A temperature-controlled AD converter testing device

Abstract

The utility model relates to a kind of temperature control type AD converter testing device, it includes: test fixture body, for installing AD converter to be detected;Cooling assembly, including the cooling plate being set in test fixture body bottom and the cooling module being set with cooling plate adhesion, several cooling channels are connected in parallel inside cooling module, several cooling channels are respectively communicated with inlet manifold and liquid-collecting manifold, and the cross section of each cooling channel gradually increases along the flow direction of cooling liquid;The side of cooling plate facing AD converter to be detected is heat conduction contact surface, and heat coupling is formed with the heat dissipation side of AD converter by heat conduction interface material;Temperature control structure, with inlet manifold and liquid-collecting manifold are communicated to form cooling liquid circulation passageway, for adjusting the temperature and / or flow of cooling liquid to maintain set temperature;Test module, with AD converter to be detected electric connection.

Description

Technical Field

[0001] This utility model relates to the field of electronic testing equipment technology, and in particular to a temperature-controlled AD converter testing device. Background Technology

[0002] AD converters are widely used in high-precision measurement and data acquisition, and their performance is extremely sensitive to operating temperature. To obtain repeatable and comparable test data, existing test equipment is usually equipped with temperature control functions, using methods such as cooling plates, constant temperature stages, liquid cooling / air cooling, or thermoelectric cooling (TEC) to manage the thermal of the chip under test. A common practice is to make the cooling plate have a large contact area with the bottom surface of the chip and to arrange constant cross-section flow channels within the cooling plate to increase the heat exchange area and reduce the chip junction temperature, thereby enabling parameter and functional testing at different temperature points.

[0003] However, in practical applications, multiple bottlenecks are typically encountered: First, the flatness error of the package bottom surface leads to a larger contact thermal resistance, limiting the uniformity of heat dissipation; second, the difference in the coefficients of thermal expansion between the chip material and the cooling plate metal material can easily cause thermal stress accumulation during temperature cycling, resulting in solder joint failure or device damage; third, the full contact structure can easily interfere with pin leads and high-precision signal wiring, increasing the risk of electromagnetic interference and noise; fourth, condensation may occur on the large-area cooling surface under high humidity or large temperature difference conditions, leading to insulation and short-circuit hazards; fifth, the uneven flow distribution and response lag of traditional equal-section cooling channels can promote local hot spots and reduce the stability and reliability of test data.

[0004] Therefore, there is an urgent need for a temperature-controlled AD converter testing device to effectively reduce contact thermal resistance, improve temperature field uniformity, and improve flow distribution while ensuring electrical connection and anti-interference requirements, thereby improving the temperature stabilization speed and the consistency and reliability of test results. Utility Model Content

[0005] This invention aims to solve at least one of the technical problems existing in the prior art. To this end, one objective of this invention is to provide a temperature-controlled AD converter testing device, comprising: a test fixture body for mounting the AD converter under test; a cooling assembly including a cooling plate disposed at the bottom of the test fixture body and a cooling module fitted to the cooling plate, wherein the cooling module has several cooling channels arranged in parallel, the cooling channels being respectively connected to an inlet manifold and a collector manifold, and the cross-section of each cooling channel gradually increasing along the flow direction of the coolant; the side of the cooling plate facing the AD converter under test is a thermally conductive contact surface, and thermally coupled to the heat dissipation side of the AD converter through a thermally conductive interface material; a temperature control structure, connected to the inlet manifold and the collector manifold to form a coolant circulation path, used to adjust the temperature and / or flow rate of the coolant to maintain a set temperature; and a test module, electrically connected to the AD converter under test, used to provide power, reference voltage, and clock / excitation signals to the AD converter under test, and to acquire its output signal to complete the test.

[0006] In one possible implementation, the cross-sectional area of ​​each cooling channel gradually increases linearly along the flow direction of the coolant.

[0007] In one possible implementation, the temperature control structure includes: a temperature sensor disposed in the region of the inlet manifold, the collector manifold, and / or the cooling plate near the AD converter, for detecting the temperature of the measured region; and a temperature controller electrically connected to the temperature sensor and receiving its detection signal, and adjusting the temperature and / or flow rate of the coolant in the coolant circulation path based on the detection signal to maintain a set temperature in the measured region.

[0008] In one possible implementation, the temperature control structure includes: a flow actuator electrically connected to the temperature controller, used to adjust the coolant flow rate and / or pressure difference in the coolant circulation path according to the control signal of the temperature controller, the flow actuator being disposed on the coolant circulation path between the inlet manifold and the collector manifold; and a temperature actuator electrically connected to the temperature controller, used to cool and / or heat the coolant to regulate its temperature, the temperature actuator being disposed on the coolant circulation path and / or thermally coupled to the back of the cooling plate.

[0009] In one possible implementation, the flow actuator is a circulation pump connected in series in the coolant circulation path upstream of the inlet manifold to provide an adjustable flow rate.

[0010] In one possible implementation, the temperature actuator is a heat exchanger connected in series with the coolant circulation path to exchange heat with the coolant.

[0011] In one possible implementation, the temperature sensor includes at least a first thermometer and a second thermometer, used to detect the coolant temperature on the side entering the cooling module and the coolant temperature on the side leaving the cooling module, respectively; the temperature controller is used to determine the temperature difference based on the detection results of the first thermometer and the second thermometer and use it as the basis for temperature control.

[0012] In one possible implementation, the temperature controller employs a closed-loop temperature control strategy, which is one of PID control, cascade control, or control with feedforward compensation, to maintain the temperature of the measured area at a set value.

[0013] In one possible implementation, the thermal interface material is at least one of thermal grease, phase change material, or graphite sheet.

[0014] In one possible implementation, the inlet manifold and / or the collector manifold are provided with tapered or diffuser sections along their length to improve the uniformity of flow distribution in the parallel cooling channels.

