CN117214647A

CN117214647A - Electronic device detection method, apparatus, device, storage medium, and program product

Info

Publication number: CN117214647A
Application number: CN202311343806.6A
Authority: CN
Inventors: 彭超; 雷志锋; 张战刚; 何玉娟; 马腾
Original assignee: China Electronic Product Reliability and Environmental Testing Research Institute
Current assignee: China Electronic Product Reliability and Environmental Testing Research Institute
Priority date: 2023-10-17
Filing date: 2023-10-17
Publication date: 2023-12-12

Abstract

The present application relates to an electronic device inspection method, apparatus, device, storage medium, and program product. The method comprises the following steps: determining an electronic device to be tested; the back surface of the electronic device to be tested comprises an undamaged electrode structure and a back surface exposed area, wherein the electrode structure of the back surface exposed area is damaged; after a preset pressurizing device is controlled to input bias voltage to the electrode structure, monitoring real-time current corresponding to the electronic device to be tested; controlling a laser device to emit laser to the back exposure area, and monitoring whether the real-time current changes or not to obtain a monitoring result; and determining whether a radiation effect sensitive area exists in the back surface exposed area according to the monitoring result. The method can be used for effectively detecting the power device.

Description

Electronic device detection method, apparatus, device, storage medium, and program product

Technical Field

The present application relates to the field of semiconductor integrated circuit manufacturing technology, and in particular, to an electronic device inspection method, apparatus, device, storage medium, and program product.

Background

The power semiconductor device is a key device of all power electronic systems, and the application field of the power semiconductor device covers various industrial equipment, power locomotives, aerospace systems, smart grids, automobile electronic systems and various consumer electronic equipment. The inspection of power semiconductor devices is a critical step in the maintenance and management of electrical and electronic equipment, which helps ensure the reliability, performance and safety of the equipment.

In the related art, the exposed area of the semiconductor device to be tested can be further detected by opening the hole in the package of the semiconductor device to make the exposed area of the semiconductor device to be tested leak out.

However, the above-described technique has a problem in that the power device cannot be effectively detected.

Disclosure of Invention

In view of the foregoing, it is desirable to provide an electronic device detection method, apparatus, device, storage medium, and program product that can effectively detect a power device.

In a first aspect, the present application provides a method for detecting an electronic device, the method comprising:

determining an electronic device to be tested; the back surface of the electronic device to be tested comprises an undamaged electrode structure and a back surface exposed area, wherein the electrode structure of the back surface exposed area is damaged;

after a preset pressurizing device is controlled to input bias voltage to an electrode structure, monitoring real-time current corresponding to an electronic device to be tested;

controlling a laser device to emit laser to the back exposure area, and monitoring whether the real-time current changes or not to obtain a monitoring result;

and determining whether the radiation effect sensitive area exists in the back surface exposed area according to the monitoring result.

In one embodiment, the controlling the laser device to emit laser light to the back surface exposed area includes:

Adjusting the relative position relationship between the laser device and the back exposed area;

the laser device is controlled to emit laser light vertically to the back surface exposed region.

In one embodiment, the monitoring whether the real-time current changes to obtain the monitoring result includes:

controlling the mobile station to move along a first direction of the back exposure area according to a preset first step length, and monitoring and obtaining first currents of all first subareas in the back exposure area; an electronic device to be tested is fixed on the mobile station, and the back exposed area faces the emitting end of the laser device;

and monitoring whether each first current changes or not to obtain a monitoring result.

In one embodiment, the monitoring whether each first current changes to obtain a monitoring result includes:

controlling the mobile station to move along a second direction of the back exposure area according to a preset second step length, and monitoring and obtaining second currents of each second sub-area in the back exposure area;

and monitoring whether each first current changes or not and whether each second current changes or not, and obtaining a monitoring result.

In one embodiment, the determining whether the radiation effect sensitive area exists in the back surface exposed area according to the monitoring result includes:

If any one of the first currents changes, determining the first sub-area corresponding to the first current as a radiation effect sensitive area;

and if any one of the second currents changes, determining the second sub-region corresponding to the second current as a radiation effect sensitive region.

In one embodiment, the method further comprises:

determining a back surface exposed area in the back surface of the electronic device to be tested;

wherein a ratio of an area of the back surface exposed region to an area of the back surface is greater than a first threshold value and less than a second threshold value.

In a second aspect, the present application also provides an electronic device testing apparatus, including:

the sample preparation module is used for determining an electronic device to be tested; the back surface of the electronic device to be tested comprises an undamaged electrode structure and a back surface exposed area, wherein the electrode structure of the back surface exposed area is damaged;

the pressurizing module is used for monitoring the real-time current corresponding to the electronic device to be tested after the preset pressurizing device is controlled to input the bias voltage to the electrode structure;

the monitoring module is used for controlling the laser device to emit laser to the back exposure area and monitoring whether the real-time current changes or not to obtain a monitoring result;

and the judging module is used for determining whether the radiation effect sensitive area exists in the back surface exposed area according to the monitoring result.

In a third aspect, the present application also provides a computer device comprising a memory and a processor, the memory storing a computer program, the processor implementing the following steps when executing the computer program:

In a fourth aspect, the present application also provides a computer readable storage medium having stored thereon a computer program which when executed by a processor performs the steps of:

In a fifth aspect, the application also provides a computer program product comprising a computer program which, when executed by a processor, performs the steps of:

According to the electronic device detection method, the device, the equipment, the storage medium and the program product, the electronic device to be detected is determined, the preset pressurizing device is controlled to input the bias voltage to the electrode structure, the real-time current corresponding to the electronic device to be detected is monitored, the laser device is controlled to emit laser to the back exposure area, whether the real-time current changes or not is monitored, a monitoring result is obtained, and finally whether the radiation effect sensitive area exists in the back exposure area or not is determined according to the monitoring result. The back surface of the electronic device to be tested comprises an undamaged electrode structure and a back surface exposed area, wherein the electrode structure of the back surface exposed area is damaged. In the method, the laser device can be controlled to emit laser to the back exposure area of the electronic device to be detected, the real-time current of the electronic device to be detected is monitored by adding bias voltage to the electrode structure of the electronic device to be detected, the real-time current of the electronic device to be detected can be changed when the laser irradiates the radiation effect sensitive area of the back exposure area, whether the radiation effect sensitive area of the electronic device to be detected exists can be determined by monitoring whether the current is changed, meanwhile, the radiation effect sensitive area of the back exposure area characterizes the radiation effect sensitive area of the electronic device to be detected, and therefore, the radiation effect sensitive area of the electronic device to be detected can be accurately positioned according to the position of the laser irradiated in the back exposure area when the real-time current is changed by monitoring whether the corresponding real-time current is changed, and further effective detection of the power device is realized.

