Blind hole machining method and substrate

Abstract

The invention relates to the technical field of chip embedded module packaging, in particular to a blind hole processing method and a substrate. An embedded chip substrate is prepared, a chip is embedded in the embedded chip substrate, and the chip is covered with an insulating layer; determining a hole opening position on the insulating layer, wherein the hole opening position corresponds to the embedding position of the chip on the chip embedding substrate; laser ablation is conducted on the hole opening position through ultraviolet laser according to preset laser parameters, so that an initial blind hole is machined in the hole opening position; and performing residue removal processing on the initial blind hole through plasma equipment to obtain a target blind hole. Therefore, the initial blind hole is machined in the hole opening position through the ultraviolet laser, molecular bonds can be directly destroyed, cold ablation is achieved and thermal damage is reduced on the basis of the characteristic that photon energy of the ultraviolet laser is high, meanwhile, the target blind hole with the smooth hole wall can be obtained by conducting residue removing treatment on the initial blind hole through plasma equipment, and the hole opening precision is improved. Compared with the prior art, high-precision and high-quality machining of the blind hole is achieved.

Description

Technical Field

[0001] The present invention relates to the technical field of embedded chip module packaging, and in particular to a blind hole processing method and a substrate. Background Art

[0002] With the rapid advancement of integrated circuit technology, chip integration continues to climb, I / O counts are exploding, and pad pitch is shrinking. Against this backdrop, the limitations of traditional laser blind via processing are becoming increasingly apparent. When the pad pitch shrinks to a certain level, traditional processes struggle to balance the small diameter of the blind via with the quality of its wall. Excessively small apertures significantly increase processing difficulty, while poor wall quality can affect subsequent processes like electroplating, reducing package reliability. Existing technologies are unable to meet the demands for high-precision, high-quality blind via processing, severely hindering the development of embedded chip module packaging.

[0003] Therefore, there is an urgent need to develop new processes to break through traditional limitations and achieve small-diameter, high-quality blind hole processing. Summary of the Invention

[0004] The embodiments of the present invention provide a blind hole processing method and a substrate to solve the problem that when the pad spacing is small, it is difficult to achieve high-precision and high-quality processing of blind holes using traditional processes.

[0005] A blind hole processing method, comprising: A chip-embedded substrate is prepared, wherein a chip is embedded in the chip-embedded substrate and an insulating layer is covered on the chip; Determining a position of an opening on the insulating layer, wherein the position of the opening corresponds to an embedding position of the chip on the embedded chip substrate; Using an ultraviolet laser, laser ablation is performed on the opening position according to preset laser parameters to form an initial blind hole at the opening position; The initial blind hole is subjected to a residual cleaning process by a plasma device to obtain a target blind hole.

[0006] In the above blind hole processing method, optionally, the laser parameters include a first parameter and a second parameter; The laser ablation of the opening position is performed by ultraviolet laser according to preset laser parameters to form an initial blind hole at the opening position, including: Using the ultraviolet laser, according to the first parameters, a first number of first laser ablations are performed on the opening position to form a guide hole at the opening position; The second laser ablation is performed a second time on the opening position by the ultraviolet laser according to the second parameter, so as to process the guide hole into an initial blind hole.

[0007] In the above-mentioned blind hole processing method, optionally, the first parameters include a first laser energy, a first scanning speed and a first pulse width, the first laser energy is less than 1 J / cm², the first scanning speed is 1 to 5 m / s, and the first pulse width is less than or equal to 10 ns; the second parameters include a second laser energy, a second scanning speed and a second pulse width, the second laser energy is 1 to 5 J / cm², the second scanning speed is 1 to 5 m / s, and the second pulse width is less than or equal to 10 ns.

[0008] In the above-mentioned blind hole processing method, optionally, the residue removal process includes etching and passivation; The method of performing a residual cleaning process on the initial blind hole by a plasma device to obtain a target blind hole comprises: The target blind hole is obtained by alternately performing etching treatment and passivation treatment on the initial blind hole using an etching gas and a passivation gas through a plasma device.

[0009] In the above-mentioned blind hole processing method, optionally, the passivation gas used in the passivation treatment includes perfluorocyclobutane; the etching gas used in the etching treatment includes a mixed gas formed by carbon tetrafluoride and oxygen, and the volume ratio of carbon tetrafluoride to oxygen is 4:1.

