Packaging structure

Abstract

A package structure includes a substrate; at least one optoelectronic element disposed on the substrate, the at least one optoelectronic element having an emission surface; a front lens disposed on the substrate, the front lens having a front emission surface and a back surface opposite the front emission surface, wherein the emission surface of the at least one optoelectronic element faces the front lens; and a package disposed on the substrate and covering the at least one optoelectronic element and the front lens, a front end surface of the package forming a step structure with the front emission surface of the front lens.

Description

Technical Field

[0001] This utility model relates to a packaging structure, and more particularly to a laser diode packaging structure used in optical radar. Background Technology

[0002] In existing technologies, LiDAR (Light Detection and Ranging) has been widely used in various fields, such as autonomous vehicles, automated guided vehicles (AGVs) for industrial automation, distance measurement, and stereo imaging sensing. However, the laser diode packaging structure used to construct LiDAR still has several drawbacks. For example, due to the draft angle of the silicone mold, it is difficult to achieve a straight side emitting surface. Limited by the aforementioned technologies, it is difficult to incorporate multiple chips in LiDAR. Furthermore, the packaging structure is prone to generating sawdust during the cutting process, which can contaminate the side emitting surface, indicating that there is still room for improvement in the structural design of the laser diode packaging structure. Utility Model Content

[0003] The technical problem to be solved by this utility model is to provide a packaging structure that addresses the shortcomings of the prior art and solves the above-mentioned defects.

[0004] To solve the above-mentioned technical problems, one of the technical solutions adopted by this utility model is to provide a packaging structure, which includes a substrate; at least one optoelectronic element disposed on the substrate, the at least one optoelectronic element having a light-emitting surface; a front lens disposed on the substrate, the front lens having a front light-emitting surface and a back surface opposite to the front light-emitting surface, wherein the light-emitting surface of the at least one optoelectronic element faces the front lens; and a package body disposed on the substrate and covering the at least one optoelectronic element and the front lens, wherein a front end face of the package body and the front light-emitting surface of the front lens form a discontinuity structure.

[0005] According to a feasible embodiment of this application, the height of the front lens is greater than the height of the at least one optoelectronic element, the height of the package is greater than the height of the front lens, and the distance between the front end surface of the package and the front light-emitting surface of the front lens is between 100 μm and 150 μm.

[0006] According to a feasible embodiment of this application, the substrate includes at least one carrier lead frame, a plurality of wiring lead frames and a molding material, the molding material being filled between and around the at least one carrier lead frame and the plurality of wiring lead frames, the at least one optoelectronic element being disposed on the at least one carrier lead frame, and the front end edge of the at least one carrier lead frame being aligned with the front light-emitting surface of the front lens.

[0007] According to a feasible embodiment of this application, each of the at least one lead frame has an arm extending outward from both sides, and each arm forms a positioning hole.

[0008] According to a feasible embodiment of this application, the front lens has a pair of side extensions, which are respectively located on both sides of the at least one photoelectric element. The outer surfaces of the pair of side extensions are aligned with the outer surfaces of the arm portion. Each side extension forms a positioning post, which is disposed in the positioning hole.

[0009] According to a feasible embodiment of this application, the front lens further includes a plurality of inner partitions located between the pair of side extensions, thereby forming a plurality of receiving recesses, each of the receiving recesses being provided with one of the photoelectric elements.

[0010] According to a feasible embodiment of this application, the front lens further includes two oblique light-emitting surfaces located on both sides of the front light-emitting surface, each of the oblique light-emitting surfaces forming an acute angle with the front light-emitting surface.

[0011] According to a feasible embodiment of this application, the front light-emitting surface of the front lens has at least one convex lens, the position of which corresponds to the at least one photoelectric element.

[0012] According to a feasible embodiment of this application, a light-transmitting adhesive is also included, wherein there is a gap between the back surface of the front lens and the light-emitting surface of the at least one photoelectric element, the light-transmitting adhesive covers a portion of the at least one photoelectric element and fills the gap, and abuts against a portion of the back surface of the front lens.

[0013] According to a feasible embodiment of this application, the length of the gap along the light emission direction of the at least one optoelectronic element is between 30 μm and 70 μm.

[0014] According to a feasible embodiment of this application, the encapsulation body is made of an opaque material.

[0015] One of the advantages of this invention lies in the use of a pre-formed front lens. The front lens has a straight-walled or focusing lens structure, suitable for side emission of edge-emitting laser (EEL) chips, enabling a vertical side-emitting surface. Furthermore, the substrate of this invention employs a pre-formed lead frame design. Moreover, the pre-formed lead frame design enhances the strength of the substrate, and the opaque encapsulant reduces internal stress throughout the package, thereby improving product reliability.

