Non-airtight packaged light source device and cpo silicon light light engine

Abstract

This utility model relates to a non-hermetically sealed light source device, comprising: a base and a hot-side substrate fixed on the base; a horizontally distributed cold-side substrate is arranged above the hot-side substrate; a passive device is fixed on one side of the upper surface of the cold-side substrate, and at least one heat sink is fixed on the other side; a DFB chip coupled to the passive device is fixed on each heat sink; multiple bismuth telluride cores are fixed between the lower surface of the cold-side substrate and the upper surface of the hot-side substrate in the area corresponding to the DFB chip; multiple bismuth telluride pads of the same height as the bismuth telluride cores are fixed between the lower surface of the cold-side substrate and the upper surface of the hot-side substrate in the area corresponding to the passive device. A CPO silicon photonics engine includes multiple non-hermetically sealed light source devices. The advantages are: it can avoid misalignment of the passive device and the DFB chip in the height direction due to thermal expansion, thus making the optical path more stable; it can ensure that the passive device does not experience low-temperature condensation, nor does it experience excessively high temperatures.

Description

Technical Field

[0001] This utility model relates to the field of light engine technology, specifically to a non-hermetically sealed light source device and a CPO silicon photonics engine. Background Technology

[0002] Traditional CPO silicon photonics engines use hermetically sealed external light source devices. A 16-channel high-power light source is broken down into four BOXes, each containing four DFB chips. Because the hermetically sealed casing and polarization-maintaining fiber in each BOX require gold plating, the cost is high, especially for AI computing power requiring high-power light source devices (200mW / single channel or higher). To reduce costs while meeting high power requirements, non-hermetically sealed light source devices have emerged. Due to the high optical power requirements and power consumption of a single DFB chip, TEC cooling is required to ensure the DFB chip temperature remains below 50℃ (generally required to be between 30℃ and 50℃) to guarantee chip luminous efficiency. Two types of non-hermetically sealed light source devices exist for this purpose, as follows:

[0003] 1) The non-hermetic packaged light source device includes: a base, a mounting pad bonded to one side of the upper surface of the base, and a TEC (Transformer Electrode Array) arranged on the other side. The hot-side substrate of the TEC is located below and bonded to the base. At least one heat sink is fixed on the cold-side substrate of the TEC, and one DFB (Digital Bulb) chip is fixed on each heat sink. Based on the aforementioned four DFB chips per box, four heat sinks are fixed on the cold-side substrate of the TEC, thus providing four DFB chips. Passive devices coupled to all DFB chips are fixed on the pad. These passive devices include: an optical fiber array fixed to the upper surface of the cold-side substrate; an optical isolator fixed to the cold-side substrate and coupled to each channel on the light-incident side of the optical fiber array; and a lens fixed to the cold-side substrate and coupled between each DFB chip and the optical isolator. The base is made of tungsten copper, the heat sink is made of ceramic, the pad is made of ceramic, and the hot-side and cold-side substrates of the TEC are made of ceramic. (Specific details are as follows...) Figure 1 As shown, in this scheme, the passive device's temperature is very high, generally >85℃, due to the bonding between the pad and the base, and the bonding between the hot-side substrate of the TEC and the base. The reasons are as follows: the temperature difference and the different coefficients of thermal expansion of the materials cause the thermal expansion of the passive device to be inconsistent with that of the DFB chip (especially in the height direction, due to the large tolerance of the TEC and the large differences in material assembly, the DFB chip and the passive device are misaligned in the height direction), which affects the high-temperature coupling efficiency, thus resulting in lower optical power of the non-hermetically sealed light source device under high-temperature operation.

