Transient thermal resistance curve optimization method for structure analysis of TSV interposer heat dissipation performance

Abstract

This invention provides a structural analysis method for optimizing the heat dissipation performance of a TSV adapter plate using transient thermal resistance curves. The method includes: preparing TSV adapter plates with different center-point spacings for TSV structural units; testing the breakdown voltage curves of the TSV adapter plates; encapsulating diode chips on the TSV adapter plates to obtain diode devices with different center-point spacings for the TSV structural units; using the transient thermal resistance method to test the differential structure function curves of the diode devices to obtain the relationship between the center-point spacing of the TSV structural units and the thermal resistance parameter; and determining the optimal range of center-point spacing for the TSV structural units based on the breakdown voltage curves and thermal resistance curves of the TSV adapter plates. This invention isolates the heat dissipation performance of the TSV adapter plate from the heat dissipation performance of the diode devices using the transient thermal resistance method. Combined with the insulation performance of the TSV adapter plate, it determines the safe spacing range of the center points for the TSV structural units, solving the problem that traditional methods cannot experimentally quantify the impact of the density of through-silicon vias (TSVs) within the TSV adapter plate on the heat dissipation and insulation performance of the diode devices.

Description

Technical Field

[0001] This invention pertains to semiconductor detection technology, specifically relating to a structural analysis method for optimizing the heat dissipation performance of TSV adapter boards using transient thermal resistance curves. Background Technology

[0002] To ensure the reliability of semiconductor devices used in aerospace applications, the chips must operate within a specific temperature range. When the junction temperature of the chip reaches a critical point, the lifespan of the semiconductor device will be significantly shortened or even fail. With the miniaturization of electronic products, heat-dissipating TSV (Through Silicon Via) adapter technology is currently the primary method to effectively improve the heat dissipation efficiency of semiconductor chips, achieving efficient heat transfer from the chip to the package. While increasing the density of through-silicon vias (TSVs) in the TSV adapter can improve the overall heat dissipation efficiency of the device, the improvement becomes less significant once the TSV density reaches a critical point. Furthermore, excessively high TSV density increases the mechanical and thermal stress within the silicon wafer and may cause breakdown failures between the silicon wafer and the metal filling layer in the TSVs, severely impacting device reliability. Therefore, while increasing the TSV density of the TSV adapter, its insulation performance must also be considered.

[0003] Currently, the heat dissipation performance of TSV adapter boards is mainly evaluated through simulation and traditional temperature measurement methods.

[0004] (1) The simulation method first establishes finite element models of TSVs with different through-silicon via densities, and then applies thermal stress to the TSV models to obtain the effect of through-silicon via density on the heat dissipation performance of the TSV adapter. However, the simulation results differ significantly from the actual heat dissipation performance of the TSV adapter, and cannot effectively guide the fabrication and packaging process of the TSV adapter.

[0005] (2) In the traditional thermal resistance method, a heat source and a temperature measuring point T1 are installed on one side of the TSV adapter board, and a temperature measuring point T2 is installed on the other side. First, by changing the power P of the heat source, a series of varying temperature measuring points T1 and T2 are obtained. Then, the thermal resistance of the TSV adapter board is characterized by the ratio of the temperature difference between the two measuring points to the power P of the heat source. However, the power of the heat source and the actual power of the packaged chip differ significantly in the traditional thermal resistance method, and the environmental conditions of a one-dimensional heat dissipation path are not met. The measurement error is large, and it can only qualitatively determine the relative magnitude of the thermal resistance of the TSV adapter board. It cannot quantitatively analyze the influence of the through-silicon via density on the thermal resistance of the TSV adapter board, nor can it accurately analyze the influence of the through-silicon via density on the heat dissipation efficiency of the device.

[0006] To quantify the impact of TSV density on the heat dissipation and insulation performance of semiconductor devices from an experimental perspective, this invention employs the transient thermal resistance method to isolate the heat dissipation performance of the TSV adapter from the heat dissipation performance of the semiconductor device. Combined with the insulation performance of the TSV adapter, the safe spacing range of the center point of the TSV structural unit is determined, thus solving the problem that traditional methods cannot quantify the impact of TSV density on the heat dissipation and insulation performance of semiconductor devices from an experimental perspective. Summary of the Invention

[0007] The purpose of this invention is to provide a structural analysis method for optimizing the heat dissipation performance of TSV adapters using transient thermal resistance curves, thereby solving the problem that traditional methods cannot quantify the impact of the density of through-silicon vias (TSVs) within the TSV adapter on the heat dissipation and insulation performance of semiconductor devices from an experimental perspective.

[0008] To achieve the above objectives, this invention provides a structural analysis method for optimizing the heat dissipation performance of a TSV adapter board using transient thermal resistance curves. The method includes: preparing TSV adapter boards with different center-point spacings for TSV structural units; testing the breakdown voltage curve of the TSV adapter board; encapsulating diode chips on the TSV adapter board to obtain diode devices with different center-point spacings for TSV structural units; using the transient thermal resistance method to test the differential structure function curve of the diode devices to obtain the relationship between the center-point spacing of the TSV structural units and the thermal resistance parameter; and determining the optimal range of center-point spacing for the TSV structural units based on the breakdown voltage curve and thermal resistance curve of the TSV adapter board.

[0009] The above-mentioned structural analysis method for optimizing the heat dissipation performance of TSV adapter plates based on transient thermal resistance curves, wherein the preparation of TSV adapter plates with different center point spacings of TSV structural units includes:

[0010] Dry etching of silicon wafers covered with different masks using plasma gas is employed to form through-silicon vias (TSVs) with varying center-to-center spacing. SiO2 insulating layers are deposited on the sidewalls of these TSVs using chemical deposition. A Ti barrier layer is deposited on the surface of the SiO2 insulating layer using PVD magnetron sputtering. A Cu-filled metal layer is then prepared on the Ti barrier layer using electroplating, forming TSV structural units with varying center-to-center spacing. Chemical mechanical polishing is performed on the front and back sides of the silicon wafers to expose the Cu-filled metal layers at both ends of the TSVs, resulting in a TSV adapter board with the same aspect ratio and thickness but different center-to-center spacing of the TSV structural units.

