Semiconductor refrigerator capable of rapidly heating and rapidly refrigerating

Abstract

The utility model belongs to the technical field of semiconductor coolers, and aims to provide a semiconductor cooler capable of quickly heating and quickly cooling. According to the technical scheme, the semiconductor refrigerator capable of rapidly heating and rapidly refrigerating comprises a cold face ceramic substrate, a first metal circuit layer, a copper flow guide layer, a semiconductor grain layer, a second metal circuit layer and a hot face ceramic substrate which are sequentially laid from top to bottom, and the first metal circuit layer and the copper diversion layer are bonded into a whole through flexible heat-conducting glue. The semiconductor cooler can be used for rapid heating and rapid cooling, and is suitable for application scenes with alternate cooling and heating. And the PCR instrument can quickly perform temperature circulation, thereby being beneficial to shortening the PCR reaction time.

Description

Technical Field

[0001] This utility model belongs to the field of semiconductor refrigerator technology, specifically relating to a semiconductor refrigerator that can both heat up and cool down quickly. Background Technology

[0002] A semiconductor cooler, also known as a thermoelectric cooler, is a device that utilizes the thermoelectric effect of semiconductor materials to achieve cooling or heating functions. For example... Figure 1 As shown, existing semiconductor coolers consist of a semiconductor die layer, positive and negative leads, and two flat DBC (Direct Bond Copper) ceramic substrates. The semiconductor die layer is composed of P-type and N-type semiconductor dies, typically arranged in a series of thermocouple pairs. Each thermocouple pair consists of one P-type and one N-type semiconductor die, connected in series by a metal conductor. The positive and negative leads are connected to electrodes at both ends of the semiconductor die layer. The two ceramic substrates are respectively arranged on the top and bottom surfaces of the semiconductor die layer, with one side of the ceramic substrate forming the cold surface and the other side forming the hot surface. During use, heat can be conducted from the cold surface to the hot surface by driving a direct current, and then the heat is continuously removed from the hot surface by a heat sink.

[0003] However, in using the prior art, the inventors discovered at least the following problems:

[0004] Existing thermoelectric coolers are unsuitable for applications requiring rapid heating and cooling, such as polymerase chain reaction (PCR), which involve alternating hot and cold temperatures. Specifically, due to the significant difference in thermal expansion coefficients between the surface barrier layer of the semiconductor grain layer and the copper sheet of the ceramic substrate, microcracks easily appear at the contact solder joints between them under rapid temperature changes. These microcracks gradually enlarge under alternating hot and cold conditions due to thermal expansion and contraction. Furthermore, the internal resistance of the thermoelectric cooler increases under direct current, thereby weakening its cooling or heating capacity and significantly shortening its lifespan.

[0005] In the field of biological gene detection, PCR instruments are used to amplify specific DNA fragments. This process requires rapid and precise temperature changes, including three stages: denaturation (94°C), annealing (55°C), and amplification (70°C). However, due to the technological limitations of existing semiconductor coolers, it takes at least 40 minutes for existing PCR instruments to complete a full PCR cycle. This not only increases the detection time but may also lead to an increased risk of non-specific amplification and contamination due to prolonged operation, affecting the accuracy of the results. Utility Model Content

[0006] In order to at least partially solve the above-mentioned technical problems, this utility model provides a semiconductor cooler that can both heat up and cool down quickly.

[0007] To achieve the above objectives, the present invention adopts the following technical solution:

[0008] In a first aspect, this utility model discloses a semiconductor cooler that can both heat up and cool down quickly, comprising a cold-side ceramic substrate, a first metal circuit layer, a copper current-conducting layer, a semiconductor grain layer, a second metal circuit layer, and a hot-side ceramic substrate arranged sequentially from top to bottom. The cold-side ceramic substrate uses a ceramic heating element, and the first metal circuit layer and the copper current-conducting layer are bonded together by a flexible thermally conductive adhesive.

[0009] In one possible design, the cold-surface ceramic substrate includes a first ceramic substrate, a metal printing layer, and a second ceramic substrate laid out sequentially from top to bottom. Electrode leads are connected to the two poles of the metal printing layer, and the metal printing layer constitutes the heating wire of the cold-surface ceramic substrate.

