Anti-warping IC carrier plate with edge supporting structure

Abstract

The invention discloses an anti-warping IC carrier plate with an edge supporting structure, and the anti-warping IC carrier plate remarkably reduces the warping deformation of a substrate through the design of edge special holes and thermal mechanical compensation. The H-shaped copper column frame and the gradient aperture / spacing design can compensate according to the asymmetry degree of a substrate pattern, so that the warping of the whole board is reduced; v-shaped or Y-shaped holes are designed according to angles, directional support and bending moment resistance are generated, and corner warping is particularly restrained; a shape memory polymer (SMP) or a thermal shrinkage and cold expansion insert containing a negative thermal expansion (NTE) filler is embedded in a specific position, shrinks at a high temperature to enable the substrate to normally release residual stress, and recovers the supporting property at a room temperature; the existing process of the PCB is continued, special equipment does not need to be newly added, and mass production is easy; under the double compensation of the structure and the material, the metal / polymer in the substrate is crystallized in a low-stress environment, and the overall stability of the substrate is improved.

Description

Technical Field

[0001] This invention relates to the field of printed circuit board processing technology, and in particular to an anti-warping IC carrier board with an edge support structure. Background Technology

[0002] The description in this section provides only background information related to the disclosure of this invention and does not constitute prior art.

[0003] As the semiconductor industry continues to evolve, IC substrates are moving towards high-density interconnects and multi-chip integration, especially in 2.5D and 3D packaging architectures. A single substrate often needs to accommodate multiple chips with different functions, such as image processing chips, AI chips, and memory modules. This highly integrated layout leads to asymmetry in circuit design. Furthermore, the trend towards thinner and smaller products has resulted in a gradual reduction in substrate thickness and dielectric layer thickness, leading to a decrease in overall structural rigidity. Under these conditions, substrates are highly susceptible to warping during thermal processing, disassembly, or automated handling. Excessive warping can cause products to fail to meet customer specifications, resulting in scrap. On the other hand, it also poses risks of board jamming, breakage, or edge damage during automated loading / unloading or transfer devices, directly impacting production efficiency and yield.

[0004] Existing solutions mostly focus on material replacement or symmetrical structural design. For example, some manufacturers attempt to replace standard dielectric layers with high-end materials that have lower coefficients of thermal expansion or higher structural stability to reduce deformation caused by thermal stress. However, these materials are often expensive, and there are concerns about supply chain stability and cost competitiveness when introducing them into mass production. In addition, there are methods to balance the non-uniformity of copper density by designing dummy patterns on the circuit surface, but this method mainly improves the asymmetry of local patterns and has limited effect on the overall structural support of the board edges, especially in automated transfer processes.

[0005] It should be noted that the above description of the technical background is only for the purpose of providing a clear and complete explanation of the technical solutions of the present invention and facilitating understanding by those skilled in the art. It should not be assumed that the above technical solutions are known to those skilled in the art simply because they have been described in the background section of this invention. Summary of the Invention

[0006] The technical problem to be solved by the present invention is to provide an anti-warping IC carrier board with an edge support structure, which addresses the shortcomings of the prior art.

[0007] This application discloses an anti-warping IC carrier board with an edge support structure, comprising: The substrate includes an effective circuit area in the middle and an ineffective area around the perimeter of the effective circuit area. Multiple through holes are provided in the ineffective area. The through holes are formed into copper pillars after copper plating and electroplating. The copper pillars include V-shaped copper pillars, Y-shaped copper pillars and / or H-shaped copper pillar structures. The substrate has a thermal shrinkable and cold expandable insert embedded in its main stress area. The thermal shrinkable and cold expandable insert is introduced into the substrate by slotting, pre-embedded lamination, or partial filling molding. The thermal shrinkable and cold expandable insert is a shape memory polymer filler or a filler containing negative thermal expansion.

[0008] Furthermore, in the aforementioned anti-warping IC carrier board with edge support structure, the H-shaped copper pillars include at least two rows of through-hole arrays arranged along the edge extension direction of the board. The outer row of through-hole pillars is close to the outer edge of the board, and the inner row of through-hole pillars is close to the effective circuit area. The two rows of through-hole pillars are connected by at least one section of transverse metal connection structure, and the H-shaped copper pillars form a continuous or segmented frame beam.

[0009] Furthermore, in the aforementioned anti-warping IC carrier board with edge support structure, the V-shaped copper pillars or Y-shaped copper pillars include two rows or two sets of inclined perforated pillars, with the two sets of perforated pillars forming an angle in the edge region, the angle being set according to the main warping direction and the position of the asymmetric dominant area.

