Ultrasonic probe and radiator integrated device and method for measuring temperature and pressure of crimping type power device

Abstract

The invention relates to an ultrasonic probe and radiator integrated device and method for measuring the temperature and pressure of a crimping type power device, and belongs to the technical field of semiconductor devices. A water-cooling radiator of the integrated device is attached to the electrode surface of the multi-chip crimping type power device, a plurality of probe grooves used for installing ultrasonic probes are formed in the water-cooling radiator, the distribution mode of the probe grooves is determined according to the position distribution of chips in the crimping type power device, and when the ultrasonic probes are installed in the probe grooves, the ultrasonic probes are fixed in the probe grooves. An ultrasonic transmitting and receiving part of the ultrasonic probe is opposite to a corresponding chip in the crimping type power device and is attached to an electrode surface of the crimping type power device; according to the method, the pressure and the steady-state junction temperature of the crimping type power device are measured through the relation curve between the pressure and the reflection coefficient of the crimping type power device and the relation curve between the steady-state junction temperature fluctuation and the pressure fluctuation. The ultrasonic probe base can effectively reduce the influence of the existing ultrasonic probe base on the heat dissipation performance of the crimping type power device.

Description

Technical Field

[0001] The invention belongs to the technical field of semiconductor devices, and relates to an integrated device and method of an ultrasonic probe and a heat sink for measuring the temperature and pressure of a press-fit power device. Background Art

[0002] Press-fit power devices are now widely used in flexible DC transmission projects because of their advantages such as easier parallel packaging on a large scale, easy series use, double-sided heat dissipation, and failure short circuit. However, press-fit power devices use external pressure to maintain the electrical connection between the chip and the electrode. In order to meet the high current requirements of flexible DC equipment, dozens of power chip modules are often packaged in parallel. Due to the microscopic unevenness of the contact interface between the chip and other materials, the work tolerance of the components in the device during processing, and the imbalance of the clamp pressurization, the internal chip electrical and thermal force distribution of the press-fit power device is uneven during operation, affecting the operational reliability of the press-fit power device.

[0003] In flexible DC commutation equipment, press-fit power devices and water-cooled heat sinks are often stacked in sequence to form a valve section, and the existing method of using ultrasonic technology to measure the pressure distribution of the chip inside the press-fit power device requires the addition of an additional measuring base to place the ultrasonic probe, so as to ensure that the ultrasonic probe is aligned with the vertical center of the chip. For example, the patent "A pressure distribution test device and test method for press-fit power semiconductor devices" with application number CN202211439668.7 discloses: a pressure measurement device, an ultrasonic transmitting and receiving sensor, and a processor are installed on the base, and the base is in contact with the press-fit power semiconductor device to provide good current carrying capacity under working conditions. However, this type of measuring device has a certain thickness, which prolongs the heat dissipation path of the press-fit power device during operation, increases the thermal resistance between the power chip and the water-cooled heat sink, reduces the heat dissipation efficiency of the device, affects the heat dissipation performance of the device, and causes the long-term operation reliability of the device to deteriorate. Summary of the invention

[0004] In view of this, an object of the present invention is to provide an integrated device and method of an ultrasonic probe and a heat sink for measuring temperature and pressure of a press-fit power device.

[0005] In order to achieve the above object, the present invention provides the following technical solutions:

[0006] An integrated device of an ultrasonic probe and a heat sink for measuring the temperature and pressure of a press-fit power device, the integrated device at least comprising: a press-fit power device, a water-cooled heat sink and an ultrasonic probe, wherein the water-cooled heat sink is bonded to the electrode surface of a multi-chip press-fit power device,

[0007] A plurality of probe grooves for installing ultrasonic probes are provided in the water-cooled radiator. The distribution of the probe grooves is determined according to the chip position distribution inside the press-fit power device. When the ultrasonic probe is installed in the probe groove, the ultrasonic transmitting and receiving parts of the ultrasonic probe are aligned with the corresponding chip in the press-fit power device and fit with the electrode surface of the press-fit power device.