[0010] The above blind hole processing method, optionally, the preparation of the embedded chip substrate includes: A copper-clad substrate is prepared based on the inner core board and the first copper foil; Performing a build-up process on the copper-clad substrate based on a build-up material and a second copper foil to obtain a build-up substrate; Using a cavity cutting device, cutting a cavity at a preset cutting position on the build-up substrate to obtain a cavity substrate; implanting a chip into the corresponding cavity to obtain a chip substrate; Based on the filling material, the chip substrate is further filled and pressed and baked to obtain the embedded chip substrate.

[0011] The above-mentioned blind hole processing method, optionally, the thickness of the first copper foil is: 18-35um, the thickness of the second copper foil is: 5-12um, the thickness of the build-up material is: 20-50um, the material type of the build-up material is: epoxy resin insulating film, and the dielectric constant of the build-up material is: DK≈3.5.

[0012] In the above-mentioned blind hole processing method, optionally, the working environment of the laser ablation and / or the plasma etching includes: the number of particles greater than or equal to 0.5um in each cubic foot of air is between 1000 and 10000, the ambient temperature is 20-25°C, and the ambient humidity is 40% to 60%.

[0013] In the above-mentioned blind hole processing method, optionally, the plasma parameters of the plasma equipment include: power 200W, chamber pressure 5-20mTorr.

[0014] A substrate comprises a target blind hole, wherein the target blind hole is processed based on the blind hole processing method according to any one of claims 1 to 8.

[0015] The present invention provides a blind hole processing method and substrate. The method comprises preparing an embedded chip substrate, wherein a chip is embedded in the embedded chip substrate and covered with an insulating layer; determining the location of an opening on the insulating layer, wherein the opening location corresponds to the embedded position of the chip on the embedded chip substrate; using an ultraviolet laser to ablate the opening location according to preset laser parameters to form an initial blind hole at the opening location; and performing a residual removal treatment on the initial blind hole using a plasma device to obtain a target blind hole. As can be seen, the present invention uses an ultraviolet laser to process the initial blind hole at the opening location. The high energy of ultraviolet laser photons can be used to directly destroy molecular bonds, achieve cold ablation, and reduce thermal damage. Furthermore, the residual removal treatment of the initial blind hole using a plasma device can produce a target blind hole with a smooth hole wall. Compared to existing technologies, this method achieves high-precision and high-quality blind hole processing. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments of the present invention. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative labor.

[0017] Figure 1 This is a process flow chart of a blind hole machining method disclosed in one embodiment of the present invention; Figure 2 This is a schematic structural diagram of an embedded chip substrate disclosed in one embodiment of the present invention; Figure 3 This is a partial process flow chart of a blind hole machining method disclosed in one embodiment of the present invention; Figure 4 1 is a schematic structural diagram of a copper-clad substrate disclosed in one embodiment of the present invention; Figure 5 is a schematic structural diagram of a build-up substrate disclosed in one embodiment of the present invention; Figure 6 is a schematic structural diagram of a cavity substrate disclosed in one embodiment of the present invention; Figure 7 is a schematic structural diagram of a chip substrate disclosed in one embodiment of the present invention; Figure 8 1 is a schematic structural diagram of an initial blind via and / or a target blind via on an embedded chip substrate disclosed in one embodiment of the present invention; Figure 9 This is a partial process flow chart of a blind hole machining method disclosed in one embodiment of the present invention; Figure 10 This is a partial process flow chart of a blind hole machining method disclosed in one embodiment of the present invention; Among them, 1a, 1b and 1c are different chips respectively, 2 is the inner core board, 3a and 3b are the first copper layer, 4a and 4b are the second copper layer, 5a and 5b are the first insulating layer, 6a and 6b are the second insulating layer, 7a, 7b and 7c are different cavities respectively, and 8 is the initial blind hole and / or target blind hole. DETAILED DESCRIPTION

[0018] In order to make the technical problems, technical solutions and beneficial effects solved by the present invention more clearly understood, the present invention is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0019] It should be understood that when used in the present specification and the appended claims, the term "comprising" indicates the presence of described features, integers, steps, operations, elements and / or components, but does not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components and / or groups thereof.