[0010] Furthermore, in the aforementioned anti-warping IC carrier board with edge support structure, the included angle ranges from 30° to 85°.

[0011] Furthermore, in the aforementioned anti-warping IC carrier board with edge support structure, the Y-shaped copper pillar includes at least three support paths, and the Y-shaped copper pillar and the local copper strip form a grid beam structure.

[0012] Furthermore, in the aforementioned anti-warping IC substrate with edge support structure, thermally shrinkable and expandable inserts are embedded in the edge or main stress area of ​​the substrate. Furthermore, in the aforementioned anti-warping IC substrate with edge support structure, the warping-dominant edge of the substrate is provided with the H-shaped copper pillar, the opposite edge is provided with V-shaped or Y-shaped perforations, the corner is provided with the Y-shaped copper pillar, and the main stress area of ​​the substrate is provided with the heat-shrinkable and cold-expandable insert, which is staggered with the copper pillar.

[0013] Furthermore, in the aforementioned anti-warping IC carrier board with edge support structure, the main force-bearing area of ​​the substrate includes: a vacuum nozzle contact area, a mechanical gripper holding area, a conveyor belt support point, and a fixture positioning support point, etc.

[0014] Furthermore, in the aforementioned anti-warping IC carrier plate with edge support structure, the shape memory polymer filler is a thermosetting or thermoplastic shape memory polymer, or a shape memory polymer composite material, and the filler containing negative thermal expansion is a composite material in which negative thermal expansion particles or fibers are dispersed in a polymer matrix.

[0015] In summary, the method used in the embodiments of the present invention has the following advantages: The anti-warping IC substrate with edge support structure described in this invention significantly reduces substrate warpage through special edge hole design and thermomechanical compensation. The H-shaped copper pillar frame and gradient hole diameter / spacing design can compensate for substrate asymmetry, reducing overall board warpage. The V-shaped or Y-shaped holes are designed at angles to generate directional support and anti-bending moment, especially suppressing corner warpage. Shape memory polymer (SMP) or filler containing negative thermal expansion (NTE) is embedded in specific positions. At high temperatures, the substrate shrinks to release residual stress normally, and at room temperature, it restores support. The thermal shrinkage and expansion of the insert and the copper pillar structure form a complementary mechanism. The copper pillar provides "geometric and structural stiffness support," which is effective at room temperature and across the entire temperature range. The insert provides temperature-responsive stress adjustment, releasing stress at high temperatures and providing springback support at cooling. The combination of the two can improve warpage control from single stiffness suppression to cross-temperature adaptive suppression. It uses existing PCB processes without the need for additional special equipment, making it easy to mass-produce. With dual compensation of structure and materials, the metal / polymer in the substrate crystallizes in a low-stress environment, improving the overall stability of the substrate.

[0016] To further understand the features and technical content of the present invention, please refer to the following detailed description and drawings of the present invention. However, the drawings provided are for reference and illustration only and are not intended to limit the present invention. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments or prior art of this specification, the drawings used in the description of the embodiments or prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in this specification. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Figures 1 to 4 These are schematic diagrams illustrating different copper pillar arrangements of an anti-warping IC carrier board with edge support structure in embodiments of the present invention. Figure 5 This is a schematic diagram of the H-shaped copper column in an embodiment of the present invention.

[0019] The reference numerals in the above figures are: 1. Substrate; 2. Through hole; 3. Copper pillar; 4. Thermal shrinking and expanding insert. Detailed Implementation

[0020] To enable those skilled in the art to better understand the technical solutions in this specification, the technical solutions in the embodiments of this specification will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this specification, and not all embodiments. Based on the embodiments in this specification, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of this specification.

[0021] The following specific embodiments illustrate the implementation of the present invention. Those skilled in the art can understand the advantages and effects of the present invention from the content disclosed in this specification. The present invention can be implemented or applied through other different specific embodiments, and various details in this specification can also be modified and changed based on different viewpoints and applications without departing from the concept of the present invention. Furthermore, the accompanying drawings of the present invention are for simple illustrative purposes only and are not depictions of actual dimensions; this is stated in advance. The following embodiments will further describe the relevant technical content of the present invention in detail, but the disclosed content is not intended to limit the scope of protection of the present invention.

[0022] It should be understood that while terms such as "first," "second," and "third" may be used in this document to describe various components or signals, these components or signals should not be limited by these terms. These terms are primarily used to distinguish one component from another, or one signal from another. Furthermore, the term "or" as used herein should, as appropriate, include any combination of one or more of the related listed items.

