Multi-size electronic carrier sheet and via processing method

Abstract

The application provides a multi-size electronic carrier wafer via processing method, comprising the following steps: providing a first carrier wafer Core layer, synchronously processing a plurality of first vias and at least two first target points on the small-size rigid substrate, the first target points being distributed at both ends of the substrate; embedding the first carrier wafer Core layer into a hollow frame-shaped second carrier wafer Core layer to form a composite carrier wafer structure, wherein the inner diameter of the second carrier wafer matches the outer edge of the first carrier wafer; pressing and bonding a thermosetting dielectric material on both sides of the composite carrier wafer to fill the first vias with the dielectric material; identifying the first target points by an X-ray device, drilling second target points at a distance of 5-50 mm from the first target points in the second carrier wafer region; and taking the second target points as alignment reference points to drill second vias with a smaller diameter than the first vias in the projection range of the first vias. The method has the advantages of improving the via alignment accuracy of the composite carrier wafer structure, reducing the risk of thermal compression deformation, and improving product yield.

Description

Technical Field

[0001] This application relates to the field of electronic packaging material processing technology, and more specifically, to a multi-size electronic carrier sheet and a through-hole processing method. Background Technology

[0002] With the rapid development of artificial intelligence technology, the performance requirements of packaging materials for large-size chips are increasing, leading to a greater demand for the size and number of layers of electronic carrier wafers. However, large-size multilayer structures result in a significant increase in processing energy consumption, placing more stringent demands on the aperture accuracy, hole shape consistency, and electroplating filling of the core layer. In traditional processes, large-size through-holes are difficult to completely fill with electroplating solution, easily generating internal cavity defects that seriously affect product reliability. Existing solutions typically employ a secondary drilling process, where smaller through-holes are drilled again within the initially processed large through-holes to achieve effective electroplating filling. However, this process has significant technical bottlenecks: due to the cumulative tolerances generated in lamination, hot pressing, and other processes on large-size substrates, it is difficult to accurately align the initial through-hole position during secondary drilling, causing drilling offsets or even penetration through adjacent circuit layers. Especially in composite carrier wafer structures, when small-size core layers are embedded in standard-size frames, the difference in thermal expansion coefficients of different materials further amplifies the alignment error. Currently, the mechanical positioning or optical alignment methods commonly used in the industry cannot effectively solve the target point transfer accuracy problem across size structures, making it difficult to achieve a product yield exceeding 60%. In addition, dielectric materials are prone to uneven shrinkage during high-temperature flow filling, which exacerbates the deformation risk at the through-hole location.

[0003] To address the aforementioned issues, existing technologies urgently need improvement. Summary of the Invention

[0004] The purpose of this application is to provide a multi-size electronic carrier sheet and a through-hole processing method, which has the advantages of improving the alignment accuracy of through holes in composite carrier sheet structures, reducing the risk of hot-pressing deformation, and improving product yield.

[0005] This application provides a method for processing through-holes in multi-size electronic carrier sheets with high alignment accuracy. The technical solution is as follows: A method for processing through-holes in multi-size electronic carrier sheets with high alignment accuracy includes the following steps: (a) providing a first carrier sheet Core layer, and simultaneously processing a plurality of first through-holes and at least two first target points on the small-size rigid substrate, the first target points being distributed at both ends of the substrate; (b) embedding the first carrier sheet Core layer into a hollow frame-shaped second carrier sheet Core layer to form a composite carrier sheet structure, wherein the inner diameter of the second carrier sheet matches the outer edge of the first carrier sheet; (c) pressing thermosetting dielectric material onto both sides of the composite carrier sheet, heating it to above the glass transition temperature (Tg) to allow the dielectric material to flow and fill the first through-holes; (d) identifying the first target points using an X-ray device, and drilling a second target point 5-50 mm away from the first target point in the area of ​​the second carrier sheet; (e) using the second target point as an alignment reference, drilling a second through-hole with a diameter smaller than the first through-hole within the projection range of the first through-hole.

[0006] Furthermore, this application also proposes that the ratio of the diameter of the first through hole to the diameter of the second through hole is 100:5 to 100:90.

[0007] Furthermore, this application also proposes that step (e) includes drilling a plurality of non-overlapping second through holes within a single first through hole.

[0008] Furthermore, this application also proposes that the processing of the first target point and the first through hole are completed simultaneously using laser-induced etching.

[0009] Furthermore, this application also proposes that the dielectric material be ABF or Prepreg resin.

[0010] Furthermore, this application also proposes that the second target point may be located in the Core layer of the first carrier chip.

[0011] Furthermore, this application also proposes a high-precision multi-size through-hole electronic transport sheet, comprising: a composite transport sheet Core layer, consisting of an embedded small-sized first transport sheet Core layer and a peripheral hollow second transport sheet Core layer; the first transport sheet Core layer having at least two first target points and a plurality of first through holes; a cured dielectric material layer filling the first through holes; a second target point disposed on the second transport sheet Core layer, the position of which is generated based on the first target point by X-ray positioning, and the distance between the second target point and the nearest first target point is 5-50mm; and a second through hole penetrating the dielectric material layer and the first through holes, the diameter of which is smaller than that of the first through holes and is completely located within the projection range of the first through holes.