[0015] Additional aspects and advantages of this invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Based on the above technical solution, the temperature-controlled AD converter testing device provided by this utility model, while ensuring electrical connection and anti-interference requirements, constructs an efficient thermal coupling path by setting a cooling plate and parallel cooling modules under the test fixture body, and introducing a thermally conductive interface material between the cooling plate and the AD converter, effectively reducing contact thermal resistance. Specifically, the cooling module has several cooling channels inside, and the cross-section of each cooling channel gradually increases along the coolant flow direction, thereby optimizing the fluid resistance distribution and improving the uniformity of flow distribution between parallel channels. The coolant circulates under the action of the temperature control structure, and the temperature and flow rate are adjustable. It is stably conducted to the heat dissipation side of the AD converter through the cooling plate, realizing rapid temperature response and precise temperature control. The thermally conductive interface material makes the working surface of the AD converter form a more uniform temperature field, avoiding local overheating or overcooling. At the same time, the test module provides a stable power supply, reference voltage, and clock / excitation signal, and collects its output to ensure that the test process is carried out in a temperature-controlled environment. In summary, this testing device improves the temperature stabilization speed and thermal field uniformity through structural optimization and temperature control coordination, thereby effectively improving the consistency and reliability of test results and solving key problems in existing technologies such as high contact thermal resistance, slow temperature control response, uneven temperature field distribution, and poor flow distribution. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this utility model. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0017] Figure 1 This is a schematic diagram of the structure of the temperature-controlled AD converter testing device provided in an embodiment of the present invention; Figure 2 for Figure 1 An enlarged schematic diagram of the cooling plate in the device shown; Figure 3 for Figure 1 An enlarged schematic diagram of the components in the device shown.

[0018] Explanation of reference numerals in the attached figures: 1. Test fixture body; 2. Cooling assembly; 3. Cooling plate; 4. Cooling module; 5. Cooling channel; 6. Liquid inlet manifold; 7. Liquid collection manifold; 8. Temperature control structure; 9. Test module; 10. Flow actuator; 11. Temperature actuator; 12. First thermometer; 13. Second thermometer. Detailed Implementation

[0019] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of this utility model.

[0020] In the description of this utility model, it should be understood that the terms "center," "longitudinal," "transverse," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential," etc., indicating the orientation or positional relationship shown in the accompanying drawings, are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model. Furthermore, features defined with "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this utility model, unless otherwise stated, "a plurality of" means two or more.

[0021] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0022] The embodiments of this utility model are described in detail below. Examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this utility model, and should not be construed as limiting this utility model.

[0023] Figure 1 This is a schematic diagram of the structure of the temperature-controlled AD converter testing device provided in an embodiment of the present invention; Figure 2 for Figure 1 An enlarged schematic diagram of the cooling plate in the device shown; Figure 3 for Figure 1 An enlarged schematic diagram of the components in the device shown.

[0024] Please see Figure 1-3 In one possible implementation, the system includes: a test fixture body 1 for mounting the AD converter to be tested; a cooling assembly 2 including a cooling plate 3 disposed at the bottom of the test fixture body 1 and a cooling module 4 disposed in contact with the cooling plate 3, wherein a plurality of cooling channels 5 are arranged in parallel inside the cooling module 4, the channels being respectively connected to an inlet manifold 6 and a collecting manifold 7, and the cross-section of each channel gradually increases along the flow direction of the coolant; the side of the cooling plate 3 facing the AD converter to be tested is a thermally conductive contact surface, and thermally coupled to the heat dissipation side of the AD converter through a thermally conductive interface material; a temperature control structure 8 is connected to the inlet manifold 6 and the collecting manifold 7 to form a coolant circulation path, used to adjust the temperature and / or flow rate of the coolant to maintain a set temperature; and a test module 9 electrically connected to the AD converter to be tested, used to provide it with power, reference voltage and clock / excitation signals, and to acquire the output signal to complete the test.

[0025] The test fixture body 1 is preferably machined from a single piece of aluminum or copper alloy. The top is equipped with a positioning cavity and clamping mechanism that match the device package to achieve stable clamping and repeatable positioning under thermo-electric coupling conditions. The cooling plate 3 is detachably connected to the test fixture body 1 via fasteners. The thermally conductive contact surface facing the device is precision milled and ground, with a surface roughness preferably not exceeding Ra 0.8 μm. The cooling module 4 is fully fitted to the back of the cooling plate 3. The internal parallel cooling channels 5 reduce local high flow velocities and excessive pressure drops at the inlet section by gradually increasing effective cross-sections in the flow direction. The channels can have rectangular or semi-circular cross-sections, with typical dimensions of 0.5–2.0 mm width and 0.3–1.5 mm depth. The cross-sectional growth ratio from inlet to outlet can be 1.1–1.6. Each channel inlet is connected to the inlet manifold 6, and the outlet is connected to the collection manifold 7. The flow channel cross-sections and distribution positions of the manifolds are symmetrically arranged to reduce the pressure drop difference between branches. A thermally conductive interface material, such as thermally conductive silicone grease or phase change material, is filled between the cooling plate 3 and the heat dissipation side of the device. The clamping mechanism provides a surface pressure of approximately 50–200 kPa under a uniformly distributed load, forming a low-thermal-resistance, repeatable thermal coupling path. The temperature control structure 8 drives the coolant to flow in the circulation path. Commonly used working fluids are deionized water-ethylene glycol mixtures or dielectric fluorinated liquids, with a flow rate range of, for example, 0.2–1.5 L / min. The supply temperature can be set between –20 °C and 125 °C. The temperature of the measured area is stabilized near the set value by adjusting the temperature and / or flow rate of the temperature control structure 8, with a typical steady-state deviation controllable within ±0.1–±0.3 °C. Test module 9 is electrically connected to the device via a dedicated high-precision socket or probe socket, providing a low-noise programmable power supply, a stable reference voltage source, and a low-jitter clock / excitation signal (clock jitter preferably less than 200 fsrms). The front end is equipped with anti-aliasing filtering and reasonable shielding, grounding, and trace isolation. The output signal is recorded and analyzed by data acquisition and host computer software to complete the multi-temperature test process for indicators such as zero point, gain, INL / DNL, SNR / ENOB, etc.

