Stress distribution detection methods, systems, and equipment for manufacturing packaging substrates

Abstract

This disclosure provides a stress distribution detection method, system, and manufacturing equipment for a packaging substrate. The stress distribution detection method includes: providing a packaging substrate, the packaging substrate including a first region and a second region, the first region penetrating the packaging substrate along a direction perpendicular to the packaging substrate; preparing a stress-sensitive material layer on the surface of the packaging substrate, the stress-sensitive material layer at least covering the first region; the optical properties of the stress-sensitive material layer changing with the mechanical stress applied to the stress-sensitive material layer; acquiring the optical response signal of the stress-sensitive material layer under the action of a stress field in the first region; and determining stress distribution information on the packaging substrate based on the optical response signal. This converts the invisible residual stress information inside the packaging substrate into an optical signal that can be detected by an optical system, thereby achieving non-contact, visualization, and localization of the residual stress field in the first region.

Description

Technical Field

[0001] This disclosure relates to the field of semiconductor technology, specifically to stress distribution detection methods, systems, and equipment for manufacturing packaging substrates. Background Technology

[0002] In the fabrication of through-glass vias (TGVs), the typical process involves first using laser-induced modification of the glass substrate material to create a modified region, followed by wet etching to remove the modified region and obtain the TGV. If stress concentration exists in the modified region, it can lead to uneven etching rates during subsequent wet etching, resulting in poor TGV morphology, rough hole walls, and increased susceptibility to crack propagation, leading to glass breakage and reduced structural strength and subsequent packaging reliability. Stress concentration on the TGV sidewalls can cause microcrack propagation during subsequent processes and service life, further reducing structural strength and reliability. When metal is filled into the TGV, abnormal morphology and poor interface bonding can occur, leading to delamination and cracking under high-temperature cycling, ultimately affecting packaging stability and device lifespan. Summary of the Invention

[0003] In view of this, embodiments of the present disclosure provide a stress distribution detection method, a system, and a manufacturing apparatus for a packaging substrate.

[0004] The first aspect of this disclosure provides a method for detecting stress distribution, including:

[0005] A packaging substrate is provided, the packaging substrate including a first region and a second region, the stress in at least a portion of the first region being greater than the stress in the second region, and the first region penetrating the packaging substrate in a direction perpendicular to the packaging substrate;

[0006] A stress-sensitive material layer is prepared on the surface of the encapsulation substrate, the stress-sensitive material layer at least covering a first region; the optical properties of the stress-sensitive material layer change with the mechanical stress applied to the stress-sensitive material layer;

[0007] Obtain the optical response signal of the stress-sensitive material layer under the stress field in the first region;

[0008] Based on the optical response signal, the stress distribution information on the packaging substrate is determined.

[0009] In one embodiment, the stress-sensitive material layer comprises a mechanoluminescent material.

[0010] Optionally, when the mechanical stress in the first region exceeds a first threshold, the stress-sensitive material layer at the corresponding location generates a fluorescent group.

[0011] Optionally, the first threshold is less than or equal to 150 MPa.

[0012] Optionally, the metronic fluorescent material comprises at least one of spiropyran, spirothiran, naphthylpyran, rhodamine, and oxazine.

[0013] Optionally, the optical response signal includes a fluorescence signal with a wavelength greater than or equal to 610 nm and less than or equal to 650 nm.

[0014] In one embodiment, a stress-sensitive material layer is prepared on the surface of the encapsulation substrate, including:

[0015] The metronic fluorescent material is dispersed in a solvent to obtain a mixed solution;

[0016] The mixed solution is coated onto at least a portion of the surface of the encapsulation substrate to obtain a stress-sensitive material layer.

[0017] Optionally, coating the mixed solution onto at least a portion of the surface of the encapsulation substrate includes:

[0018] Under ultrasonic assistance, the mixed solution is coated onto at least a portion of the surface of the encapsulation substrate.

[0019] Optionally, the ultrasound meets at least one of the following conditions:

[0020] The frequency is greater than or equal to 35 kHz and less than or equal to 45 kHz;

[0021] Power greater than or equal to 40 W and less than or equal to 60 W;

[0022] The time is greater than or equal to 3 seconds and less than or equal to 8 seconds.

[0023] Optionally, the time required to coat at least a portion of the surface of the encapsulation substrate with the mixed solution is greater than or equal to 25 s and less than or equal to 35 s.

[0024] Optionally, the coating includes at least one of dip coating and spin coating.

[0025] Optionally, in the mixed solution, the concentration of the metronome fluorescent material is greater than or equal to 0.5 mmol / L and less than or equal to 1.5 mmol / L.

[0026] Optionally, the thickness of the stress-sensitive material layer is greater than or equal to 3 nm and less than or equal to 8 nm.

[0027] In one embodiment, after fabricating a stress-sensitive material layer on the surface of the encapsulation substrate, and before acquiring the optical response signal of the stress-sensitive material layer under the stress field in the first region, the method further includes:

[0028] The stress-sensitive material layer is pre-activated using light of the first wavelength.

[0029] Optionally, the first wavelength of light includes ultraviolet light.

[0030] Optionally, the pre-activation process takes a time greater than or equal to 5 seconds and less than or equal to 15 seconds.

[0031] Optionally, when the mechanical stress in the first region exceeds the second threshold, the pre-activated stress-sensitive material layer at the corresponding location generates a fluorescent group.

[0032] Optionally, the second threshold is less than or equal to 100 MPa.

[0033] In one embodiment, when the mechanical stress at a first location in the first region exceeds a first threshold, the stress-sensitive material layer corresponding to the first location generates a fluorescent group.

[0034] Acquiring the optical response signal of the stress-sensitive material layer under the stress field in the first region includes:

[0035] The stress-sensitive material layer corresponding to the first position is irradiated with light of a second wavelength, and the stress-sensitive material layer produces fluorescence, the second wavelength being shorter than the fluorescence wavelength;

[0036] Fluorescence is collected using a fluorescence detector to obtain the optical response signal.

[0037] Optionally, the stress-sensitive material layer corresponding to the first position is irradiated with light of the second wavelength for a time greater than or equal to 1 μs and less than or equal to 3 μs.

[0038] Optionally, the optical response signal of the stress-sensitive material layer under the stress field in the first region is acquired, including:

[0039] The optical response signals of the stress-sensitive material layer under the stress fields in the first and second regions are obtained.

[0040] In one embodiment, determining stress distribution information on the packaging substrate based on the optical response signal includes:

[0041] Based on the intensity distribution characteristics of the optical response signal, at least one of the following on the packaging substrate is identified: stress concentration region, microcrack tip, and structural distortion. The ratio of the optical response signal intensity of the stress concentration region to that of the non-stress concentration region is greater than or equal to N, and N is greater than or equal to 3.

[0042] Optionally, after determining the stress distribution information on the packaging substrate based on the optical response signal, the method further includes:

[0043] A defect risk assessment is performed on the packaging substrate based on the number of identified stress concentration areas; and / or, a defect risk assessment is performed on the packaging substrate based on the intensity of the optical response signal of the identified stress concentration areas.

[0044] In one embodiment, a packaging substrate is provided, comprising:

[0045] A laser is used to modify the packaging substrate material layer to obtain a packaging substrate including at least one modified region. The modified region penetrates the packaging substrate material layer in a direction perpendicular to the packaging substrate material layer. The first region includes at least one modified region, and the second region includes the packaging substrate material layer that has not been modified.

