阅读说明：本技术 多层低温共烧陶瓷基板的无损失效检测方法 (Nondestructive failure detection method for multilayer low-temperature co-fired ceramic substrate ) 是由 迟雷 彭浩 高金环 黄杰 陈龙坡 于 2021-06-15 设计创作，主要内容包括：本发明涉及半导体器件失效技术领域,提供了一种多层低温共烧陶瓷基板的无损失效检测方法,包括对待测基板进行第一检测,基于第一检测得到的网络通断情况,确定失效网络号；对失效网络号内的线路进行第二检测,确定待测基板的失效位置；对失效位置进行分析,确定待测基板的失效机理。本发明的多层低温共烧陶瓷基板的无损失效检测方法可通过无损的检测手段,不仅可以定位多层陶瓷基板的失效网络号,而且可以通过进一步检测确定失效的具体部位,并进一步分析判断发生的失效模式,最终确定引发失效或缺陷的失效机理。采用本发明的检测方法可以快速、准确的确定失效位置,且便于进一步确定失效机理。(The invention relates to the technical field of semiconductor device failure, and provides a nondestructive failure detection method of a multilayer low-temperature co-fired ceramic substrate, which comprises the steps of carrying out first detection on a substrate to be detected, and determining a failure network number based on the network on-off condition obtained by the first detection; performing second detection on the line in the failure network number, and determining the failure position of the substrate to be detected; and analyzing the failure position to determine the failure mechanism of the substrate to be tested. The nondestructive failure detection method of the multilayer low-temperature co-fired ceramic substrate can not only locate the failure network number of the multilayer ceramic substrate by a nondestructive detection means, but also determine the specific failure part by further detection, further analyze and judge the failure mode and finally determine the failure mechanism causing failure or defects. The detection method can quickly and accurately determine the failure position and is convenient for further determining the failure mechanism.)

1. A nondestructive failure detection method of a multilayer low-temperature co-fired ceramic substrate is characterized by comprising the following steps:

carrying out first detection on a substrate to be detected, and determining a failure network number based on the network on-off condition obtained by the first detection;

performing second detection on the line in the failure network number, and determining the failure position of the substrate to be detected;

and analyzing the failure position to determine the failure mechanism of the substrate to be tested.

2. The nondestructive failure detection method of the multilayer low-temperature co-fired ceramic substrate of claim 1, wherein the second detection of the line in the failure network number to determine the failure position of the substrate to be detected comprises:

testing a line in a target failure network number by adopting an impedance testing system to obtain a scattering parameter of the target failure network number, wherein the target failure network number is any one of all the failure network numbers;

determining a failure position in the target failure network number according to the scattering parameters of the target failure network number;

wherein the impedance testing system comprises: the device comprises a vector network analyzer, an impedance test circuit and a coaxial connecting wire; the impedance test circuit comprises a probe station and a radio frequency probe;

the vector network analyzer is electrically connected with one end of the probe station through the coaxial connecting line, the substrate to be tested is arranged on the probe station, and the radio frequency probe is used for testing the substrate to be tested.

3. The method for nondestructive failure detection of a multilayer low-temperature co-fired ceramic substrate of claim 2, wherein the determining the failure location within the target failure network number according to the scattering parameters of the target failure network number comprises:

and determining the position corresponding to the peak point of the S11 curve in the scattering parameters of the target failure network number as the failure position in the target failure network number.

4. The nondestructive failure detection method of the multilayer low-temperature co-fired ceramic substrate according to claim 1 or 2, wherein the performing a first test on the substrate to be tested and determining the failure network number based on the network on-off condition of the substrate to be tested comprises:

testing the circuits in all network numbers in the substrate to be tested by using a flying probe test on-off instrument to obtain test data corresponding to all the network numbers;

and determining the failure network number according to a preset relation between a preset value and the test data.

