TWI903945B - Laser package structure - Google Patents

Abstract

A laser package structure is provided. The package structure includes a substrate, a laser chip arranged on a first face of the substrate, a housing arranged on the first face of the substrate and surrounding the laser chip, the housing having a height higher than the thickness of the laser chip, and an optical element arranged on the housing. The housing includes an electrically conductive structure vertically extending through the sidewall of the housing. The optical element is electrically connected to the substrate through the electrically conductive structure.

Description

Laser Packaging Structure

This invention relates to a laser packaging structure, and more particularly to a packaging structure for a vertical cavity surface-emitting laser (VCSEL) element.

Referring to Figure 1, the familiar laser chip 110, such as a vertical cavity surface-emitting laser (VCSEL) device, is first die-bonded onto a ceramic substrate 100 during packaging. After wire bonding to form wires 120, spacers 130 are provided around the laser chip 110 to form a partition space 140, which serves as an air layer. Next, the single-chip packaging process is completed by covering it with optical element 150, forming a laser chip package structure 10 for subsequent connection to an external circuit board. The optical element 150 includes a microlens array (MLA) or a diffraction optical element (DOE), which can convert the light beam emitted from the laser chip 110 into a uniform surface light source, an array of point light sources, or irregularly distributed point light sources.

Referring to Figure 2, to further consider the eye-safety mechanism of the laser chip in module applications, a photodiode 220 is provided within the laser chip package structure 20. Wire bonding is used to form lines 210 and 215 within the package structure 20, respectively connecting the laser chip 110 and the photodiode 220. When the laser chip 110 emits laser light that passes through the upper optical element 150, the laser light is converted into a uniform surface light source, an array of point light sources, or a scattered point light source. When this light hits an external object, it is reflected back as reflected light. The photodiode 220 can absorb this reflected light to monitor the function of the optical element 150. When the optical element 150 is damaged or deteriorated, the angle of the reflected light changes, causing the photodiode 220 to be unable to receive the reflected light. This indicates that the optical element 150 is damaged, thus stopping the laser chip 110 from continuing to operate.

This invention provides a laser packaging structure, which is a chip-scale package (CSP) fabricated using a wafer-level package (WLP) process. This improves the packaging yield of laser chips and reduces their package structure size.

This invention provides a laser packaging structure that utilizes an electrically conductive support to offer a novel protection mechanism for laser chips in module applications. This reduces module size and significantly lowers the risk of module failure due to external circuit breakage, while also saving manufacturing costs.

According to the present invention, a laser packaging structure is provided, comprising: a substrate; a laser chip disposed on a first surface of the substrate; a support disposed on the first surface and surrounding the laser chip, wherein the height of the support is greater than the thickness of the laser chip, and the support includes an electrically conductive structure perpendicularly penetrating therethrough; and an optical element disposed on the support, wherein the optical element is electrically connected to the substrate via the electrically conductive structure.

According to the present invention, a laser packaging structure is provided, comprising: a laser chip, the laser chip including a first conductive structure and a second conductive structure disposed on a first surface thereon; an adhesive layer surrounding at least four sides of the laser chip; a spacer correspondingly disposed on the adhesive layer and surrounding the laser chip; and an optical element disposed on the spacer facing a second surface of the laser chip, the second surface being opposite to the first surface; wherein the laser chip is electrically connected to an external circuit board via the first conductive structure and the second conductive structure, and wherein the spacer is respectively connected to the optical element and the adhesive layer via corresponding adhesive layers.

