TWI682604B - Package structure for edge-emitting laser - Google Patents

Abstract

A package structure for an edge-emitting laser includes a carrier, a housing, an edge-emitting laser, a first reflective member, a second reflective member, and a diffractive optical element. The carrier has a mounting surface. The housing is disposed on the mounting surface, and the housing has a receiving space therein. The top surface of the housing has an opening and a central line vertical to the top surface and the mounting surface. The edge-emitting laser is disposed in the receiving space and is disposed on the mounting surface, and the edge-emitting laser has a light-emitting surface for emitting a laser beam. The first reflective member is disposed in the receiving space and spaced apart from the light emitting surface of the edge-emitting laser. The second reflective member is disposed in the receiving space and is located on the central line above the edge-emitting laser. The diffractive optical element is disposed on the top surface of the housing. The laser beam is reflected by the first reflective element and the second reflective element, and passes through the diffractive optical element to emit outside the housing.

Description

Packaging structure of edge-firing laser

The present invention relates to a packaging structure, and in particular to an edge-emitting laser packaging structure.

The traditional laser light emitting element is mounted on the substrate in a lead-type packaging structure, and the vertical distance between the mounting surface and the collimating lens is too large (greater than 9mm), so that the overall height of the packaging structure is increased, and the volume is relatively increased, resulting in occupation Shortcomings such as too much space.

Therefore, how to reduce the overall height of the packaging structure is an issue that the industry urgently wants to overcome.

The invention relates to a package structure of an edge-beam laser. Using two reflective elements to change the transmission path of the edge-beam laser can reduce the overall height of the package structure and keep the optical axis at the center of the package structure. Suitable for portable electronic devices.

According to one aspect of the present invention, an edge-type laser package structure is provided, which includes a carrier board, a housing, an edge-type laser, a first reflective element, a second reflective element, and a diffractive optical lens . The carrier board has a bearing surface. The casing is arranged on the bearing surface, the casing has an accommodating groove, the top surface of the casing has an opening, and a vertical top surface and a center line of the bearing surface. The side-firing laser is disposed in the accommodating groove and located on the bearing surface. The side-firing laser has a light-emitting surface for emitting a laser light. The first reflective element is disposed in the accommodating groove, and is spaced apart from the light exit surface. The second reflective element is disposed in the accommodating groove and located on the center line above the edge-fired laser. The diffractive optical lens is disposed on the top surface of the housing, wherein the laser light is reflected by the first reflective element and the second reflective element, and passes through the diffractive optical lens to exit the housing.

In order to have a better understanding of the above and other aspects of the present invention, the following examples are specifically described in conjunction with the accompanying drawings as follows:

The following is an example for detailed description. The example is only used as an example, not intended to limit the scope of the present invention. The following description uses the same/similar symbols to indicate the same/similar components. Directional terms mentioned in the following embodiments, for example: up, down, left, right, front or back, etc., are only directions referring to the drawings. Therefore, the directional terminology is used to illustrate rather than limit the invention.

According to an embodiment of the invention, an edge emitting laser (EEL) packaging structure is proposed. An edge-emitting laser is a semiconductor device, such as a gallium arsenide chip, which generates resonance resonance by photon reflection back and forth in the resonant cavity, and then enables a coherence (coherence) high-energy beam from the side of the chip The light exit surface is emitted to produce laser light, so it is called "edge-shot laser". The laser power is high, and the projected light field can be elliptical. Compared with the surface emitting laser (SEL), the laser light is emitted from the surface of the wafer, so it is called "surface emitting laser". This kind of laser has low power and the projected light field can be It is a perfect circle.

In application, the package structure of the edge-beam laser or the surface-beam laser can be used as a dot projector to project the structured light on the target object for the image sensor to carry out three-dimensional stereoscopic images Depth recognition or face recognition, etc.

Referring to FIGS. 1 and 2, the package structure 100 for an edge-firing laser according to an embodiment of the present invention includes a carrier 110, a housing 120, a side-firing laser 130, a first reflective element 140, and A second reflective element 150. The carrier 110 has a bearing surface 112. The casing 120 is disposed on the bearing surface 112, and the bottom surface 121 of the casing 120 is fixed on the bearing surface 112 with adhesive, for example, so that the interior of the casing 120 forms a sealed space.

In one embodiment, the cross-section of the housing 120 is, for example, a zigzag structure, and an accommodating groove 124 is provided inside. The top surface 122 of the housing 120 has an opening 123 that communicates with the receiving groove 124. The top surface 122 of the housing 120 is preferably parallel to the bearing surface 112 and separated by a predetermined distance. The opening 123 is located on the side of the housing 120 away from the carrier board 110, and the center of the opening 123 is substantially on the center line C. The center line C is substantially located in the center of the housing 120, and the center line C is perpendicular to the top surface 122 and the bearing surface 112 of the housing 120.