Drawings

In order to more clearly illustrate the embodiments of the present application or the technical solutions in the related art, the drawings that are required to be used in the embodiments or the related technical descriptions will be briefly described, and it is apparent that the drawings in the following description are only some embodiments of the present application, and other drawings may be obtained according to the drawings without inventive effort for those skilled in the art.

FIG. 1 is an internal block diagram of a computer device in one embodiment;

FIG. 2 is a flow chart of a method of electronic device inspection in one embodiment;

FIG. 3 is a schematic diagram of another embodiment of a partially exposed patterning of the back side of a device;

FIG. 4 is a graph of detection results using conventional detection techniques in another embodiment;

FIG. 5 is a graph of the results of another embodiment using a sample with a partially exposed backside;

FIG. 6 is a flow chart of a method for detecting an electronic device according to another embodiment;

FIG. 7 is a flow chart of a method of detecting an electronic device according to another embodiment;

FIG. 8 is a flow chart of a method of detecting an electronic device according to another embodiment;

FIG. 9 is a flow chart of a method of detecting an electronic device according to another embodiment;

Fig. 10 is a block diagram of an electronic device inspection apparatus in one embodiment.

Detailed Description

The present application will be described in further detail with reference to the drawings and examples, in order to make the objects, technical solutions and advantages of the present application more apparent. It should be understood that the specific embodiments described herein are for purposes of illustration only and are not intended to limit the scope of the application.

The power semiconductor device is a key device of all power electronic systems, and the application field of the power semiconductor device covers various industrial equipment, power locomotives, aerospace systems, smart grids, automobile electronic systems and various consumer electronic equipment. As a core device in the field of energy control, it is estimated that at least 50% of the world's electricity consumption is controlled by power devices. The large-scale commercial application of power devices represented by silicon-based and silicon carbide-based has led to the development of power electronic systems. Typically, power devices are of a vertical configuration with electrodes on both the front and back sides and a large area of metal coverage. The large area of metal can block the emission of optical signals inside the device and the incidence of external optical signals, which can present difficulties for detection and analysis based on optical signals. For example: (1) After the power device fails, a micro light microscope (Emission Microscope, EMMI), a light beam induced resistance change (Optical Beam Induced Resistance Change, OBIRCH) and other means can be used to locate the failure position of the device. EMMI is the detection of photons emitted from a failure location within the device in the powered state to effect failure localization. The working principle of the OBIRCH is that the surface of a device is scanned by utilizing a laser beam under constant voltage, part of energy of the laser beam is converted into heat energy, if a metal interconnection line has defects, the temperature at the defect cannot be rapidly conducted and dispersed through the metal line, the temperature at the defect is accumulated and increased, the resistance of the metal line and the current change are further caused, and the defect position is positioned through the correspondence between a change area and the scanning position of the laser beam. The large area of metal on the front and back of the power device can block EMMI light emission and OBIRCH laser beam incidence, resulting in undesirable detection effects. (2) When the power device is used in space, high-energy particles are incident to cause burning or gate penetrating failure of the power device. The incidence of the space radiation particles can be simulated in a laser injection mode, so that weak links in the power device are defined. But the large area metal on the front and back of the power device blocks the incidence of the laser light, rendering the test impossible.

The first prior art discloses a method for preparing a universal laser back irradiation test sample, which comprises the steps of firstly selecting a universal tube shell according to the number of pins of a chip to be tested; determining a tube shell perforating scheme according to the size of the chip to be tested and the distribution of the sensitive areas, and perforating the universal tube shell according to the perforating scheme; bonding the bare chip into the selected perforated universal tube shell to expose all sensitive areas of the chip to be tested; and finally, carrying out laser scanning test on all sensitive areas of the chip to be tested. The method simplifies the sample preparation method, solves the problem that laser cannot penetrate through the metal layer to develop laser single particle test research on the device, and provides support and guidance for developing laser back irradiation test of the integrated circuit. The method aims to obtain a device to be tested which exposes a chip at a specific position, and the technical route is that after a general chip tube shell is selected, the tube shell is perforated, and then the chip to be tested is bonded to the tube shell after perforation, so that the position to be tested on the chip is exposed. However, the actual sample is usually a commercial sample already packaged, so that the universal package cannot be selected and the bare chip is bonded again. The above technical route may be applicable to products in self-research or development processes, and is difficult to implement for mature commercial products.

The second prior art relates to a preparation method of a flip chip detection sample. The method comprises the following steps: pretreatment: soaking the flip chip packaging integrated circuit to be detected by using an organic solvent, and prying the packaging shell open to expose the back surface of the flip chip; fixing: fixing the flip chip packaged integrated circuit on a fixture by using hot melt wax; grinding: and grinding and thinning the back surface of the exposed flip chip, monitoring the distance from the surface of the integrated circuit substrate packaged by the flip chip to the back surface of the flip chip, and stopping grinding when the thickness of the chip is a preset thickness, thus obtaining a flip chip detection sample. The method can thin the flip chip to a proper thickness according to the requirement, so as to meet the thickness requirement that infrared and near infrared light penetrates through the silicon chip when the back surface defect is positioned, ensure that pins of a circuit are intact, namely the electrical property is good, and ensure the requirement that voltage bias is required to be applied when the back surface light emission defect is detected. The existing sample preparation technology aims at a flip chip, and the back substrate of the flip chip mainly plays a role of mechanical support and has no electrical connection, so that the substrate can be thinned to a specified thickness by an integral back grinding method. However, for the vertical power device, the back substrate is usually an electrode structure, and the whole electrical connection of the power device can be damaged by adopting the structure, so that the device cannot load voltage and cannot carry out relevant detection analysis.

