TW202005215A - Laser diode surface mounting structure - Google Patents

Abstract

Disclosed is a packaging structure for a surface mounting laser diode, comprising at least one edge-emitted laser diode chip which contains two electrodes; a heat-conducting plate for carrying one of the two electrodes of the laser diode chip and including an upper conducting layer, a lower conducting layer, and a conducting through hole feeding through the upper and the lower conducting layers; two or more metal plates which are separately spaced from each other and disposed on a plane, where a first metal plate is disposed under the heat-conducting plate to contact the lower conducting layer, and a second metal plate is disposed separately and next to the first metal plate; and an insulating frame with an open which is disposed above the two or more metal plates to hold the two or more metal plates.

Description

Laser diode surface mounting structure

The invention relates to a laser diode surface mounting structure, especially a side-emitting laser diode packaging structure using surface mounting technology (SMT), which can meet the requirements of large current, high heat dissipation and no thermal stress.

FIG. 1, including FIGS. 1a and 1b, shows a package structure of a conventional edge-emitting medium- and high-power (referred to as an output optical power greater than 50mW) laser diode package, wherein FIG. 1a is a laser diode chip structure, Figure 1b shows the existing laser diode package architecture. Referring to FIG. 1a, the structure of a laser diode chip is based on a substrate (substrate, 100), and then atoms are deposited on the substrate by various deposition methods, called an epitaxial layer (101). For red and near-infrared (0.7~1.1um) laser diode wafers, most of them are gallium arsenide (GaAs) crystals, and infrared (1.1~1.9um) wafers are mostly indium phosphide (InP) crystals. It is used for mechanical support and heat dissipation, and is about 0.3mm thick. The epitaxial layer is a semiconductor compound composed of three or five elements such as arsenic, gallium, indium, phosphorus, and aluminum. It is subdivided into nearly ten layers and has a total thickness of about 1um. The laser resonant cavity (106) is a small area in the epitaxial layer (101) made by photomask etching technology, with a width of about 50um and a length of about 500um. The main output laser is emitted as an elliptical light cone (107), and the auxiliary output The laser direction (108) is opposite to the main output laser. Outside the substrate (100) and the epitaxial layer (101), metal is also plated to conduct electricity (not shown in FIG. 1(a)). The existing laser diode package architecture refers to FIG. 1b. The chip is fixed to the heat dissipation plate (submount, 103) that can quickly dissipate heat by soldering or gluing. The heat transfer plate has a metal layer (105), and a bonding wire (bonding wire) is connected above the chip , 102, metal conductor), the jumper connects to another metal layer (109), and the two metal layers are marked with + and-as pads, which can be used to weld wires (not shown) to supply power to the chip. The thermally conductive plate (103) is in close contact with the enclosure of the package (enclosure, 104, mostly a thin metal plate). Generally, the medium power is to attach the shell with glue, and the high power is to heat the two plates of the thermally conductive plate, and then welded to the shell. The casing is in close contact with a heat sink (heat sink, 110, also known as a heat sink) to dissipate heat. In the existing architecture, the current must be marked with (105) and (109) + and-to connect wires to and out of the chip separately, and the heat is produced from the laser resonator, passing through the heat conducting plate and the shell to the heat sink. At the junction of materials with different thermal expansion coefficients (for example, between the epitaxial layer 101 and the thermal conductive plate 103), heat will cause stress distortion crystal lattice, the laser generation efficiency of the originally good laser resonator (106) is greatly reduced, It is also extremely unfavorable to the laser quality and life. It is a technical difficulty that must be overcome by medium and high power lasers. To realize medium and high power side-firing laser diodes, it is necessary to provide large current and large heat dissipation energy at the same time. The following three points must be considered: 1. The heat is concentrated in the laser resonance cavity (106), and heat must be dissipated quickly. The substrate of the emitter diode is too thick and the thermal conductivity is too low, so most of the existing products are epitaxial layer (101) attached to a thermally conductive plate (103) that can quickly dissipate heat; 2. and epitaxial layer (101) The contacted thermally conductive plate (103) has a thermal expansion rate close to that of the epitaxial layer (101). Otherwise, thermal stress will be formed and the lattice of the epitaxial layer (101) will be distorted, which will increase the efficiency and efficiency of the laser resonator (106). The service life is also greatly reduced; 3. To avoid thermal stress, you can also use a very soft material between the epitaxial layer and the thermally conductive plate, such as indium or silver glue, to absorb the deformation caused by the expansion and contraction of the two, However, the life of these materials is not perfect. For example, indium is easy to oxidize and become very hard, and the conductivity of silver glue is not high. After heating, it will produce voids, which become obstacles to heat and current, neither of which can bear. Large current; 4. Some of the heat will still be conducted by the jumper (102). If the jumper is distributed asymmetrically on the wafer, thermal stress will also be formed.