[0010] In one possible design, the first ceramic substrate is an aluminum nitride ceramic substrate or an alumina ceramic substrate; the second ceramic substrate is a ceramic substrate made of SiC, SiN, copper, aluminum, molybdenum, titanium, iron or stainless steel; and the metal printing layer is made of tungsten.

[0011] In one possible design, the hot-face ceramic substrate is made of SiC, SiN, copper, aluminum, molybdenum, titanium, iron, or stainless steel.

[0012] In one possible design, the hot-surface ceramic substrate is bonded to the second metal circuit layer using a DBC or DPC process.

[0013] In one possible design, a temperature sensor is provided on the first metal circuit layer and / or the second metal circuit layer.

[0014] In one possible design, a waterproof coating is provided between the first metal circuit layer and the second metal circuit layer, and a sealing structure is provided around the first metal circuit layer and the second metal circuit layer.

[0015] Secondly, this utility model discloses a PCR instrument, including a semiconductor cooler as described in any of the above claims.

[0016] The beneficial effects of this utility model are mainly reflected in:

[0017] 1) Semiconductor coolers can rapidly heat and cool, making them suitable for applications with alternating hot and cold conditions. Specifically, this invention improves upon the traditional DBC ceramic substrate on the cold side of a semiconductor cooler by setting it as an independent copper current-conducting layer, a first metal circuit layer, and a cold-side ceramic substrate. The cold-side ceramic substrate uses a ceramic heating element. When rapid cooling is required, the cold side of the semiconductor cooler in this invention achieves rapid cooling driven by direct current. Since the cold-side ceramic substrate uses a ceramic heating element, it can utilize the rapid heat transfer function of ceramics for heat transfer, and the heating wire in the cold-side ceramic substrate does not participate in the operation. When rapid heating is required, the heating wire in the cold-side ceramic substrate electrically operates to generate heat. The semiconductor cooler can also assist in heating by operating a small current driven by direct current, thereby greatly reducing the operating current of the semiconductor cooler. Simultaneously, most of the stress from thermal expansion and contraction is absorbed by the flexible thermally conductive adhesive, increasing the service life and reliability of the semiconductor cooler in this invention.

[0018] 2) The PCR instrument can quickly cycle the temperature, which helps to shorten the PCR reaction time. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the structure of an existing semiconductor cooler;

[0020] Figure 2 This is a schematic diagram of the semiconductor cooler in Example 1;

[0021] Figure 3 yes Figure 2 The main view;

[0022] Figure 4 yes Figure 2 Top view;

[0023] Figure 5 yes Figure 2 A schematic diagram of the ceramic substrate with a cold front surface;

[0024] Figure 6 yes Figure 5 A diagram from another perspective;

[0025] Figure 7 yes Figure 5 Side view;

[0026] Figure 8 yes Figure 5 A schematic diagram of the structure of the first ceramic substrate and the metal printing layer. Detailed Implementation

[0027] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the present utility model will be briefly introduced below in conjunction with the accompanying drawings and descriptions of the embodiments or the prior art. Obviously, the following description of the structure of the accompanying drawings is only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort. It should be noted that the description of these embodiments is used to help understand this utility model, but does not constitute a limitation on this utility model.

[0028] Example 1:

[0029] like Figures 2 to 4 As shown, this embodiment provides a semiconductor cooler capable of both rapid heating and rapid cooling, comprising, from top to bottom, a cold-side ceramic substrate 1, a first metal circuit layer 2, a copper current-conducting layer 3, a semiconductor grain layer 4, a second metal circuit layer 5, and a hot-side ceramic substrate 6. The cold-side ceramic substrate 1 uses a ceramic heating element, and the first metal circuit layer 2 and the copper current-conducting layer 3 are bonded together using a flexible thermally conductive adhesive. It should be understood that, in this embodiment, the P-type and N-type semiconductor grains in the semiconductor grain layer 4 form a thermocouple pair. The two ends of the thermocouple pair serve as the two poles of the semiconductor grain layer 4, connected to a positive power connection line 7 and a negative power connection line 8, respectively. The positive power connection line 7 and the negative power connection line 8 are used to connect to an external DC power supply, and the magnitude and direction of the current can be adjusted via a preset control circuit board, thereby controlling the cooling or heating function of the semiconductor cooler in this embodiment.

