CN113437637A

CN113437637A - Laser and preparation method thereof

Info

Publication number: CN113437637A
Application number: CN202110696315.4A
Authority: CN
Inventors: 黄雪琴
Original assignee: Zhongke Haoyue Dongguan Semiconductor Technology Co ltd
Current assignee: Zhongke Haoyue Dongguan Semiconductor Technology Co ltd
Priority date: 2021-06-22
Filing date: 2021-06-22
Publication date: 2021-09-24

Abstract

The application relates to a laser and a preparation method thereof, belonging to the technical field of semiconductor laser devices. The laser comprises an insulating substrate, a metal column, a circuit layer and a laser chip. The insulating substrate is provided with a heat conduction through hole penetrating through the insulating substrate. The metal column is arranged in the heat conduction through hole, and the heat conduction efficiency of the metal column is higher than that of the insulating substrate. The circuit layer is arranged on the surface of the insulating substrate, covers the metal column and is provided with a crystal placing area. The laser chip is arranged in the crystal placing area and electrically connected with the circuit layer. Set up the metal post in insulating substrate, and the heat conduction efficiency of metal post is higher than insulating substrate's heat conduction efficiency, can make laser chip's radiating effect better (compare in insulating substrate and dispel the heat, radiating effect is better after adding the metal post) to the heat conduction demand of high power VCSEL device.

Description

Laser and preparation method thereof

Technical Field

The present disclosure relates to semiconductor laser devices, and more particularly, to a laser and a method for fabricating the same.

Background

The semiconductor laser device has the advantages of wide wavelength selection range, small volume, high efficiency and the like, and is one of the most important semiconductor devices, and particularly has wide application in the fields of laser storage, laser display, laser printing, material processing, biomedicine and the like for high-power semiconductor devices.

In the aspect of the structure of the laser, the development prospect and the practical value of a Vertical Cavity Surface Emitting Laser (VCSEL) are higher. The threshold current and output power of the VCSEL device are very sensitive to temperature, and the device dissipates heat during operation, so an aluminum nitride material with a high thermal conductivity is generally selected as a substrate of the VCSEL device.

Disclosure of Invention

At present, the heat conductivity coefficient of the aluminum nitride substrate is 170-200W/m.K, and the heat conduction requirement of a high-power VCSEL device cannot be met.

In view of the deficiencies of the prior art, an object of the embodiments of the present application includes providing a laser and a method for manufacturing the same to improve the problem of poor heat dissipation effect of the laser.

In a first aspect, an embodiment of the present application provides a laser, which includes an insulating substrate, a metal pillar, a circuit layer, and a laser chip. The insulating substrate is provided with a heat conduction through hole penetrating through the insulating substrate. The metal column is arranged in the heat conduction through hole, and the heat conduction efficiency of the metal column is higher than that of the insulating substrate. The circuit layer is arranged on the surface of the insulating substrate, covers the metal column and is provided with a crystal placing area. The laser chip is arranged in the crystal placing area and electrically connected with the circuit layer.

Set up the metal post in insulating substrate, and the heat conduction efficiency of metal post is higher than insulating substrate's heat conduction efficiency, can make laser chip's radiating effect better (compare in insulating substrate and dispel the heat, radiating effect is better after adding the metal post) to the heat conduction demand of high power VCSEL device.

In some embodiments of the present application, the heat conducting through hole includes a plurality of metal posts, and each of the metal posts is disposed in each of the heat conducting through holes. Through the setting of a plurality of metal columns, the radiating effect of the laser chip can be further improved.

In some embodiments of the present application, the plurality of thermal vias are distributed in an array on the insulating substrate, and the outermost thermal vias correspond to edges of the laser chip. All parts of the laser chip can be uniformly cooled.

In some embodiments of the present application, a surface of the insulating substrate facing away from the circuit layer is provided with a heat conducting layer, and the heat conducting layer covers and connects the metal posts. Laser chip produces a large amount of heats in work, and most heats can be conducted through the metal post, and the rethread heat-conducting layer dispels the heat, makes laser chip's radiating effect better.

In some embodiments of the present application, the metal pillar is a gold pillar, a silver pillar, or a copper pillar; the insulating substrate is a ceramic substrate, a glass substrate or a glass fiber board. The substrate has a good heat dissipation effect, and can be matched with metal columns made of gold, silver or copper to achieve a better heat dissipation effect of the laser chip.

In some embodiments of the present application, the insulating substrate is further provided with a first electrode through hole and a second electrode through hole penetrating through the insulating substrate, the first electrode through hole is provided with a first electrode pillar for connecting the first electrode, and the second electrode through hole is provided with a second electrode pillar for connecting the second electrode.

The circuit layer comprises a first circuit layer and a second circuit layer, the first circuit layer is arranged on the surface of the insulating substrate and covers the first electrode column and is conducted with the first electrode column, and the second circuit layer is arranged on the surface of the insulating substrate and covers the second electrode column and is conducted with the second electrode column.

