400G DR4 optical engine with low cost and high coupling efficiency

Abstract

The utility model relates to a 400G DR4 optical engine with low cost and high coupling efficiency, which is characterized in that a first through hole penetrating through the upper surface and the lower surface of a PCB (printed circuit board) is arranged in a partial area corresponding to a base, a TEC (thermoelectric cooler) fixed with the base and lower than the upper surface of the PCB is arranged in the first through hole, and a second through hole penetrating through the upper surface and the lower surface of the base is arranged in an area surrounded by the first through hole on the base. A heat insulation block with the heat conductivity coefficient lower than that of tungsten copper is fixed in the second through hole, the upper surface of the heat insulation block is flush with the upper surface of the TEC refrigerator, at least one ceramic heat sink is fixed to the upper surface of the TEC refrigerator, an EML chip is fixed to each ceramic heat sink, and an optical fiber array coupled with the EML chips is fixed to the upper surface of the heat insulation block. The method has the beneficial effects that the error of the height of the EML chip and the fiber core in the optical fiber array is small, the coupling efficiency is effectively improved, the yield is greatly improved, the deformation caused by temperature is small, and the optical path is more stable.

Description

Technical Field

[0001] The utility model relates to the technical field of optical engines, and in particular to a low-cost and high-coupling-efficiency 400G DR4 optical engine. Background Art

[0002] Traditional 400G DR4 optical engines generally use TEC coolers to control the temperature of EML chips. The structure of the 400G DR4 optical engine is as follows: Figure 1 , Figure 2 As shown, it includes: a base made of tungsten copper and a PCB board placed on the base, a first through hole penetrating the upper and lower surfaces of the PCB board is provided in a partial area corresponding to the base, a TEC cooler and an optical fiber array fixed to the upper surface of the base are arranged in the first through hole, the TEC cooler is lower than the upper surface of the PCB board, the TEC cooler is bonded to the PCB board with gold wires, a plurality of ceramic heat sinks bonded to the PCB board with gold wires are fixed on the TEC cooler, an EML chip coupled to the optical fiber array is fixed on each ceramic heat sink, a lens and an optical isolator are coupled in sequence between each EML chip and the optical fiber array in the first through hole along the light propagation direction, the lens is fixed to the TEC cooler with ultraviolet glue, and the optical isolator is fixed on the end face of the optical fiber array.

[0003] The TEC cooler used in the 400G DR4 optical engine in this solution consists of a TEC cooling plate and an upper ceramic substrate and a lower ceramic substrate located above and below the TEC cooling plate. The electrodes of the TEC cooler are located on the lower ceramic substrate, which usually has a thickness tolerance of ±75um. The thickness tolerance is generated when the upper ceramic substrate + TEC cooling plate + lower ceramic substrate are welded and fixed. Since the TEC cooler and the optical fiber array are fixed on the same upper surface of the base, the height error between the EML chip and the optical fiber array core is relatively large, which will cause the following defects:

[0004] 1) The error between the EML chip and the fiber array core in the height direction is large, the coupling efficiency decreases, and the yield deteriorates;

[0005] 2) The thickness error of the UV glue under the lens is large, which reduces the reliability of the lens, reduces the coupling efficiency, and deteriorates the yield;

[0006] 3) When working at high temperature, the EML chip and lens are on the cold side of the TEC cooler, while the optical fiber array is on the hot side of the TEC cooler. Specifically, it can be understood that the heat generated by the hot side of the TEC cooler can be conducted to the optical fiber array through the tungsten copper base. Since tungsten copper is a material with high thermal conductivity, the thermal conductivity is usually ~180W / mk, so the temperature difference between the three optical components is too large, and the stability of the optical path is reduced; when working at low temperature, the EML chip and lens are on the hot side of the TEC cooler, while the optical fiber array is on the cold side of the TEC cooler, which also leads to a large temperature difference between the three optical components and a decrease in the stability of the optical path.