[0020] It will also be understood that the term "and / or" used in the present description and appended claims refers to and includes any and all possible combinations of one or more of the associated listed items.

[0021] As used in the present specification and the appended claims, the term "if" may be interpreted as "when" or "upon" or "in response to determining" or "in response to detecting," depending on the context. Similarly, the phrase "if it is determined" or "if [described condition or event] is detected" may be interpreted as meaning "upon determination" or "in response to determining" or "upon detection of [described condition or event]" or "in response to detecting [described condition or event]," depending on the context.

[0022] In addition, in the description of the present specification and the appended claims, the terms "first", "second", "third", etc. are only used to distinguish the descriptions and cannot be understood as indicating or implying relative importance.

[0023] References to "one embodiment" or "some embodiments" in the present specification mean that a particular feature, structure, or characteristic described in connection with that embodiment is included in one or more embodiments of the present invention. Thus, phrases such as "in one embodiment," "in some embodiments," "in other embodiments," and "in yet other embodiments" appearing in various places in this specification do not necessarily refer to the same embodiment, but rather mean "one or more, but not all, embodiments," unless otherwise specifically stated. The terms "including," "comprising," "having," and variations thereof mean "including but not limited to," unless otherwise specifically stated.

[0024] The present invention provides a blind hole processing method and substrate. The method comprises preparing an embedded chip substrate, wherein a chip is embedded in the embedded chip substrate and covered with an insulating layer; determining the location of an opening on the insulating layer, wherein the opening location corresponds to the embedded position of the chip on the embedded chip substrate; using an ultraviolet laser to ablate the opening location according to preset laser parameters to form an initial blind hole at the opening location; and performing a residual removal treatment on the initial blind hole using a plasma device to obtain a target blind hole. As can be seen, the present invention uses an ultraviolet laser to process the initial blind hole at the opening location. The high energy of ultraviolet laser photons can be used to directly destroy molecular bonds, achieve cold ablation, and reduce thermal damage. Furthermore, the residual removal treatment of the initial blind hole using a plasma device can produce a target blind hole with a smooth hole wall. Compared to existing technologies, this method achieves high-precision and high-quality blind hole processing.

[0025] In one embodiment, Figure 1 As shown, the blind hole processing method in this embodiment may include the following processing steps: S101: preparing an embedded chip substrate, wherein a chip is embedded in the embedded chip substrate and an insulating layer covers the chip.

[0026] refer to Figure 2 As shown in the figure, it is a schematic diagram of the structure of the embedded chip substrate in this embodiment, wherein 1a, 1b and 1c are different chips respectively, 2 is the inner core board, 3a and 3b are the first copper layer, 4a and 4b are the second copper layer, 5a and 5b are the first insulating layer, and 6a and 6b are the second insulating layer. Figure 2 The second insulating layer in.

[0027] In one embodiment, Figure 3 As shown, the embedded chip substrate in this embodiment can be prepared by the following steps: S301: preparing a copper-clad substrate based on an inner core board and a first copper foil.

[0028] Among them, the inner core board can be any one of high-frequency substrates such as polytetrafluoroethylene (PTFE), glass fiber reinforced epoxy resin laminate material (FR-4), etc. The first copper foil can be a copper foil with a thickness of 18-35um, and the first copper layer formed by the first copper foil is attached to both sides of the inner core board. It should be noted that when the substrate of the inner core board is different, the preparation method of the copper clad substrate is also different. In addition, the surface of the first copper foil in this embodiment has been chemically etched to form a circuit pattern, and the first copper layer formed by the first copper foil provides mechanical support and basic circuit interconnection for the copper clad substrate. The structure of the copper clad substrate can refer to Figure 4 As shown, 2 is the inner core board, 3a and 3b are the first copper layers.

[0029] For example, taking the inner core board as FR-4, the glass fiber cloth is dewaxed and treated with a coupling agent to enhance the adhesion between the glass fiber cloth and the resin, the glass fiber cloth is impregnated with epoxy resin glue to form a semi-cured sheet, the first copper foil is cleaned and oxidized to improve the adhesion between the first copper foil and the semi-cured sheet, the semi-cured sheet and the first copper foil are bonded according to the process requirements, and then placed in a laminator for pressing to form a copper-clad substrate including the inner core board and the first copper layer.