In summary, embodiments of the present application provide a method, apparatus, device, storage medium and program product for detecting an electronic device, which can solve the above technical problems.

The electronic device detection method provided by the embodiment of the application can be applied to detection equipment, wherein the detection equipment can be a numerical control machine tool comprising a mobile platform, and particularly can comprise a grinding table, a power supply, a laser, a mobile platform, a microscope, an oscilloscope and a control terminal, wherein the grinding table is used for preparing a device sample; the power supply is used for providing stable voltage for the device; the laser is used for emitting laser; the movable platform is used for fixing the device sample and driving the device sample to move; the microscope is used for focusing the laser; the oscilloscope is used for monitoring data; the emitting end of the laser faces the microscope, the movable platform is positioned below the microscope and the laser, and laser emitted by the laser can be focused by the microscope and is incident to the surface of the movable platform; the control terminal can be computer equipment and is mainly used for adjusting power output parameters, controlling power output voltage, setting mobile parameters of the mobile platform and controlling the mobile platform to move, and is also used for monitoring data acquired by the oscilloscope and displaying the monitored data, or can also be used for displaying the monitored data in a mode of inputting the detected data.

The control terminal may be a computer device, and the computer device may be a terminal or a server, and the internal structure of the control terminal may be as shown in fig. 1, for example. The computer device includes a processor, a memory, a communication interface, a display screen, and an input device connected by a system bus. Wherein the processor of the computer device is configured to provide computing and control capabilities. The memory of the computer device includes a non-volatile storage medium and an internal memory. The non-volatile storage medium stores an operating system and a computer program. The internal memory provides an environment for the operation of the operating system and computer programs in the non-volatile storage media. The communication interface of the computer device is used for carrying out wired or wireless communication with an external terminal, and the wireless mode can be realized through WIFI, an operator network, NFC (near field communication) or other technologies. The computer program is executed by a processor to implement a method of electronic device detection. The display screen of the computer equipment can be a liquid crystal display screen or an electronic ink display screen, and the input device of the computer equipment can be a touch layer covered on the display screen, can also be keys, a track ball or a touch pad arranged on the shell of the computer equipment, and can also be an external keyboard, a touch pad or a mouse and the like.

It will be appreciated by those skilled in the art that the architecture shown in fig. 1 is merely a block diagram of some of the architecture relevant to the present inventive arrangements and is not limiting as to the computer device to which the present inventive arrangements may be implemented, as a particular computer device may include more or less components than those shown, or may be combined with some components, or may have a different arrangement of components.

In one embodiment, an electronic device testing method is provided, and this embodiment relates to a specific process of how to test an electronic device to be tested, as shown in fig. 2, and taking the application of the method to the above testing device as an example, the method may include the following steps:

s202, determining an electronic device to be tested; the back surface of the electronic device to be tested comprises an undamaged electrode structure and a back surface exposed area, wherein the electrode structure of the back surface exposed area is damaged.

The electronic device to be tested refers to a processed semiconductor device, and the semiconductor device can be a power device, such as a vertical power device, wherein the front surface structure of the vertical power device generally comprises an active area of the device, which is a key area for current flow and power control, and one or more control electrodes for controlling the on or off state of the device, and metal connections for connecting the device to a circuit board or other electronic components, and the connections can be soldering, bonding pads, bonding wires or other forms of connection; the back side structure of a vertical power device typically includes bottom electrodes for connecting the device to a circuit board or other electronic component, which are typically made of metal to ensure good electrical connection. In addition, the back surface exposed area of the electronic device to be tested comprises the whole active area structure of the power device, and the back surface exposed area can enable the internal optical signals of the device to be emitted and the external optical signals to be incident into the device.

The electronic device to be tested is a processed semiconductor device, taking a vertical power device as an example, optionally, the following steps A1-A4 may be adopted in a specific processing procedure:

step A1, wrapping a vertical power device to be treated by liquid resin, and after the resin is solidified, fixedly sealing the power device;

and step A2, placing the back of the device subjected to the solid sealing on a grinding table downwards for grinding, as shown in fig. 3 (left diagram). During grinding, the back of the device forms a certain small angle with the grinding table；

Step A3, polishing the area exposed by grinding, wherein the polishing mode can adopt Chemical Mechanical Polishing (CMP);

and step A4, removing the solid sealing resin, and optionally removing the residual solid sealing resin on the surface of the vertical power device in a chemical dissolution mode.

Further, when the back surface of the sealing device is ground, the back surface of the device forms a certain small angle with the grinding table，/>The range of values of (2) may be between 10 and 30 degrees. In addition, the termination condition of the polishing may be to stop the polishing when 50% or more of the back metal of the metal portion of the back side of the device is removed (but it must be ensured that the back metal is not completely removed). If the metal on the back of the device is removed completely, the bottom electrode of the power device is included on the back of the device, and the whole electrical connection of the power device is destroyed by the complete removal, so that the device cannot be connected to voltage.

Taking a vertical power device as an example, after the vertical power device is processed, the electronic device to be tested can be obtained, and as an alternative embodiment, the back surface of the electronic device to be tested and a back surface exposure area in the back surface are determined; wherein a ratio of an area of the back surface exposed region to an area of the back surface is greater than a first threshold value and less than a second threshold value.

