Method and system for testing electromigration reliability of high-temperature electronic packaging interconnection structure

Abstract

The invention discloses a method and a system for testing the electromigration reliability of a high-temperature electronic packaging interconnection structure, and relates to the technical field of electromigration reliability detection. The method comprises the following specific steps: detecting electromagnetic frequency information of ripple waves and eddy currents at two ends of an interconnection line through a detection device; fusing the electromagnetic frequency information to form a multivariate fusion pedigree; and amplifying the multivariate fusion pedigree by using an amplifier, analyzing the characteristics of the multivariate fusion pedigree, and obtaining electromigration reliability evolution and accumulated damage information. On the basis of eliminating electromagnetic frequency interference and carrying out structure optimization on the device, a high-temperature electronic packaging interconnection structure electromigration reliability evolution test is carried out based on a ripple current-eddy current multi-element fusion electromagnetic spectrum system, and the test is more accurate and sensitive.

Description

Technical Field

[0001] The present invention relates to the technical field of electromigration reliability detection, and in particular to a method and system for testing the electromigration reliability of a high-temperature electronic packaging interconnection structure. Background Art

[0002] With the development of high-density and miniaturized packaging technology, especially 3D packaging technology, the electromigration reliability of high-temperature integrated packaging multi-layer interconnection structures faces severe challenges and has become a key factor restricting the improvement of my country's high-temperature and high-density circuits, especially the technical level and competitiveness of integrated circuits. Electromigration, as a particularly important reliability problem in interconnects, can induce disconnection or short circuits in interconnects, which is manifested as the accumulation of voids or hillocks in metal wires, causing interruptions or errors in signal transmission, and causing the life of interconnects to decrease or fail. Therefore, the detection of electromigration reliability damage process of high-temperature electronic packaging interconnection structures is an important guarantee for the safe and stable operation of integrated circuits. The direct contact detection method is simple and easy, but it requires complex preparation of high-temperature electronic packaging interconnection structures, and it is difficult to truly reflect the microscopic electromigration cumulative damage under the actual working state of the interconnection structure; the impedance detection method has a clear principle and can effectively reflect the occurrence of disconnection, short circuit or accumulation of voids and hillocks, but it is not sensitive to the potential damage evolution and early damage process changes of electromigration of interconnection structures. Therefore, it is necessary to explore a more accurate and sensitive test method for the microscopic evolution of electromigration reliability of high-temperature electronic packaging interconnection structures that truly reflects the electromigration failure mechanism. Summary of the invention

[0003] The object of the present invention is to provide a method and system for testing the electromigration reliability of a high-temperature electronic packaging interconnection structure, so as to solve the problems raised in the background technology.

[0004] To achieve the above object, the present invention provides the following solution: a method for testing the electromigration reliability of a high-temperature electronic packaging interconnect structure, the specific steps of which include the following:

[0005] Detecting electromagnetic frequency information of ripples and eddy currents at both ends of the interconnection line by a detection device;

[0006] fusing the electromagnetic frequency information to form a multi-dimensional fusion spectrum;

[0007] The multi-element fusion spectrum is amplified by an amplifier, and the frequency change of the multi-element fusion spectrum is analyzed to obtain the electromigration reliability evolution and cumulative damage information.

[0008] Preferably, the amplifier is a dual-link symmetrical amplifier.

[0009] Preferably, the detection device includes an aluminum shielded cylindrical test body, a temperature sensor, and a heater; wherein the aluminum shielded cylindrical test body has a double-handled pipe-shaped gap, the first handle hole is connected to the pipe bowl gap, the temperature sensor is placed in the first handle hole and close to the package interconnect line to be tested, a hollow copper tube is inserted into the second handle hole, and the power cord connecting the heater and the temperature sensor is passed through the hollow copper tube to pass out of the test chamber.

[0010] Preferably, the hollow copper tube is fixed to the bottom of the aluminum cylindrical plate and the outer aluminum box.

[0011] Preferably, the method further comprises displaying the multi-fusion lineage.

[0012] Preferably, the specific steps of fusing the electromagnetic frequency information are:

[0013] Assume that the main frequency of the electromagnetic frequency of the ripple and eddy current at both ends of the interconnection line at time t is: F t1 and F t2 ;

[0014] The spectrum of multivariate fusion is:

[0015] Where E is the main frequency fusion value of the ripple and eddy current electromagnetic frequency at both ends of the interconnection line, W ti is the weight of the main frequency fusion of ripple and eddy current electromagnetic frequency at time t.

