Detection method of intermetallic compound

Abstract

The invention provides a detection method of an intermetallic compound, and relates to the technical field of material detection. The detection method of the intermetallic compound comprises the following steps: heating a to-be-detected sample to enable the intermetallic compound in the to-be-detected sample to fully grow; the heated to-be-detected sample is put into corrosive liquid to be corroded until intermetallic compounds are exposed, and the temperature of the corrosive liquid ranges from 50 DEG C to 80 DEG C; and acquiring a growth plane graph of the intermetallic compound by adopting a scanning electron microscope. The detection method comprises the following steps: heating a sample to be detected, simulating the actual welding temperature of a solder ball, enabling an intermetallic compound to fully grow, enabling the growth condition to be close to the growth condition of the intermetallic compound in the actual welding process, quickly corroding the solder ball by using a corrosive liquid at 50-80 DEG C, enabling the intermetallic compound to be fully exposed, and finally detecting the welding temperature of the solder ball. And finally, acquiring a growth plane graph of the intermetallic compound by using a scanning electron microscope. Therefore, the growth condition of the intermetallic compound can be obtained more comprehensively, accurately and quickly.

Description

Technical Field

[0001] This application relates to the field of materials testing technology, and more specifically, to a method for detecting intermetallic compounds. Background Technology

[0002] In microelectronic packaging, solder balls are the "nerve center" and "mechanical pillar" connecting chips to substrates and components to PCBs. As electronic products become smaller and denser, the size of solder joints is decreasing dramatically, and the volume proportion of intermetallic compound (IMC) phases inside them is increasing significantly. Sometimes, excessive growth of IMC can lead to problems such as poor soldering, cold solder joints, and cracks after soldering.

[0003] Because the physical properties (such as electrical conductivity and thermal conductivity), mechanical properties (such as hardness, elastic modulus, and fracture toughness), and thermal fatigue properties of intermetallic compounds directly determine the reliability of micro-solder joints, data analysis of intermetallic compounds is necessary to assess the reliability of micro-solder joints. Currently, laboratory analyses of intermetallic compounds typically involve observing the growth of intermetallic compounds in cross-sections using slicing methods. The resulting data is often one-sided and inaccurate. Summary of the Invention

[0004] The purpose of this application is to provide a method for detecting intermetallic compounds (IMCs) that addresses the shortcomings of the prior art, enabling more comprehensive and accurate acquisition of IMC growth data.

[0005] To achieve the above objectives, the technical solutions adopted in the embodiments of this application are as follows: This application provides a method for detecting intermetallic compounds, including: The sample to be tested is heated to allow the intermetallic compound in the sample to grow sufficiently. The sample to be tested is a chip with solder balls. The heated sample to be tested is placed in an etching solution for etching until the intermetallic compounds are exposed. The temperature of the etching solution is 50°~80°. A planar image of the growth of intermetallic compounds was obtained using a scanning electron microscope.

[0006] Optionally, before obtaining a growth planar image of the intermetallic compound using a scanning electron microscope, the detection method further includes: Remove the complexes that form on the tin balls after etching.

[0007] Optionally, removing the complexes formed on the etched solder balls includes: The sample to be tested is immersed in a mixture of ammonia and hydrogen peroxide to remove the complex formed on the tin balls after etching.

[0008] Optionally, the corrosive solution is hydrochloric acid with a concentration of 25% to 30%.

[0009] Optionally, the heated sample to be tested is immersed in an etching solution for etching, which includes: The heated sample is placed in an etching solution for etching, and the sample is removed at preset time intervals to observe the exposure of intermetallic compounds on the tin balls. The preset time intervals are gradually shortened.

[0010] Optionally, heating the sample to be tested includes: The sample to be tested is placed in a heating furnace and baked at a temperature of 50°~80°.

[0011] Optionally, after removing the complexes formed on the etched solder balls, the detection method further includes: The sample to be tested was immersed in deionized water and then rinsed with acetone. Dry the rinsed sample.

[0012] Optionally, before obtaining a growth planar image of the intermetallic compound using a scanning electron microscope, the detection method further includes: Electroplating a conductive layer onto the exposed intermetallic compound surface.

[0013] Alternatively, the corrosion solution can be heated by a water bath during the corrosion process.