The back surface of the electronic device to be tested comprises an area where the bottom electrode structure is not worn and a back surface exposed area where the bottom electrode structure is worn; meanwhile, the area of the back surface exposed area is larger than the first threshold, where the first threshold may be 50% or other percentage value, which is not limited in this embodiment, and the area of the back surface exposed area is smaller than the second threshold, where the second threshold may be 100% or other percentage value, which is not limited in this embodiment. The value of the second threshold is not smaller than the value of the first threshold.

As for the back surface of the electronic device to be tested and the back surface exposed area in the back surface, the back surface of the electronic device to be tested and the back surface exposed area in the back surface are observed by a microscope, and as shown in fig. 3 (right view), the exposed area and the back surface metal which is not completely removed can be observed from fig. 3 (right view).

In order to verify the effectiveness of detecting the back exposed area of the electronic device to be detected, EMMI or OBIRCH detection is performed on the electronic device to be detected by adopting the existing conventional technology. Specifically, a specific bias voltage is loaded to the power device, and detection is performed from the front side of the device. Since the front surface covers a large area of metal wiring, light emission signals of micro-damage positions under the metal are shielded, so that the micro-damage positions are difficult to capture, as shown in fig. 4, as can be seen from fig. 4, the light signals are detected only in the active regions at the metal gaps, because the gaps are not covered by the metal, and the light signals cannot be emitted because the front active regions are covered by the metal in other regions. In addition, when the detection is performed from the back of the device, the optical signals emitted from the micro-damage area can be detected in the area where the back metal is stripped, namely, the back exposed area, so that the defect is positioned, as shown in fig. 5, a large number of tiny optical signals can be seen from fig. 5, and the positions where the optical signals appear are the positions where the electronic devices fail. Of course, the optical signal can be smoothly detected in the back exposed area because part of the back metal is removed, if the front side of the device is also ground in the same grinding manner, the metal structure of the front side of the device is removed, so that the bias voltage cannot be smoothly connected into the electronic device, and thus related detection cannot be performed. Accordingly, the relevant inspection from the back surface exposed area of the electronic device under test is reliable and effective.

Specifically, the electronic device is processed and ground, so that an exposed area appears on the back surface of the electronic device, and the electronic device with the back surface comprising the exposed area is determined as the electronic device to be tested.

S204, after the preset pressurizing device is controlled to input bias voltage to the electrode structure, the real-time current corresponding to the electronic device to be tested is monitored.

The preset pressurizing device is used for providing a voltage for the electronic device to be tested, for example, may be a high-voltage power supply device or may be a power supply device such as a switching power supply, which is not particularly limited in this embodiment, so long as a stable voltage can be provided for the electronic device to be tested. In addition, when the electronic device to be tested is a vertical power device, in an initial case, the power device is normally biased in a reverse off state, that is, a state in which current cannot flow through the device. When the power device is connected with a power supply, the anode and the cathode of the power supply can be connected with two ends or three ends of the power device respectively, for example, for devices with two ends such as a diode and the like, the front anode is connected with the cathode of the power supply, and the back cathode is connected with positive high voltage (connected with the anode); when three-terminal devices such as MOSFET are connected, the positive source electrode and the grid electrode are connected to the negative electrode of the power supply, and the positive high voltage is applied to the back drain electrode (connected to the positive electrode).

For the electronic device to be tested, when the preset pressurizing device is controlled to input the bias voltage, the back surface of the electronic device to be tested comprises an undamaged electrode structure, so that the positive electrode of the power supply is required to be connected to the back electrode structure of the electronic device to be tested, and the negative electrode of the power supply is required to be connected to the front electrode of the electronic device to be tested, so that the electronic device to be tested is ensured to be in a working state. In addition, the magnitude of the bias voltage may be selected to be 40% of the rated voltage of the electronic device to be tested in the initial state, or may be another value, which is not particularly limited in this embodiment.

After the preset pressurizing device is controlled to input the bias voltage to the electrode structure, the ammeter or the oscilloscope can be adopted to monitor the real-time current of the electronic device to be tested, and the current data of the electronic device to be tested can be observed.

Specifically, after the electronic device to be tested is obtained, the preset pressurizing device is controlled to input the bias voltage to the undamaged electrode structure in the back surface of the electronic device to be tested, and then the real-time current corresponding to the electronic device to be tested is monitored.

S206, controlling the laser device to emit laser to the back surface exposure area, and monitoring whether the real-time current changes or not to obtain a monitoring result.

The laser device includes a laser and a microscope, and the laser may be a solid laser or a semiconductor laser, which is not particularly limited in this embodiment. The laser can emit laser with certain energy for irradiating the back exposed area of the electronic device to be tested, and the laser emitted by the laser needs to be focused by a microscope during irradiation, so as to control the laser to emit laser to the back exposed area.

The laser beam emitted from the laser device can only irradiate a small area of the back surface exposed area, and the size of the irradiated area is related to the beam spot size of the laser.

The laser emitted by the laser needs to preset laser parameters, so that the laser irradiates the back exposed area of the electronic device to be tested with the laser with selected wavelength, pulse width and energy. Wherein, the wavelength is selected: the wavelength selective stress ensures that the laser energy produces a photogenerated carrier effect inside the device. For example, to ensure that photoionization can be generated in a silicon-based device and the silicon-based device has enough incidence depth, the wavelength of the selected pulse laser source is between 800nm and 1100nm, a 1064nm solid state laser can be adopted, and for a wide bandgap semiconductor device, a laser with shorter wavelength, such as a solid state laser with the wavelength of 532nm, is adopted; selection of pulse width: because the process of generating ionization transient pulse by the incidence of the space high-energy particles is about 1ps, the laser source with the pulse width of the pulse laser source in picosecond order can be selected, or other laser sources with different pulse widths can be selected, but the laser pulse width is required to be smaller than 30ns in principle; energy selection: the laser energy is typically chosen to be of the order of nJ (nanojoules).