[0016] On the other hand, a high-temperature electronic packaging interconnect structure electromigration reliability test system is provided, comprising a detection module, a fusion module, and an amplification analysis module; wherein:

[0017] The detection module is used to detect electromagnetic frequency information of ripples and eddy currents at both ends of the interconnection line through a detection device;

[0018] The fusion module is used to fuse the electromagnetic frequency information to form a multi-dimensional fusion spectrum;

[0019] The amplification and analysis module is used to amplify the multivariate fusion spectrum using an amplifier, analyze the characteristics of the multivariate fusion spectrum, and obtain electromigration reliability evolution and cumulative damage information.

[0020] According to the specific embodiments provided by the present invention, the present invention discloses the following technical effects: on the basis of eliminating electromagnetic frequency interference and optimizing the structure of the device, the electromigration reliability evolution test of the high-temperature electronic packaging interconnection structure is carried out based on the electromagnetic spectrum of ripple-eddy current multi-fusion. The present invention detects the electromagnetic frequency spectrum of ripple and eddy current and fuses them to form a multi-fusion spectrum, and amplifies and analyzes the characteristics of the multi-fusion spectrum to obtain information on the evolution of electromigration reliability and cumulative damage, which is more accurate and sensitive. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0022] Figure 1 is a flow chart of the method of the present invention;

[0023] Figure 2 It is the principle structure diagram of the amplifier of the present invention;

[0024] Figure 3 It is a structural diagram of the detection device of the present invention;

[0025] Figure 4 This is a graph showing the change of the electromagnetic spectrum power spectrum of the multivariate fusion of sample 1 of the present invention over time;

[0026] Figure 5 This is a graph showing the change in the electromagnetic spectrum power spectrum of the multivariate fusion of sample 2 of the present invention over time. DETAILED DESCRIPTION

[0027] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0028] The purpose of the present invention is to provide a method for testing the electromigration reliability of a high temperature electronic packaging interconnection structure. Figure 1 As shown, the specific steps include the following:

[0029] S1, detecting electromagnetic frequency information of ripples and eddy currents at both ends of the interconnection line by a detection device;

[0030] S2, integrating electromagnetic frequency information to form a multi-dimensional fusion spectrum;

[0031] S3. Use an amplifier to amplify the multi-fusion spectrum, analyze the frequency changes of the multi-fusion spectrum, and obtain the electromigration reliability evolution and cumulative damage information.

[0032] Furthermore, each circuit module of the detection device will generate electromagnetic signals. These electromagnetic information may mask the electromagnetic signals generated by the voltage ripple and eddy current caused by the electromigration of the package interconnect structure, reducing the sensitivity of the test. Therefore, it is necessary to first extract and amplify the voltage fluctuations and eddy currents caused by electromigration, filter out the electromagnetic frequency information generated by the voltage ripple and eddy current caused by electromigration and amplify them, and overcome the interference signals of the system background. Based on comprehensive performance considerations, the present invention designs a dual-linkage symmetrical amplifier, which not only greatly improves the low-frequency suppression ratio, but also performs a redundant design, such as Figure 2 shown.

[0033] Furthermore, the detection device includes an aluminum shielded cylindrical test body, a temperature sensor, and a heater; the electromagnetic signals generated by the voltage ripple and eddy current caused by the electromigration of the package interconnect structure are very sensitive to the electromagnetic interference (EMI) of the environment, especially the heater and the temperature sensor equipment. Even high-frequency interference, which can be coupled with the measurement chain and corrected by the nonlinearity in the circuit, can also cause a significant increase in the interference signal, which may completely mask the frequency information caused by the electromigration to be detected. Therefore, it is necessary to ensure the effective shielding of electromagnetic interference. The present invention designs an aluminum shielded cylinder with a double-pipe-handled pipe-shaped gap in the middle to shield and optimize electromagnetic interference.