[0012] Furthermore, this application also proposes that the ratio of the diameter of the first through hole 2 to the diameter of the second through hole 6 is 100:5 to 100:90.

[0013] Furthermore, this application also proposes that a single first through hole contains at least two non-overlapping second through holes.

[0014] Furthermore, this application also proposes that the dielectric material layer is ABF resin, and its filling depth covers the entire depth of the first through hole.

[0015] As can be seen from the above, the method for processing through holes of multi-size electronic carrier sheets with high alignment accuracy and the high-precision multi-size through-hole electronic carrier sheet provided in this application, through composite carrier sheet structure design and X-ray assisted target transfer technology, accurately generates a secondary drilling reference after hot-pressing and filling dielectric material, effectively eliminating the cumulative tolerance caused by material thermal expansion differences, and ensuring that small-size through holes are completely within the initial through-hole projection range. It has the advantages of improving the alignment accuracy of through holes in composite carrier sheet structure, reducing the risk of hot-pressing deformation, and improving product yield. Attached Figure Description

[0016] Figure 1-5 This is a schematic diagram of a through-hole processing method for a multi-size electronic carrier chip provided in this application.

[0017] Figure 6 for Figure 5 Enlarged view of region A in the middle;

[0018] Figure 7 This application provides a schematic diagram showing that the second through hole is a multi-through hole;

[0019] Figure 8 for Figure 7 Enlarged view of region B in the middle;

[0020] Figure 9 A schematic diagram illustrating the formation of a second target point in the Core layer of the 25% size first carrier wafer provided in this application;

[0021] Figure 10 A schematic diagram showing the formation of a second target point in the Core layer of the first carrier chip with the unit size provided in this application;

[0022] Figure 11 This is a schematic diagram illustrating the positional offset of the second through-hole in an existing electronic carrier chip.

[0023] Figure 12 This is a schematic diagram showing the positional offset of the second through hole in the electronic carrier plate of the present invention. Detailed Implementation

[0024] The technical solutions of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of the embodiments. The components of this application described and shown in the accompanying drawings can generally be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of this application provided in the accompanying drawings is not intended to limit the scope of the claimed application, but merely represents selected embodiments of this application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without inventive effort are within the scope of protection of this application. It should be noted that similar reference numerals and letters in the following drawings indicate similar items; therefore, once an item is defined in one drawing, it does not need to be further defined and explained in subsequent drawings. Furthermore, in the description of this application, the terms "first," "second," etc., are used only to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0025] In existing technologies, the rapid development of artificial intelligence has driven the growth in demand for large-size chip packaging. The increase in the size and number of layers of electronic carrier wafers has placed higher requirements on the precision of through-hole processing. Traditional secondary through-hole processing methods rely on layer-by-layer alignment references. As the number of processing steps increases, cumulative tolerances occur, causing the final through-hole position to deviate beyond the allowable range. When the size of the carrier wafer expands to standard industrial specifications, substrate deformation and equipment positioning errors further exacerbate this problem, resulting in a significant increase in the through-hole alignment failure rate.

[0026] However, existing technologies cannot effectively eliminate the cumulative errors generated by multi-process machining. Establishing a stable reference point in the initial machining stage can prevent the introduction of new error sources in subsequent processes. Simultaneously, a composite structure design can maintain machining accuracy on small-sized substrates, which can then be extended to standard sizes through physical matching. Based on this, a method is proposed to simultaneously machine through-holes and target points in the core layer to form an initial reference point, utilize X-ray penetration characteristics to inherit the initial positioning information, and finally perform secondary drilling within a defined area.

[0027] Therefore, this application proposes a processing method including the following steps:

[0028] like Figure 1 A first carrier core layer 100 is provided, and a plurality of first through holes 2 and at least two first target points 3 are simultaneously processed on the small-sized rigid substrate. The first target points 3 are distributed at both ends of the substrate.

[0029] The first carrier core layer 100 refers to the small-sized substrate that supports the initial processing structure. Specifically, it can be implemented using a glass fiber reinforced epoxy resin substrate, whose rigidity ensures the processing accuracy of the initial through-holes and target points. The first target point 3 refers to the physical marker used for spatial positioning. Specifically, it can be implemented using metal pits formed by laser etching, which are distributed at both ends of the substrate to construct a stable planar coordinate system.

[0030] This application further proposes that the processing of the first target point 3 and the first through hole 2 are completed simultaneously using laser-induced etching.

[0031] Laser-induced etching refers to a processing method that uses a high-energy laser beam to induce a chemical reaction on the surface of a substrate to form a predetermined shape. Specifically, it can be achieved using an ultraviolet laser in conjunction with a photosensitive etching solution. This technology has micron-level processing precision. Simultaneous completion means that the first target point 3 and the first through-hole 2 are continuously completed in the same processing step using the same equipment. Specifically, the sequential processing of the two structures can be achieved by programming and controlling the laser path, ensuring a consistent processing benchmark.