[0030] S302: Performing a build-up process on the copper-clad substrate based on the build-up material and the second copper foil to obtain a build-up substrate.

[0031] Among them, the build-up layer material can be an epoxy resin insulation film with a thickness of 20-50um, which has the characteristics of high heat resistance and low dielectric constant (DK≈3.5) and is used for insulation and filling; the second copper foil can be an electrolytic copper foil with a thickness of 5-12um.

[0032] In a specific implementation, in this embodiment, the build-up material can be covered on both sides of the copper-clad substrate to form a first insulating layer. After the second copper foil is roughened, it is attached to the outer layer of the first insulating layer to form a second copper layer to obtain a build-up substrate. The structure of the build-up substrate can be referred to Figure 5 As shown, 2 is the inner core board, 3a and 3b are the first copper layer, 4a and 4b are the second copper layer, and 5a and 5b are the first insulating layer.

[0033] S303: Cutting a cavity at a preset cutting position on the build-up substrate using a cavity cutting device to obtain a cavity substrate.

[0034] The cavity cutting equipment can be any one of laser cutting equipment, mechanical cutting equipment, etc., wherein the mechanical cutting equipment includes but is not limited to any one of a multi-blade splitter, a pneumatic splitter and a CNC cutting machine. The structure of the cavity substrate can be as follows Figure 6As shown, 2 is the inner core board, 3a and 3b are the first copper layers, 4a and 4b are the second copper layers, 5a and 5b are the first insulating layers, and 7a, 7b and 7c are different cavities.

[0035] S304: Implanting the chip into the corresponding cavity to obtain a chip substrate.

[0036] The structure of the chip substrate can be as follows: Figure 7 As shown, 1a, 1b and 1c are different chips, 2 is the inner core board, 3a and 3b are the first copper layer, 4a and 4b are the second copper layer, 5a and 5b are the first insulating layer, 6a and 6b are the second insulating layer, 7a, 7b and 7c are different cavities, and chips 1a, 1b and 1c are implanted in the cavities 7a, 7b and 7c respectively.

[0037] S305: Based on the filling material, the chip substrate is further filled and pressed and baked to obtain an embedded chip substrate.

[0038] Specifically, in this embodiment, after the chip substrate is further filled and press-baked with a filler material, a second insulating layer is formed on both sides of the chip substrate to obtain an embedded chip substrate. The filler material and the build-up layer material can be the same or different materials. For example, the filler material and the build-up layer material can both be epoxy resin. However, the thickness of the second insulating layer formed based on the filler material can be different from or the same as the thickness of the first insulating layer, and this is not limited in this embodiment.

[0039] S102: Determine the opening position on the insulation layer.

[0040] The opening position corresponds to the embedding position of the chip on the embedded chip substrate.

[0041] In a specific implementation, in this embodiment, the embedded chip substrate can be fixed on a processing table of a laser processing device. When the embedded chip substrate is fixed, the position of the opening in the insulating layer of the embedded chip substrate is also fixed. The position of the opening in the insulating layer is determined based on the embedded position of the chip in the embedded chip substrate. The opening position is the processing coordinate in the machine coordinates of the laser processing device.

[0042] S103: laser ablation is performed on the opening position by using an ultraviolet laser according to preset laser parameters to form an initial blind hole at the opening position.

[0043] Specifically, the laser parameters in this embodiment may include one or more of laser energy, scanning speed, pulse width, and wavelength. The laser energy may be 1 to 5 J / cm², the scanning speed may be 1 to 5 m / s, the pulse width may be less than or equal to 10 ns, and the wavelength may be 355 nm. Based on the above laser parameters, laser ablation is performed at the hole location to form an initial blind hole at the hole location.

[0044] Furthermore, if the initial blind hole machined at the hole location does not meet the hole opening requirements after a single laser ablation using an ultraviolet laser according to preset laser parameters, the hole location may be laser ablated multiple times using an ultraviolet laser according to preset laser parameters until the initial blind hole machined at the hole location meets the hole opening requirements. There may be one or more hole locations, and the number of correspondingly machined initial blind holes may also be one or more. In this embodiment, there is no limitation on the number of hole locations and initial blind holes.

[0045] S104: performing a residual cleaning process on the initial blind hole by using a plasma device to obtain a target blind hole.