[0023] Reference Figures 1 to 5 As shown in the figure, this application discloses an anti-warping IC carrier with an edge support structure, comprising: The substrate 1 includes an effective circuit area in the middle and an ineffective area around the perimeter of the effective circuit area. Multiple through holes 2 are provided in the ineffective area. The through holes 2 are formed into copper pillars 3 after copper plating and electroplating. The copper pillars 3 include V-shaped copper pillars 3, Y-shaped copper pillars 3 and / or H-shaped copper pillars 3 structures. The copper pillars 3 can form an integrated structure with the edge metal cladding layer of the substrate 1, so that the edge forms a continuous conductive / thermal conductive frame. The copper pillars 3 can form stepped support at different stacking depths. For example, thicker copper pillars 3 are formed in the layer near the core board and thinner copper pillars 3 are formed near the surface layer to balance rigidity and manufacturability. The substrate 1 has a thermal shrinkage and expansion insert 4 embedded in its main stress area.

[0024] Specifically, in this embodiment, the H-shaped copper pillar 3 includes at least two rows of through-holes 2 arranged along the edge of the board. The outer row of through-holes is close to the outer edge of the board, and the inner row of through-holes is close to the effective circuit area. The two rows of through-holes are mechanically coupled through at least one transverse metal connection structure (e.g., electroplated copper bridge, copper strip, or continuous copper beam), thereby forming an equivalent cross-section "similar to an I-beam / box beam", significantly improving the moment of inertia and bending stiffness of the edge section. The H-shaped copper pillar 3 forms a continuous or segmented edge beam. Continuous refers to forming a continuous support path along one side edge; segmented refers to setting discontinuities or buffer sections at predetermined positions. The discontinuities can correspond to cutting paths, positioning holes, process notches, or stress release areas, so that the edge beam provides rigid support while retaining a certain degree of compliance, avoiding excessive restraint that leads to local interlayer peeling or cracking. This improves edge stiffness and enhances the symmetry of the substrate 1. If the aperture and spacing are designed in a gradient according to the degree of asymmetry of the internal circuit of the substrate 1, local warping caused by pattern differences can be further compensated.

[0025] Specifically, in this embodiment, the V-shaped copper column 3 or Y-shaped copper column 3 includes two rows or two sets of inclined perforated columns. The two sets of perforated columns form an angle at the edge region. The angle is set according to the main warping direction and the position of the asymmetric dominant area. The range of the angle is 30°~85°, so that the resultant force direction of the V-shaped support corresponds to the bending direction that needs to be counteracted. The V-shaped copper column 3 points to the asymmetric dominant area at a specific angle, forming a directional bending moment. The V-shaped or Y-shaped copper column 3 points to the asymmetric dominant area at a specific angle, forming a directional bending moment. V-shaped or Y-shaped holes have special advantages. The geometric design of the V-shaped structure can simulate the stress mode of an arch bridge or pier. When the plate is heated or stressed, the V-shaped copper column 3 can disperse and transmit stress downward, forming a bending moment, which is particularly helpful in suppressing corner warping.

[0026] When the plate exhibits a bending tendency along the dominant direction after heating, the inclined arrangement of the V-shaped perforations mechanically generates force decomposition: one part forms a tensile / compressive constraint along the plate surface, and the other part forms a supporting reaction force along the plate thickness. Together, they form an equivalent bending moment, thereby suppressing edge warping or sagging. Especially in the corner area, warping is often accompanied by a torsional component (i.e., the plate corner warps and the edge deforms simultaneously in two directions); due to its directionality, the V-shaped perforations can provide preferential support for a certain dominant torsional direction, thereby reducing the corner warping peak and corner curvature gradient, and reducing the risk of microcracks or interface delamination caused by corner stress concentration.

[0027] Specifically, in this embodiment, the Y-shaped copper pillar 3 includes at least three support paths, and the Y-shaped copper pillar 3 and the local copper strip form a grid beam structure. The Y-shaped perforated mesh can provide support in multiple directions, further improving the stability of the substrate 1 edge.

[0028] The advantages of the Y-shaped design are: it provides support in multiple directions and distributes loads, giving the edge area a more balanced resistance to deformation from thermal stress and external forces from different directions. The Y-shaped mesh can further form a "grid beam" structure with local copper strips, i.e., a multi-cell support network is formed by electroplated copper bridges between the perforated columns; this network can significantly improve the equivalent stiffness and fatigue resistance of the edge area without significantly increasing material costs. It should also be noted that the "V-shaped" and "Y-shaped" in this invention are not limited to strict letter shapes; the key lies in the topological relationship and directionality of the support path: the V-shaped design emphasizes the directional bending moment resistance formed by bidirectional diagonal bracing, while the Y-shaped design emphasizes the all-directional support enhancement formed by tri-directional or multi-directional diversion supports.