A crystal placing area is arranged on the second circuit layer, the crystal placing area covers the metal column, and a laser chip on the crystal placing area is electrically connected with the second circuit layer; the first circuit layer is electrically connected with the laser chip through a conducting wire.

The first electrode is communicated with the first electrode column, the first electrode column is communicated with the first circuit layer, the first circuit layer is communicated with the laser chip through a conducting wire, the laser chip is communicated with the second circuit layer, the second circuit layer is communicated with the second electrode column, and the second electrode column is communicated with the second electrode, so that current on the laser chip forms a loop, and the laser chip works.

In some embodiments of the present application, the laser chip has a first side and a second side opposite to each other, and the first side and the second side are respectively conducted to the first circuit layer through a plurality of conductive wires.

The inventor researches and discovers that the VCSEL chip structure has great requirements on the uniformity of current injection, and if the current injection is not uniform, the laser wavelength can be shifted. Therefore, in the application, the two sides of the laser chip are communicated with the first circuit layer through the plurality of conductive wires, current can be transmitted through the plurality of conductive wires, and the current is injected from the two sides of the laser chip, so that the current injection of the laser chip is more uniform, and the laser wavelength emitted by the laser chip is more stable; and the requirement on the circuit layer is not high, and the circuit layer is easier to prepare.

In some embodiments of the present disclosure, the laser chip includes a plurality of laser chips, the plurality of laser chips are sequentially arranged, a plurality of groups of sequentially arranged heat conducting through holes are disposed on the insulating substrate, and one group of heat conducting through holes corresponds to one laser chip; the circuit layer further comprises an intermediate circuit layer, the intermediate circuit layer is located between the first circuit layer and the second circuit layer, the intermediate circuit layer further covers the metal columns in the group of heat conduction through holes, the intermediate circuit layer is electrically connected with the laser chips corresponding to the heat conduction through holes, and the intermediate circuit layer is further electrically connected with two sides of the adjacent laser chips through the plurality of conducting wires.

A plurality of laser chips can integrate high-power laser, and the both sides of every laser chip all switch on through many conductor wires and circuit layer, can make the electric current of every laser chip of high-power laser all pour into comparatively evenly, and the electric current on the circuit layer evenly distributed also, can make the circuit distribution of laser more reasonable.

In some embodiments of the present disclosure, the plurality of laser chips are arranged in an array, and two sides of some of the laser chips are respectively connected to the first circuit layer through a plurality of conductive wires; and two sides of the other part of the laser chip are respectively communicated with the middle circuit layer through a plurality of conducting wires.

The space utilization rate of the laser chip integrated high-power laser arranged in an array is higher, and the distribution of each component of the obtained device is more reasonable.

In some embodiments of the present application, the laser chip includes a plurality of laser chips, the plurality of laser chips are sequentially arranged, a plurality of groups of sequentially arranged heat conducting through holes are disposed on the insulating substrate, and one group of heat conducting through holes corresponds to one laser chip. The first side and the second side of each laser chip are respectively communicated with the first circuit layer through a plurality of conducting wires.

In a second aspect, the present application provides a method for manufacturing the above laser, including the following steps: and punching a hole on the insulating substrate to form a heat conduction through hole. And filling the heat conduction through holes with heat conduction metal in an electroplating mode to form metal columns. And forming a circuit layer on the surface of the insulating substrate, wherein the metal column is covered by the circuit layer. And fixing the laser chip in the crystal placing area of the circuit layer and electrically connecting the laser chip with the circuit layer.

The laser prepared by the method has better heat dissipation effect, so that the heat conduction requirement of a high-power VCSEL device is met.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings that are required to be used in the embodiments will be briefly described below, it should be understood that the following drawings only illustrate some embodiments of the present application and therefore should not be considered as limiting the scope, and for those skilled in the art, other related drawings can be obtained from the drawings without inventive effort.

Fig. 1 is a cross-sectional view of a VCSEL device provided in an embodiment of the present application;

fig. 2 is an exploded view of a VCSEL device provided in an embodiment of the present application;

FIG. 3 is a schematic front view of a VCSEL device;

FIG. 4 is a schematic diagram of a backside bonding pad of a VCSEL device;

FIG. 5 is a schematic diagram of a single series VCSEL device configuration;

FIG. 6 is a schematic structural diagram of a single parallel series VCSEL device;

fig. 7 is a schematic structural diagram of a multi-series-parallel VCSEL device.

Icon: 110-an insulating substrate; 120-metal posts; 130-a line layer; 140-laser chip; 111-a first surface; 112-a second surface; 121-thermally conductive layer; 151-positive conductive post; 152-negative conductive post; 153-positive electrode pad; 154-negative electrode pad; 131-a first circuit layer; 132-a second circuit layer; 155-an electrically conductive line; 141-a first side; 142-a second side; 1311-notch; 1321-a bulk structure; 133-intermediate line layer; 160-heat conducting box dam; 170-cover plate.