[0011] Ultrasonic scanning microscopy was used to scan the TSV structural units in the XY plane of each TSV adapter board to verify that there were no pore defects inside the Cu-filled metal layer and at the interface of the silicon wafer / SiO2 insulating layer / Ti barrier layer / Cu-filled metal layer. Samples of the TSV adapter board were prepared and examined under a microscope in the XY plane to verify that the center point spacing of the TSV structural units was consistent with the design value. Samples of the XZ plane were prepared and examined under a microscope to verify that each TSV structural unit was cylindrical and that there were no pore defects inside the Cu-filled metal layer and at the interface of the silicon wafer / SiO2 insulating layer / Ti barrier layer / Cu-filled metal layer.

[0012] The structural analysis method for optimizing the heat dissipation performance of the TSV adapter board using the transient thermal resistance curve mentioned above includes, in which the test of the TSV adapter board breakdown voltage curve includes:

[0013] The applied voltage between the Cu-filled metal layers in two adjacent TSV structural units was increased, and a voltage-time curve was plotted using a voltage acquisition device. When the applied voltage suddenly dropped, the SiO2 insulating layer and silicon wafer between the Cu-filled metal layers were broken down by the high voltage, and the peak voltage of the curve was taken as the breakdown voltage of the TSV adapter plate. As the center-point spacing of the TSV adapter plate increased, the corresponding breakdown voltage increased sequentially, and the insulation performance of the TSV adapter plate was continuously enhanced. However, as the center-point spacing of the TSV adapter plate continued to increase, the rate of increase in breakdown voltage slowed down, and the insulation performance of the TSV adapter plate improved most significantly in the range of 100–200 μm.

[0014] The structural analysis method for optimizing the heat dissipation performance of TSV adapter boards based on transient thermal resistance curves, wherein the step of encapsulating diode chips on TSV adapter boards to obtain diode devices with different center point spacings of TSV structural units includes:

[0015] The diode chip is mounted and fixed on the surface of a TSV adapter board with different center point spacing of the structural units using tin-lead solder; the positive and negative leads are mounted and fixed on the surface of the TSV adapter board using high-temperature resistant insulating adhesive; the diode chip, the positive lead, and the negative lead are connected using bonding wire; the TSV adapter board, the diode chip, the bonding wire, the positive lead, and the negative lead are injection molded to form a plastic-encapsulated shell, resulting in a packaged diode device with different center point spacing of the TSV structural units using the TSV adapter board as the substrate.

[0016] The above-mentioned structural analysis method for optimizing the heat dissipation performance of TSV adapter boards using transient thermal resistance curves includes, in part, testing the differential structure function curve of diode devices using the transient thermal resistance method, which includes:

[0017] Determine the K coefficient, a temperature-sensitive parameter of the diode device;

[0018] Thermal grease was applied to the bottom of diode devices with different TSV structural unit center point spacings, using a TSV adapter plate as the substrate, and then fixed to the upper surface of a constant-temperature heat dissipation Cu block cold plate. A heating current was applied to the diode devices, and a voltage sensor was used to monitor the PN junction voltage drop curve. The PN junction voltage drop curve was converted into a transient cooling curve using the aforementioned K coefficient, and then mathematically transformed into a differential function curve. For the differential function curves of diode devices with different TSV structural unit center point spacings, the horizontal axis represents thermal... Resistance is represented on the vertical axis, which is the thermal capacity. The horizontal axis corresponding to the thermal resistance from the origin to the first main peak represents the thermal resistance of the diode chip. The horizontal axis corresponding to the thermal resistance from the first main peak to the second main peak represents the thermal resistance of the solder. The horizontal axis corresponding to the thermal resistance from the second main peak to the third main peak represents the thermal resistance of the TSV adapter board. The horizontal axis corresponding to the thermal resistance from the third main peak to the rightmost end of the differential function curve represents the sum of the thermal resistance of the thermal grease and the constant temperature heat dissipation Cu block cold plate. The horizontal axis corresponding to the thermal resistance from the origin to the rightmost end of the differential function curve represents the total thermal resistance of the diode device.

[0019] Evaluate the thermal resistance ratio of the TSV adapter plate relative to the total thermal resistance of the diode device.

[0020] The above-mentioned structural analysis method for optimizing the heat dissipation performance of the TSV adapter board using transient thermal resistance curves includes determining the temperature-sensitive parameter K coefficient of the diode device, which includes:

[0021] The diode devices with different center point spacings of the TSV structural unit based on the TSV adapter board were connected to the circuit respectively; only the test current was applied to the diode devices, and the change of PN junction voltage drop of the diode devices was monitored in real time by a voltage sensor; the diode devices were placed in an oil bath, and the oil temperature was adjusted to increase the PN junction temperature of the diode devices; the PN junction voltage drop-junction temperature curve of the diode devices was recorded in real time to obtain the K coefficient of the diode devices with different center point spacings of the TSV structural unit.

[0022] The structural analysis method for optimizing the heat dissipation performance of the TSV adapter board using the transient thermal resistance curve, wherein the thermal resistance ratio coefficient for evaluating the thermal resistance of the TSV adapter board relative to the total thermal resistance of the diode device includes:

[0023] If the thermal resistance ratio coefficient z ≥ 30%, the change in the center-point spacing of the TSV structural units within the TSV adapter plate has a significant impact on the total thermal resistance of the diode device; if the thermal resistance ratio coefficient u ≤ 30%, the change in the center-point spacing of the TSV structural units within the TSV adapter plate has a smaller impact on the total thermal resistance of the diode device.

[0024] The structural analysis method for optimizing the heat dissipation performance of TSV adapter boards using transient thermal resistance curves, wherein the relationship between the center-point spacing of the TSV structural units and the thermal resistance parameters includes:

[0025] The thermal resistance of the chip and the thermal resistance of the solder are the same for diode devices with different TSV structural unit center point spacings; the thermal resistance of the corresponding TSV adapter board is different. As the TSV structural unit center point spacing increases, the thermal resistance of the TSV adapter board increases. The increase in the thermal resistance of the TSV adapter board in the 300-400μm range is significantly greater than that in the 100-300μm range; the sum of the thermal resistances of the corresponding thermal grease and the constant temperature heat dissipation Cu block cold plate is equal; the total thermal resistance of the corresponding diode devices is different. As the TSV structural unit center point spacing increases, the total thermal resistance increases; for any two diode devices with different TSV structural unit center point spacings, the difference in total thermal resistance is equal to the difference in the thermal resistance of the corresponding TSV adapter board.