Therefore, the existing laser diode chip structure obviously cannot meet the three requirements of high current, high heat dissipation, and no thermal stress at the same time, and there is much room for improvement. The explanation is as follows: US5825054A uses silicon as the heat conducting plate. Semiconductors can conduct electricity, but the conductivity is very low and cannot be compared with metals. The thermal conductivity of silicon is 149W/(m.K) (the units of thermal conductivity are hereinafter omitted, and the expansion coefficient is 2.6ppm/℃ (the units of expansion coefficients are hereinafter omitted, and omitted); and aluminum nitride ( AlN) has a thermal conductivity of 285 and a thermal expansion coefficient of 4.5, which is closer to 6.86 of gallium arsenide and 4.60 of indium phosphide, and also has better thermal conductivity. Heat conduction is conducted by long plug-in leads, and the path is too long to be applied to medium and high power (greater than 100mW).

DE102015114292A1 discloses two embodiments, one is that the laser chip is placed directly on the pins, and the other is the use of FR4 or ceramic PCB. Although copper is a good conductor of heat and electricity, its coefficient of expansion of 16.5 is very different from that of gallium arsenide crystal of 6.86, so it is impossible to apply it to high power. US9379517B2 also does not use a thermally conductive plate. Similarly, it cannot carry a laser chip with a large heat dissipation.

In US9728935, the upper and lower surfaces and sides of the aluminum nitride heat conduction plate are plated with metal to allow current to pass through the heat conduction plate. However, gold plating on the surface of the heat conductive plate has a limited thickness and a current path that is too long, which is not good for medium and high power.

US8130807 mentions the use of tungsten copper alloy (CuW) as a thermally conductive plate. Although the thermal expansion coefficient of CuW (6.5ppm/℃) is close to that of gallium arsenide (6.86ppm/℃), its thermal conductivity is very low (170W/m‧K ), less than one-tenth of aluminum nitride (2850W/m‧K), and cannot be used for high power.

US2018/0062346A1 is to connect multiple laser diodes in series by wire bonding, and its heat conducting plate is the same as the conventional aluminum nitride substrate, which is gold plated up and down, and does not conduct electricity up and down. In this structure, the bonding wires of the heat conduction plate are completely on a single side, and are not symmetrical, and thermal stress will inevitably occur.

Therefore, in the packaging structure of various existing laser diodes, many defects as described above will be caused. The present invention proposes a laser diode surface mounting structure that can solve the above problems in one fell swoop.

The main purpose of the present invention is to provide a surface mounting structure for a laser diode, which can take into account that the edge laser type laser diode heat is concentrated in the laser resonance cavity and the epitaxial layer must be quickly dissipated, and the thermal expansion of the thermally conductive plate in contact with the epitaxial layer The rate must be close to the epitaxial layer without forming thermal stress, which can withstand large currents, and the jumper must be symmetrically distributed on the chip and other important requirements. Therefore, a laser two that can meet high current, high heat dissipation and no thermal stress is proposed. The surface mounting structure of the polar body can overcome the lack of conventional technology and blind spots in one fell swoop.