[0046] And / or, provide a packaging substrate, including:

[0047] Laser treatment is used to modify the encapsulation substrate material layer to obtain at least one modified region;

[0048] At least one modified region is removed to obtain a packaging substrate including multiple through holes, wherein the through holes penetrate the packaging substrate material layer in a direction perpendicular to the packaging substrate material layer; a first region includes the sidewalls of the through holes, and a second region includes the packaging substrate material layer that has not undergone modification treatment.

[0049] Optionally, the material of the encapsulation substrate layer may include glass.

[0050] Optionally, within 5 minutes of providing the encapsulation substrate, a stress-sensitive material layer is prepared on the surface of the encapsulation substrate.

[0051] Optionally, the stress distribution detection method further includes:

[0052] The laser parameters are adjusted based on the stress distribution information.

[0053] A second aspect of this disclosure provides a stress distribution detection system, comprising:

[0054] A substrate carrier unit is used to carry a packaging substrate. The packaging substrate includes a first region and a second region. The stress in at least a portion of the first region is greater than the stress in the second region. The first region penetrates the packaging substrate in a direction perpendicular to the packaging substrate.

[0055] A material application unit is configured to apply a stress-sensitive material layer to the surface of a packaging substrate, the stress-sensitive material layer covering at least a first region; the optical properties of the stress-sensitive material layer change with the applied mechanical stress;

[0056] An optical detection unit is configured to acquire the optical response signal of the stress-sensitive material layer under the action of a stress field in the first region;

[0057] The processing unit is configured to determine stress distribution information on the packaging substrate based on the optical response signal.

[0058] In one embodiment, the material application unit includes an immersion tank and an ultrasonic generator.

[0059] Optionally, the optical detection unit includes an excitation source and a fluorescence signal detector.

[0060] Optionally, the processing unit is also configured to identify stress concentration areas and perform defect risk assessment based on the intensity distribution characteristics of the optical response signal.

[0061] Optionally, the stress distribution detection system also includes:

[0062] The laser modification unit is configured to generate laser light, modify the encapsulation substrate material layer, and adjust parameters based on stress distribution information identified by the processing unit.

[0063] Optionally, the stress distribution detection system also includes:

[0064] Manufacturing execution unit, used to store stress distribution information on the packaging substrate.

[0065] The third aspect of this disclosure provides an apparatus for manufacturing a packaging substrate, including the stress distribution detection system provided in the second aspect.

[0066] According to the stress distribution detection method provided in this disclosure, the stress in the first region of the encapsulation substrate is relatively high. Because the stress distribution in the first and second regions differs, the optical response signals in the stress-sensitive material layer also differ. Therefore, based on the optical response signals, the stress distribution information on the encapsulation substrate can be determined, converting the invisible residual stress information inside the encapsulation substrate into a light signal that can be detected by an optical system. This achieves non-contact, visualization, and localization of the residual stress field in the first region. Furthermore, the stress distribution detection method of this disclosure can effectively warn of potential cracking defects caused by stress concentration and can also provide direct stress distribution feedback information for the fabrication of the encapsulation substrate, thereby optimizing the fabrication parameters or process of the encapsulation substrate. Attached Figure Description

[0067] Figure 1 This is a schematic flowchart of a stress distribution detection method in one embodiment of the present disclosure.

[0068] Figure 2 This is a schematic cross-sectional view of the packaging substrate in one embodiment of the present disclosure.

[0069] Figure 3 This is a schematic diagram of the structure of the packaging substrate provided in one embodiment of the present disclosure.

[0070] Figure 4 This is a schematic cross-sectional view of the encapsulation substrate and stress-sensitive material layer in one embodiment of the present disclosure.

[0071] Figure 5This is a schematic cross-sectional view of the encapsulation substrate and stress-sensitive material layer in another embodiment of this disclosure.

[0072] Figure 6 This is a schematic diagram of a structure in which laser is used to modify the encapsulation substrate material layer in one embodiment of the present disclosure.

[0073] Figure 7 This is a schematic cross-sectional view of the packaging substrate in another embodiment of the present disclosure.

[0074] Figure 8 This is a schematic cross-sectional view of the encapsulation substrate and stress-sensitive material layer in another embodiment of this disclosure.

[0075] Figure 9 This is a schematic cross-sectional view of the encapsulation substrate and stress-sensitive material layer in another embodiment of this disclosure.

[0076] Figure 10 This is a schematic flowchart illustrating a method for preparing a stress-sensitive material layer on the surface of an encapsulation substrate according to one embodiment of the present disclosure.

[0077] Figure 11 This is a schematic flowchart of a stress distribution detection method according to another embodiment of the present disclosure.

[0078] Figure 12 This is a schematic flowchart of a method for obtaining the optical response signal of a stress-sensitive material layer under the action of a stress field in a first region, according to one embodiment of the present disclosure. Detailed Implementation

[0079] The technical solutions of the embodiments of this disclosure will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this disclosure, and not all embodiments. Based on the embodiments of this disclosure, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this disclosure.

[0080] Furthermore, to better illustrate this disclosure, numerous specific details are set forth in the following detailed description. Those skilled in the art will understand that this disclosure can be practiced without certain specific details. In some instances, methods and means well-known to those skilled in the art have not been described in detail in order to highlight the main points of this disclosure.

[0081] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0082] Furthermore, the terms "first" and "second" are used only to distinguish descriptions and should not be interpreted as indicating or implying relative importance.

[0083] Through-Glass Via (TGV) technology has become the next-generation core solution for 3D interconnects, replacing Through-Silicon Via (TSV), due to the advantages of glass substrates: low dielectric loss (Df < 0.005), adjustable coefficient of thermal expansion (CTE 3-9 ppm / ℃), large size (up to 510 mm × 515 mm), and cost. In the TGV manufacturing process, laser-induced wet etching has become the mainstream hole-forming technology due to its advantages of no carbonization, smooth sidewalls, and high aspect ratio. However, laser modification introduces residual stress fields (>100 MPa) into the glass hole walls, and stress concentration leads to the initiation of microcracks (<1 μm). These microcracks propagate during subsequent thermal cycling, causing device failure. In contrast, during TSV manufacturing, cracks are almost nonexistent because the mechanical strength of the silicon substrate is higher than that of the glass substrate.

[0084] In the field of glass packaging substrate manufacturing and quality control, to assess the residual stress and potential risks introduced by laser modification in the packaging substrate, related technologies typically employ methods that rely on physical cracks or macroscopic morphological changes to generate detection signals. Specifically, these include fluorescence staining, online optical inspection, Raman spectroscopy, and cross-sectional analysis. The basic principle of fluorescence staining is to capture the difference in dye adsorption by formed microcracks and identify defects through intensity differences. This method can only detect cracked areas, providing no signal for stress-concentrated but uncracked areas, making it impossible to quantify stress magnitude, and the crack tip positioning accuracy is greater than 2 μm. The basic principle of online optical inspection is to use a high-speed linear array camera (5 μm resolution) to capture bright-field and dark-field images of the via opening, identifying refractive index changes in the modified area through polarization and phase difference to observe abnormal changes in the via opening morphology. However, it can only detect the via opening morphology, completely obscuring microcracks, roughness, and elliptical necks in the via wall. When the aspect ratio is greater than 5:1, information within the via is completely unavailable, making it impossible to quantitatively assess defects within the via. The basic working principle of Raman spectroscopy is to measure the stress-induced peak shifts of chemical bonds in materials and calculate the stress magnitude through the Si-O bond peak shifts. However, this method produces extremely weak signals, with integration times greater than 30 seconds at each site and a resolution greater than 5 μm. It cannot locate microcracks smaller than 1 μm and cannot perform whole-section scanning. The basic working principle of cross-sectional analysis is to cut a cross-section of the prepared packaging substrate and observe the hole wall cracks and roughness using a scanning electron microscope. The stress state is indirectly inferred by directly observing the physical defects of the cross-section. This method is destructive testing, cannot detect closed microcracks, can only observe two-dimensional cross-sections, and cannot obtain three-dimensional stress fields; single-hole preparation takes more than 30 minutes. In summary, current methods can only detect existing macroscopic cracks, have no ability to detect stress concentration areas, and cannot provide early warning of defects.