[0014] Optionally, the heated sample to be tested is immersed in an etching solution for etching, which includes: The heated sample is placed in the etching solution with the solder balls facing upwards for etching. Immersing the sample in a mixture of ammonia and hydrogen peroxide includes: Immerse the sample with the solder balls facing down in a mixture of ammonia and hydrogen peroxide. The sample to be tested is immersed in deionized water and then rinsed with acetone, including: Immerse the sample with the solder balls facing upwards in deionized water and then rinse with acetone. Drying the rinsed sample to be tested includes: Dry the sample with the solder balls facing upwards after rinsing.

[0015] The beneficial effects of this application include: This application provides a method for detecting intermetallic compounds, comprising: heating a sample to be tested to allow the intermetallic compound to grow sufficiently, wherein the sample to be tested is a chip with solder balls; immersing the heated sample to be tested in an etching solution until the intermetallic compound is exposed, wherein the temperature of the etching solution is 50°C to 80°C; and acquiring a growth planar image of the intermetallic compound using a scanning electron microscope. This method first heats the sample to be tested to simulate the actual soldering temperature of the solder balls, allowing the intermetallic compound to grow sufficiently, and the growth pattern is similar to that of the intermetallic compound during actual soldering. Then, the solder balls are rapidly etched using an etching solution at 50°C to 80°C, allowing the intermetallic compound to be fully exposed without damaging it. Finally, the growth of the intermetallic compound is observed using a scanning electron microscope to acquire a growth planar image of the intermetallic compound, which can more comprehensively record the growth data of the intermetallic compound. Therefore, compared with the prior art, this method for detecting intermetallic compounds can more comprehensively, accurately, and quickly obtain information on the growth of the intermetallic compound. Attached Figure Description

[0016] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this application and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1 One of the flowcharts for the detection method of intermetallic compounds provided in the embodiments of this application; Figure 2 A planar view of the growth of an intermetallic compound obtained by scanning electron microscopy when a platinum layer is electroplated on the surface of the intermetallic compound as a conductive layer. Figure 3 The second flowchart of the method for detecting intermetallic compounds provided in the embodiments of this application; Figure 4 This is an image of the sample under test observed using an optical microscope. Figure 5 The third flowchart of the method for detecting intermetallic compounds provided in the embodiments of this application; Figure 6 The fourth flowchart of the method for detecting intermetallic compounds provided in the embodiments of this application; Figure 7 The fifth flowchart of the method for detecting intermetallic compounds provided in the embodiments of this application; Figure 8This is the sixth flowchart of a method for detecting intermetallic compounds provided in the embodiments of this application.

[0018] Icons: 100 - Sample to be tested; 110 - Solder ball; 120 - Intermetallic compound. Detailed Implementation

[0019] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. The components of the embodiments of this application described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0020] Therefore, the following detailed description of the embodiments of this application provided in the accompanying drawings is not intended to limit the scope of the claimed application, but merely to illustrate selected embodiments of the application. It should be noted that, unless otherwise specified, the various features in the embodiments of this application can be combined with each other, and the combined embodiments are still within the protection scope of this application.

[0021] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0022] In the description of this application, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the product of this application is in use. They are only for the convenience of describing this application 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 on this application. In addition, the terms "first," "second," and "third," etc., are only used to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0023] In the description of this application, it should also be noted that, unless otherwise expressly specified and limited, the terms "set up," "install," "connect," and "link" 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 application based on the specific circumstances.

[0024] When solder balls are used for soldering, atomic diffusion occurs between the molten solder balls and the copper substrate. Copper atoms diffuse into the solder, while tin atoms migrate back to the surface of the copper substrate, forming an intermetallic compound (IMC) at the interface. The physical properties (such as electrical and thermal conductivity), mechanical properties (such as hardness, elastic modulus, and fracture toughness), and thermal fatigue properties of the IMC directly determine the reliability of the micro-solder joint. Therefore, data analysis of the IMC is necessary to determine the reliability of the micro-solder joint. However, current laboratory analyses of IMC typically involve observing the growth of the IMC in cross-sections using slicing methods, resulting in relatively limited data.

[0025] To solve this technical problem in the prior art, please refer to Figure 1 Embodiment 1 of this application provides a method for detecting intermetallic compounds, comprising: S100: The sample to be tested is heated to allow the intermetallic compound in the sample to grow fully, wherein the sample to be tested is a chip with solder balls.

