranged as illustrated in FIGS. 5A and 5B.

[0124] Although the present invention has been described and illustrated with specific preferred embodiments as examples, the present invention is not limited to the above embodiments, and various changes and modifications may be made by a person having ordinary skill in the art to which the invention pertains within a scope that does not depart from the spirit of the present invention.

[0125] The present invention can be applied to implementing an optical system-in-package (O-SIP), which integrates a system using optical components into a single package. This can be widely used in the optical communications and optical sensor industries. For optical communications, it can be used for communication between servers within data centers and for optical transceivers for 5G and 6G communication networks.

[0126] In addition, since miniaturization and integration are implemented within the package, it can also be used for on-board optical communication and chip-to-chip optical communication.

Claims

1. An optical element having an optical surface on the first surface of the optical element body through which an optical signal is input or output, and a pad surface on the second surface opposite to the optical surface through which a terminal pad is exposed and an electrical connection to the outside is made; A mold body surrounding the outer side of the above optical element body; and An optical system-in-package (O-SIP) including a redistribution layer formed on a pad surface of the optical device body to electrically connect a terminal pad of the optical device and an external connection terminal.

2. In paragraph 1, It further includes a plurality of micro lens arrays formed on the optical surface to focus or collimate light when an optical signal is input or output, The above optical device is an optical system-in-package (O-SIP) that is a CMOS Image Sensor (CIS).

3. In paragraph 1, Further comprising a single lens or a plurality of lens arrays formed on the optical surface for focusing or collimating light when an optical signal is input or output, The above optical device is an optical system-in-package (O-SIP) that is a Vertical Cavity Surface Emitting Laser (VCSEL) or a Photodiode (PD).

4. In paragraph 1, The upper part of the above mold body is set as a flat surface to match the above optical surface, An optical system-in-package (O-SIP) further comprising an optical coating layer performing an optical function on the above flat surface.

5. In paragraph 4, When the optical element is any one of a VCSEL (Vertical Cavity Surface Emitting Laser), a PD (Photodiode), and a CIS (CMOS Image Sensor), the optical coating layer is an optical system-in-package (O-SIP) that is an anti-reflection (AR) coating.

6. In paragraph 4, When the above optical element is a PD (Photodiode) or CIS (CMOS Image Sensor), the optical coating layer is an optical system-in-package (O-SIP) that is a BPF (Band Pass Filter) coating.

7. In paragraph 4, When the above optical element is a VCSEL (Vertical Cavity Surface Emitting Laser), the optical coating layer is an optical system-in-package (O-SIP) that is a diffuser.

8. In paragraph 1, An optical system-in-package (O-SIP) further comprising an electronic component embedded within the mold body and driving or interfacing the optical component.

9. In paragraph 8, The above mold body is an optical system-in-package (O-SIP) in which the optical surface of the optical element is open so that the molding material does not cover it.

10. In paragraph 8, The upper part of the above mold body is set as a flat surface to match the above optical surface, An optical system-in-package (O-SIP) further comprising an optical coating layer performing an optical function on the above flat surface.

11. In paragraph 8, If the above optical element is a photodetector, the electronic element is an optical system-in-package (O-SIP) that converts an optical signal incident through the optical element into an electronic signal, amplifies the obtained electronic signal, and converts it into a digital signal.

12. In paragraph 1, An optical system-in-package (O-SIP) further comprising an electronic component that drives or interfaces the optical component and is coupled to the lower portion of the optical system-in-package (O-SIP) so that the external connection terminal is connected to the terminal pad exposed on the upper surface.

13. In paragraph 12, A metal frame for heat dissipation, in which a through hole is provided in the central portion and the side of the electronic element is in close contact with a stepped portion formed in the lower inner portion to dissipate heat generated from the electronic element; and An optical system-in-package (O-SIP) further comprising a heat-dissipating filler filled between the mold body and the inner portion of the heat-dissipating metal frame to transfer heat generated from the optical element to the heat-dissipating metal frame in the lateral direction.

14. A step of arranging a plurality of optical element chips, each positioned with its optical surface facing upward, in a desired arrangement on a carrier formed in the form of a wafer and having a double-sided tape attached thereto; A step of coating a photosensitive material that is used for photolithography to cover a plurality of optical element chips; A step of patterning the above photosensitive agent and removing the patterned photosensitive agent, leaving only the patterned photosensitive agent on the optical surface of the optical element; A step of forming a molding layer by molding the upper part of the wafer with a semiconductor bag material; A step of grinding the molding layer on the upper part of the wafer so that the patterned photosensitive material portion is exposed; A step of removing a carrier from the wafer so that the pad surface on which the terminal pad of the optical element chip is exposed is exposed; A step of forming a redistribution layer and an external connection terminal on the pad surface where the terminal pad of the optical element chip is exposed at the wafer level after turning over the wafer from which the carrier has been removed; A step of turning over the wafer on which the above-mentioned redistribution layer and external connection terminals are formed, and then removing the patterned photosensitive agent to obtain a wafer with an open optical surface of the optical element; and A method for manufacturing an optical system-in-package (O-SIP), comprising: a step of dicing a wafer with an open optical surface of the optical element and singulating the wafer into individual packages.

15. A step of arranging a plurality of optical element chips, each positioned with its optical surface facing upward, in a desired arrangement on a carrier formed in the form of a wafer and having a double-sided tape attached thereto; A step of forming a molding layer by molding the upper part of the wafer with a semiconductor bag material; A step of grinding the molding layer on the upper side of the wafer so that the upper side of the optical element chip is exposed, thereby forming an optical coating layer that performs an optical function on the entire upper side of the exposed upper side of the optical element chip and the upper side of the flattened molding layer; A step of removing a carrier from the wafer so that the pad surface on which the terminal pad of the optical element chip is exposed is exposed; After turning over the wafer from which the carrier has been removed, a step of forming a redistribution layer and an external connection terminal on the pad surface where the terminal pad of the optical device chip is exposed at the wafer level; and A method for manufacturing an optical system-in-package (O-SIP), comprising the step of sawing a wafer on which the above-mentioned redistribution layer and external connection terminals are formed and singulating the wafer into individual packages.

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