Semiconductor laser package and module

Abstract

Provided in the present invention are a semiconductor laser package and module. The package and module comprises leads, a base, a tab, a heat sink and a laser; a packaging form is at least one of a plastic package and module, a transistor outline-can (TO-CAN) package and module, and a chip-on-submount (COS) package and module; and the package and module has a thermal conductivity coefficient gradient, the thermal conductivity coefficient of the base is a, the thermal conductivity coefficient of the tab is b, the thermal conductivity coefficient of the heat sink is c, the thermal conductivity coefficient of the laser is d, and the thermal conductivity coefficient gradient is one of d≤a≤b≤c, d≤a≤c≤b, a≤d≤b≤c and a≤d≤c≤b.

Description

A semiconductor laser package and module Technical Field

[0001] This specification relates to the field of semiconductor optoelectronic devices, and in particular to a semiconductor laser package and module. Background Technology

[0002] Lasers are widely used in laser displays, laser TVs, laser projectors, communications, medical applications, weaponry, guidance, ranging, spectral analysis, cutting, precision welding, and high-density optical storage. There are many types of lasers, mainly including solid-state, gas, liquid, semiconductor, and dye lasers. Compared to other types of lasers, all-solid-state semiconductor lasers have advantages such as small size, high efficiency, light weight, good stability, long lifespan, simple and compact structure, and miniaturization. Devices with similar functions to lasers include semiconductor light-emitting diodes, such as nitride semiconductor light-emitting diodes. However, there are significant differences between lasers and nitride semiconductor light-emitting diodes (LEDs), including: (1) Lasers are generated by stimulated emission of charge carriers, with a small half-width at half-maximum (FW) of the spectrum and very high brightness. The output power of a single laser can be in the W range, while nitride semiconductor LEDs are generated by spontaneous emission, with the output power of a single LED in the mW range; (2) The operating current density of lasers reaches KA / cm2, which is more than two orders of magnitude higher than that of nitride LEDs, resulting in stronger electron leakage, more severe Auger recombination, stronger polarization effect, and more severe electron-hole mismatch, leading to more severe efficiency degradation and the Droop effect; (3) The spontaneous transition radiation of the light-emitting diode is incoherent light that transitions from a high energy level to a low energy level without external influence. The laser, on the other hand, is stimulated transition radiation. The energy of the induced photon should be equal to the energy difference of the electron transition, and the photon and the induced photon are coherent light. (4) The principles are different: the light-emitting diode emits radiation and recombines light under the action of external voltage, and the electron-hole transition to the active layer or pn junction to produce radiative recombination. The laser, however, requires the lasing condition to be met before it can emit light. It must satisfy the inversion distribution of the charge carriers in the active region. The stimulated emission light oscillates back and forth in the resonant cavity. The propagation in the gain medium amplifies the light. The threshold condition is satisfied so that the gain is greater than the loss, and finally the laser is output.

[0003] Summary of the Invention

[0004] To address the aforementioned problems, the present invention aims to provide a semiconductor laser package and module. By designing multiple parameter gradients between various components in the semiconductor laser package and module, as well as the parameter values ​​of each component, the thermal conductivity uniformity, thermal stress distribution uniformity, and other properties of the semiconductor laser are improved, resulting in a semiconductor laser package and module with superior performance and longer lifespan.

[0005] This specification provides one or more embodiments of a semiconductor laser package and module, the package and module including pins, sockets, tongues, heat sinks, and a laser; the packaging form includes at least one of plastic encapsulation, TO-CAN (Transistor Outline) can-type package and module, and COS (Chip-on-Submount) package and module; the package and module have a thermal conductivity gradient, the thermal conductivity of the socket is a, the thermal conductivity of the tongue is b, the thermal conductivity of the heat sink is c, and the thermal conductivity of the laser is d, wherein the thermal conductivity gradient is one of d≤a≤b≤c, d≤a≤c≤b, a≤d≤b≤c, and a≤d≤c≤b.

[0006] This specification provides one or more embodiments of a semiconductor laser package and module, the package and module including a cap, a housing, and a Zener tube; the materials of the tongue, the base, the cap, and the housing include any one or more combinations of Cu, Al, Ag, Au, chromium, nickel, C, stainless steel, Pd, Ti, Zr, Ta, Nb, V, Hf, Ga, Fe, Si, P, Cu-plated Ni, Cu-plated Pd, Cu-plated Ni / Pd, Fe-plated Ni, Fe-plated Pd, Fe-plated Ni / Pd, iron-clad copper-plated Ni, iron-clad copper-plated Pd, iron-clad copper-plated Ni / Pd, Cu-plated Pd / Ni, Fe-plated Pd / Ni, iron-clad copper-plated Pd / Ni, Kovar-plated Pd, Kovar-plated Ni, Kovar-plated Ni / Pd, Kovar-plated Pd / Ni, CuW, BeO, Kovar, Fe, Cu-Fe-Cu composite material, Cu-Fe composite material, Cu-Al composite material, and iron-clad copper.