[0026] Please refer to the reference. Figure 2 The test sample 100 is a chip with solder balls 110. The test sample 100 is first heated to simulate the soldering temperature, thereby allowing the intermetallic compound 120 in the solder balls 110 of the test sample 100 to grow sufficiently, with the growth pattern similar to that of the intermetallic compound 120 during actual soldering. Simulating the soldering temperature to allow the intermetallic compound 120 to grow sufficiently in the initial stage of testing improves the accuracy of the test results and facilitates the observation of the intermetallic compound 120 in subsequent steps.

[0027] It should be noted that in this embodiment, the heating method of the sample 100 to be tested is not limited, as long as the sample 100 to be tested can be heated to the welding temperature to simulate the real welding temperature. The welding temperature is generally 230°~250°.

[0028] S200: The heated sample to be tested is placed in an etching solution for etching until the intermetallic compound is exposed. The temperature of the etching solution is 50°~80°.

[0029] After the intermetallic compound 120 has grown sufficiently, the solder ball 110 needs to be etched with an etchant to expose the intermetallic compound 120 for observation. The etchant can be a mixture used in the prior art for etching the solder ball 110, but the temperature of the etchant must be between 50°C and 80°C.

[0030] It should be noted that the temperature of the corrosive solution can be 50° or 80°, and the ranges specified later also include the endpoint values.

[0031] If the temperature of the etchant is below 50°C, the corrosion rate is slow; if the temperature is above 80°C, although the corrosion rate is fast, it can easily damage the intermetallic compound 120. Therefore, the temperature of the etchant is set between 50°C and 80°C. This ensures a fast corrosion rate, fully exposing the intermetallic compound 120, without damaging it, thus guaranteeing the accuracy of subsequent test data.

[0032] During the corrosion process, the presence of bumps or exposed crystals on the surface of the tin ball 110 can be used to determine whether the intermetallic compound 120 is exposed. Alternatively, based on experience, the corrosion time can be appropriately extended to ensure that the intermetallic compound 120 is exposed.

[0033] Optionally, when the heated sample 100 is placed in the etching solution for etching, the solder balls 110 of the sample 100 should face upwards to prevent damage to the exposed intermetallic compound 120.

[0034] S300: A planar view of the growth of intermetallic compounds is obtained using a scanning electron microscope.

[0035] After the intermetallic compound 120 is exposed, the sample 100 to be tested is observed under a scanning electron microscope to obtain a growth planar image of the intermetallic compound 120. Compared with the existing technology of slicing the solder ball 110 to observe the growth of the intermetallic compound 120 at the cross-section, the growth planar image of the intermetallic compound 120 obtained by the detection method provided in this application embodiment can more comprehensively record the growth data of the intermetallic compound 120.

[0036] In summary, the intermetallic compound detection method provided in this application first heats the sample 100 to simulate the actual soldering temperature of the solder ball 110, allowing the intermetallic compound 120 to grow sufficiently, with the growth pattern closely resembling that of the intermetallic compound 120 during actual soldering. Then, a etching solution at 50°C to 80°C is used to rapidly etch the solder ball 110, fully exposing the intermetallic compound 120 without damaging it. Finally, a scanning electron microscope is used to observe the growth of the intermetallic compound 120, obtaining a growth planar image of the intermetallic compound 120. This growth planar image provides a more comprehensive record of the intermetallic compound 120's growth data. Therefore, compared to existing technologies, the above-described intermetallic compound detection method can more comprehensively, accurately, and rapidly obtain information on the growth of the intermetallic compound 120.

[0037] Alternatively, please refer to Figure 3The sample to be tested is heated to allow the intermetallic compound in the sample to grow sufficiently. The sample to be tested is a chip with solder balls. S110: The sample to be tested is placed in a heating furnace for baking so that the intermetallic compound in the sample can grow fully. The sample to be tested is a chip with solder balls, and the temperature of the heating furnace is 50°~80°.

[0038] Please refer to the reference. Figure 2 In this embodiment, a heating furnace is used to heat the sample 100 to allow the intermetallic compound 120 in the sample 100 to grow sufficiently. The temperature of the heating furnace is set between 50°C and 80°C. The sample 100 is placed in the heating furnace for baking, which raises the temperature of the sample 100 to the welding temperature. After the sample 100 is heated to the welding temperature, it is baked for a period of time to allow the intermetallic compound 120 to grow sufficiently. The temperature of the heating furnace can be precisely controlled, and it can rapidly heat up the sample 100 to be tested. Using the heating furnace to heat the sample 100 to be tested can more accurately simulate the welding temperature, which is efficient and does not damage the intermetallic compound 120.