[0007] In addition, there is also a solution in the prior art to fix the optical fiber array and the ceramic heat sink on the upper surface of the TEC cooler at the same time. Although this solution does not need to consider the influence of the thickness tolerance of the TEC cooler of ±75um to ensure that the height error between the EML chip and the fiber core in the optical fiber array is small, this solution uses a large-sized TEC cooler, which is relatively expensive. Utility Model Content

[0008] The technical problem to be solved by the utility model is to provide a low-cost and high-coupling-efficiency 400G DR4 optical engine to overcome the deficiencies in the above-mentioned prior art.

[0009] The utility model solves the above technical problems with the following technical solutions: a low-cost, high-coupling-efficiency 400G DR4 optical engine, comprising: a base made of tungsten copper and a PCB board placed on the base, a first through hole penetrating the upper and lower surfaces of the PCB board is provided in a partial area corresponding to the base, a TEC cooler fixed to the base and lower than the upper surface of the PCB board is arranged in the first through hole, a second through hole penetrating the upper and lower surfaces of the base is provided in the area surrounded by the first through hole, a heat insulation block with a lower thermal conductivity than that of tungsten copper is fixed in the second through hole, the upper surface of the heat insulation block is flush with the upper surface of the TEC cooler, at least one ceramic heat sink bonded to the PCB board with gold wire is fixed on the upper surface of the TEC cooler, an EML chip is fixed on each ceramic heat sink, and an optical fiber array coupled to all the EML chips is fixed on the upper surface of the heat insulation block.

[0010] The beneficial effect of the utility model is that the ceramic heat sink with the EML chip and the optical fiber array are placed on the same horizontal plane, and the influence of the thickness tolerance of the TEC cooler of ±75um is not required to be considered, so as to ensure that the height error between the EML chip and the fiber core in the optical fiber array is small, effectively improve the coupling efficiency and greatly improve the yield rate. Since the ceramic heat sink with the EML chip is fixed on the TEC cooler, and the optical fiber array is fixed on the thermal insulation block with a lower thermal conductivity than that of tungsten copper, when working at high and low temperatures, the temperature difference between the EML chip and the optical fiber array is small, the deformation caused by temperature is small, and the optical path is more stable. In addition, the size of the TEC cooler is not changed in this solution, but a thermal insulation block is introduced to solve the corresponding technical problem, so the cost is lower.

[0011] On the basis of the above technical solution, the present invention can also be improved as follows.

[0012] Furthermore, each side of the insulation block is bonded to the base using epoxy structural adhesive.

[0013] The above further beneficial effects are: the epoxy structural adhesive has a low thermal conductivity of only 0.2W / mk to 0.4W / mk, and the thermal insulation block and the base are bonded with the epoxy structural adhesive, which can reduce heat transfer.

[0014] Furthermore, the material of the heat insulation block is quartz.

[0015] Further beneficial effects of the above are: quartz has a low thermal conductivity of only ~1 W / mk, which can effectively insulate to reduce the temperature difference between the EML chip and the optical fiber array, and its thermal expansion coefficient is also low.

[0016] Furthermore, a lens is coupled between each EML chip and the optical fiber array, and the lens is fixed on the upper surface of the TEC cooler.

[0017] Furthermore, the lens is bonded to the TEC cooler by using ultraviolet glue.

[0018] A further beneficial effect of the above method is that the thickness tolerance of the UV glue under the lens can be reduced, and the reliability is higher.

[0019] Furthermore, an optical isolator is coupled between each lens and the optical fiber array, and the optical isolator is fixed on the end face of the optical fiber array. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a top view of a 400G DR4 optical engine in the prior art;

[0021] Figure 2 This is a main view of a 400G DR4 optical engine in the prior art;

[0022] Figure 3 A top view of the low-cost and high-coupling-efficiency 400G DR4 optical engine of the utility model;

[0023] Figure 4 This is the front view of the low-cost and high-coupling-efficiency 400G DR4 optical engine of the utility model.