[0007] This specification provides one or more embodiments of a semiconductor laser package and module. The heat sink material includes SiC, Cu-SiC composite structure, Cu-SiC-AuSn, Cu-SiC-Cu composite structure, Cu-AlN composite structure, Cu-AlN-Cu composite structure, Cu-AlN-AuSn, AuSn, AlN, diamond, Cu-diamond composite structure, Cu-diamond-Cu composite structure, Cu-diamond-AuSn composite structure, AlN single-sided copper clad structure, AlN double-sided copper clad structure, SiC single-sided copper clad structure, SiC double-sided copper clad structure, diamond single-sided copper clad structure, diamond double-sided copper clad structure, Ti, Zr, Ta, Nb, V, Hf, AlN / Zr / Cu composite structure, AlN / Ta / Cu composite structure, AlN / Nb / Cu composite structure, AlN / V / Cu composite structure, AlN / Hf / Cu composite structure. The laser is any one or more of the following: AlN / Zr / Nb / Cu composite structure, AlN / Nb / V / Cu composite structure, Si, CuW, TiW, Cu, BeO, GaN, GaAs, InP, and Mo; the laser is at least one of gallium nitride-based laser, gallium arsenide-based laser, indium phosphorus-based laser, aluminum nitride-based laser, and InGaN-based laser; and the wavelength range of the laser is 200 nm to 3000 nm.

[0008] This specification provides one or more embodiments of a semiconductor laser package and module, wherein the thermal conductivity of the socket is in the range of 50 to 500 W / (m*K), the thermal conductivity of the tongue is in the range of 100 to 600 W / (m*K), the thermal conductivity of the heat sink is in the range of 130 to 5000 W / (m*K), and the thermal conductivity of the laser is in the range of 20 to 300 W / (m*K).

[0009] This specification provides one or more embodiments of a semiconductor laser package and module, the package and module having a thermal resistance coefficient gradient, wherein the thermal resistance coefficient of the socket is e, the thermal resistance coefficient of the tongue is f, the thermal resistance coefficient of the heat sink is g, and the thermal resistance coefficient of the laser is h, wherein the thermal resistance coefficient gradient is one of g≤f≤e≤h or g≤f≤h≤e or f≤g≤e≤h or f≤g≤h≤e.

[0010] This specification provides one or more embodiments of a semiconductor laser package and module, the package and module having a relative permittivity gradient, wherein the relative permittivity of the socket is j, the relative permittivity of the tongue is k, the relative permittivity of the heat sink is m, and the relative permittivity of the laser is n, wherein the relative permittivity gradient is one of k≤j≤m≤n, j≤k≤m≤n, k≤j≤n≤m, or j≤k≤n≤m.

[0011] This specification provides one or more embodiments of a semiconductor laser package and module, the package and module having a high-frequency dielectric constant gradient, wherein the high-frequency dielectric constant of the socket is p, the high-frequency dielectric constant of the tongue is q, the high-frequency dielectric constant of the heat sink is r, and the high-frequency dielectric constant of the laser is s, wherein the high-frequency dielectric constant gradient is one of q≤p≤r≤s, p≤q≤r≤s, q≤p≤s≤r, or p≤q≤s≤r.

[0012] This specification provides one or more embodiments of a semiconductor laser package and module, the package and module having a gradient of thermal expansion coefficients, wherein the thermal expansion coefficient of the socket is t, the thermal expansion coefficient of the tongue is u, the thermal expansion coefficient of the heat sink is v, and the thermal expansion coefficient of the laser is w, wherein v≤w≤t≤u; and the thermal expansion coefficient of the socket is in the range of 5*10-6~15*10-6 / K, the thermal expansion coefficient of the tongue is 8*10-6~20*10-6 / K, the thermal expansion coefficient of the heat sink is 0.5*10-6~8*10-6 / K, and the thermal expansion coefficient of the laser is 1.5*10-6~15*10-6 / K.

[0013] This specification provides one or more embodiments of a semiconductor laser package and module. The laser includes a laser chip, wherein the longitudinal sound velocity of the laser chip is not greater than the longitudinal sound velocity of the nozzle, and the longitudinal sound velocity of the laser chip is not greater than the longitudinal sound velocity of the heat sink; the transverse sound velocity of the laser chip is not greater than the transverse sound velocity of the nozzle, and the transverse sound velocity of the laser chip is not greater than the transverse sound velocity of the heat sink; the thermal conductivity of the laser chip is not greater than the thermal conductivity of the nozzle, and the thermal conductivity of the laser chip is not greater than the thermal conductivity of the heat sink; and the absorption coefficient of the laser chip is not greater than the absorption coefficient of the nozzle, and the absorption coefficient of the laser chip is not greater than the absorption coefficient of the heat sink.

[0014] This specification provides one or more embodiments of a semiconductor laser package and module, wherein the electron mobility of the laser chip is not less than the electron mobility of the nozzle, and the electron mobility of the laser chip is not less than the electron mobility of the heat sink; the hole mobility of the laser chip is not less than the hole mobility of the nozzle, and the hole mobility of the laser chip is not less than the hole mobility of the heat sink; the electron diffusion constant of the laser chip is not less than the electron diffusion constant of the nozzle, and the electron diffusion constant of the laser chip is not less than the electron diffusion constant of the heat sink; and the hole diffusion coefficient of the laser chip is not less than the hole diffusion coefficient of the nozzle, and the hole diffusion coefficient of the laser chip is not less than the hole diffusion coefficient of the heat sink.

[0015] This specification provides one or more embodiments of a semiconductor laser package and module, wherein the elastic modulus of the laser chip is not less than the elastic modulus of the nozzle, and the elastic modulus of the laser chip is not greater than the elastic modulus of the heat sink; and the elastic modulus of the nozzle is in the range of 50 to 250 GPa, the elastic modulus of the laser chip is in the range of 100 to 400 GPa, and the elastic modulus of the heat sink is in the range of 250 to 1000 GPa.