[0039] Optionally, the heated sample is immersed in an etching solution for etching until the intermetallic compounds are exposed, wherein the temperature of the etching solution is 50°C to 80°C. S210: The heated sample to be tested is placed in the etching solution for etching, and the sample is taken out at preset time intervals to observe the exposure of the intermetallic compound on the tin ball until the intermetallic compound is exposed. The temperature of the etching solution is 50°~80°, and the preset time is gradually shortened.

[0040] In this embodiment, during the etching process of the solder ball 110, the sample 100 to be tested needs to be removed multiple times to observe the exposure of the intermetallic compound 120 on the solder ball 110, and the decision to continue etching is made based on the exposure. Specifically, the decision to continue etching can be made by observing whether bumps or crystals are exposed on the surface of the solder ball 110. If no bumps or crystals are exposed, the sample 100 to be tested needs to be placed back into the etching solution for etching; if bumps or crystals are exposed, etching is stopped. Of course, the volume and / or number of exposed bumps or crystals can also be limited based on experience. If the volume and / or number of exposed bumps or crystals does not exceed the limit, the sample 100 to be tested needs to be placed back into the etching solution for etching; if the volume and / or number of exposed bumps or crystals exceeds the limit, etching is stopped. Please refer to the reference. Figure 4 , Figure 4 This is an observation image of the sample 100 under an optical microscope. The intermetallic compound 120 can be observed using an optical microscope. The corroded sample 100 is placed under the optical microscope to observe the exposure of the intermetallic compound 120.

[0041] As the corrosion progresses, the time interval between observations gradually shortens. By taking out the sample 100 for observation at regular intervals during the corrosion process, the exposure of the intermetallic compound 120 can be monitored in a timely manner, avoiding situations where the intermetallic compound 120 is not sufficiently exposed or the corrosion time is too long.

[0042] Optionally, the corrosive solution is hydrochloric acid with a concentration of 25% to 30%.

[0043] Using hydrochloric acid with a concentration of 25% to 30% as the etching solution can quickly etch the tin ball 110, exposing the intermetallic compound 120 without damaging it. Further enhancing the etching efficiency and effect by heating the solution to maintain the hydrochloric acid temperature between 50°C and 80°C.

[0044] Alternatively, the corrosion solution can be heated by a water bath during the corrosion process.

[0045] Specifically, a first container contains an etching solution, and a second container contains hot water. The first container is placed inside the second container, and the hot water in the second container heats the etching solution in the first container. Once the etching solution reaches the required temperature, the sample 100 to be tested is placed in the first container, and the solder balls 110 of the sample 100 are etched by the etching solution through immersion. During this process, the hot water in the second container continuously heats the etching solution in the first container, stabilizing it at the required temperature.

[0046] Heating the corrosive solution using a water bath and maintaining its temperature throughout the corrosion process can make the temperature of the corrosive solution more uniform, thereby improving corrosion efficiency and effectiveness.

[0047] Preferably, the etching solution is 30% hydrochloric acid. The etching solution is heated in 50°C hot water. After the temperature reaches 50°C as measured by a thermometer, the sample to be tested 100 is placed in the etching solution for heating and etching.

[0048] The same sample 100 was placed in different solvents and tested under different conditions. The test results are shown in the table below:

[0049] As shown in the table above, when the hydrochloric acid concentration is 30% and the temperature is 50°C, the corrosion effect is rapid and has almost no impact on the IMC. Increasing the hydrochloric acid concentration to 35% at a constant temperature has a minor impact on the IMC. However, when the hydrochloric acid concentration is 30% and the temperature is 100°C, although the corrosion effect is rapid, it has a significant impact on the IMC. Therefore, the concentration and temperature range of the etching solution provided in this application embodiment can obtain more comprehensive and accurate growth data for the IMC.

[0050] Embodiment 2 of this application provides another method for detecting intermetallic compounds. This embodiment includes the same steps as Embodiment 1, and this part will not be repeated here. The difference between Embodiment 2 and Embodiment 1 is as follows, please refer to... Figure 5 Before obtaining the growth planar image of the intermetallic compound using scanning electron microscopy, the detection method also includes: S400: Removes complexes formed on solder balls after etching.