10: Laser Packaging Structure

100: Ceramic substrate

110: Laser Chip

120: Route

130: Spacer

140: Separating Spaces

150: Optical Components

20A: Laser Packaging Structure

20B: Laser Packaging Structure

210: Electrical connection structure

220: Photodiode

230: Line

30: Packaging Structure

32: External Circuit Board

34: Tin plaster

310: Laser Chip

310A: Surface

310B: Surface

312: First Conductor Structure

314: Second Conductive Structure

320: Adhesive layer

320’: Encapsulation material

330: Spacer

340: Internal cavity

350: Optical Components

352: Glass layer

354: Graphical adhesive layer

354’: Graphical adhesive layer

356:Conductive line layer

358A: First Conductor Circuit Section

358B: Second Conductor Circuit Section

360: Adhesion Layer

362: Adhesive Layer

370: Wiring Structure

40: Packaging Structure

420: Adhesive layer

420A: Through section

430: Spacer

440: Internal cavity

442: Electrically Conductive Structure

460: Adhesive layer

462: Adhesive layer

462A: Positive

462B: Negative

502: Adhesive tape

504: Adhesive Layer

506: Glass Plate

522: Protective Layer

70: Packaging Structure

700:Substrate

700A: Surface

702A, 702B: First electrical conduction post

704A, 704B: Second electrical conduction post

710: Laser Chip

730: Bracket

730A: Sidewall

732: Positioning Department

732A: Space

732B: Bevel

732C: Bottom

732D: Connecting Spaces

734: Guide groove

736: Sealant layer

738: Secondary Guide Channel

740: Internal cavity

742: Electrically Conductive Structure

750: Optical Components

760:Conductive structure

H: Height of the bracket

t: wafer thickness

W: Width of the positioning section

L: Length of the positioning section

To further understand the features and technical content of this invention, please refer to the following detailed description of embodiments of this invention and the accompanying drawings. However, the detailed description and accompanying drawings are provided for reference and illustration only and are not intended to limit the invention; wherein: Figure 1 is a schematic cross-sectional view of a conventional laser packaging structure.

Figure 2 is a cross-sectional schematic diagram of a conventional laser packaging structure with a protective mechanism.

Figure 3 is a schematic cross-sectional view of a laser packaging structure according to one embodiment of the present invention.

Figures 4A to 4F are cross-sectional schematic diagrams illustrating the manufacturing process of a laser packaging structure according to one embodiment of the present invention.

Figures 5A to 5C are cross-sectional schematic diagrams illustrating the manufacturing process of a laser packaging structure according to one embodiment of the present invention.

Figures 6A and 6B are cross-sectional schematic diagrams illustrating the manufacturing process of a laser packaging structure according to one embodiment of the present invention.

Figures 7A and 7B are cross-sectional schematic diagrams illustrating the manufacturing process of a laser packaging structure according to one embodiment of the present invention.

Figure 8 is a schematic cross-sectional view of a laser packaging structure according to one embodiment of the present invention.

Figures 9A and 9B are schematic cross-sectional views of a laser packaging structure according to one embodiment and variations of the present invention.

Figures 10A and 10B are top and cross-sectional schematic diagrams of the penetrating portion of the adhesive layer in an embodiment of the present invention.

Figures 11A to 11G are cross-sectional and top-view schematic diagrams of an optical element according to one embodiment of the present invention.

Figure 12 is a schematic cross-sectional view of a laser packaging structure according to one embodiment of the present invention.

Figures 13A to 13C are cross-sectional views of the support shown by line A-A' in Figure 14A.

Figures 14A to 14D are top views of the support structure in various embodiments of the present invention.

The following description, with reference to the drawings and illustrative examples, illustrates the concepts of this invention. Similar or identical parts in the drawings and description use the same component symbols. Furthermore, the drawings are created for ease of understanding; the thickness and shape of each layer in the drawings do not represent the actual dimensions or proportions of the components.

Please refer to Figure 3, which is a cross-sectional schematic diagram of a laser packaging structure according to a first embodiment of the present invention. The packaging structure 30 of this embodiment is a laser packaging structure manufactured by a wafer-level packaging process, which includes: a laser chip 310 for emitting a laser light, the laser chip 310 including a first conductive structure 312 and a second conductive structure 314 located on its surface 310B, and the four sides of the laser chip 310 being surrounded by an adhesive layer 320. A spacer 330 is correspondingly provided on the adhesive layer 320, and the spacer 330 surrounds the laser chip 310 to form a space, which forms an inner cavity 340 of the packaging structure 30 after packaging is completed. An optical element 350 is covered on the spacer 330. The optical element 350 is disposed on the spacer 330 facing a surface 310A of the laser chip 310, with surface 310A and surface 310B of the laser chip 310 opposite each other. The optical element 350 includes a microlens array (MLA) or a diffraction optical element (DOE), which can convert the light beam emitted from the laser chip 310 into a uniform surface light source, an array of point light sources, or an irregularly distributed point light source. The laser chip 310 within the cavity 340 of the package structure 30 is electrically connected to an external circuit board 32 via its first conductive structure 312 and second conductive structure 314. The spacer 330 is connected to the optical element 350 and the adhesive layer 320 via corresponding adhesive layers 360 and 362, respectively. In this embodiment, the adhesive layers 360 and 362 can be made of a general non-conductive adhesive, used only to fix the spacer 330 to the optical element 350 and the underlying adhesive layer 320, respectively. In this embodiment, when a current from the external circuit board 32 drives the laser chip 310 through the first conductive structure 312 and the second conductive structure 314, the laser chip 310 can emit laser light that passes through the optical element 350. The optical element 350 may include a conductive layer (see Figure 11A below), wherein the conductive layer material includes a transparent conductive material, such as ITO (Indium Tin Oxide), to avoid blocking the light beam emitted by the laser chip 310. The conductive layer is used to detect the operation of the optical element 350. When the optical element 350 is operating normally, the conductive layer will conduct to allow current to flow; when the optical element 350 is damaged, the conductive layer may also be damaged, resulting in a change in resistance or an open circuit. The external circuit board 32 has a feedback circuit (not shown) electrically connected to the laser chip 310, and is electrically connected to the conductive layer of the optical element 350 and the feedback circuit on the external circuit board 32 via a wiring structure 370. In one embodiment, the feedback circuit comprises a resistance sensor and a circuit breaker. Therefore, when the optical element 350 is damaged, the conductive layer within the optical element 350 may also be damaged, resulting in a change in resistance or an open circuit. At this time, the feedback circuit electrically connected to the conductive layer, through its included resistance sensor, can immediately detect the change in resistance of the conductive layer on the optical element 350, and can use its circuit breaker to stop the laser chip 310 from emitting laser light.