[0008] The ultrasonic probe measures the real-time pressure of the press-fit power device through the relationship curve between the pressure and the reflection coefficient of the press-fit power device, and measures the steady-state junction temperature of each sub-module of the press-fit power device through the relationship curve between the steady-state junction temperature fluctuation and the pressure fluctuation.

[0009] Furthermore, the relationship curve between pressure and reflection coefficient is expressed as:

[0010] F=a1·R 3 +a2·R 2 +a3·R+a4

[0011] Wherein, a1, a2, a3, and a4 are data fitting values, R represents the ultrasonic reflection coefficient of the contact surface of the first reflection of the ultrasonic probe, and F represents the pressure of the press-fit power device.

[0012] Furthermore, the relationship curve between steady-state junction temperature fluctuation and pressure fluctuation is expressed as:

[0013] ΔT j =b·ΔF

[0014] b=c1·F 2 +c2·F+c3

[0015] Among them, c1, c2, c3 are data fitting values, b is the calculated value related to the initial pressure, ΔF represents the pressure fluctuation, which is the difference between the pressure value corresponding to the highest junction temperature and the initial pressure, ΔT j is the steady-state junction temperature fluctuation.

[0016] Furthermore, a probe fixing spring for fixing the ultrasonic probe is also provided in the probe groove; each probe groove is connected to a signal line groove for placing the probe signal line of the ultrasonic probe, and multiple signal line grooves converge and extend to the side of the water-cooled radiator.

[0017] Furthermore, the diameter and depth of the probe groove match the height and width of the ultrasonic probe, and the diameter and depth of the signal line groove match the line diameter of the probe signal line.

[0018] Furthermore, a plurality of positioning pins are provided on the water-cooled radiator, and a plurality of positioning holes are provided on the press-fit power device, and the positioning pins are inserted into the positioning holes in a manner of fitting with each other.

[0019] Furthermore, a water inlet is provided on the side of the water-cooling radiator.

[0020] The present invention also proposes a method for integrating an ultrasonic probe and a heat sink for measuring the temperature and pressure of a crimped power device. The method for integrating the ultrasonic probe and the heat sink for measuring the temperature and pressure of a crimped power device comprises the following steps:

[0021] S1: Obtain the package structure, size and internal chip distribution layout of the press-fit power device to be tested;

[0022] S2: Measure the chip size of the press-fit power device and select a piezoelectric ultrasonic probe that matches the chip size;

[0023] S3: Obtaining the size and internal flow channel space position information of the water-cooled heat sink of the press-fit power device to be tested;

[0024] S4: According to the internal chip distribution layout of the press-fit power device and the size information of the ultrasonic probe, the depth and radius of the groove of the water-cooled heat sink are designed, and the position corresponds to the position of the chip of the press-fit power device;

[0025] S5: According to the diameter of the ultrasonic probe signal line and the actual installation position of the water-cooled radiator, a groove for the ultrasonic probe signal line is regularly designed on the surface of the water-cooled radiator close to the electrode side of the press-fit power device, and the installation is completed;

[0026] S6: using a single-chip press-fit power device submodule to calibrate the ultrasonic reflection coefficient R of the contact surface where the first reflection occurs under different pressures F, and establishing a pressure-reflection coefficient relationship curve of the press-fit power device through data fitting at a certain pressure interval within a preset pressure range;

[0027] S7: Calibrate the steady-state junction temperature fluctuation and pressure fluctuation of a single-chip press-fit power device submodule when working under the same initial pressure, steady-state junction temperature fluctuation ΔT j is the difference between the maximum junction temperature and the initial junction temperature during operation. The pressure fluctuation is the difference ΔF between the pressure value corresponding to the maximum junction temperature and the initial pressure. The relationship curve between the steady-state junction temperature fluctuation and the pressure fluctuation under different initial pressure conditions is measured.

[0028] The beneficial effects of the present invention are:

[0029] 1) The present invention integrates an ultrasonic probe on a crimped power device water-cooled heat sink, which can conduct current and heat flow normally, and the crimped water-cooled heat sink with the integrated ultrasonic probe can still maintain good heat dissipation performance, which solves the limitation of the existing device performance degradation caused by the increased thickness of the ultrasonic measurement base, and can ensure good measurement accuracy.