[0030] Specifically, in this embodiment, the semiconductor die layer 4 is composed of multiple P-type semiconductor dies and N-type semiconductor dies, with each P-type semiconductor die and each N-type semiconductor die arranged alternately, and the first metal circuit layer 2, each P-type semiconductor die, each N-type semiconductor die, and the second metal circuit layer 5 are connected in series; in this embodiment, the copper current-conducting layer 3 is used to realize the current-conducting function between the semiconductor die layer 4 and the first metal circuit layer 2, and the copper current-conducting layer 3 includes multiple copper current-conducting strips that are independently connected to the semiconductor dies in the semiconductor die layer 4, and each copper current-conducting strip is independently arranged.

[0031] In this embodiment, the copper current-conducting layer 3 is pre-positioned on a temporary fixture containing high-temperature resistant adhesive using a certain graphic positioning jig. During assembly, multiple bismuth telluride (Bi2Te3)-based N-type and P-type semiconductor grains are first placed between the first metal circuit layer 2 on the cold side and the second metal circuit layer 5 on the hot side. These multiple N-type and P-type semiconductor grains constitute the semiconductor grain layer 4. The N-type and P-type semiconductor grains are arranged in multiple matrix configurations and soldered onto the second metal circuit layer 5 using solder paste. Subsequently, the high-temperature resistant temporary fixture of the copper current-conducting layer 3 is removed, and the copper current-conducting layer 3 is placed over the semiconductor grain layer 4. Finally, the copper current-conducting layer 3 and the first metal circuit layer 2 are pressed and bonded together using thermally conductive adhesive, thereby forming the semiconductor cooler in this embodiment.

[0032] This embodiment can rapidly heat and cool, making it suitable for applications with alternating hot and cold conditions. Specifically, this embodiment improves upon the traditional DBC ceramic substrate on the cold side of a semiconductor cooler by setting it as an independent copper current-conducting layer 3, a first metal circuit layer 2, and a cold-side ceramic substrate 1. The cold-side ceramic substrate 1 uses a ceramic heating element. In cases requiring rapid cooling, the cold side of the semiconductor cooler in this embodiment achieves rapid cooling under the drive of a direct current. At this time, because the cold-side ceramic substrate 1 uses a ceramic heating element, it can utilize the rapid heat transfer function of ceramics for heat transfer, and the heating wire in the cold-side ceramic substrate 1 does not participate in the operation. When rapid heating is required, the heating wire in the cold-side ceramic substrate 1 is electrically activated to generate heat. The semiconductor cooler can also assist in heating by operating a small current under the drive of a direct current, thereby greatly reducing the operating current of the semiconductor cooler. At the same time, most of the stress from thermal expansion and contraction is absorbed by the flexible thermally conductive adhesive, which increases the service life and reliability of the semiconductor cooler in this embodiment.

[0033] In this embodiment, as Figures 5 to 8 As shown, the cold-surface ceramic substrate 1 includes a first ceramic substrate 101, a metal printing layer 102, and a second ceramic substrate 103, which are sequentially laid from top to bottom. Electrode leads 104 are connected to the two poles of the metal printing layer 102, forming the heating wire of the cold-surface ceramic substrate 1. Specifically, in this embodiment, the electrode leads 104 are soldered to the two poles of the metal printing layer 102, thereby ensuring the stability of the electrode lead connections 104. During implementation, current can be supplied to the metal printing layer 102 through the electrode leads 104 to achieve a heating effect.

[0034] In this embodiment, the first ceramic substrate 101 is an aluminum nitride ceramic substrate or an alumina ceramic substrate; the second ceramic substrate 103 is a ceramic substrate made of SiC (silicon carbide), SiN (silicon nitride), copper, aluminum, molybdenum, titanium, iron, or stainless steel; and the metal printing layer 102 is made of tungsten. In this embodiment, the metal printing layer 102 may also use other metal pastes, which are not limited here.