[0032] Specifically, during laser-induced etching, the control system drives the laser head to move according to preset coordinate data. First, it scans at both ends of the substrate to form the first target points, and then scans the area between the target points to form the first through-hole. Since both structures are completed within the same equipment positioning cycle, mechanical errors caused by repeated positioning during step-by-step processing are avoided. The substrate remains fixed to the vacuum adsorption platform throughout the processing, eliminating displacement deviations caused by multiple clamping operations. The resulting target points and through-holes have a precise relative positional relationship, establishing a reliable spatial reference for the subsequent generation of the second target point.

[0033] This solution eliminates the cumulative tolerances caused by step-by-step operations through single-process synchronous processing, improving the positional accuracy of the target point and the through hole to the inherent accuracy level of the laser processing equipment. It also effectively solves the reference offset problem caused by step-by-step processing, ensuring the positional accuracy of the second target point generated based on the first target point. This ensures that the second through hole can accurately fall within the projection range of the first through hole, avoiding through hole overlap or offset defects caused by alignment deviation.

[0034] like Figure 2 The first carrier core layer 100 is embedded in the hollow frame-shaped second carrier core layer 400 to form a composite carrier structure, wherein the inner diameter of the second carrier matches the outer edge of the first carrier, and the outer diameter is a standard size of 510×515mm.

[0035] The composite carrier structure refers to a composite consisting of an embedded core layer and an outer frame. Specifically, it can be realized by machining a hollow frame using a CNC milling machine, and the inner diameter matching design ensures that there is no displacement gap between the components.

[0036] The composite carrier core layer refers to the combined structure in which a small first carrier is embedded in a hollow frame-shaped second carrier. This can be achieved through mechanical fitting or bonding processes. By coordinating the processing of small and large areas, different precision requirements can be met.

[0037] like Figure 3 Thermosetting dielectric material is pressed onto both sides of the composite carrier sheet and heated to above the glass transition temperature to allow the dielectric material to flow and fill the first through hole 2.

[0038] Thermosetting dielectric materials are insulating materials with thermosetting properties. Specifically, they can be formed by heating and curing ABF resin or Prepreg resin. During the heating and pressurization process, they can completely fill the internal space of the through hole, provide physical support for the second through hole, and maintain the stability of the through hole structure.

[0039] ABF resin refers to a thin-film polymer material with thermosetting properties and low viscosity flow characteristics. Specifically, it can be achieved using polyimide materials with added epoxy resin systems. When heated above the glass transition temperature, it becomes fluid, allowing it to penetrate into the pores and form a void-free filling layer. Prepreg resin refers to a semi-cured sheet composite material containing pre-impregnated glass fibers. Specifically, it can be achieved by impregnating glass fiber cloth with epoxy resin followed by partial curing. After curing, it forms a medium layer that combines filling and structural support. Both types of materials have coefficients of thermal expansion that match those of the rigid substrate, maintaining consistent deformation between the filling layer and the substrate during temperature changes.

[0040] Specifically, during the lamination process of the composite carrier sheet, the ABF resin softens upon heating and flows into the first through-hole through capillary action. Its low viscosity ensures that the filling process covers the hole walls and bottom area, eliminating residual air bubbles within the hole. The glass fibers in the Prepreg resin form a mesh support structure after curing, enhancing the deformation resistance of the filler layer. The improved surface smoothness of the dielectric layer formed by the curing of these two materials provides a rigid reference surface for the subsequent machining of the second through-hole, preventing positioning misalignment caused by the shrinkage or expansion of the dielectric layer during drilling.

[0041] The ABF resin used in this solution achieves controllable flow through optimized molecular chain structure, while Prepreg resin enhances the rigidity of the filler layer through fiber reinforcement. Both can maintain the dimensional stability of the dielectric layer during secondary drilling, overcoming the alignment drift caused by thermal deformation of traditional materials. This achieves complete filling of the through hole to eliminate reliability risks, while forming a dielectric layer substrate with stable mechanical properties. This ensures that the drilling equipment can accurately position itself based on the surface of the cured dielectric layer during the second through hole processing, avoiding the problem of cumulative tolerance exceeding the standard due to deformation of the filler material.

[0042] like Figure 4-6The first target point 3 is identified by X-ray equipment, and the second target point 5 is drilled at a set distance from the first target point 3 in the second carrier film area; the second target point 5 is used as the alignment reference, and the second through hole 6 with a diameter smaller than the first through hole 2 is drilled within the projection range of the first through hole 2.

[0043] X-ray equipment identification refers to the use of penetrating rays to detect target coordinates, which can be achieved using a digital imaging system to ensure accurate reading of the initial reference position even under composite structures. The second target point 5 refers to a secondary processing reference point, which can be achieved by mechanically drilling to create a through hole. Maintaining a set distance from the first target point 3 avoids signal interference.