[0034] like Figure 3 As shown, the small hole (3 mm in diameter) on the handle of the upper part of the aluminum shielded cylinder is connected to the gap in the middle of the pipe bowl, where the PT100 temperature sensor is placed and close to the package interconnection line to be tested. The gap space in the pipe bowl allows the high-temperature electric heater to maintain good heat transfer with the upper part. A hollow copper tube is inserted into the small hole on the side handle of the lower part of the aluminum shielded cylinder. The copper tube allows the power line connecting the thermostatic heater and the temperature sensor to pass out of the test chamber. The copper tube is tightly fixed to the bottom of the aluminum cylinder plate and the external aluminum box.

[0035] This structural design allows the cables supplying the heater power supply and the cables connected to the temperature sensor to not pass through the shielding surface. Through simulation experiments, this structural design greatly reduces the electromagnetic interference of the detection system. Under this structure, an external programmable power supply and computer can be used to realize a fairly flexible digital temperature control system without introducing a significant level of electromagnetic interference, thereby improving the sensitivity of the measurement chain.

[0036] Furthermore, the specific steps for fusing electromagnetic frequency information are as follows:

[0037] Assume that the main frequency of the electromagnetic frequency of the ripple and eddy current at both ends of the interconnection line at time t is: F t1 and F t2 ;

[0038] The spectrum of multivariate fusion is:

[0039] Where E is the main frequency fusion value of the ripple and eddy current electromagnetic frequency at both ends of the interconnection line, W ti is the weight of the main frequency fusion of ripple and eddy current electromagnetic frequency at time t.

[0040] Computers are used to collect, fuse, control, analyze and display the ripple-eddy current multi-electromagnetic frequency spectrum. Dual-channel PCI-4451 dynamic signal acquisition board is connected to the computer to realize automatic data collection, fusion, control and reading of electromagnetic frequency spectrum and display of main spectrum. One of the two input channels of PCI-4451 is connected to the output of dual-linkage symmetrical amplifier for detection. A constant temperature control system is formed through computers, digital-to-analog converters, programmable power supplies and temperature sensors. The constant temperature stability of the digital temperature controller is less than 0.01℃.

[0041] The output signal of the dual-link symmetrical voltage-frequency amplifier collected by PCI-4451 is processed in real time in the computer to estimate and analyze the electromigration reliability evolution of the package interconnect structure, and saved for post-processing and time domain analysis. The temperature value and temperature interval can be set through the calculation system software to meet any constant temperature test and test. After the temperature setting value is started, the actual test begins. The test time depends on the minimum frequency observed until a frequency signal of several hundred MHz is detected.

[0042] The method of the present invention is described below by specific embodiments:

[0043] The electromigration test samples are shown in Table 1, and the acceleration test conditions of the entire electromigration process are shown in Table 2.

[0044] sample Length(μm) Width(μm) Thickness(μm) Resistance(Ω) Copper strip 1 1325 2 0.5 30 Copper Strip 2 1335 1.7 0.4 40

[0045] Table 1

[0046] sample Acceleration temperature (℃) Acceleration current (mA) Test temperature (℃) Test current (mA) Test time interval (h) Copper strip 1 100 17 20 12 3 Copper Strip 2 120 20 20 9 4

[0047] Table 2

[0048] Of the two samples tested, sample 1 and sample 2 failed after 57 hours and 45 hours of accelerated testing, respectively. The entire electromigration process was tested based on the ripple-eddy current multi-electromagnetic frequency spectrum. The test results are as follows: Figure 4 and Figure 5 shown.

[0049] As can be seen from the figure, the electromigration evolution process is divided into three stages: (1) The noise power spectrum of the sample before aging and the initial stage of electromigration. When electromigration does not occur (t = 0h), the amplitude of the interconnected electromigration power spectrum is the smallest, which is mainly manifested by the combined effect of 1 / f electromigration caused by grain boundary scattering and electromigration caused by internal scattering of the grains. With the beginning of aging, the electromigration process is stimulated. In the initial stage of electromigration, vacancies are gradually generated and begin to migrate to the grain boundaries. In this stage, the vacancy concentration increases linearly with time. Electromigration is mainly caused by the scattering of carriers by vacancies. At this time, the spectrum is significantly increased compared with that before aging, and the slope of the spectrum increases at the same time, showing a more obvious 1 / f electromigration characteristic. (2) It is the middle stage of electromigration. At this time, the vacancy concentration has tended to saturation and gathered at the grain boundaries. Compared with the initial stage of electromigration, the spectrum amplitude at this time has not increased significantly. This is because the vacancy concentration no longer increases significantly. The accumulated vacancies accumulate energy under the action of the stress field, and electromigration damage continues to accumulate. (3) Electromigration during the nucleation and growth of voids. At the beginning, the spectrum amplitude increased significantly, which means that the mechanism of electromigration has changed from vacancy scattering to void scattering. Compared with the traditional resistance characterization parameter that assumes that void nucleation occurs when the resistance changes by 20%, the spectrum amplitude is much more sensitive. After the void nucleates, it will grow rapidly and cause the strip to break. After several hours, the power spectrum is distorted.