[0035] Specifically, in the process of manufacturing the cold-surface ceramic substrate 1, a pre-designed line pattern is first printed on the surface of the first ceramic substrate 101 using a tungsten or other metal paste. Then, the first ceramic substrate 101 and the second ceramic substrate 103 are overlapped and pressed together. Subsequently, they are sintered in a high-temperature sintering furnace under the protection of hydrogen or other gases, with the sintering temperature range set to 1000℃ to 2200℃. After sintering, the two surfaces of the first ceramic substrate 101 and the second ceramic substrate 103 are ground and polished to ensure the flatness and smoothness of the finished product. Then, the outer dimensions are cut using a laser cutting machine to ensure the accuracy of the outer dimensions of the finished product, thereby obtaining an integrated cold-surface ceramic substrate 1 with a certain resistance.

[0036] In this embodiment, the hot-surface ceramic substrate 6 is a ceramic substrate made of SiC, SiN, copper, aluminum, molybdenum, titanium, iron, or stainless steel.

[0037] Specifically, in this embodiment, the hot-surface ceramic substrate 6 and the second metal circuit layer 5 are bonded using either DBC (Direct Copper Plating) or DPC (Direct Copper Plating) processes. Specifically, DPC is a ceramic circuit fabrication process developed based on ceramic thin-film processing. It uses ceramic as the substrate for the circuit, employs sputtering to deposit a composite metal layer on the substrate surface, and then uses electroplating and photolithography to form the circuit. DBC, on the other hand, uses a hot-melt bonding method to directly sinter copper foil onto the ceramic surface at high temperature to create a composite substrate.

[0038] In this embodiment, a temperature sensor is provided on the first metal circuit layer 2 and / or the second metal circuit layer 5.

[0039] Specifically, in this embodiment, the temperature sensor may be connected to the first metal circuit layer 2 and / or the second metal circuit layer 5 by welding or bonding, which is not limited here.

[0040] In this embodiment, the power supply line of the temperature sensor can be co-located with the positive power connection line 7 and the negative power connection line 8, and the temperature sensor is connected in series with the first metal circuit layer 2 and / or the second metal circuit layer 5. Alternatively, the power supply line of the temperature sensor can be separated from the positive power connection line 7 and the negative power connection line 8, i.e., the temperature sensor is powered separately; this is not restricted here.

[0041] In this embodiment, the temperature sensor is used to detect the temperature of the cold side and / or the hot side, so as to adjust the cooling or heating temperature of the semiconductor cooler by adjusting the magnitude of the DC current, thereby achieving precise temperature control of the semiconductor cooler in this embodiment and improving the temperature consistency of the product during operation.

[0042] The temperature sensor can be a thermocouple, PT00, PT1000, or NTC (Negative Temperature Coefficient) temperature sensor. In this embodiment, the temperature sensor is an NTC temperature sensor, which has the characteristics of high sensitivity and fast response, and can accurately detect minute changes in temperature.

[0043] In this embodiment, a waterproof coating is provided between the first metal circuit layer 2 and the second metal circuit layer 5, and a sealing structure is provided around the first metal circuit layer 2 and the second metal circuit layer 5. Based on this, moisture intrusion can be prevented and insulation improved, while mechanical stability and heat conduction efficiency are enhanced, thereby ensuring the stable operation of the semiconductor cooler in this embodiment.

[0044] Specifically, in this embodiment, a waterproof nano-coating is sprayed between the first metal circuit layer 2 and the second metal circuit layer 5, and a sealing structure such as RTV silicone or epoxy resin is provided around the first metal circuit layer 2 and the second metal circuit layer 5. The waterproof coating, such as Parexel, has excellent waterproof and moisture-proof properties, effectively preventing moisture from entering the interior of the thermoelectric cooler, avoiding electrical short circuits or corrosion caused by moisture, thereby extending the equipment's service life. The RTV (Room Temperature Vulcanization) silicone or epoxy resin sealing structure can fill and seal the tiny gaps around the thermoelectric cooler, and provide additional mechanical support, enhancing the structural strength of the entire component, reducing damage caused by vibration or other external forces, increasing the overall electrical insulation of the structure, reducing the potential risk of electric shock, and improving the safety of the thermoelectric cooler.