[0026] Specifically, the coolant is distributed into each parallel channel through the inlet manifold 6. Because the channel cross-section gradually increases along the flow path, the pressure drop distribution along the path is smoother, the flow rate distribution tends to be more balanced, and the heat transfer flux distribution on the back of the cooling plate 3 is more consistent. Through the low thermal resistance path formed by the cooling plate 3 and the thermally conductive interface material, the heat generated by the device operation is promptly carried away, allowing the measured area near the chip to quickly reach and maintain the set temperature. When a power consumption step or ambient temperature change occurs, the temperature control structure 8 suppresses temperature deviation by adjusting the supply temperature and / or circulation flow rate, restoring the temperature of the device contact area of ​​the cooling plate 3 to the set value. The test module 9 provides a low-noise power supply and a high-stability reference under stable thermal conditions, while driving the sampling process with a low-jitter clock. The measured output signal enters the analysis through the acquisition link, avoiding interference from electromagnetic and mechanical vibrations of the cooling system on the measurement.

[0027] This implementation significantly improves the temperature field uniformity of the cooling plate 3 surface, reduces the in-plane temperature gradient of the chip, and reduces the deviation caused by temperature drift in static and dynamic parameter testing. The high flatness of the contact surface, combined with the thermally conductive interface material, reduces contact thermal resistance and improves temperature response speed and temperature control accuracy. Stable temperature control is achieved over a wide temperature range, making cross-temperature point testing more repeatable and comparable. The power supply, reference, and clock quality are fully utilized under stable thermal conditions, and the test results better reflect the intrinsic performance of the device, facilitating batch consistency evaluation and production screening.

[0028] Please see Figure 2 In one possible implementation, the cross-sectional area of ​​each cooling channel 5 gradually increases linearly along the flow direction of the coolant.

[0029] The channel can have a rectangular or near-rectangular cross-section, with linear area growth achieved through linear taper in width or depth. Let the effective channel length be L, the cross-sectional area at the entrance be A0, and the coordinate along the path be x (from the entrance). Then the cross-sectional area varies linearly according to A(x) = A0 + k·x, where k is a positive area gradient constant. To facilitate processing and consistency control, this rule is often achieved by using a constant depth combined with linearly varying width, i.e., w(x) = w0 + k_w·x, h is constant; or by using a constant width combined with linearly increasing depth, i.e., h(x) = h0 + k_h·x, w is constant. Typical dimensions are: length 20–50 mm, entrance width 0.5–0.8 mm, exit width 0.9–1.5 mm, depth 0.3–1.0 mm; when using a constant depth scheme, the area gradient is determined by the width gradient. During machining, CNC precision milling or etching + bonding can be used to form a linear taper. The linearity tolerance of the channel boundary is preferably controlled within ±0.03 mm, and the surface roughness is preferably no higher than Ra 1.6 μm. The parallel channel is connected to the inlet manifold 6 at the inlet end and to the collection manifold 7 at the outlet end. All branches use the same L, A0, and k to ensure consistent hydraulic characteristics. If the layout constraints cause slight differences in L, the equivalent hydraulic resistance can be kept consistent by fine-tuning k. To improve manufacturability, the continuous linear taper can be discretized into several equal-length segments, with the width of each segment increasing in an arithmetic progression. The number of segments can be 8–20, approximating a linear change in a stepwise manner.

[0030] Specifically, as the coolant enters each channel inlet, the local flow velocity and dynamic pressure are suppressed in the inlet section due to the linear increase in cross-sectional area along the flow path, resulting in a smoother pressure drop distribution along the path. The pressure drop difference between parallel branches is reduced, and the flow distribution is more balanced, thus making the heat transfer flux of the contact area between the cooling plate 3 and the device under test more consistent. Compared with a channel with a constant cross-section, the linear taper weakens the "flow grabbing" effect in the inlet section and avoids stagnation caused by excessive deceleration in the outlet section, balancing uniformity and overall pressure drop. Combined with a thermally conductive interface material and a highly flat contact surface, the linear area distribution of the channel helps to reach the set temperature more quickly and stabilize rapidly after disturbances. During the design, the equivalent hydraulic resistance of a single channel can be estimated first according to the target total flow rate and allowable pressure drop, and then A0 and k can be calculated in reverse. To avoid noise and vibration caused by excessively high local Reynolds numbers, the Reynolds number in the inlet section should be controlled below the critical value, and if necessary, constraints can be imposed by increasing A0 or reducing the total flow rate.

[0031] This implementation significantly improves the flow distribution and temperature field uniformity of the parallel system while maintaining processing simplicity, reducing in-plane temperature difference and the resulting parameter drift. The linearity facilitates analytical design and dimensional calibration, making manufacturing and inspection more intuitive. Under the same total flow rate and allowable pressure drop, a more stable steady-state temperature and faster transition response can be obtained, thereby improving the repeatability and data consistency of cross-temperature point testing. In one possible implementation, the temperature control structure 8 includes a temperature sensor located in the area near the AD converter of the inlet manifold 6, the collector manifold 7, and / or the cooling plate 3, for detecting the temperature of the measured area; it also includes a temperature controller electrically connected to the temperature sensor and receiving its detection signal, adjusting the coolant temperature and / or flow rate in the coolant circulation path based on the detection signal to maintain the measured area at a set temperature.

