Low-cost 400G DR4 optical engine

Abstract

The utility model relates to a low-cost 400G DR4 optical engine, which comprises a PCB (printed circuit board) fixed on a base, a TEC (thermoelectric cooler) lower than the upper surface of the PCB and arranged in a through hole on the PCB, a ceramic heat sink fixed on the upper surface of an upper ceramic substrate in the TEC, an EML (electro-magnetic logic) chip fixed on the ceramic heat sink, and a DR4 chip fixed on the EML chip. The same end of an upper ceramic substrate and the same end of a lower ceramic substrate in the TEC refrigerator horizontally extend outwards for a certain distance in the light propagation direction, a gap is formed between the sections, extending outwards, of the upper ceramic substrate and the lower ceramic substrate, and a heat insulation plate used for supporting the upper ceramic substrate is arranged in the gap. And an optical fiber array coupled with the EML chip is fixed on the section, extending outwards, of the upper surface of the upper ceramic substrate. The TEC refrigerator has the beneficial effects that the coupling efficiency can be effectively improved, the yield can be greatly improved, and compared with a TEC refrigerator with the larger size and the increased number of TEC refrigeration chips, the cost can be effectively reduced, and meanwhile, the power consumption is kept unchanged.

Description

Technical Field

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

[0002] Traditional 400G DR4 optical engines generally use TEC coolers to control the temperature of the EML chip. The structure of the 400G DR4 optical engine is as follows: Figure 1 , 2 As shown, it includes: a base made of tungsten copper and a PCB board placed on the base, a through hole penetrating the upper and lower surfaces of the PCB board is provided in a part of the 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 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 along the light propagation direction, the lens is fixed to the TEC cooler with ultraviolet glue, and the optical isolator is fixed on the optical port side of the optical fiber array.

[0003] The TEC cooler used in the 400G DR4 optical engine in this solution includes: an upper ceramic substrate, a TEC cooling chip and a lower ceramic substrate, which are arranged from top to bottom. The TEC cooling chip is welded to the upper ceramic substrate, and the TEC cooling chip is also welded to the lower ceramic substrate. The electrode of the TEC cooler is 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 chip + lower ceramic substrate are welded and fixed, which will cause the following defects:

[0004] 1) Since the TEC cooler and the optical fiber array are fixed on the same upper surface of the base, and a ceramic heat sink is fixed on the upper surface of the upper ceramic substrate in the TEC cooler, and the EML chip is fixed on the ceramic heat sink, the height error between the EML chip and the core of the optical fiber array is relatively large, the coupling efficiency is reduced, and the yield is deteriorated;

[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. Utility Model Content

[0007] The technical problem to be solved by the utility model is to provide a low-cost 400G DR4 optical engine to overcome the deficiencies in the above-mentioned prior art.

[0008] The utility model provides a technical solution to the above technical problems as follows: a low-cost 400G DR4 optical engine, comprising: a base and a PCB board placed on the base, a 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 lower than the upper surface of the PCB board is arranged in the through hole, a ceramic heat sink bonded to the PCB board with gold wires is fixed on the upper surface of the upper ceramic substrate in the TEC cooler, an EML chip is fixed on the ceramic heat sink, the same end of the upper ceramic substrate and the lower ceramic substrate in the TEC cooler are horizontally extended outward for a distance in the direction of light propagation, a gap is formed between the outwardly extending sections of the upper ceramic substrate and the lower ceramic substrate, a heat insulation board for supporting the upper ceramic substrate is arranged in the gap, and an optical fiber array coupled to the EML chip is fixed on the outwardly extending section of the upper surface of the upper ceramic substrate.