Detailed Description

The threshold current and the output power of a Vertical Cavity Surface Emitting Laser (VCSEL) are very sensitive to temperature, the threshold current exponentially increases along with the increase of the temperature of an active region, and the electro-optic conversion efficiency exponentially decreases along with the increase of the temperature of the active region; and the lasing wavelength of the VCSEL device is easy to generate a red shift phenomenon along with the increase of the temperature of the active region when the temperature of the active region is increased.

Due to the influence of temperature, stress is generated inside due to the difference of thermal expansion coefficients of materials of all layers, diffusion among all layers is intensified, the device is degraded, and the service life of the VCSEL device is shortened. In order to achieve high operating temperature, low threshold current, high power, etc., each of the influencing factors must be minimized through an optimal design. In order to increase the heat dissipation of the device during operation, an aluminum nitride material with a high thermal conductivity coefficient is generally selected as the substrate, but the heat conduction of the current aluminum nitride substrate is 170-200W/m.K, which cannot meet the heat conduction requirement of the high-power VCSEL device.

Therefore, the present application provides a laser device, which can improve the heat dissipation performance. The laser in this application may be a VCSEL device, or may be another laser, and this application is not limited thereto. The following description will be given taking as an example that the laser is a VCSEL device.

Fig. 1 is a cross-sectional view of a VCSEL device provided in an embodiment of the present application, and fig. 2 is an exploded view of the VCSEL device provided in an embodiment of the present application. Referring to fig. 1 and 2, the VCSEL device includes an insulating substrate 110, a metal pillar 120, a circuit layer 130, and a laser chip 140. The circuit layer 130 is disposed on the insulating substrate 110, the laser chip 140 is disposed on the circuit layer 130, and the metal pillar 120 is disposed in the insulating substrate 110, so that heat generated by the laser chip 140 during operation can be dissipated through the insulating substrate 110 and also through the metal pillar 120, thereby improving heat dissipation performance of the VCSEL device.

In the present application, the insulating substrate 110 may be a ceramic substrate, a glass substrate, or a glass fiber board. The ceramic substrate may be an aluminum nitride substrate or an aluminum oxide substrate.

Referring to fig. 1, the insulating substrate 110 has a first surface 111 and a second surface 112, a thermal via is disposed on the insulating substrate 110, the thermal via penetrates the first surface 111 and the second surface 112 of the insulating substrate 110, and a metal pillar 120 is disposed in the thermal via. The circuit layer 130 is disposed on the surface of the insulating substrate 110, the metal pillar 120 is covered by the circuit layer 130, and a die-placing region is disposed on the circuit layer 130. The laser chip 140 is disposed in the die pad and electrically connected to the circuit layer 130.

In the present application, the heat conduction efficiency of the metal pillar 120 is higher than that of the insulating substrate 110. Compared with the insulating substrate 110 for heat dissipation, the heat dissipation effect is better after the metal posts 120 are added, so that the heat dissipation effect of the laser chip 140 is better, and the heat conduction requirement of the high-power VCSEL device is facilitated.

Optionally, the metal pillar 120 is a gold pillar, a silver pillar, or a copper pillar. The selection of the metal material can be higher than the heat conduction efficiency of the insulating substrate 110, so that the heat dissipation effect of the laser chip 140 is better.

In a possible embodiment, the heat conductive through hole includes a plurality of, and the metal pillar 120 is disposed in each of the heat conductive through holes. The heat dissipation effect of the laser chip 140 can be further improved by the arrangement of the plurality of metal posts 120. The material of the metal posts 120 may be the same or different, and is not limited in this application.

Further, a plurality of heat conducting through holes are distributed in the insulating substrate 110 in an array, and the outermost heat conducting through holes correspond to the edge of the laser chip 140. All parts of the laser chip 140 can be uniformly radiated, and the radiation is more uniform.

In this application, the surface of the insulating substrate 110 away from the circuit layer 130 is provided with a heat conducting layer 121, and the heat conducting layer 121 covers the metal pillar 120. When the laser chip 140 works, a large amount of heat is generated, most of the heat can be conducted through the metal column 120, and then the heat is dissipated through the heat conduction layer 121, so that the heat dissipation effect of the laser chip 140 is better.

Referring to fig. 1 and fig. 2, in the present application, a first electrode through hole and a second electrode through hole are further disposed on the insulating substrate 110, and both the first electrode through hole and the second electrode through hole penetrate through the first surface 111 and the second surface 112 of the insulating substrate 110. A first electrode column is arranged in the first electrode through hole, a second electrode column is arranged in the second electrode through hole, the first electrode column can be conducted with the first electrode, and the second electrode column can be conducted with the second electrode so as to be communicated with an external power supply.