[0085] In view of this, the first aspect of this disclosure provides a method for detecting stress distribution, referring to... Figure 1 The diagram shows a flow chart of a stress distribution detection method, which includes the following steps.

[0086] S100: Provides a packaging substrate.

[0087] For example, refer to Figure 2 The schematic diagram of the cross-sectional structure of the encapsulation substrate shown shows that the encapsulation substrate 100 includes a first region 110 and a second region 120. The stress of at least a portion of the first region 110 is greater than the stress of the second region 120. The first region 110 penetrates the encapsulation substrate 100 in a direction perpendicular to the encapsulation substrate 100.

[0088] S200: A stress-sensitive material layer is prepared on the surface of the encapsulation substrate, the stress-sensitive material layer covering at least the first region.

[0089] For example, the optical properties of the stress-sensitive material layer vary with the mechanical stress applied to the stress-sensitive material layer.

[0090] For example, the stress-sensitive material layer 200 covers the first region 110 and the second region 120.

[0091] S300: Acquire the optical response signal of the stress-sensitive material layer under the stress field in the first region.

[0092] S400: Determines stress distribution information on the packaging substrate based on optical response signals.

[0093] According to the stress distribution detection method provided in this disclosure, the stress in the first region 110 of the encapsulation substrate 100 is relatively large. Because the stress distribution in the first region 110 and the second region 120 is different, the optical response signals in the stress-sensitive material layer 200 are also different. Therefore, based on the optical response signals, the stress distribution information on the encapsulation substrate 100 can be determined, converting the invisible residual stress information inside the encapsulation substrate 100 into a light signal that can be detected by the optical system. This achieves non-contact, visualization, and localization of the residual stress field in the first region 110. Furthermore, the stress distribution detection method of this disclosure can effectively warn of potential cracking defects caused by stress concentration and can also provide direct stress distribution feedback information for the fabrication of the encapsulation substrate 100, thereby optimizing the fabrication parameters or process of the encapsulation substrate 100.

[0094] In one embodiment, refer to Figure 3 The steps of providing the encapsulation substrate include: using a laser S (the dashed line in the figure indicates a laser beam) to modify the encapsulation substrate material layer to obtain an encapsulation substrate 100 including at least one modified region 11, wherein the modified region 11 penetrates the encapsulation substrate material layer in a direction perpendicular to the encapsulation substrate material layer; a first region 110 including at least one modified region 11, and a second region 120 including an unmodified encapsulation substrate material layer.

[0095] It is understandable that the stress in modified region 11 is greater than the stress in the second region 120.

[0096] For example, refer to Figure 4 and Figure 5 The schematic diagram of the cross-sectional structure of the encapsulation substrate and the stress-sensitive material layer shown illustrates that, along the direction perpendicular to the encapsulation substrate 100, the stress-sensitive material layer 200 is located on one side of the surface of the encapsulation substrate 100 (refer to...). Figure 4 Alternatively, the stress-sensitive material layer 200 is located on opposite surfaces of the encapsulation substrate 100 (see reference). Figure 5 ).

[0097] Optionally, the stress distribution detection method further includes adjusting the laser parameters based on the stress distribution information. Thus, the detected stress distribution information reacts to the laser parameters, facilitating the formation of a closed-loop process, improving the yield of the packaging substrate, reducing uneven stress distribution, stress concentration, or microcracks during manufacturing, and lowering production costs.

[0098] In another embodiment, the step of providing the encapsulation substrate includes: modifying the encapsulation substrate material layer using a laser S to obtain at least one modified region 11 (refer to...). Figure 6 At least one modified region 11 is removed to obtain a packaging substrate 100 including a plurality of through holes 11a, wherein the through holes 11a penetrate the packaging substrate material layer in a direction perpendicular to the packaging substrate material layer; a first region 110 includes the sidewalls of the through holes 11a, and a second region 120 includes the unmodified packaging substrate material layer (see reference). Figure 7 ).

[0099] For example, when the modified region is removed using wet etching, the residual stress field (>100 MPa) in the modified region is most complete after laser modification and before wet etching, and the stress concentration area has not yet been etched away. Spiropyran molecules self-assemble on the stressed glass surface through van der Waals forces, and mechanical force induces ring-opening isomerism, converting the stress signal into a 620nm fluorescence signal. This allows for the identification of stress concentration areas before wet etching, intercepting defective wafers and avoiding unnecessary etching costs. The stress threshold for ring-opening of spiropyran molecules under stress is 100MPa-150 MPa, matching the glass fracture stress. In a specific example, the false alarm rate is less than 5% when using the stress distribution detection method of this embodiment to detect the packaging substrate.

[0100] For example, the laser includes a green laser or an ultraviolet laser, and the pulse width of the laser includes at least one of nanosecond, picosecond, and femtosecond.

[0101] For example, the number of vias 11a in the packaging substrate 100 is 30,000 to 300,000, the diameter of the vias 11a is 30 μm to 50 μm, and the depth of the vias 11a is 300 μm to 700 μm.

[0102] For example, the preparation of the encapsulation substrate 100 can be carried out in a nitrogen atmosphere to avoid oxidation contamination on the surface of the encapsulation substrate.

[0103] For example, after obtaining the modified region, the encapsulation substrate is not cleaned or etched to maintain the integrity of the stress field, and a stress-sensitive material layer is prepared on the surface of the encapsulation substrate within 5 minutes.

[0104] For example, refer to Figure 8 and Figure 9The schematic diagram of the cross-sectional structure of the encapsulation substrate and the stress-sensitive material layer shown illustrates that, along the direction perpendicular to the encapsulation substrate 100, the stress-sensitive material layer 200 is located on one side surface of the encapsulation substrate 100 and on the sidewall of the through-hole 11a (see reference). Figure 8 Alternatively, the stress-sensitive material layer 200 may be located on the surfaces of opposite sides of the encapsulation substrate 100 and on the sidewalls of the via 11a (see reference). Figure 9 ).

[0105] It is understandable that the stress on the sidewall of the through hole 11a is greater than the stress in the second region 120.

[0106] Optionally, the stress distribution detection method further includes adjusting the laser parameters based on the stress distribution information. Thus, the detected stress distribution information, in turn, influences the adjustment of the laser parameters, facilitating the formation of a closed-loop process, improving the yield of the packaging substrate, reducing uneven stress distribution or stress concentration during manufacturing, and lowering production costs.