When the laser irradiates the back exposure area of the electronic device to be detected, the current of the electronic device can be influenced by the photo-generated carrier effect generated in the device, specifically, after the metal material of the back exposure area is irradiated by the laser, local electrons can be increased, and then the current of the electronic device to be detected is increased, so that whether the real-time current of the electronic device to be detected changes or not can be monitored, and a monitoring result can be obtained.

Specifically, after the bias voltage is input to the back electrode structure of the electronic device to be tested, the laser device can be controlled to irradiate the back exposed area with the selected laser, and the real-time current of the electronic device to be tested is monitored to obtain the monitoring result of the electronic device to be tested while the laser is irradiated.

And S208, determining whether a radiation effect sensitive area exists in the back surface exposed area according to the monitoring result.

The monitoring result refers to the current change condition of the electronic device to be tested when the laser irradiates the back exposure area, when the current in the monitoring result keeps unchanged, the current indicates that the radiation effect sensitive area does not exist in the back exposure area irradiated by the laser, and if the current in the monitoring result changes, such as fluctuation, current increase and the like, the current indicates that the radiation effect sensitive area exists in the back exposure area irradiated by the laser. The initial value refers to the current of the electronic device to be tested when the laser irradiation is not performed on the back surface exposure area. In addition, the radiation effect area of the back exposed area of the electronic device to be tested refers to an area where radiation particles are incident to easily induce the electronic device to be tested to be damaged and fail.

Specifically, after the monitoring result is obtained, whether the radiation effect sensitive area exists in the back surface exposed area is determined according to the monitoring result, if the current in the monitoring result changes, the radiation effect sensitive area exists in the back surface exposed area, and if the current in the monitoring result does not change, the radiation effect sensitive area does not exist in the back surface exposed area.

In the electronic device detection method, after the electronic device to be detected is determined, the preset pressurizing device is controlled to input the bias voltage to the electrode structure, the real-time current corresponding to the electronic device to be detected is monitored, then the laser device is controlled to emit laser to the back exposure area, whether the real-time current changes is monitored, a monitoring result is obtained, and finally whether the radiation effect sensitive area exists in the back exposure area is determined according to the monitoring result. The back surface of the electronic device to be tested comprises an undamaged electrode structure and a back surface exposed area, wherein the electrode structure of the back surface exposed area is damaged. In the method, the laser device can be controlled to emit laser to the back exposure area of the electronic device to be detected, the real-time current of the electronic device to be detected is monitored by adding bias voltage to the electrode structure of the electronic device to be detected, the real-time current of the electronic device to be detected can be changed when the laser irradiates the radiation effect sensitive area of the back exposure area, whether the radiation effect sensitive area of the electronic device to be detected exists can be determined by monitoring whether the current is changed, meanwhile, the radiation effect sensitive area of the back exposure area characterizes the radiation effect sensitive area of the electronic device to be detected, and therefore, the radiation effect sensitive area of the electronic device to be detected can be accurately positioned according to the position of the laser irradiated in the back exposure area when the real-time current is changed by monitoring whether the corresponding real-time current is changed, and further effective detection of the power device is realized. Further, a backside of the electronic device under test and a backside exposed region in the backside are determined. Wherein a ratio of an area of the back surface exposed region to an area of the back surface is greater than a first threshold value and less than a second threshold value. The area ratio of the exposed area on the back surface is limited, so that the whole active area structure and the electrical connection of the power device are not damaged, and meanwhile, the exposed area can ensure the emission of an optical signal inside the device and the incidence of an external optical signal, and the related detection analysis can be smoothly carried out.

The above-described embodiments have mentioned that the laser device may be controlled to emit laser light to the back-side exposed area, and the following embodiments describe one possible implementation of how the laser device may be controlled to emit laser light to the back-side exposed area.

In another embodiment, another method for detecting an electronic device is provided, and based on the above embodiment, as shown in fig. 6, the step S206 may include the following steps:

s302, adjusting the relative position relation between the laser device and the back surface exposure area.

The relative positional relationship between the laser device and the back surface exposure area may be such that the laser device is vertically opposite to the back surface exposure area, so that laser light emitted from the laser device may be vertically irradiated in the back surface exposure area.

In this step, when the positional relationship is adjusted, the electronic device to be measured may be moved and adjusted so that the back exposed area of the electronic device to be measured is opposite to the laser device, for example, a movable platform on which the electronic device to be measured is fixed may be moved, or the laser device may be moved, and the position of the laser device may be adjusted so that the positional relationship between the back exposed area of the electronic device to be measured and the laser device is achieved.

Specifically, the distance between the microscope and the electronic device to be tested is adjusted, so that laser is focused inside an active area of a back exposure area of the electronic device to be tested, and the laser emitted by the laser device can vertically enter the back exposure area.

S304, controlling the laser device to vertically emit laser light to the back surface exposed area.

After the relative position relation between the laser device and the back exposure area is adjusted, the laser is turned on, so that laser emitted by the laser is focused by the microscope and vertically enters the back exposure area.

In this embodiment, the laser device is controlled to emit laser light vertically to the back surface exposure region by adjusting the relative positional relationship between the laser device and the back surface exposure region. Here, the laser emitted by the laser device can be perpendicularly incident to the back exposure area by adjusting the relative position relationship between the laser device and the back exposure area, and the perpendicularly incident laser can ensure that the energy of the laser beam is concentrated in the beam area, so that the laser intensities received by all the back exposure areas are consistent, and the detection accuracy can be ensured.

The above embodiments refer to the fact that whether the real-time current is changed or not can be monitored, and the monitoring result is obtained, and the following embodiments describe a specific process how to obtain the monitoring result.

In another embodiment, as shown in fig. 7, another method for detecting an electronic device is provided, where the step S206 may include the following steps, based on the above embodiment:

S402, controlling the mobile station to move along a first direction of the back exposure area according to a preset first step length, and monitoring and obtaining first currents of all first sub-areas in the back exposure area; the mobile station is fixedly provided with an electronic device to be tested, and the back surface exposed area faces the emitting end of the laser device.

