High-acceleration temperature shock reliability testing device for sample

Abstract

The utility model belongs to the technical field of testing equipment, and particularly relates to a high-acceleration temperature shock reliability testing device for a sample, which comprises a sample cabin, a sample placing frame, a cooler and / or a heater, the sample cabin is of a sealed heat-insulating hollow structure, and an opening capable of introducing fluid into an inner cavity of the sample cabin is formed in the sample cabin; the plurality of sample racks are uniformly distributed in the inner cavity of the sample cabin, and the top ends of the sample racks are provided with insertion openings for insertion of samples; and a plurality of coolers and / or heaters are uniformly distributed in the inner cavity of the sample cabin. According to the high-acceleration temperature shock reliability testing device for the sample, through mutual cooperation of the sample cabin, the sample placing frame, the cooler and / or the heater, the testing environment can be flexibly adjusted according to testing requirements, meanwhile, the uniformity of fluid in the testing environment is guaranteed, continuous detection can be achieved, the testing efficiency and the testing precision are greatly improved, and the testing cost is reduced. And the test cost is reduced.

Description

Technical Field

[0001] This utility model relates to the field of testing device technology, specifically to a high-accelerated temperature shock reliability testing device for samples, used for high-accelerated temperature shock reliability testing (HATS) of electronic components such as printed circuit boards, substrates, and solder joints. Background Technology

[0002] Temperature shock testing has long been a recognized method for verifying the reliability of plated through-holes and solder joints in electronic components. For solder joints on printed circuit boards, the reliability acceleration mechanism is the function of the coefficient of thermal expansion of the materials used in the device under test (DUT). This coefficient determines the stress introduced into the DUT and the resulting reliability acceleration due to the difference between extreme temperatures in the test environment.

[0003] Temperature shock conditions are created by rapidly moving the device under test (DUT) between two extreme temperatures, typically requiring a transition time of less than 5 minutes between the extreme temperatures. Typically, the DUT includes a "test board," or a separate test board is used, and its electrical characteristics, such as resistance, are monitored. The test board contains standard components, such as vias in various layouts, and its connection to the test system is determined by the specific system. Therefore, it is actually the test board, not the DUT, that is being tested. Since the test board and the DUT are manufactured using the same process and (optionally) at the same time, the reliability of the test board can be a good indicator of the reliability of the DUT.

[0004] Typically, the extreme low temperatures range from -40°C to -65°C, and the extreme high temperatures range from 85°C to 265°C. The time the device under test (DUT) must remain at these extreme temperatures before reaching equilibrium, also known as the dwell time, varies from a few minutes to an hour. This dwell time depends on the method used to generate the extreme temperatures, the thermal conductivity, and the mass of the DUT. For example, for large components weighing over 136 kg, the dwell time might reach 8 hours. This time is necessary because typical testing methods do not directly measure the temperature of the DUT sample; instead, they require estimating the time needed for the DUT to reach equilibrium at the desired temperature. Since a complete test consists of tens to thousands of cycles, this equilibrium time is crucial.

[0005] In the past, the two most common methods for generating temperature shock environments were air-to-air and liquid-to-liquid methods. Traditional air-to-air temperature shock systems use two separate chambers, each set to opposite extreme temperatures, and a mechanism to move the device under test (DUT) between the two chambers. While these chambers are readily available, they are expensive to operate and have low heat exchange rates on the DUT. Liquid-to-liquid methods also use two chambers, each set to opposite extreme temperatures, utilizing a special liquid and a mechanism to move the DUT between the two liquids. Unlike the chambers in air-to-air methods, this expensive liquid provides excellent heat exchange rates, thus enabling rapid movement of the DUT between extreme temperatures. Because both methods involve actual movement of the DUT, the cables connected to the DUT must be movable.

[0006] The reliability of the device under test (DUT) is determined by monitoring the resistance of the sample during testing. When the sample fails, the resistance changes, providing reliability data. The aforementioned test systems all require moving the sample, making electrical measurements difficult during cycles. Furthermore, the long cables typically limit high-precision measurements, and the number of data points that can be monitored is also restricted. This low-frequency monitoring also means that monitoring conditions causing fluctuations, or even the actual point of failure, may be overlooked.