[0004] 2) The non-hermetic-sealed light source device includes: a base and a TEC (Transmission Equipment). The hot-side substrate of the TEC is located below and bonded to the base. On the upper surface of the cold-side substrate of the TEC, a passive device is fixed on one side, and at least one heat sink is fixed on the other side. Each heat sink has a DFB (Digital Bulb) chip coupled to the passive device. Based on the aforementioned four DFB chips per BOX, the TEC has four heat sinks fixed on its cold-side substrate, thus having four DFB chips. The passive device includes: an optical fiber array fixed to the upper surface of the cold-side substrate. On the light-incident side of the optical fiber array, each channel is coupled to an optical isolator fixed to the cold-side substrate. Each DFB chip is coupled to an optical isolator, and a lens fixed to the cold-side substrate is coupled between the optical fiber array and the optical isolator. Specifically, as shown... Figure 2 As shown, the base material is tungsten copper, the heat sink material is ceramic, and the hot and cold side substrates of the TEC are also made of ceramic. In this design, the DFB chip and passive devices are all located on the TEC, meaning the passive devices are on the cold side substrate of the TEC. Due to the significant heat generated by the DFB chip, the temperature of the cold side substrate in the TEC below the DFB chip is maintained between 5°C and 20°C. However, the passive devices do not generate heat, resulting in the temperature of the cold side substrate in the TEC below the passive devices being below 5°C. In particular, the temperature of the fiber array will be below 0°C, leading to condensation. The condensation on the fiber core of the fiber array will result in low optical power. When the non-hermetic packaged light source device operates at a low temperature of 0°C, the TEC can operate in reverse, i.e., the current direction is reversed (the cold side of the TEC becomes the hot side, and the hot side of the TEC becomes the cold side). When the TEC becomes the cold side and contacts the base, the temperature of the cold side is below 0°C, and condensation will occur on the cold side, which may cause the TEC to short-circuit and fail. Utility Model Content

[0005] The technical problem to be solved by this utility model is to provide a non-hermetic packaged light source device and a CPO silicon photonic engine to overcome the shortcomings of the prior art.

[0006] The technical solution of this utility model to solve the above-mentioned technical problems is as follows:

[0007] A non-hermetic-sealed light source device includes: a base and a hot-side substrate fixed on the base; a horizontally distributed cold-side substrate is disposed above the hot-side substrate; a passive device is fixed on one side of the upper surface of the cold-side substrate, and at least one heat sink is fixed on the other side; a DFB chip coupled to the passive device is fixed on each heat sink; multiple bismuth telluride cores are fixed between the lower surface of the cold-side substrate and the upper surface of the hot-side substrate in the region corresponding to the DFB chip; and multiple bismuth telluride pads of the same height as the bismuth telluride cores are fixed between the lower surface of the cold-side substrate and the upper surface of the hot-side substrate in the region corresponding to the passive device.

[0008] The beneficial effects of this invention are as follows: Using this packaging method, since the passive device and the DFB chip are relatively located on a cold-side substrate, misalignment in the height direction due to thermal expansion can be avoided, thus making the optical path more stable. Furthermore, only the area below the DFB chip between the hot and cold-side substrates has a bismuth telluride core with cooling function, while the area corresponding to the passive device uses a bismuth telluride pad that only provides support. When the DFB chip is working, the bismuth telluride core can cool the area, keeping the temperature of the cold-side substrate below the DFB chip between 5℃ and 20℃. Bismuth telluride has a certain thermal conductivity, which can conduct some of the heat from the hot-side substrate to the cold-side substrate. However, the temperature near the lens in the passive device can be controlled at 20℃±5℃, the temperature near the optical isolator in the passive device can be controlled at 30℃±5℃, and the temperature near the fiber array in the passive device can be controlled at 40℃±5℃. This ensures that the passive device (especially the fiber array) does not experience low-temperature condensation and does not overheat.

[0009] Based on the above technical solution, the present invention can be further improved as follows.

[0010] Furthermore, the bismuth telluride core is electrically connected to the first electrode on the hot-side substrate, and the first electrode and the DFB chip are electrically connected to the FPC board respectively.

[0011] The further beneficial effect of adopting the above is that the FPC board and the first electrode can supply power to the bismuth telluride core, so that it can start cooling.

[0012] Furthermore, a thin-film heating resistor is fixed on the lower surface of the cold-side substrate, and the thin-film heating resistor is electrically connected to the second electrode on the upper surface of the hot-side substrate. A thermistor is arranged on the base, and the second electrode and the thermistor are electrically connected to the FPC board respectively.