The mobile station is a three-dimensional mobile sample station capable of moving in three directions (X direction, Y direction and Z direction), an electronic device to be tested is fixed on the mobile station, the electronic device to be tested can be fixed on the mobile station by adopting a fixture, and an exposed area of the back of the electronic device to be tested faces upwards, namely, faces towards a transmitting end of the laser device. The first direction of the back surface exposure area may be the X-axis direction or the Y-axis direction of the mobile station, and this embodiment is not particularly limited. The first step length refers to a step length of a single movement of the mobile station along the first direction, and the setting of the step length is selected according to the size of the laser beam spot. For example, if the laser beam spot size is 5um, the step length is also selected to be 5um to ensure that the laser scan area can cover the entire backside exposed area of the electronic device under test. Of course, if the area of the back exposed area of the electronic device to be tested is large, the step length may be increased appropriately, which is not limited in this embodiment.

Further, the mobile station is controlled to move in a first direction according to a preset first step length, when the laser beam irradiates the back surface exposed area, the area irradiated by the laser beam spot size can be used as a first sub-area, and each step length is moved, one first sub-area corresponds to each step length. In addition, when the laser irradiates each first subarea of the back exposure area, the real-time current of the electronic device to be tested can be obtained through an ammeter or an oscilloscope and is recorded as first current, and each first subarea corresponds to the first current.

The initial movement position of the mobile station may be any position within the back surface exposed area, and this embodiment is not particularly limited. In addition, the movement along the first direction may be from left to right or from right to left along the X-axis direction if the movement is in the X-axis direction; the manner of movement in the Y-axis direction may be from top to bottom or from bottom to top along the Y-axis direction, and is not particularly limited in this embodiment.

Specifically, after the laser beam is vertically incident on the back exposure area, the mobile station fixed with the electronic device to be tested is controlled to move along the first direction of the back exposure area according to a preset first step length, each first sub-area is determined, and each step length is moved, the first current corresponding to the first sub-area is monitored, and then the first current corresponding to each first sub-area in the back exposure area of the electronic device to be tested is monitored and obtained.

S404, monitoring whether each first current changes or not to obtain a monitoring result.

In this step, whether each first current changes or not refers to whether the current corresponding to the electronic device to be tested changes or not when the back surface exposed area is not irradiated by the laser, which is specifically expressed as real-time current increase, and an oscilloscope can be used to observe the change condition of each first current, so as to obtain the monitoring result of the electronic device to be tested.

In this embodiment, the mobile station is controlled to move along the first direction of the back exposure area according to a preset first step length, and the first current of each first sub-area in the back exposure area is monitored and obtained, and then whether each first current changes is monitored, so that a monitoring result is obtained. The mobile station is fixedly provided with an electronic device to be tested, and the back surface exposed area faces the emitting end of the laser device. Here, since the monitoring is performed while the mobile station is controlled to move, the change condition of the first current of each first sub-region in the back surface exposure region can be obtained in real time, and by monitoring the change of the current, the possible defect or abnormal condition in the back surface exposure region can be identified.

The above examples refer to the possibility of monitoring whether each first current is changed or not, and the monitoring result is obtained, and the following examples describe another possible implementation of obtaining the monitoring result.

In another embodiment, as shown in fig. 8, another method for detecting an electronic device is provided, where the step S404 may include the following steps, based on the above embodiment:

s502, along a second direction of the back exposure area, controlling the mobile station to move according to a preset second step length, and monitoring and obtaining second currents of each second sub-area in the back exposure area.

The second direction of the back surface exposed area may be an X-axis direction or a Y-axis direction, but the second direction is different from the first direction, for example, when the first direction is the X-axis direction, the second direction is the Y-axis direction. In addition, the preset step length of the second step length is the same as the step length of the first step length.

Further, the second sub-areas are areas irradiated by the laser when the mobile station is controlled to move along the second direction, and each of the second sub-areas corresponds to a second current.

In this step, the moving stage may be controlled to move along the second direction of the back surface exposure area according to a preset second step length, and may alternate with the moving manner along the first direction in S402, for example, the moving may be performed first along the first direction and then along the second direction, so that the laser may scan all the back surface exposure area, or may be performed first along the second direction and then along the first direction, which is not limited specifically in this embodiment.

Specifically, the mobile station is controlled to move along a second direction of the back surface exposure area according to a preset second step length, and second currents of all second sub-areas in the back surface exposure area are obtained through monitoring.

S504, monitoring whether each first current changes and each second current changes, and obtaining a monitoring result.

In this step, the first current and the second current are monitored respectively, each of the first current and the second current corresponds to one of the first sub-region and one of the second sub-region respectively, a real-time current monitoring result of each of the first sub-region and the second sub-region is obtained, and further, whether a radiation effect sensitive region exists in the back exposed region or not can be determined according to the monitoring result, as an optional embodiment, if any one of the first currents changes, the first sub-region corresponding to the first current is determined to be the radiation effect sensitive region; and if any one of the second currents changes, determining the second sub-region corresponding to the second current as a radiation effect sensitive region.

The monitoring of whether the first current and the second current change may be performed synchronously or asynchronously with the laser scanning of the back surface exposure area, which is not particularly limited in this embodiment. If the current is synchronous, monitoring whether the real-time current changes when the laser scans one back exposure subarea by moving one step length, and if the current changes, determining the current laser scanning area as a radiation effect sensitive area; if the laser scanning is not synchronous, the mobile platform can be controlled to scan all the back exposure areas, current data corresponding to each moving step length is recorded and stored, after all the back exposure areas are scanned by the laser, all the current data are analyzed, the positions of the back exposure subareas corresponding to the laser scanning at the moment when the current data change are found, and then all the radiation effect sensitive areas are determined.

The first current and the second current are both values obtained under the same bias voltage, alternatively, the bias voltage can be adjusted gradually, for example, the bias voltage can be increased gradually, laser scanning can be performed on the electronic device to be tested again when the bias voltage is adjusted once, and corresponding current data under the current bias voltage is monitored, so that the monitoring result of the electronic device to be tested under different bias voltages can be obtained, the working state of the electronic device to be tested can be changed by different bias voltages, further, the electronic device to be tested can be detected more comprehensively under different working states, and the radiation effect sensitive area can be detected more accurately.