[0016] To further understand the features and technical content of this utility model, please refer to the following detailed description and drawings of this utility model. However, the drawings provided are for reference and illustration only and are not intended to limit this utility model. Attached Figure Description

[0017] Figure 1 This is an exploded perspective view of the first embodiment of the packaging structure of this utility model.

[0018] Figure 2 This is a partial assembly diagram of the packaging structure of this utility model.

[0019] Figure 3 This is a schematic diagram of the packaging structure of this utility model.

[0020] Figure 4 This is a schematic diagram of another combination of the packaging structure of this utility model.

[0021] Figure 5 This is a top view of the packaging structure of this utility model.

[0022] Figure 6 This is a side view of the packaging structure of this utility model.

[0023] Figure 7 This is a top view of the second embodiment of the packaging structure of this utility model.

[0024] Figure 8 This is a top view of the third embodiment of the packaging structure of this utility model. Detailed Implementation

[0025] The following specific embodiments illustrate the implementation methods disclosed in this utility model. Those skilled in the art can understand the advantages and effects of this utility model from the content disclosed in this specification. This utility model can be implemented or applied through other different specific embodiments, and various details in this specification can also be modified and changed based on different viewpoints and applications without departing from the concept of this utility model. Furthermore, the accompanying drawings of this utility model are for simple illustrative purposes only and are not depictions of actual dimensions, as stated in advance. The following embodiments will further describe the relevant technical content of this utility model in detail, but the disclosed content is not intended to limit the scope of protection of this utility model. Additionally, the term "or" as used herein may include, depending on the actual situation, any combination of any one or more of the associated listed items.

[0026] [First Embodiment]

[0027] like Figures 1 to 7As shown, this utility model provides a packaging structure 100, which includes a substrate 10, at least one optoelectronic element 20 disposed on the substrate 10, a front lens 30 disposed on the substrate 10, and a package 40 disposed on the substrate 10. The packaging structure 100 of this utility model can be used, for example, as an optical radar transmitter.

[0028] The substrate 10 includes at least one lead frame 121, multiple lead frames 122, and a molding material 14. In this embodiment, a slightly T-shaped lead frame 121 and two lead frames 122 are located on either side of the lead frame 121, together forming a unit of a lead frame 12. The lead frame 121 and the lead frames 122 are made of conductive material and partially extend downwards and are exposed at the bottom of the substrate 10 (e.g., ...). Figure 4 (As shown), it serves as an electrode. Two lead frames 122 are generally inverted L-shaped, mirror-symmetrically positioned on either side of the carrier lead frame 121, with the two L-shaped bends adjacent to the connection points of the T-shaped carrier lead frames 121, i.e., the inner angles. Furthermore, the carrier lead frame 121 and the multiple lead frames 122 each have a half-etched structure at their bottoms. Further, on the front and back sides of the substrate 10, except for the bottom surfaces of the carrier lead frame 121 and the two lead frames 122 which are exposed above the outer surface of the encapsulation structure, the remaining portions of the carrier lead frame 121 and the multiple lead frames 122 are covered by the molding material 14. That is, the molding material 14 fills the space between and around the carrier lead frame 121 and the multiple lead frames 122, forming a flat substrate 10. The optoelectronic element 20 is disposed on the top surface of the carrier lead frame 121.

[0029] The optoelectronic element 20, for example, can be an edge-emitting laser (EEL). The optoelectronic element 20 has a vertical light-emitting surface 201 located on the side, from which light is emitted to form an elliptical beam with a wavelength, for example, between 850 nm and 1200 nm.

[0030] The optoelectronic element 20 is coupled to the lead frame 12 of the substrate 10 via wiring 202. However, this invention does not preclude the optoelectronic element 20 from being coupled to the lead frame 12 of the substrate 10 via flip-chip coupling. The optoelectronic element 20 can be one or more, disposed on the top surface of the substrate 10. Embodiments with multiple optoelectronic elements will be described by example later.