Please refer to Figures 4A to 4F, which are schematic cross-sectional views illustrating the structure of each step in the fabrication process of the laser chip package structure 30 according to one embodiment of the present invention.

In this embodiment, the wafer-level package structure of the VCSEL device is fabricated using a wafer-level packaging process. First, as shown in Figure 4A, the laser chip 310 is laid on tape 502. The laser chip 310 has a first conductive structure 312 and a second conductive structure 314. Next, as shown in Figure 4B, the laid-up structure is transferred. The structure is inverted onto a glass sheet 506 coated with an adhesive layer 504, and the tape 502 is removed to expose the surface 310A of the laser chip 310.

Next, using methods such as brushing, encapsulating adhesive 320' is filled or poured into the formed structure, so that the encapsulating adhesive 320' covers each laser chip 310, as shown in Figure 4C. Then, the encapsulating adhesive 320' covering the surface of the laser chip 310 is removed by methods such as grinding, polishing, and/or sandblasting, forming the structure shown in Figure 4D; wherein, after partial removal of the encapsulating adhesive 320', an adhesive layer 320 is formed surrounding the four sides of the laser chip 310 and coplanar with the surface of the laser chip 310.

Next, using wafer bonding, the spacer 330 and the optical element 350 are connected to the structure shown in Figure 4D, forming the structure shown in Figure 4E. In this example, the encapsulating material 320' has been polished into a coplanar layer 320 surrounding the four sides of the laser wafer 310. The spacer 330 is correspondingly connected to the encapsulating layer 320 and correspondingly surrounds the four sides of the laser wafer 310, forming the inner cavity 340 or air layer of the encapsulation structure.

Next, the adhesive tape layer 504 and the glass sheet 506 are removed, forming the structure shown in Figure 4F.

Next, the structure shown in Figure 4F is cut into several independent structures, forming the laser chip package structure 30 of this invention shown in Figure 3. The package structure 30 is then connected to the external circuit board 32 via an external wiring structure 370, thus forming the structure shown in Figure 3.

Alternatively, when forming the adhesive layer 320 in the structure shown in Figure 4D, the adhesive layer 320 can be formed by brushing adhesive onto a steel plate in the structure shown in Figure 4B, filling the gaps between the laser wafers 310 with encapsulating adhesive. The steel plate is configured to shield the laser wafers 310, preventing the encapsulating adhesive from contacting the surface 310A of the laser wafers 310.

Figures 5A-5C show the structure and process of another embodiment. As shown in Figure 5A, after a protective layer 522 (e.g., a dry film protective layer) is provided on the surface 310A of the laser wafer 310, the position to be filled with encapsulating material is opened by exposure and development, and encapsulating material is filled to form an adhesive layer 320, forming the structure shown in Figure 5A. Next, a polishing process is performed to remove the overflowing encapsulating material on the protective layer 522, and after removing the protective layer 522, the optical element 350 and the adhesive layer 320 are connected by alignment bonding. Subsequently, the adhesive tape layer 504 and the glass sheet 506 are removed to form the structure shown in Figure 5B. Next, a dicing process is performed to cut the structure shown in Figure 5B into independent structures, forming the laser chip package structure 30A of this invention, as shown in Figure 5C.