[0050] On the other hand, a high-temperature electronic packaging interconnect structure electromigration reliability test system is provided, comprising a detection module, a fusion module, and an amplification analysis module; wherein:

[0051] A detection module, used for detecting electromagnetic frequency information of ripples and eddy currents at both ends of the interconnection line through a detection device;

[0052] A fusion module is used to fuse electromagnetic frequency information to form a multi-dimensional fusion spectrum;

[0053] The amplification analysis module is used to amplify the multivariate fusion spectrum using an amplifier, analyze the characteristics of the multivariate fusion spectrum, and obtain the electromigration reliability evolution and cumulative damage information.

[0054] The principles and implementation methods of the present invention are described in this article using specific examples. The description of the above embodiments is only used to help understand the method and core idea of ​​the present invention. At the same time, for those skilled in the art, according to the idea of ​​the present invention, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as limiting the present invention.

Claims

1. A method for testing the electromigration reliability of a high-temperature electronic packaging interconnect structure, characterized in that: The specific steps include the following: Detecting electromagnetic frequency information of ripples and eddy currents at both ends of the interconnection line by a detection device; fusing the electromagnetic frequency information to form a multi-dimensional fusion spectrum; The multivariate fusion spectrum is amplified by an amplifier, and the frequency change of the multivariate fusion spectrum is analyzed to obtain the electromigration reliability evolution and cumulative damage information.

2. A high temperature electronic packaging interconnect structure electromigration reliability testing method according to claim 1, characterized in that: The amplifier is a dual-link symmetrical amplifier.

3. The electromigration reliability testing method for a high temperature electronic packaging interconnect structure according to claim 1, characterized in that: The detection device includes an aluminum shielded cylindrical test body, a temperature sensor, and a heater; wherein the aluminum shielded cylindrical test body has a double-handled pipe-shaped gap, the first handle hole is connected to the pipe bowl gap, the temperature sensor is placed in the first handle hole and close to the package interconnect line to be tested, a hollow copper tube is inserted into the second handle hole, and the power cord connecting the heater and the temperature sensor is passed out of the test chamber through the hollow copper tube.

4. A high temperature electronic packaging interconnect structure electromigration reliability testing method according to claim 3, characterized in that: The hollow copper tube is fixed to the bottom of the aluminum cylinder plate and the outer aluminum box.

5. The electromigration reliability testing method for high temperature electronic packaging interconnection structure according to claim 1, characterized in that: Also included is displaying the multiplex fusion repertoire.

6. The electromigration reliability testing method of a high temperature electronic packaging interconnection structure according to claim 1, characterized in that: The specific steps of fusing the electromagnetic frequency information are as follows: Assume that the main frequency of the electromagnetic frequency of the ripple and eddy current at both ends of the interconnection line at time t is: F t1 and F t2 ; The spectrum of multivariate fusion is: Where E is the main frequency fusion value of the ripple and eddy current electromagnetic frequency at both ends of the interconnection line, W ti is the weight of the main frequency fusion of ripple and eddy current electromagnetic frequency at time t.

7. A high temperature electronic packaging interconnect structure electromigration reliability test system, characterized in that: It includes detection module, fusion module and amplification analysis module; among them, The detection module is used to detect electromagnetic frequency information of ripples and eddy currents at both ends of the interconnection line through a detection device; The fusion module is used to fuse the electromagnetic frequency information to form a multi-dimensional fusion spectrum; The amplification and analysis module is used to amplify the multivariate fusion spectrum using an amplifier, analyze the characteristics of the multivariate fusion spectrum, and obtain electromigration reliability evolution and cumulative damage information.

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