5. The nondestructive failure detection method of the multilayer low-temperature co-fired ceramic substrate of claim 4, wherein the step of testing the lines in all network numbers in the substrate to be tested by using a flying probe test on-off instrument to obtain test data corresponding to all the network numbers comprises:

respectively carrying out open circuit/conduction test and short circuit/insulation test on the lines in all the network numbers to obtain a first resistance value and a second resistance value corresponding to the target network number; the target network number is any one of all the network numbers;

the determining the failure network number according to the preset value and the preset relation of the test data comprises:

and determining the number of the failure network according to the preset open circuit valve resistance value and the first resistance value, and the preset insulation valve resistance value and the second resistance value.

6. The nondestructive failure detection method of the multilayer low-temperature co-fired ceramic substrate of claim 3, wherein after performing the second detection on the line in the failure network number and determining the failure position of the substrate to be detected, the method further comprises:

converting the scattering parameters from a frequency domain to a time domain to obtain the impedance of all positions in the failure network number;

and determining a failure mode according to the impedance corresponding to the peak point.

7. The nondestructive failure detection method of the multilayer low-temperature co-fired ceramic substrate of claim 1, wherein the analyzing the failure location to determine the failure mechanism of the substrate to be tested comprises:

and adopting X-rays to inspect the failure position, and determining the failure mechanism of the substrate to be detected according to the inspection result.

8. The nondestructive failure detection method of the multilayer low-temperature co-fired ceramic substrate of claim 1, wherein the analyzing the failure location to determine the failure mechanism of the substrate to be tested comprises:

and inspecting the failure position by adopting an acoustic scanning microscope, and determining the failure mechanism of the substrate to be detected according to the scanning image.

9. The nondestructive failure detection method of the multilayer low-temperature co-fired ceramic substrate of claim 1, wherein the analyzing the failure location to determine the failure mechanism of the substrate to be tested comprises:

and inspecting the inside of the failure position by adopting a magnetic microscopic defect positioning technology, and determining the failure mechanism of the substrate to be detected according to an inspection result.

10. The nondestructive failure detection method of the multilayer low-temperature co-fired ceramic substrate of claim 1, wherein the analyzing the failure location to determine the failure mechanism of the substrate to be tested comprises:

and inspecting the inside of the failure position by adopting a synchronous thermal emission analysis technology, and determining the failure mechanism of the substrate to be detected according to an inspection result.

Technical Field

The invention relates to the technical field of low-temperature co-fired ceramic failure positioning, in particular to a nondestructive failure detection method of a multilayer low-temperature co-fired ceramic substrate.

Background

Low Temperature Co-fired Ceramic (LTCC) is the most ideal substrate material for developing and producing high-density T/R components of phased array radars such as airborne, shipborne and spaceborne, and is one of key technologies for realizing miniaturization, light weight, high reliability and Low cost of the components. The multilayer LTCC substrate can integrate a passive element resistor, an inductor and a capacitor, and can integrate a mixed signal design of a microwave transmission line, a logic control line and a power line in the same multilayer LTCC three-dimensional microwave transmission structure, so that the size and the weight of a T/R assembly are reduced to the maximum extent.

Because the multilayer LTCC substrate has excellent performance, the T/R assembly manufactured by adopting the multilayer LTCC substrate technology has more quality problems such as substrate cracking, internal defects, poor electrode reliability and the like in the using process. In the inspection process, the obvious failure phenomenon of some products occurs before the products are used, while most products do not show obvious performance deterioration before the products are used, but are influenced by the stresses such as fatigue, mechanical stress, temperature stress, over-current stress and the like in the long-term use process, and the T/R assembly is inevitably subjected to the failure phenomena such as open circuit, short circuit or electrical parameter drift. If the above-described T/R module with quality problems is used, there is a serious reliability risk.

However, the current method for nondestructive failure detection of the multilayer LTCC substrate can only determine the failure network number, but cannot locate the exact failure position without damage.

Disclosure of Invention

In view of this, the embodiment of the invention provides a nondestructive failure detection method for a multilayer low-temperature co-fired ceramic substrate, so as to solve the problem that the failure position cannot be located nondestructively in the prior art.

The embodiment of the invention provides a nondestructive failure detection method of a multilayer low-temperature co-fired ceramic substrate, which comprises the following steps:

carrying out first detection on a substrate to be detected, and determining a failure network number based on the network on-off condition obtained by the first detection;

performing second detection on the line in the failure network number, and determining the failure position of the substrate to be detected;

and analyzing the failure position to determine the failure mechanism of the substrate to be tested.