Figures 6A-6B illustrate the structure and process of another embodiment. Following the encapsulation material 320' structure shown in Figure 4C, depending on the actual application requirements, the encapsulation material 320' on the surface 310A of the laser chip 310 is not flattened or removed. Instead, the encapsulation material is retained as an adhesive layer 320. The spacer 330 and the optical element 350 are connected to the adhesive layer 320. After removing the tape layer 504 and the glass sheet 506, the structure shown in Figure 6A is formed. Then, the structure shown in Figure 6A is cut to form the laser chip encapsulation structure 30B of the present invention, as shown in Figure 6B.

Figures 7A and 7B illustrate the structure and fabrication process of another embodiment. Following the encapsulation material 320' structure shown in Figure 4C, the encapsulation material covering the surface 310A of the laser chip 310 is patterned to form a patterned encapsulation material layer 354', such as a microlens array (MLA) or a diffraction optical element (DOE), providing optical effects different from the patterned encapsulation material layer 354 in the optical element 350, such as shaping the light beam emitted from the laser chip 310 into a uniform surface light source, an array of point light sources, or an irregular point light source, as shown in Figure 7A. The structure shown in Figure 7A is then cut to form the laser chip encapsulation structure 30C of the present invention, as shown in Figure 7B.

Figure 8 shows another embodiment of the structure, in which another patterned adhesive layer 354' can be formed on the outer surface of the optical element 350 (i.e., the side without the patterned adhesive layer 354). This provides optical effects different from and/or different from the patterned adhesive layer 354' on the surface 310A of the laser chip 310, such as shaping the light beam emitted by the laser chip 310 into a uniform surface light source, an array of point light sources, or an irregular point light source. After dicing, this forms the laser chip package structure 30D as shown in Figure 8.

As shown in Figures 9A and 9B, according to another embodiment of the present invention, the spacer in the package structure can also be formed to cover an electrically conductive structure passing through it, directly supplying electrical conductivity. Please refer to Figures 9A and 9B, which are schematic cross-sectional views of laser package structures 40A and 40B according to an embodiment and variations of the present invention. Package structures 40A and 40B can be manufactured using the same or similar processes and have a similar structure to the aforementioned package structure 30. However, the difference between them and package structure 30 is that, in this embodiment, the spacer 430 that forms the inner cavity 440 around the laser chip 310 includes an electrically conductive structure 442 passing through it; the conductive layer 460 connects the conductive line layer of the optical element 350 and the electrically conductive structure 442; a penetrating portion 420A corresponding to the electrically conductive structure 442 is also formed in the adhesive layer 420, and conductive adhesive is filled into the penetrating portion 420A to form a conductive layer 462 connected to the electrically conductive structure 442. In this embodiment, the materials of the electrically conductive structure 442 and the conductive layers 460, 462A, and 462B can be conductive adhesives, such as silver paste, solder paste, or self-assembly anisotropic conductive paste (SAP), or electroplated metal materials, such as gold, silver, copper, and alloys thereof. In this embodiment, the conductive structures 312 and 314 of the laser chip 310 and the conductive layers 462A and 462B of the package structure are directly connected to the external circuit board 32 as positive and negative electrodes, respectively, forming the package structure 40A as shown in Figure 9A. Alternatively, conductive layers 462A and 462B can be further connected to the external circuit board 32 by, for example, solder paste 34, forming a package structure 40B as shown in Figure 9B. That is, in this embodiment, the optical element 350 of the package structures 40A and 40B is electrically connected to the external circuit board 32 by conductive layer 460, electrical conduction structure 442, and conductive layers 462A and 462B. In the embodiment shown in Figures 9A and 9B, a penetrating portion 420A must be formed in the adhesive layer 420, the position of which corresponds to the position of the electrical conduction structure 442 covered in the spacer 430 and the electrode position of the optical element 350. Regarding the formation of the through portion in the adhesive layer (as shown in Figures 9A and 9B, the through portion 420A) can be formed by shielding the wafer and the position corresponding to the electrode of the optical element 350 when applying the encapsulating adhesive by brushing it onto a stencil during the stencil construction, thus preventing the encapsulating adhesive from filling in it, thereby forming the through portion 420A of the adhesive layer, forming the structure shown in Figures 10A (top view schematic diagram) and 10B (cross-sectional view schematic diagram). After filling the through portion 420A with a conductive adhesive material to form a conductive layer 462, the spacer 430 having an electrically conductive structure 442 and the optical element 350 are connected to the formed structure, thereby forming the laser wafer packaging structures 40A and 40B as shown in Figures 9A and 9B. As explained above, in this embodiment, the optical components 350 of packages 40A and 40B are electrically connected to the external circuit board 32 via an electrical conduction structure 442, thus eliminating the need for external wiring connections to the circuit board.