[0029] Specifically, in this embodiment, a thermally shrinkable and cold-expandable insert 4 is embedded in the edge or main stress-bearing area of ​​the substrate 1. Specifically, in this embodiment, the substrate 1 has an H-shaped copper pillar 3 on the warped dominant edge, a V-shaped or Y-shaped mesh on the opposite edge, a Y-shaped copper pillar 3 at the corner, and a heat-shrinkable and cold-expandable insert 4 in the main stress area of ​​the substrate 1. The heat-shrinkable and cold-expandable insert 4 is staggered with the copper pillar 3.

[0030] In one embodiment, the "dominant warpage edge" can be determined first by measurement or simulation: for example, after reflow or thermal cycling, if the maximum warpage displacement occurs at a certain edge or corner, then that edge is defined as the dominant edge; H-shaped frame beams are set on the dominant edge to provide maximum edge stiffness and improve the overall bending resistance of the plate. The reason for setting V-shaped or Y-shaped perforated meshes on opposite sides is that when the stiffness of the dominant edge is increased, the plate may experience "mechanical imbalance" leading to relative displacement on opposite sides; introducing directional support on opposite sides can form a coupled structure of "main frame beam + opposite side directional support", suppressing overall bending and reducing the probability of saddle-shaped warpage; in addition, Y-shaped copper columns 3 are set at the corner to deal with the composite load at the corner: the corner is simultaneously subjected to the superposition of thermal stress from the two adjacent sides, the superposition of local external forces from handling clamping / adsorption, and the concentration of residual stress from cutting; the multi-directional support of Y-shaped copper columns 3 can effectively disperse the corner stress and reduce the corner warpage peak value.

[0031] Specifically, in this embodiment, the main stress-bearing area of ​​the substrate 1 includes: a vacuum nozzle contact area, a mechanical gripper holding area, a conveyor belt support point, and a fixture positioning support point, etc. Heat-shrinkable and cold-stretching inserts are provided at these locations to provide support during room temperature handling, release stress during high-temperature processes, and reduce heat-induced deformation locking, thereby simultaneously improving both "process warpage" and "handling warpage".

[0032] Specifically, in this embodiment, the heat shrinking and cold expanding insert 4 is a shape memory polymer (SMP) filler or a filler containing negative thermal expansion (NTE). The shape memory polymer filler is a thermosetting or thermoplastic shape memory polymer, or a shape memory polymer composite material. The filler containing negative thermal expansion is a composite material in which negative thermal expansion particles or fibers are dispersed in a polymer matrix.

[0033] SMP shrinks at high temperatures, which helps release residual stress in substrate 1. When it returns to room temperature, the material recovers its shape and provides support for substrate 1, essentially automatically adjusting its mechanical state during the process cycle. NTE composites can exhibit low or even negative thermal expansion at room temperature, locally reducing the equivalent CTE, and even exhibiting near-zero or negative expansion in certain temperature ranges to offset the thermal expansion difference between copper and resin, forming a complementary mechanism with the copper pillar 3 structure to further balance thermal curvature. SMP inserts can take the form of strips, sheets, rings, or lattice shapes: strips are suitable for extending along the edges to form continuous support; lattice shapes are suitable for local reinforcement corresponding to nozzles or clamping points; ring shapes are suitable for forming closed compensation paths around specific heat or stress sources. The particle size, volume fraction, and dispersion uniformity of NTE fillers can be used to control the equivalent CTE and modulus of the composite: smaller particle size is beneficial for uniform dispersion and reducing local stress concentration; higher volume fraction can obtain a stronger CTE compensation effect but may increase brittleness; therefore, comprehensive optimization can be performed according to the target warp function and reliability requirements.

[0034] Specifically, in this embodiment, the heat-shrinkable and cold-expandable insert 4 is introduced into the substrate 1 through slotting, pre-embedded lamination, or partial filling molding. For example, a groove is pre-fabricated in the core board or building layer, and the SMP / NTE composite is placed in it and then co-laminated and cured with resin; or the composite is injected and cured in the edge ineffective area through a filling process; this process can use existing PCB / carrier board manufacturing equipment, only requiring the addition of corresponding process fixtures or process nodes. The heat-shrinkable and cold-expandable insert can exhibit different modulus platforms in different temperature zones, thereby achieving segmented stress adjustment in the curing temperature and room temperature ranges.