[0007] Another temperature shock system is the Interconnect Stress Testing (IST) system, disclosed in several U.S. patents by Birch et al., patent numbers: 5,392,219, 5,451,885, and 5,701,667. This method integrates a copper circuit (including wires and vias) into the device under test (DUT) as a resistance heating element, which is then cooled to ambient temperature using circulating air. The advantage of this method is that the current required to raise the sample to the desired temperature can be predetermined, eliminating the need for dwell time during actual testing. However, this technique also has several drawbacks. The current required to heat the sample to the desired temperature is not empirically determined but calculated based on the sample's resistance at room temperature. Furthermore, if the sample fails during testing, the system resistance changes, thus requiring modification of the applied current to maintain the desired temperature. Unfortunately, determining the appropriate new current value is theoretically feasible but practically difficult, leading to insufficient control. For example, for a particular DUT, the upper limit temperature may exceed its maximum required temperature, which is determined by the physicochemical transition temperature (Tg) of certain materials in the DUT or test board. Furthermore, this method does not include the cooling portion of the temperature cycling, so it cannot replicate the traditional temperature shock test in terms of either low-temperature extension or overall temperature range.

[0008] Therefore, there is a need for a temperature shock / cycling test system that can accurately determine the sample temperature, eliminate dwell time, perform temperature monitoring without using the sample's electrical characteristics, continuously monitor the sample, and perform temperature cycling in extreme temperature ranges above and below ambient temperature without moving the sample. Utility Model Content

[0009] To address the shortcomings of existing technologies, this invention provides a high-acceleration temperature shock reliability testing device for samples, which greatly improves testing time and reliability and significantly reduces development costs.

[0010] This utility model is achieved through the following technical solution:

[0011] This utility model provides a high-acceleration temperature shock reliability testing device for samples, including a sample chamber, a sample holder, a cooler and / or a heater;

[0012] The sample chamber is a sealed, insulated, hollow structure, and has an opening inside the sample chamber that allows fluid to be introduced into the inner cavity of the sample chamber.

[0013] The sample holder has multiple components, which are evenly distributed in the inner cavity of the sample chamber, and the top of the sample holder has an insertion port for inserting samples.

[0014] The cooler and / or heater are multiple and are evenly distributed within the sample chamber.

[0015] To ensure airtightness and facilitate the disassembly and assembly of components inside the sample chamber, the sample chamber includes a cylindrical chamber body and a cover that fits over the top of the cylindrical chamber body. The inner walls of the cylindrical chamber body and the cover have a heat insulation layer.

[0016] To ensure uniform airflow inside the sample chamber, the opening is located at the bottom center.

[0017] To ensure that the spacing between adjacent sample holders is the same and to allow for uniform fluid flow, thereby improving detection accuracy, the sample holders are located at the bottom of the sample chamber and are evenly distributed in a ring around the opening.

[0018] Similarly, in order to ensure the uniformity of heating or cooling, the cooler and / or heater are located at the bottom of the sample chamber and are evenly distributed in a ring between the opening and the sample holder.

[0019] Furthermore, to ensure uniform fluid distribution, each sample holder is equidistant from the cooler and / or heater.

[0020] In order to accommodate one or more different types of samples, the top of the sample holder has several sets of slots for accommodating different samples, and one or more samples can be accommodated on one sample holder.

[0021] To facilitate the disassembly, assembly, and maintenance of the sample holder, the sample holder and the sample chamber are detachably connected by screws.

[0022] The beneficial effects of this utility model are: the high-acceleration temperature shock reliability testing device for samples, through the cooperation of the sample chamber, sample rack, cooler and / or heater, can flexibly adjust the test environment according to the test requirements, while ensuring the uniformity of the fluid in the test environment, and can realize continuous detection, which greatly improves the test efficiency and test accuracy, and reduces the test cost. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of the external structure of the high-acceleration temperature shock reliability testing device for samples according to this utility model.

