Wafer bonding strength test method

Abstract

The application discloses a wafer bonding strength test method, cuts a bonding wafer pair into a strip-shaped sample, adjusts a precision translation table so that a laser head is aligned with a bonding layer, scans the bonding layer of the sample by using the laser, obtains an initial crack inwards, monitors the initial crack position by using a microscope, adjusts the precision translation table according to the initial crack position, obtains a calibrated crack, sticks test pull rings on both sides of the sample after the calibration, carries out a tension test on the pull rings, obtains a load-displacement curve of the sample, calculates the bonding strength of the sample according to the load-displacement curve of the sample. The preset crack of the submicron level alignment is processed through cutting and closed-loop calibration, and then the wafer bonding strength is quantitatively tested by the DCB method, so that the problem that the bonding strength of the wafer internal position of the D2W bonding sample and the W2W bonding sample cannot be quantitatively tested is solved.

Description

Technical Field

[0001] This invention relates to a method for testing wafer bonding strength, belonging to the field of integrated circuit manufacturing technology. Background Technology

[0002] Hybrid bonding (HB) is a technique that achieves Cu interconnection (solid-state bonding) and dielectric vertical interconnection at low temperatures through plasma activation. It offers advantages such as small interconnect spacing, minimal heat-affected zones, and low-resistance interconnects. During HB process development, precise quantitative measurement of bond strength is essential to evaluate the performance of processes such as copper plating, chemical mechanical polishing, cleaning, plasma activation, and annealing, as well as the service reliability of hybrid-bonded samples.

[0003] Currently, the main methods for testing bond strength include blade insertion testing based on a double cantilever beam (DCB) structure and the Czochralski method. The blade insertion method is only suitable for wafer-to-wafer (W2W) bonding with rounded bevels, and is not applicable to die-to-wafer (D2W) or die-to-die (D2D) bonding. Furthermore, the blade insertion method cannot characterize the center bond strength of W2W bonding. When testing samples with high bond strength using the Czochralski method, it is prone to causing bulk silicon breakage, thus failing to accurately characterize the bond strength.

[0004] Another DCB testing method involves introducing pre-cracks before bonding by gold plating or laser scanning, and then applying tensile force to the upper and lower beams on both sides of the pre-cracks after bonding to induce delamination. However, the gold plating method for introducing cracks is time-consuming and costly, while the laser-induced cracking method will increase roughness, thus affecting the bonding effect. Furthermore, neither method is suitable for testing finished samples. Summary of the Invention

[0005] Objective: Currently, chip-to-wafer (D2W) bonding products are increasingly widely used and play an important role in fields such as high-performance computing chips. Because the bonding interface of D2W products lacks the aforementioned chamfered structure, bonding strength cannot be measured using traditional blade insertion methods. To overcome the shortcomings of existing technologies, this invention provides a wafer bonding strength testing method.

[0006] Technical solution: To solve the above technical problems, the technical solution adopted by the present invention is as follows:

[0007] A method for testing wafer bond strength includes the following steps:

[0008] Step 1: Cut the bonded wafers into strip-shaped samples, polish the strip-shaped samples, and obtain polished samples.

[0009] Step 2: Fix the polished sample on the fixture above the precision translation stage, and adjust the precision translation stage to align the laser head with the bonding layer.

[0010] Step 3: Use a laser to scan the bonding layer of the sample to obtain inward initial cracks.

[0011] Step 4: Monitor the initial crack position using a microscope and record the distance between the crack tip and the bonding layer on both the left and right sides of the sample. If the distance between the crack tip and the bonding layer on both the left and right sides of the sample is within the alignment accuracy threshold, proceed to Step 6. If one of the distances between the crack tip and the bonding layer on the left and right sides of the sample is greater than the alignment accuracy threshold, calculate the angle of deviation between the bonding layer and the laser processing trajectory based on the distance between the crack tip and the bonding layer on the left and right sides of the sample, and adjust the position of the sample on the precision translation stage according to the angle of deviation.

[0012] Step 5: Remove misaligned cracks by grinding and polishing. Repeat steps 3 and 4 until the distance between the crack tips and the bonding layer on both the left and right sides of the sample is within the alignment accuracy threshold.