The first electrode column is a positive conductive column, and the second electrode column is a negative conductive column; or the first electrode column is a negative electrode conductive column, and the second electrode column is a positive electrode conductive column, which is not limited in the application. The first electrode pillar is taken as the positive conductive pillar 151, and the second electrode pillar is taken as the negative conductive pillar 152.

The circuit layer 130 includes a first circuit layer 131 and a second circuit layer 132, the first circuit layer 131 is disposed on the surface of the insulating substrate 110 and covers the positive conductive pillar 151 and is electrically connected to the positive conductive pillar 151, and the second circuit layer 132 is disposed on the surface of the insulating substrate 110 and covers the negative conductive pillar 152 and is electrically connected to the negative conductive pillar 152. A chip placement area is arranged on the second circuit layer 132, the chip placement area covers the metal column 120, and the laser chip 140 on the chip placement area is electrically connected with the second circuit layer 132; the first circuit layer 131 is electrically connected to the laser chip 140 through a conductive wire 155.

The positive electrode is connected to the positive conductive column 151, the positive conductive column 151 is connected to the first circuit layer 131, the first circuit layer 131 is connected to the positive electrode of the laser chip 140 through the conductive line 155, the negative electrode of the laser chip 140 is connected to the second circuit layer 132, the second circuit layer 132 is connected to the negative conductive column 152, and the negative conductive column 152 is connected to the negative electrode, so that the current on the laser chip 140 forms a loop, and the laser chip 140 works.

Optionally, the surface of the insulating substrate 110 facing away from the circuit layer 130 is provided with a positive electrode pad 153 and a negative electrode pad 154, where the positive electrode pad 153 covers the positive electrode conductive pillar 151, and the negative electrode pad 154 covers the negative electrode conductive pillar 152. The electrodes are connected through the positive electrode pad 153 and the negative electrode pad 154 so as to energize the laser chip 140.

The positive conductive pillar 151 and the negative conductive pillar 152 may be made of the same material as the metal pillar 120, or may be different from the metal pillar 120, as long as they are conductive. The conductive wire 155 may be a gold wire, a silver wire, or a copper wire, and may be a gold wire, which has a high melting point, a good conductive effect, and a long service life.

Referring to fig. 1 to fig. 4, the laser chip 140 has a first side 141 and a second side 142 opposite to each other, and the first side 141 and the second side 142 are respectively connected to the first circuit layer 131 through a plurality of conductive wires 155. The inventor researches and discovers that the VCSEL chip structure has great requirements on the uniformity of current injection, and if the current injection is not uniform, the laser wavelength can be shifted. Therefore, in the present application, both sides of the laser chip 140 are connected to the first circuit layer 131 through the plurality of conductive wires 155, and the current can be transmitted through the plurality of conductive wires 155, and the current is injected from both sides of the laser chip 140, so that the current injection of the laser chip 140 is more uniform, and the laser wavelength emitted by the laser chip 140 is more stable; and the requirement on the circuit layer 130 is not high, and the circuit layer 130 is easier to prepare.

With reference to fig. 3 and fig. 4, in an embodiment, one of the laser chips 140 may have a U-shaped projection of the first circuit layer 131, the first circuit layer 131 is disposed on the first surface 111 of the insulating substrate 110, and a notch 1311 facing the negative conductive pillar 152, which is not covered by the insulating substrate 110, is formed on the first circuit layer 131; the projection of the second circuit layer 132 is a block structure 1321, part of the second circuit layer 132 of the block structure 1321 extends into the notch 1311, the second circuit layer 132 extending into the notch 1311 covers the metal pillar 120, the first circuit layer 131 and the second circuit layer 132 are not in direct contact, a chip placement area is arranged on the second circuit layer 132, the laser chip 140 is arranged on the chip placement area, and the first side 141 and the second side 142 of the laser chip 140 are respectively conducted with two sides of the first circuit layer 131 of the U-shaped structure through a plurality of conductive wires 155.

The first side 141 and the second side 142 of the laser chip 140 can both inject current, which can make the current more uniformly injected into the laser chip 140, so that the laser wavelength emitted by the laser chip 140 is more stable. And part of the heat generated by the laser chip 140 during operation can be directly dissipated through the metal pillar 120.

Optionally, there may be a plurality of positive conductive pillars 151 and a plurality of negative conductive pillars 152, the positive conductive pillars 151 may be disposed side by side and all conducted with the positive bonding pad 153, and the negative conductive pillars 152 are also disposed side by side and all conducted with the negative bonding pad 154, so as to connect the positive electrode and the negative electrode. The middle portion of the first circuit layer 131 projected as a U-shaped structure covers the plurality of positive conductive pillars 151, and one end of the second circuit layer 132 projected as a block structure 1321 far away from the first circuit layer 131 covers the plurality of negative conductive pillars 152, so that the current passing through the plurality of positive conductive pillars 151 and the negative conductive pillars 152 can be uniformly distributed on the circuit layer 130, and the subsequent current can be more uniformly injected into the laser chip 140.