[0016] This specification provides one or more embodiments of a semiconductor laser package and module, wherein the breakdown field strength of the laser chip is not less than the breakdown field strength of the heat sink; the static dielectric constant of the laser chip is not less than the static dielectric constant of the heat sink; the electron drift velocity of the laser chip is not less than the electron drift velocity of the heat sink; the line diffusion coefficient of the laser chip is not greater than the line diffusion coefficient of the heat sink, and the line diffusion coefficient of the laser chip is not less than the line diffusion coefficient of the nozzle; the density of the nozzle is not less than the density of the laser chip, and the density of the laser chip is not less than the density of the heat sink; and the intrinsic carrier concentration of the laser chip is not less than the intrinsic carrier concentration of the heat sink.

[0017] The beneficial effects of the embodiments of the present invention include at least the following: (1) designing the thermal conductivity gradient and thermal resistance gradient of the semiconductor laser package and module to form a uniform heat conduction channel, reducing bottleneck points, improving the thermal uniformity of the laser package and module, improving heat dissipation performance and heat conduction efficiency, reducing heat accumulation and junction temperature rise of the laser, reducing the temperature and temperature rise rate of the active layer of the laser chip, and improving problems such as laser wavelength redshift, power reduction, and increased threshold current; (2) designing the thermal expansion coefficient gradient, relative permittivity gradient, and high-frequency permittivity gradient of the semiconductor laser package and module to improve the uniformity of temperature distribution and thermal expansion coefficient of the laser, improve the uniformity of thermal expansion and thermal stress distribution, improve problems such as laser temperature quenching, COD optical catastrophic damage, laser breakage, and aging dead lamp, and reduce thermal lensing effect and stress birefringence effect. (2) Improve laser beam depolarization and distortion, and enhance the far-field FFP image quality and beam quality factor of the laser; (3) Design the longitudinal sound velocity, transverse sound velocity, thermal conductivity and absorption coefficient of the laser chip, tongue and heat sink of the semiconductor laser package and module, enhance the group velocity of low frequency phonons, improve the phonon transport efficiency of lattice vibration, improve the Kink torsion current value and saturated laser power current value of the laser's Power-Current curve, and improve the high current and high power driving performance of the laser; (4) Design the electron mobility, hole mobility, electron diffusion constant and hole diffusion constant of the laser chip, tongue and heat sink of the semiconductor laser package and module, improve photon degeneracy and accelerate stimulated emission to exceed spontaneous emission, reduce the rise of laser threshold current during aging process, and reduce the relaxation time of the laser module. Time, reduce phonon scattering probability, improve the thermal decay and aging leakage ratio of laser; (5) design the elastic modulus, density and linear diffusion coefficient of the tongue, heat sink and laser chip of semiconductor laser package and module, improve the strain matching degree of tongue, heat sink and laser chip, reduce the ratio of laser breakage and gold wire breakage, gold wire fall-off, and reduce the abnormal ratio of heat sink fall-off, bubbling and warping; (6) design the static dielectric constant, breakdown field strength, electron drift velocity and intrinsic carrier concentration of the tongue, heat sink and laser chip of semiconductor laser package and module, improve the laser module's resistance to electrostatic breakdown ESD. Attached Figure Description

[0018] This specification will be further described by way of exemplary embodiments, which will be described in detail with reference to the accompanying drawings. These embodiments are not limiting; in these embodiments, the same reference numerals denote the same structures, wherein:

[0019] Figure 1 is one of the structural schematic diagrams of a semiconductor laser package and module according to some embodiments of this specification;

[0020] Figure 2 is a second schematic diagram of the structure of a semiconductor laser package and module according to some embodiments of this specification;

[0021] Figure 3 is a third schematic diagram of the structure of a semiconductor laser package and module according to some embodiments of this specification. Detailed Implementation

[0022] To more clearly illustrate the technical solutions of the embodiments in this specification, the accompanying drawings used in the description of the embodiments will be briefly introduced below. The accompanying drawings do not represent all implementation methods.

[0023] It should be understood that the terms "system," "device," "unit," and / or "module" used herein are a method of distinguishing different components, elements, parts, sections, or assemblies at different levels. If other terms can achieve the same purpose, they may be replaced by other expressions.

[0024] This specification provides some embodiments of a semiconductor laser package and module, the package and module including pins, sockets, tongues, heat sinks and lasers.

[0025] Figure 1 is one of the structural schematic diagrams of a semiconductor laser package and module according to some embodiments of this specification; Figure 2 is another structural schematic diagram of a semiconductor laser package and module according to some embodiments of this specification; Figure 3 is a third structural schematic diagram of a semiconductor laser package and module according to some embodiments of this specification.

[0026] In some embodiments, as shown in Figures 1 and 2, the package and module include pins 100, sockets 101, tongues 102, heat sinks 103, and lasers 104.

[0027] In some embodiments, the packaging form of the package and module may include at least one of the following: plastic package and module, TO-CAN (Transistor Outline) can package and module, and COS (Chip-on-Submount) package and module.

[0028] Pin 100 is configured to connect the internal and external circuitry of the integrated circuit. In some embodiments, the package and module can be connected to the external circuitry via pin 100 to receive and / or output signals or data, or to obtain electrical energy.

[0029] In some embodiments, the pin 100 may be disposed on one side surface of the socket 101. In some embodiments, the pin 100 may be connected to the socket 101 by any feasible connection method, such as welding, bonding, etc.

[0030] In some embodiments, the material of pin 100 may include metal, alloy, etc. For example, silver-plated copper wire and tin-plated copper wire.

[0031] In some embodiments, pin 100 can be in various forms. For example, pin 100 can be either two-pin or three-pin. By way of example only, the pin 100 shown in FIG1 is a two-pin, and the pin 100 shown in FIG2 is a three-pin.