In this embodiment, the mobile station is controlled to move along the second direction of the back exposure area according to a preset second step length, and the second currents of each second sub-area in the back exposure area are obtained through monitoring, and then whether each first current changes and whether each second current changes are monitored, so that a monitoring result is obtained. The change condition of the second current of each second sub-region in the back surface exposure region can be obtained in real time, and the radiation effect sensitive region in the back surface exposure region can be comprehensively positioned by monitoring the change of the first current and the second current. Further, when determining whether the radiation effect sensitive area exists in the back exposed area according to the monitoring result, if any one of the first currents changes, determining the first sub-area corresponding to the first current as the radiation effect sensitive area, and if any one of the second currents changes, determining the second sub-area corresponding to the second current as the radiation effect sensitive area. The radiation effect sensitive area obtained by the corresponding relation determination is more accurate through the corresponding relation between the first current and the second current and the first subarea and the second subarea.

In the following, a detailed embodiment is given to illustrate the technical solution of the present application by taking the detection of a power device as an example, and on the basis of the above embodiment, as shown in fig. 9, the method may include the following steps:

s1, wrapping a device to be tested with liquid resin, and after the resin is solidified, fixedly sealing the power device;

s2, placing the back of the device after the fixation and encapsulation downwards on a grinding table for grinding, wherein a device sample and the grinding table form a certain small angle theta, such as 15 degrees, during grinding; the back metal is removed under the polishing termination condition of 50% or more (but it must be ensured that the back metal is not completely removed);

s3, polishing the area exposed by grinding in a chemical mechanical polishing mode, removing the residual sealing resin in a chemical dissolution mode, and finishing the sample preparation of the back surface part of the power device;

s4, fixing the exposed area on the back of the sample on a three-dimensional movable sample table through a clamp in a right-side-up horizontal manner;

s5, biasing the power device and monitoring current in real time, wherein for devices at two ends such as a diode and the like, the positive electrode of the front side is connected with the negative electrode, and the negative electrode of the back side is connected with positive high voltage;

s6, focusing laser with selected wavelength, pulse width and energy by a microscope, vertically incident to an exposed area on the back of the sample, and adjusting the distance between the microscope and the sample so that the laser is focused in an active area of the power device;

S7, setting the stepping length of the three-dimensional sample stage in the X-axis and Y-axis directions, and driving the device sample to move on an XY plane through the sample stage so as to enable the laser to scan all exposed areas on the back of the sample;

s8, if the power device fails under the irradiation of the laser in the specific area (the failure is shown as abnormal increase of the monitoring current in the X-axis or Y-axis direction), the area is a radiation effect sensitive area of the power device.

Based on the same inventive concept, the embodiment of the application also provides an electronic device detection device for realizing the above related electronic device detection method. The implementation of the solution provided by the device is similar to that described in the above method, so the specific limitations in the embodiments of the electronic device detection device or devices provided below can be referred to above for limitations of the electronic device detection method, and will not be repeated here

In one embodiment, as shown in fig. 10, there is provided an electronic device detecting apparatus including: sample preparation module, pressurization module, monitoring module, judgement module, wherein:

In another embodiment, another electronic device detecting apparatus is provided, where, on the basis of the above embodiment, the above monitoring module includes an adjusting unit and a control unit, where:

an adjusting unit for adjusting a relative positional relationship between the laser device and the back surface exposure region;

and the control unit is used for controlling the laser device to vertically emit laser to the back surface exposure area.

In another embodiment, another electronic device detecting apparatus is provided, where, on the basis of the above embodiment, the above monitoring module further includes a first scanning unit and a first monitoring unit, where:

the first scanning unit is used for controlling the mobile station to move along a first direction of the back exposure area according to a preset first step length and monitoring and obtaining first currents of all first sub-areas in the back exposure area; an electronic device to be tested is fixed on the mobile station, and the back exposed area faces the emitting end of the laser device;

The first monitoring unit is used for monitoring whether each first current changes or not to obtain a monitoring result.

Optionally, the first monitoring unit may include:

the second scanning subunit is used for controlling the mobile station to move along a second direction of the back exposure area according to a preset second step length and monitoring and obtaining second currents of all second sub-areas in the back exposure area;

and the second monitoring subunit is used for monitoring whether each first current changes and whether each second current changes to obtain a monitoring result.

In another embodiment, another electronic device detecting apparatus is provided, where, based on the above embodiment, the judging module includes a first judging unit and a second judging unit, where:

the first judging unit is used for determining that a first sub-area corresponding to the first current is a radiation effect sensitive area if any one of the first currents changes;

and the second judging unit is used for determining that the second subarea corresponding to the second current is a radiation effect sensitive area if any one of the second currents changes.

In another embodiment, another electronic device detecting apparatus is provided, which further includes a determining module based on the above embodiment, wherein:

A determining module, configured to determine a back surface of the electronic device to be tested and the back surface exposed area in the back surface; wherein a ratio of an area of the back surface exposed region to an area of the back surface is greater than a first threshold and less than a second threshold.

The above-described respective modules in the electronic device inspection apparatus may be implemented in whole or in part by software, hardware, or a combination thereof. The above modules may be embedded in hardware or may be independent of a processor in the computer device, or may be stored in software in a memory in the computer device, so that the processor may call and execute operations corresponding to the above modules.

In one embodiment, a computer device is provided comprising a memory and a processor, the memory having stored therein a computer program, the processor when executing the computer program performing the steps of:

determining an electronic device to be tested; the back surface of the electronic device to be tested comprises an undamaged electrode structure and a back surface exposed area, wherein the electrode structure of the back surface exposed area is damaged; after a preset pressurizing device is controlled to input bias voltage to an electrode structure, monitoring real-time current corresponding to an electronic device to be tested; controlling a laser device to emit laser to the back exposure area, and monitoring whether the real-time current changes or not to obtain a monitoring result; and determining whether the radiation effect sensitive area exists in the back surface exposed area according to the monitoring result.