[0026] The above-mentioned structural analysis method for optimizing the heat dissipation performance of TSV adapter boards based on transient thermal resistance curves includes, in part, determining the optimal TSV structural unit center-point spacing range based on the TSV adapter board's breakdown voltage and thermal resistance curves, which includes:

[0027] The breakdown voltage-spacing curve of the TSV adapter board and the thermal resistance-spacing curve of the TSV adapter board were superimposed. As the spacing between the center points of the structural units of the TSV adapter board increases, the breakdown voltage increases sequentially, and the insulation performance of the TSV adapter board is continuously enhanced. The enhancement effect of the insulation performance of the TSV adapter board is most obvious in the range of 100-200μm.

[0028] As the center-point spacing of the TSV adapter board structural units increases, the thermal resistance of the TSV adapter board increases sequentially. Moreover, the increase in thermal resistance of the TSV adapter board in the range of 300 to 400 μm is significantly greater than that in the range of 100 to 300 μm, and the heat dissipation performance of the TSV adapter board deteriorates continuously.

[0029] Within a spacing range of 100–200 μm, based on the minimum breakdown voltage j min Based on the relationship between the breakdown voltage of the TSV adapter board and the center-point spacing, the minimum center-point spacing b of the TSV structural unit is calculated. min ;

[0030] Within a spacing range of 100–300 μm, based on the maximum thermal resistance T of the TSV adapter plate max Based on the relationship between the thermal resistance of the TSV adapter plate and the center-point spacing, the maximum center-point spacing b of the TSV structural unit is calculated. max ;

[0031] Based on the minimum TSV structural unit center point spacing b min and the maximum TSV structural unit center point spacing b max Determine the safe spacing range of the center point of the TSV structural unit.

[0032] Compared with the prior art, the beneficial effects of the present invention include:

[0033] 1. The simulated thermal resistance parameters of the TSV adapter board obtained by simulation methods differ significantly from the actual thermal resistance parameters. This invention constructs a one-dimensional heat dissipation path and uses the transient thermal resistance method to isolate the heat dissipation performance of the TSV adapter board from the heat dissipation performance of the semiconductor device. This determines the degree of change of the thermal resistance of the TSV adapter board relative to the overall thermal resistance of the device. The obtained thermal resistance parameters of the TSV adapter board are more accurate than the simulation parameters, and the simulation results can be further corrected.

[0034] 2. This invention quantitatively calculates the impact of through-silicon via (TSV) density within the TSV adapter board on the thermal resistance of the TSV adapter board, and provides the optimal heat dissipation density range for the TSV structural units within the TSV adapter board. This ensures that the TSV structural units can effectively conduct heat from the chip to the package shell, while also ensuring sufficient breakdown strength between the TSV structural units and the silicon wafer, avoiding reliability issues due to poor insulation. This solves the problem that traditional methods cannot experimentally quantify the impact of TSV density within the TSV adapter board on the heat dissipation and insulation performance of semiconductor devices.

[0035] 3. The heat-dissipating TSV adapter board designed in this invention only serves a heat dissipation function and does not include a conductive function. The interconnection and heating of the chip are mainly achieved through bonding wires, thereby simplifying the complex TSV interconnection process and reducing a series of reliability issues such as internal stress, filling defects, and interconnection defects generated when the TSV adapter board is interconnected with the chip and substrate. This avoids the impact of these defects on the heat dissipation performance of the TSV adapter board. At the same time, the heat dissipation state of the TSV adapter board in this invention is very close to that of the conductive TSV adapter board, and the obtained thermal resistance value of the TSV adapter board is closer to the actual value.

[0036] 4. This invention uses the thermal resistance of the TSV adapter board to characterize the heat dissipation performance of the TSV adapter board, instead of using the overall thermal resistance of the device to characterize the heat dissipation performance of the TSV adapter board. This can effectively avoid the influence of other packaging structures such as chip thermal resistance and solder thermal resistance on the heat dissipation performance of the TSV adapter board. The obtained thermal resistance of the TSV adapter board is more representative of the heat dissipation performance of the TSV adapter board than the overall thermal resistance of the device. Attached Figure Description

[0037] Figure 1 This is a flowchart illustrating the structural analysis method for optimizing the heat dissipation performance of the TSV adapter plate using transient thermal resistance curves in a preferred embodiment of the present invention.

[0038] Figure 2 This is a schematic diagram of dry etching of a silicon wafer covering a mask in a preferred embodiment of the present invention;

[0039] Figure 3This is a schematic diagram of a preferred embodiment of the present invention, in which a SiO2 insulating layer, a Ti barrier layer and a Cu filled metal layer are sequentially prepared in a through-silicon via (TSV) to form a TSV structural unit.

[0040] Figure 4 This is a schematic diagram of the TSV adapter board after grinding in a preferred embodiment of the present invention;

[0041] Figure 5 This is a schematic diagram of a TSV adapter plate with different center point spacing of TSV structural units in a preferred embodiment of the present invention;

[0042] Figure 6 This is a schematic diagram of the verification of the absence of pore defects in the XY plane of the TSV adapter plate using an ultrasonic scanning microscope in a preferred embodiment of the present invention.

[0043] Figure 7 This is a schematic diagram illustrating the spacing between the center points of each TSV structural unit of the TSV adapter plate during XY plane sample preparation and microscopic examination in a preferred embodiment of the present invention.

[0044] Figure 8 This is a schematic diagram illustrating the verification of the absence of pore defects in the TSV adapter plate by microscopic examination of XZ plane sample preparation in a preferred embodiment of the present invention.