[0030] 2) The integrated design method of the ultrasonic probe and heat sink involved in the present invention is applicable to any crimped power device water-cooled heat sink and has good repeatability. The ultrasonic probe is directly integrated into the surface groove of the crimped water-cooled heat sink without adding additional equipment, and the machining cost of the crimped water-cooled heat sink is low, thereby improving the economy of the ultrasonic measurement technology.

[0031] Other advantages, objectives and features of the present invention will be described in the following description to some extent, and to some extent, will be obvious to those skilled in the art based on the following examination and study, or can be taught from the practice of the present invention. The objectives and other advantages of the present invention can be realized and obtained through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] In order to make the purpose, technical solutions and advantages of the present invention more clear, the present invention will be described in detail below in conjunction with the accompanying drawings, wherein:

[0033] Figure 1 It is a schematic diagram of the overall simplified structure of the integrated device of the present invention;

[0034] Figure 2 Schematic diagram of chip distribution inside a press-fit power device according to an embodiment;

[0035] Figure 3 It is a schematic diagram of the maximum junction temperature simulation comparison results of the integrated device of the present invention, the device with an ultrasonic measurement base, and a multi-chip press-fit power device under normal conditions.

[0036] Figure numerals: 1- water-cooled radiator; 2- ultrasonic probe; 3- probe fixing spring; 4- probe signal line; 5- positioning pin; 6- probe groove; 7- signal line slot; 8- water inlet; 9- crimped power device; 10- positioning hole. DETAILED DESCRIPTION

[0037] The following describes the embodiments of the present invention by specific examples, and those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that the illustrations provided in the following embodiments only illustrate the basic concept of the present invention in a schematic manner, and the following embodiments and features in the embodiments can be combined with each other without conflict.

[0038] Among them, the drawings are only used for illustrative explanations, and they only represent schematic diagrams rather than actual pictures, and should not be understood as limitations on the present invention. In order to better illustrate the embodiments of the present invention, some parts of the drawings may be omitted, enlarged or reduced, and do not represent the size of actual products. For those skilled in the art, it is understandable that some well-known structures and their descriptions in the drawings may be omitted.

[0039] The same or similar numbers in the drawings of the embodiments of the present invention correspond to the same or similar parts; in the description of the present invention, it should be understood that if the terms "upper", "lower", "left", "right", "front", "rear", etc. indicate the orientation or position relationship, they are based on the orientation or position relationship shown in the drawings, which is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation. Therefore, the terms describing the position relationship in the drawings are only used for illustrative purposes and cannot be understood as limiting the present invention. For ordinary technicians in this field, the specific meanings of the above terms can be understood according to specific circumstances.

[0040] See also Figure 1 to Figure 3 , which is an integrated device and method of an ultrasonic probe and a heat sink for measuring the temperature and pressure of a press-fit power device.

[0041] Example

[0042] This embodiment proposes an integrated device of an ultrasonic probe and a heat sink for measuring the temperature and pressure of a press-fit power device. Figure 1 As shown, it specifically includes: a crimped power device water-cooled heat sink 1, a piezoelectric ultrasonic probe 2, a probe fixing spring 3, a probe signal line 4, a positioning pin 5, a probe groove 6, a signal line groove 7, a water inlet of a water-cooled heat sink 8, a multi-chip crimped power device 9, and a crimped power device positioning hole 10.

[0043] according to Figure 2 The internal chip layout of the press-fit power device shown in the figure is that a probe groove 6 is machined on the surface of one side of the press-fit water-cooled heat sink 1 close to the power device electrode, which is used to place the ultrasonic probe 2 and the probe fixing spring 3. The depth of the probe groove 6 is slightly greater than the height of the ultrasonic probe 2, and the processing position of the probe groove 6 is vertically consistent with the internal chip layout structure of the press-fit power device 5. The piezoelectric ultrasonic probe 2 is used to transmit and receive ultrasonic waves. The probe fixing spring 3 is placed in the probe groove 2, and is tightly coupled with the piezoelectric ultrasonic probe 2, and ensures that the ultrasonic probe 2 is tightly fitted with the electrode surface of the press-fit power device 9.