Fig. 5 is a schematic structural diagram of a single series VCSEL device. Referring to fig. 5, the plurality of laser chips 140 are sequentially arranged, the laser chips 140 are sequentially arranged along the direction from the positive conductive post 151 to the negative conductive post 152, and the insulating substrate 110 is provided with a plurality of groups of sequentially arranged heat conducting through holes, one group of heat conducting through holes corresponding to one laser chip 140; the circuit layer 130 further includes an intermediate circuit layer 133, the intermediate circuit layer 133 is located between the first circuit layer 131 and the second circuit layer 132, the intermediate circuit layer 133 further covers the metal posts 120 in the group of heat conducting through holes, the intermediate circuit layer 133 is electrically connected to the laser chips 140 corresponding to the heat conducting through holes, and the intermediate circuit layer 133 is further electrically connected to two sides of the adjacent laser chips 140 through a plurality of conductive wires 155.

The plurality of laser chips 140 can integrate a high-power laser, and both sides of each laser chip 140 are communicated with the circuit layer 130 through the plurality of conductive wires 155, so that the current of each laser chip 140 of the high-power laser can be injected more uniformly, and the current on the circuit layer 130 is also uniformly distributed, so that the circuit distribution of the laser is more reasonable.

With continued reference to fig. 5, the number of intermediate circuit layers 133 is one less than the number of laser chips 140, for example: if the VCSEL device includes two laser chips 140, one intermediate circuit layer 133 may be disposed (see fig. 5-a, fig. 5-a is a schematic front circuit diagram of the VCSEL device in which two laser chips 140 are connected in series), one heat conduction layer 121 may be disposed (see fig. 5-b, fig. 5-b is a schematic back pad diagram of the VCSEL device in which two laser chips 140 are connected in series), or two heat conduction layers may be disposed, which is not limited in the present application; if the VCSEL device includes three laser chips 140, two intermediate circuit layers 133 may be disposed (see fig. 5-c, which is a schematic diagram of a front circuit of the VCSEL device with three laser chips 140 connected in series), two heat conducting layers 121 may be disposed (see fig. 5-d, which is a schematic diagram of a back bonding pad of the VCSEL device with three laser chips 140 connected in series), or one or three layers may be disposed, which is not limited in this application; if the VCSEL device includes four laser chips 140, three intermediate circuit layers 133 may be disposed (see fig. 5-e, fig. 5-e are schematic front circuit diagrams of the VCSEL device with four laser chips 140 connected in series), two heat conduction layers 121 may be disposed (see fig. 5-f, fig. 5-f are schematic back circuit diagrams of the VCSEL device with four laser chips 140 connected in series), or one, three, or four layers may be disposed, which is not limited in this application.

With continued reference to fig. 5-a, the projection of the middle circuit layer 133 is a Y-shaped structure, which is formed by combining a partial circuit layer with a block-shaped projection and a partial circuit layer with a U-shaped projection. Wherein, the part of the circuit layer with block projection extends into the notch 1311 of the first circuit layer 131 with U-shaped projection and covers the metal pillar 120, the part of the circuit layer with U-shaped projection forms a new notch 1311 facing the negative conductive pillar 152, and part of the second circuit layer extends into the notch 1311; the first circuit layer 131, the intermediate circuit layer 133 and the second circuit layer 132 are not in direct contact, the second circuit layer 132 and the intermediate circuit layer 133 are both provided with a crystal placing region, one crystal placing region is provided with one laser chip 140 (two laser chips 140 in total), and a first side 141 and a second side 142 of the first laser chip 140 are respectively conducted with two sides of the first circuit layer 131 projected to be in a U-shaped structure through a plurality of conducting wires 155; the first side 141 and the second side 142 of the second laser chip 140 are respectively conducted to two sides of the U-shaped projection of the middle circuit layer 133 through a plurality of conductive wires 155.

Fig. 6 is a schematic structural diagram of a single series VCSEL device. Referring to fig. 6, the plurality of laser chips 140 are sequentially arranged, the laser chips 140 are sequentially arranged along a direction perpendicular to the anode conductive pillars 151 to the cathode conductive pillars 152, and the insulating substrate 110 is provided with a plurality of groups of sequentially arranged heat conducting through holes, one group of heat conducting through holes corresponding to one laser chip 140; the first side 141 and the second side 142 of each laser chip 140 are electrically connected to the first circuit layer 131 through a plurality of conductive wires 155, respectively.