[0013] Step 6: Attach test pull rings to both sides of the sample and perform a tensile test on the pull rings to obtain the load-displacement curve of the sample. Calculate the bond strength of the sample based on the load-displacement curve.

[0014] Optionally, the method for cutting the bonded wafer pair is one of mechanical cutting, laser stealth cutting, plasma cutting, chemical cutting, and laser-induced plasma cutting.

[0015] Optionally, the polishing method may include one of mechanical polishing, chemical mechanical polishing, and plasma polishing.

[0016] Optionally, the polishing slurry type includes one or more of silica, alumina, cerium oxide, and diamond.

[0017] Optionally, the sandpaper type includes one or more of the following: alumina sandpaper, silicon carbide sandpaper, diamond sandpaper, zirconium corundum sandpaper, and ceramic sandpaper.

[0018] Optionally, the precision translation stage includes either a manual translation stage or an automatic translation stage.

[0019] Optionally, the expression for the angle of deviation is as follows:

[0020]

[0021] in, The angle of deviation This represents the offset distance between the crack tip and the bonding layer on one side of the sample. This represents the offset distance between the crack tip and the bonding layer on the other side of the sample. This represents the width of the sample cut surface.

[0022] Optionally, step 6 includes:

[0023] Under atmospheric conditions, the test rings are driven to move by a precision tensile testing machine.

[0024] If a single DCB test is performed, the precision tensile testing machine will continue to move without resetting until the bond layers of the sample separate. The load of the precision tensile testing machine and the displacement of the bond layers after separation are recorded to obtain the load-displacement curve.

[0025] Calculate the slope of the load-displacement curve based on the load-displacement curve.

[0026] The modulus is calculated based on the slope of the load-displacement curve.

[0027] The bond strength is calculated based on the modulus and peak load.

[0028] Optionally, step 6 includes:

[0029] Step 6.1: Under atmospheric conditions, the test rings are driven to move using a precision tensile testing machine.

[0030] Step 6.2: If performing a cyclic DCB test, after the load of the precision tensile testing machine reaches its peak value, continue to displace it by a certain displacement, reset the tensile testing machine, and record the displacement of the load of the precision tensile testing machine and the bonding layer separation to obtain the load-displacement curve.

[0031] Step 6.3: Repeat step 6.2 until the samples are completely separated, and obtain several load-displacement curves.

[0032] Step 6.4: Calculate the slope of each load-displacement curve based on each load-displacement curve.

[0033] Step 6.5: Calculate the modulus corresponding to each slope based on the slope of each load-displacement curve.

[0034] Step 6.6: Calculate the bond strength for each cycle based on the modulus and peak load corresponding to each slope.

[0035] Step 6.7: Calculate the average bond strength of each cycle as the bond strength.

[0036] Optionally, the precision tensile testing machine is a constant speed displacement machine with a speed of 0.001-100 mm / min.

[0037] Beneficial effects: The wafer bonding strength testing method provided by this invention solves the technical problem that traditional blade insertion methods rely on the special chamfer structure of the wafer edge, and can only test wafer-to-wafer (W2W) bonding products, and only the edge region bonding strength of this type of product. Furthermore, it cannot measure the bonding strength in the internal region of the wafer.

[0038] The present invention provides a wafer bonding strength testing method, which uses a cutting module and a closed-loop calibration unit (including a microscope and a translation stage) to process pre-set cracks aligned at the submicron level, and then uses the DCB method to quantitatively test the wafer bonding strength, thus solving the problem that the bonding strength at the internal position of D2W bonding samples and W2W bonding samples cannot be quantitatively tested. Attached Figure Description

[0039] Figure 1 This is a schematic flowchart of a wafer bonding strength testing method according to the present invention.

[0040] Figure 2 This is a schematic diagram of wafer dicing.