[0107] Optionally, the encapsulation substrate material layer may be made of glass. It is understood that after laser modification of the glass to obtain modified region 11, the stress in modified region 11 is relatively high. When the stress in modified region 11 exceeds the fracture strength or fracture toughness of the glass, the chemical bonds in the glass network structure cannot withstand the stress and break. Simultaneously, the defects, interfaces, and density inhomogeneities within modified region 11 provide preferential sites for crack nucleation, ultimately spontaneously introducing microcracks within the glass to release internal stress and reduce system energy. It is understood that the sidewalls of the glass through-hole 11a have high internal stress, and the sidewall surface is rough with microscopic uneven structures, easily leading to stress concentration. Glass is a brittle material and cannot release stress through plastic deformation. When the local stress on the sidewall exceeds the fracture strength or fracture toughness of the glass, the chemical bonds in the glass network structure break. Simultaneously, structural defects in the sidewall region provide preferential sites for crack nucleation, thereby introducing microcracks into the glass. When stress concentration occurs in the glass encapsulation substrate 100, there may be no obvious cracks or even no cracks at all. When a metal layer is deposited in the through-hole 11a of the encapsulation substrate 100 or an organic layer or a non-polar layer is fabricated on the surface of the encapsulation substrate 100, stress concentration can easily lead to fragmentation of the encapsulation substrate 100, thereby affecting the yield of the encapsulation carrier. Therefore, it is necessary to identify whether stress concentration exists in the encapsulation substrate 100 before depositing a metal layer in the through-hole 11a or fabricating an organic layer or a non-polar layer on the surface of the encapsulation substrate 100, so as to avoid material loss, decreased yield, and additional costs in subsequent film fabrication processes.

[0108] In one embodiment, the stress-sensitive material layer 200 includes a mechanoluminescent material. For example, a mechanoluminescent material refers to a class of materials that can generate or enhance fluorescence under external forces (tension, compression, friction, impact, shear, etc.).

[0109] Optionally, when the mechanical stress in the first region 110 exceeds a first threshold, the stress-sensitive material layer 200 at the corresponding location generates a fluorescent group. For example, when the mechanical stress at the first position Q1 of the first region 110 exceeds the first threshold, the stress-sensitive material layer 200 at the first position Q1 generates a fluorescent group.

[0110] For example, the mechanical stress in the first region 110 includes, but is not limited to, tensile stress and shear stress.

[0111] Optionally, the first threshold is less than or equal to 150 MPa, for example, it can be 150 MPa, 140 MPa, 130 MPa, 120 MPa, 110 MPa, 100 MPa, 90 MPa, 80 MPa, 70 MPa, 60 MPa, etc. It can be understood that the smaller the first threshold, the more readily the stress-sensitive material layer 200 can generate fluorescent groups under relatively small mechanical stress, which helps to improve the sensitivity of stress distribution detection and provides a stronger early warning capability.

[0112] Optionally, the metronic fluorescent material comprises at least one of spiropyran, spirothiran, naphthylpyran, rhodamine, and oxazine.

[0113] For example, spiropyran can generate fluorescent groups by ring opening under stress of around 150 MPa. 150 MPa matches the glass fracture stress, which is beneficial for reflecting the stress distribution in the early warning packaging substrate.

[0114] For example, spiropyran (SP) undergoes ring-opening under mechanical stress in region 110, breaking the CO bond and forming a planar conjugated zwitterionic structure, yielding the fluorophore merocyanine (MC). When the fluorophore is irradiated with light at excitation wavelengths of 532 nm or 633 nm, the fluorescence emitted by the fluorophore ranges from 610 nm to 670 nm.

[0115] For example, spirothio pyran undergoes ring-opening under mechanical stress in region 110, resulting in the CS bond breaking and yielding thiocyanine. The fluorescence emitted by the fluorophore when excited by light at excitation wavelengths of 488 nm or 514 nm ranges from 520 nm to 580 nm.

[0116] For example, under mechanical stress in region 110, naphthopyran undergoes ring-opening, breaking the CO bond to yield naphthohomerocyanine. The fluorescence emitted by the fluorophore when excited by light at excitation wavelengths of 488 nm or 514 nm ranges from 500 nm to 580 nm.

[0117] For example, rhodamine undergoes ring-opening under mechanical stress in region 110, resulting in the cleavage of the spironolactone CN bond and planarization of the xanthracene core, yielding the rhodamine cation. The fluorescence emitted by the fluorophore under excitation at 532 nm or 555 nm ranges from 570 nm to 630 nm.

[0118] For example, oxazine undergoes ring-opening under mechanical stress in region 110, breaking the spiro-CO bond to form a planar conjugated cation, yielding an oxazine cation. The fluorescence emitted by the fluorophore when excited by light at excitation wavelengths of 488 nm or 514 nm ranges from 490 nm to 550 nm.

[0119] For example, the optical response signal generally refers to any form of optical signal change that can be captured by an optical detection system, generated by a stress-sensitive material layer after being subjected to a residual stress field from the encapsulation substrate. This signal directly or indirectly characterizes the magnitude, distribution, or change of the mechanical stress acting on the stress-sensitive material layer. For example, the optical response signal may include, but is not limited to: fluorescence or phosphorescence signals emitted by the stress-sensitive material layer after excitation, whose intensity, wavelength, or polarization state changes with stress; spectral signals generated by changes in the reflectance or transmittance of the stress-sensitive material layer under specific wavelength illumination due to stress-induced color center formation or energy level transitions; or time-domain decay signals corresponding to changes in the luminescence lifetime of the stress-sensitive material caused by stress. The optical response signal can be acquired through point scanning, line scanning, or area array imaging using devices such as confocal microscopes, spectrometers, photomultiplier tubes, or area array cameras. In one specific embodiment, the optical response signal includes fluorescence signals with wavelengths greater than or equal to 610 nm and less than or equal to 650 nm. For example, the mechanoluminescent material is spiropyran.

[0120] Optionally, within 5 minutes of providing the encapsulation substrate, a stress-sensitive material layer is prepared on the surface of the encapsulation substrate. This helps prevent stress relaxation and improves the accuracy of stress distribution detection.

[0121] In one embodiment, refer to Figure 10 The process of preparing a stress-sensitive material layer on the surface of a packaging substrate includes the following steps.

[0122] S210: Disperse the metronome fluorescent material in a solvent to obtain a mixed solution.

[0123] For example, the solvent includes ethanol. For example, the mixed solution should be stored away from light to prevent premature activation by ultraviolet light.

[0124] Optionally, the concentration of the metronic fluorescent material in the mixed solution is greater than or equal to 0.5 mmol / L and less than or equal to 1.5 mmol / L, for example, it can be 0.5 mmol / L, 0.7 mmol / L, 0.9 mmol / L, 1 mmol / L, 1.1 mmol / L, 1.3 mmol / L or 1.5 mmol / L, etc.

[0125] For example, 1 mmol / L is equal to 1 mM.

[0126] S220: The mixed solution is coated on at least a portion of the surface of the encapsulation substrate to obtain a stress-sensitive material layer.

[0127] Optionally, coating the mixed solution onto at least a portion of the surface of the encapsulation substrate includes: coating the mixed solution onto at least a portion of the surface of the encapsulation substrate with ultrasound assistance. Thus, ultrasound facilitates the uniform formation of mechanoluminescent material on the surface of the encapsulation substrate; when the encapsulation substrate has through-holes, ultrasound can promote air expulsion and molecular permeation within the through-holes, thereby enabling the uniform formation of mechanoluminescent material on the sidewalls of the through-holes.