Please refer to FIG. 2. In an embodiment, the edge-type laser package structure 100 may further include a collimating lens 160, a fixing member 162 and a diffractive optical lens 164. The collimating lens 160 is disposed in the opening 123, and the center of the collimating lens 160 is substantially on the center line C. The collimating lens 160 can make the laser light L form a beam parallel to the center line C, that is, the laser light parallel to the optical axis, so as to reduce the energy loss of light propagation. The diffractive optical lens 164 may be disposed in the fixing member 162 and disposed on the top surface 122 of the housing 120 via the fixing member 162. However, the diffractive optical lens 164 can also be disposed on the top surface 122 of the housing 120 by other means, and does not limit the embodiment shown in the drawings. The diffractive optical lens 164 is used to shape the light beam passing through the collimating lens 160 and output it outward. Through the design of the pattern of the diffractive optical lens 164, the package structure can generate specific structure light.

The edge-firing laser 130 is disposed in the accommodating groove 124 and is located on the supporting surface 112 of the carrier 110. The side-firing laser 130 has a light emitting surface 132 for emitting a laser light L. The edge-emitting laser 130 is fixed on the supporting surface 112 by, for example, surface-mounting adhesive, and the carrier board 110 is, for example, a circuit board, which is electrically connected to the edge-emitting laser 130 by wires. However, the edge-firing laser 130 may also be disposed on the carrying surface 112 by other methods, and the embodiment shown in the drawings is not limited.

The first reflective element 140 is disposed in the accommodating groove 124 and located on the bearing surface 112 of the carrier board 110. That is to say, the first reflective element 140 and the edge-emitting laser 130 are coplanarly disposed, and are separated by a predetermined distance. In one embodiment, the first reflective element 140 can be fixed on the supporting surface 112 by means of adhesive or plug-in connection, and the first reflective element 140 has a first reflective surface 142, for example, a reflective surface Mirror or a reflective coating. The first reflective element 140 is preferably a mirror or a diamond mirror with a reflectivity greater than 80% to reduce light loss.

The second reflective element 150 is disposed in the accommodating groove 124 and is located on the center line C above the edge-emitting laser 130. That is to say, the first reflective element 140 and the edge-emitting laser 130 are not coplanar, and the first reflective element 140 and the second reflective element 150 are separated by a predetermined distance. The first reflective element 140 and the second reflective element 150 have A height difference.

The first reflective element 140 and the second reflective element 150 are, for example, tapered or right-angled triangles, and their sizes can be adjusted according to actual needs. In an embodiment, the height and slope length of the second reflective element 150 are, for example, at least 3 times the height and slope length of the first reflective element 140, so that the second reflective element 150 has a sufficiently large reflective area to reflect the laser light L Guide to the center of the housing 120.

Please refer to FIG. 2, in an embodiment, a fixing frame 114 is disposed in the accommodating groove 124, and the second reflective element 150 may be disposed on the fixing frame 114 so that the second reflective element 150 is located in the side-firing laser 130 Above. The fixing frame 114 is fixed on the bearing surface 112 by, for example, adhesive or plugging. The second reflective element 150 can be fixed on the fixing frame 114 by means of glue or plugging, so that the bottom surface of the second reflective element 150 has a height difference with respect to the bearing surface 112. In an embodiment, the fixing frame 114 is, for example, T-shaped. The fixing frame 114 includes a horizontal surface 114a and a vertical surface 114b. The second reflective element 150 is disposed above the horizontal surface 114a. The horizontal surface 114a is parallel to the bearing surface 112 and has a height difference The vertical surface 114b is connected between the horizontal surface 114a and the bearing surface 112, and the above-mentioned height difference is substantially equivalent to the height of the edge-firing laser 130 to reduce the overall height of the packaging structure 100. In addition, the second reflective element 150 has a second reflective surface 152, for example, a reflective mirror surface or a reflective coating. The second reflective element 150 is preferably a mirror or a mirror with a reflectivity greater than 80% to reduce light loss.

Please refer to FIG. 3, which shows the optical path diagram of the laser light L. The edge-emitting laser 130 has a light-emitting surface 132 facing the first reflective element 140. After the laser light L is emitted from the light exit surface 132, it is reflected by the first reflection surface 142 and reaches the second reflection surface 152. The first reflecting surface 142 has a first included angle θ with respect to the optical axis C, the second reflecting surface 152 has a second included angle α with respect to the optical axis C, and the total of the first included angle θ and the second included angle α is 45 degrees.