[0031] The front lens 30 is pre-molded from a light-transmitting material, such as resin, polycarbonate (PC), or other light-transmitting materials. The front lens 30 has a front light-emitting surface 301, a back surface 302 opposite to the front light-emitting surface 301, and a top surface 303. In this embodiment, the front light-emitting surface 301 of the front lens 30 can present a vertical plane perpendicular to the substrate 10. The light-emitting surface 201 of the photoelectric element 20 faces the front lens 30. In this embodiment, the front light-emitting surface 301 of the front lens 30 is aligned with the front end edge of the lead frame 121 of the substrate 10. Furthermore, the front light-emitting surface 301 of the front lens 30 preferably has at least one convex lens 33, the position of which corresponds to the light-emitting surface 201 of the photoelectric element 20. The middle portion of the convex lens 33 has an arcuate cross-section.

[0032] like Figure 5 and Figure 6 As shown, in this embodiment, the back surface 302 of the front lens 30 and the light-emitting surface 201 of the photoelectric element 20 have a gap D2. For example, the length of the gap D2 along the light-emitting direction of the photoelectric element 20 is between 30 μm and 70 μm. The encapsulation structure 100 also includes a light-transmitting adhesive 50, which covers the front end of at least one photoelectric element 20 on the light-emitting side and fills the gap D2, and abuts against the back surface 302 of a portion of the front lens 30. For example, the light-transmitting adhesive 50 can be a light-transmitting silicone gel.

[0033] Please see Figure 1 In this embodiment, the positioning mechanism between the front lens 30 and the substrate 10 is described as follows. An arm 1212 extends outward from each side of the lead frame 121, and each arm 1212 forms a positioning hole 1210. In this embodiment, the positioning hole 1210 does not penetrate the lead frame 121, and the depth of the positioning hole 1210 can be less than or equal to half the thickness of the lead frame 121. The front lens 30 has a pair of side extensions 32 located on both sides of the photoelectric element 20. The outer surfaces of the side extensions 32 are aligned with the outer surfaces of the arm 1212, and each side extension 32 extends downward to form a positioning post 321. The positioning post 321 is disposed within the positioning hole 1210. Furthermore, the extension length of each side extension 32 must exceed 1 / 3 of the length of the photoelectric element 20, preferably 1 / 2. Furthermore, the side extension 32 is preferably partially extended onto the molding material 14 of the substrate 10 to improve the bonding strength. In addition, the outer side of the side extension 32 is also aligned with the outer side of the substrate 10.

[0034] The encapsulation 40 in this embodiment is composed of an opaque colloidal material, such as black or white epoxy molding compounds (EMC). The epoxy molding compound mainly consists of epoxy resin, phenol, a hardener, silica powder, and other additives. The encapsulation 40 is disposed on the substrate 10 and encapsulates the optoelectronic element 20, the transparent adhesive 50, and the front lens 30. For example, the encapsulation 40 can utilize a low-stress molding technique. Figures 3 to 6 As shown, a front end face 401 of the package 40 and the front light-emitting surface 301 of the front lens 30 form a discontinuity structure. In other words, the front end face 401 of the package 40 is slightly recessed and not flush with the front light-emitting surface 301 of the front lens 30, forming a gap D1. Specifically, the distance of the gap D1 is preferably between 100μm and 150μm. This discontinuity structure helps to avoid material overflow during the molding process of the package 40, thereby not only avoiding contamination of the front lens 30, but also eliminating the need for subsequent material removal steps. Furthermore, from another perspective, the height of the front lens 30 is greater than the height of the optoelectronic element 20, and the height of the package 40 is greater than the height of the front lens 30.

[0035] In addition, the encapsulation body 40 of this utility model can also be composed of a light-transmitting colloidal material, and the exterior of the encapsulation body 40 can be covered by a coating or other materials. This embodiment can omit the light-transmitting adhesive 50; in other words, the encapsulation body 40 can directly fill the gap D2 between the front lens 30 and the photoelectric element 20.

[0036] In this embodiment, the two sides and the rear side of the package 40 can be formed into a single package structure by cutting. In other words, the two sides of the package 40 can be cut flush with the two sides of the front lens 30 and the two sides of the substrate 10. In addition, the rear side of the package 40 can be cut flush with the rear side of the substrate 10.

[0037] The manufacturing process of this utility model is briefly described as follows: First, a substrate 10 with an integral structure is pre-formed. Specifically, a molding compound 14 is molded onto a whole lead frame 12 (including multiple support lead frames 121 and multiple wiring lead frames 122) using a plastic molding compound. The support lead frames 121 can be pre-stamped to form positioning holes 1210. After cutting, a single substrate 10 can be formed.

[0038] The optoelectronic element 20 is placed on the substrate 10, and wire bonding is used to couple the optoelectronic element 20 to the substrate 10. Then, the pre-formed front lens 30 is mounted on the substrate 10. The positioning post 321 at the bottom of the front lens 30 is inserted into the positioning hole 1210 of the substrate 10, which can initially position the front lens 30 on the substrate 10.