The invention further proposes a surface mounting structure for medium and high-power laser diodes, which can quickly and efficiently dissipate heat, thereby maintaining the laser diode with better luminous efficiency and maintaining a longer life.

A laser diode surface mounting structure according to the present invention includes at least one-sided laser diode chip, including two electrodes having an anode and a cathode; a thermally conductive plate having an upper conductive layer and a lower conductive layer Layer and at least one conductor through-hole penetrating through the upper conductive layer and the lower conductive layer to support one of the two electrodes of the at least one-sided laser diode wafer, the at least one conductor through-hole Electrically conducting the upper conductive layer and the lower conductive layer; two or more metal plates spaced apart from each other and arranged on a plane, wherein a first metal plate is arranged below the thermally conductive plate and is in contact with the underlying conductive layer of the thermally conductive plate , A second metal plate is arranged adjacent to and separated from the first metal plate, the second metal plate is electrically connected to the other electrode of the two electrodes through at least one jumper; and an insulating frame with an opening, The two or more metal plates are arranged above the two or more metal plates for holding the two or more metal plates, wherein the opening is used for the laser light emitted by the at least one side-emitting laser diode chip to pass through.

According to the present invention, the laser diode chip is carried on the thermally conductive plate. The thickness of the body of the thermally conductive plate is about 0.3 mm, and does not need to be too thick. Its function is to conduct heat, and secondly to avoid the gap between the laser diode chip and the thermally conductive plate , Due to different thermal expansion coefficients and thermal stress. The main output laser beam is emitted forward out of the package, and there is another pair of output laser beams, the direction of which is opposite to the main output laser beam, and it is directed to a rear photosensitive diode. The intensity of the main output laser beam is about Fifty times the output laser beam. The material of the heat conducting plate is preferably high thermal conductivity and thermal expansion coefficient close to the laser diode chip substrate (gallium arsenide or indium phosphide), such as silicon carbide (thermal expansion coefficient 4.0), aluminum nitride or aluminum oxide (7.8), To reduce thermal stress. Both the upper and lower layers of the heat conducting plate are plated with thin film conductors (such as gold with a thickness of about um to avoid thermal stress), and a through hole is drilled from top to bottom. There are also conductors (such as gold) in the holes to make the upper and lower layers conductive. The thermally conductive plate can be extended to the left or right or forward and backward according to the heat dissipated by the laser diode chip it carries to achieve better heat dissipation capability. The first metal plate placed on the front end of the heat conducting plate has a thickness of about 0.2mm and does not need to be too thick. Its material is tin plated copper body, which functions as heat conduction and electrical conduction.

In the present invention, the manufacturing method of the metal plate is similar to the conventional integrated circuit lead frame, which is easy to mass-produce. The thermal expansion coefficient of copper is 16.5, which is very different from gallium arsenide or indium phosphide crystals, and is not suitable for directly bearing gallium arsenide or indium phosphide crystals. A tin plated copper plate carries an aluminum nitride thermally conductive plate. Since the thermal expansion coefficients of aluminum nitride or aluminum oxide and copper are very different, it can be expected that there will be a large thermal stress between the thermally conductive plate and the metal plate. However, this thermal stress will not distort the epitaxial layer nor reduce the laser life. , This is because aluminum nitride or aluminum oxide is extremely hard (Mohs hardness is 8 and 9 respectively), while copper is much softer (Mohs hardness is 3), so that this thermal stress will distort copper instead of aluminum nitride , The epitaxial layer will not be distorted, which can ensure the laser quality.