[0032] The tube seat 101 is configured to secure the tube tongue 102 and the tube foot 101. In some embodiments, the tube tongue 102 may also be connected to the tube seat 101 by any feasible connection method, such as welding or bonding.

[0033] The tongue 102 is configured to fix the heat sink 103 and the laser 104. In some embodiments, the tongue 102 may be disposed on the other side surface of the tube seat 101. In some embodiments, the pin 100 and the tongue 102 may be disposed on different sides of the surface of the tube seat 101, respectively.

[0034] In some embodiments, the tongue 102 can be connected to the heat sink 103 by any feasible connection method, such as welding, bonding, etc.

[0035] The materials of the tube seat 101 and the tube tongue 102 can include a variety of materials. In some embodiments, the materials of the tube seat 101 and the tube tongue 102 can include any one or more combinations of Cu, Al, Ag, Au, chromium, nickel, C, stainless steel, Pd, Ti, Zr, Ta, Nb, V, Hf, Ga, Fe, Si, P, Cu plated with Ni, Cu plated with Pd, Cu plated with Ni / Pd, Fe plated with Ni, Fe plated with Pd, Fe plated with Ni / Pd, iron-clad copper plated with Ni, iron-clad copper plated with Pd, iron-clad copper plated with Ni / Pd, Cu plated with Pd / Ni, Fe plated with Pd / Ni, iron-clad copper plated with Pd / Ni, Kovar plated with Pd, Kovar plated with Ni, Kovar plated with Ni / Pd, Kovar plated with Pd / Ni, CuW, BeO, Kovar, Fe, Cu-Fe-Cu composite material, Cu-Fe composite material, Cu-Al composite material, and iron-clad copper.

[0036] The heat sink 103 is configured to help the laser dissipate or transfer heat. In some embodiments, the heat sink 103 may be disposed between the tongue 102 and the laser 104 to prevent heat from being transferred to the tongue 102 and causing damage to the tongue 102.

[0037] The heat sink 103 can be made of various materials. In some embodiments, the heat sink 103 can be made of SiC, Cu-SiC composite structure, Cu-SiC-AuSn, Cu-SiC-Cu composite structure, Cu-AlN composite structure, Cu-AlN-Cu composite structure, Cu-AlN-AuSn, AuSn, AlN, diamond, Cu-diamond composite structure, Cu-diamond-Cu composite structure, Cu-diamond-AuSn composite structure, AlN single-sided copper clad, AlN double-sided copper clad, SiC single-sided copper clad, SiC double-sided copper clad Copper, single-sided copper-clad diamond, double-sided copper-clad diamond, Ti, Zr, Ta, Nb, V, Hf, AlN / Zr / Cu composite structure, AlN / Ta / Cu composite structure, AlN / Nb / Cu composite structure, AlN / V / Cu composite structure, AlN / Hf / Cu composite structure, AlN / Zr / Nb / Cu composite structure, AlN / Nb / V / Cu composite structure, Si, CuW, TiW, Cu, BeO, GaN, GaAs, InP, Mo, any one or more combinations thereof.

[0038] The 103-packaged semiconductor laser with a heat sink made of one or more of the above materials can effectively improve heat dissipation, reduce thermal resistance, increase laser output power, and extend laser life.

[0039] Laser 104 is configured to emit laser light. Laser 104 includes a laser chip. The laser chip is configured to convert electrical energy into laser energy.

[0040] In some embodiments, the laser 104 can be connected to the tongue 102 via a heat sink 103.

[0041] In some embodiments, laser 104 may include at least one of gallium nitride-based laser, gallium arsenide-based laser, indium phosphorus-based laser, aluminum nitride-based laser, and InGaN-based laser.

[0042] In some embodiments, the wavelength range of the laser 104 can be 200 nm to 3000 nm. In some embodiments, the wavelength range of the laser 104 can be 300 nm to 3000 nm. In some embodiments, the wavelength range of the laser 104 can be 500 nm to 2700 nm. In some embodiments, the wavelength range of the laser 104 can be 700 nm to 2500 nm. In some embodiments, the wavelength range of the laser 104 can be 1000 nm to 2300 nm. In some embodiments, the wavelength range of the laser 104 can be 1200 nm to 2100 nm.

[0043] In some embodiments, as shown in FIG3, the package and module may further include a cap (not shown in the figure), a housing 105, and a Zener tube 106.

[0044] The housing 105 is configured to enclose and protect the tongue 102, heat sink 103, Zener tube 106, and laser 104. In some embodiments, the housing 105 can be fixed to the surface of the tube seat on the same side as the tongue 102 by any feasible connection method, such as welding, bonding, etc.

[0045] The cap is configured to seal the housing 105. In some embodiments, the cap may be fitted around the housing 105 and connected to the seat 100 by any feasible connection method, such as welding or bonding.

[0046] Zener diode 106 is configured to stabilize the voltage of the laser. In some embodiments, Zener diode 106 can be disposed on the side of heat sink 103 away from tongue 102 by any feasible connection method. For example, welding, bonding, etc.

[0047] The materials of the cap and shell 105 can include a variety of materials. In some embodiments, the materials of the cap and shell 105 can include any one or more combinations of Cu, Al, Ag, Au, chromium, nickel, C, stainless steel, Pd, Ti, Zr, Ta, Nb, V, Hf, Ga, Fe, Si, P, Cu plated with Ni, Cu plated with Pd, Cu plated with Ni / Pd, Fe plated with Ni, Fe plated with Pd, Fe plated with Ni / Pd, iron-clad copper plated with Ni, iron-clad copper plated with Pd, iron-clad copper plated with Ni / Pd, Cu plated with Pd / Ni, Fe plated with Pd / Ni, iron-clad copper plated with Pd / Ni, Kovar plated with Pd, Kovar plated with Ni, Kovar plated with Ni / Pd, Kovar plated with Pd / Ni, CuW, BeO, Kovar, Fe, Cu-Fe-Cu composite material, Cu-Fe composite material, Cu-Al composite material, and iron-clad copper.