In a possible implementation manner, the performing a second detection on the line in the failure network number to determine the failure position of the substrate to be tested includes:

testing a line in a target failure network number by adopting an impedance testing system to obtain a scattering parameter of the target failure network number, wherein the target failure network number is any one of all the failure network numbers;

determining a failure position in the target failure network number according to the scattering parameters of the target failure network number;

wherein the impedance testing system comprises: the device comprises a vector network analyzer, an impedance test circuit and a coaxial connecting wire; the impedance test circuit comprises a probe station and a radio frequency probe;

the vector network analyzer is electrically connected with one end of the probe station through the coaxial connecting line, the substrate to be tested is arranged on the probe station, and the radio frequency probe is used for testing the substrate to be tested.

In some embodiments, the determining the failure location within the target failed network number according to the scattering parameters of the target failed network number includes:

and determining the position corresponding to the peak point of the S11 curve in the scattering parameters of the target failure network number as the failure position in the target failure network number.

In a possible implementation manner, the performing a first test on the substrate to be tested, and determining a failure network number based on a network on-off condition of the substrate to be tested includes:

testing the circuits in all network numbers in the substrate to be tested by using a flying probe test on-off instrument to obtain test data corresponding to all the network numbers;

and determining the failure network number according to a preset relation between a preset value and the test data.

In some embodiments, the testing the lines in all network numbers in the substrate to be tested by using the flying probe test on-off instrument to obtain test data corresponding to all network numbers includes:

respectively carrying out open circuit/conduction test and short circuit/insulation test on the lines in all the network numbers to obtain a first resistance value and a second resistance value corresponding to the target network number; the target network number is any one of the network numbers;

the determining the failure network number according to the preset value and the preset relation of the test data comprises:

and determining the number of the failure network according to the preset open circuit valve resistance value and the first resistance value, and the preset insulation valve resistance value and the second resistance value.

In a possible implementation manner, after performing the second detection on the line in the failure network number and determining the failure position of the substrate to be tested, the method further includes:

converting the scattering parameters from a frequency domain to a time domain to obtain the impedance of all positions in the failure network number;

and determining a failure mode according to the impedance corresponding to the peak point.

In a possible implementation manner, the analyzing the failure location to determine the failure mechanism of the substrate to be tested includes:

and adopting X-rays to inspect the failure position, and determining the failure mechanism of the substrate to be detected according to the inspection result.

In a possible implementation manner, the analyzing the failure location to determine the failure mechanism of the substrate to be tested includes:

and inspecting the failure position by adopting an acoustic scanning microscope, and determining the failure mechanism of the substrate to be detected according to the scanning image.

In a possible implementation manner, the analyzing the failure location to determine the failure mechanism of the substrate to be tested includes:

and inspecting the inside of the failure position by adopting a magnetic microscopic defect positioning technology, and determining the failure mechanism of the substrate to be detected according to an inspection result.

In a possible implementation manner, the analyzing the failure location to determine the failure mechanism of the substrate to be tested includes:

and inspecting the inside of the failure position by adopting a synchronous thermal emission analysis technology, and determining the failure mechanism of the substrate to be detected according to an inspection result.

The embodiment of the invention provides a nondestructive failure detection method of a multilayer low-temperature co-fired ceramic substrate, which comprises the steps of firstly carrying out first detection on the substrate, and determining a failure network number according to the network on-off condition obtained by the first detection; secondly, performing second detection on the line in the failure network number to determine a failure position; and finally, analyzing the failure position to determine the failure mechanism. Therefore, the nondestructive failure positioning can be realized through a simple and quick method, and the failure mechanism can be determined after the defect positioning.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings needed to be used in the embodiments or the prior art descriptions will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings based on these drawings without inventive exercise.

FIG. 1 is a flowchart of a nondestructive failure detection method for a multi-layer low-temperature co-fired ceramic substrate according to an embodiment of the present invention;

FIG. 2 is a schematic diagram of a testing process of a flying probe testing on-off device provided by an embodiment of the invention;

fig. 3 is a schematic diagram of an impedance testing system according to an embodiment of the present invention.