[0024] In the accompanying drawings, the components represented by the reference numerals are listed as follows:

[0025] 1. Base, 110, second through hole, 2. PCB board, 210, first through hole, 3. TEC cooler, 4. thermal insulation block, 5. ceramic heat sink, 6. EML chip, 7. optical fiber array, 8. lens, 9. optical isolator. DETAILED DESCRIPTION

[0026] The principles and features of the present invention are described below in conjunction with the accompanying drawings. The examples given are only used to explain the present invention and are not used to limit the scope of the present invention.

[0027] Example 1

[0028] like Figure 3 , Figure 4 As shown, a low-cost and high-coupling-efficiency 400G DR4 optical engine comprises: a base 1 and a PCB board 2. The base 1 is made of tungsten copper, which is a material with high thermal conductivity, and the thermal conductivity is generally 180W / mk. The PCB board 2 is placed on the base 1, and a first through hole 210 penetrating the upper and lower surfaces of the PCB board 2 is provided in a partial area corresponding to the base 1; a TEC refrigerator 3 is arranged in the first through hole 210, and the TEC refrigerator 3 is fixed to the base 1, and the upper surface of the TEC refrigerator 3 is lower than the upper surface of the PCB board 2; a second through hole 110 penetrating the upper and lower surfaces of the base 1 is provided in the area surrounded by the first through hole 210, and a heat insulation block 4 with a lower thermal conductivity than that of tungsten copper is fixed in the second through hole 110, that is, the heat insulation block 4 has a lower thermal conductivity than that of the base 1;

[0029] The upper surface of the heat-insulating block 4 is flush with the upper surface of the TEC refrigerator 3. Since the second through hole 110 is provided on the base 1 and the lower end of the heat-insulating block 4 is in the second through hole 110, it can be well ensured that the upper surface of the heat-insulating block 4 is flush with the upper surface of the TEC refrigerator 3. In addition, at least one ceramic heat sink 5 bonded with gold wire to the PCB board 2 is fixed on the upper surface of the TEC refrigerator 3, and each ceramic heat sink 5 is fixed with an EML chip 6. An optical fiber array 7 coupled with all the EML chips 6 is fixed on the upper surface of the heat-insulating block 4. Through this operation, it is not necessary to consider the thickness of the TEC refrigerator 3. The influence of the difference of ±75um is reduced to ensure that the height error of the EML chip 6 and the core of the optical fiber array 7 is small, which effectively improves the coupling efficiency and greatly improves the yield. Since the ceramic heat sink 5 with the EML chip 6 is fixed on the TEC cooler 3, and the optical fiber array 7 is fixed on the insulation block 4 whose thermal conductivity is lower than that of tungsten copper, when working at high and low temperatures, the temperature difference between the EML chip 6 and the optical fiber array 7 is small, the deformation caused by temperature is small, and the optical path is more stable. In addition, the size of the TEC cooler 3 is not changed in this solution, but a thermal insulation block 4 is introduced to solve the corresponding technical problems, so the cost is lower.

[0030] Example 2

[0031] like Figure 3 , Figure 4 As shown, this embodiment is a further improvement on the basis of embodiment 1, and the details are as follows:

[0032] Each side of the insulation block 4 is bonded to the base 1 with epoxy structural adhesive. The thermal conductivity of the epoxy structural adhesive is low, only 0.2W / mk~0.4W / mk. The insulation block 4 and the base 1 are bonded with epoxy structural adhesive to reduce heat transfer. Normally, the four sides of the insulation block 4 are bonded to the base 1 with epoxy structural adhesive.

[0033] Example 3

[0034] like Figure 3 , Figure 4 As shown, this embodiment is a further improvement on the basis of Embodiment 1 or 2, and the details are as follows:

[0035] The insulation block 4 is made of quartz, which has a low thermal conductivity of only 1 W / mk, and can effectively insulate to reduce the temperature difference between the EML chip 6 and the optical fiber array 7. In addition, its thermal expansion coefficient is also low.