[0051] Please refer to the reference. Figure 2 During the etching process of the solder ball 110, a complex is formed on the surface of the solder ball 110. The presence of the complex may affect the subsequent observation of the intermetallic compound 120 by scanning electron microscopy, thus leading to inaccurate growth data of the intermetallic compound 120. Therefore, after etching the solder ball 110 with the etchant and before obtaining the growth planar image of the intermetallic compound 120 using scanning electron microscopy, a step of removing the complex formed on the solder ball 110 is added to further improve the accuracy of the detection results.

[0052] It should be noted that in this embodiment, the method of removing the complex is not limited, as long as the complex can be removed without damaging the intermetallic compound 120.

[0053] Alternatively, please refer to Figure 6 The complexes formed on the solder balls after etching include: S410: Immerse the sample to be tested in a mixture of ammonia and hydrogen peroxide to remove the complex formed on the tin balls after etching.

[0054] The complex is soaked in a mixture of ammonia and hydrogen peroxide for 25-30 seconds. This mixture removes the complex through oxidation and corrosion, offering high efficiency and low cost. Alternatively, please refer to the relevant reference. Figure 2 During immersion, the solder balls 110 of the sample 100 should face downwards to facilitate the removal of the complex. Alternatively, tweezers can be used to hold the sample 100 and immerse only the area near the solder balls 110 in the ammonia and hydrogen peroxide mixture to prevent corrosion of other areas of the sample 100 by the ammonia and hydrogen peroxide mixture.

[0055] Optionally, the ratio of ammonia to hydrogen peroxide is 1:1. In this case, the complex detaches faster and the corrosion effect is better.

[0056] Alternatively, please refer to Figure 7 After removing the complexes formed on the tin balls after etching, the detection method also includes: S500: Immerse the sample in deionized water and then rinse with acetone.

[0057] After removing the complex using a mixture of ammonia and hydrogen peroxide, please refer to the following: Figure 2 The sample 100 to be tested is immersed in deionized water for 25 to 40 seconds. Deionized water contains very few impurities, which can avoid secondary corrosion or contamination of the sample 100, ensuring the cleaning effect and the accuracy of subsequent testing.

[0058] The surface of the sample 100 after being soaked in deionized water may still have trace amounts of organic matter remaining. Acetone, as an organic solvent, can dissolve organic matter. Therefore, soaking the sample 100 in deionized water and then cleaning it with acetone can further remove impurities from the surface of the sample 100, ensuring a cleaning effect and preventing these impurities from affecting the detection of the scanning electron microscope.

[0059] When the sample 100 to be tested is immersed in deionized water, optionally, the solder balls 110 of the sample 100 to be tested face upwards to prevent damage to the intermetallic compound 120 during the immersion process.

[0060] S600: Dry the rinsed sample.

[0061] After cleaning the sample 100, it is necessary to dry the sample 100 to avoid residual moisture on the surface of the sample 100, which may affect the test results.

[0062] Optionally, the rinsed sample 100 can be dried using a heating stage.

[0063] During drying, place the sample 100 to be tested on the heating stage, and remove the sample 100 after a period of time.

[0064] Furthermore, the temperature of the heating stage is 40°~55°, preferably 50°. At this temperature, the drying efficiency is high and no damage is caused to the intermetallic compound 120.

[0065] When drying the sample 100 to be tested, optionally, the solder balls 110 of the sample 100 to be tested face upwards to avoid damage to the intermetallic compound 120.

[0066] Alternatively, please refer to Figure 8Before obtaining the growth planar image of the intermetallic compound using scanning electron microscopy, the detection method also includes: S700: A conductive layer is electroplated on the surface of the exposed intermetallic compound.

[0067] Please refer to the reference. Figure 4 Before photographing the intermetallic compound 120 using a scanning electron microscope, a conductive layer is electroplated on the surface of the intermetallic compound 120. This ensures good conductivity of the intermetallic compound 120 during imaging, resulting in a clearer image of the intermetallic compound 120 in the growth planar image. Step S700 is preferably performed after step S600 to further improve the clarity of the intermetallic compound 120 in the growth planar image.

[0068] Optionally, the conductive layer is a platinum layer.

[0069] Platinum has excellent electrical conductivity and high stability. Plating platinum on the surface of intermetallic compound 120 can make intermetallic compound 120 clearly visible in the growth planar diagram. Figure 2 A planar view of the growth of intermetallic compound 120 obtained by scanning electron microscopy when a platinum layer is electroplated onto the surface of the compound as a conductive layer. Figure 2 As can be seen, after platinum is electroplated on the surface of intermetallic compound 120, the conductivity of intermetallic compound 120 becomes excellent, and the growth planar image of intermetallic compound 120 obtained by scanning electron microscope clearly shows intermetallic compound 120.