[0013] The further beneficial effects of the above are as follows: when the non-hermetic light source device is at a low temperature, that is, when the temperature measured by the thermistor is below 20°C, the bismuth telluride core stops working, and then the thin film heating resistor starts to work with current. Since the thin film heating resistor is a pure resistor that only generates heat, it can heat the cold surface substrate, making the temperature of the cold surface substrate greater than 15°C, so that condensation will not occur, and at the same time, the temperature measured by the thermistor is 15°C to 25°C.

[0014] Furthermore, the thin-film heating resistors are distributed in a meandering pattern among multiple bismuth telluride cores and multiple bismuth telluride pads.

[0015] Furthermore, multiple bismuth telluride core particles are evenly distributed in a multi-row, multi-column configuration.

[0016] Furthermore, multiple bismuth telluride pads are evenly distributed in a multi-row, multi-column configuration.

[0017] Furthermore, the hot-side substrate, cold-side substrate, and heat sink are all made of ceramic, while the base is made of tungsten copper.

[0018] Furthermore, the passive device includes: an optical fiber array fixed on the upper surface of the cold-surface substrate, with each channel on the light-incident side of the optical fiber array coupled with an optical isolator fixed to the cold-surface substrate, and each DFB chip coupled with an optical isolator and a lens fixed to the cold-surface substrate.

[0019] Based on the above technical solution, this utility model also provides a CPO silicon photonics engine, including: a plurality of the above-mentioned non-hermetically sealed light source devices.

[0020] The further beneficial effects of adopting the above are: the optical path is more stable, and it can ensure that passive devices (especially fiber arrays) do not have low-temperature condensation, nor does it have excessively high temperature. Attached Figure Description

[0021] Figure 1 This is a diagram of the first type of packaging structure for non-hermetic-sealed light source devices in the prior art.

[0022] Figure 2 This is a diagram of a second type of packaging structure for non-hermetic-sealed light source devices in the prior art;

[0023] Figure 3 This is a first packaging structure diagram of the non-hermetically sealed light source device in this utility model;

[0024] Figure 4 This is a second packaging structure diagram of the non-hermetically sealed light source device in this utility model;

[0025] Figure 5 This is a top view of the non-hermetically sealed light source device of this utility model.

[0026] The attached diagram lists the components represented by each number as follows:

[0027] 1. Base, 2. Cold side substrate, 3. Hot side substrate, 4. Heat sink, 5. DFB chip, 6. Bismuth telluride core, 7. First electrode, 8. FPC board, 9. Bismuth telluride pad, 10. Thin film heating resistor, 11. Second electrode, 12. Thermistor, 13. Fiber optic array, 14. Optical isolator, 15. Lens. Detailed Implementation

[0028] The principles and features of this utility model are described below with reference to the accompanying drawings. The examples given are only for explaining this utility model and are not intended to limit the scope of this utility model.