Detailed Description

In the following description, for purposes of explanation and not limitation, specific details are set forth, such as particular system structures, techniques, etc. in order to provide a thorough understanding of the embodiments of the invention. It will be apparent, however, to one skilled in the art that the present invention may be practiced in other embodiments that depart from these specific details. In other instances, detailed descriptions of well-known systems, devices, circuits, and methods are omitted so as not to obscure the description of the present invention with unnecessary detail.

In order to explain the technical means of the present invention, the following description will be given by way of specific examples.

The multilayer LTCC substrate is a folded structure form of a planar circuit, input and output ends between layers of the substrate are connected with each other in a vertical direction through metalized through holes and conducting wires so as to form an electric network, and all the electric networks on the substrate have unique network numbers.

In the process of manufacturing the multilayer LTCC substrate, vertical interconnection is usually realized by lamination, which is an important way for realizing conversion from two dimensions to three dimensions and is also a key technology of multilayer interconnection. The current common practice is to do this by mechanical cooperation between the locating holes on the green porcelain and the corresponding locating pins on the device. Although the alignment method is simple, the alignment error is large, and the vertical interconnection is easy to fail. The defects or failures of the ceramic substrates have a great relationship with the production process, for example, when the pressure is not proper or uniform during lamination, the temperature is not proper, the sintering conditions are not tightly controlled, so that the substrates of each layer cannot be organically combined together, and delamination can be generated after a temperature cycle test. The ceramic body substrate blistering is related to the too fast low-temperature section temperature rise during sintering, the low-temperature section temperature rise should be relatively slow to remove the organic adhesive in the ceramic material, if the temperature rise is too fast, the adhesive cannot be completely discharged, the ceramic body compactness is poor during sintering, and bubbles are generated; the cracks of the substrate porcelain body are related to the granularity and the uniformity of the porcelain body powder, and the uniformity of the pressure and the sintering condition related to the gold-conductive cracks and insufficient bonding are mainly related to the viscosity and the granularity of the additive materials such as the bonding agent in the gold-conductive slurry and the physical characteristics of other materials; and secondly, the thermal expansion coefficient mismatch of the gold conductor and the porcelain body has a certain relation. The adhesion of gold conductive material to the dielectric is also one of the factors responsible for substrate delamination.

The existing nondestructive failure positioning method of the multilayer LTCC substrate mainly comprises an appearance inspection method, a comparison test method between test points by other applicable instruments such as a graphic instrument and the like, a function test method and a flying probe test method by using the same or similar circuit with a failed component. These methods have many disadvantages, such as usually only being able to determine the failing network number, and not being able to locate a specific failing location. The method can only detect obvious failures such as open circuit, short circuit and the like, and can not effectively detect slight defects of cracks, ceramic delamination and ceramic substrate blistering of the substrate ceramic body. For more complex multi-layer LTCC substrates, X-ray and sonography testing methods, while relatively complete images can be obtained, failure sites of multi-layer LTCC substrates are difficult to locate directly due to image quality limitations and imperfect three-dimensional imaging techniques.

In order to solve the problems in the prior art, the embodiment of the invention provides a nondestructive failure detection method for a multilayer low-temperature co-fired ceramic substrate.

As shown in fig. 1, the nondestructive failure detection method for a multilayer low-temperature co-fired ceramic substrate according to an embodiment of the present invention may include the following steps:

step S110, carrying out first detection on the substrate to be detected, and determining a failure network number based on the network on-off condition obtained by the first detection.

After receiving the failure substrate to be tested, before performing the first test, the failure background adjustment, the preliminary confirmation of the failure of the substrate to be tested, and the design of the failure positioning scheme of the substrate to be tested are required to be performed on the substrate to be tested.

Firstly, a failure background investigation is carried out on a substrate to be tested.