[0009] The beneficial effects of the utility model are:

[0010] 1) By increasing the size of the upper ceramic substrate and the lower ceramic substrate, the ceramic heat sink and the optical fiber array can be fixed on the upper surface of the upper ceramic substrate in the TEC cooler at the same time, that is, the ceramic heat sink and the optical fiber array are placed on the same height mounting surface, so there is no need to consider the influence of the thickness tolerance of the TEC cooler, ensuring that the error in the height direction between the EML chip on the ceramic heat sink and the optical fiber array core is small, effectively improving the coupling efficiency and greatly improving the yield;

[0011] 2) The TEC cooler only increases the size of the upper ceramic substrate and the lower ceramic substrate, but does not increase the number of TEC cooling chips. Therefore, compared with a TEC cooler with a larger size and an increased number of TEC cooling chips, the cost can be effectively reduced while ensuring the structural stability of the TEC cooler, while the power consumption remains unchanged;

[0012] 3) Since the ceramic heat sink and the optical fiber array are both fixed on the upper ceramic substrate in the TEC cooler, when the low-cost 400G DR4 optical engine is working at high temperature, the EML chip and the optical fiber array are both on the cold side of the TEC cooler, the temperature difference between them is small, the deformation caused by temperature is small, and the optical path is more stable. When the low-cost 400G DR4 optical engine is working at low temperature, the EML chip and the optical fiber array are both on the hot side of the TEC cooler, the temperature difference between them is also small, the deformation caused by temperature is also small, and the optical path is more stable.

[0013] On the basis of the above technical solution, the present invention can also be improved as follows.

[0014] Furthermore, the heat insulation board and the upper ceramic substrate are bonded together by using epoxy structural adhesive, and the heat insulation board and the lower ceramic substrate are bonded together by using epoxy structural adhesive.

[0015] The further beneficial effect of adopting the above method is that the thermal conductivity of the epoxy structural adhesive is very low, only 0.2W / mk to 0.4W / mk, which can reduce heat conduction.

[0016] Furthermore, the material of the heat insulation board is quartz.

[0017] The above further beneficial effects are: the thermal conductivity of quartz is very low, only ~1W / mk, which can be used as a heat shield and effectively ensure the stability of the TEC cooler structure.

[0018] Furthermore, a lens and an optical isolator are coupled in sequence between each EML chip and the optical fiber array along the light propagation direction. The lens is fixed to the upper ceramic substrate by ultraviolet glue, and the optical isolator is fixed on the optical port side of the optical fiber array.

[0019] The further beneficial effects of adopting the above are:

[0020] Since the influence of the thickness tolerance of the TEC cooler does not need to be considered in this solution, the thickness tolerance of the UV glue under the lens is small, the reliability is higher, and the coupling efficiency and yield are improved;

[0021] Since the ceramic heat sink, fiber array and lens are all fixed on the upper ceramic substrate in the TEC cooler, when the low-cost 400G DR4 optical engine is working at high temperature, the ceramic heat sink, fiber array and lens are all on the cold side of the TEC cooler, the temperature difference between them is small, the deformation caused by temperature is small, and the optical path is more stable. When the low-cost 400G DR4 optical engine is working at low temperature, the ceramic heat sink, fiber array and lens are all on the hot side of the TEC cooler, the temperature difference between them is small, the deformation caused by temperature is also small, and the optical path is more stable.

[0022] Furthermore, four ceramic heat sinks are fixed on the upper surface of the upper ceramic substrate along the width direction of the PCB board, and an EML chip coupled to the optical fiber array is fixed on each ceramic heat sink. The number of lenses is four, the number of optical isolators is four, and the optical fiber array is a four-channel optical fiber array. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a top view of a 400G DR4 optical engine in the prior art;

[0024] Figure 2 This is a main view of a 400G DR4 optical engine in the prior art;

[0025] Figure 3 A top view of the low-cost 400G DR4 optical engine of the utility model;

[0026] Figure 4 This is a front view of the low-cost 400G DR4 optical engine of the utility model.

[0027] In the accompanying drawings, the components represented by the reference numerals are listed as follows:

[0028] 1. Base, 2. PCB board, 210, through hole, 3. TEC cooler, 310, upper ceramic substrate, 320, lower ceramic substrate, 330, TEC cooling chip, 4. Ceramic heat sink, 5. Optical fiber array, 6. EML chip, 7. Lens, 8. Optical isolator, 9. Thermal insulation board, 10. Epoxy structural adhesive. DETAILED DESCRIPTION

[0029] 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.