[0048] In some embodiments, the package and module have a thermal conductivity gradient. The thermal conductivity gradient can characterize the rate of change of the thermal conductivity of each component in the package and module.

[0049] In some embodiments, the thermal conductivity of the tube seat 101 is a, the thermal conductivity of the tube tongue 102 is b, the thermal conductivity of the heat sink 103 is c, and the thermal conductivity of the laser 104 is d. The thermal conductivity gradient can be one of d≤a≤b≤c, d≤a≤c≤b, a≤d≤b≤c, or a≤d≤c≤b.

[0050] In some embodiments, the thermal conductivity of the tube seat 101 can be in the range of 50 to 500 W / (m*K), the thermal conductivity of the tube tongue 102 can be in the range of 100 to 600 W / (m*K), the thermal conductivity of the heat sink 103 can be in the range of 130 to 5000 W / (m*K), and the thermal conductivity of the laser 104 can be in the range of 20 to 300 W / (m*K).

[0051] In some embodiments, the package and module have a thermal resistance gradient. The thermal resistance gradient can characterize the rate of change of the thermal resistance of each component in the package and module.

[0052] In some embodiments, the thermal resistance coefficient of the tube seat 101 is e, the thermal resistance coefficient of the tube tongue 102 is f, the thermal resistance coefficient of the heat sink 103 is g, and the thermal resistance coefficient of the laser 104 is h. The thermal resistance coefficient gradient can be one of g≤f≤e≤h, g≤f≤h≤e, f≤g≤e≤h, or f≤g≤h≤e.

[0053] Heat loss can cause thermal expansion and uneven distribution of thermal stress, leading to temperature quenching, laser breakage, thermal lensing effect, and stress birefringence. Meanwhile, nonradiative recombination loss and free carrier absorption in the active region of the laser chip generate a large amount of heat. The epitaxial layer and chip material have resistance, which will generate Joule heat loss and carrier absorption loss under current injection. Furthermore, the low thermal conductivity of the chip material and poor heat dissipation performance will lead to an increase in the temperature of the active layer, resulting in problems such as redshift of the lasing wavelength, decrease in quantum efficiency, decrease in power, increase in threshold current, shorter lifetime, and deterioration in reliability.

[0054] In some embodiments of this specification, by designing the thermal conductivity gradient and thermal resistance gradient between the semiconductor laser package and the module, a uniform heat conduction channel can be formed, reducing bottleneck points and improving the heat conduction uniformity of the laser package and module system. This enhances heat dissipation performance and heat conduction efficiency, reduces heat accumulation and junction temperature rise in the laser, lowers the temperature and temperature rise rate of the active layer of the laser chip, and improves problems such as laser wavelength redshift, power reduction, and increased threshold current. As a result, the laser's 10,000-hour aging optical decay is reduced from 20-60% to 2-20%.

[0055] Thermal loss refers to the Stokes shift loss caused by the photon energy difference between the pump light and the oscillating light, which is converted into heat, and the energy loss due to the non-uniform coupling ratio between the pump level and the upper laser level, which is also converted into heat. Both together generate a large amount of waste heat, which can cause uneven temperature distribution in the laser, leading to thermal expansion and uneven thermal stress distribution. This can result in temperature quenching, laser breakage, thermal lensing, and stress birefringence. Thermal lensing refers to a lens-like phenomenon in space, while stress birefringence alters the polarization state of the incident light, causing depolarization and distortion of the laser beam.

[0056] In some embodiments, the package and module have a relative permittivity gradient. The relative permittivity gradient can characterize the rate of change of the relative permittivity of each component in the package and module.

[0057] In some embodiments, the relative permittivity of the tube seat 101 is j, the relative permittivity of the tube tongue 102 is k, the relative permittivity of the heat sink 103 is m, and the relative permittivity of the laser 104 is n. The relative permittivity gradient can be one of k≤j≤m≤n, j≤k≤m≤n, k≤j≤n≤m, or j≤k≤n≤m.

[0058] In some embodiments, the package and module have a high-frequency dielectric constant gradient. The high-frequency dielectric constant gradient can characterize the rate of change of the high-frequency dielectric constant of each component in the package and module.

[0059] In some embodiments, the high-frequency dielectric constant of the tube socket 101 is p, the high-frequency dielectric constant of the tube tongue 102 is q, the high-frequency dielectric constant of the heat sink 103 is r, and the high-frequency dielectric constant of the laser 104 is s. The high-frequency dielectric constant gradient can be one of q≤p≤r≤s, p≤q≤r≤s, q≤p≤s≤r, or p≤q≤s≤r.

[0060] In some embodiments, the package and module have a gradient of thermal expansion coefficients. The gradient of thermal expansion coefficients can characterize the rate of change of the thermal expansion coefficients of the various components in the package and module.

[0061] In some embodiments, the coefficient of thermal expansion of the tube seat 101 is t, the coefficient of thermal expansion of the tube tongue 102 is u, the coefficient of thermal expansion of the heat sink 103 is v, and the coefficient of thermal expansion of the laser 104 is w. The gradient of the coefficient of thermal expansion can be v≤w≤t≤u.