[0128] For example, spiropyran molecules self-assemble on the glass surface of the encapsulation substrate via van der Waals forces.

[0129] It is understandable that coating the mixed solution onto at least a portion of the surface of the encapsulation substrate is a simple process that does not require atomic layer deposition or chemical vapor deposition.

[0130] Optionally, the ultrasound meets at least one of the following conditions: frequency greater than or equal to 35 kHz and less than or equal to 45 kHz (e.g., 35 kHz, 37 kHz, 39 kHz, 41 kHz, 43 kHz, or 45 kHz, etc.); power greater than or equal to 40 W and less than or equal to 60 W (e.g., 40 W, 45 W, 50 W, 55 W, or 60 W, etc.); and duration greater than or equal to 3 s and less than or equal to 8 s (e.g., 3 s, 4 s, 5 s, 6 s, 7 s, or 8 s, etc.). Thus, the frequency and power of the ultrasound are appropriate, and it is unlikely to cause breakage of the glass encapsulation substrate.

[0131] Optionally, the time required to coat the mixed solution onto at least a portion of the surface of the encapsulation substrate is greater than or equal to 25 s and less than or equal to 35 s (e.g., 25 s, 27 s, 29 s, 31 s, 33 s, or 35 s, etc.).

[0132] Optionally, the coating includes at least one of dip coating and spin coating. In a preferred example, the coating is performed by dip coating. Thus, the mechanoluminescent material is uniformly formed on the surface of the first region (e.g., the surface of the modified region or the sidewall of the via).

[0133] Optionally, the thickness of the stress-sensitive material layer 200 is greater than or equal to 3 nm and less than or equal to 8 nm (for example, it can be 3 nm, 4 nm, 5 nm, 6 nm, 7 nm, or 8 nm, etc.). Thus, the stress-sensitive material layer 200 can completely cover the first region 110, and there will be almost no exposure of the first region 110, which is beneficial to improving the accuracy of stress distribution detection.

[0134] For example, when the encapsulation substrate has through holes, the stress-sensitive material layer 200 has a coverage of 95% or more on the sidewall of the through hole.

[0135] In one embodiment, refer to Figure 11 After preparing a stress-sensitive material layer on the surface of the encapsulation substrate, and before acquiring the optical response signal of the stress-sensitive material layer under the stress field in the first region, the following steps are also included.

[0136] S500: Pre-activate the stress-sensitive material layer with light of the first wavelength.

[0137] Optionally, the first wavelength of light includes ultraviolet light. When the mechanical stress in the first region exceeds a second threshold, the pre-activated stress-sensitive material layer at the corresponding location generates a fluorescent group. The second threshold is less than the first threshold. For example, the second threshold is less than or equal to 100 MPa, such as 100 MPa, 90 MPa, 80 MPa, 70 MPa, 60 MPa, etc.

[0138] Optionally, the pre-activation processing time is greater than or equal to 5 s and less than or equal to 15 s (e.g., it can be 5s, 8s, 10s, 12s or 15s, etc.).

[0139] For example, irradiating a stress-sensitive material layer with 365 nm ultraviolet light for 10 seconds causes the spiropyran in the layer to transition from a stable state to a metastable state (the metastable state can include an open-ring oxobutane structure). At this point, the spiropyran's response rate to mechanical forces increases, and the mechanical force required to generate the fluorescent group decreases from 150 MPa to 100 MPa or even lower. This allows for the detection of potential risk areas with lower stress levels, enhancing early warning capabilities. In a specific example, the probability of detecting stress concentration locations in the encapsulation substrate using spiropyran is greater than or equal to 98%.

[0140] In a specific example, a uniform array of ultraviolet (UV) light-emitting diodes (LEDs) is used to irradiate the spiropyran-containing stress-sensitive material layer. The center wavelength of the UV LEDs is, for example, 365 nm. The irradiation time is 10 seconds. This process causes the spiropyran molecules to transform from a stable closed-ring state (SP) to a metastable open-ring anthocyanin state (MC). This MC state is more sensitive to stress; lower mechanical stress can induce it to stabilize in a strongly fluorescent state, thereby reducing the system's detection threshold from approximately 150 MPa to approximately 100 MPa. This allows the stress distribution detection method to detect lower levels of residual stress, enhancing its early warning capability. The activated state can be maintained for approximately 30 minutes in a dark environment at room temperature, providing a sufficient time window for scanning and detecting the entire packaged substrate. Detection is completed within 30 minutes in a dark environment at room temperature after activation, preventing thermal relaxation from causing a decrease in sensitivity.

[0141] In one embodiment, when the mechanical stress at a first location Q1 in the first region 110 exceeds a first threshold, the stress-sensitive material layer 200 corresponding to the first location Q1 generates a fluorescent group. (Refer to...) Figure 12 Obtaining the optical response signal of the stress-sensitive material layer under the action of the stress field in the first region includes the following steps.

[0142] S310: The stress-sensitive material layer corresponding to the first position is irradiated with light of a second wavelength, and the stress-sensitive material layer generates fluorescence. The second wavelength is shorter than the wavelength of the fluorescence.

[0143] For example, spiropyran undergoes ring-opening under mechanical stress in the first region 110 to obtain a fluorophore. Irradiation of the fluorophore with light at an excitation wavelength of 633 nm produces fluorescence with a wavelength greater than 633 nm. Furthermore, the 633 nm light has almost no effect on spiropyran, improving the accuracy of stress distribution detection.

[0144] Optionally, the time for irradiating the stress-sensitive material layer corresponding to the first position with light of the second wavelength is greater than or equal to 1 μs and less than or equal to 3 μs, for example, it can be 1 μs, 2 μs, or 3 μs. Therefore, the second wavelength of light has a shorter interaction time with the stress-sensitive material layer, resulting in a smaller impact on the layer and improving the accuracy of stress distribution detection. The irradiation time of the stress-sensitive material layer corresponding to the first position with light of the second wavelength can be the integration time; a shorter integration time helps avoid photobleaching.

[0145] S320: A fluorescence detector is used to collect fluorescence and obtain an optical response signal.

[0146] It is understandable that a fluorescence detector can be used to collect fluorescence while irradiating the stress-sensitive material layer corresponding to the first position with light of the second wavelength.

[0147] Optionally, a fluorescence detector can be used to collect fluorescence at multiple sites in the first region, thereby obtaining optical response signals at multiple sites and thus obtaining the stress distribution of the entire first region. The multiple sites can be distributed in an array.

[0148] Optionally, acquiring the optical response signal of the stress-sensitive material layer under the stress field in the first region includes: acquiring the optical response signals of the stress-sensitive material layer under the stress fields in the first and second regions. It is understood that the stress in the second region is less than that in the first region, and the stress-sensitive material layer will hardly generate an optical response signal in the second region. The optical response signal of the stress-sensitive material layer under the stress field in the second region can be used as a background field for comparison with the optical response signal of the stress-sensitive material layer under the stress field in the first region, highlighting the intensity of the optical response signal of the stress-sensitive material layer under the stress field in the first region. Alternatively, if the glass is subjected to external force during laser modification, causing an increase in stress in the second region, the optical response signal of the stress-sensitive material layer under the stress field in the second region may be stronger, which is beneficial for identifying the stress distribution throughout the entire encapsulation substrate and improving the accuracy of stress distribution detection.