[0045] Figure 9 This is a schematic diagram of detecting the breakdown voltage of the TSV adapter board in a preferred embodiment of the present invention;

[0046] Figure 10 This is a superimposed diagram of breakdown voltage curves of TSV adapter plates with different center point spacings of TSV structural units in a preferred embodiment of the present invention.

[0047] Figure 11 This is a schematic diagram of a preferred embodiment of the present invention showing the mounting and fixing of a diode chip, electrode leads, and bonding connections on the upper surface of a TSV adapter board.

[0048] Figure 12 This is a schematic diagram of a packaged diode device using a TSV adapter board as a substrate in a preferred embodiment of the present invention.

[0049] Figure 13 This is a circuit diagram of transient thermal resistance testing for diode devices using a TSV adapter board as the substrate, as a preferred embodiment of the present invention.

[0050] Figure 14 This is a cross-sectional view of the one-dimensional heat conduction path of a diode device with a TSV adapter plate as the substrate in a preferred embodiment of the present invention.

[0051] Figure 15 This is the differential function curve p1 corresponding to a diode device with a TSV structure unit center point spacing of 100μm in a preferred embodiment of the present invention;

[0052] Figure 16 This is a superimposed graph of differential function curves corresponding to diode devices with different center point spacings in the TSV structure unit in a preferred embodiment of the present invention.

[0053] Figure 17 This is a schematic diagram showing the safe spacing range of the center point of the TSV structure unit of the diode device in a preferred embodiment of the present invention. Detailed Implementation

[0054] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0055] This invention solves the problem that existing technologies cannot experimentally quantify the impact of through-silicon via (TSV) density within a TSV adapter plate on the heat dissipation and insulation performance of diode devices. The structural analysis method for optimizing the heat dissipation performance of a TSV adapter plate using transient thermal resistance curves includes: preparing TSV adapter plates with different center-point spacings for TSV structural units; testing the breakdown voltage curve of the TSV adapter plate; encapsulating diode chips on the TSV adapter plate to obtain diode devices with different center-point spacings for TSV structural units; using the transient thermal resistance method to test the differential structure function curve of the diode devices to obtain the relationship between the center-point spacing of the TSV structural units and the thermal resistance parameter; and determining the optimal range of center-point spacing for the TSV structural units based on the breakdown voltage curve and thermal resistance curve of the TSV adapter plate.

[0056] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments.

[0057] Figure 1 This is a flowchart illustrating the structural analysis method for optimizing the heat dissipation performance of the TSV adapter board using transient thermal resistance curves, as described in a preferred embodiment of the present invention.

[0058] S1, Prepare TSV adapter plates with different center point spacings of TSV structural units;

[0059] S11, such as Figure 2 A mask 111 of a specific shape is placed on a silicon wafer 112. The mask 111 contains circular holes 113, each with a diameter of 20 μm and a center-to-center spacing of 100 μm, arranged in an array. The silicon wafer 112 covering the mask 111 is dry etched using plasma gas 114. The plasma gas 114 reacts with the circular hole areas in the silicon wafer 112 that are not covered by the mask to form through-silicon vias 115, each with a diameter of 20 μm, a depth of 200 μm, an aspect ratio of 10:1, and a center-to-center spacing of 100 μm, arranged in an array.

[0060] S12, as Figure 3A SiO2 insulating layer 117, a Ti barrier layer 118, and a Cu-filled metal layer 119 are sequentially prepared within a through-silicon via 115 to form a TSV structural unit 120. First, a SiO2 insulating layer 117 with a thickness of 50-100 nm is deposited on the sidewall of the through-silicon via 115 using chemical deposition. Then, a Ti barrier layer 118 with a thickness of 50-100 nm is deposited on the surface of the SiO2 insulating layer 117 using PVD magnetron sputtering. Finally, a Cu-filled metal layer 119 is prepared on the surface of the Ti barrier layer 118 on the sidewall of the through-silicon via 115 using electroplating until the entire through-silicon via 115 is completely filled, forming a TSV structural unit 120. The SiO2 insulating layer 117 is used to prevent leakage current in each TSV structural unit 120 and to prevent mutual interference between the TSV structural units 120. The Ti barrier layer 118 is used to improve the bonding strength between the SiO2 insulating layer 117 and the Cu-filled metal layer 119 and to prevent the Cu-filled metal layer 119 from diffusing into the SiO2 insulating layer 117 and the silicon wafer 112.

[0061] S13, as Figure 4 The mask 111 is removed, and the upper surface of the silicon wafer 112 containing the TSV structural unit 120 is polished using a chemical mechanical polishing process to expose the Cu-filled metal layer 119 on the upper surface of the TSV structural unit 120. Then, the lower surface of the silicon wafer 112 containing the TSV structural unit 120 is polished to expose the Cu-filled metal layer 119 on the lower surface of the TSV structural unit 120, and the thickness of the silicon wafer 112 is polished to 200μm to obtain a TSV adapter plate 122 with a center-to-center spacing of 100μm for the TSV structural unit 120.

[0062] S14, as Figure 5 By designing mask plates 111 with different patterns and changing the center point spacing of the inner circular holes 113 of the mask plate 111, steps S11 to S13 are repeated to obtain TSV adapter plates 122 with the same aspect ratio and thickness but different center point spacing of TSV structural units 120; the center point spacing of TSV structural units 120 are 100μm, 200μm, 300μm and 400μm respectively;

[0063] S2, Ultrasonic scanning microscopy verifies that the TSV structural unit has no porosity defects;

[0064] like Figure 6An ultrasonic scanning microscope 124 was used to scan the TSV structural units 120 in the X-Y plane of each TSV adapter board 122 to verify that there are no pore defects inside the Cu-filled metal layer 119 and at the interface between the silicon wafer 112 / SiO2 insulating layer 117 / Ti barrier layer 118 / Cu-filled metal layer 119. Pore defects will affect the heat dissipation of the TSV adapter board 122. If there are voids inside the TSV adapter board 122, the thermal resistance of the TSV adapter board 122 will be significantly increased and the heat dissipation performance will be significantly reduced, which may interfere with the thermal resistance characterization results of TSV adapter boards 122 with different center point spacing of TSV structural units 120.