[0039] Selectively fill the gap D2 between the back surface 302 of the front lens 30 and the light-emitting surface 201 of the photoelectric element 20 with light-transmitting adhesive 50.

[0040] Finally, the package 40 is disposed on the substrate 10 and covers the photoelectric element 20 and part of the upper surface of the front lens 30, wherein the front end face 401 of the package 40 is not flush with the front light-emitting surface 301 of the front lens 30 and forms a gap D1.

[0041] [Second Embodiment]

[0042] like Figure 7 As shown, the difference between the packaging structure 100a in this embodiment and the previous embodiment is that it has two photoelectric elements 20a. The two photoelectric elements 20a are arranged in parallel or in an arc-shaped convergence, facing the front lens 30 together. Based on the dual light-emitting surfaces 201 of the photoelectric elements 20a, the convex lens 33 disposed on the front light-emitting surface 301 of the front lens 30 will have a larger arc-shaped cross-section. Therefore, the packaging structure 100a of this embodiment can provide stronger light emission intensity and a scanning angle that can be adjusted according to visual needs.

[0043] [Third Embodiment]

[0044] like Figure 8 As shown, the difference between the packaging structure 100b in this embodiment and the previous embodiment is that it has three photoelectric elements 20b, thereby enabling scanning a wider angle. The front lens 30b has a pair of side extensions 32 and also includes a plurality of inner partitions 36. Specifically, this embodiment has two inner partitions 36 with obtuse angles. The inner partitions 36 are located between the pair of side extensions 32, thereby forming three receiving recesses 38. In other words, a receiving recess 38 is formed between the two inner partitions 36, and a receiving recess 38 is formed between each side extension 32 and each inner partition 36. Each receiving recess 38 is provided with a photoelectric element 20b.

[0045] The substrate 10 includes at least one carrier lead frame 121b, two wiring lead frames 122b, and a molding material 14. In this embodiment, the carrier lead frame 121b extends to both sides to form a roughly m-shaped / umbrella-shaped carrier lead frame 121b. Three optoelectronic elements 20b are respectively disposed on multiple downward extension portions (die-bonding regions) of the carrier lead frame 121b. The two wiring lead frames 122b are located on both sides of the carrier lead frame 121b, generally in an h-shape, and are respectively disposed on both sides of the carrier lead frame 121b in a mirror-symmetrical manner. The two h-shaped turning points are respectively adjacent to the die-bonding regions of the m-shaped carrier lead frame 121b.

[0046] Another feature of this embodiment is that the front lens 30 also includes two oblique light-emitting surfaces 304 located on both sides of the front light-emitting surface 301, each oblique light-emitting surface 304 forming an acute angle θ with the front light-emitting surface 301. Figure 8 Correspondingly, the front end face 401 of the package 40b is slightly inclined to both sides to form two inclined end faces 404, which are parallel to the two inclined light-emitting surfaces 304 respectively.

[0047] The packaging structure of this invention employs a pre-formed front lens. The front lens has a straight wall or focusing lens structure, suitable for side emission of edge-emitting laser (EEL) chips, enabling a vertical side-emission surface. Furthermore, the substrate of this invention uses a pre-formed lead frame design combined with a low-stress epoxy molding (EMC) package, which not only enhances the strength of the substrate but also reduces the internal stress of the entire package, thereby improving product reliability.

[0048] Compared to existing technologies, which use molds to form silicone encapsulation structures with emission surfaces, existing technologies can only achieve small, localized side emission surfaces due to the softness of silicone. Furthermore, the entire side still has a sloping draft angle, making it impossible to form a vertical side emission surface.

[0049] The preformed lead frame has two special positioning holes for accurate positioning of the front lens. By mounting the front lens in the positioning holes on the substrate, correct focal length positioning can be achieved.

[0050] In addition, low-stress transparent adhesive (silicone) is selectively introduced to fill the gap between the front lens and the optoelectronic components, especially when the package is made of an opaque material, such as covering bonding wires or optoelectronic components.

[0051] The unit's packaging structure can be separated without sawing the outer surface of the front lens, thereby reducing contamination on the side surfaces of the optical radar transmitter.

[0052] The above-disclosed content is only a feasible embodiment of the present utility model and is not intended to limit the scope of protection of the claims of the present utility model. Therefore, all equivalent changes and modifications made based on the content of the present utility model specification and drawings are included within the scope of protection of the present utility model.