[0044] The second target point 5 refers to the secondary positioning mark generated based on the first target point 3 within the second carrier area. Specifically, it can be drilled by offsetting a set distance after identifying the first target point 3 with an X-ray device. Non-contact positioning avoids mechanical alignment errors and ensures the processing accuracy of large-size areas.

[0045] The second through hole 6 refers to a through hole that is completely within the projection range of the first through hole 2 and has a smaller diameter. Specifically, it can be achieved by laser drilling or mechanical drilling. Through the structural design of a large hole with a small hole, the first through hole 2 is used as a position tolerance zone to eliminate the risk of secondary drilling deviation.

[0046] This application further proposes that the ratio of the diameter of the first through hole 2 to the diameter of the second through hole 6 is 100:5 ~ 100:90.

[0047] The first through-hole diameter refers to the diameter of the through-hole initially formed on the substrate, which can be achieved using laser-induced etching or mechanical drilling. This size provides a reference space for subsequent dielectric material filling and secondary processing. The second through-hole diameter refers to the diameter of the through-hole formed after dielectric material filling and secondary processing, which can be achieved using laser drilling or chemical etching. This size must meet the minimum hole diameter requirements of the electroplating filling process.

[0048] Specifically, after forming a relatively large first through-hole 2 on the substrate, a flat surface is formed by filling it with a thermosetting dielectric material. When secondary drilling is performed, since the size of the second through-hole 6 is significantly smaller than that of the first through-hole 2, its processing position can be completely within the projection coverage area of ​​the first through-hole. This size difference design limits the positioning deviation of the secondary drilling to within the boundary of the first through-hole. Even if there is a positional offset of the processing equipment, it can still ensure that the second through-hole and the first through-hole form a nested structure, avoiding hole wall damage caused by offset exceeding the boundary.

[0049] Existing technologies require precise alignment with the original through-hole center during secondary drilling, placing extremely high demands on equipment accuracy. This solution, however, constructs a nested structure with two levels of hole diameters, transforming the positioning accuracy requirement into a containment relationship between hole diameters. This ensures the integrity of the through-hole structure within allowable deviations, effectively resolving the contradiction between the difficulty of electroplating and filling large through-holes and the misalignment during secondary drilling. By setting the dimensional ratio between the two levels of through-holes, it ensures that the through-hole formed in the initial processing has sufficient space to accommodate dielectric material filling, while also ensuring that the smaller holes formed in the secondary processing maintain structural effectiveness even with positional deviations. This improves product yield and reduces equipment accuracy requirements.

[0050] like Figure 7-8 This application further proposes drilling multiple non-overlapping second through holes 6 within a single first through hole.

[0051] In this context, a single first through hole refers to a pre-processed through-hole structure with a fixed diameter and position, which can be achieved using laser etching or mechanical drilling processes. Its spatial range constitutes the physical constraint boundary for secondary drilling. Non-overlapping second through holes refer to multiple independent hole structures formed within the projection range of the same first through hole. This can be achieved using a high-precision CNC drilling machine in conjunction with a vision positioning system, with the edge spacing of each hole maintaining a preset safe distance.

[0052] Specifically, after machining the first through hole, the inner wall contour of the through hole is used as a positioning reference, and multiple second through holes are planned within the internal space using preset coordinate offsets. Since the first through hole has a fixed boundary, the planning of the second through hole positions only needs to consider the hole spacing parameter, without relying on external alignment marks. During machining, the drill bit's movement trajectory is restricted to the projection range of the first through hole, so even if there are equipment positioning errors, the second through holes can still remain completely within the preset area. The non-overlapping layout ensures that adjacent hole walls do not contact each other by setting a minimum spacing threshold, thereby maintaining the independence and integrity of the hole structure.

[0053] This solution confines the second through-hole within the already formed first through-hole, using physical boundary constraints to offset positioning errors. Simultaneously, it employs an in-hole autonomous arrangement strategy to eliminate the risk of multi-hole interference and effectively avoids cumulative errors caused by repeated equipment positioning during secondary drilling, ensuring that multiple small-sized through-holes are precisely distributed within the predetermined area. The non-overlapping design between holes eliminates stress concentration caused by hole wall contact, guaranteeing the mechanical stability of the carrier structure. This solution achieves reliable fabrication of a high-density micro-hole array without requiring additional alignment steps.

[0054] This application further proposes a technical solution that allows the second target to be directly set on the Core layer of the first carrier chip.

[0055] The second target point refers to a physical marker used to establish a secondary drilling reference. It can be formed on the surface of the first carrier core layer using laser etching or mechanical stamping. Its position coordinates are spatially correlated and calibrated with the first target point using X-ray equipment. The first carrier core layer is a small-sized rigid substrate embedded within the composite carrier structure. Its processing accuracy directly affects the stability of the through-hole positioning reference. By directly setting the second target point in this layer, the high-precision characteristics of the original processing coordinate system can be inherited.