[0065] S3, sample preparation and microscopic examination to verify the center point spacing of the TSV structural unit, verifying that the TSV structural unit is cylindrical and free of porosity defects;

[0066] like Figure 7 The XY plane of the TSV adapter plate 122 was sampled and examined under a microscope. The center point spacing bt1, bt2, bt3 and bt4 of each TSV structural unit 120 was measured using a scanning electron microscope to verify whether it was consistent with the design values ​​of 100μm, 200μm, 300μm and 400μm.

[0067] like Figure 8 The XZ plane of the TSV adapter board 122 was prepared and examined under a microscope. Scanning electron microscopy was used to verify that each TSV structural unit 120 is cylindrical and not conical. It was also verified that there are no pore defects inside the Cu-filled metal layer 119 and at the interface of silicon wafer 112 / SiO2 insulating layer 117 / Ti barrier layer 118 / Cu-filled metal layer 119.

[0068] S4. Apply high voltage to each TSV adapter board to determine the TSV adapter board breakdown voltage-TSV structural unit center point spacing curve.

[0069] S41, as Figure 9The TSV adapter board 122, adjustable DC high-voltage power supply 141, and voltage acquisition device 142 are sequentially connected to the circuit. The positive terminal of the adjustable DC high-voltage power supply 141 is connected to the upper surface of the Cu-filled metal layer 119 inside the TSV structural unit 120 in a point-contact manner, and the negative terminal is connected to the upper surface of the Cu-filled metal layer 119 inside the adjacent TSV structural unit 120 in a point-contact manner. The distance between two adjacent TSV structural units is the distance between the center points of the TSV structural units. The positive terminal of the voltage acquisition device 142 is also connected to the upper surface of the Cu-filled metal layer 119 inside the TSV structural unit 120 in a point-contact manner. The negative electrode is connected to the upper surface of the Cu-filled metal layer 119 in the adjacent TSV structural unit 120 in a point contact manner; the high voltage will pass through the Cu-filled metal layer 119 / Ti barrier layer 118 / SiO2 insulating layer 117 / silicon wafer 112 / SiO2 insulating layer 117 / Ti barrier layer 118 / Cu-filled metal layer 119 in sequence; when the center point spacing of the TSV structural unit changes, the applied voltage between the Cu-filled metal layers 119 in the two adjacent TSV structural units 120 will also change, and the voltage acquisition device 142 will record the applied voltage in real time and save it to the PC computer;

[0070] S42, continuously increase the loading voltage applied between the Cu-filled metal layers 119 in two adjacent TSV structural units 120, and plot the loading voltage-loading time curve using a voltage acquisition device; when the loading voltage drops sharply, it indicates that the SiO2 insulating layer 117 and silicon wafer 112 between the Cu-filled metal layers 119 are broken down by high voltage, and the peak voltage of the loading voltage-loading time curve is taken as the breakdown voltage of the TSV adapter plate 122; record the loading voltage-loading time curves for TSV adapter plates 122 with different center point spacings of TSV structural units, and superimpose the curves; Figure 10 This is a superimposed diagram of breakdown voltage curves of TSV adapter plates with different center point spacings in a preferred embodiment of the present invention; as shown below. Figure 10Let the load voltage-load time curves of TSV adapter plates with center point spacing of 100μm, 200μm, 300μm and 400μm be q1, q2, q3 and q4 respectively. When the center point spacing of the TSV structural units increases from 100μm, 200μm, 300μm to 400μm, the breakdown voltage of the corresponding TSV adapter plate increases from jc1, jc2, jc3 to jc4, and the insulation performance of the TSV adapter plate is continuously enhanced. However, as the center point spacing of the TSV adapter plate continues to increase, the increase in breakdown voltage slows down. The increase is the largest from jc1 to jc2, indicating that the insulation performance of the TSV adapter plate is most significantly improved in the range of 100 to 200μm, while the insulation performance of the TSV adapter plate is not significantly improved in the range of 200 to 400μm.

[0071] S5, the diode chip is packaged on the TSV adapter board to obtain diode devices with different center point spacing of TSV structural units;

[0072] S51, such as Figure 11 The diode chip 151 is mounted and fixed on the upper surface of the TSV adapter board 122 using tin-lead solder 150; the positive terminal 153 and the negative terminal 154 are mounted and fixed on the upper surface of the TSV adapter board 122 using high-temperature resistant insulating adhesive 152; and the diode chip 151, the positive terminal 153 and the negative terminal 154 are connected using bonding wire 155.

[0073] S52, such as Figure 12 The TSV adapter plate 122, diode chip 151, bonding wire 155, lead-out positive terminal 153 and lead-out negative terminal 154 are injection molded to form a plastic encapsulated shell 156, thereby obtaining a packaged diode device with the TSV adapter plate 122 as the substrate.

[0074] S53, repeat steps S51 and S52 on TSV adapter boards 122 with different center point spacing of TSV structural units respectively, and you can obtain packaged diode devices with different center point spacing of TSV structural units based on TSV adapter board 122.

[0075] S6, Determine the temperature sensitivity parameter K coefficient of the diode device;

[0076] S61, such as Figure 13A circuit connection was made for a diode device based on a TSV adapter board. The positive terminal 153 of the diode device was connected to the positive terminals of the VF voltage sensor 160, the IM test current 161, and the IH heating current 162, respectively. The negative terminal 154 of the diode device was connected to the negative terminals of the VF voltage sensor 160, the IM test current 161, and the IH heating current 162, respectively. Since the actual directions of the VF voltage sensor 160, the IM test current 161, and the IH heating current 162 are the same, all three are displayed as positive (+). A T3ster device was used to apply only 5mA of IM test current 161 to the diode device based on the TSV adapter board, without applying IH heating current 162. The VF voltage sensor 160 was used to monitor the change in PN junction voltage drop of the diode device based on the TSV adapter board in real time.

[0077] S62, the diode device with TSV adapter board as substrate is placed in oil tank 163, the temperature of oil 164 is equal to the PN junction temperature of the diode device; the temperature of oil 164 is adjusted to gradually increase the PN junction temperature of the diode device from 25℃ to 140℃, the heating rate is 5℃ / minute; the PN junction voltage drop-junction temperature curve of the diode device is recorded in real time to obtain the K coefficient of the diode device.