[0062] In some embodiments, the coefficient of thermal expansion of the tube seat 101 can be in the range of 5*10-6 to 15*10-6 / K, the coefficient of thermal expansion of the tube tongue 102 can be 8*10-6 to 20*10-6 / K, the coefficient of thermal expansion of the heat sink 103 can be 0.5*10-6 to 8*10-6 / K, and the coefficient of thermal expansion of the laser 104 can be 1.5*10-6 to 15*10-6 / K.

[0063] In some embodiments of this specification, by designing the gradients of the coefficient of thermal expansion, relative permittivity, and high-frequency permittivity of the semiconductor laser package and module, the uniformity of temperature distribution and coefficient of thermal expansion of the laser can be improved, the uniformity of thermal expansion and thermal stress distribution can be improved, and problems such as temperature quenching, COD optical catastrophic damage, laser breakage, and aging dead lamps can be mitigated. In addition, the thermal lensing effect and stress birefringence effect can be reduced, the laser beam depolarization and distortion can be improved, and the far-field FFP image quality and beam quality factor of the laser can be enhanced.

[0064] In some embodiments, the longitudinal sound velocity of the laser chip is not greater than the longitudinal sound velocity of the nozzle 102, and the longitudinal sound velocity of the laser chip is not greater than the longitudinal sound velocity of the heat sink 103. The longitudinal sound velocity refers to the propagation speed of the longitudinal wave in the sound wave.

[0065] In some embodiments, the transverse sound velocity of the laser chip is not greater than the transverse sound velocity of the nozzle 102, and the transverse sound velocity of the laser chip is not greater than the transverse sound velocity of the heat sink 103. Transverse sound velocity refers to the propagation speed of transverse waves in sound waves.

[0066] In some embodiments, the thermal conductivity of the laser chip is not greater than that of the tongue 102, and the thermal conductivity of the laser chip is not greater than that of the heat sink 103. Thermal conductivity characterizes the ability to transfer heat.

[0067] In some embodiments, the absorption coefficient of the laser chip is not greater than the absorption coefficient of the nozzle 102, and the absorption coefficient of the laser chip is not greater than the absorption coefficient of the heat sink 103. The absorption coefficient can characterize the ability to absorb light.

[0068] Because lasers generate a large amount of non-radiative recombination heat when used at high current densities, they cause problems such as low Kink distortion current values ​​and low saturation laser power current values ​​in the laser's Power-Current curve, as well as excessive thermal decay and aging leakage current.

[0069] In some embodiments of this specification, by designing the longitudinal sound velocity, transverse sound velocity, thermal conductivity, and absorption coefficient of the laser chip, nozzle, and heat sink in the laser package and module, the group velocity of low-frequency phonons can be enhanced, the phonon transport efficiency of lattice vibrations can be improved, the Kink torsion current value and the saturated laser power current value of the laser's Power-Current curve can be increased, and the high-current and high-power driving performance of the laser can be improved.

[0070] In some embodiments, the electron mobility of the laser chip is not less than that of the nozzle 102, and the electron mobility of the laser chip is not less than that of the heat sink 103. Electron mobility characterizes how fast electrons move under the influence of an electric field.

[0071] In some embodiments, the hole mobility of the laser chip is not less than the hole mobility of the nozzle 102, and the hole mobility of the laser chip is not less than the hole mobility of the heat sink 103. Hole mobility can characterize how fast a hole moves under the influence of an electric field.

[0072] In some embodiments, the electron diffusion constant of the laser chip is not less than the electron diffusion constant of the nozzle 102, and the electron diffusion constant of the laser chip is not less than the electron diffusion constant of the heat sink 103. The electron diffusion constant can characterize the degree of electron diffusion in a substance.

[0073] In some embodiments, the hole diffusion coefficient of the laser chip is not less than the hole diffusion coefficient of the nozzle 102, and the hole diffusion coefficient of the laser chip is not less than the hole diffusion coefficient of the heat sink 103. The hole diffusion coefficient can characterize the degree of hole diffusion in a material.

[0074] In some embodiments of this specification, by designing the electron mobility, hole mobility, electron diffusion constant, and hole diffusion constant of the laser chip, nozzle, and heat sink in the laser package and module, photon degeneracy can be improved and stimulated emission can be accelerated to exceed spontaneous emission. This reduces the rise in laser threshold current during the aging process, decreasing the rise in aging threshold current from 50-80% to 10-40% over 10,000 hours. It also reduces the relaxation time of the laser module, lowers the phonon scattering probability, and improves the thermal decay and aging leakage ratio of the laser, decreasing the aging leakage from + / -1 to 5 μA to + / -0 to 1 μA over 10,000 hours.

[0075] In some embodiments, the elastic modulus of the laser chip is not less than the elastic modulus of the tongue 102, and the elastic modulus of the laser chip is not greater than the elastic modulus of the heat sink 103.

[0076] In some embodiments, the elastic modulus of the tongue 102 can be in the range of 50 to 250 GPa, the elastic modulus of the laser chip can be in the range of 100 to 400 GPa, and the elastic modulus of the heat sink 103 can be in the range of 250 to 1000 GPa.

[0077] Because lasers generate a lot of heat when used under high current and high current density, and the heat dissipation of the devices is poor and the temperature characteristics are poor, the stress mismatch of semiconductor laser chips, heat sinks and tube tongues will be aggravated, causing problems such as laser breakage, gold wire breakage, gold wire detachment, heat sink detachment, blistering and warping. At the same time, the laser module’s resistance to electrostatic discharge (ESD) is deviated.