[0046] It is understandable that there may be residual glue residue in the initial blind hole processed by laser ablation, resulting in a higher roughness of the target blind hole wall. Therefore, etching the initial blind hole with a plasma device can reduce the roughness of the target blind hole wall. The roughness of the hole wall after the residue removal treatment can reach 0.5-1um. The initial blind hole after the residue removal treatment is the target blind hole. Figure 8 , which is a schematic structural diagram of the initial blind via and / or target blind via on the embedded chip substrate in this embodiment, wherein 8 represents the initial blind via and / or target blind via.

[0047] Furthermore, the working environment requirements for laser ablation and residue removal in this embodiment may be: the number of particles greater than or equal to 0.5 μm per cubic foot of air is between 1,000 and 10,000, the ambient temperature is 20-25°C, and the ambient humidity is 40% to 60%. The particle types include any one or more of resin particles, metal particles, and glass fiber particles, and the number of particles may be the number of any one type of particles or the total number of multiple types of particles, which is not limited in this embodiment. It should be noted that the above working environment requirements are merely illustrative, and technical solutions formed by appropriate adjustments to them are also within the scope of protection of the present invention.

[0048] In summary, the present embodiment provides a blind hole processing method, which comprises preparing an embedded chip substrate, wherein a chip is embedded in the embedded chip substrate and covered with an insulating layer; determining a hole position on the insulating layer, wherein the hole position corresponds to the embedded position of the chip on the embedded chip substrate; performing laser ablation at the hole position using an ultraviolet laser according to preset laser parameters to process an initial blind hole at the hole position; and performing a residual removal treatment on the initial blind hole using a plasma device to obtain a target blind hole. It can be seen that the present embodiment uses an ultraviolet laser to process the initial blind hole at the hole position. The high energy of ultraviolet laser photons can directly destroy molecular bonds, achieve cold ablation, and reduce thermal damage. Simultaneously, the residual removal treatment of the initial blind hole by the plasma device can obtain a target blind hole with a smooth hole wall. Compared with the prior art, the method of the present embodiment can achieve blind hole processing with a hole diameter of less than or equal to 20 μm and a pitch spacing of less than or equal to 5 μm, significantly improving the processing accuracy and quality of the blind holes.

[0049] In one embodiment, Figure 9 As shown, the laser parameters include a first parameter and a second parameter. The processing step S103 in the above embodiment may include the following processing steps: S901: Using an ultraviolet laser, according to a first parameter, a first number of first laser ablations are performed on the opening position to form a guide hole at the opening position.

[0050] S902: Using an ultraviolet laser, according to a second parameter, a second number of second laser ablation is performed on the opening position to process the guide hole into an initial blind hole.

[0051] In one embodiment, the first parameters in this embodiment may include a first laser energy, a first scanning speed, and a first pulse width, wherein the first laser energy is less than 1 J / cm², the first scanning speed is 1 to 5 m / s, and the first pulse width is less than or equal to 10 ns. The second parameters in this embodiment may include a second laser energy, a second scanning speed, and a second pulse width, wherein the second laser energy is 1 to 5 J / cm², the second scanning speed is 1 to 5 m / s, and the second pulse width is less than or equal to 10 ns. It can be seen that the first laser energy of the first laser ablation is less than the second laser energy of the second laser ablation. It can be understood that the first laser ablation is pre-ablation, while the second laser ablation is main ablation. The purpose of pre-ablation is to remove impurities such as oxide layers, oil stains, and particles from the surface of the opening using low-energy laser pulses, ensuring that the laser energy in the main ablation phase directly acts on pure material to prevent contaminants from affecting processing quality. The purpose of main ablation is to use high-energy laser pulses to quickly remove material and achieve high-efficiency processing. Furthermore, the high scanning speed (1 to 5 m / s) can ensure that each pulse area has no overlap, reducing heat accumulation.

[0052] In a specific implementation, the first number in this embodiment is usually one, and the oxide layer, oil stains, particles and other impurities on the surface of the opening position are removed through one pre-ablation to form a guide hole. If the guide hole cannot be formed by one pre-ablation, the number of pre-ablations can be appropriately adjusted, that is, the first number is adjusted, and the second number is determined according to the thickness of the insulating layer.