[0149] In one embodiment, determining stress distribution information on the packaging substrate based on the optical response signal includes: identifying at least one of stress concentration regions, microcracks, and structural distortions on the packaging substrate based on the intensity distribution characteristics of the optical response signal.

[0150] For example, stress distribution information generally refers to data or images extracted from optical response signals that describe the spatial distribution of residual stress fields on a packaged substrate. Stress distribution information maps optical signals back to mechanical states, enabling the location and assessment of potential defect risk areas. For instance, stress distribution information can be represented as a stress distribution map, where the grayscale value or color at each point represents the relative or absolute value of the stress at that location. Another example is a stress gradient map or principal stress direction map. Yet another example is a data list obtained by further processing the aforementioned stress distribution map, which calibrates the coordinates of stress concentration areas and the magnitude of stress peaks. Stress distribution information can be quantified by comparing the optical signal intensity with a pre-calibrated stress-optical response curve, or qualitatively identified by analyzing the spatial distribution characteristics of the signal intensity (such as gradients and discontinuities).

[0151] For example, the ratio of the optical response signal intensity in the stress concentration region to that in the non-stress concentration region is greater than or equal to N, and N is greater than or equal to 3 (e.g., it can be 3, 4, or 5, etc.).

[0152] For example, the optical response signal is fluorescence. In the stress concentration region, the fluorescence intensity is more than three times the average fluorescence intensity in the non-stress concentration region, and the fluorescence intensity exhibits a gradient distribution. In the stress concentration region, even if no visible cracks are observed, the stress concentration region is still identified as a high-risk area.

[0153] For example, the optical response signal is fluorescence, and a microcrack refers to a sequence of fluorescent bright spots arranged in a specific direction, which represents the crack propagation path. The location of the fluorescent bright spots is either the tip of the microcrack or the tip of the crack itself.

[0154] For example, structural distortion includes at least one of edge chipping and ellipticization. Exemplarily, the optical response signal is fluorescence, the modified region is cylindrical, and the fluorescence emitted from the stress-sensitive material layer corresponding to the edge of the modified region is circular. If the fluorescence ring at the neck is discontinuous, it is determined to be an edge chipping defect; if the fluorescence intensity of the fluorescence ring changes abruptly, it is determined to be ellipticization of the through-hole structure. It should be noted that the neck refers to the transition position between the hole opening and the hole wall, or the transition position between the modified region and the unmodified region.

[0155] Optionally, after determining the stress distribution information on the packaging substrate based on the optical response signal, the method further includes the following steps: assessing the defect risk of the packaging substrate based on the number of identified stress concentration areas; or assessing the defect risk of the packaging substrate based on the intensity of the optical response signal of the identified stress concentration areas.

[0156] For example, if there are no stress concentration areas in the packaging substrate, the packaging substrate is a qualified product. If the packaging substrate contains 1 to 3 stress concentration areas, the quality of the packaging substrate needs to be monitored. If the number of stress concentration areas in the packaging substrate is greater than 3, or if there are microcracks in the stress-sensitive material layer, the packaging substrate is a defective product.

[0157] It is understandable that the detected stress distribution information reacts to the parameters of the laser used to create the modified area. The laser parameters can be adjusted to reduce the number of stress concentration areas in the packaging substrate or avoid microcracks, which is conducive to forming a closed loop in the process, improving the manufacturing yield of the packaging substrate, reducing uneven stress distribution, stress concentration or microcracks during the manufacturing process, and reducing production costs.

[0158] For example, the stress distribution detection method of this disclosure can realize early warning of stress concentration in glass substrates, detect dangerous areas that have not yet cracked but have stress greater than 100 MPa, and identify dangerous areas in glass substrates before etching modified areas in glass substrates, thus greatly improving reliability.

[0159] For example, a mechanoluminescent material (e.g., spiropyran) is self-assembled onto the surface of an encapsulation substrate. Utilizing the property that the mechanoluminescent material undergoes mechanophore-induced ring-opening isomerism (mechanophore response) at stresses greater than or equal to 100 MPa, transitioning from a dark state (no fluorescence) to a bright state (emitting 620 nm red light), the material is pre-activated by 365 nm ultraviolet light to enter a stress-sensitive state. Then, the fluorescence signal in the stress concentration area is captured using a confocal microscope, achieving three-dimensional mapping of the stress field and sub-micron localization of the microcrack tip. The accuracy of microcrack localization can be adjusted by changing the type of mechanoluminescent material. For example, spiropyran has a molecular size of 0.8 nm to 1.2 nm, and the stress distribution detection method of this embodiment has a microcrack localization accuracy of less than or equal to 1 μm, exhibiting high precision.

[0160] For example, the stress distribution detection method of this disclosure can quantify the stress distribution of the hole wall by fluorescence intensity gradient, identify weak areas of stress concentration, and provide a data closed loop for laser process optimization.

[0161] For example, the stress distribution detection method of this disclosure can detect hole distortion with high sensitivity. For discontinuities or abrupt changes in intensity of the fluorescent ring in the waist and neck, corresponding to edge breakage or ellipticization, the detection sensitivity is 10 times higher than that of a profilometer.

[0162] For example, the packaging substrate obtained after stress distribution detection using the embodiments of this disclosure can be used for automotive-grade through-hole glass adapter packaging, aerospace-grade through-hole glass adapter packaging, panel-level through-hole glass adapter carrier, optoelectronic co-packaging (CPO), microelectromechanical systems and sensors, radio frequency and millimeter wave modules, and high bandwidth memory (HBM).

[0163] A second aspect of this disclosure provides a stress distribution detection system, comprising: a substrate support unit, a material application unit, an optical detection unit, and a processing unit.

[0164] For example, the substrate carrier unit is used to carry the packaging substrate.

[0165] For example, the encapsulation substrate includes a first region and a second region, at least a portion of the stress in the first region is greater than the stress in the second region, and the first region penetrates the encapsulation substrate in a direction perpendicular to the encapsulation substrate.

[0166] It should be noted that the packaging substrate is the same as described above, and will not be repeated here.

[0167] For example, the substrate carrier unit is used to carry and provide a packaging substrate that has been laser modified but has not yet been wet etched.

[0168] For example, the material application unit is configured to apply a stress-sensitive material layer to the surface of the encapsulation substrate, the stress-sensitive material layer covering at least a first region; the optical properties of the stress-sensitive material layer change with the mechanical stress applied.

[0169] It should be noted that the stress-sensitive material layer is consistent with the previous description, and will not be elaborated further here.

[0170] For example, the material application unit can be a spin coater, which spin coats a mixed solution containing mechanoluminescent material onto at least one surface of the encapsulation substrate to obtain a stress-sensitive material layer. Alternatively, the material application unit can be a dip-coating tank, in which a mixed solution containing mechanoluminescent material is placed, and at least one surface of the encapsulation substrate is immersed in the mixed solution to obtain a stress-sensitive material layer.

[0171] For example, the material application unit includes an immersion coating tank and an ultrasonic generator, the ultrasonic generator being integrated into the bottom or sidewall of the tank. Applying ultrasonic assistance during the immersion coating of the mixed solution facilitates the obtaining of a uniform stress-sensitive material layer.

[0172] It should be noted that ultrasound-assisted treatment is consistent with the previous description, and will not be elaborated further here.

[0173] For example, the material application unit is connected to the substrate support unit.

[0174] For example, the optical detection unit is configured to acquire the optical response signal of the stress-sensitive material layer under the action of a stress field in the first region.