[0056] Specifically, when the second carrier core layer in the composite carrier structure deforms due to the hot-pressing process, the reference offset caused by the displacement of the hollow frame structure can be eliminated by directly setting a second target point on the first carrier core layer. Since the first carrier core layer and the first through hole have established a precise geometric relationship during the synchronous processing stage, when secondary drilling is performed based on the target point of this layer, the position of the second through hole can be directly mapped to the original projection range of the first through hole, without relying on the indirect positioning of the external structure.

[0057] In some specific implementations, the second target point can be distributed in the edge region of the first carrier chip Core layer to form a complementary positioning network with the first target point; or an auxiliary target point can be added in the central region of the first carrier chip Core layer to improve positioning reliability through multi-reference point redundancy verification.

[0058] In specific embodiments, such as Figure 9-10 The second target point is formed relative to the relative position of the 25% size first carrier core layer and the unit size first carrier core layer, and is used as the alignment target point for forming the second via.

[0059] This solution breaks through the spatial limitations of target point setting and directly utilizes the original processing precision of the inner layer structure. It shortens the positioning reference transfer path to a single-layer structure, significantly reducing the impact of composite carrier plate deformation on secondary drilling. It also effectively solves the alignment deviation problem caused by interlayer displacement of the composite structure, enabling the drilling position of the second through hole to accurately match the projection range of the first through hole. This avoids hole wall damage or hole position overlap defects caused by reference offset, ensuring the integrity of electroplating filling in the high-density interconnect structure.

[0060] In summary, during the initial processing stage, through-holes and target points are simultaneously formed on the small-sized substrate, establishing an initial spatial coordinate system. After the substrate is embedded into a standard-sized frame, a hot-pressing process is used to completely fill the initial through-holes with dielectric material, forming a flat processing surface. Before secondary processing, X-rays are used to penetrate the multi-layer structure to accurately locate the coordinates of the initial target points, thereby generating secondary reference points within the effective range. During final drilling, the secondary reference points serve as the positioning origin, and combined with projection range limitations, ensure that the secondary through-holes are completely located within the area covered by the initial through-holes. In this process, the simultaneous processing of the initial reference points eliminates coordinate transformation errors between processes, the composite structure design avoids the impact of substrate deformation on accuracy, and the dielectric material filling provides a flat reference surface for subsequent processing.

[0061] In existing technologies, each process requires the establishment of a new reference point, leading to the accumulation of errors layer by layer. This solution inherits the initial reference information, transforming multi-process positioning into a single coordinate mapping, effectively eliminating error superposition. Existing technologies are susceptible to positioning accuracy issues caused by substrate warping during large-size processing, while composite structures utilize small-sized substrates to support key features, avoiding the deformation problems associated with large-area processing.

[0062] Through the above technical solution, this application achieves precise transfer of the secondary through-hole machining reference, controlling the positioning error within the initial through-hole projection range. Utilizing the spatial correlation between the initial target point and the secondary target point, the coordinate mapping problem in multi-layer structures is solved. The composite carrier sheet structure balances the machining accuracy of small sizes with the packaging requirements of large sizes, and the thermosetting material filling ensures the physical stability of the through-hole structure. Ultimately, micron-level alignment accuracy of through-holes is achieved on standard industrial-sized carrier sheets, significantly reducing the machining scrap rate caused by misalignment.

[0063] In the prior art, a first target point is first formed by laser ablation. Laser melting is used to melt the dielectric material on the layer-addition side of the dielectric material in the pre-target point area, exposing a region of the first target point in the first carrier core layer. This region serves as the alignment target for subsequent drilling. It should be noted that this melted area is larger than the diameter of the first target point, forming a second target point. In this process, the second target point can be formed by any method, such as drilling or laser processing. Taking machine drilling as an example, the drilling machine uses the formed first target point as the alignment target to process the second target point in the core layer area of ​​the second carrier. This second target point will be used as the alignment target for subsequent drilling. The composite carrier with the completed second target point is transferred to the drilling machine, and the second target point formed in Step 5 is used as the alignment and fixing hole for the drilling machine. It should be noted that the relative distance (D1) between the first and second target points is approximately half the length of the entire carrier.

[0064] A second through hole is formed. The drilling machine uses the second target point formed in Step 5 as the alignment and fixing hole;

[0065] In existing technologies, drilling a second through-hole within the through-hole area of ​​the first carrier wafer results in significant cumulative tolerances, including the machining position tolerance of the through-hole in the core layer of the first carrier wafer, the positional tolerance between the first target point and the second target point, and the positional tolerance between the second target point and the second through-hole. This series of cumulative tolerances leads to a risk of misalignment in the formed second through-hole, causing yield loss or even scrapping of the composite carrier wafer's core layer. The smaller the size of the first carrier wafer's core layer and the diameters of the first and second through-holes, the more severe the positional misalignment of the second through-hole caused by cumulative tolerances will be.

[0066] like Figure 11-12 The existing electronic carrier chip has a second through-hole position deviation defect rate of ≥60%; the second through-hole position deviation CPk is 0.15.

[0067] In the present invention, the defect rate of the second through hole positional deviation of the improved electronic carrier sheet is ≤1%, and the positional deviation CPk of the second through hole is 3.8; in a better case, the defect rate of deviation is ≤0.1%, and the positional deviation CPk of the second through hole is 8.7.