[0032] Temperature sensors can be selected from thin-film platinum resistance thermometers (such as PT100 or PT1000, preferably A or higher), NTC thermistors, or insulated thermocouples. Blind holes can be machined into the cooling plate 3 near the device to fix the temperature sensor using thermally conductive potting compound or threaded clamping, ensuring the sensing end is no more than 2–3 mm away from the thermally conductive contact surface between the cooling plate 3 and the device, thus shortening the thermal path and reducing hysteresis. One temperature sensor is installed at each of the inlet manifold 6 and the outlet manifold 7 to measure the temperature of the coolant entering and leaving the cooling module 4, thereby obtaining the temperature difference and monitoring the heat transfer intensity to determine whether thermal steady state has been reached. The sensor leads use a four-wire or three-wire connection (for platinum resistance thermometers) and are led out with shielded twisted wire. The shielding layer is grounded at a single point to avoid electromagnetic interference coupling between the circulating pump and the heat exchange unit. After installation, two-point or three-point calibration is performed to compensate for zero-point and sensitivity errors; the calibration coefficients are stored in the controller's non-volatile memory.

[0033] The temperature controller can employ an embedded control unit with high-resolution analog-to-digital conversion and temperature linearization algorithms, with a sampling period of, for example, 100–500 ms. It calculates the error between the measured temperature near the device and the set temperature and outputs a control signal to the temperature / flow adjustable unit in the circulation path. To reduce measurement noise and suppress transient disturbances, the raw temperature data can be subjected to first- or second-order low-pass filtering at the controller end, or a hysteresis-based limiting averaging can be used. Simultaneously, it performs self-checks and alarms for sensor open circuits, short circuits, and over-limit conditions. When the ambient temperature or device power consumption changes abruptly, the controller prioritizes the temperature measurement point closest to the device as the primary control object, and corrects for errors by referring to the inlet and outlet temperature difference when necessary, achieving rapid stabilization. To prevent condensation, dew point estimation logic can be added to the low-temperature setting condition: the dew point is calculated based on the ambient temperature and humidity; when the set temperature approaches or falls below the dew point, a limiting strategy of reducing flow or increasing the liquid supply temperature is triggered, and an insulation or drying air curtain is activated.

[0034] Specifically, the temperature deviation near the device can be stabilized within ±0.1–±0.3 °C; the steady-state threshold for the inlet / outlet liquid temperature difference is used as a criterion, for example, when it is less than 0.2–0.5 °C, indicating a stable temperature field. With the help of near-field temperature measurement and real-time adjustment by the controller, the temperature of the measured area can be maintained near the set value under different environmental and power consumption conditions, reducing measurement deviations introduced by device temperature drift and improving the repeatability of cross-temperature point testing. Inlet and outlet temperature measurement can also be used as a basis for safety protection and maintenance. For example, when the temperature difference exceeds the upper limit or remains excessively large at the set flow rate, it indicates potential channel blockage or thermal interface degradation, thus allowing for early maintenance.

[0035] The temperature sensor type can be selected from platinum resistance thermometers, NTC sensors, or thermocouples based on range, insulation, and installation space. The temperature measurement points near the device can be expanded from single points to multi-point arrays. The controller uses the maximum deviation or weighted average of the multi-point data for main control and uniformity evaluation. The sensor fixing method can be changed from potting to elastic clamping or snap ring positioning for easier replacement and maintenance. Leads can be routed through microchannels within the board or rear cable trays, prioritizing locations away from high-current loops. The controller can communicate with a host computer to download set temperature curves, record and trace temperature-time data, and support power-off resume transmission and event logging. For test scenarios highly sensitive to noise, isolation drive and soft-start logic can be added to the controller output to reduce the transient impact of actuator actions on the measurement link.

[0036] Please see Figure 1-3In one possible implementation, the temperature control structure 8 is equipped with a flow actuator 10 and a temperature actuator 11, which work in a closed loop with the temperature controller. The flow actuator 10 is arranged in the circulation path between the inlet manifold 6 and the collecting manifold 7, and adjusts the flow rate or pressure difference of the coolant according to the controller's instructions. The temperature actuator 11 is connected in series in the circulation path or thermally coupled to the back of the cooling plate 3 to cool or heat the coolant to change the supply temperature. The flow actuator 10 can be a variable speed brushless magnetic pump (speed controlled by PWM or voltage, with Hall speed feedback), or a gear pump or diaphragm pump to obtain a more stable micro-flow rate. When a finer particle size is required, a proportional regulating valve or needle valve can be connected in parallel with the main pump as a fine-tuning branch. To reduce pulsation and water hammer, a small volume buffer chamber can be set on the pump outlet side, and an exhaust port can be set at the high point to remove air bubbles. The temperature actuator 11 can be a plate heat exchanger connected in series with the primary circuit (coupled to the constant temperature bath / small refrigerator through the secondary circuit), or it can be a semiconductor cooler array or thin film resistance heating element mounted on the back of the cooling plate 3; a thin layer of thermally conductive interface material is laid on both the hot and cold ends, and a flexible pre-tightening structure is used to ensure long-term stable contact pressure.

[0037] The temperature controller prioritizes the temperature measurement point closest to the device, driving the temperature actuator 11 to change the liquid supply temperature. It also drives the flow actuator 10 to rapidly increase or decrease convective heat transfer capacity, achieving a division of labor between "slow temperature measurement and fast flow measurement." The control algorithm employs PID superimposed feedforward: it outputs the main control quantity based on the error between the set temperature and the measured temperature, while using the inlet / outlet liquid temperature difference and estimated device power consumption as feedforward terms to adjust the pump speed or heat transfer capacity in advance, shortening rise / fall times. To reduce interference to the test link, the controller implements slope and amplitude limits on the pump speed and cooling power, automatically reducing the control gain within ±0.3 °C of the set value to suppress overshoot and oscillation. It performs low-pass filtering on the temperature and flow signals and sets up fault detection for sensor open circuits, short circuits, and self-heating anomalies. Once triggered, it enters a safety mode: raising the liquid supply temperature, reducing the pump speed, and triggering an alarm. When the ambient temperature is high or the set temperature is low, the controller calculates the dew point based on the ambient temperature and humidity. If the set value is lower than the dew point by a certain margin, the controller limits the maximum cooling power and flow rate, and activates the insulation or drying air curtain to prevent condensation from affecting electrical performance.