In this invention, the encapsulating adhesive and/or conductive adhesive can be applied by brushing adhesive onto a stencil, thereby forming the adhesive layer and conductive layer in the encapsulation structure respectively. In this way, in addition to the stable control of the amount of adhesive, the output of the process (Units Per Hour, UPH) can also be increased, which is beneficial to the reduction of process costs. Furthermore, since a certain pressure is applied during the adhesive application process to fill the adhesive material, space can be reserved around the laser chip 310 for conductive adhesive materials (such as solder paste) to fill. During subsequent surface mounting technology (SMT), the conductive layer 462 (as shown in Figure 9A) or the solder paste 34 (as shown in Figure 9B) will connect with the electrodes (not shown) of the external circuit board 32 to form a conductive circuit.

Please refer to Figures 11A and 11B, which are schematic cross-sectional views and top views further illustrating the optical element 350 according to one embodiment of the present invention. Figure 11A schematically illustrates the cross-sectional structure shown along the arrow direction B of line A-A' in Figure 11B. In this embodiment, the optical element 350 includes a glass layer 352, a patterned adhesive layer 354 located on the glass layer 352 and facing the laser chip side, and a conductive line layer 356 located between the glass layer 352 and the patterned adhesive layer 354. As seen in Figure 11B, the conductive layer 356 is further connected to a first conductive line portion 358A and a second conductive line portion 358B located in the surrounding area of the glass layer 352. The first conductive line portion 358A and the second conductive line portion 358B are not spatially connected to each other, but are electrically connected through the conductive layer 356, and are respectively located on opposite sides of each other in the surrounding area.

In one embodiment, the first conductive line portion 358A and the second conductive line portion 358B may be formed by electroplating or coating with a conductive material, which may include metals such as copper, silver, gold, and tin. Furthermore, as seen in Figure 11B, the first conductive line portion 358A and the second conductive line portion 358B are designed to be linear (as shown in Figure 11B), circular (as shown in Figure 11C), square (as shown in Figure 11D), L-shaped (as shown in Figure 11E), U-shaped (as shown in Figure 11F), or one of the aforementioned combinations of shapes. Furthermore, the number of the first conductive line portion 358A and the second conductive line portion 358B is not limited to one each; a plurality of the first conductive line portion 358A and the second conductive line portion 358B can be provided on opposite sides of the glass layer 352 (as shown in Figure 11G).

In this invention, the optical element 350 includes, for example, but not limited to, a microlens array, indium tin oxide (ITO) glass with conductive lines, and a diffraction optical element (DOE). In one embodiment, the optical element 350 can also be a composite optical element, i.e., the patterned adhesive layer 354 contains different patterns to form different lens structures, such as a microlens array (MLA) and a diffraction optical element (DOE), simultaneously converting the laser beam into different light patterns, such as a surface light source, an array of point light sources, and irregularly distributed point light sources.

In the above embodiment, the laser chip 310 is a flip-chip type chip. The adhesive layers 320 and 420 and the encapsulating material 320' can be made of transparent or opaque materials, such as epoxy resin or silicone. The spacers 330 and 430 can be made of materials such as glass, ceramic, or plastics that can be formed using 3D printing or molding.

Please refer to Figure 12, which is a cross-sectional schematic diagram of a laser packaging structure according to an embodiment of the present invention. The packaging structure 70 according to the present embodiment includes: a substrate 700, and a laser chip 710 disposed on a surface 700A of the substrate 700. The substrate 700 may be a ceramic substrate, and first electrical conductive posts 702A and 702B and second electrical conductive posts 704A and 704B are formed in the substrate 700, wherein the first electrical conductive posts 702A and 702B are connected to the laser chip 710, and respectively serve as positive and negative electrodes to provide the laser chip 710 with external electrical connections. The package structure 70 includes a support 730 disposed on surface 700A and surrounding laser wafer 710. The height H of the support 730 is greater than the thickness t of laser wafer 710, thereby providing an inner cavity 740. The inner cavity 740 serves as a vapor chamber for the package structure 70 (the vapor chamber can be filled with inert gas or air, or it can be evacuated). The package structure 70 includes an optical element 750, which is connected to the support 730 via a conductive structure 760 formed by conductive adhesive applied to the support 730. In this embodiment, the optical element 750 is an ITO optical element with conductive lines.