[0053] For example, taking a 30um insulating layer as an example, the pre-ablation depth is 3um. Then, when the main ablation depth is 5um, the main ablation times are 5 times, and the total ablation depth is 28um. The purpose of reserving 2um is to ensure physical isolation between the bottom of the blind hole and the chip below, avoiding chip damage due to processing errors or material unevenness, which is beneficial to improving the yield rate of the packaging substrate.

[0054] Furthermore, the parameter differences of the UV laser used in this embodiment compared with the conventional CO2 laser and the long pulse UV laser can be shown in Table 1: As can be seen, due to the significantly longer infrared wavelength (10.6 μm), conventional CO2 lasers are more easily absorbed by the insulating layer (ABF), resulting in severe thermal diffusion within the insulating layer and an excessively large heat-affected zone, making it impossible to achieve small aperture requirements. Conventional long-pulse UV lasers, due to their slow scanning speed (0.5–1 m / s), result in prolonged energy deposition. Heat accumulation can easily lead to resin carbonization, blackening of the hole walls, or hole enlargement. In contrast, the UV laser used in this embodiment boasts high photon energy (3.5 eV), which directly breaks the molecular bonds (CC / CH) in the insulating layer, achieving cold ablation and minimizing thermal damage. Furthermore, this solution utilizes short pulse widths (10 ns) and high energy density to achieve instantaneous vaporization, resulting in a low heat diffusion rate. High scanning speeds (1–5 m / s) ensure zero overlap between pulses, minimizing heat accumulation.

[0055] In summary, in this embodiment, a short-pulse (pulse width less than or equal to 10ns) ultraviolet laser is used to process the initial blind hole at the opening position. Compared with conventional CO2 lasers and long-pulse ultraviolet lasers (pulse width 10-100ns), the long pulse energy deposition time is avoided, which leads to heat accumulation and resin carbonization, blackening of the hole wall or hole expansion. At the same time, the short-pulse ultraviolet laser combined with high energy density (1-5J / cm²) can achieve instantaneous vaporization of the insulating layer, and the heat diffusivity is low. Moreover, in this embodiment, pre-ablation and multiple main ablations are combined to achieve laser multi-step layered ablation, increase the cooling time, reduce the heat-affected zone, and thus reduce the impact of heat on the insulating layer, which can effectively avoid the problem of insulating layer delamination caused by thermal damage.

[0056] In one embodiment, Figure 10As shown, the residue removal process in this embodiment includes etching and passivation. Step S104 in the above embodiment can be implemented by the following steps: S1001: Using plasma equipment, the initial blind hole is alternately etched and passivated to obtain a target blind hole.

[0057] In a specific implementation, in this embodiment, the initial blind hole can be first etched to remove the residual slag in the initial blind hole and refine the hole shape. The initial blind hole is then passivated to form a periodic protective layer in the initial blind hole. The initial blind hole is then etched again, and so on, to achieve alternating etching and passivation of the initial blind hole, and finally obtain the target blind hole. It should be understood that in this embodiment, a thick protective layer is formed on the wall of the blind hole through the passivation treatment. The plasma equipment can usually only perform longitudinal etching on the blind hole, that is, etching along the depth direction of the blind hole. The protective layer can prevent the plasma equipment from etching the wall of the blind hole. Among them, the passivation gas used for the passivation treatment in this embodiment includes perfluorocyclobutane; the etching gas used for the etching treatment includes a mixed gas formed by carbon tetrafluoride and oxygen, and the volume ratio of carbon tetrafluoride to oxygen is 4:1. It should be noted that the above-mentioned passivation gas, etching gas and the ratio of etching gas are merely an exemplary description in this embodiment, and do not constitute a specific limitation on the ratio of passivation gas, etching gas and etching gas. The technical solution formed by replacing or adjusting the ratio of passivation gas, etching gas and etching gas is also within the scope of protection of the present invention.

[0058] In one embodiment, the thickness of the first copper foil is 18-35 μm, the thickness of the second copper foil is 5-12 μm, the thickness of the build-up material is 20-50 μm, the material type of the build-up material is epoxy resin insulating film, and the dielectric constant of the build-up material is DK ≈ 3.5. It should be noted that the thickness of the first copper foil, the thickness of the second copper foil, the thickness of the build-up material, the material type of the build-up material, and the dielectric constant of the build-up material are merely exemplary of this embodiment, and the resulting technical solution, after adaptive adjustments, falls within the scope of protection of the present invention.