[0038] Please see Figure 1-3In one possible implementation, the flow actuator 10 is a circulating pump connected in series in the coolant circulation path upstream of the inlet manifold 6 to provide an adjustable flow rate. The circulating pump preferably has a brushless DC magnetic drive structure to isolate the transmission from the liquid chamber and reduce the risk of leakage. The material of the fluid-passing components is selected according to the working fluid: stainless steel, anodized aluminum alloy, or PPS engineering plastic. The seals are either fully statically sealed or welded. The pump is axially mounted in a low position, maintaining positive pressure between the inlet side and the replenishment / expansion chamber. A removable and washable filter is installed before the inlet to intercept impurities. To suppress pulsation and water hammer, a small-volume damping chamber is configured on the pump outlet side, and an exhaust port is located at a high point to remove free gas. The pump body is isolated from the base by an elastic vibration damping pad, and the inlet and outlet pipes use flexible pressure-resistant hoses to reduce the coupling of mechanical vibration to the test area.

[0039] Specifically, the circulation pump speed is regulated by an analog voltage or PWM signal output from the temperature controller, and the speed or flow rate signal is fed back for closed-loop control. To ensure flow accuracy, a miniature flow meter can be installed upstream of the inlet manifold 6, or the flow rate can be calculated by setting differential pressure taps on both sides of the pump and combining them with the calibrated pipeline characteristics. When an independent flow meter is not required, soft measurement is achieved using the pump's speed-flow characteristic curve and online differential pressure estimation. The control logic is set with soft start and slope limit to avoid pipeline pressure fluctuations caused by instantaneous large flow rates; a minimum sustaining flow rate is set to ensure pump body heat dissipation and lubrication. When the temperature setting is high and the heat exchange requirement is low, a low-speed circulation is maintained to prevent local stagnation and deposition.

[0040] The circulating pump, positioned upstream of the inlet manifold 6, hydraulically "push" the coolant into the parallel channels, increasing the static pressure at the inlets of each branch and reducing uneven distribution caused by minor manufacturing differences. The upstream positive pressure helps suppress cavitation and shortens system exhaust time. Combined with the aforementioned gradually increasing channel cross-section and the manifold's taper / diffusion design, a more uniform flow distribution and more consistent heat transfer flux are achieved, resulting in a more stable temperature field near the device under test. When power consumption jumps or ambient temperature disturbances occur, the pump speed is temporarily increased to enhance convective heat transfer, causing the temperature deviation in the measured area to converge rapidly. Once the set temperature is reached, the controller reduces the pump speed adjustment gain to minimize the impact of noise and vibration on the test link.

[0041] It is worth noting that a check valve and a bypass branch are installed on the pump outlet side, with a slightly open needle valve on the bypass to maintain a minimum circulation volume and pressure during maintenance; a quick connector is installed between the pump and the heat exchange unit for easy component replacement; the embedded control unit monitors speed loss, overcurrent, overtemperature, and abnormal bubbles and triggers power limiting, flow limiting, or shutdown protection; regarding compatibility with coolant, the deionized water-ethylene glycol system uses stainless steel or aluminum substrate and incorporates corrosion-inhibiting and antibacterial formulations, while the dielectric fluorinated liquid system uses inert plastic or stainless steel to avoid swelling and precipitation.

[0042] In one possible implementation, the temperature actuator 11 employs a heat exchanger connected in series with the coolant circulation path to exchange heat with the coolant. The heat exchanger is preferably a plate or microchannel structure, with its inlet and outlet directly connected to the circulation path via pressure-resistant hoses or rigid pipes. The outer wall is insulated to reduce heat exchange with the environment. The heat exchanger is coupled to the secondary loop: the secondary side is supplied with a working fluid at a controlled temperature by a constant-temperature bath or a small refrigeration / heating unit; the secondary-side pump maintains a stable flow rate; and the secondary-side temperature is maintained at a set value by an independent control loop. Temperature sampling points are arranged before and after the primary side of the heat exchanger, with the temperature of the cooling plate 3 closest to the device under test serving as the primary control variable. The controller adjusts the secondary-side refrigeration / heating power based on the deviation between the primary control variable and the set value, and, if necessary, links the primary-side flow rate to achieve a stable supply temperature.

[0043] The heat exchanger employs a counter-flow arrangement to improve the utilization rate of the logarithmic mean temperature difference and reduce primary-side temperature fluctuations. A miniature buffer chamber is added to the secondary-side inlet to suppress temperature ripple caused by compressor start-up / shutdown or heating power jumps. To reduce vibration and electromagnetic interference, the refrigeration / heating units are installed isolated from the test area, and the connecting pipelines are equipped with flexible sections and single-point grounding. During low-temperature setting, the controller estimates the dew point based on ambient temperature and humidity and applies a lower limit to the secondary-side temperature setting, while simultaneously driving a drying air curtain or external insulation layer to prevent condensation from affecting electrical performance. To improve reliability, a removable and washable filter is installed before the primary-side inlet, and exhaust ports and pressure relief valves are provided at both ends of the heat exchanger for easy start-up venting and abnormal pressure release; quick-connect couplings and check valves are used for maintenance and replacement without venting the entire circuit.