[0030] Example 1

[0031] like Figure 3 , Figure 4 As shown, a low-cost 400G DR4 optical engine includes: a base 1, the base 1 is made of tungsten copper, a PCB board 2 is fixed on the base 1, and a through hole 210 is opened on the PCB board 2 in a part of the area corresponding to the base 1 and passes through the upper and lower surfaces thereof, a TEC cooler 3 is arranged in the through hole 210 and is lower than the upper surface of the PCB board 2, and the TEC cooler 3 includes: an upper ceramic substrate 310, a TEC cooling chip 330 and a lower ceramic substrate 320 which are sequentially distributed from top to bottom, the TEC cooling chip 330 is welded to the upper ceramic substrate 310, and the TEC cooling chip 330 is also welded to the lower ceramic substrate 320;

[0032] A ceramic heat sink 4 bonded with gold wire to the PCB board 2 is fixed on the upper surface of the upper ceramic substrate 310 in the TEC cooler 3, and an EML chip 6 is fixed on the ceramic heat sink 4. One end of the upper ceramic substrate 310 in the TEC cooler 3 horizontally extends outwards for a distance in the direction of light propagation, and one end of the lower ceramic substrate 320 in the TEC cooler 3 horizontally extends outwards for a distance in the direction of light propagation. The upper ceramic substrate 310 and the lower ceramic substrate 320 extend outwards from the same end. After the upper ceramic substrate 310 and the lower ceramic substrate 320 extend outwards for a distance, since there is no TEC cooling chip 330 in the area, a gap is formed between the sections extending outwards of the upper ceramic substrate 310 and the lower ceramic substrate 320. A heat insulation board 9 for supporting the upper ceramic substrate 310 is arranged in the gap. An optical fiber array 5 coupled with the EML chip 6 is fixed on the upper surface of the upper ceramic substrate 310 in the section extending outwards.

[0033] By increasing the size of the upper ceramic substrate 310 and the lower ceramic substrate 320, the ceramic heat sink 4 and the optical fiber array 5 can be fixed on the upper surface of the upper ceramic substrate 310 in the TEC cooler 3 at the same time, that is, the ceramic heat sink 4 and the optical fiber array 5 are placed on the same height mounting surface, so the influence of the thickness tolerance of the TEC cooler 3 does not need to be considered, ensuring that the error in the height direction between the EML chip 6 on the ceramic heat sink 4 and the core of the optical fiber array 5 is small, effectively improving the coupling efficiency and greatly improving the yield;

[0034] The TEC cooler 3 only increases the size of the upper ceramic substrate 310 and the lower ceramic substrate 320, but does not increase the number of the TEC cooling chips 330. Therefore, compared with the TEC cooler 3 with a larger size and an increased number of the TEC cooling chips 330, the cost can be effectively reduced while ensuring the structural stability of the TEC cooler 3, while the power consumption remains unchanged;

[0035] Since the ceramic heat sink 4 and the optical fiber array 5 are both fixed on the upper ceramic substrate 310 in the TEC cooler 3, when the low-cost 400G DR4 optical engine is working at high temperature, the EML chip 6 and the optical fiber array 5 are both on the cold side of the TEC cooler 3, the temperature difference between them is small, the deformation caused by temperature is small, and the optical path is more stable. When the low-cost 400G DR4 optical engine is working at low temperature, the EML chip 6 and the optical fiber array 5 are both on the hot side of the TEC cooler 3, the temperature difference between them is also small, the deformation caused by temperature is also small, and the optical path is more stable.

[0036] Example 2

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

[0038] The heat insulation board 9 is bonded to the upper ceramic substrate 310 with epoxy structural adhesive 10, and the heat insulation board 9 is bonded to the lower ceramic substrate 320 with epoxy structural adhesive 10. The thermal conductivity of epoxy structural adhesive 10 is very low, only 0.2W / mk to 0.4W / mk, which can reduce heat conduction.

[0039] Furthermore, the heat insulation board 9 is made of quartz, which has a very low thermal conductivity of only 1 W / mk, and can be well used as a heat insulation board and effectively ensure the stability of the structure of the TEC refrigerator 3 .