[0041] Figure 3 This is a schematic diagram showing the location relationship between the crack and the bond layer obtained through laser scanning. Figure 3 (a) is a schematic diagram of the initial laser scan of the bonding layer. Figure 3 (b) is a schematic diagram of a laser crack where the crack tip does not coincide with the bonding layer. Figure 3 (c) is a schematic diagram showing the distance between the crack tips and the bonded layer on both sides of the sample as observed under a microscope. Figure 3 Image (d) is a schematic diagram of grinding to remove misaligned cracks. Figure 3 Image (e) is a schematic diagram of the laser re-scanning of the bonding layer. Figure 3 Image (f) is a schematic diagram of a laser crack with a deviation in the horizontal direction. Figure 3 (g) is a schematic diagram showing the distance between the crack tip and the bonded layer offset as observed under a microscope. Figure 3 The diagram in the middle (h) shows the removal of misaligned cracks through grinding. Figure 3 (j) is a schematic diagram of the laser re-scanning of the bonding layer. Figure 3 The diagram in (k) shows the complete alignment of the crack tip and the bonding layer.

[0042] Figure 4 This is a magnified schematic diagram showing partial views of the crack tips on both sides of the sample observed under a microscope. Figure 4 (a) is a schematic diagram of the crack tip and bonding layer on the left side. Figure 4 (b) is a schematic diagram of the crack tip and bonding layer on the right side.

[0043] Figure 5 This is a schematic diagram of the sample used for DCB testing.

[0044] Figure 6 This is a magnified schematic diagram of the crack tips on both sides in Example 2, wherein, Figure 6 (a) is a schematic diagram of the crack tip and bonding layer on the left side. Figure 6 (b) is a schematic diagram of the crack tip and bonding layer on the right side.

[0045] Figure 7 This is a schematic diagram of the DCB test process, in which... Figure 7 (a) is a schematic diagram showing the tensile forces acting on the sample from both sides. Figure 7 (b) is a schematic diagram showing the cantilever beam beginning to bend under tension. Figure 7 (c) is a schematic diagram showing that the elastic potential energy accumulated during bending of the cantilever beam exceeds the bond energy, and the bond interface is opened. Figure 7 (d) shows a diagram where the cantilever beam remains straight after the bonding interface has been opened and moved a certain distance before resetting. Figure 7 (e) is a schematic diagram showing the cantilever beam bending again when the sample is subjected to tensile force again.

[0046] Figure 8 This is a DCB load-displacement curve, where, Figure 8 (a) Schematic diagram of load-displacement curves from a single DCB test. Figure 8 (b) Schematic diagram of load-displacement curves from cyclic DCB testing. Detailed Implementation

[0047] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of the present invention.

[0048] The present invention will be further described below with reference to specific embodiments.

[0049] Example 1:

[0050] This embodiment describes a method for testing wafer bonding strength, such as... Figure 1 As shown, it includes the following steps:

[0051] Step one involves cutting the bonded wafer pair into strip-shaped samples. This facilitates testing the bonding strength at target locations on the wafer or at different locations on the wafer, thereby characterizing the overall bonding uniformity. The strip-shaped samples are then polished to ensure smooth sides and clearly visible bonding layers, resulting in the polished sample. Polishing methods include mechanical grinding, chemical mechanical grinding, and plasma polishing.

[0052] Step 2: Fix the polished sample on the fixture above the precision translation stage. Adjust the precision translation stage to change the position of the sample so that the laser head is aligned with the bonding layer.

[0053] Step 3: Use a laser to scan the bonding layer of the sample to obtain the inward initial crack.

[0054] Step four involves monitoring the initial crack location using a microscope and recording the distances between the crack tips and the bonding layer on both the left and right sides of the sample. If both distances are within the alignment accuracy threshold, proceed to step six. If either distance exceeds the alignment accuracy threshold, calculate the angle of deviation between the bonding layer and the laser processing trajectory based on the distances between the crack tips and the bonding layer on both sides. Adjust the sample position on the precision translation stage according to this angle. Microscopes include optical microscopes, scanning electron microscopes, and transmission electron microscopes.

[0055] Step 5: Remove misaligned cracks by grinding and polishing. Repeat steps 3 and 4 until the distance between the crack tips and the bonding layer on both the left and right sides is within the alignment accuracy threshold.

[0056] Step Six: Attach test pull rings to both sides of the sample with the standard test crack. Perform a tensile test on the sample with pull rings using a precision tensile testing machine under atmospheres of air, high-purity nitrogen, or high-purity argon. The tensile testing machine is in constant-speed displacement mode, with a displacement speed of 0.001-100 mm / min. Each time the load in the test curve reaches its peak, continue displacement for a certain distance, then reset the tensile testing machine to obtain a load-displacement curve. Repeat the tensile test until the sample completely separates. Several load-displacement curves are obtained. Process the curve data and obtain the modulus based on the curve slope. Calculate the bond strength based on the modulus and peak load. Take the average bond strength of the last few load-displacement curves to characterize the bond strength of the sample.