[0044] The ultrasonic probe 2 measures the real-time pressure of the press-fit power device through the relationship curve between the pressure of the press-fit power device and the reflection coefficient of the ultrasonic probe 2, wherein the relationship curve between the pressure and the reflection coefficient is expressed as:

[0045] F=a1·R 3 +a2·R 2 +a3·R+a4

[0046] Among them, a1, a2, a3, and a4 are data fitting values, R represents the ultrasonic reflection coefficient of the contact surface at the first reflection, and F represents the pressure of the press-fit power device. This relationship curve can monitor the pressure of each sub-module inside the press-fit power device when it is working by measuring the reflection coefficient of the press-fit power device at the first reflection under working conditions.

[0047] The ultrasonic probe 2 measures the steady-state junction temperature of each sub-module of the press-fit power device through the relationship curve between the steady-state junction temperature fluctuation and the pressure fluctuation, wherein the relationship curve between the steady-state junction temperature fluctuation and the pressure fluctuation is expressed as:

[0048] ΔT j =b·ΔF

[0049] b=c1·F 2 +c2·F+c3

[0050] Among them, c1, c2, c3 are data fitting values, b is the calculated value related to the initial pressure, ΔF represents the pressure fluctuation, which is the difference between the pressure value corresponding to the highest junction temperature and the initial pressure, ΔT j It is the steady-state junction temperature fluctuation; combined with the fitted pressure and reflection coefficient relationship curve, the pressure fluctuation when the press-fit power device is working can be measured, and the steady-state junction temperature of each sub-module of the device when it is working can be monitored.

[0051] In this embodiment, the probe signal line 4 is used to transmit the electrical signals for generating and receiving ultrasound and is placed in the signal line slot 7 .

[0052] In this embodiment, the processing position of the probe groove 6 on the surface of the water-cooled heat sink 1 is consistent with the internal chip layout structure of the press-fit power device 9 .

[0053] In this embodiment, the diameter and depth of the probe groove 6 of the water-cooled radiator 1 are slightly larger than the height of the piezoelectric ultrasonic probe 2 .

[0054] In this embodiment, the diameter and depth of the signal wire groove 7 on the surface of the water-cooled radiator 1 are slightly larger than the wire diameter of the probe signal wire 4 .

[0055] In this embodiment, the probe groove 6 and the signal wire groove 7 of the water-cooled radiator 1 have a symmetrical structure, the outlet of the signal wire groove 7 is located at the water inlet 8 of the water-cooled radiator, and the outlet of the signal wire groove on the other side is located at a symmetrical position.

[0056] In this embodiment, the positioning pin 5 of the water-cooled radiator 1 is consistent in size with the positioning hole 10 of the press-fit power device, so that the press-fit power device 9 is tightly coupled to the water-cooled radiator 1 .

[0057] In this embodiment, Figure 2 Taking the chip layout shown in the figure as an example, a method for integrating an ultrasonic probe and a heat sink for temperature and pressure measurement of a press-fit power device is proposed, and the design steps for integrating an ultrasonic probe and a heat sink for temperature-pressure measurement of the device are described:

[0058] S1: Obtain the package structure, size and internal chip distribution layout of the press-fit power device to be tested.

[0059] S2: Measure the chip size of the press-fit power device and select a piezoelectric ultrasonic probe with appropriate chip size and height.

[0060] S3: Obtain the size and internal flow channel space position information of the water-cooled heat sink of the press-fit power device to be tested.

[0061] S4: According to the internal chip distribution layout of the press-fit power device and the size information of the ultrasonic probe, the depth and radius of the groove of the water-cooled heat sink are designed, and the position corresponds to the position of the chip of the press-fit power device.