[0040] Example 3

[0041] 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:

[0042] A lens 7 and an optical isolator 8 are coupled in sequence between each EML chip 6 and the optical fiber array 5 along the light propagation direction. The lens 7 is fixed to the upper ceramic substrate 310 by using UV glue, and the optical isolator 8 is fixed to the optical port side of the optical fiber array 5. Since the influence of the thickness tolerance of the TEC cooler 3 does not need to be considered in this solution, the thickness tolerance of the UV glue under the lens 7 is small, the reliability is higher, and the coupling efficiency and yield are improved;

[0043] Since the ceramic heat sink 4, the optical fiber array 5 and the lens 7 are all fixed on the upper ceramic substrate 310 in the TEC cooler 3, when the low-cost 400G DR4 optical engine is working at high temperature, the ceramic heat sink 4, the optical fiber array 5 and the lens 7 are all on the cold side of the TEC cooler 3, the temperature difference between them is small, the deformation caused by temperature is small, and the optical path is more stable. When the low-cost 400G DR4 optical engine is working at low temperature, the ceramic heat sink 4, the optical fiber array 5 and the lens 7 are all on the hot side of the TEC cooler 3, the temperature difference between them is also small, the deformation caused by temperature is also small, and the optical path is more stable.

[0044] Four ceramic heat sinks 4 are fixed on the upper surface of the upper ceramic substrate 310 along the width direction of the PCB board 2, and an EML chip 6 coupled to the optical fiber array 5 is fixed on each ceramic heat sink 4. The number of lenses 7 is four, the number of optical isolators 8 is four, and the optical fiber array 5 is a four-channel optical fiber array.

[0045] 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 400G DR4 optical engine, comprising: A base (1) and a PCB (2) placed on the base (1); a through hole (210) penetrating the upper and lower surfaces of the PCB (2) is provided in a partial area corresponding to the base (1); a TEC cooler (3) lower than the upper surface of the PCB (2) is arranged in the through hole (210); a ceramic heat sink (4) bonded to the PCB (2) with gold wires is fixed on the upper surface of an upper ceramic substrate (310) in the TEC cooler (3); an EML chip (6) is fixed on the ceramic heat sink (4); and the TEC cooler (3) is characterized in that: The same end of the upper ceramic substrate (310) and the lower ceramic substrate (320) in the TEC cooler (3) both extend horizontally outwards for a distance in the direction of light propagation, a gap is formed between the outwardly extending sections of the upper ceramic substrate (310) and the lower ceramic substrate (320), a heat insulation board (9) for supporting the upper ceramic substrate (310) is arranged in the gap, and an optical fiber array (5) coupled to an EML chip (6) is fixed on the upper surface of the upper ceramic substrate (310) in the outwardly extending section.

2. A low-cost 400G DR4 optical engine according to claim 1, characterized in that: The heat insulation board (9) and the upper ceramic substrate (310) are bonded together using epoxy structural adhesive (10), and the heat insulation board (9) and the lower ceramic substrate (320) are bonded together using epoxy structural adhesive (10).

3. A low-cost 400G DR4 optical engine according to claim 1 or 2, characterized in that: The material of the heat insulation board (9) is quartz.

4. The low-cost 400G DR4 optical engine according to claim 1, characterized in that: A lens (7) and an optical isolator (8) are sequentially coupled between each EML chip (6) and the optical fiber array (5) along the light propagation direction; the lens (7) is fixed to the upper ceramic substrate (310) using ultraviolet glue; and the optical isolator (8) is fixed on the optical port side of the optical fiber array (5).

5. A low-cost 400G DR4 optical engine according to claim 4, characterized in that: Four ceramic heat sinks (4) are fixed on the upper surface of the upper ceramic substrate (310) along the width direction of the PCB board (2), and each ceramic heat sink (4) is fixed with an EML core coupled to the optical fiber array (5). The sheet (6), the number of the lenses (7) is four, the number of the optical isolators (8) is four, The optical fiber array (5) is a four-channel optical fiber array.

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