[0059] In one embodiment, the plasma parameters of the plasma apparatus in this embodiment include: a power of 200W and a chamber pressure of 5-20mTorr. It should be noted that the above plasma parameters are merely exemplary of this embodiment, and the resulting technical solution after adaptive adjustment of the plasma parameters is also within the scope of protection of the present invention.

[0060] The embodiments described above are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. These modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the various embodiments of the present invention, and should all be included in the scope of protection of the present invention.

Claims

1. A blind hole processing method, characterized in that: include: A chip-embedded substrate is prepared, wherein a chip is embedded in the chip-embedded substrate and an insulating layer is covered on the chip; Determining a position of an opening on the insulating layer, wherein the position of the opening corresponds to a position where the chip is embedded in the embedded chip substrate; Using an ultraviolet laser, laser ablation is performed on the opening position according to preset laser parameters to form an initial blind hole at the opening position; The initial blind hole is subjected to a residual cleaning process by a plasma device to obtain a target blind hole.

2. The blind hole processing method according to claim 1, characterized in that: The laser parameters include a first parameter and a second parameter; The laser ablation of the opening position is performed by ultraviolet laser according to preset laser parameters to form an initial blind hole at the opening position, including: Using the ultraviolet laser, according to the first parameters, a first number of first laser ablations are performed on the opening position to form a guide hole at the opening position; The second laser ablation is performed a second time on the opening position by the ultraviolet laser according to the second parameter, so as to process the guide hole into an initial blind hole.

3. The blind hole processing method according to claim 2, characterized in that: The first parameters include a first laser energy, a first scanning speed, and a first pulse width, the first laser energy is less than 1 J / cm², the first scanning speed is 1 to 5 m / s, and the first pulse width is less than or equal to 10 ns; the second parameters include a second laser energy, a second scanning speed, and a second pulse width, the second laser energy is 1 to 5 J / cm², the second scanning speed is 1 to 5 m / s, and the second pulse width is less than or equal to 10 ns.

4. The blind hole processing method according to claim 1, characterized in that: The residue removal process includes etching and passivation; The method of performing a residual cleaning process on the initial blind hole by a plasma device to obtain a target blind hole comprises: The target blind hole is obtained by alternately performing etching treatment and passivation treatment on the initial blind hole using an etching gas and a passivation gas through a plasma device.

5. The blind hole processing method according to claim 4, characterized in that: The passivation gas includes perfluorocyclobutane; the etching gas includes a mixed gas formed by carbon tetrafluoride and oxygen, and the volume ratio of the carbon tetrafluoride to the oxygen is 4:

1.

6. The blind hole processing method according to claim 1, characterized in that: The method for preparing an embedded chip substrate comprises: A copper-clad substrate is prepared based on the inner core board and the first copper foil; Performing a build-up process on the copper-clad substrate based on a build-up material and a second copper foil to obtain a build-up substrate; Using a cavity cutting device, cutting a cavity at a preset cutting position on the build-up substrate to obtain a cavity substrate; implanting a chip into the corresponding cavity to obtain a chip substrate; Based on the filling material, the chip substrate is further filled and pressed and baked to obtain the embedded chip substrate.

7. The blind hole processing method according to claim 6, characterized in that: The thickness of the first copper foil is 18-35um, the thickness of the second copper foil is 5-12um, the thickness of the build-up material is 20-50um, the material type of the build-up material is epoxy resin insulating film, and the dielectric constant of the build-up material is DK≈3.

5.

8. The blind hole processing method according to any one of claims 1 to 7, characterized in that: The working environment of the laser ablation and / or the plasma etching includes: cleanliness: the number of particles larger than or equal to 0.5 μm per cubic foot of air is between 1,000 and 10,000, ambient temperature: 20-25° C., and ambient humidity: 40% to 60%.

9. The blind hole processing method according to any one of claims 1 to 7, characterized in that: The plasma parameters of the plasma equipment include: power 200W, chamber pressure 5-20mTorr.

10. A substrate, characterized in that: The substrate includes a target blind hole, and the target blind hole is processed based on the blind hole processing method according to any one of claims 1 to 9.

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