Please refer to FIG. 3, the laser light L reaches the first reflecting surface 142 at a first incident angle θ, and then reflects at a first reflecting angle θ. Next, when the laser light L reaches the second reflective surface 152 at a second incident angle, the angle between the laser light L and the horizontal line H and the sum of the first incident angle and the first reflected angle are internally offset angles, so it can be known The angle of the laser light L relative to the horizontal line H may be twice the first angle θ, that is, equal to 2θ. The included angle between the laser light L and the second reflective surface 152 is defined as the second included angle α, where the second incident angle may be defined as the complementary angle of the second included angle α.

Then, after the laser light L is reflected at a second reflection angle, the laser light L is emitted along the center line C substantially in the vertical axis. It can be seen from the figure that the included angle between the second reflecting surface 152 and the horizontal line H is the sum of twice the first reflected angle and the second included angle α, that is, equal to 2θ+α, and the vertex angle is also 2θ+α. In addition, since the sum of the angle (2θ+α) between the second reflective surface 152 and the horizontal line H and the second angle α is equal to 90 degrees, that is, 2(θ+α)=90 degrees, it can be known that the first angle θ and the second The sum of the two angles α is 45 degrees.

According to the above formula, when the sum of the first included angle θ and the second included angle α is 45 degrees, the sum of the included angle between the first reflective surface 142 and the optical axis C and the included angle between the second reflective surface 152 and the optical axis C is At 45 degrees, the optical path of the laser light L can be emitted along the optical axis C, and the optical path of the laser light L is substantially maintained at the center of the packaging structure 100 without being shifted above the first reflective element 140. Therefore, the deviation of the optical path of the laser light L can be avoided, thereby reducing the adjustment time.

In addition, after the laser light L of the edge-emitting laser 130 undergoes secondary reflection, the optical path distance increases. Therefore, the vertical distance between the top surface 122 of the housing 120 and the bearing surface 112 of the carrier board 110 can be greatly reduced, for example, less than 5 mm In order to reduce the overall height of the packaging structure 100, and the volume of the packaging structure 100 is also relatively reduced to meet market demand.

Next, please refer to FIG. 4, which illustrates a schematic diagram of an edge-type laser package structure 100 having a plurality of collimating lenses 160. The arrangement is substantially the same as the above-mentioned embodiment, except for: a plurality of collimating The lens 160 is disposed in the opening 123, and the shape and height of the second reflective element 150 can be changed, which conforms to the overall height of the packaging structure 100. In this embodiment, although the height of the second reflective element 150 is reduced, the laser light L can still be reflected by the first reflective element 140 and the second reflective element 150, and then pass through the collimating lens 160 and the diffractive optical lens 164. And out of the housing 120 along the optical axis C. In this embodiment, a plurality of collimating lenses 160 are used, and a better light type can be obtained than using one collimating lens 160.

Next, please refer to FIG. 5, which illustrates a schematic diagram of a package structure 100 of an edge-beam laser with a diffractive optical lens 164 and a collimator lens 160 combined together. The point is that the diffractive optical lens 164 and the collimating lens 160 are combined into a single element 165. In this way, the diffractive optical lens 164 and the collimating lens 160 can be directly arranged in the opening 123 of the housing 120, and there is no need to install it for fixing The fixing member 162 of the diffractive optical lens 164 reduces the number of components, and can further reduce the overall height of the packaging structure 100.

Next, please refer to FIG. 6, which shows a schematic diagram of a package structure 100 of a side-firing laser in which the fixing frame 114 is integrally formed inside the housing 120. The configuration is substantially the same as the above embodiment, except for: fixing The frame 114 and the housing 120 are combined into a single component, for example, integrally formed by injection molding, so that the number of components and the time for component installation can be reduced. In addition, in the above embodiment, the aperture of the opening 123 is smaller than the width of the accommodating groove 124, and in this embodiment, the housing 120 is, for example, a hollow cylinder, and the aperture of the opening 123 is, for example, the size of the accommodating groove 124 Equal to further reduce the volume of the packaging structure 100.

The package structure of the edge-type laser disclosed in the above embodiments of the present invention can overcome the problem that the vertical distance between the mounting surface of the conventional edge-type laser and the collimator lens is too large, so as to reduce the overall height of the package structure. In addition, after the secondary reflection, the laser light can maintain the optical path of the laser light roughly in the center of the package structure, thus avoiding the need to adjust the optical path offset error of the traditional laser light path. In turn, the adjustment time is reduced.

In summary, although the present invention has been disclosed as above with examples, it is not intended to limit the present invention. Those with ordinary knowledge in the technical field to which the present invention belongs can make various modifications and retouching without departing from the spirit and scope of the present invention. Therefore, the scope of protection of the present invention shall be deemed as defined by the scope of the attached patent application.