The current flows from the first metal plate through the heat conduction plate, the laser chip, the jumper, and the second metal plate. In the same way, other metal plates can also be extended to the left or right or backward according to the heat and current required by the electronic components they carry to achieve better heat dissipation capacity and current carrying capacity. Jumpers are divided into two groups, which are listed on the left and right sides of the laser chip to make them symmetrical to reduce thermal stress. The preferred arrangement of the jumper is a figure eight opening to avoid shielding the laser light that is emitted backward to the electronic component or the optical component. Since the intensity of the laser light will greatly increase with temperature, the present invention selectively uses a photosensitive diode placed behind the laser diode to monitor the intensity of the emitted light, and then inputs it into the inverting end of an operational amplifier Or a transistor to push the laser diode to realize a negative feedback light intensity stable circuit, all components of this circuit can be installed in this package. Both the first metal plate and the second metal plate can (but are not limited to) implement surface mount technology (SMT), soldered to the surface conductor (generally copper foil) on the printed circuit board, and the entire laser diode can be packaged Installed on the circuit board, it has good electrical and thermal conductivity characteristics. Below the surface conductor is the main body of the printed circuit board. The conventional FR4 (glass fiber reinforced resin), or aluminum, aluminum nitride, or aluminum oxide with better heat dissipation efficiency can be used as the main body. With this structure, most of the heat generated by the epitaxial layer is directly transmitted to the main body of the printed circuit board through the very thin heat conducting plate and the first metal plate that is very thin and can be greatly extended, the path is short, and the heat conduction speed is extremely fast . The path of the current is almost the same as the heat flow, and it is also very short. From the surface conductor of the printed circuit board through the thin first metal plate and the thin thermal conduction plate, it directly passes through the epitaxial layer and then reaches the second metal plate through the jumper Unlike the existing technology, there may be one more long jumper, so the parasitic inductance and capacitance of this architecture will be very low, which can be used for high-speed, high-current, and high-power operation.

In order to maintain the relative position of all metal plates fixed, it is held by an insulating frame. The insulating frame has an opening for the laser light to exit, to accommodate the laser diode and other components, and to protect the components from external forces.

In the present invention, an upper cover can be added to cover the insulating frame.

In order to increase the holding force of the insulating frame on the metal plate, one or more bumps can be selectively added on both sides of the metal plate. The convex hulls on both sides are still bilaterally symmetrical about the center line to avoid thermal stress. The existing metal plates are mostly straight. The improvement of the present invention is to bend two more places, which can increase the holding force of the insulating frame to the metal plate, so that the metal plate is less likely to rotate or be pulled away from the insulating frame.

In order to monitor the output power of the laser diode, a photosensitive diode, the third and fourth metal plates can be selectively installed behind the laser diode, and as mentioned above, it is also held by an insulating frame. In order to increase the efficiency of this laser diode, electronic components can be selectively installed and mounted on a metal board. Two examples are listed below. The first example is a smaller component, whose two pins and the laser The laser diode chip is connected to the first metal plate and the second metal plate, and is suitable for installing anti-static diodes, reverse bias protection diodes, capacitors or surge suppression capacitors, etc., to protect the laser diode Polar body. In practice, the laser diode is easily damaged by static electricity or surge. If there is a protective component next to it, the life of the laser diode can be greatly extended. The second example is a larger component, where one pin is connected to the first or second metal plate and one pole of the laser diode chip, and the other metal plate is connected to the other metal plate, this example is suitable for installation The current sensing resistor or thermistor is used to monitor the current and temperature of the laser diode chip. If the device will generate significant heat, consider moving its position away from the laser diode chip to maintain the symmetry of heat dissipation. If there are many metal plates for electronic components, metal plates can also be installed, such as MOSFETs that drive laser diodes, integrated circuits or the aforementioned negative feedback light intensity stabilization circuits, which must be very close to the laser diodes to avoid parasitics Inductance and capacitance can be installed next to the laser diode to achieve high-speed large-current pulses.