[0070] Optionally, the detection parameters can be adjusted, and the intermetallic compound 120 can be detected multiple times to optimize the detection method for the intermetallic compound.

[0071] The detection parameters include, but are not limited to: the heating temperature of the sample 100 to be tested, the concentration and temperature of the etching solution, the etching time, the soaking time for removing complexes, the soaking time in deionized water, and the rinsing time with acetone.

[0072] By repeatedly adjusting the detection parameters and repeating the above detection steps (S100~S700, etc.), multiple growth planar images of intermetallic compound 120 are obtained. Then, based on the condition of intermetallic compound 120 shown in the growth planar images, the detection parameters are adjusted in reverse to optimize the above detection method of intermetallic compound, so as to further improve the accuracy and comprehensiveness of the growth data of intermetallic compound 120.

[0073] It should be understood that although the steps in the flowchart are shown sequentially as indicated by the arrows, these steps are not necessarily executed in the order indicated by the arrows. Unless explicitly stated herein, there is no strict order constraint on the execution of these steps, and they can be executed in other orders. Moreover, at least some steps in the flowchart may include multiple steps or stages, which are not necessarily completed at the same time, but can be executed at different times. The execution order of these steps or stages is not necessarily sequential, but can be performed alternately or in turn with other steps or at least some of the steps or stages in other steps.

[0074] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A method for detecting intermetallic compounds, characterized in that, include: The sample to be tested is heated to allow the intermetallic compound in the sample to grow sufficiently, wherein the sample to be tested is a chip with solder balls; The heated sample to be tested is placed in an etching solution for etching until the intermetallic compound is exposed, wherein the temperature of the etching solution is 50°~80°. A growth plan view of the intermetallic compound was obtained using a scanning electron microscope.

2. The method for detecting intermetallic compounds as described in claim 1, characterized in that, Before obtaining the growth planar image of the intermetallic compound using a scanning electron microscope, the detection method further includes: Remove the complex formed on the tin ball after etching.

3. The method for detecting intermetallic compounds as described in claim 2, characterized in that, The complex formed on the solder ball after corrosion removal includes: The sample to be tested is immersed in a mixture of ammonia and hydrogen peroxide to remove the complex formed on the tin ball after etching.

4. The method for detecting intermetallic compounds as described in claim 1, characterized in that, The corrosive solution is hydrochloric acid with a concentration of 25% to 30%.

5. The method for detecting intermetallic compounds as described in claim 1, characterized in that, The step of immersing the heated sample in the etching solution for etching includes: The heated sample is placed in an etching solution for etching, and the sample is taken out at preset time intervals to observe the exposure of intermetallic compounds on the tin ball. The preset time intervals are gradually shortened.

6. The method for detecting intermetallic compounds as described in claim 1, characterized in that, The heating of the sample to be tested includes: The sample to be tested is placed in a heating furnace for baking, wherein the temperature of the heating furnace is 50°~80°.

7. The method for detecting intermetallic compounds as described in claim 3, characterized in that, After removing the complexes formed on the tin balls after etching, the detection method further includes: The sample to be tested was immersed in deionized water and then rinsed with acetone. The rinsed sample is then dried.

8. The method for detecting intermetallic compounds as described in claim 1, characterized in that, Before obtaining the growth planar image of the intermetallic compound using a scanning electron microscope, the detection method further includes: A conductive layer is electroplated onto the exposed surface of the intermetallic compound.

9. The method for detecting intermetallic compounds as described in claim 1, characterized in that, The corrosion solution is heated by a water bath during the corrosion process.

10. The method for detecting intermetallic compounds as described in claim 7, characterized in that, The step of immersing the heated sample in the etching solution for etching includes: The heated sample is placed in the etching solution with the solder balls facing upwards for etching. The step of immersing the sample to be tested in a mixture of ammonia and hydrogen peroxide includes: The sample to be tested is immersed in a mixture of ammonia and hydrogen peroxide with the solder balls facing down. The step of immersing the sample to be tested in deionized water and then rinsing it with acetone includes: Immerse the sample in deionized water with the solder balls facing upwards, then rinse with acetone. The step of drying the rinsed sample to be tested includes: Dry the rinsed sample with the solder balls facing upwards.

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