[0036] Example 4

[0037] like Figure 3 , Figure 4 As shown, this embodiment is a further improvement on any one of Embodiments 1 to 3, and the details are as follows:

[0038] A lens 8 is coupled between each EML chip 6 and the optical fiber array 7. The lens 8 is fixed on the upper surface of the TEC cooler 3. The lens 8 is bonded to the TEC cooler 3 using UV glue. Since the influence of the thickness tolerance of the TEC cooler 3 of ±75um does not need to be considered in this solution to ensure that the error in the height direction between the EML chip 6 and the core of the optical fiber array 7 is small, the thickness tolerance of the UV glue under the lens 8 is also small, and the reliability is higher.

[0039] In addition, an optical isolator 9 is coupled between each lens 8 and the optical fiber array 7. The optical isolator 9 is fixed on the end face of the optical fiber array 7. The light beam emitted by each EML chip 6 is coupled into the core of the optical fiber array 7 after passing through a lens 8 and an optical isolator 9 in turn.

[0040] Furthermore: four ceramic heat sinks 5 are fixed on the upper surface of the TEC cooler 3 along the width direction of the PCB board 2, and an EML chip 6 is fixed on each ceramic heat sink 5, so the number of lenses 8 is four, the number of optical isolators 9 is four, and the optical fiber array 7 is a four-channel optical fiber array.

[0041] Although the embodiments of the present invention have been shown and described above, it can be understood that the above embodiments are exemplary and cannot be understood as limitations of the present invention. Ordinary technicians in the field can change, modify, replace and modify the above embodiments within the scope of the present invention.

Claims

1. A low-cost and high-coupling-efficiency 400G DR4 optical engine, comprising: A base (1) made of tungsten copper and a PCB (2) placed on the base (1), wherein a first through hole (210) penetrating the upper and lower surfaces of the PCB (2) is provided in a partial area corresponding to the base (1), wherein a TEC cooler (3) fixed to the base (1) and lower than the upper surface of the PCB (2) is arranged in the first through hole (210), and a second through hole (110) penetrating the upper and lower surfaces of the base (1) is provided in the area surrounded by the first through hole (210). A heat insulating block (4) having a lower thermal conductivity than that of tungsten copper is fixed in the second through hole (110); the upper surface of the heat insulating block (4) is flush with the upper surface of the TEC refrigerator (3); at least one ceramic heat sink (5) bonded to the PCB board (2) by a gold wire is fixed on the upper surface of the TEC refrigerator (3); an EML chip (6) is fixed on each ceramic heat sink (5); and an optical fiber array (7) coupled to all the EML chips (6) is fixed on the upper surface of the heat insulating block (4).

2. The low-cost, high-coupling-efficiency 400G DR4 optical engine according to claim 1, characterized in that: Each side surface of the heat insulation block (4) is bonded to the base (1) using epoxy structural adhesive.

3. The low-cost, high-coupling-efficiency 400G DR4 optical engine according to claim 1, characterized in that: The material of the heat insulation block (4) is quartz.

4. A low-cost, high-coupling-efficiency 400G DR4 optical engine according to any one of claims 1 to 3, characterized in that: A lens (8) is coupled between each EML chip (6) and the optical fiber array (7), and the lens (8) is fixed on the upper surface of the TEC cooler (3).

5. The low-cost, high-coupling-efficiency 400G DR4 optical engine according to claim 4, characterized in that: The lens (8) is bonded to the TEC refrigerator (3) using ultraviolet glue.

6. The low-cost, high-coupling-efficiency 400G DR4 optical engine according to claim 4, characterized in that: An optical isolator (9) is coupled between each lens (8) and the optical fiber array (7), and the optical isolator (9) is fixed on the end face of the optical fiber array (7).

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