The investigation of the failure background of the substrate to be tested mainly comprises the following steps: recording data of a failure site; the failure investigation report comprises failure phenomena, investigation process, sample treatment and conclusion and the like; historical failure records of the multi-layer LTCC substrate of the type; the production condition of the multilayer LTCC substrate of the production batch is recorded, and the quality assurance condition is recorded.

And secondly, primarily confirming the failure of the substrate to be tested.

External inspection, including preferably with a stereomicroscope under illumination conditions and at a magnification, is performed to check for failure-related anomalies. And secondly, carrying out electrical performance test on the substrate to be tested, wherein the electrical performance test has the following three modes generally, different test methods are selected according to different failure modes of the multilayer LTCC substrate, and the principle is that the original failure mode is not changed and the original failure degree is not increased. Performing function test by adopting a similar line with a failure sample; and performing comparison test between test points by using other suitable instruments such as a graphic instrument and the like.

And then designing a scheme for detecting the failure of the substrate to be detected.

Before failure detection, different detection schemes need to be formulated according to failure conditions of different substrates to be detected, and detection is performed according to the formulated schemes.

And after a scheme for completing failure detection is formulated, detecting the substrate to be detected.

In some embodiments, a first test is performed on the substrate to be tested, wherein the first test may be a test performed using a flying probe test on-off device. The flying probe test on-off instrument is a test performed by using a probe that can be moved arbitrarily on the front and back surfaces of a substrate to be tested according to a network logic relationship of the substrate to be tested, as shown in a test flow chart of the flying probe test on-off instrument in fig. 2. And applying certain voltage and current to the probe by using the flying probe test on-off instrument to detect all lines in the network number in the substrate to be detected, so as to obtain a detection result. And according to the display data of the flying probe test on-off instrument, the network on-off condition of the substrate to be tested can be obtained. The network on-off condition mainly comprises the following steps: on, off, short, and insulated. Generally, the network number without failure refers to: two ports in the network are conducted, and two ports between the networks are insulated. If the two ports in the network are open or the two ports between the networks are short, the network is detected as a failure network, and the network number of the network is the failure network number. It should be noted that, before the test, the flying probe test on-off instrument sets a preset value for the test scheme of the substrate to be tested, so that the specific failure network number can be determined by comparing the test data of the flying probe test on-off instrument with the preset value.

Illustratively, the test modes may include an open circuit/conduction test and a short circuit/insulation test. And respectively carrying out open circuit/conduction test and short circuit/insulation test on the circuits in all network numbers, and then testing a first resistance value and a second resistance value corresponding to the target network number by the flying probe test on-off instrument. And comparing the preset open circuit valve resistance value with the first resistance value and the preset insulation valve resistance value with the second resistance value to determine the failure network number.

Specifically, the open circuit/conduction test is to prick two probes on different pads in the same network number, and obtain a first resistance value through testing the two different pads. It should be noted that, before testing, a tester may preset a preset open-circuit valve resistance value according to different types of substrates to be tested. When the first resistance value is smaller than the resistance value of the open-circuit valve, the circuit between the two tested bonding pads in the network number is conducted, and the test is qualified. When the first resistance value is larger than the resistance value of the open valve, the circuit between the two tested bonding pads in the network number is an open circuit. At the moment, the flying probe test on-off instrument system displays that the state of the network is open circuit or on in the open circuit/on test result by comparing the first resistance value with the resistance value of the open circuit valve.

And the short circuit/insulation test is to prick two probes on the bonding pads in different network numbers, and test the bonding pads in the two different network numbers through the probes to obtain a second resistance value. It should be noted that, before testing, a tester may preset a preset resistance value of the insulation valve according to different types of substrates to be tested. When the second resistance value is larger than the resistance value of the insulating valve, the insulating state is shown between the different network numbers to be tested. When the second resistance value is smaller than the resistance value of the insulating valve, the short circuit state is shown between different network numbers to be tested. At the moment, the flying probe test on-off instrument system can display that the state between each pair of networks is short circuit or insulation in a short circuit/insulation test result through comparing the second resistance value with the resistance value of the insulation valve.