According to the present invention, the support 730 is formed by means such as plastic injection molding, molding, or 3D printing, and is formed to include an electrically conductive structure 742 perpendicularly penetrating it, allowing the optical element 750 to be electrically connected, respectively, to the second electrically conductive posts 704A and 704B penetrating the substrate 700 via this electrically conductive structure 742 as positive and negative electrodes, respectively. The conductive adhesive of the conductive structure 760 can be made of materials such as silver paste, solder paste, anisotropic conductive adhesive, or other conductive materials.

According to the present invention, the bracket 730 is formed by plastic injection molding, molding, or 3D printing. The bracket 730 covers the electrically conductive structure 742 and is bonded to the optical element 750 by applying a conductive adhesive such as silver paste, solder paste, or anisotropic conductive adhesive. The optical element 750 is electrically connected to the second electrically conductive posts 704A and 704B of the underlying substrate 700 through the conductive structure 760 and the electrically conductive structure 742 inside the bracket 730. Alternatively, the support 730 can be formed using Laser Direct Structuring (LDS) technology, followed by electroplating or chemical plating to form a metal plating layer, thereby creating a circuit or conductive structure 760 for electrical connection to the optical element 750 and the bottom substrate 700.

According to the present invention, the conductive structure 760 applied to the bracket 730 can be selectively formed as a straight line, circle, square, L-shape, U-shape, or a combination of the aforementioned shapes. Furthermore, the number of conductive structures on each side of the bracket 730 is not limited to one; multiple conductive structures can be provided on opposite sides. The various top-view shapes of the aforementioned conductive structures correspond to the descriptions of the top-view schematic diagrams in Figures 11B to 11G, respectively.

The optical element 750 may have a similar configuration to that shown in Figure 11A, and will not be described in detail here.

Please refer to Figures 13A to 13C and Figures 14A to 14D, which illustrate different designs of the support in embodiments of the present invention using sectional and top views, respectively.

Figures 13A and 13B are cross-sectional views of the support shown along line A-A' in Figure 14A, pointing in the direction of arrow B, illustrating an embodiment of the support of the present invention. As shown in Figure 13A, according to the present invention, the support 730 is formed as a structure consisting of four sidewalls surrounding the laser chip, with the aforementioned electrical conductive structure (not shown) penetrating through the sidewalls.

As shown in Figure 13A, a positioning portion 732 is formed on the top of the support 730 (opposite to the side connected to the bottom substrate) for receiving and maintaining the position of the optical element 750. In this embodiment, the positioning portion 732 is a recess having a bottom 732C for placing the optical element 750 and a slope 732B that tapers downwards from the support 730 connecting to the bottom 732C. The contour of the positioning portion 732 corresponds to and is slightly larger than the optical element 750, and a sealant layer 736 is filled in the gap 732A between the slope 732B and the optical element 750. The slope 732B facilitates filling the positioning portion 732 with adhesive material (e.g., sealant layer 736) to seal the inner cavity 740 of the encapsulation structure.

In one embodiment, as shown in Figure 13B, in addition to the positioning portion 732, the top of the bracket 730 may further have a guide groove 734 extending from the bottom 732C downwards from the bracket 730 for filling with conductive adhesive (e.g., silver paste, solder paste, anisotropic conductive adhesive, etc.). The optical element 750 is electrically connected to the electrical conduction structure (not shown) within the bracket 730 via this conductive structure 760. As shown in Figure 13B, after the optical element 750 is placed at the bottom 732C of the positioning portion 732, the gap 732A formed between the optical element 750 and the inclined surface 732B of the positioning portion 732 is isolated from and does not communicate with the guide groove 734 filled with conductive adhesive. In this embodiment, the gap 732A between the optical element 750 and the inclined surface 732B is for filling with adhesive material, such as transparent adhesive, to form a sealing layer 736 between the optical element 750 and the support 730, thereby sealing the inner cavity 740 of the encapsulation structure.