[0044] This structure enables the primary side liquid supply temperature to quickly approach the set value and maintain a small fluctuation under disturbance, thus improving the temperature stability of the tested area. The heat exchanger and secondary circuit decouple the cooling / heating process from the test area, reducing mechanical and electromagnetic coupling. The counterflow and heat preservation design improves energy efficiency and reduces temperature drift caused by changes in the external environment. The surface temperature field of the cooling plate 3 is more uniform, improving test repeatability and consistency.

[0045] It is worth noting that the heat exchanger type is selected from brazed plate type, detachable plate type, microchannel cold plate, small sleeve or coil type, depending on the target temperature range, allowable pressure drop and maintenance requirements. To shorten the primary side piping and reduce heat loss, the heat exchanger and circulating pump can be integrated into a single module. When installation space is limited, the heat exchangers can be connected in parallel as two branches, and flow distribution and redundancy can be achieved through flow balancing valves. The secondary side working fluid is selected from water-ethylene glycol, alcohol, or dielectric fluorinated fluid according to temperature range and material compatibility, and corrosion inhibitors and antibacterial formulations are added to improve stability. The control strategy adopts a cascade structure of temperature outer loop and secondary side power inner loop, and feedforward is introduced when the set temperature changes to reduce overshoot and shorten settling time. To monitor the heat exchange performance degradation, the controller periodically calculates the temperature difference and flow rate of the primary side inlet and outlet liquids to obtain the heat exchange capacity, and initiates cleaning or replacement prompts when the threshold is exceeded.

[0046] Please see Figure 1 In one possible implementation, the temperature sensor includes at least a first thermometer 12 and a second thermometer 13, which are used to detect the coolant temperature on the side entering the cooling module 4 and the coolant temperature on the side leaving the cooling module 4, respectively; the temperature controller is used to determine the temperature difference based on the detection results of the first thermometer 12 and the second thermometer 13 and use it as the basis for temperature control.

[0047] The first thermometer 12 and the second thermometer 13 can be thin-film platinum resistance temperature sensors, negative temperature coefficient thermistor temperature sensors, or thermocouple temperature sensors, installed in the thin-walled sampling section that is in direct contact with the fluid, so that the sensing end is close to the mainstream area to reduce hysteresis. Alternatively, shallow holes or temperature measuring chambers can be set in the liquid inlet manifold 6 and the liquid collector manifold 7 near the cooling module 4, and reliable thermal coupling with the coolant or cooling plate 3 can be achieved through thermally conductive potting material. The leads use shielded twisted wires and are grounded at a single point to avoid electromagnetic coupling with the circulating pump and refrigeration unit. The platinum resistance temperature sensor can use a three-wire or four-wire connection to eliminate lead resistance error. After installation, two-point or three-point calibration is performed, and the calibration coefficient is written into the temperature controller for online compensation.

[0048] The temperature controller periodically reads the temperature values ​​of the first thermometer 12 and the second thermometer 13, calculates the temperature difference, and uses it as the basis for adjustment: when the temperature difference increases and the temperature of the measured area is higher than the set value, the liquid supply temperature is reduced or the circulation flow rate is increased; when the temperature difference is too small and the temperature of the measured area is still higher than the set value, the liquid supply temperature is reduced first; when the temperature difference is often large and the target temperature has been reached, the flow rate is appropriately reduced to improve energy efficiency and reduce vibration and noise. To improve stability, the temperature controller limits and low-pass filters the two temperature signals and the temperature difference signal, and sets self-checks and alarms for exceeding limits, disconnection, and abnormal fluctuations; after the temperature field stabilizes, it automatically marks the sampling time to enter the test process. When more precise control is required, a third temperature sensor can be added to the cooling plate 3 near the device under test, using it as the main control temperature signal, and the temperature difference as an auxiliary criterion to coordinate the actions of the temperature actuator 11 and the flow actuator 10, so that the measured area is maintained near the set temperature under various environmental and power consumption conditions, and the temperature stability deviation is controlled within ±0.3 °C.

[0049] In one possible implementation, the temperature controller employs a closed-loop temperature control strategy, which is one of PID control, cascade control, or control with feedforward compensation, to maintain the temperature of the measured area at a set value.

[0050] In the PID control scheme, the temperature measurement point near the device in the measured area is used as the controlled variable, the temperature actuator 11 is the main actuator, and the flow actuator 10 is the auxiliary actuator. The temperature controller performs proportional-integral-derivative calculations on the deviation between the measured temperature and the setpoint, outputting the main control variable to the temperature actuator 11, while simultaneously adjusting the flow actuator 10 with a small gain to suppress short-term disturbances. The temperature measurement signal is filtered through primary or secondary low-pass filters, and the derivative stage uses a limited-amplitude filtered derivative to reduce the influence of measurement noise; the integral stage is configured with anti-integral saturation and amplitude limiting, and the setpoint changes in a ramp manner to suppress overshoot. The controller provides bumpless switching, allowing smooth transitions between manual, automatic, and different control modes.

[0051] In the cascade control scheme, the temperature measurement point near the device forms the outer loop, and the liquid supply temperature or circulation flow rate forms the inner loop. The outer loop calculates the deviation between the temperature of the measured area and the set value, and provides the internal setting for the liquid supply temperature or target flow rate; the inner loop tracks this internal setting with a higher bandwidth and directly drives the temperature actuator 11 or the flow actuator 10. The outer loop aims for steady-state accuracy, while the inner loop aims for fast response. Both loops are equipped with amplitude limiting and slope constraints and phase margin checks. The outer loop integrator uses conditional integration to avoid excessive accumulation during load changes.

[0052] In a control scheme with feedforward compensation, the controller estimates the heat generation power based on the power supply voltage and current of the measured AD converter, and calculates the heat transfer by combining the inlet and outlet liquid temperature difference, coolant flow rate, and specific heat. This yields a predicted value for temperature deviation, which is then superimposed on the PID or cascade control output to achieve advance compensation for power consumption steps and rapid changes in ambient temperature. The feedforward channel is configured with gain calibration and limiting to prevent oscillations caused by overcompensation; it automatically degrades to pure feedback control when the feedforward input is missing or abnormal.