[0035] The thermal shrinking and expanding insert 4 and the copper pillar 3 form a complementary mechanism. The copper pillar 3 provides "geometric and structural stiffness support", which is effective in both room temperature and full temperature range. The insert provides temperature-responsive stress adjustment, which releases stress in the high temperature range and provides springback support in the cooling range. The combination of the two can improve warpage control from single stiffness suppression to cross-temperature adaptive suppression.

[0036] By utilizing the structure described above in this embodiment, the warpage deformation of substrate 1 is significantly reduced through the special edge hole design and thermomechanical compensation; the H-shaped copper pillar 3 frame and gradient hole diameter / spacing design can compensate for the asymmetry of the substrate 1 pattern, reducing overall board warpage; the V-shaped or Y-shaped holes are designed according to angles to generate directional support and anti-bending moment, especially suppressing corner warpage; shape memory polymer (SMP) or filler containing negative thermal expansion (NTE) is embedded in specific positions, which shrinks at high temperatures to allow substrate 1 to release residual stress normally, and restores support at room temperature; the existing PCB process is used, without the need for additional special equipment, making mass production easy; under the dual compensation of structure and materials, the metal / polymer in substrate 1 crystallizes in a low-stress environment, improving the overall stability of substrate 1.

[0037] The content disclosed above is only a preferred and feasible embodiment of the present invention, and is not intended to limit the scope of the patent application of the present invention. Therefore, all equivalent technical changes made using the contents of the present invention specification and drawings are included in the scope of the patent application of the present invention.

[0038] The various embodiments in this specification are described in a progressive manner. The same or similar parts between the various embodiments can be referred to each other. Each embodiment focuses on describing the differences from other embodiments.

[0039] Although this application has been described by way of examples, those skilled in the art will know that this application has many modifications and variations without departing from the spirit of this application, and it is intended that the appended embodiments include these modifications and variations without departing from this application.

Claims

1. An anti-warping IC carrier board with an edge support structure, characterized in that, include: The substrate includes an effective circuit area in the middle and an ineffective area around the perimeter of the effective circuit area. Multiple through holes are provided in the ineffective area. The through holes are formed into copper pillars after copper plating and electroplating. The copper pillars include V-shaped copper pillars, Y-shaped copper pillars and / or H-shaped copper pillar structures. The substrate has a thermally shrinkable and cold-expandable insert embedded in its main stress area. The thermally shrinkable and cold-expandable insert is introduced into the substrate by slotting, pre-embedded lamination, or partial filling molding. The thermally shrinkable and cold-expandable insert is a shape memory polymer filler or a filler containing negative thermal expansion.

2. The anti-warping IC carrier board with edge support structure according to claim 1, characterized in that, The H-shaped copper pillar includes at least two rows of through-hole arrays arranged along the edge of the plate. The outer row of through-hole pillars is close to the outer edge of the plate, and the inner row of through-hole pillars is close to the effective circuit area. The two rows of through-hole pillars are connected by at least one section of transverse metal connection structure. The H-shaped copper pillar forms a continuous or segmented frame beam.

3. The anti-warping IC carrier board with edge support structure according to claim 1, characterized in that, The V-shaped or Y-shaped copper pillars include two rows or two groups of inclined perforated pillars, with the two groups of perforated pillars forming an angle at the edge region. The angle is set according to the main warping direction and the position of the asymmetric dominant area.

4. The anti-warping IC carrier board with edge support structure according to claim 3, characterized in that, The included angle ranges from 30° to 85°.

5. The anti-warping IC carrier board with edge support structure according to claim 1, characterized in that, The Y-shaped copper column includes at least three support paths, and the Y-shaped copper column and the local copper strip form a grid beam structure.

6. The anti-warping IC carrier board with edge support structure according to claim 1, characterized in that, The substrate has thermal shrinkage and expansion inserts embedded in its edge or main stress area.

7. The anti-warping IC carrier board with edge support structure according to claim 1, characterized in that, The substrate has an H-shaped copper pillar on the warped dominant side, a V-shaped or Y-shaped mesh on the opposite side, a Y-shaped copper pillar at the corner, and a heat-shrinkable and cold-expandable insert in the main stress area of ​​the substrate. The heat-shrinkable and cold-expandable insert is staggered with the copper pillar.

8. The anti-warping IC carrier board with edge support structure according to claim 6, characterized in that, The main force-bearing areas of the substrate include: vacuum nozzle contact area, mechanical gripper holding area, conveyor belt support point, and fixture positioning support point, etc.

9. The anti-warping IC carrier board with edge support structure according to claim 1, characterized in that, The shape memory polymer filler is a thermosetting or thermoplastic shape memory polymer, or a shape memory polymer composite material, and the filler containing negative thermal expansion is a composite material in which negative thermal expansion particles or fibers are dispersed in a polymer matrix.

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