With reference to fig. 6, the projection of the first circuit layer 131 forms a plurality of gaps 1311, the projection of the second circuit layer 132 includes a plurality of block structures 1321, one gap 1311 corresponds to one block structure 1321, and one laser chip 140 is mounted in one gap 1311. For example: if the VCSEL device includes two laser chips 140, the projection of the first circuit layer 131 forms two notches 1311 facing the negative conductive pillar 152, the projection of the second circuit layer 132 includes two block structures 1321 extending toward the positive conductive pillar 151 (see fig. 6-a, where fig. 6-a is a schematic front circuit diagram of the VCSEL device with two laser chips 140 connected in parallel), one block structure 1321 extends into one notch 1311 and covers part of the metal pillar 120, and one heat conduction layer 121 may be provided (see fig. 6-b, where fig. 6-b is a schematic back bonding pad diagram of the VCSEL device with two laser chips 140 connected in parallel), or two heat conduction layers may be provided, which is not limited in this application. Two block structures 1321 of the second circuit layer 132 are respectively provided with a chip placement region, one chip placement region is provided with one laser chip 140 (two laser chips 140 in total), and the first side 141 and the second side 142 of the first laser chip 140 are respectively conducted with two sides of the edge of the first notch 1311 of the first circuit layer 131 through a plurality of conductive wires 155; the first side 141 and the second side 142 of the other laser chip 140 are respectively connected to two sides of the edge of the second notch 1311 of the first circuit layer 131 through a plurality of conductive wires 155.

If the VCSEL device includes three laser chips 140, the projection of the first circuit layer 131 forms three notches 1311 facing the negative conductive pillars 152, the projection of the second circuit layer 132 includes three block structures 1321 extending toward the positive conductive pillars 151 (see fig. 6-c, where fig. 6-c is a schematic front circuit diagram of the VCSEL device with three laser chips 140 connected in parallel), one block structure 1321 extends into one notch 1311 and covers part of the metal pillar 120, and one heat conduction layer 121 may be provided (see fig. 6-d, where fig. 6-d is a schematic back bonding pad diagram of the VCSEL device with three laser chips 140 connected in parallel), or two or three heat conduction layers may be provided, which is not limited in this application. A crystal placing region is respectively arranged on the three block structures 1321 of the second circuit layer 132, a laser chip 140 (three laser chips 140 in total) is arranged on one crystal placing region, and the first side 141 and the second side 142 of the first laser chip 140 are respectively conducted with two sides of the edge of the first notch 1311 of the first circuit layer 131 through a plurality of conductive wires 155; the first side 141 and the second side 142 of the second laser chip 140 are respectively connected to two sides of the edge of the second notch 1311 of the first circuit layer 131 through a plurality of conductive wires 155; the first side 141 and the second side 142 of the third laser chip 140 are respectively connected to two sides of the edge of the third notch 1311 of the first circuit layer 131 through a plurality of conductive wires 155.

Fig. 7 is a schematic structural diagram of a multi-series-parallel VCSEL device. The plurality of laser chips 140 are arranged in an array, and two sides of a part of the laser chips 140 are respectively communicated with the first circuit layer 131 through a plurality of conductive wires 155; two sides of the other part of the laser chip 140 are respectively conducted with the middle circuit layer 133 through a plurality of conductive wires 155. The space utilization rate of the high-power laser integrated by the laser chips 140 arranged in an array is higher, and the distribution of each component of the obtained device is more reasonable.

With reference to fig. 7, the number of the middle circuit layers 133 is one less than the number of the rows of the laser chips 140 (the direction from the positive conductive pillars 151 to the negative conductive pillars 152 is taken as a row), for example: if the VCSEL device includes four laser chips 140 (two rows of laser chips 140, two columns of laser chips 140), an intermediate circuit layer 133 may be disposed (see fig. 7-a, which is a schematic front circuit diagram of the VCSEL device with four laser chips 140 in two rows and two parallel rows); two notches 1311 are formed in the projection of the first circuit layer 131, two block-shaped portions are formed on one side of the projection of the intermediate circuit layer 133 close to the first circuit layer 131, two U-shaped portions (having two notches 1311) are formed on one side of the projection of the intermediate circuit layer 133 close to the second circuit layer 132, the projection of the second circuit layer 132 includes two block-shaped structures 1321 extending toward the positive conductive pillar 151, the two block-shaped portions of the intermediate circuit layer 133 extend into the two notches 1311 of the first circuit layer 131, the two block-shaped structures 1321 of the second circuit layer 132 extend into the two notches 1311 of the intermediate circuit layer 133, one heat conducting layer 121 may be provided (see fig. 7-b, which is a schematic diagram of a back pad of a VCSEL device with two serial and two parallel laser chips 140), and two, three or four heat conducting layers may also be provided, which is not limited in this application. Both sides of each laser chip 140 in the first row of laser chips 140 are conducted with the first circuit layer 131 through a plurality of conductive wires 155; both sides of each laser chip 140 in the second row of laser chips 140 are electrically connected to the intermediate circuit layer 133 through a plurality of conductive wires 155.