[0078] S63, Perform steps S61 and S62 respectively on diode devices with different center point spacing of TSV structural units based on TSV adapter plate 122 to obtain the corresponding K coefficients;

[0079] S7. The transient thermal resistance method was used to test the differential structure function curves of diode devices with different center point spacings of TSV structural units, and the relationship between the center point spacing of structural units and thermal resistance parameters was obtained.

[0080] S71, such as Figure 14 After applying thermal grease 171 to the bottom of the diode device with the TSV adapter plate as the substrate, it is then fixed to the upper surface of the constant temperature heat dissipation Cu block cold plate 172, and the temperature of the Cu block cold plate 172 is maintained at 25°C. During the transient thermal resistance test, the diode device with the TSV adapter plate as the substrate satisfies a one-dimensional heat dissipation path. The heat generated by the diode chip 151 is mainly conducted outward through the heat dissipation path of tin-lead solder 150-TSV adapter plate 122-thermal grease 171-constant temperature heat dissipation Cu block cold plate 172. The TSV adapter plate 122 includes a silicon wafer 112 and a series of TSV structural units 120 arranged in an array. When the center point spacing of the TSV structural units is different, the thermal resistance of the TSV adapter plate 122 is different, the heat transfer efficiency of the TSV adapter plate 122 will change, and the curve obtained by the transient thermal resistance test will change.

[0081] S72, using T3ster equipment, a 5A IH heating current 162 is applied to the diode device with TSV adapter board as the substrate. After the junction temperature of the diode device reaches thermal steady state, the IH heating current 162 is quickly switched to IM test current 161. The PN junction voltage drop curve of the diode device is monitored by VF voltage sensor 160 until the PN junction voltage drop of the diode device reaches a stable value.

[0082] S73, using the K coefficient from step S6, the PN junction voltage drop curve is transformed into a transient cooling curve;

[0083] S74 transforms the transient cooling curve into a differential function curve through mathematical transformation;

[0084] S75, Steps S71 to S74 are performed on diode devices with different center point spacings of TSV structural unit 120 with TSV adapter plate 122 as substrate to obtain the differential function curves of each diode device; let the differential function curves corresponding to the diode devices with center point spacings of 100μm, 200μm, 300μm and 400μm of TSV structural unit 120 be p1, p2, p3 and p4 respectively.

[0085] Figure 15 In a preferred embodiment of the present invention, the differential function curve p1 corresponds to a diode device with a TSV structure unit center-to-center spacing of 100 μm. In the differential function curve p1, the horizontal axis represents the thermal resistance value, and the vertical axis represents the thermal capacitance value. The horizontal axis thermal resistance value corresponding to the first main peak represents the thermal resistance d1 of the diode device chip. The horizontal axis thermal resistance value corresponding to the second main peak represents the thermal resistance s1 of the tin-lead solder. The horizontal axis thermal resistance value corresponding to the third main peak represents the thermal resistance t1 of the TSV adapter board with a TSV structure unit center-to-center spacing of 100 μm. The horizontal axis thermal resistance value corresponding to the rightmost end of the differential function curve from the third main peak represents the sum of the thermal resistance n1 of the thermally conductive silicone grease and the constant temperature heat dissipation Cu block cold plate. The horizontal axis thermal resistance value corresponding to the rightmost end of the differential function curve from the origin represents the total thermal resistance h1 of the diode device (h1 = d1 + s1 + t1 + n1).

[0086] The TSV structure unit center point spacings are b2, b3, and b4, respectively. The corresponding chip thermal resistances of the diode devices are d2, d3, and d4, respectively; the corresponding tin-lead solder thermal resistances are s2, s3, and s4, respectively; the corresponding TSV adapter board thermal resistances are t2, t3, and t4, respectively; the sum of the corresponding thermal grease and constant temperature heat dissipation Cu block cold plate thermal resistances are n2, n3, and n4, respectively; and the corresponding total thermal resistances of the diode devices are h2, h3, and h4, respectively.

[0087] The thermal resistance ratio coefficient z, relative to the total thermal resistance of the TSV adapter plate, is evaluated as follows: z1 = t1 / h1, z2 = t2 / h2, z3 = t3 / h3, z4 = t4 / h4. If the thermal resistance ratio coefficient z ≥ 30%, it indicates that the change in the center-point spacing of the TSV structural units within the TSV adapter plate has a significant impact on the total thermal resistance of the diode device, and special attention should be paid to the change in the center-point spacing of the TSV structural units within the TSV adapter plate. If the thermal resistance ratio coefficient u ≤ 30%, it indicates that the change in the center-point spacing of the TSV structural units within the TSV adapter plate has a relatively small impact on the total thermal resistance of the diode device.

[0088] Figure 16 This is a superimposed graph of the differential function curves corresponding to diode devices with different center point spacings in the TSV structure unit of the present invention in a preferred embodiment of the present invention; for example... Figure 16 In the superimposed differential function curves, the chip thermal resistances of diode devices with different TSV structural unit center point spacings are the same, i.e., d1=d2=d3=d4, and the differential function curve segments from the origin to the first main peak overlap. The corresponding tin-lead solder thermal resistances are also the same, i.e., s1=s2=s3=s4, and the differential function curve segments from the first main peak to the second main peak also overlap. The differential function curve segments corresponding to the diode chip and the tin-lead solder indicate that the chip and tin-lead solder of diode devices with different TSV structural unit center point spacings do not affect the total thermal resistance.

[0089] like Figure 16 The thermal resistance of the TSV adapter plate varies for diode devices with different TSV structural unit center point spacings. As the TSV structural unit center point spacing increases sequentially from 100μm, 200μm, 300μm to 400μm, the thermal resistance of the TSV adapter plate increases sequentially from t1, t2, t3 to t4. The differential function curve segment from the second main peak to the third main peak shifts to the right, and the amount of shift is related to the TSV structural unit center point spacing; the larger the spacing, the greater the rightward shift. As the TSV structural unit center point spacing increases, the increase in TSV adapter plate thermal resistance also increases. The increase in TSV adapter plate thermal resistance in the 300–400μm range is significantly greater than that in the 100–300μm range.