[0024] Figure 2 This is a schematic diagram of the internal structure of the high-acceleration temperature shock reliability testing device for samples according to this utility model. Detailed Implementation

[0025] The preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings, so that the advantages and features of the present invention can be more easily understood by those skilled in the art, thereby providing a clearer and more definite definition of the scope of protection of the present invention.

[0026] like Figure 1 , Figure 2 The apparatus shown is a high-acceleration temperature shock reliability test device for samples, including a sample chamber, a sample holder 3, a cooler and / or a heater 6.

[0027] Specifically, the sample chamber is a sealed, insulated, hollow structure. The sample chamber includes a cylindrical chamber 1 and a cover 2 that covers the top of the cylindrical chamber 1. The inner walls of the cylindrical chamber 1 and the cover 2 have an insulation layer. The cylindrical chamber 1 of the sample chamber has an opening 5 that can introduce fluid into the inner cavity of the sample chamber. The opening 5 is located at the bottom center of the cylindrical chamber 1.

[0028] Specifically, there are multiple sample holders 3, which are located at the bottom of the cylindrical chamber 1 of the sample compartment and are evenly distributed in a ring around the opening 5. The sample holders 3 are detachably connected to the cylindrical chamber 1 by screws 8. The top of the sample holder 3 has several sets of insertion slots 7 for inserting different samples, and one or more samples 4 can be inserted into one sample holder 3. It should be noted that the sample holders 3 are connected to the data acquisition system.

[0029] Specifically, there are multiple coolers and / or heaters 6, which are disposed at the bottom of the cylindrical chamber 1 of the sample compartment and are evenly distributed in a ring between the opening 5 and the sample rack 7. Each sample rack 7 is equidistant from the cooler and / or heater 6, and each cooler and / or heater 6 is equidistant from the opening 5. It should be noted that, depending on the actual situation, this invention may include only coolers, only heaters, or both in the sample compartment, and their quantity may be adjusted according to the actual situation. The coolers and heaters are connected to the data acquisition system.

[0030] In this invention, "sample" or "device under test (DUT)" refers to any device, electronic component, printed circuit board (PCB), printed circuit board (PWB), plated through-hole (PTH), interconnect structure, mesh, via, solder joint and test board, or any other item or component that needs to be thermally reliable tested.

[0031] In this invention, "fluid" refers to liquids, vapors, air, gases, inert gases, etc. For rapid temperature circulation within the desired temperature range, proper sample placement in the equipment is crucial to ensure unobstructed and uniform flow of the cooling or heating fluid across all samples. The sample chamber of this invention has an opening 5 through which the cooling or heating fluid, preferably air, is introduced. The air is preferably dried by a dryer to remove moisture, and then preferably compressed by a two-stage compressor. The compressed, dried air is then preferably cooled to approximately -90°C and then heated by a high-power heater to any target temperature required at any time during testing. Alternatively, the air can be precisely cooled to target temperatures below ambient temperature and separately and precisely heated to target temperatures above ambient temperature. Any method can be used to cool or heat the fluid.

[0032] Sample 4 can be selected using an IPCD test board and / or HATS. 2 A daisy-chain / single-well test plate is placed on the sample holder 3, preferably along the circumference of the opening 5. The samples 4 are preferably evenly spaced and equidistant from the opening 5. For this type of device under test, or other similarly shaped devices, it is important that the orientation of the samples 4 relative to the opening 5 ensures unobstructed fluid flow. In a preferred embodiment, the samples 4 are mounted radially outward within the sample chamber relative to the fluid opening 5. This mounting orientation and uniform spacing ensure that all samples 4 are cooled or heated uniformly and as quickly as possible, maximizing the number of samples that can be accommodated in the sample chamber and making it possible to heat and cool using a single sample chamber.

[0033] The sample holder 3 has an electrical contact in its socket 7 for electrically connecting the sample 4 to a device used to measure its electrical characteristics. The resistance of multiple samples on each sample holder 3 is measured by a precision ohmmeter or equivalent device using the Kelvin four-wire method, and the measured resistance results are transmitted to a computer or processor for data acquisition and analysis.