In order to increase the efficiency of this laser diode, one or more optical components can be optionally installed, placed at the outlet end, and clamped and fixed by an insulating frame. A groove is provided on the left and right sides of the opening of the insulating frame to accommodate the edge of the optical element. The beam of an edge-emitting laser diode must form an elliptical light cone and have a considerable astigmatism (astigmatisim), which is very unfavorable for precision applications. It is often necessary to use optical components to modify its beam before it is easy to apply. A cylindrical mirror or prism rounds the elliptical light cone to a round shape. Furthermore, most laser applications utilize collimated light beams. Therefore, in the present invention, a collimating lens (convex lens) can be placed at the exit end of the laser light to converge the divergent light cone into a collimated light beam. After becoming a collimated beam, a diffraction grating (or hologram) can be added to produce a specific pattern, or an optical crystal (such as Nd:YAG yttrium aluminum garnet) can be added to produce a solid-state laser, and then Adding a non-linear crystal (such as potassium titanyl phosphate KTiOPO4-KTP, or lithium metaphosphate LiB ₃ O ₅ -LBO, also known as a second harmonic generator) can generate light waves with a wavelength half that of the original laser. The optical element is clamped and fixed with an insulating frame, the optical element can be very close to the laser, and the light cone can be collected before the divergence is large, and the beam diameter can be small, so that the subsequent optical lens and the entire The system can be reduced to a very small size, which can greatly increase the application area.

In order to increase the heat dissipation effect, the first metal plate can be enlarged, but in order to prevent the expanded first metal plate from blocking outgoing light, a cutout can be selectively provided in the first metal plate, and the cutout is V-shaped. In this way, there is a very large first metal plate for heat dissipation, without blocking outgoing light. The incision can also be U-shaped or other types. For example, after adding a collimating lens to converge the light cone into a collimated beam according to the above, the incision can be U-shaped, so that there can be a first metal plate with a larger area to facilitate conduction heat.

In order to increase the light-receiving area of the photodiode, the middle section of the third metal plate can be selectively twisted so that the middle section and the photodiode carried by it no longer maintain the level, but are inclined at an angle to increase the effective light-receiving area. The middle section of the third metal plate can be bent into an L-shape on one side of the laser diode, so as to support the photosensitive diode and keep it from falling before being mounted. The lowest part of the twisted middle section is maintained above the lower layer of the original metal plate, so as not to be too low, so that the surface mounting can be carried out smoothly.

If it is necessary to use an upper cover to protect the laser chip and jumpers, the upper cover can also hold one or more optical elements, and the upper cover can also be provided with a groove at the exit end to accommodate the edge of the optical element, so as to clamp the optical element on the upper cover And the first metal plate.

The optical element can also be held in half by cutting a part of the metal plate and then folding it up.

Multiple laser diode chips can be installed in the same laser diode package, and the chips can be connected in series or in parallel.

The same laser diode package can also be connected in series and in parallel with multiple laser diode chips, or a plurality of laser diode chips are connected in series and then connected in parallel, or a plurality of laser diode chips are connected in parallel and then connected in series. Different series and parallel configurations can be adopted for different power supply voltages to obtain the best power supply efficiency.

10‧‧‧Laser diode surface mounting structure

20‧‧‧Side-fired laser diode

21‧‧‧Two electrodes

211‧‧‧Anode

212‧‧‧Cathode

30‧‧‧Heat conduction board

31‧‧‧ Upper conductive layer

32‧‧‧Lower conductive layer

33‧‧‧At least one conductor hole

40‧‧‧ More than two metal plates

40-1‧‧‧First metal plate

40-2‧‧‧Second metal plate

40-3‧‧‧third metal plate

40-4‧‧‧The fourth metal plate

50, 50-1, 50-2, 50-3 ‧‧‧ jumper

60‧‧‧Insulation frame

61‧‧‧ opening

62‧‧‧Main output laser elliptical light cone

70‧‧‧Electronic components

71‧‧‧Laser exit cutout

73-1, 73-2‧‧‧Bending of metal plate

80‧‧‧ printed circuit board

81‧‧‧Surface conductor layer of printed circuit board

82‧‧‧Body of printed circuit board

90‧‧‧Optical components

100‧‧‧ substrate

101‧‧‧Epitaxial layer

102‧‧‧Jumper

103‧‧‧Heat conduction board

104‧‧‧Housing

105, 109‧‧‧ metal layer

106‧‧‧Laser resonant cavity

107‧‧‧Elliptical light cone

108‧‧‧Secondary output laser direction

110‧‧‧Heat sink

Fig. 1, including Fig. 1(a) and Fig. 1(b), Fig. 1(a) shows the structure of the laser diode chip, and Fig. 1(b) shows the surface mounting of the existing edge-fired medium-high power laser diode structure.