[0068] This application further proposes a high-precision multi-size through-hole electronic transport sheet, including a composite transport sheet Core layer, which is composed of an embedded small-sized first transport sheet Core layer and a hollow outer second transport sheet Core layer; the first transport sheet Core layer is provided with at least two first target points and a number of first through holes; a solidified dielectric material layer is filled in the first through holes; a second target point is provided on the second transport sheet Core layer, the position of which is generated based on the first target point by X-ray positioning, and the distance between the second target point and the nearest first target point is 5-50mm; a second through hole penetrates the dielectric material layer and the first through holes, the diameter of which is smaller than that of the first through holes and is completely located within the projection range of the first through holes.

[0069] The composite carrier core layer refers to the combined structure in which a small first carrier layer is embedded within a hollow frame-like second carrier layer. This can be achieved using mechanical fitting or bonding processes. By coordinating the processing of small and large areas, different precision requirements can be met. The first target point refers to the positioning marks set at both ends of the first carrier layer. These marks can be formed using laser etching or chemical etching and serve as an initial positioning reference for subsequent processing steps.

[0070] The second target point refers to a secondary positioning mark generated based on the first target point within the second carrier area. Specifically, it can be drilled by offsetting a set distance after identifying the first target point using X-ray equipment. This non-contact positioning avoids mechanical alignment errors and ensures machining accuracy in large areas. The cured dielectric material layer refers to a thermosetting resin material filled within the first through-hole. Specifically, it can be formed by heating and curing ABF resin or Prepreg resin, providing physical support for the second through-hole and maintaining the stability of the through-hole structure. The second through-hole refers to a through-hole with a smaller diameter that is entirely within the projection range of the first through-hole. It can be achieved using laser drilling or mechanical drilling. Through a structure design of a large hole surrounding a smaller hole, the first through-hole serves as a positional tolerance zone, eliminating the risk of secondary drilling offset.

[0071] Specifically, this technical solution achieves a hierarchical positioning system through a composite carrier plate structure. A small area of ​​the first carrier plate is used for high-precision machining of the first through-hole and the first target point. A standard-sized area of ​​the second carrier plate, after identifying the first target point using X-ray equipment, generates a second target point. The distance between the two is controlled within a specific range to avoid accumulated tolerances. A cured dielectric material layer fills the first through-hole to form a stable dielectric layer, ensuring the structural integrity during the machining of the second through-hole. The second through-hole is strictly confined within the projection range of the first through-hole. Using the first through-hole as a positional tolerance zone, even with slight offsets, the second through-hole is guaranteed to be completely located inside the first through-hole, avoiding hole wall damage or open circuits caused by alignment errors.

[0072] Existing technologies rely on mechanical alignment tools for secondary through-hole positioning, which is prone to alignment misalignment due to accumulated tolerances from multiple machining processes. This solution, however, generates a second target point using non-contact X-ray positioning, directly offsetting the coordinates based on the initial reference, thus eliminating mechanical alignment errors. Simultaneously, a composite carrier structure separates the small-size, high-precision machining area from the large-size, standard machining area, avoiding deformation errors caused by a single-size carrier during multiple machining processes.

[0073] Through the above technical solution, this application solves the problem of alignment misalignment during secondary machining of through holes in large-size electronic carrier wafers. By using a graded positioning system and a non-contact positioning method, the influence of cumulative tolerances on the accuracy of secondary drilling is effectively eliminated. By using a structure design with a large hole surrounding a small hole, the first through hole is used as a position tolerance zone to ensure that the second through hole is always located in the predetermined area, avoiding hole misalignment or hole wall damage caused by offset, thereby reducing the product scrap rate.

[0074] This application further proposes that when performing secondary processing on the through hole formed in the first processing, the diameter of the first through hole is set to be significantly larger than the diameter of the through hole formed in the secondary processing.

[0075] The initial through-hole diameter refers to the diameter of the hole penetrating the substrate formed during the initial processing. This can be achieved using laser ablation or mechanical drilling, and its size must provide sufficient positional tolerance for subsequent secondary processing. The secondary through-hole diameter refers to the diameter of the hole formed by reprocessing the initial through-hole. This can be achieved using high-precision laser drilling or micro-drilling, and its size must meet the requirements of uniform hole wall coverage in the through-hole plating process.

[0076] Specifically, the diameter of the initial through-hole is set to 6 or 10 times that of the through-hole formed in the secondary processing, ensuring sufficient positional offset within the projection range of the initial through-hole. This stepped diameter design allows for a certain degree of alignment deviation during secondary processing while ensuring that the secondary through-hole is completely within the open area formed by the initial through-hole. The difference in diameter between the two processing steps retains the process tolerance provided by using a large diameter in the initial processing, while also creating a small-diameter structure that meets the requirements for through-hole plating during the secondary processing.