[0175] For example, when acquiring optical response signals, the packaging substrate is placed on the substrate carrier unit.

[0176] For example, the optical detection unit can be a confocal microscope or a high-resolution fluorescence imaging system, with the objective lens aligned with the substrate on the substrate carrier unit.

[0177] It should be noted that the optical response signal is consistent with the previous description, and will not be elaborated further here.

[0178] In one embodiment, the optical detection unit includes an excitation source (such as a 633 nm HeNe laser) and a fluorescence signal detector (such as a photomultiplier tube or a charge-coupled device (CCD) camera). The light emitted by the excitation source is used to excite the phosphors in the stress-sensitive material layer to emit fluorescence, and the fluorescence signal detector is used to detect the fluorescence.

[0179] For example, the gain of the photomultiplier tube can be 700V~900V, such as 700V, 800V or 900V.

[0180] For example, the processing unit is configured to determine stress distribution information on the packaging substrate based on the optical response signal.

[0181] For example, the processing unit can be an industrial computer.

[0182] Optionally, the processing unit is also configured to identify stress concentration areas and perform defect risk assessment based on the intensity distribution characteristics of the optical response signal.

[0183] In a specific example, the processing unit receives Z-stacked three-dimensional fluorescence image data from a confocal microscope. The processing unit operates as follows: First, image preprocessing (such as denoising and background subtraction) is performed. Then, the fluorescence intensity of each site or local region in the image is calculated, and the spatial distribution of fluorescence is analyzed. The identification module operates according to preset rules; for example, it marks regions with fluorescence intensity values ​​exceeding three times the average intensity of the entire region as bright areas. Further analysis of the morphology and gradient of these bright areas reveals that if the bright areas are dot-like with large intensity gradients, they may correspond to microcrack tips; if the bright areas are planar with a clear intensity gradient direction, they correspond to stress concentration areas; and if the annular fluorescence signal at the waist of the through-hole shows discontinuity or abrupt intensity changes, it corresponds to hole distortion (edge ​​chipping or ellipticization). This series of automated image processing and decision-making steps efficiently transforms the raw optical signals into defect risk assessment results that can be directly used for production control.

[0184] For example, the processing unit is connected to the optical detection unit. The processing unit can determine the stress distribution information on the packaging substrate based on the received optical response signal image, and further identify stress concentration areas and perform defect risk assessment.

[0185] For example, defect risk assessment results include: when there are no stress concentration areas in the packaging substrate, the packaging substrate is a qualified product, and the assessment result can be Grade A. When the packaging substrate contains 1 to 3 stress concentration areas, the quality of the packaging substrate needs to be monitored, and the assessment result can be Grade B, which can be used for early warning. When the number of stress concentration areas in the packaging substrate is greater than 3, or there are microcracks in the stress-sensitive material layer, the packaging substrate is a non-qualified product, and the assessment result can be Grade C.

[0186] Optionally, the stress distribution detection system further includes: a laser modification unit configured to generate a laser and modify the encapsulation substrate material layer, and adjust parameters based on the stress distribution information identified by the processing unit.

[0187] It is understood that after modifying the encapsulation substrate material layer, an encapsulation substrate including at least one modified region is obtained.

[0188] It is understandable that the detected stress distribution information reacts to the laser modification unit, which can adjust the laser parameters to reduce the number of stress concentration areas in the packaging substrate or avoid microcracks. This facilitates the formation of a closed loop in the process, improves the manufacturing yield of the packaging substrate, reduces uneven stress distribution, stress concentration or microcracks during the manufacturing process, and lowers production costs.

[0189] Optionally, the stress distribution detection system also includes a Manufacturing Execution System (MES) for storing stress distribution information on the packaging substrate. It can be understood that the laser modification unit can access the stress distribution information from the Manufacturing Execution System, or the Manufacturing Execution System can proactively feed back the stress distribution information to the laser modification unit, automatically triggering laser parameter adjustments.

[0190] For example, a manufacturing line for an automotive-grade panel-level TGV packaging substrate is used as an example. After the laser modification workstation completes the modification scan of hundreds of thousands of vias on a 510mm × 515mm glass packaging substrate, the robotic arm immediately transfers the packaging substrate, which still retains its complete stress field, to the integrated testing station. The testing station first immerses the packaging substrate in a spiropyran-ethanol solution coating tank, while simultaneously initiating 40 kHz ultrasonic assistance for 5 seconds. The substrate is then removed and purged with nitrogen gas (0.2 MPa pressure, 45° angle to remove surface droplets) to remove residual droplets, forming a uniform nanoscale stress-sensitive material layer on the surface of the packaging substrate. Next, an ultraviolet LED array uniformly irradiates the stress-sensitive material layer on the surface of the packaging substrate for 10 seconds to activate the spiropyran molecules. Subsequently, a high-precision substrate carrier unit moves the packaging substrate, and a confocal microscope located above the packaging substrate performs rapid three-dimensional fluorescence scanning of the stress-sensitive material layer on the surface of each modified area (corresponding to the future via location) in Z-stack mode. The raw fluorescence image data obtained from the scan is transmitted to the processing unit in real time. The processing unit completes the processing of the entire substrate's data within minutes, generating a full-board stress distribution heatmap and automatically marking all abnormal fluorescence intensity points (stress concentration areas). Based on preset rules, the system classifies the substrate as Grade B (warning) and records the warning information and the coordinates of the stress concentration points in the MES unit. Simultaneously, the distribution data of these stress concentration points is fed back to the laser modification unit, which then fine-tunes and optimizes the laser scanning speed and power parameters. The pre-warned substrates will enter a special monitoring process for subsequent etching and copper plating, and the final product will undergo more rigorous aging tests. The stress distribution detection method or stress distribution detection system of this disclosure can successfully identify potential risks before etching glass vias, preventing the packaging substrate with hidden stress defects from flowing into expensive back-end photolithography, electroplating and other processes, avoiding ineffective etching costs (for example, saving HF or NaOH consumables and subsequent vapor deposition (PVD) costs), and obtaining key data for closed-loop optimization of direct-drive laser process, thereby improving the overall reliability and manufacturing yield of automotive-grade products.

[0191] The third aspect of this disclosure provides an apparatus for manufacturing a packaging substrate, including the stress distribution detection system provided in the second aspect.

[0192] It should be noted that, in addition to the stress distribution detection system mentioned above, the equipment for preparing the packaging substrate may also include structures that conventional preparation equipment should have, such as wet etching tanks, which will not be elaborated on further here.

[0193] The basic principles of this disclosure have been described above with reference to specific embodiments. However, it should be noted that the advantages, benefits, and effects mentioned in this disclosure are merely examples and not limitations, and should not be considered as essential features of each embodiment of this disclosure. Furthermore, the specific details disclosed above are for illustrative and facilitative purposes only, and are not limitations. These details do not limit the scope of this disclosure to the necessity of employing the aforementioned specific details for implementation.

[0194] The above description has been given for purposes of illustration and description. Furthermore, this description is not intended to limit the embodiments of this disclosure to the forms disclosed herein. Although numerous exemplary aspects and embodiments have been discussed above, those skilled in the art will recognize certain variations, modifications, alterations, additions, and sub-combinations therein.