Fig. 2, including Fig. 2(a), Fig. 2(b), Fig. 2(c) and Fig. 2(d), shows the surface mounting structure of the edge-emitting laser diode of the present invention, and Fig. 2(a) is Side view of the thermally conductive plate, Figure 2(b) is a top view without an insulating frame, Figure 2(c) is a top view with an insulating frame, and Figure 2(d) is a side view of a combination of a laser diode chip, a thermally conductive plate, and a printed circuit board .

FIG. 3, including FIG. 3(a) and FIG. 3(b), shows a circuit connection diagram of a plurality of laser diodes according to the surface mounting structure of the laser diode according to the present invention, and FIG. 3(a) shows three lasers The parallel diagram of the laser diode wafer. Figure 3(b) is a series diagram of three laser diode wafers.

FIG. 4, including FIG. 4(a) and FIG. 4(b), FIG. 4(a) shows a top view of the third metal plate of the present invention carrying an additional electronic component, and FIG. 4(b) shows the invention carrying an additional electronic component The third metal plate of the electronic component is a side view with an oblique configuration.

FIG. 5 shows that the present invention holds the optical element with a bent metal plate.

FIG. 2, including FIG. 2(a), FIG. 2(b), FIG. 2(c) and FIG. 2(d), shows a surface mounting structure diagram of an edge-emitting laser diode according to the present invention, in which FIG. 2 (a) is a side view of a thermally conductive plate; Figure 2(b) is a top view of a laser diode chip mounted on a metal plate without an insulating frame; Figure 2(c) is the structure shown in Figure 2(b) with insulation The overall structural diagram of the frame; and FIG. 2(d) is a combined side view of the laser diode chip sequentially mounted on the thermally conductive plate, the first metal plate and the printed circuit board. Please also refer to FIG. 2(a), FIG. 2(b), FIG. 2(c) and FIG. 2(d), a laser diode surface mounting structure 10 according to the present invention includes: at least one side-fired laser diode The polar body chip 20 includes two electrodes 21 having an anode 211 and a cathode 212; a thermally conductive plate 30 having an upper conductive layer 31, a lower conductive layer 32, and at least one penetrating the upper conductive layer and the lower conductive layer Conductor through-hole 33 (detailed in FIG. 2(a)) for supporting one of poles 211 or 212 of two electrodes 21 of the at least one-sided laser diode chip, the at least one conductor through-hole Electrically conducting the upper conductive layer and the lower conductive layer; two or more metal plates 40 spaced apart from each other and arranged on a plane, wherein a first metal plate 40-1 is arranged under the heat conductive plate and connected to the heat conductive plate The lower conductive layer is in contact, a second metal plate 40-2 is disposed adjacent to and separated from the first metal plate, the second metal plate is connected to the other pole 212 of the two electrodes by at least one jumper 50 211 electrical connection; and an insulating frame 60 having an opening 61, disposed above the two or more metal plates, for holding the two or more metal plates, wherein the opening is used for the at least one side-firing laser The laser light emitted by the diode wafer passes through.

In the surface mounting structure of the laser diode of the present invention, the at least one jumper 50 is two jumpers 50-1, 50-2 connected to the other pole of the at least one side-emitting laser diode chip 20 212 or 211, which are symmetrically distributed on the left and right sides of the at least one-sided laser diode wafer.

2(d), the laser diode surface mounting structure 10 of the present invention can be mounted on a printed circuit board 80, including a body 82 and a surface conductor layer 81 plated thereon, wherein The first metal plate 41 is welded to the surface conductor layer 81. Of course, the surface conductor layer 81 can also be used for welding other metal plates.