Alternatively, as shown in Figure 13C, the guide groove 734 and the positioning portion 732 can also be designed to form a connecting space 732D after the optical element 750 is positioned. In this embodiment, only one filling is performed, whereby conductive adhesive (e.g., silver paste) is filled into the positioning portion 732 and the guide groove 734 of the bracket 730 to form a conductive structure 760.

Referring also to Figure 14A, which is a top view showing the cross-sectional structure as shown in Figures 13A and 13B, in the bracket 730 shown in Figure 13A, the shape of the positioning portion 732 corresponds to and is slightly larger than the optical element 750. A gap 732A is formed between the optical element 750 and the inclined surface 732B of the positioning portion 732 for filling with adhesive to form a sealing layer 736. As seen in Figure 14A, the optical element 750 is positioned in the positioning portion 732 of the bracket 730, and the sealing layer 736 surrounds the optical element 750 to block moisture and protect the optical element 750. Additionally, in the bracket 730 shown in Figure 13B, a guide groove 734 is formed below the positioning portion 732. The guide groove 734 is for filling with conductive adhesive to form a conductive structure 760. As shown in Figure 14A, the optical element 750 is positioned on the positioning portion 732 of the bracket 730, shielding the conductive structure 760 located below in the guide groove 734. A sealing layer 736 surrounds the optical element 750 to prevent moisture and protect it.

In this invention, the size and shape of the positioning part 732 can be adjusted according to the actual application, as illustrated in the top view of other bracket designs shown in Figures 14B to 14D. For example, the width W of the positioning portion 732 is formed such that when the two sides of the optical element 750 are placed in the positioning portion 732, they can directly abut against two opposite sides of the bracket 730 (as shown in Figure 14B). The conductive adhesive is filled into the guide groove (not shown) below the optical element 750. The portion of the optical element 750 that does not abut against the side wall of the bracket and the positioning portion 732 is filled with light-transmitting adhesive to form a sealing layer 736. Alternatively, as shown in Figure 14C, the width W of the positioning portion 732 can be formed to be narrower than the optical element 750 and longer than the optical element 750 so as not to be blocked by the optical element 750, thereby forming a filling space C for filling with conductive adhesive to form a conductive structure 760. The remaining structural design of the bracket 730 is similar to that of the aforementioned embodiment and will not be described in detail here.

Furthermore, to further facilitate the adhesive application process and to create different conductive structures on the bracket, various guide groove structures can be designed for the bracket. Figure 14D shows a top view of a bracket 730 without the optical element 750. In addition to the aforementioned positioning part 732 and guide groove 734 for filling with conductive adhesive, secondary guide grooves 738, slightly shallower than the guide grooves 734, can also be formed on opposite sides of the bracket 730. The secondary guide grooves 738 connect the guide grooves 734 and the sidewall 730A, and their structure facilitates the filling of conductive adhesive into the depth of the guide grooves 734.

In this invention, besides using plastic injection molding, casting, 3D printing, or other methods to form a plastic support covering the electrical conductive structure for electrical conduction, a metal support can also be used to directly provide electrical connection. However, it is important to note that the metal support must have a disconnected interface to distinguish the positive and negative electrodes. The metal support itself possesses a conductive metal structure that can be directly connected to the conductive layer or metal plating layer on the underlying substrate to form a conductive connection.

Based on the foregoing, this invention provides a laser package structure with a protection mechanism and a wafer-level packaging process for fabricating this laser package structure. With this invention, instead of using separate photodiodes and external circuits as protection mechanisms as in conventional laser package structures, an electrically conductive structure is formed and coated on the support of the optical components. This electrically conductive structure is used to connect the electrically conductive optical components, thereby significantly reducing the overall size of the package structure or module and reducing the risk of module failure due to external circuit breakage. Furthermore, the wafer-level packaging process design also reduces manufacturing processes and costs.

In addition to the aforementioned features, this invention further improves the quality and efficiency of adhesive application through the design of various guide groove structures on the support. Specifically, in this invention, conductive or non-conductive adhesives can be used to fill the space around the optical components and between the support in the encapsulation structure, ensuring a sealed internal cavity and preventing moisture intrusion that could affect the function of the optical components.