In one embodiment, the processor when executing the computer program further performs the steps of:

adjusting the relative position relationship between the laser device and the back exposed area; the laser device is controlled to emit laser light vertically to the back surface exposed region.

controlling the mobile station to move along a first direction of the back exposure area according to a preset first step length, and monitoring and obtaining first currents of all first subareas in the back exposure area; an electronic device to be tested is fixed on the mobile station, and the back exposed area faces the emitting end of the laser device; and monitoring whether each first current changes or not to obtain a monitoring result.

controlling the mobile station to move along a second direction of the back exposure area according to a preset second step length, and monitoring and obtaining second currents of each second sub-area in the back exposure area; and monitoring whether each first current changes or not and whether each second current changes or not, and obtaining a monitoring result.

If any one of the first currents changes, determining the first sub-area corresponding to the first current as a radiation effect sensitive area; and if any one of the second currents changes, determining the second sub-region corresponding to the second current as a radiation effect sensitive region.

determining a back surface exposed area in the back surface of the electronic device to be tested; wherein a ratio of an area of the back surface exposed region to an area of the back surface is greater than a first threshold value and less than a second threshold value.

In one embodiment, a computer readable storage medium is provided having a computer program stored thereon, which when executed by a processor, performs the steps of:

In one embodiment, the computer program when executed by the processor further performs the steps of:

In one embodiment, a computer program product is provided comprising a computer program which, when executed by a processor, performs the steps of:

It should be noted that, the data related to the present application (including, but not limited to, data for analysis, stored data, displayed data, etc.) are all data that are fully authorized by each party, and the collection, use and processing of the related data are required to meet the related regulations.

Those skilled in the art will appreciate that implementing all or part of the above described methods may be accomplished by way of a computer program stored on a non-transitory computer readable storage medium, which when executed, may comprise the steps of the embodiments of the methods described above. Any reference to memory, database, or other medium used in embodiments provided herein may include at least one of non-volatile and volatile memory. The nonvolatile Memory may include Read-Only Memory (ROM), magnetic tape, floppy disk, flash Memory, optical Memory, high density embedded nonvolatile Memory, resistive random access Memory (ReRAM), magnetic random access Memory (Magnetoresistive Random Access Memory, MRAM), ferroelectric Memory (Ferroelectric Random Access Memory, FRAM), phase change Memory (Phase Change Memory, PCM), graphene Memory, and the like. Volatile memory can include random access memory (Random Access Memory, RAM) or external cache memory, and the like. By way of illustration, and not limitation, RAM can be in the form of a variety of forms, such as static random access memory (Static Random Access Memory, SRAM) or dynamic random access memory (Dynamic Random Access Memory, DRAM), and the like. The databases referred to in the embodiments provided herein may include at least one of a relational database and a non-relational database. The non-relational database may include, but is not limited to, a blockchain-based distributed database, and the like. The processor referred to in the embodiments provided in the present application may be a general-purpose processor, a central processing unit, a graphics processor, a digital signal processor, a programmable logic unit, a data processing logic unit based on quantum computing, or the like, but is not limited thereto.

The technical features of the above embodiments may be arbitrarily combined, and all possible combinations of the technical features in the above embodiments are not described for brevity of description, however, as long as there is no contradiction between the combinations of the technical features, they should be considered as the scope of the description.

The foregoing examples illustrate only a few embodiments of the application and are described in detail herein without thereby limiting the scope of the application. It should be noted that it will be apparent to those skilled in the art that several variations and modifications can be made without departing from the spirit of the application, which are all within the scope of the application. Accordingly, the scope of the application should be assessed as that of the appended claims.

Claims

1. A method of electronic device inspection, the method comprising:

after a preset pressurizing device is controlled to input bias voltage to the electrode structure, monitoring real-time current corresponding to the electronic device to be tested;

and determining whether a radiation effect sensitive area exists in the back surface exposed area according to the monitoring result.

2. The method of claim 1, wherein the controlling the laser device to emit laser light toward the back-side exposed region comprises:

adjusting the relative positional relationship between the laser device and the back surface exposed region;

and controlling the laser device to vertically emit laser to the back surface exposed area.

3. The method according to claim 1 or 2, wherein monitoring whether the real-time current changes or not to obtain a monitoring result comprises:

controlling a mobile station to move along a first direction of the back exposure area according to a preset first step length, and monitoring and obtaining first currents of all first sub-areas in the back exposure area; the electronic device to be tested is fixed on the mobile station, and the back surface exposed area faces the emitting end of the laser device;

4. A method according to claim 3, wherein said monitoring whether each of said first currents changes or not to obtain a monitoring result comprises:

and monitoring whether each first current changes or not and whether each second current changes or not, so as to obtain a monitoring result.

5. The method of claim 4, wherein said determining whether the radiation effect sensitive area is present in the backside exposed area based on the monitoring result comprises:

if any one of the first currents changes, determining a first sub-region corresponding to the first current as a radiation effect sensitive region;

6. The method according to claim 1, wherein the method further comprises:

determining a back side of the electronic device under test and the back side exposed area in the back side;

Wherein a ratio of an area of the back surface exposed region to an area of the back surface is greater than a first threshold and less than a second threshold.

7. An electronic device inspection apparatus, the apparatus comprising:

8. A computer device comprising a memory and a processor, the memory storing a computer program, characterized in that the processor implements the steps of the method of any of claims 1 to 6 when the computer program is executed.

9. A computer readable storage medium, on which a computer program is stored, characterized in that the computer program, when being executed by a processor, implements the steps of the method of any of claims 1 to 6.

10. A computer program product comprising a computer program, characterized in that the computer program, when being executed by a processor, implements the steps of the method of any of claims 1 to 6.