[0077] Compared to existing technologies, when directly machining small through holes on a substrate, the limitations in machining accuracy can easily lead to hole position deviations exceeding the allowable range. This application, however, processes through holes of different diameters in stages. During the initial machining, a large-diameter through hole is formed as a positioning reference area for the secondary machining, effectively reducing the accuracy requirements for the secondary machining and enabling hole position control without relying on a high-precision positioning system during the secondary through hole machining process.

[0078] Through the above technical solution, this application solves the problem of hole displacement into the solid area of ​​the substrate due to equipment positioning errors during secondary hole processing, thus avoiding defects such as incomplete hole wall plating or residual voids in the hole. Simultaneously, the stepped hole diameter structure provides a hole diameter size that meets the requirements of metal deposition for the hole-filling electroplating process, ensuring uniform filling of the hole with electroplating material.

[0079] This application further proposes a technical solution of setting at least two non-overlapping second through holes within a single first through hole.

[0080] In this design, a single first through-hole refers to a through-hole structure pre-processed on the substrate, which can be achieved using laser etching or mechanical drilling processes. Its spatial range defines the area for secondary processing. This feature creates physical constraints by limiting the processing position of the second through-hole to within the boundaries of the existing through-hole. The non-overlapping second through-holes refer to multiple independent holes maintaining a distance between them, which can be achieved using coordinate offset positioning technology. Pre-set hole spacing parameters ensure that the hole walls do not contact each other. This feature eliminates structural defects caused by overlapping holes by forcibly isolating the hole layout.

[0081] Specifically, during the substrate processing, a first through-hole of fixed size is first formed as the initial processing area. In the secondary drilling stage, an optical positioning system identifies the boundary coordinates of the first through-hole and automatically generates multiple processing points based on a preset hole distribution pattern. A safe distance is maintained between each processing point to ensure that the drill bit's movement trajectory does not interfere. The drilling depth control module synchronously adjusts the drill bit's downward pressure, ensuring that the formed second through-hole completely penetrates the dielectric material layer without exceeding the projection range of the first through-hole.

[0082] In existing technologies, when machining multiple small holes within a single through-hole, relying solely on a single alignment reference, hole offsets and overlaps are easily caused by repeated positioning errors in the equipment. Existing technologies lack a hole spacing control mechanism, failing to avoid hole wall contact problems caused by accumulated tolerances. This solution establishes a spatial constraint mechanism based on the initial through-hole boundary, combined with a multi-hole distribution algorithm, achieving precise control of the hole layout and effectively preventing hole overlap caused by alignment deviations during secondary drilling, thus avoiding structural strength weakening issues caused by hole wall contact. Simultaneously, it eliminates closed cavities created by hole overlap during electroplating, ensuring complete filling of the through-hole structure with dielectric material. This solution significantly improves through-hole machining accuracy and product reliability while maintaining high-density drilling requirements.

[0083] This application further proposes that the ratio of the diameter of the first through hole to the diameter of the second through hole is 100:5 ~ 100:90.

[0084] The first through-hole diameter refers to the diameter of the through-hole initially formed on the substrate, which can be achieved using laser-induced etching or mechanical drilling. This size provides a reference space for subsequent dielectric material filling and secondary processing. The second through-hole diameter refers to the diameter of the through-hole formed after dielectric material filling and secondary processing, which can be achieved using laser drilling or chemical etching. This size must meet the minimum hole diameter requirements of the electroplating filling process.

[0085] Specifically, after forming a large-sized first through-hole on the substrate, a flat surface is formed by filling it with a thermosetting dielectric material. When performing secondary drilling, since the second through-hole is significantly smaller than the first through-hole, its processing position can be completely within the projection coverage area of ​​the first through-hole. This size difference design limits the positioning deviation of the secondary drilling to within the boundary of the first through-hole. Even if there is a positional offset of the processing equipment, it can still ensure that the second through-hole and the first through-hole form a nested structure, avoiding hole wall damage caused by offset exceeding the boundary.

[0086] Existing technologies require precise alignment with the original through-hole center during secondary drilling, placing extremely high demands on equipment accuracy. This solution, however, constructs a nested structure with two levels of hole diameters, transforming the positioning accuracy requirement into a containment relationship between hole diameters. This ensures the integrity of the through-hole structure within allowable deviations, effectively resolving the contradiction between the difficulty of electroplating and filling large through-holes and the misalignment during secondary drilling. By setting the dimensional ratio between the two levels of through-holes, it ensures that the through-hole formed in the initial processing has sufficient space to accommodate dielectric material filling, while also ensuring that the smaller holes formed in the secondary processing maintain structural effectiveness even with positional deviations. This improves product yield and reduces equipment accuracy requirements.

[0087] This application further proposes that the dielectric material layer is ABF resin, and its filling depth covers the entire depth of the first through hole.

[0088] ABF resin refers to a thermosetting resin material with specific flow properties. Specifically, it can be melted and flowed by heating it above its glass transition temperature. Its low viscosity facilitates the full filling of the through-hole under pressure. The filling depth covering the entire length of the first through-hole means that the dielectric material, after curing, completely occupies the space within the hole along its axial direction. This can be achieved by controlling the pressing pressure and temperature gradient to continuously fill the material along the depth of the through-hole. This feature ensures that there are no unfilled areas inside the through-hole.