[0034] According to this invention, any type of test board can be used, whether standalone or integrated into the device under test. For example, a test board for studying solder joints may include multiple chip packages or similar devices attached to one or both sides of a printed circuit board. A daisy-chain / single-hole network of solder joint connections is formed by the connection between the circuit board and the chip packages, and the state of the solder joint is monitored by a precision resistor in each daisy-chain / single-hole network.

[0035] Temperature shock testing involves rapidly cycling the device under test (DUT) from a minimum temperature to a maximum temperature, and then back to the minimum temperature. If the cycle time is insufficient, the components within the DUT will not be able to reach equilibrium at the required extreme temperatures, thus failing to achieve the desired temperature change ΔT. Conversely, if the cycle time is long enough that, conservatively estimated, the DUT has stabilized at the required extreme temperature, the test duration becomes undesirable. Therefore, to obtain the correct temperature change ΔT within the shortest possible cycle time, it is crucial to know whether the DUT has reached either of the required extreme temperatures. During temperature cycling, the measured resistance of each grid changes with the failure of various components (such as vias). Therefore, it is important not to determine the cycle parameters based on the electrical characteristics of the sample when testing it.

[0036] The test method of the high-acceleration temperature shock reliability testing device for samples of this utility model includes the following steps: changing the temperature of the sample until the temperature stabilizes at a desired temperature, and measuring the stable resistance of the sample at the desired temperature; determining the duration for which the sample reaches the stable resistance associated with the desired temperature; changing the temperature of one or more samples during the duration to reach the desired temperature; there are at least two desired temperatures, both of which are temperature-changed, and preferably, after the temperature-changing steps at at least two desired temperatures, the above determination steps are performed for each desired temperature; the duration for reaching the stable resistance associated with the desired temperature is preferably measured starting when the resistance of the sample is a stable resistance value associated with another different desired temperature, and the temperature-changing steps are preferably repeated alternately between at least two desired temperatures; the determination steps are preferably repeated multiple times until at least two time values ​​for the time when the sample reaches the stable resistance associated with the desired temperature are measured, and both time values ​​are within a predetermined error range; the determination steps are preferably repeated multiple times until at least two measurements of the stable resistance at the desired temperature are within the predetermined error range.

[0037] The embodiments described above merely illustrate the implementation of this utility model, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the utility model patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this utility model, and these modifications and improvements all fall within the protection scope of this utility model.

Claims

1. A high-acceleration temperature shock reliability testing device for samples, characterized in that: Includes sample chamber, sample rack, cooler and / or heater; The sample chamber is a sealed, insulated, hollow structure, and has an opening inside the sample chamber that allows fluid to be introduced into the inner cavity of the sample chamber. The sample holder has multiple components, which are evenly distributed in the inner cavity of the sample chamber, and the top of the sample holder has an insertion port for inserting samples. The cooler and / or heater are multiple and are evenly distributed within the sample chamber.

2. The high-acceleration temperature shock reliability testing device for samples according to claim 1, characterized in that: The sample chamber includes a cylindrical chamber body and a cover that fits over the top of the cylindrical chamber body. The inner walls of the cylindrical chamber body and the cover have a heat insulation layer.

3. The high-acceleration temperature shock reliability testing device for samples according to claim 2, characterized in that: The opening is located at the bottom center of the sample chamber.

4. The high-acceleration temperature shock reliability testing device for samples according to claim 3, characterized in that: The sample holder is located at the bottom of the sample chamber and is evenly distributed in a circular shape around the opening.

5. The high-acceleration temperature shock reliability testing device for samples according to claim 4, characterized in that: The cooler and / or heater are located at the bottom of the sample chamber and are evenly distributed in a ring shape between the opening and the sample holder.

6. The high-acceleration temperature shock reliability testing apparatus for samples according to claim 5, characterized in that: Each sample rack is equidistant from the cooler and / or heater.

7. The high-acceleration temperature shock reliability testing apparatus for samples according to claim 5, characterized in that: The top of the sample holder has several sets of slots for inserting different samples, and one or more samples can be inserted into one sample holder.

8. The high-acceleration temperature shock reliability testing apparatus for samples according to claim 5, characterized in that: The sample holder and the sample chamber are detachably connected by screws.

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