[0045] Example 2:

[0046] This embodiment provides a PCR instrument, including a semiconductor cooler as described in any one of Embodiment 1.

[0047] Specifically, PCR is a molecular biology technique used to amplify specific DNA (Deoxyribonucleic acid) fragments. It can be viewed as a special form of DNA replication outside of a living organism, capable of significantly increasing the quantity of minute amounts of DNA. This requires a series of rapid heating and cooling reactions through repeated temperature changes to generate copies of the DNA sequence, making temperature a crucial factor in each stage of PCR. The PCR reaction utilizes three different temperature changes: denaturation, annealing, and amplification, corresponding to 94℃, 55℃, and 70℃ respectively. After 20-40 optimized temperature cycles, a large number of DNA copies can be generated. This process is the most time-consuming part of detection; shortening the PCR cycle time can save time and resources. Simultaneously, rapid temperature changes can reduce PCR errors, minimizing the chance of non-specific amplification and contamination, thus improving the accuracy of the results.

[0048] Since the semiconductor cooler in this embodiment can both heat up and cool down quickly, it is suitable for application scenarios with alternating hot and cold conditions. This allows the PCR instrument in this embodiment to perform temperature cycling quickly and accurately. According to the applicant's experiments, the PCR instrument in this embodiment can complete the entire PCR cycle within 10 minutes, which greatly shortens the PCR reaction time.

[0049] Finally, it should be noted that the above description is merely a preferred embodiment of this utility model and is not intended to limit the scope of protection of this utility model. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this utility model should be included within the scope of protection of this utility model.

Claims

1. A semiconductor refrigerator capable of both rapid heating and rapid cooling, characterized in that: It comprises, from top to bottom, a cold face ceramic substrate (1), a first metal circuit layer (2), a copper conduction layer (3), a semiconductor crystal layer (4), a second metal circuit layer (5) and a hot face ceramic substrate (6), the cold face ceramic substrate (1) adopts a ceramic heating sheet, and the first metal circuit layer (2) and the copper conduction layer (3) are integrated by flexible heat-conducting adhesive.

2. The semiconductor refrigerator capable of rapid heating and rapid cooling according to claim 1, characterized in that: The cold face ceramic substrate (1) comprises, from top to bottom, a first ceramic substrate (101), a metal printing layer (102) and a second ceramic substrate (103), both poles of the metal printing layer (102) are connected with electrode leads (104), and the metal printing layer (102) constitutes a heating wire of the cold face ceramic substrate (1).

3. The semiconductor refrigerator capable of rapid heating and rapid cooling according to claim 2, characterized in that: The first ceramic substrate (101) adopts an aluminum nitride ceramic substrate or an aluminum oxide ceramic substrate; the second ceramic substrate (103) adopts a ceramic substrate of SiC, SiN, copper, aluminum, molybdenum, titanium, iron or stainless steel material; and the metal printing layer (102) adopts metal tungsten.

4. The semiconductor refrigerator capable of rapid heating and rapid cooling according to claim 1, characterized in that: The hot face ceramic substrate (6) adopts a ceramic substrate of SiC, SiN, copper, aluminum, molybdenum, titanium, iron or stainless steel material.

5. The semiconductor refrigerator capable of rapid heating and rapid cooling according to claim 1, characterized in that: The hot face ceramic substrate (6) and the second metal circuit layer (5) are bonded by DBC process or DPC process.

6. The semiconductor refrigerator capable of rapid heating and rapid cooling according to claim 1, characterized by: A temperature sensor is arranged on the first metal circuit layer (2) and / or the second metal circuit layer (5).

7. The semiconductor refrigerator capable of rapid heating and rapid cooling according to claim 1, characterized by: A waterproof coating is arranged between the first metal circuit layer (2) and the second metal circuit layer (5), and a sealing structure is arranged around the first metal circuit layer (2) and the second metal circuit layer (5).

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