[0029] Example 1

[0030] like Figure 3As shown, a non-hermetic-sealed light source device includes: a base 1, a hot-side substrate 3 bonded and fixed on the base 1, and a horizontally distributed cold-side substrate 2 disposed above the hot-side substrate 3. A passive device is fixed on one side of the upper surface of the cold-side substrate 2, and at least one heat sink 4 is fixed on the other side of the upper surface of the cold-side substrate 2. Each heat sink 4 has a DFB chip 5 coupled to the passive device fixed on it. Based on the prior art, the actual number of heat sinks 4 is four, the actual number of DFB chips 5 is four, and the passive device has four channels. Multiple bismuth telluride cores 6 are fixed between the lower surface of the cold-side substrate 2 and the upper surface of the hot-side substrate 3 in the area corresponding to the DFB chip 5. Multiple bismuth telluride pads 9 are fixed between the lower surface of the cold substrate 2 and the upper surface of the hot substrate 3 in the area corresponding to the passive device. The bismuth telluride pads 9 are at the same height as the bismuth telluride core 6. The bismuth telluride pads 9 do not have a cooling function; they are used to support the cold substrate 2. The thermal conductivity of bismuth telluride is 1W / mk to 1.6W / mk. In this scheme, the hot substrate 3, cold substrate 2, bismuth telluride core 6, and bismuth telluride pads 9 are all components in the new TEC. In this packaging method, since the passive device and the DFB chip 5 are relatively located on the same cold substrate 2, it can avoid the passive device and the DFB chip 5 from being misaligned in the height direction due to thermal expansion, thus making the optical path more stable. Moreover, only the area below the DFB chip 5 between the hot substrate 3 and the cold substrate 2 has a bismuth telluride core 6 with a cooling function. The area corresponding to passive devices uses bismuth telluride pads 9 that only serve a supporting function. When the DFB chip 5 is working, the bismuth telluride cores 6 can cool the area, keeping the temperature of the cold substrate 2 below the DFB chip 5 between 5℃ and 20℃. Bismuth telluride has a certain thermal conductivity, which can conduct some of the temperature of the hot substrate 3 to the cold substrate 2. However, the temperature of the lens near the passive device can be controlled at 20℃±5℃, the temperature of the optical isolator near the passive device can be controlled at 30℃±5℃, and the temperature of the fiber array near the passive device can be controlled at 40℃±5℃. This ensures that there is no low-temperature condensation in the passive devices (especially the fiber array) and that the temperature does not become too high. The number and position of the bismuth telluride cores 6 can be adjusted and optimized during testing based on the actual temperature measurement results (position fine-tuning).

[0031] Example 2

[0032] like Figure 3 As shown, this embodiment is a further improvement on embodiment 1, as detailed below:

[0033] The bismuth telluride core 6 is electrically connected to the first electrode 7 on the hot surface substrate 3. The first electrode 7 and the DFB chip 5 are electrically connected to the FPC board 8 respectively. The FPC board 8 and the first electrode 7 can supply power to the bismuth telluride core 6 so that it can start cooling.

[0034] Example 3

[0035] like Figure 4 , Figure 5 As shown, this embodiment is a further improvement on embodiment 1 or 2, as detailed below:

[0036] A thin-film heating resistor 10 is fixed on the lower surface of the cold-side substrate 2. The thin-film heating resistor 10 is electrically connected to the second electrode 11 on the upper surface of the hot-side substrate 3. A thermistor 12 is arranged on the base 1. The second electrode 11 is electrically connected to the FPC board 8, and the thermistor 12 is electrically connected to the FPC board 8. When the non-hermetically sealed light source device is at a low temperature, that is, when the temperature measured by the thermistor 12 is below 20°C, the bismuth telluride core 6 stops working, and then the thin-film heating resistor 10 starts to apply current. Since the thin-film heating resistor 10 is a pure resistor and only generates heat, it can heat the cold-side substrate 2, making the temperature of the cold-side substrate 2 greater than 15°C, so that condensation will not occur. At the same time, the temperature measured by the thermistor 12 is 15°C to 25°C.

[0037] Furthermore, the thin-film heating resistor 10 is distributed in a meandering manner among multiple bismuth telluride cores 6 and multiple bismuth telluride pads 9, such as... Figure 5 As shown, the detour is W-shaped.

[0038] Example 4

[0039] like Figure 3 , Figure 4 As shown, this embodiment is a further improvement on any one of embodiments 1 to 3, as detailed below:

[0040] Multiple bismuth telluride cores 6 are evenly distributed in a multi-row, multi-column manner. For example, as shown in the figure, they are evenly distributed in a three-row, seven-column manner. This is just an exemplary description. In actual applications, other forms are not excluded, such as a four-row, six-column manner, etc.

[0041] Multiple bismuth telluride pads 9 are evenly distributed in a multi-row, multi-column manner, for example, as shown in the figure, they are evenly distributed in a five-row, seven-column manner. This is just an exemplary description. In actual applications, other forms are not excluded, such as a six-row, six-column even distribution, etc.