[0057] Furthermore, step one includes:

[0058] Step 101: Cut the bonded wafer pair into strip-shaped samples (hereinafter referred to as samples). The length and width of the samples are both less than 300 mm, and the thickness is less than 3 mm. Figure 2 As shown, the bonding wafer pair consisting of two wafers 1 is cut by a cutting blade 4.

[0059] Step 102: Polish the cut surface of the sample.

[0060] Furthermore, in step 101, the method for cutting the bonded wafer pair is one of mechanical cutting, laser stealth cutting, plasma cutting, chemical cutting, or laser-induced plasma cutting.

[0061] Furthermore, in step 102, the polishing methods include mechanical polishing, chemical mechanical polishing, and plasma polishing.

[0062] Furthermore, in step 102, the polishing slurry used includes one or more materials such as silicon dioxide, aluminum oxide, cerium oxide, and diamond.

[0063] Furthermore, in step 102, the type of sandpaper used includes one or more of alumina sandpaper, silicon carbide sandpaper, diamond sandpaper, zirconium corundum sandpaper, and ceramic sandpaper.

[0064] Furthermore, in step two, the precision translation stage used is either a manual translation stage or an automatic translation stage.

[0065] Furthermore, in step three, such as Figure 3 As shown in (a), it includes:

[0066] Step 301: Using the cutting laser 7 of a laser cutting, plasma cutting, chemical cutting, or stealth laser cutting machine, laser-introduced cracks 3 are processed at the bonding layer 2.

[0067] Furthermore, in step four, the following is included:

[0068] Step 401: Measure the offset distance between the crack tips and the bonded layer on both sides of the sample using one of an optical microscope, electron microscope, or X-ray microscope, and calculate the sample offset angle accordingly. Figure 3 As shown in (b), the formula for calculating the sample offset angle is as follows:

[0069]

[0070] in, The sample offset angle, This represents the offset distance between the crack tip and the bonding layer on one side of the sample. This represents the offset distance between the crack tip and the bonding layer on the other side of the sample. This represents the width of the sample cut surface.

[0071] Step 402: Adjust the angle of the precision translation stage according to the sample offset angle, such as... Figure 3 As shown in (c).

[0072] Furthermore, in step five, the following is included:

[0073] Step 501: Remove misaligned cracks, reprocess the cracks, repeat the offset distance measured in Step 4, and adjust the horizontal position of the precision translation stage, such as... Figure 3 As shown in (d), (e), and (f).

[0074] Step 502: Repeat step three, as follows Figure 3 As shown in (g), (j), and (k), the final sample with standard test crack 9 was obtained, and its specific structure is as follows. Figure 4 As shown.

[0075] Furthermore, step six includes:

[0076] Step 601: Attach the test pull ring 10 to the periphery of the sample crack, as shown in the sample... Figure 5 As shown.

[0077] Step 602: Under an atmosphere of air, high-purity nitrogen, or high-purity argon, test the sample with the pull ring from Step 601 using a precision tensile testing machine. The tensile testing machine is in constant-speed displacement mode, with a displacement speed of 0.001-100 mm / min. Each time the load in the test curve reaches its peak, continue displacement for a certain distance, then reset the tensile testing machine to obtain a load-displacement curve.

[0078] Step 603: Repeat step 602 until the samples are completely separated. Several load-displacement curves are then obtained. The load-displacement curve data are processed, and the slope of each curve is fitted to obtain the modulus. The bond strength is then calculated based on the modulus and peak load.

[0079] Example 2:

[0080] This embodiment provides an example of a wafer bonding strength testing method, including the following steps:

[0081] Step 1: Cut the bonded wafers into strip-shaped samples and polish them.

[0082] Step one includes:

[0083] 11) Cut the bonded wafer pair into 5x40 mm samples.

[0084] The method for cutting bonded wafer pairs is one of mechanical cutting, laser stealth cutting, plasma cutting, chemical cutting, or laser-induced plasma cutting.