Claims

1. A method for detecting stress distribution, characterized in that, include: A packaging substrate is provided, the packaging substrate including a first region and a second region, wherein at least a portion of the stress in the first region is greater than the stress in the second region, and the first region penetrates the packaging substrate in a direction perpendicular to the packaging substrate; A stress-sensitive material layer is prepared on the surface of the encapsulation substrate, the stress-sensitive material layer at least covering the first region; The optical properties of the stress-sensitive material layer vary with the mechanical stress applied to the stress-sensitive material layer; Obtain the optical response signal of the stress-sensitive material layer under the stress field in the first region; Based on the optical response signal, the stress distribution information on the packaging substrate is determined; The provided packaging substrate includes: A laser is used to modify the packaging substrate material layer to obtain the packaging substrate including at least one modified region, wherein the modified region penetrates the packaging substrate material layer in a direction perpendicular to the packaging substrate material layer; the first region includes the at least one modified region, and the second region includes the packaging substrate material layer that has not undergone the modification treatment; And / or, the provision of the packaging substrate includes: Laser treatment is used to modify the encapsulation substrate material layer to obtain at least one modified region; The at least one modified region is removed to obtain the packaging substrate including a plurality of through holes, wherein the through holes penetrate the packaging substrate material layer in a direction perpendicular to the packaging substrate material layer; the first region includes the sidewalls of the through holes, and the second region includes the packaging substrate material layer without the modified treatment.

2. The stress distribution detection method according to claim 1, characterized in that, The stress-sensitive material layer includes a mechanoluminescent material; And / or, when the mechanical stress in the first region exceeds a first threshold, the stress-sensitive material layer at the corresponding location generates a fluorescent group.

3. The stress distribution detection method according to claim 2, characterized in that, The first threshold is less than or equal to 150 MPa; And / or, the mechanoluminescent material comprises at least one of spiropyran, spirothiran, naphthylpyran, rhodamine, and oxazine; And / or, the optical response signal includes a fluorescence signal with a wavelength greater than or equal to 610 nm and less than or equal to 650 nm.

4. The stress distribution detection method according to claim 1, characterized in that, The step of preparing a stress-sensitive material layer on the surface of the encapsulation substrate includes: The metronic fluorescent material is dispersed in a solvent to obtain a mixed solution; The mixed solution is coated onto at least a portion of the surface of the encapsulation substrate to obtain the stress-sensitive material layer.

5. The stress distribution detection method according to claim 4, characterized in that, The step of coating the mixed solution onto at least a portion of the surface of the encapsulation substrate includes: The mixed solution is coated onto at least a portion of the surface of the encapsulation substrate under ultrasonic assistance.

6. The stress distribution detection method according to claim 5, characterized in that, The ultrasound meets at least one of the following conditions: The frequency is greater than or equal to 35 kHz and less than or equal to 45 kHz; Power greater than or equal to 40 W and less than or equal to 60 W; The time is greater than or equal to 3 seconds and less than or equal to 8 seconds; And / or, the time required to coat the mixed solution onto at least a portion of the surface of the encapsulation substrate is greater than or equal to 25 s and less than or equal to 35 s; And / or, the coating includes at least one of dip coating and spin coating; And / or, in the mixed solution, the concentration of the mechanoluminescent material is greater than or equal to 0.5 mmol / L and less than or equal to 1.5 mmol / L; And / or, the thickness of the stress-sensitive material layer is greater than or equal to 3 nm and less than or equal to 8 nm.

7. The stress distribution detection method according to claim 1, characterized in that, After fabricating a stress-sensitive material layer on the surface of the encapsulation substrate, and before acquiring the optical response signal of the stress-sensitive material layer under the stress field in the first region, the method further includes: The stress-sensitive material layer is pre-activated using light of a first wavelength.

8. The stress distribution detection method according to claim 7, characterized in that, The first wavelength of light includes ultraviolet light; And / or, the pre-activation process lasts for a period of 5 seconds or more and 15 seconds or less. And / or, when the mechanical stress in the first region exceeds the second threshold, the stress-sensitive material layer after pre-activation treatment at the corresponding location generates a fluorescent group.

9. The stress distribution detection method according to claim 8, characterized in that, The second threshold is less than or equal to 100 MPa.

10. The stress distribution detection method according to claim 1, characterized in that, When the mechanical stress at a first location in the first region exceeds a first threshold, the stress-sensitive material layer corresponding to the first location generates a fluorescent group. The step of acquiring the optical response signal of the stress-sensitive material layer under the stress field in the first region includes: The stress-sensitive material layer corresponding to the first position is irradiated with light of a second wavelength, and the stress-sensitive material layer fluoresces, wherein the second wavelength is shorter than the wavelength of the fluorescence. The fluorescence is collected using a fluorescence detector to obtain the optical response signal; The stress-sensitive material layer corresponding to the first position is irradiated with light of the second wavelength for a time greater than or equal to 1 μs and less than or equal to 3 μs. And / or, acquiring the optical response signal of the stress-sensitive material layer under the stress field in the first region includes: Obtain the optical response signal of the stress-sensitive material layer under the stress field in the first region and the second region; And / or, determining the stress distribution information on the packaging substrate based on the optical response signal includes: Based on the intensity distribution characteristics of the optical response signal, at least one of stress concentration region, microcrack tip and structural distortion on the packaging substrate is identified, wherein the ratio of the intensity of the optical response signal in the stress concentration region to the intensity of the optical response signal in the non-stress concentration region is greater than or equal to N, and N is greater than or equal to 3. And / or, after determining the stress distribution information on the packaging substrate based on the optical response signal, the method further includes: A defect risk assessment is performed on the packaging substrate based on the number of identified stress concentration regions; and / or, a defect risk assessment is performed on the packaging substrate based on the intensity of the optical response signal of the identified stress concentration regions.

11. The stress distribution detection method according to claim 1, characterized in that, The material of the encapsulation substrate layer includes glass; And / or, within 5 minutes of providing the encapsulation substrate, a stress-sensitive material layer is prepared on the surface of the encapsulation substrate; And / or, the stress distribution detection method further includes: Based on the stress distribution information, the parameters of the laser are adjusted.

12. A stress distribution detection system, characterized in that, include: A substrate carrier unit is used to carry a packaging substrate, the packaging substrate including a first region and a second region, the stress in at least a portion of the first region being greater than the stress in the second region, and the first region penetrating the packaging substrate in a direction perpendicular to the packaging substrate; A material application unit is configured to apply a stress-sensitive material layer to the surface of the encapsulation substrate, the stress-sensitive material layer at least covering the first region; The optical properties of the stress-sensitive material layer change with the mechanical stress it is subjected to; An optical detection unit is configured to acquire the optical response signal of the stress-sensitive material layer under the stress field in the first region; The processing unit is configured to determine stress distribution information on the packaging substrate based on the optical response signal.

13. The stress distribution detection system according to claim 12, characterized in that, The material application unit includes an immersion coating tank and an ultrasonic generator; And / or, the optical detection unit includes an excitation light source and a fluorescence signal detector; And / or, the processing unit is further configured to identify stress concentration areas and perform defect risk assessment based on the intensity distribution characteristics of the optical response signal; And / or, the stress distribution detection system further includes: The laser modification unit is configured to generate laser light, modify the encapsulation substrate material layer, and adjust parameters based on the stress distribution information identified by the processing unit. And / or, the stress distribution detection system further includes: Manufacturing execution unit, used to store stress distribution information on the packaging substrate.

14. A manufacturing apparatus for a packaging substrate, characterized in that, Includes the stress distribution detection system as described in claim 12 or 13.

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