In addition, the capacitance test can be used as a supplement to an open circuit/conduction test and a short circuit/insulation test, the conductivity of some networks is not ideal, misjudgment can occur in the resistance test, and extra information related to the network impedance can be obtained by performing the capacitance test. The capacitance test needs to master the detailed information of the tested network, whether the network fails or not is judged according to the consistency with a design value or a theoretical value by testing an actual capacitance value, the capacitance value is displayed by the test result of the capacitance value for the reference of a tester, and qualitative criteria are not provided.

Finally, after the flying probe test on-off instrument performs the above test on the lines in all network numbers in the substrate to be tested, different test results are displayed on the flying probe test on-off instrument. And determining that the circuit in the network number has an open circuit or a short circuit as long as the test result has a short circuit or an open circuit, wherein the network number is a failure network number, and the failure network number of the substrate to be tested can be determined.

And step S120, carrying out second detection on the line in the failure network number, and determining the failure position of the substrate to be detected.

And determining the failure position by carrying out second detection on the line in the failure network number.

In some embodiments, the second detection may employ an impedance testing system to test lines within the target failure network number to obtain the scattering parameters of the target failure network number. And determining the failure position in the target failure network number according to the obtained scattering parameters of the target failure network number. Wherein, the target failure network number is any failure network number in all failure network numbers.

As shown in fig. 3, the impedance testing system includes a vector network analyzer 310, an impedance testing circuit 320, and a coaxial connection line 330, where the impedance testing circuit 320 includes a probe stage 321 and a radio frequency probe, and specifically, the radio frequency probe may be an SMA contact radio frequency probe. The substrate to be tested is mounted on the probe station 321, and is connected to one end of the vector network analyzer 310 and one end of the probe station 321 through the coaxial connection line 330, so that the rf probe is placed at a certain position of the substrate to be tested.

Before the vector network analyzer is used for testing, radio frequency signal calibration needs to be performed on the end face of the probe station, and the SOLT method is used for calibration. And after the calibration is finished, placing the substrate to be tested on the lower part of the radio frequency probe on the probe station. And then applying a radio frequency signal to the substrate to be tested through a radio frequency signal source of the network analyzer, reflecting if impedance is discontinuous in the signal transmission process, finding discontinuous points such as short circuit, open circuit, via holes, wiring width change and the like in the failure network signal to be tested through judging the reflection phenomenon, obtaining the specific failure position, and realizing lossless failure positioning.

Specifically, firstly, a radio frequency signal source of the vector network analyzer is used for applying a radio frequency signal to a line in a target failure network number of a substrate to be detected, after the transmission of the radio frequency signal on the line in the target failure network number on the substrate to be detected is completed, a reflected signal is transmitted to a receiver of the vector network analyzer, and the receiver can obtain a scattering parameter of the target failure network number through an incident signal and the reflected signal. And the position corresponding to the peak point of the S11 curve in the scattering parameters is the failure position in the target failure network number. And after the failure positions of the target failure network numbers are determined, adjusting the positions of the radio frequency probes, sequentially testing the lines in the next target failure network number, and determining the corresponding failure positions in all the failure network numbers through the positions of peak points of S11 curves in the scattering parameters.

During signal transmission, if the impedance of the transmission line changes, part of energy of the radio frequency signal is reflected, and the rest of energy continues to propagate. Therefore, the impedance change can be calculated by knowing the amplitude of the transmitted wave and measuring the amplitude of the reflected wave. At the same time, the position of the impedance change can be calculated by measuring the time interval from a certain position of the transmitted wave to the transmission point.

In the process of transmitting radio frequency signals on a line in a target failure network number on a substrate to be tested, according to a transmission line theory, a corresponding relation exists between the reflection coefficient increment and the impedance increment at a certain position on the transmission line:

where f is the reflection coefficient, Z is the transmission line impedance, and az is the amount of change in impedance at a location. The signal obtained by the bidirectional receiver is subjected to time domain analysis, so that the impedance change condition of each part of the radio frequency transmission line can be obtained, and the reflection coefficient f and the S11 parameter measured by the vector network analyzer have a single-value corresponding relation: s₁₁20lg Γ. The impedance of the transmission line varies with the position of the substrate to be measured, and is a function of the signal transmission distance. By utilizing the time domain measurement function of the vector network analyzer, after a radio frequency signal source of the vector network analyzer sends a row of radio frequency signals, the reflection coefficient calculated by the receiver is a function of time, and as the radio frequency signals are transmitted on a transmission line at the speed of light, the impedance and the reflection coefficient establish a time domain corresponding relation, and the impedance value of each position can be obtained according to the reflection coefficient of each position.