[0062] S5: Based on the diameter of the ultrasonic probe signal line and the actual installation position of the water-cooled radiator, a groove for the ultrasonic probe signal line is regularly designed on the surface of the water-cooled radiator close to the electrode of the press-fit power device;

[0063] S6: Using a single-chip press-fit power device submodule to calibrate the ultrasonic reflection coefficient R of the contact surface where the first reflection occurs under different pressure F conditions, the reflection coefficient R is the ratio of the first reflection wave amplitude to the incident wave amplitude, the pressure range under different pressure conditions is 100N-2000N, and the interval is 100N. The pressure-reflection coefficient relationship curve of the press-fit power device is established through data fitting;

[0064] S7: Calibrate the steady-state junction temperature fluctuation and pressure fluctuation of a single-chip press-fit power device submodule when working under the same initial pressure, steady-state junction temperature fluctuation ΔT j is the difference between the maximum junction temperature and the initial junction temperature during operation. The pressure fluctuation is the difference ΔF between the pressure value corresponding to the maximum junction temperature and the initial pressure. The relationship curve between the steady-state junction temperature fluctuation and the pressure fluctuation under different initial pressure conditions is measured.

[0065] In order to reflect the optimization effect of the present invention, the maximum junction temperature of the internal chips of the multi-chip press-fit power device containing the ultrasonic measurement base, the integrated device of the present invention and the normal state is compared by using COMSOL multi-physics field simulation software. Figure 3 shown.

[0066] Depend on Figure 3 It can be seen that the maximum junction temperature of the internal chip of the press-bonded power device in the integrated device of the ultrasonic probe and heat sink for temperature-pressure measurement of multi-chip press-bonded power devices in the embodiment of the present invention is 63.3°C, which is 2.3°C lower than the maximum internal junction temperature of the press-bonded power device in the existing additional ultrasonic measurement base, and the impact on the maximum internal junction temperature of the press-bonded power device under normal heat dissipation conditions is within 4.5%, which proves that the integrated design of the ultrasonic probe and heat sink for temperature-pressure measurement of multi-chip press-bonded power devices does not have much impact on the heat dissipation performance of the press-bonded power devices, and has better advantages than the additional ultrasonic measurement base.

[0067] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solution of the present invention can be modified or replaced by equivalents without departing from the purpose and scope of the technical solution, which should be included in the scope of the claims of the present invention.

Claims

1. An integrated device of an ultrasonic probe and a heat sink for measuring temperature and pressure of a press-fit power device, characterized in that: The integrated device comprises at least: a press-fit power device (9), a water-cooled heat sink (1) and an ultrasonic probe (2), wherein the water-cooled heat sink (1) is in contact with the electrode surface of the press-fit power device (9), wherein: The water-cooled heat sink (1) is provided with a plurality of probe grooves (6) for installing the ultrasonic probe (2); the distribution of the probe grooves (6) is determined according to the chip position distribution inside the press-fit power device (9); when the ultrasonic probe (2) is installed in the probe groove (6), the ultrasonic transmitting and receiving parts of the ultrasonic probe (2) are aligned with the corresponding chip in the press-fit power device (9), and are in contact with the electrode surface of the press-fit power device (9); The ultrasonic probe (2) measures the real-time pressure of the press-fit power device (9) through a relationship curve between the pressure and the reflection coefficient of the press-fit power device (9), and measures the steady-state junction temperature of each sub-module of the press-fit power device (9) through a relationship curve between steady-state junction temperature fluctuation and pressure fluctuation.

2. The ultrasonic probe and heat sink integrated device for measuring temperature and pressure of a press-fit power device according to claim 1, characterized in that: The relationship curve between pressure and reflection coefficient is expressed as: <h2 style=";text-align:left;direction:ltr">F=a1·R<h2 style=";text-align:left;direction:ltr"> 3 <h2 style=";text-align:left;direction:ltr"> +a2·R<h2 style=";text-align:left;direction:ltr"> 2 <h2 style=";text-align:left;direction:ltr"> +a3·R+a4 Wherein, a1, a2, a3, and a4 are data fitting values, R represents the ultrasonic reflection coefficient of the contact surface of the first reflection of the ultrasonic probe (2), and F represents the pressure of the press-fit power device (9).