In addition, in the present invention, please also refer to FIG. 3, the at least one side-fired laser diode chip is plural, and the plurality of side-fired laser diode chips are used for circuit connection, as shown in FIG. 3(a) As shown, it can be a parallel configuration of three laser diode chips 20, or a series configuration of three laser diodes 20 can be shown in FIG. 3(b), of course, various series, Parallel configuration.

In the present invention, the material of the thermally conductive plate 30 is aluminum nitride, aluminum oxide or silicon carbide; and the material of the two or more metal plates is copper; and the material of the insulating frame is plastic, epoxy or electrical wood.

In addition, as shown in FIG. 2, the laser diode surface mounting structure 100 of the present invention may further include at least one additional electronic component 70. The at least one additional electronic component may be a photosensitive diode and an anti-static diode. Polar body, reverse bias protection diode, capacitor, transistor, integrated circuit or surge suppression capacitor, and the at least one additional electronic component is connected to a third metal plate 40-3 which needs to be connected to the circuit A fourth metal plate 40-4 and a jumper 50-3, the metal plates 40-3 and 40-4 are held by the insulating frame.

In the present invention, both sides of the at least one metal plate 40 have convex hulls located thereon, and the convex hulls on both sides thereof are bilaterally symmetrical with the center line. In addition, the first metal plate 40-1 has an opening 71 (shown in FIG. 4(a)) at the laser light exit end of the at least one side laser diode wafer 20 for laser light to pass through.

As shown in FIG. 4, FIG. 4(a) is a top view, and FIG. 4(b) is a side view of a third metal plate carrying electronic components 70. The laser diode surface mounting structure of the present invention is used to carry the At least one additional electronic component 70, when it is a photosensitive diode, a third metal plate 40-3 connected to it is bent into a slope at a position where the at least one additional electronic component is carried. In addition, as shown in the side view of FIG. 4(b), unlike other metal plates, they are not in the same plane (as shown by the dotted line in FIG. 4(b)). In this embodiment, the light receiving surface of the at least one electronic component is provided. The angle formed by the normal vector and the center line of the back laser light is not 90 degrees. In order to increase the effective light receiving area, it is used to cooperate with a feedback control circuit to stabilize the laser light intensity. The first metal plate 40-1 expands outward to enhance the heat dissipation capability, and has all openings at the laser light exit end for the laser light to pass through.

The surface mounting structure of the laser diode of the present invention may further include an upper cover (not shown in the figure) for covering the insulating frame. The two or more metal plates spaced apart from each other and arranged on a plane are bent (but still on the same plane), as shown in FIG. 4(a), the first metal plate 40-1 and the second metal plate 40-2 The left and right sides are shown to increase the strength of the insulating frame to hold each metal plate.

As shown in FIG. 5, the surface mounting structure of the laser diode of the present invention may further include an optical element 90 installed in front of the edge-emitting laser diode 20, which may be held by the insulating frame or may be held by the insulating frame The upper cover is held, or held by a bendable metal plate, wherein the optical element 90 is a lens, filter, diffraction grating, prism, polarizer, optical crystal, or nonlinear optical crystal, used as required Handle the beam of the edge-emitting laser diode.

Furthermore, in the laser diode surface mounting structure of the present invention, the at least one additional electronic component is a laser light intensity stabilizing circuit.

10‧‧‧Laser diode surface mounting structure

20‧‧‧side-fired laser diode

21‧‧‧Two electrodes

211‧‧‧Anode

212‧‧‧Cathode

30‧‧‧Heat conduction board

31‧‧‧ Upper conductive layer

32‧‧‧Lower conductive layer

33‧‧‧At least one conductor hole

40‧‧‧Metal plate

40-1‧‧‧First metal plate

40-2‧‧‧Second metal plate

40-3‧‧‧third metal plate

40-4‧‧‧The fourth metal plate

50-1, 50-2, 50-3‧‧‧ jumper

60‧‧‧Insulation frame

61‧‧‧ opening

70‧‧‧ additional electronic components

80‧‧‧ printed circuit board

81‧‧‧Surface conductor layer of printed circuit board

82‧‧‧Body of printed circuit board

Claims (18)