[0085] 12) Polish the cut surface of the sample, with the final polishing direction perpendicular to the bonding layer.

[0086] Polishing methods include mechanical polishing, chemical mechanical polishing, and plasma polishing;

[0087] The polishing slurry used includes one or more of the following: silica-based, alumina-based, cerium oxide-based, and diamond-based.

[0088] The types of sandpaper used include one or more of the following: alumina sandpaper, silicon carbide sandpaper, diamond sandpaper, zirconium corundum sandpaper, and ceramic sandpaper.

[0089] Step two involves monitoring the crack location using a microscope and adjusting the sample position using a precision translation stage to initially locate the bonding interface of the sample to be processed.

[0090] The precision translation stage used is either a manual translation stage or an automatic translation stage.

[0091] In this embodiment, the precision translation stage used is a manual translation stage, with a translation step accuracy of better than 1mm in the XYZ direction and a rotation accuracy of better than 5′ in the R direction.

[0092] Step 3: Machining an inward initial crack at the bonding interface. Adjusting the precision translation stage according to the offset of the initial crack and the bonding layer to achieve high-precision alignment between the crack machining position and the bonding interface, with an alignment accuracy better than 1 mm.

[0093] Step four includes:

[0094] 41) Using laser cutting, plasma cutting, chemical cutting, or stealth laser cutting machines, initial cracks are machined at the bonding layer to precisely induce cracking at the bonding interface.

[0095] In this embodiment, the laser cutting machine is a YAG laser cutting machine, and the cutting parameters are: speed 10 mm / s, current 2 A, frequency 20 kHz, and pulse width 40 μs.

[0096] 42) Use one of the following methods—optical microscope, electron microscope, or X-ray microscope—to measure the offset distance between the crack tips and the bonded layer on both sides of the sample in step two, and calculate the sample offset angle accordingly. Figure 6 As shown in (a) and (b), the offset distances between the crack tips and the bonding layer on both sides are 10 μm and 6 μm, respectively. Combined with the fact that the width of the sample at this time is about 4900 μm, the sample offset angle is about 0.187°.

[0097] 43) Adjust the angle of the precision translation stage according to the sample offset angle.

[0098] 44) Remove misaligned cracks by sanding, and then process the cracks again using a laser.

[0099] 45) Adjust the horizontal position of the precision translation stage according to the offset distance measured in step 44).

[0100] Step 5: Remove misaligned cracks by sanding, and then perform a second laser scan on the bonding layer of the sample to produce standard test cracks.

[0101] Step 6: Conduct a double cantilever beam test based on the calibrated crack, and calculate the bond strength G using the load-displacement curve. c .

[0102] Step six includes:

[0103] 61) Attach a test pull ring to the periphery of the sample crack.

[0104] 62) The sample with the pull ring from step 61) is tested using a precision tensile testing machine under an atmosphere of air, high-purity nitrogen, or high-purity argon. The tensile testing machine is in constant velocity displacement mode, with a displacement speed of 0.001-100 mm / min.

[0105] To accurately calculate bond strength, a cyclic DCB test should be performed if a single DCB test is conducted, where the push-pull tester continues to move without resetting. Figure 7 As shown in (a) to (e), after the load in the test curve reaches its peak value, the displacement continues for a certain distance, and the tensile testing machine is reset, resulting in a load-displacement curve, as follows. Figure 8 (a) shows the load-displacement curve. This curve can be divided into three segments: a, b, and c. In segment a, the cantilever beam bends, accumulating elastic potential energy, and the load increases linearly. In segment b, the energy accumulated during the bending of the cantilever beam exceeds the interfacial bonding energy, the crack begins to propagate, and the load begins to decrease. In segment c, the crack propagation rate and the push-pull force gauge test rate reach a relative equilibrium. Usually, the bond strength is calculated using the curve in segment c, where the crack propagates stably.

[0106] Repeat the above process until the samples are completely separated, at which point several load-displacement curves are obtained, such as... Figure 8 As shown in (b).

[0107] The curve data is processed, and the slope of the curve yields the modulus. The bond strength is calculated based on the modulus and peak load, and the average bond strength of the last load-displacement curve is used to characterize the bond strength of the sample.