Please continue to refer to fig. 7, for example: if the VCSEL device includes nine laser chips 140 (three rows of laser chips 140 and three rows of laser chips 140), two intermediate circuit layers 133 may be disposed (see fig. 7-c, which is a schematic front circuit diagram of the VCSEL device with three rows and three parallel rows of nine laser chips 140); wherein the projection of the first circuit layer 131 forms three notches 1311, the middle circuit layer 133 has two, the projection of one middle circuit layer 133 forms three block-shaped portions at a side close to the first circuit layer 131, the projection of one middle circuit layer 133 forms three U-shaped portions (with three notches 1311) at a side close to the second circuit layer 132, the projection of the second circuit layer 132 includes three block-shaped structures 1321 extending toward the positive conductive pillar 151, the three block-shaped portions of the first middle circuit layer 133 extend into the three notches 1311 of the first circuit layer 131, the three block-shaped portions of the adjacent second middle circuit layer 133 extend into the three notches 1311 of the first middle circuit layer 133, the three block-shaped structures 1321 of the second circuit layer 132 extend into the three notches 1 of the second middle circuit layer 133, and the heat conduction layer 121 can be provided with two block-shaped structures 1311 (see fig. 7-d, which is a schematic diagram of back pads of a VCSEL device with three serial-three laser chips 140), two, three or four may also be provided, without limitation in this application. Both sides of each laser chip 140 in the first row of laser chips 140 are conducted with the first circuit layer 131 through a plurality of conductive wires 155; both sides of each laser chip 140 in the second row of laser chips 140 are conducted with the first row of middle line layer 133 through a plurality of conductive wires 155; both sides of each laser chip 140 in the third row of laser chips 140 are electrically connected to the second row of middle circuit layer 133 through a plurality of conductive wires 155.

By the wiring mode, the current characteristic of the VCSEL device composite chip can be realized, so that a high-power VCSEL device can be integrated.

Referring to fig. 1 and fig. 2, in the present application, a heat conducting dam 160 is further disposed on an edge of the first surface 111 of the insulating substrate 110, the heat conducting dam 160 is a metal ring structure, the heat conducting dam 160 and the insulating substrate 110 cooperate to form a groove, the circuit layer 130 and the laser chip 140 are disposed in the groove, and a cover plate 170 covers an upper portion of the heat conducting dam 160 to encapsulate the laser chip 140 to form a VCSEL device.

The preparation method of the VCSEL device comprises the following steps:

(1) and a thermal via is formed by punching a hole in the insulating substrate 110. Besides the heat conducting through holes, the first electrode through holes and the second electrode through holes can be formed together.

(2) And filling the heat-conducting through holes with the heat-conducting metal by electroplating to form the metal posts 120. Optionally, the materials of the positive conductive pillar 151 and the negative conductive pillar 152 are the same as those of the metal pillar 120, so that the heat conductive metal can also fill the first electrode through hole by electroplating to form the positive conductive pillar 151, and the heat conductive metal can fill the second electrode through hole to form the negative conductive pillar 152.

(3) And forming a positive electrode pad 153, a heat conduction layer 121 and a negative electrode pad 154 on the second surface 112 (the surface deviating from the circuit layer 130) of the insulating substrate 110 in an electroplating manner, wherein the positive electrode pad 153, the heat conduction layer 121 and the negative electrode pad 154 are not in direct contact, the positive electrode pad 153 covers the positive electrode conductive column 151, the heat conduction layer 121 covers the metal column 120, and the negative electrode pad 154 covers the negative electrode conductive column 152.

(4) And forming a circuit layer 130 on the surface of the insulating substrate 110, such that the circuit layer 130 covers the metal pillar 120. Optionally, a first circuit layer 131 and a second circuit layer 132 are respectively formed on the first surface 111 (surface facing away from the pad) of the insulating substrate 110 by electroplating, the first circuit layer 131 covers the positive conductive pillar 151 and is electrically connected to the positive conductive pillar 151, and the second circuit layer 132 covers the metal pillar 120 and the negative conductive pillar 152 and is electrically connected to the negative conductive pillar 152. The intermediate circuit layer 133 may be optionally disposed according to requirements, and the corresponding shape of the circuit layer 130 may be disposed according to the arrangement of the plurality of laser chips 140.

(5) The heat conducting dam 160 is disposed at the edge of the first surface 111 of the insulating substrate 110 by electroplating, the heat conducting dam 160 does not contact with the circuit layer 130, and the height of the heat conducting dam 160 can be adjusted according to the height of the laser chip 140, which is not limited in the present application.

(6) The laser chip 140 is fixed on the die-placing area of the circuit layer 130 and electrically connected to the circuit layer 130. The laser chip 140 is fixed on the die-placing area of the circuit layer 130 by die bonding.

(7) Both ends of the conductive line 155 are connected to and electrically connected to the laser chip 140 and the line layer 130, respectively. Optionally, one end of each of the conductive wires 155 is connected to both sides of the laser chip 140, and the other end is connected to the circuit layer 130 by ultrasonic bonding, so that the laser chip 140 is electrically connected to the circuit layer 130.