[0090] like Figure 16 The sum of the thermal resistance of the thermal grease and the constant temperature heat dissipation Cu block cold plate corresponding to the diode devices with different TSV structural unit center point spacing is the same, that is, n1=n2=n3=n4. Although the corresponding differential function curve segments do not overlap, the basic trend is consistent. This curve segment shows that the thermal grease and the constant temperature heat dissipation Cu block cold plate corresponding to the diode devices with different TSV structural unit center point spacing will not affect the total thermal resistance.

[0091] like Figure 16 The total thermal resistance of diode devices with different TSV structural unit center point spacings is different. As the TSV structural unit center point spacing increases from 100μm, 200μm, 300μm to 400μm, the total thermal resistance of the diode device from the origin to the rightmost end of the differential function curve increases from h1, h2, h3 to h4. For any two diode devices with different TSV structural unit center point spacings, the difference in the total thermal resistance of the diode device is equal to the difference in the thermal resistance of the corresponding TSV adapter plate, i.e., h4-h1=t4-t1, h3-h1=t3-t1, h2-h1=t2-t1. This indicates that the difference in the total thermal resistance of the diode device is mainly caused by the difference in the TSV structural unit center point spacing within the TSV adapter plate, excluding the influence of other packaging structures on the total thermal resistance of the diode device.

[0092] S8. Determine the optimal TSV structural unit center point spacing range based on the TSV adapter board breakdown voltage curve and the TSV adapter board thermal resistance curve.

[0093] Figure 17 This is a schematic diagram of the safe spacing range of the center point of the TSV structure unit of the diode device in a preferred embodiment of the present invention, wherein 183 is the safe spacing range of the center point of the TSV structure unit;

[0094] like Figure 17 After excluding the influence of other packaging structures on the total thermal resistance, the breakdown voltage-center-spacing dashed line 181 and the thermal resistance-center-spacing solid line 182 of the TSV adapter board are superimposed. From the breakdown voltage-center-spacing dashed line 181, it can be seen that as the center-spacing of the TSV adapter board increases from 100μm, 200μm, 300μm to 400μm, the corresponding breakdown voltage increases sequentially from jc1, jc2, jc3 to jc4. The insulation performance of the TSV adapter board continuously improves, and the improvement in insulation performance is most pronounced in the 100–200μm range. Clearly, as shown by the solid line 182 representing the thermal resistance of the TSV adapter board versus the center-point spacing, when the center-point spacing of the TSV adapter board increases from 100μm, 200μm, 300μm to 400μm, the corresponding thermal resistance of the TSV adapter board increases sequentially from t1, t2, t3 to t4. Furthermore, the increase in thermal resistance within the 300–400μm range is significantly greater than that within the 100–300μm range, indicating a continuous deterioration in the heat dissipation performance of the TSV adapter board. Therefore, it is essential to determine the safe spacing range for the TSV adapter board to balance its insulation and heat dissipation performance.

[0095] like Figure 17 Within a spacing range of 100–200 μm, based on the minimum breakdown voltage j minBased on the relationship between the breakdown voltage of the TSV adapter board and the center-point spacing (TSV adapter board breakdown voltage - center-point spacing dashed line 181), the minimum TSV structural unit center-point spacing b is calculated. min ;

[0096] like Figure 17 Within the spacing range of 100–300 μm, based on the maximum thermal resistance T of the micro-arc oxidation film... max Based on the relationship between the thermal resistance of the TSV adapter board and the center-point spacing (TSV adapter board thermal resistance - center-point spacing solid line 182), the maximum center-point spacing b of the TSV structural unit is calculated. max ;

[0097] like Figure 17 Based on the minimum TSV structural unit center point spacing b min and the maximum TSV structural unit center point spacing b max The safe spacing range of the center point of the TSV structural unit is determined to be 183.

[0098] Obviously, those skilled in the art can make various modifications and variations to the invention without departing from the spirit and scope of the invention. Therefore, if these modifications and variations fall within the scope of the claims of the invention and their equivalents, the invention is also intended to include these modifications and variations.

Claims

1. A structural analysis method for optimizing the heat dissipation performance of a TSV adapter board using transient thermal resistance curves, characterized in that... Including the following steps: Step S1: Prepare TSV adapter plates with different center point spacings for TSV structural units; Step S2: Test the breakdown voltage curve of the TSV adapter board; In step S2, the method for testing the breakdown voltage curve of the TSV adapter board includes: Increase the loading voltage applied between the Cu-filled metal layers in two adjacent TSV structural units, and plot the loading voltage-loading time curve using a voltage acquisition device; When the applied voltage drops sharply, the SiO2 insulating layer and silicon wafer between the Cu-filled metal layers are broken down by high voltage, and the peak voltage of the curve is taken as the breakdown voltage of the TSV adapter plate. Step S3: Package the diode chip onto the TSV adapter board to obtain diode devices with different center point spacings of TSV structural units; Step S4: Use the transient thermal resistance method to test the differential structure function curve of the diode device and obtain the relationship between the center point spacing of the TSV structure unit and the thermal resistance parameter; The method for testing the differential structure function curve of a diode device using the transient thermal resistance method in step S4 includes: Determine the K coefficient, a temperature-sensitive parameter of the diode device; After applying thermal grease to the bottom of the diode devices with different TSV structural unit center point spacings using the TSV adapter plate as the substrate, they are then fixed to the upper surface of the constant temperature heat dissipation Cu block cold plate. A heating current is applied to the diode device, and a voltage sensor is used to monitor the PN junction voltage drop curve of the diode device; The PN junction voltage drop curve is transformed into a transient cooling curve using the K coefficient, and then the transient cooling curve is transformed into a differential function curve through mathematical transformation. For the differential function curves of diode devices with different TSV structural unit center point spacings, the horizontal axis represents thermal resistance and the vertical axis represents thermal capacitance. The horizontal axis thermal resistance value corresponding to the first main peak from the origin represents the thermal resistance of the diode device chip; the horizontal axis thermal resistance value corresponding to the second main peak represents the thermal resistance of the solder; the horizontal axis thermal resistance value corresponding to the third main peak represents the thermal resistance of the TSV adapter board; the horizontal axis thermal resistance value corresponding to the rightmost end of the differential function curve from the third main peak represents the sum of the thermal resistance of the thermal grease and the constant temperature heat dissipation Cu block cold plate; the horizontal axis thermal resistance value corresponding to the rightmost end of the differential function curve from the origin represents the total thermal resistance of the diode device. Evaluate the thermal resistance ratio of the TSV adapter plate relative to the total thermal resistance of the diode device. Step S5: Determine the optimal TSV structural unit center point spacing range based on the TSV adapter board breakdown voltage curve and thermal resistance curve.