100‧‧‧Package structure of side-firing laser 110‧‧‧ carrier board 112‧‧‧ Bearing surface 114‧‧‧Fixing frame 114a‧‧‧horizontal 114b‧‧‧Vertical 120‧‧‧Housing 121‧‧‧Bottom 122‧‧‧Top 123‧‧‧ opening 124‧‧‧Accommodation slot 130‧‧‧Laser fire 132‧‧‧Glossy 140‧‧‧First reflection element 142‧‧‧First reflection surface 150‧‧‧Second reflection element 152‧‧‧Second reflection surface 160‧‧‧collimating lens 162‧‧‧Fixed parts 164‧‧‧diffractive optical lens 165‧‧‧Single component C‧‧‧Light axis L‧‧‧Laser θ‧‧‧ First angle α‧‧‧Second included angle H‧‧‧horizontal line

FIG. 1 is a schematic diagram of a package structure of an edge-firing laser according to an embodiment of the invention. FIG. 2 shows an internal schematic diagram of an edge-beam laser package structure with dual reflective elements. Figure 3 shows the optical path diagram of laser light. FIG. 4 shows an internal schematic diagram of an edge-type laser package structure with multiple collimating lenses. FIG. 5 shows an internal schematic diagram of an edge-type laser package structure with integrally formed diffractive optical lens and collimating lens. FIG. 6 is an internal schematic view of a package structure of an edge-beam laser in which the fixing frame is integrally formed inside the casing.

100‧‧‧Package structure of side-firing laser

110‧‧‧ carrier board

112‧‧‧ Bearing surface

114‧‧‧Fixing frame

114a‧‧‧horizontal

114b‧‧‧Vertical

120‧‧‧Housing

121‧‧‧Bottom

122‧‧‧Top

123‧‧‧ opening

124‧‧‧Accommodation slot

130‧‧‧Laser fire

132‧‧‧Glossy

140‧‧‧First reflection element

142‧‧‧First reflection surface

150‧‧‧Second reflection element

152‧‧‧Second reflection surface

160‧‧‧collimating lens

162‧‧‧Fixed parts

164‧‧‧diffractive optical lens

C‧‧‧Centerline (optical axis)

L‧‧‧Laser

Claims (10)

An edge-shot laser packaging structure includes: a carrier board with a bearing surface; a housing disposed on the bearing surface, the housing has an accommodating groove inside, and the top surface of the housing has a An opening and a center line perpendicular to the top surface and the bearing surface; a side-firing laser, which is disposed in the accommodating groove and located on the carrying surface, the side-firing laser has a light-emitting surface for emission A laser light; a first reflective element, disposed in the accommodating groove, spaced apart from the light exit surface; a second reflective element, disposed in the accommodating groove, and located above the edge-fired laser Center line; and a diffractive optical lens, disposed on the top surface of the housing, wherein the laser light is reflected by the first reflective element and the second reflective element, and passes through the diffractive optical lens to exit the shell Outside the body. The packaging structure as described in item 1 of the patent application scope further includes a collimating lens disposed in the opening, the laser light is reflected by the first reflecting element and the second reflecting element in sequence The collimator lens and the diffractive optical lens are used to exit the housing. The packaging structure as described in item 2 of the patent application scope, wherein the collimating lens and the diffractive optical lens are integrally formed. The packaging structure described in item 1 of the patent application scope further includes a fixing member, the diffractive optical lens is disposed on the fixing member, and the fixing member is disposed on the top surface of the housing. The packaging structure as described in item 1 of the scope of the patent application further includes a fixing frame, the fixing frame is disposed on the bearing surface and accommodated in the accommodating groove, and the second reflective element is disposed on the fixing frame. According to the packaging structure described in item 5 of the patent application scope, the other fixing frame is T-shaped, the fixing frame includes a horizontal plane and a vertical plane, the second reflective element is disposed above the horizontal plane, the horizontal plane is parallel to the bearing surface It also has a height difference, the vertical plane is connected between the horizontal plane and the bearing surface, and the height difference is equivalent to the height of the edge-fired laser. The packaging structure as described in item 1 of the patent application scope further includes a fixing frame integrally formed inside the housing and accommodated in the accommodating groove, and the second reflective element is disposed on the fixing frame on. The packaging structure as described in item 1 of the patent application scope, wherein the first reflective element has a first reflective surface, the second reflective element has a second reflective surface, and the angle between the first reflective surface and the centerline and The sum of the angle between the second reflecting surface and the center line is 45 degrees. The packaging structure as described in item 8 of the patent application scope, wherein the first reflective surface or the second reflective surface is a reflective mirror or a reflective coating. The packaging structure as described in item 1 of the patent application scope, wherein the first reflective element and the edge-emitting laser are coplanar, and the first reflective element and the second reflective element have a height difference.

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