(8) The edge of the cover plate 170 is covered on the heat conducting dam 160 to encapsulate the laser chip 140, forming a VCSEL device.

The VCSEL device provided by the embodiment of the application has the beneficial effects that:

(1) the metal posts 120 are arranged on the insulating substrate 110, so that part of heat generated by the laser chip 140 during operation can be dissipated through the metal posts 120, the heat dissipation effect of the VCSEL device can be better, the light emitting wavelength of the laser chip 140 can be ensured, and the service life of the laser chip 140 can be prolonged.

(2) The two sides of each laser chip 140 are respectively provided with a plurality of conducting wires 155 for injecting current, so that the current injection is more uniform, the accessible current is increased, and the reliability and the stability of the high-power VCSEL device are improved.

The embodiments described above are some, but not all embodiments of the present application. The detailed description of the embodiments of the present application is not intended to limit the scope of the claimed application, but is merely representative of selected embodiments of the application. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present application.

Claims

1. A laser, comprising:

the heat conduction structure comprises an insulating substrate, wherein a heat conduction through hole penetrating through the insulating substrate is formed in the insulating substrate;

the metal columns are arranged in the heat conduction through holes, and the heat conduction efficiency of the metal columns is higher than that of the insulating substrate;

the circuit layer is arranged on the surface of the insulating substrate, covers the metal column and is provided with a crystal placing area;

and the laser chip is arranged in the crystal placing area and is electrically connected with the circuit layer.

2. The laser of claim 1, wherein the thermally conductive via comprises a plurality and the metal post comprises a plurality, the metal post being disposed within each thermally conductive via.

3. The laser device as claimed in claim 2, wherein the plurality of thermal vias are distributed in the insulating substrate in an array, and the outermost thermal vias correspond to edges of the laser chip.

4. The laser according to any one of claims 1 to 3, wherein a surface of the insulating substrate facing away from the wiring layer is provided with a heat conductive layer, and the heat conductive layer covers the metal post;

or/and the metal column is a gold column, a silver column or a copper column; the insulating substrate is a ceramic substrate, a glass substrate or a glass fiber board.

5. The laser according to any one of claims 1 to 3, wherein the insulating substrate is further provided with a first electrode through hole and a second electrode through hole penetrating through the insulating substrate, the first electrode through hole is provided with a first electrode column for connecting with a first electrode, and the second electrode through hole is provided with a second electrode column for connecting with a second electrode;

the circuit layer comprises a first circuit layer and a second circuit layer, the first circuit layer is arranged on the surface of the insulating substrate, covers the first electrode column and is communicated with the first electrode column, and the second circuit layer is arranged on the surface of the insulating substrate, covers the second electrode column and is communicated with the second electrode column;

the second circuit layer is provided with the crystal placement area, the crystal placement area covers the metal column, and the laser chip on the crystal placement area is electrically connected with the second circuit layer; the first circuit layer is electrically connected with the laser chip through a conducting wire.

6. The laser of claim 5, wherein the laser chip has opposite first and second sides, and wherein the first and second sides are respectively in conductive communication with the first circuit layer through a plurality of conductive wires.

7. The laser device according to claim 6, wherein the laser chip comprises a plurality of laser chips, the plurality of laser chips are sequentially arranged, a plurality of groups of sequentially arranged heat conducting through holes are arranged on the insulating substrate, and one group of heat conducting through holes corresponds to one laser chip; the circuit layer further comprises an intermediate circuit layer, the intermediate circuit layer is located between the first circuit layer and the second circuit layer, the intermediate circuit layer further covers a group of metal columns in the heat conduction through holes, the intermediate circuit layer corresponds to the heat conduction through holes and is electrically connected with the laser chips, and the intermediate circuit layer is further electrically connected with two sides of the laser chips through a plurality of conductive wires.

8. The laser device according to claim 7, wherein a plurality of the laser chips are arranged in an array, and both sides of a part of the laser chips are respectively conducted with the first circuit layer through a plurality of conductive wires; and two sides of the other part of the laser chip are respectively communicated with the middle circuit layer through a plurality of conducting wires.

9. The laser device according to claim 6, wherein the laser chip comprises a plurality of laser chips, the plurality of laser chips are sequentially arranged, a plurality of groups of sequentially arranged heat conducting through holes are arranged on the insulating substrate, and one group of heat conducting through holes corresponds to one laser chip;

the first side and the second side of each laser chip are respectively communicated with the first circuit layer through a plurality of conducting wires.

10. A method of manufacturing a laser according to any of claims 1 to 9, comprising the steps of:

punching the insulating substrate to form the heat conducting through hole;

filling the heat-conducting through hole with heat-conducting metal in an electroplating mode to form the metal column;

forming the circuit layer on the surface of the insulating substrate, so that the circuit layer covers the metal column;

and fixing the laser chip in the crystal placing area of the circuit layer and electrically connecting the laser chip with the circuit layer.