[0053] All three strategies described above are used in conjunction with safety and stability mechanisms. The controller performs limit and disconnection detection on temperature, flow rate, and actuator status. When an anomaly occurs, it increases the liquid supply temperature, reduces the pump speed, and issues an alarm. It calculates the dew point based on ambient temperature and humidity; when the set value is below the dew point margin, it limits the cooling power and maximum flow rate, and simultaneously activates drying and insulation. To ensure measurement reliability, the controller sets a steady-state criterion. When the temperature deviation near the device and the inlet / outlet liquid temperature difference simultaneously meet the threshold condition and remain so for a certain period, it marks the sampling point and notifies the test module 9 to perform the measurement. Parameter tuning can employ the step response method or the closed-loop frequency domain method, and gain can be adjusted according to temperature range, flow rate, and load size to achieve consistent response quality across high, low, and medium temperature ranges.

[0054] In one possible implementation, the thermal interface material is at least one of thermal grease, phase change material, or graphite sheet.

[0055] To achieve stable thermal coupling, the cooling plate 3 and the heat dissipation side of the device under test are degreased and cleaned with anhydrous ethanol or isopropanol and dried before assembly. The flatness and roughness of the contact surface meet the requirements for low contact thermal resistance. When using thermal grease, it is applied by dispensing or scraping to form a uniform thin film, covering an area slightly larger than the chip's heat dissipation surface. After pressing, a clamping mechanism provides uniform surface pressure, ensuring that the grease only fills the microscopic gaps and eliminates air bubbles. An anti-pumping, low-volatility formula is selected to avoid interface material overflow and contamination of pins and test terminals due to prolonged thermal cycling. When using phase change material, a pre-formed sheet is cut according to the device shape. After assembly, it is held under pressure near the phase change temperature once to soften the material, wet the microscopic unevenness, and solidify it into a uniform thin layer, improving the consistency of repeated mounting and making it suitable for repeated testing at multiple temperature points and batch switching. When using graphite sheets, expandable graphite or composite graphite sheets with high in-plane thermal conductivity and moderate compressibility in the thickness direction are selected based on their anisotropic thermal conductivity. The thickness direction undergoes slight deformation under compression to conform to microscopic undulations. When the device or cold plate is exposed metal and there is a risk of electrical short circuit, a thin insulating film layer is applied to one side of the graphite sheet, or ultra-thin insulating pads are added to both sides to balance thermal conductivity and insulation. These three types of materials can be used individually or layered as needed. For example, a thin layer of phase change material can be combined with a graphite sheet to balance wettability on the upper plate and in-plane temperature uniformity, or a small amount of thermally conductive silicone grease can be applied to both sides of the graphite sheet to reduce interfacial contact thermal resistance.

[0056] During assembly, interface pressure is set using limiting structures or torque-controlled fasteners, and a short-term pressure stabilization is performed before temperature cycling to ensure full spreading of the interface material. After temperature cycling and long-term heat preservation, the interface is visually and thermally checked to confirm no pumping out, no cracking, and no warping. The surface temperature uniformity of the cold plate is compared using near-field temperature measurement or infrared thermography. If rework is required, the pre-tightening is first released, and residues are cleaned using a fiber-free wiping material and a suitable solvent. Then, the interface is rebuilt following the same process. Material selection is determined comprehensively based on temperature zone, replacement frequency, cleanliness, and electrical insulation requirements: phase change materials are preferred for high-frequency clamping to ensure reproducibility; thermally conductive silicone grease is preferred for ultra-low contact thermal resistance and high power density scenarios; graphite sheets or graphite sheets laminated with thin-layer interface materials are preferred when long-distance lateral temperature uniformity is required or when there is local hot spot transfer. To avoid condensation affecting interface stability during low-temperature testing, external insulation and a drying air curtain are used to keep the interface dry and clean under conditions below the ambient dew point.

[0057] In one possible implementation, the inlet manifold 6 and / or the collector manifold 7 are provided with tapered or diffuser sections along their length to improve the uniformity of flow distribution in the parallel cooling channels 5. The inlet manifold 6 adopts a tapered, contracting cross-section that decreases from large to small, so that the cross-sectional area decreases synchronously as the residual flow rate decreases along the flow path, thereby maintaining a nearly constant average flow velocity or static pressure gradient within the manifold. The collector manifold 7 adopts a diffuser cross-section that increases from small to large, so that the cross-sectional area increases proportionally as the number of incoming branches increases, reducing local high flow velocities and pressure drop concentrations at the outlet end. The combination of these two features can significantly reduce the static pressure difference at the inlet of each branch, resulting in a more uniform flow distribution in the parallel cooling channels 5.

[0058] In this system, the manifold length is denoted as L, and the coordinate x is measured from the inlet end. If the branches of the parallel system are equally spaced and the target flow rate of a single branch is q, then the remaining volumetric flow rate of the inlet manifold 6 at position x can be approximated as Q(x) = Q0 − n(x) · q, where Q0 is the total flow rate and n(x) is the number of branches that have been branched before x. To make the flow velocity in the manifold approximately constant at v*, A(x) = Q(x) / v is taken to obtain the area distribution of the contraction section. Similarly, the confluence flow rate of the collecting manifold 7 can be approximated as Q(x) = n(x) · q, and A(x) = Q(x) / v is taken to obtain the diffusion area distribution. In manufacturing, the width can be linearly increased while maintaining a constant cavity depth, or the width can be linearly increased while maintaining a constant width. Alternatively, a segmented multi-stage "equal arithmetic step" can be used to approximate a continuous taper to balance processing feasibility and hydraulic characteristics.