[0108] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A method for testing wafer bonding strength, characterized in that: Includes the following steps: Step 1: Cut the bonded wafers into strip-shaped samples, polish the strip-shaped samples, and obtain polished samples; Step 2: Fix the polished sample on the fixture above the precision translation stage, and adjust the precision translation stage to align the laser head with the bonding layer; Step 3: Use a laser to scan the bonding layer of the sample to obtain the inward initial crack; Step 4: Monitor the initial crack position using a microscope and record the distance between the crack tip and the bonding layer on the left and right sides of the sample. If the distance between the crack tip and the bonding layer on the left and right sides of the sample is within the alignment accuracy threshold, proceed to step six. If one of the distances between the crack tip and the bonding layer on the left and right sides of the sample is greater than the alignment accuracy threshold, calculate the angle of deviation between the bonding layer and the laser processing trajectory based on the distance between the crack tip and the bonding layer on the left and right sides of the sample, and adjust the position of the sample on the precision translation stage according to the angle of deviation. Step 5: Remove misaligned cracks by grinding and polishing. Repeat steps 3 and 4 until the distance between the crack tips and the bonding layer on both the left and right sides of the sample is within the alignment accuracy threshold. Step 6: Attach test pull rings to both sides of the sample, perform a tensile test on the pull rings, obtain the load-displacement curve of the sample, and calculate the bond strength of the sample based on the load-displacement curve. The expression for the angle of the deviation is as follows: ； in, The angle of deviation This represents the offset distance between the crack tip and the bonding layer on one side of the sample. This represents the offset distance between the crack tip and the bonding layer on the other side of the sample. This represents the width of the sample cut surface.

2. The wafer bonding strength testing method according to claim 1, characterized in that: The method for cutting bonded wafer pairs is one of mechanical cutting, laser stealth cutting, plasma cutting, chemical cutting, and laser-induced plasma cutting.

3. The wafer bonding strength testing method according to claim 1, characterized in that: Polishing methods include one of mechanical polishing, chemical mechanical polishing, and plasma polishing.

4. The wafer bonding strength testing method according to claim 1, characterized in that: The polishing fluid used during polishing includes one or more of the following: silica, alumina, cerium oxide, and diamond.

5. The wafer bonding strength testing method according to claim 1, characterized in that: The types of sandpaper used for polishing include one or more of the following: alumina sandpaper, silicon carbide sandpaper, diamond sandpaper, zirconium corundum sandpaper, and ceramic sandpaper.

6. The wafer bonding strength testing method according to claim 1, characterized in that: Precision translation stages include either manual translation stages or automatic translation stages.

7. The wafer bonding strength testing method according to claim 1, characterized in that: Step 6 includes: Under atmospheric conditions, a precision tensile testing machine was used to drive the test rings to move. If a single DCB test is performed, the precision tensile testing machine will not reset and will continue to move until the bond layer of the sample separates. The load of the precision tensile testing machine and the displacement of the bond layer separation are recorded to obtain the load-displacement curve. Calculate the slope of the load-displacement curve based on the load-displacement curve. The modulus is calculated based on the slope of the load-displacement curve; The bond strength is calculated based on the modulus and peak load.

8. The wafer bonding strength testing method according to claim 1, characterized in that: Step 6 includes: Step 6.1: Under atmospheric conditions, drive the test rings to move using a precision tensile testing machine; Step 6.2: If performing a cyclic DCB test, after the load of the precision tensile testing machine reaches its peak value, continue to displace it by a certain displacement, reset the tensile testing machine, record the load of the precision tensile testing machine and the displacement at which the bond layer separates, and obtain the load-displacement curve; Step 6.3: Repeat step 6.2 until the samples are completely separated, and obtain several load-displacement curves; Step 6.4: Calculate the slope of each load-displacement curve based on each load-displacement curve; Step 6.5: Calculate the modulus corresponding to each slope based on the slope of each load-displacement curve; Step 6.6: Calculate the bond strength for each cycle based on the modulus and peak load corresponding to each slope; Step 6.7: Calculate the average bond strength of each cycle as the bond strength.

9. A wafer bonding strength testing method according to claim 7 or 8, characterized in that: The precision tensile testing machine is a constant speed displacement machine with a speed of 0.001-100 mm / min.

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