Claims

1. A packaging structure, characterized in that, include: One substrate; At least one optoelectronic element is disposed on the substrate, and the at least one optoelectronic element has a light-emitting surface; A front lens is disposed on the substrate, the front lens having a front light-emitting surface and a back surface opposite to the front light-emitting surface, wherein the light-emitting surface of the at least one photoelectric element faces the front lens; and A package is disposed on the substrate and covers the at least one optoelectronic element and the front lens, wherein a front end face of the package and the front light-emitting surface of the front lens form a discontinuity structure.

2. The packaging structure according to claim 1, characterized in that, The height of the front lens is greater than the height of the at least one optoelectronic element, the height of the package is greater than the height of the front lens, and the distance between the front end surface of the package and the front light-emitting surface of the front lens is between 100 μm and 150 μm.

3. The packaging structure according to claim 1, characterized in that, The front lens has a pair of side extensions, which are located on both sides of the at least one photoelectric element, and the outer surfaces of the pair of side extensions are aligned with the outer surfaces of the substrate.

4. The packaging structure according to claim 3, characterized in that, The front lens also includes a plurality of inner partitions located between the pair of side extensions, thereby forming a plurality of receiving recesses, each of the receiving recesses being provided with a photoelectric element.

5. The packaging structure according to claim 4, characterized in that, The front lens also includes two oblique light-emitting surfaces located on both sides of the front light-emitting surface, with each oblique light-emitting surface forming an acute angle with the front light-emitting surface.

6. The packaging structure according to claim 1, characterized in that, The substrate includes at least one support lead frame, multiple wiring lead frames, and a molding material. The molding material is filled between and around the at least one support lead frame and the multiple wiring lead frames. The at least one optoelectronic element is disposed on the at least one support lead frame, and the front edge of the at least one support lead frame is aligned with the front light-emitting surface of the front lens.

7. The packaging structure according to claim 6, characterized in that, The at least one lead frame extends outward from each of its two sides by an arm, each arm forming a positioning hole; and the front lens has a pair of side extensions located on both sides of the at least one photoelectric element, the outer surfaces of the side extensions being aligned with the outer surfaces of the arms, each side extension forming a positioning post disposed within the positioning hole.

8. The packaging structure according to any one of claims 1 to 7, characterized in that, The front light-emitting surface of the front lens has at least one convex lens, the position of which corresponds to the at least one photoelectric element.

9. The packaging structure according to any one of claims 1 to 7, characterized in that, It also includes a light-transmitting adhesive, wherein there is a gap between the back surface of the front lens and the light-emitting surface of the at least one photoelectric element, the light-transmitting adhesive covers a portion of the at least one photoelectric element and fills the gap, and abuts against a portion of the back surface of the front lens.

10. The packaging structure according to claim 9, characterized in that, The length of the gap along the light-emitting direction of the at least one optoelectronic element is between 30 μm and 70 μm.

11. The packaging structure according to claim 9, characterized in that, The encapsulation body is made of an opaque material.

12. The packaging structure according to any one of claims 1 to 6, characterized in that, The substrate is provided with at least one positioning hole, and the front lens has at least one positioning post, which is inserted into the at least one positioning hole.

13. The packaging structure according to claim 12, characterized in that, It also includes a light-transmitting adhesive, wherein there is a gap between the back surface of the front lens and the light-emitting surface of the at least one photoelectric element, the light-transmitting adhesive covers a portion of the at least one photoelectric element and fills the gap, and abuts against a portion of the back surface of the front lens.

14. The packaging structure according to claim 13, characterized in that, The length of the gap along the light-emitting direction of the at least one optoelectronic element is between 30 μm and 70 μm.

15. The packaging structure according to claim 13, characterized in that, The encapsulation body is made of an opaque material.

16. The packaging structure according to claim 6, characterized in that, The supporting lead frame is T-shaped, and there are two connecting lead frames, each of which is inverted L-shaped. The two connecting lead frames are arranged on both sides of the supporting lead frame in a mirror-symmetrical manner, and the L-shaped turning position of each connecting lead frame is adjacent to the connection point of the T-shaped supporting lead frame. The bottom of each connecting lead frame has a half-etched structure.

17. The packaging structure according to claim 6, characterized in that, The carrier lead frame extends to both sides in a slightly umbrella-shaped structure. There are two wiring lead frames, each in an h-shape. The two wiring lead frames are mirror-symmetrically arranged on both sides of the carrier lead frame. The turning points of the two wiring lead frames are adjacent to the die-bonding region of the carrier lead frame.

Images