[0042] Example 5

[0043] like Figure 3 , Figure 4 , Figure 5 As shown, this embodiment is a further improvement on any one of embodiments 1 to 4, as detailed below:

[0044] The hot side substrate 3 is made of ceramic, the cold side substrate 2 is made of ceramic, and the heat sink 4 is made of ceramic, which is consistent with the existing technology. The thermal conductivity of ceramic is 230±5W / mk. The base 1 is made of tungsten copper, which is also consistent with the existing technology.

[0045] Example 6

[0046] like Figure 3 , Figure 5 As shown, this embodiment is a further improvement on any one of embodiments 1 to 5, as detailed below:

[0047] The passive device includes: an optical fiber array 13 fixed on the upper surface of the cold surface substrate 2, with each channel of the optical fiber array 13 having an optical isolator 14 fixed to the cold surface substrate 2 coupled to it, and each DFB chip 5 having a lens 15 fixed to the cold surface substrate 2 coupled to the optical isolator 14. In other words, the passive device remains consistent with the existing technology.

[0048] Example 7

[0049] A CPO silicon photonics engine includes: a plurality of non-hermetic light source devices as described in any of the embodiments 1 to 6.

[0050] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention.

Claims

1. A non-hermetic-sealed light source device, characterized in that, include: A base (1) and a hot surface substrate (3) fixed on the base (1). A horizontally distributed cold surface substrate (2) is arranged above the hot surface substrate (3). A passive device is fixed on one side of the upper surface of the cold surface substrate (2), and at least one heat sink (4) is fixed on the other side. A DFB chip (5) coupled to the passive device is fixed on each heat sink (4). Multiple bismuth telluride core particles (6) are fixed between the lower surface of the cold surface substrate (2) and the upper surface of the hot surface substrate (3) in the area corresponding to the DFB chip (5). Multiple bismuth telluride pads (9) of the same height as the bismuth telluride core particles (6) are fixed between the lower surface of the cold surface substrate (2) and the upper surface of the hot surface substrate (3) in the area corresponding to the passive device.

2. The non-hermetic-sealed light source device according to claim 1, characterized in that, The bismuth telluride core (6) is electrically connected to the first electrode (7) on the hot surface substrate (3), and the first electrode (7) and the DFB chip (5) are electrically connected to the FPC board (8).

3. A non-hermetic-sealed light source device according to claim 1 or 2, characterized in that, A thin-film heating resistor (10) is fixed on the lower surface of the cold-side substrate (2). The thin-film heating resistor (10) is electrically connected to a second electrode (11) on the upper surface of the hot-side substrate (3). A thermistor (12) is arranged on the base (1). The second electrode (11) and the thermistor (12) are electrically connected to the FPC board (8) respectively.

4. A non-hermetic-sealed light source device according to claim 3, characterized in that, The thin-film heating resistor (10) is distributed in a meandering manner among multiple bismuth telluride cores (6) and multiple bismuth telluride pads (9).

5. A non-hermetic-sealed light source device according to claim 1, characterized in that, Multiple bismuth telluride core particles (6) are evenly distributed in multiple rows and columns.

6. A non-hermetic-sealed light source device according to claim 1, characterized in that, Multiple bismuth telluride pads (9) are evenly distributed in a multi-row, multi-column manner.

7. A non-hermetic-sealed light source device according to claim 1, characterized in that, The hot side substrate (3), cold side substrate (2) and heat sink (4) are all made of ceramic, and the base (1) is made of tungsten copper.

8. A non-hermetic-sealed light source device according to claim 1, characterized in that, The passive device includes: an optical fiber array (13) fixed on the upper surface of the cold surface substrate (2), and each optical fiber array (13) is coupled to an optical isolator (14) fixed to the cold surface substrate (2) on the light input side of each channel. Each DFB chip (5) is coupled to a lens (15) fixed to the cold surface substrate (2) between itself and the optical isolator (14).

9. A CPO silicon photonics engine, characterized in that, include: Multiple non-hermetic packaged light source devices as described in any one of claims 1 to 8.

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