In practice, however, the failure location can be determined by only determining the position of the transmission line impedance where the abnormal sudden change exists, and not by integrating the impedance value of each position. In the application, the failure position can be determined only by determining the position of the peak point of the S11 curve, and the impedance value does not need to be calculated one by one. And (3) substituting the time value t of the peak point position of the S11 curve into an L ═ ct formula, wherein c is the speed of light in the transmission medium, and the distance from the failure position to the test end face can be obtained.

The position that the peak point of S11 curve corresponds is determined to the position that became invalid through directly this application embodiment, and need not through loaded down with trivial details conversion and the impedance of calculating each position to the position that becomes invalid is determined fast, has improved the efficiency that detects greatly.

In some embodiments, in order to determine the failure mode, after the vector network analyzer obtains an S11 curve, the S11 curve is uploaded to an upper computer, a physical layer test system PLTS is installed in the upper computer, the PLTS performs frequency domain to time domain conversion on the received S11 parameters, the S11 curve in the scattering parameters is converted into impedances corresponding to various positions, the impedances corresponding to the peak positions of the S11 curve are the impedances of the failure positions, and the occurring failure mode can be simply judged through the magnitude of the impedance change of the failure positions and the capacitive and inductive changes of the impedances.

And S130, analyzing the failure position to determine the failure mechanism of the substrate to be tested.

In some embodiments, after determining the failure location by the above method, the failure location may be inspected from the top, side, or other suitable angle of the substrate to be tested by an X-ray radiography or real-time X-ray inspection apparatus, to determine and verify internal lead short circuits, open circuits, package internal redundancy, structural abnormalities, and the like associated with the failure at an excessive temperature or an electrical stress, and to determine the failure mechanism of the substrate to be tested according to the inspection result.

In some embodiments, after determining the failure position by the above method, the failure condition of the failure position can also be observed by using an acoustic scanning microscope (SAM) method. The principle of acoustic scanning is that a voltage is applied to an ultrasonic probe, high-frequency ultrasonic waves are generated by the probe, reach a sample through a coupling medium, penetrate through a sample interface, and finally form an ultrasonic scanning image according to a received signal (transmission or reflection). When ultrasonic waves pass through different media, reflected waves with large amplitude can appear at interfaces with defective devices or poor bonding due to the difference of acoustic impedance, and particularly when defects such as delamination and cracks exist, the air in the delamination can cause the ultrasonic waves to be reflected 100% and to be in reverse phase. The failure mechanism of the substrate to be tested can be determined from the scanned image.

In some embodiments, after the failure position is determined by the above method, the inside of the failure position may also be inspected by using a magnetic microscopic defect positioning technique or a synchronous thermal emission analysis technique, and the failure mechanism of the substrate to be tested is determined according to the inspection result.

Of course, the failure positions can also be analyzed by adopting the above methods at the same time to determine the failure mechanism of the substrate to be tested.

The invention provides a nondestructive failure detection method of a multilayer low-temperature co-fired ceramic substrate, which comprises the steps of firstly testing the communication relation of an electrical network on a substrate to be tested, and determining a failure network number; secondly, determining a specific failure position by performing a second test on a line in the failure network number and utilizing the characteristic that the impedance of the transmission line is changed due to the failure of the multilayer LTCC substrate; after failure location is completed, the failure mechanism is determined by employing a variety of different means. The detection method can quickly and accurately determine the failure position and is convenient for further determining the failure mechanism.

It should be understood that, the sequence numbers of the steps in the foregoing embodiments do not imply an execution sequence, and the execution sequence of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present invention; although the present invention has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; such modifications and substitutions do not substantially depart from the spirit and scope of the embodiments of the present invention, and are intended to be included within the scope of the present invention.