A laser diode surface mounting structure includes: at least one side-fired laser diode chip, including two electrodes having an anode and a cathode; a thermally conductive plate having an upper conductive layer, a lower conductive layer, and at least A conductor through-hole penetrating the upper conductive layer and the lower conductive layer to support one of the two electrodes of the at least one-sided laser diode chip, the at least one conductor through-hole is used to electrically conduct the An upper conductive layer and a lower conductive layer; two or more metal plates spaced apart from each other and arranged on a plane, wherein a first metal plate is arranged below the heat conductive plate and is in contact with the lower conductive layer of the heat conductive plate, a first Two metal plates are arranged adjacent to and separated from the first metal plate, the second metal plate is electrically connected to the other electrode of the two electrodes through at least one jumper; and an insulating frame with an opening is provided on the Above the two or more metal plates are used to hold the two or more metal plates, wherein the opening is used for the laser light emitted by the at least one side-fired laser diode chip to pass through. For example, the surface mounting structure of a laser diode according to item 1 of the patent application, wherein the at least one jumper is two jumpers connected to the other pole of the at least one side-emitting laser diode chip, which is symmetrically distributed The at least one side laser diode wafer is overlapped in a manner of left and right sides. For example, as for the surface mounting structure of a laser diode of claim 1, the plurality of at least one side-emitting laser diode chips are plural, and the plurality of side-emitting laser diode chips are used for circuit connection, And wherein the circuit connection is series, parallel or a combination thereof. For example, the surface mounting structure of the laser diode of the first patent application, wherein the material of the heat conducting plate is aluminum nitride, aluminum oxide or silicon carbide. For example, the surface mounting structure of the laser diode in the first scope of the patent application, wherein the material of the two or more metal plates is copper. For example, the surface mounting structure of the laser diode of the first patent application, wherein the material of the insulating frame is plastic, epoxy resin or bakelite. For example, the surface mounting structure of the laser diode in the first scope of the patent application further includes at least one additional electronic component. For example, the surface mounting structure of the laser diode of the 7th patent application, wherein the at least one additional electronic component is a photosensitive diode, anti-static diode, reverse bias protection diode, capacitor, transistor , An integrated circuit or a surge suppression capacitor, and the at least one additional electronic component is connected to a metal plate that needs to be connected to the circuit, and the metal plate that is connected to the circuit is held by the insulating frame. For example, the surface mounting structure of a laser diode according to item 1 of the patent application, wherein the at least one metal plate has a convex hull thereon. For example, the surface mounting structure of a laser diode according to item 1 of the patent application, wherein the first metal plate has all openings at the exit end of the at least one-sided laser diode wafer for the passage of laser light. For example, the laser diode surface mounting structure of claim 8 of the patent application, wherein the metal plate connected to carry the at least one additional electronic component is inclined at a position where the at least one additional electronic component is carried, for the The angle formed by the normal vector of the light-receiving surface of at least one electronic component and the center line of the back laser light is not 90 degrees. For example, the surface mounting structure of the laser diode in the first scope of the patent application, and further includes an upper cover to cover the insulating frame. For example, the surface mounting structure of a laser diode according to item 1 of the patent application, wherein the two or more metal plates spaced apart from each other and arranged on a plane have a bend to increase the strength of the insulating frame to hold the metal plates. For example, the surface mounting structure of the laser diode of the first patent application scope further includes an optical element, which is held by the insulating frame. For example, the surface mounting structure of the laser diode in the first scope of the patent application further includes an optical element, which is held by the upper cover. For example, the surface mounting structure of the laser diode of the first patent application scope further includes an optical element, which is held by a bendable metal plate. For example, the surface mounting structure of the laser diode of item 14, 15 or 16, wherein the optical element is a lens, filter, diffraction grating, prism, polarizer, optical crystal, or nonlinear optical crystal . For example, the surface mounting structure of the laser diode of the first patent application includes a printed circuit board with a body and a surface conductor layer on the body, wherein the first metal plate is connected to the surface conductor layer on.

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