[0078] In some embodiments of this specification, by designing the elastic modulus, density, and linear diffusion coefficient of the laser module's nozzle, heat sink, and laser chip, the strain matching degree of the nozzle, heat sink, and laser chip can be improved, reducing the ratio of laser breakage to gold wire breakage and gold wire detachment. This reduces the abnormal ratio of laser breakage to gold wire breakage and gold wire detachment from 57 PPM to 7 PPM, and also reduces the abnormal ratio of heat sink detachment, blistering, and warping from 32 PPM to 5 PPM.

[0079] In some embodiments, the breakdown field strength of the laser chip is not less than the breakdown field strength of the heat sink 103.

[0080] In some embodiments, the static dielectric constant of the laser chip is not less than the static dielectric constant of the heat sink 103. The static dielectric constant can characterize the response of a material to an electric field.

[0081] In some embodiments, the electron drift velocity of the laser chip is not less than the electron drift velocity of the heat sink 103. Electron drift velocity refers to the average speed at which electrons move in a conductor under the influence of an electric field.

[0082] In some embodiments, the linear diffusion coefficient of the laser chip is not greater than the linear diffusion coefficient of the heat sink 103, and the linear diffusion coefficient of the laser chip is not less than the linear diffusion coefficient of the tongue 102.

[0083] In some embodiments, the density of the tongue 102 is not less than the density of the laser chip, and the density of the laser chip is not less than the density of the heat sink 103.

[0084] In some embodiments, the intrinsic carrier concentration of the laser chip is not less than the intrinsic carrier concentration of the heat sink 103.

[0085] In some embodiments of this specification, designing the laser module's nozzle, heat sink, static dielectric constant, breakdown field strength, electron drift velocity, and intrinsic carrier concentration can improve the laser module's resistance to electrostatic discharge (ESD). The pass rate for human body mode (HBM) ESD is increased from over 90% for 50–200V to over 90% for 200–2KV.

[0086] The following table compares the performance of lasers in some embodiments of this specification with that of conventional lasers:

[0087] In some embodiments of this specification, by designing the polynomial coefficient gradient and constant gradient of the semiconductor laser package and module, as well as the parameters of each component, a semiconductor laser package and module with better performance and longer lifespan can be obtained.

[0088] Furthermore, certain features, structures, or characteristics in one or more embodiments of this specification may be appropriately combined.

[0089] In some embodiments, numbers describing the quantity of components and attributes are used. It should be understood that such numbers used in the description of embodiments are modified in some examples with the terms "approximately," "approximately," or "generally." Unless otherwise stated, "approximately," "approximately," or "generally" indicates that the numbers are allowed to vary by ±20%. Accordingly, in some embodiments, the numerical parameters used in the specification and claims are approximate values, which may be changed depending on the characteristics required by individual embodiments. In some embodiments, numerical parameters should take into account specified significant digits and employ a general method of digit reservation. Although the numerical ranges and parameters used to confirm their breadth of range in some embodiments of this specification are approximate values, in specific embodiments, such values ​​are set as precisely as feasible.

[0090] If there is any inconsistency or conflict between the descriptions, definitions, and / or terms used in the materials referenced in this specification and the content described in this specification, the descriptions, definitions, and / or terms used in this specification shall prevail.

Claims

1. A semiconductor laser package and module, characterized in that, The package and module include pins, sockets, tongues, heat sinks, and lasers; The packaging form includes at least one of the following: plastic package and module, TO-CAN (Transistor Outline) can package and module, and COS (Chip-on-Submount) package and module; The package and module have a thermal conductivity gradient, wherein the thermal conductivity of the socket is a, the thermal conductivity of the tongue is b, the thermal conductivity of the heat sink is c, and the thermal conductivity of the laser is d, wherein the thermal conductivity gradient is one of the following: d≤a≤b≤c, d≤a≤c≤b, a≤d≤b≤c, and a≤d≤c≤b.

2. The package and module as described in claim 1, characterized in that, The package and module also include a tube cap, a tube shell, and a Zener tube; The materials of the tongue, the seat, the cap, and the shell include any one or more combinations of Cu, Al, Ag, Au, chromium, nickel, C, stainless steel, Pd, Ti, Zr, Ta, Nb, V, Hf, Ga, Fe, Si, P, Cu plated with Ni, Cu plated with Pd, Cu plated with Ni / Pd, Fe plated with Ni, Fe plated with Pd, Fe plated with Ni / Pd, iron-clad copper plated with Ni, iron-clad copper plated with Pd, iron-clad copper plated with Ni / Pd, Cu plated with Pd / Ni, Fe plated with Pd / Ni, iron-clad copper plated with Pd / Ni, Kovar plated with Pd, Kovar plated with Ni, Kovar plated with Ni / Pd, Kovar plated with Pd / Ni, CuW, BeO, Kovar, Fe, Cu-Fe-Cu composite material, Cu-Fe composite material, Cu-Al composite material, and iron-clad copper.

3. The package and module as described in claim 1, characterized in that, The heat sink materials include SiC, Cu-SiC composite structure, Cu-SiC-AuSn, Cu-SiC-Cu composite structure, Cu-AlN composite structure, Cu-AlN-Cu composite structure, Cu-AlN-AuSn, AuSn, AlN, diamond, Cu-diamond composite structure, Cu-diamond-Cu composite structure, Cu-diamond-AuSn composite structure, AlN single-sided copper clad, AlN double-sided copper clad, SiC single-sided copper clad, SiC double-sided copper clad, diamond single-sided copper clad, diamond double-sided copper clad, Ti, Zr, Ta, Nb, V, Hf, AlN / Zr / Cu composite structure, AlN / Ta / Cu composite structure, AlN / Nb / Cu composite structure, AlN / V / Cu composite structure, and AlN / Hf / Cu composite structure. AlN / Zr / Nb / Cu composite structure, AlN / Nb / V / Cu composite structure, any one or more combinations of Si, CuW, TiW, Cu, BeO, GaN, GaAs, InP, and Mo; The laser includes at least one of gallium nitride-based lasers, gallium arsenide-based lasers, indium phosphide-based lasers, aluminum nitride-based lasers, and InGaN-based lasers; and The wavelength range of the laser is 200nm to 3000nm.