[0089] Specifically, ABF resin forms a low-viscosity molten state during heating. Through a pressing process, the resin flows into the first through-hole, achieving bottom-up, layer-by-layer filling under temperature control. When the filling depth covers the entire length of the through-hole, the resin, after curing, forms a continuous medium layer that adheres tightly to the inner wall of the through-hole, eliminating cavities or air gaps caused by incomplete filling. This medium layer provides uniform physical support for subsequent drilling, preventing displacement of the secondary drilling reference position due to localized material collapse.

[0090] This solution uses ABF resin and combines it with full-depth filling control. Through the synergistic optimization of material properties and process parameters, it ensures that a defect-free and dense filling structure is formed inside the through-hole. This solves the problem of residual voids in the through-hole caused by incomplete filling of dielectric material, eliminates the risk of secondary drilling alignment deviation and structural reliability caused by voids, and provides a void-free substrate structure for subsequent electroplating processes, ensuring the uniformity and integrity of the electroplated layer inside the through-hole.

[0091] This invention provides a method for processing through-holes in multi-size electronic carrier sheets, characterized by the following steps: providing a first carrier sheet Core layer, simultaneously processing a plurality of first through-holes and at least two first target points on the small-sized rigid substrate, the first target points being distributed at both ends of the substrate; embedding the first carrier sheet Core layer into a hollow frame-shaped second carrier sheet Core layer to form a composite carrier sheet structure, wherein the inner diameter of the second carrier sheet matches the outer edge of the first carrier sheet; pressing thermosetting dielectric material onto both sides of the composite carrier sheet, so that the dielectric material fills the first through-holes; identifying the first target points using an X-ray device, and drilling a second target point 5-50 mm away from the first target point within the region of the second carrier sheet; using the second target point as an alignment reference, drilling a second through-hole with a diameter smaller than the first through-hole within the projection range of the first through-hole. This invention has the advantages of improving the alignment accuracy of through-holes in the composite carrier sheet structure, reducing the risk of thermoforming deformation, and improving product yield.

[0092] The above embodiments are illustrative of the principles and effects of the present invention and are not intended to limit the invention. Those skilled in the art can make modifications to the above embodiments without departing from the spirit and scope of the invention. Therefore, the scope of protection of the present invention should be as set forth in the claims.

Claims

1. A method for processing a through hole of a multi-size electronic carrier tape, characterized by, The method comprises the following steps: A first carrier sheet Core layer is provided, which is a small-size rigid substrate, and a plurality of first through holes and at least two first target points are formed on the small-size rigid substrate synchronously, and the first target points are distributed at both ends of the substrate; The first carrier sheet Core layer is embedded into a hollow frame-shaped second carrier sheet Core layer to form a composite carrier sheet structure, wherein the inner diameter of the second carrier sheet matches the outer edge of the first carrier sheet; A thermosetting dielectric material is compressed on both sides of the composite carrier sheet, so that the dielectric material fills the first through holes; The first target points are identified by an X-ray device, and second target points are drilled at a distance of 5-50 mm from the first target points in the second carrier sheet region; The second target points are used as alignment references, and second through holes with a smaller aperture than the first through holes are drilled in the projection range of the first through holes.

2. The method of claim 1, wherein, The ratio of the aperture of the first through holes to the aperture of the second through holes is 100:5-100:

90.

3. The method of claim 1, wherein, A plurality of second through holes that do not overlap each other are drilled in a single first through hole.

4. The method of claim 1, wherein, The first target points and the first through holes are completed synchronously by laser-induced etching.

5. The method of claim 1, wherein, The dielectric material is ABF or Prepreg resin.

6. The method of claim 1, wherein, The first target points are arranged on the first carrier sheet Core layer.

7. A multi-size electronic carrier tape, characterized by, The method comprises: A composite carrier sheet Core layer is formed by a small-size first carrier sheet Core layer embedded inside and a hollow second carrier sheet Core layer outside; The first carrier sheet Core layer is provided with at least two first target points and a plurality of first through holes; A solidified dielectric material layer is filled in the first through holes; Second target points are arranged on the second carrier sheet Core layer, and the positions of the second target points are generated based on the first target points by X-ray positioning, and the distance between the nearest first target point and the second target point is 5-50 mm; Second through holes are drilled through the dielectric material layer and the first through holes, and the aperture of the second through holes is smaller than that of the first through holes and completely located in the projection range of the first through holes.

8. The electronic carrier sheet as claimed in claim 7, characterized in that The ratio of the aperture of the first through holes to the aperture of the second through holes is 100:5-100:

90.

9. The electronic carrier sheet as claimed in claim 7, characterized in that At least two second through holes that do not overlap each other are contained in a single first through hole.

10. The electronic carrier sheet as claimed in claim 7, wherein The dielectric material layer is ABF resin, and the filling depth covers the full longitudinal depth of the first through holes.

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