In the laser packaging structure of this invention, the air layer required to separate the laser chip and optical components can be formed by the placement of spacers of a predetermined height or directly by filling with packaging adhesive of a predetermined thickness, increasing the flexibility of the packaging structure design. Furthermore, the use of a stencil to apply conductive adhesive allows the conductive adhesive (e.g., solder paste) overflowing from a predetermined space due to pressure during application to serve as the conductor connection for the electrodes in subsequent surface mount technology (SMT) processes, reducing process complexity.

It should be noted that the aforementioned embodiments of this invention are merely illustrative and not intended to limit the scope of the invention. Various modifications and variations made to this invention by those skilled in the art to which it pertains do not depart from the spirit and scope of this invention. Identical or similar components in different embodiments, or components represented by the same element symbols in different embodiments, possess the same physical or chemical properties. Furthermore, where appropriate, the aforementioned embodiments of this invention can be combined or substituted with each other, and are not limited to the specific embodiments described above. The connection relationships between a specific component described in one embodiment and other components can also be applied to other embodiments, all of which fall within the scope of the appended patent claims.

70: Package structure; 700: Substrate; 700A: Surface; 702A, 702B: First electrical conductive pillars; 704A, 704B: Second electrical conductive pillars; 710: Laser chip; 730: Support; 740: Cavity; 742: Electrically conductive structure; 750: Optical element; 760: Conductive structure.

Claims (19)

A packaging structure includes: a semiconductor chip including a first surface, a second surface opposite to the first surface, a side surface located between the first surface and the second surface, a first conductive structure and a second conductive structure, wherein the first conductive structure and the second conductive structure are located on the first surface of the semiconductor chip; a packaging layer disposed on the second surface of the semiconductor chip and in contact with the semiconductor chip; a support disposed at the periphery of the packaging layer; and an optical element disposed on the support. The packaging structure as described in claim 1, wherein the optical element includes a microlens array or a diffractive optical element. The packaging structure as described in claim 1, wherein the optical element includes a diffraction pattern structure. The packaging structure as described in claim 1, wherein the optical element includes a glass layer, a patterned packaging layer disposed on the glass layer and covering a portion of the conductive layer, and a conductive portion disposed at opposite ends of the peripheral region of the glass layer and covering the conductive layer. The packaging structure as described in claim 1, wherein the support and the packaging layer are made of the same material. The packaging structure as described in claim 1 further includes a patterned layer disposed on the packaging layer and located above the second surface of the semiconductor chip. The packaging structure as described in claim 6, wherein the patterned layer includes a microlens array or a diffractive optical element. The packaging structure as described in claim 6, wherein the patterned layer includes a diffraction pattern structure. As described in claim 1, a substrate includes a first electrically conductive post and a second electrically conductive post, the first electrically conductive post being electrically connected to the semiconductor chip, and the second electrically conductive post being electrically connected to a conductive component. A packaging structure includes: a semiconductor chip including a first surface, a second surface opposite to the first surface, a side surface located between the first surface and the second surface, a first conductive structure and a second conductive structure, wherein the first conductive structure and the second conductive structure are located on the first surface of the semiconductor chip; an adhesive layer directly surrounding the side surface of the semiconductor chip; and an optical element disposed on the adhesive layer. The packaging structure described in claim 10 further includes a packaging layer disposed on the semiconductor chip. The packaging structure as described in claim 10 further includes a support disposed on the adhesive layer and surrounding the semiconductor chip along the boundary of the adhesive layer, wherein the height of the adhesive layer is equal to the height of the semiconductor chip. The packaging structure described in claim 12 further includes a packaging layer disposed on the semiconductor chip and filling the space defined by the support. The packaging structure as described in claim 10, wherein the optical element includes a microlens array or a diffractive optical element. The packaging structure described in claim 10 further includes a patterned layer disposed on the second surface of the semiconductor chip. The packaging structure as described in claim 10, wherein the optical element includes a diffraction pattern structure. The packaging structure as described in claim 10, wherein the optical element includes a glass layer, a patterned packaging layer disposed on the glass layer, a patterned packaging layer disposed on the glass layer and covering a portion of the conductive layer, and a conductive portion disposed at opposite ends of the peripheral region of the glass layer and covering the conductive layer. The packaging structure as described in claim 12, wherein the adhesive layer includes at least one conductive adhesive penetrating the adhesive layer, the support includes a conductive component penetrating the support and electrically connected to the conductive adhesive; and the optical element is electrically connected to a substrate via the conductive component and a conductive layer. The packaging structure as described in claim 18, wherein the at least one conductive adhesive fills the adhesive layer and is disposed between the adhesive layer and the support.