4. The package and module as described in claim 1, characterized in that, The thermal conductivity of the tube socket ranges from 50 to 500 W / (m*K), the thermal conductivity of the tube tongue ranges from 100 to 600 W / (m*K), the thermal conductivity of the heat sink ranges from 130 to 5000 W / (m*K), and the thermal conductivity of the laser ranges from 20 to 300 W / (m*K).

5. The package and module as described in claim 1, characterized in that, The package and module have a thermal resistance coefficient gradient, wherein the thermal resistance coefficient of the socket is e, the thermal resistance coefficient of the tongue is f, the thermal resistance coefficient of the heat sink is g, and the thermal resistance coefficient of the laser is h, wherein the thermal resistance coefficient gradient is one of g≤f≤e≤h or g≤f≤h≤e or f≤g≤e≤h or f≤g≤h≤e.

6. The package and module as described in claim 1, characterized in that, The package and module have a relative permittivity gradient, wherein the relative permittivity of the socket is j, the relative permittivity of the tongue is k, the relative permittivity of the heat sink is m, and the relative permittivity of the laser is n, wherein the relative permittivity gradient is one of k≤j≤m≤n, j≤k≤m≤n, k≤j≤n≤m, or j≤k≤n≤m.

7. The package and module as described in claim 1, characterized in that, The package and module have a high-frequency dielectric constant gradient, wherein the high-frequency dielectric constant of the socket is p, the high-frequency dielectric constant of the tongue is q, the high-frequency dielectric constant of the heat sink is r, and the high-frequency dielectric constant of the laser is s, wherein the high-frequency dielectric constant gradient is one of q≤p≤r≤s, p≤q≤r≤s, q≤p≤s≤r, or p≤q≤s≤r.

8. The package and module as described in claim 1, characterized in that, The package and module have a gradient in their coefficients of thermal expansion. The coefficient of thermal expansion of the socket is t, the coefficient of thermal expansion of the tongue is u, the coefficient of thermal expansion of the heat sink is v, and the coefficient of thermal expansion of the laser is w, where: v ≤ w ≤ t ≤ u; and The thermal expansion coefficient of the tube seat is in the range of 5*10. -6 ~15*10 -6 / K, the coefficient of thermal expansion of the tongue is 8*10. -6 ~20*10 -6 / K, the coefficient of thermal expansion of the heat sink is 0.5*10 -6 ~8*10 -6 / K, the coefficient of thermal expansion of the laser is 1.5*10. -6 ~15*10 -6 / K.

9. The package and module as described in claim 1, characterized in that, The laser includes a laser chip, the longitudinal sound velocity of the laser chip is not greater than the longitudinal sound velocity of the tube tongue, and the longitudinal sound velocity of the laser chip is not greater than the longitudinal sound velocity of the heat sink. The lateral sound velocity of the laser chip is not greater than the lateral sound velocity of the tube tongue, and the lateral sound velocity of the laser chip is not greater than the lateral sound velocity of the heat sink. The thermal conductivity of the laser chip is not greater than that of the nozzle, and the thermal conductivity of the laser chip is not greater than that of the heat sink; and The absorption coefficient of the laser chip is not greater than the absorption coefficient of the tube tongue, and the absorption coefficient of the laser chip is not greater than the absorption coefficient of the heat sink.

10. The package and module as described in claim 1, characterized in that, The electron mobility of the laser chip is not less than that of the tube tongue, and the electron mobility of the laser chip is not less than that of the heat sink. The hole mobility of the laser chip is not less than the hole mobility of the tube tongue, and the hole mobility of the laser chip is not less than the hole mobility of the heat sink. The electron diffusion constant of the laser chip is not less than the electron diffusion constant of the nozzle, and the electron diffusion constant of the laser chip is not less than the electron diffusion constant of the heat sink; and The hole diffusion coefficient of the laser chip is not less than the hole diffusion coefficient of the nozzle, and the hole diffusion coefficient of the laser chip is not less than the hole diffusion coefficient of the heat sink.

11. The package and module as described in claim 1, characterized in that, The elastic modulus of the laser chip is not less than the elastic modulus of the nozzle, and the elastic modulus of the laser chip is not greater than the elastic modulus of the heat sink; and The elastic modulus of the tube tongue ranges from 50 to 250 GPa, the elastic modulus of the laser chip ranges from 100 to 400 GPa, and the elastic modulus of the heat sink ranges from 250 to 1000 GPa.

12. The package and module as described in claim 1, characterized in that, The breakdown field strength of the laser chip is not less than the breakdown field strength of the heat sink. The static dielectric constant of the laser chip is not less than the static dielectric constant of the heat sink; The electron drift velocity of the laser chip is not less than the electron drift velocity of the heat sink; The linear diffusion coefficient of the laser chip is not greater than that of the heat sink, and the linear diffusion coefficient of the laser chip is not less than that of the tube tongue. The density of the tube tongue is not less than the density of the laser chip, and the density of the laser chip is not less than the density of the heat sink; and The intrinsic carrier concentration of the laser chip is not less than the intrinsic carrier concentration of the heat sink.

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