2. The structural analysis method for optimizing the heat dissipation performance of TSV adapter boards using transient thermal resistance curves as described in claim 1, characterized in that, In step S1, the method for preparing TSV adapter plates with different center point spacings of TSV structural units includes: Plasma gas is used to dry etch silicon wafers covered with different masks to form silicon vias with different center point spacings. SiO2 insulating layers are deposited on the sidewalls of silicon vias with different center point spacings in the circular holes; A Ti barrier layer is deposited on the surface of the SiO2 insulating layer; A Cu-filled metal layer was prepared on the surface of the Ti barrier layer to form TSV structural units with different center point spacings; Chemical mechanical polishing is performed on the front and back sides of the silicon wafer to expose the Cu-filled metal layer at both ends of the through-silicon via (TSV), resulting in TSV adapter boards with the same aspect ratio and thickness but different center point spacing of the TSV structural units.

3. The structural analysis method for optimizing the heat dissipation performance of TSV adapter boards using transient thermal resistance curves as described in claim 2, characterized in that, Step S1 further includes inspecting the TSV adapter plates with different center point spacings of the prepared TSV structural units. The inspection methods include: The TSV structural units in the XY plane of each TSV adapter board were scanned to verify that there were no pore defects inside the Cu-filled metal layer, the silicon wafer, the SiO2 insulating layer, the Ti barrier layer, and the interface of the Cu-filled metal layer. The XY plane of the TSV adapter plate was sampled and examined under a microscope to verify that the center point spacing of the TSV structural units was consistent with the design value. Samples were prepared and examined under a microscope in the XZ plane to verify that each TSV structural unit is cylindrical and that there are no pore defects inside the Cu-filled metal layer, at the interface of the silicon wafer, the SiO2 insulating layer, the Ti barrier layer, and the Cu-filled metal layer.

4. The structural analysis method for optimizing the heat dissipation performance of a TSV adapter board using transient thermal resistance curves as described in claim 1, characterized in that, The method for encapsulating diode chips on a TSV adapter board in step S3 to obtain diode devices with different center point spacings of TSV structural units includes: The diode chip is mounted and fixed on the surface of the TSV adapter board with different center point spacing of the structural unit using tin-lead solder. High-temperature resistant insulating adhesive is used to install and fix the positive and negative leads on the surface of the TSV adapter board; The diode chip, positive terminal, and negative terminal are connected using bonding wires. The TSV adapter board, diode chip, bonding wire, positive lead and negative lead are injection molded to form a plastic encapsulated shell, resulting in a packaged diode device with different center point spacing of TSV structural units based on the TSV adapter board.

5. The structural analysis method for optimizing the heat dissipation performance of a TSV adapter board using transient thermal resistance curves as described in claim 1, characterized in that, The method for determining the temperature-sensitive parameter K coefficient of a diode device includes: The diode devices with different center point spacings of the TSV structural unit based on the TSV adapter board were connected to the circuit respectively; only the test current was applied to the diode devices, and the change of PN junction voltage drop of the diode devices was monitored in real time by a voltage sensor; the diode devices were placed in an oil bath, and the oil temperature was adjusted to increase the PN junction temperature of the diode devices; the PN junction voltage drop-junction temperature curve of the diode devices was recorded in real time to obtain the K coefficient of the diode devices with different center point spacings of the TSV structural unit.

6. The structural analysis method for optimizing the heat dissipation performance of a TSV adapter board using transient thermal resistance curves as described in claim 1, characterized in that, The method for determining the relationship between the center point spacing of the TSV structural unit and the thermal resistance parameter in step S4 includes: The chip thermal resistance and tin-lead solder thermal resistance are the same for diode devices with different TSV structure unit center point spacing. The thermal resistance of the corresponding TSV adapter plate is different. As the center point spacing of the TSV structural unit increases, the thermal resistance of the TSV adapter plate increases. The increase in thermal resistance of the TSV adapter plate in the range of 300~400μm is greater than that in the range of 100~300μm. The sum of the thermal resistances of the corresponding thermal grease and the constant-temperature heat dissipation Cu block cold plate is equal; The total thermal resistance of the corresponding diode devices is different. As the spacing between the center points of the TSV structure unit increases, the total thermal resistance increases. For any two TSV structure units with different center point spacing, the difference in total thermal resistance is equal to the difference in thermal resistance of the corresponding TSV adapter plates.

7. The structural analysis method for optimizing the heat dissipation performance of a TSV adapter board using transient thermal resistance curves as described in claim 6, characterized in that, The method for determining the optimal TSV structural unit center point spacing range in step S5 based on the TSV adapter board breakdown voltage curve and thermal resistance curve includes: The breakdown voltage-spacing curve of the TSV adapter board and the thermal resistance-spacing curve of the TSV adapter board are superimposed. Within a spacing range of 100~200μm, based on the minimum breakdown voltage j min Based on the relationship between the breakdown voltage of the TSV adapter board and the center-point spacing, the minimum center-point spacing b of the TSV structural unit is calculated. min ; Within a pitch range of 100~300μm, based on the maximum thermal resistance T of the TSV adapter plate max Based on the relationship between the thermal resistance of the TSV adapter plate and the center-point spacing, the maximum center-point spacing b of the TSV structural unit is calculated. max ; Based on the minimum TSV structural unit center point spacing b min and the maximum TSV structural unit center point spacing b max Determine the safe spacing range of the center point of the TSV structural unit.

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