3. The ultrasonic probe and heat sink integrated device for measuring temperature and pressure of a press-fit power device according to claim 2, characterized in that: The relationship curve between steady-state junction temperature fluctuation and pressure fluctuation is expressed as: ΔT j =b·ΔF b=c1·F 2 +c2·F+c3 Among them, c1, c2, c3 are data fitting values, b is the calculated value related to the initial pressure, ΔF represents the pressure fluctuation, which is the difference between the pressure value corresponding to the highest junction temperature and the initial pressure, ΔT j is the steady-state junction temperature fluctuation.

4. The ultrasonic probe and heat sink integrated device for measuring temperature and pressure of a press-fit power device according to claim 1, characterized in that: A probe fixing spring (3) for fixing the ultrasonic probe (2) is also provided in the probe groove (6); each of the probe grooves (6) is connected to a signal line groove (7) for accommodating a probe signal line (4) of the ultrasonic probe (2); a plurality of the signal line grooves (7) converge and extend to the side of the water-cooled radiator (1).

5. The ultrasonic probe and heat sink integrated device for measuring temperature and pressure of a press-fit power device according to claim 4, characterized in that: The diameter and depth of the probe groove (6) match the height and width of the ultrasonic probe (2), and the diameter and depth of the signal line groove (7) match the line diameter of the probe signal line (4).

6. The ultrasonic probe and heat sink integrated device for measuring temperature and pressure of a press-fit power device according to claim 1, characterized in that: The water-cooled radiator (1) is provided with a plurality of positioning pins (5), the press-fit power device (9) is provided with a plurality of positioning holes (10), and the positioning pins (5) are inserted into the positioning holes (10) in a manner of fitting each other.

7. The ultrasonic probe and heat sink integrated device for measuring temperature and pressure of a press-fit power device according to claim 1, characterized in that: A water inlet (8) is provided on the side of the water-cooling radiator (1).

8. A method for integrating an ultrasonic probe and a heat sink for measuring temperature and pressure of a press-fit power device, characterized in that: The integration method for manufacturing an integrated device of an ultrasonic probe and a heat sink for measuring temperature and pressure of a press-fit power device as described in any one of claims 1 to 7 comprises the following steps: S1: Obtaining the packaging structure, size and internal chip distribution layout of the press-fit power device (9) to be tested; S2: measuring the chip size of the press-fit power device (9) and selecting a piezoelectric ultrasonic probe (2) that matches the chip size; S3: Obtaining the size and internal flow channel space position information of the water cooling heat sink (1) of the press-fit power device (9) to be tested; S4: According to the internal chip distribution layout of the press-fit power device (9) and the size information of the ultrasonic probe (2), the groove depth and radius of the water-cooled heat sink (1) are designed, and the position corresponds to the chip position of the press-fit power device (9); S5: Based on the wire diameter of the ultrasonic probe (2) signal wire and the actual installation position of the water-cooled heat sink (1), a wire groove for the ultrasonic probe (2) signal wire is regularly designed on the surface of the water-cooled heat sink (1) close to the electrode side of the press-fit power device (9), and the installation is completed; S6: using the single-chip press-fit power device (9) submodule to calibrate the ultrasonic reflection coefficient R of the contact surface where the first reflection occurs under different pressure F conditions, and establishing a pressure-reflection coefficient relationship curve of the press-fit power device (9) by data fitting at a certain pressure interval within a preset pressure range; S7: Calibrate the steady-state junction temperature fluctuation and pressure fluctuation of the sub-module of the single-chip press-fit power device (9) when working under the same initial pressure, the steady-state junction temperature fluctuation ΔT j is the difference between the maximum junction temperature and the initial junction temperature during operation. The pressure fluctuation is the difference ΔF between the pressure value corresponding to the maximum junction temperature and the initial pressure. The relationship curve between the steady-state junction temperature fluctuation and the pressure fluctuation under different initial pressure conditions is measured.

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