[0059] To reduce additional losses and avoid separation, the expansion angle of the diffuser section should be controlled within a small range, and the contraction angle of the contraction section should be similarly limited. The inner walls require rounded corners and smooth finishes to reduce secondary vortices and localized losses. The connections between the manifold and each parallel channel adopt a flow-through structure, with chamfered or rounded inlet edges to reduce secondary losses when entering the branches. If the system adopts a symmetrical topology with central feed or central convergence, the manifolds on both sides should have a mirrored tapered distribution, with an isobaric partition or buffer cavity at the center to further reduce static pressure deviations caused by asymmetrical layout.

[0060] During assembly, the manifold and cooling module 4 achieve a reliable seal through a planar seal or annular sealing rib. An insulation layer is added to the outer wall of the tapered section to reduce heat exchange with the environment. During startup and maintenance, free gas is discharged through an exhaust port located at the highest point of the manifold, and a washable filter is installed on the inlet side to intercept particles, preventing blockage at the narrow tapered opening. For ease of calibration and verification, pressure taps or temperature sampling points can be opened at representative locations on the manifold. Combined with known geometry and online flow data, the distribution uniformity and pressure drop model along the flow path can be verified.

[0061] When there are slight differences in the length or geometry of parallel channels, minor adjustments can be made to the local cross-sections while maintaining the overall taper / diffusion distribution to make the equivalent hydraulic resistance of each branch more consistent. If local manufacturing tolerances cause flow deviation in individual branches, small throttling vanes can be placed at their inlets for fine-tuning until the distributed flow meets the uniformity index. For high heat flux density scenarios, the target flow velocity of the taper section can be appropriately increased to enhance the convective heat transfer coefficient. For ultra-low temperature or high viscosity working fluid scenarios, priority should be given to ensuring that the pressure drop along the flow path is not too large to avoid the pump operating conditions deviating from the high-efficiency zone.

[0062] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "illustrative embodiment," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0063] Although embodiments of the present invention have been shown and described, those skilled in the art will understand that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present invention, the scope of which is defined by the claims and their equivalents.

[0064] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "illustrative embodiment," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0065] Although embodiments of the present invention have been shown and described, those skilled in the art will understand that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present invention, the scope of which is defined by the claims and their equivalents.

Claims

1. A temperature controlled AD converter testing apparatus, characterized by, include: The test fixture body is used to mount the AD converter to be tested; The cooling assembly includes a cooling plate disposed at the bottom of the test fixture body and a cooling module disposed in contact with the cooling plate. The cooling module has several cooling channels arranged in parallel inside, and the cooling channels are respectively connected to the inlet manifold and the collector manifold. The cross-section of each cooling channel gradually increases along the flow direction of the coolant. The side of the cooling plate facing the AD converter under test is a thermally conductive contact surface, and it forms a thermal coupling with the heat dissipation side of the AD converter through a thermally conductive interface material. A temperature control structure is connected to the inlet manifold and the collecting manifold to form a coolant circulation path, used to regulate the temperature and / or flow rate of the coolant to maintain a set temperature. The test module is electrically connected to the AD converter under test and is used to provide power, reference voltage and clock / excitation signal to the AD converter under test, and to acquire its output signal to complete the test.

2. The temperature controlled AD converter testing device of claim 1, wherein, The cross-sectional area of ​​each cooling channel gradually increases linearly along the flow direction of the coolant.

3. The temperature controlled AD converter testing device of claim 1, wherein, The temperature control structure includes: A temperature sensor is disposed in the region of the inlet manifold, the collecting manifold, and / or the cooling plate near the AD converter, for detecting the temperature of the measured region; A temperature controller is electrically connected to the temperature sensor and receives its detection signal. Based on the detection signal, the controller adjusts the temperature and / or flow rate of the coolant in the coolant circulation path to maintain a set temperature in the measured area.

4. The temperature-dependent AD converter testing device according to claim 3, characterized in that The temperature control structure also includes: A flow actuator, electrically connected to the temperature controller, is used to adjust the coolant flow rate and / or pressure difference in the coolant circulation path according to the control signal of the temperature controller. The flow actuator is disposed on the coolant circulation path between the inlet manifold and the collecting manifold. A temperature actuator, electrically connected to the temperature controller, is used to cool and / or heat the coolant to regulate its temperature. The temperature actuator is disposed on the coolant circulation path and / or thermally coupled to the back of the cooling plate.

5. The temperature controlled AD converter testing device of claim 4, wherein, The flow actuator is a circulating pump, which is connected in series in the coolant circulation path upstream of the inlet manifold to provide an adjustable flow rate.

6. The temperature controlled AD converter testing device of claim 4, wherein, The temperature actuator is a heat exchanger, which is connected in series with the coolant circulation path to exchange heat with the coolant.

7. The temperature controlled AD converter testing device of claim 3, wherein, The temperature sensor includes at least a first thermometer and a second thermometer, which are used to detect the coolant temperature on the side entering the cooling module and the coolant temperature on the side leaving the cooling module, respectively; the temperature controller is used to determine the temperature difference based on the detection results of the first thermometer and the second thermometer and use it as the basis for temperature control.

8. The temperature-dependent AD converter testing device according to claim 3, characterized in that The temperature controller employs a closed-loop temperature control strategy, which is one of PID control, cascade control, or control with feedforward compensation, used to maintain the temperature of the measured area at a set value.

9. The temperature controlled AD converter testing device of claim 1, wherein, The thermal interface material is at least one of thermal grease, phase change material, or graphite sheet.

10. The temperature-dependent AD converter testing device according to claim 1 or 2, characterized in that The inlet manifold and / or the collecting manifold are provided with tapered or diffuser sections along their length to improve the uniformity of flow distribution in the parallel cooling channels.

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