A warp-resistant package substrate

Abstract

This invention belongs to the field of electronic packaging technology, and specifically relates to an anti-warpage packaging substrate, comprising a packaging substrate and positioning holes, the positioning holes being located at the inner end of the packaging substrate. This invention utilizes side-extended thermally conductive copper strips, main heat lines, side heat sinks, stress grooves, and reinforcing supports. During use, the side-extended thermally conductive copper strips absorb and conduct the working heat of the chip and motherboard on the packaging substrate through the main heat lines, and transfer it to the sides of the packaging substrate through the distribution of the side-extended thermally conductive copper strips until the heat is conducted to the heat sinks, where it is rapidly dissipated through multiple sets of toothed heat sinks. During the high-temperature curing and packaging process, the silicon chip, substrate, and copper material expand or contract significantly with temperature changes. When localized internal stress is generated, the equilateral square grooves at the bottom of the packaging substrate divide the bottom space into small mechanical units, localizing the area of ​​thermal stress. In this process, the copper mesh blocks arranged at a 45° angle form a non-orthogonal support network.

Description

Technical Field

[0001] This utility model relates to the field of electronic packaging technology, specifically to an anti-warping packaging substrate. Background Technology

[0002] As the core carrier of modern electronic packaging, the packaging substrate is a crucial bridge connecting chips and external circuits. With the development of electronic products towards high performance and miniaturization, the packaging substrate not only undertakes the basic functions of electrical interconnection and mechanical support, but also becomes an important platform for solving systemic challenges such as heat dissipation and signal integrity. In fields such as 5G communication, artificial intelligence chips, and automotive electronics, high-performance packaging substrates, through optimized material systems and structural designs, have significantly improved data transmission rates (e.g., achieving 112Gbps / mm²). 2 Wiring density) and power density (supports 1000W / cm²) 2 (Heat dissipation requirements). Its innovative applications have directly driven the evolution of chip integration from 2D to 2.5D / 3D, enabling advanced technologies such as HBM memory stacking and Chiplet heterogeneous integration to be realized.

[0003] The existing technology has the following shortcomings: The existing technology, "An anti-warping packaging substrate" with publication number CN207082522U, "includes a packaging substrate, the packaging substrate has fluorescent patterns around its surface, the fluorescent patterns have spiral holes at both ends and the spiral holes are located on the surface of the packaging substrate, an LED light is provided on one side of the fluorescent pattern and the LED light is connected to the surface of the packaging substrate, a shock-absorbing pad is provided inside the spiral hole, a chip bonding pad is connected to the surface of the packaging substrate, an insulating layer is provided under the chip bonding pad, the insulating layer and the chip bonding pad are connected by a heat dissipation layer, and a steel plate is provided under the insulating layer."

[0004] The aforementioned structure serves to fix and reinforce the substrate, facilitating its location and repair, and ensuring its safe use. However, traditional anti-warping solutions for packaging substrates commonly employ composite structures such as spiral holes, shock-absorbing pads, multi-layer insulation layers, and reinforcing steel plates, artificially increasing the proportion of the substrate's edge structure through mechanical stacking. While this design can suppress deformation in the short term, it introduces significant engineering risks: First, the complex physical stacking structure greatly increases the complexity of disassembly and maintenance, requiring the destructive removal of peripheral components during chip repair or upgrades; second, the overly reinforced outer connection structure hinders the natural release of thermal stress during high-temperature packaging processes (such as reflow soldering at 260°C), leading to abnormal stress accumulation in critical areas inside the substrate (such as below the chip pads), forming localized stress concentration points exceeding the material's yield strength. This undispersed mechanical stress can not only directly trigger the propagation of microcracks in the substrate but also cause cyclic plastic deformation of the peripheral metal structure through stress transmission, ultimately manifesting as failure modes such as connector metal fatigue and solder joint cracking, reducing the substrate's reliability and lifespan by more than 40% (compared to substrates without reinforcement structures). Utility Model Content

[0005] To address the shortcomings of existing technologies, this invention provides an anti-warping packaging substrate, which solves the current problems.

[0006] To achieve the above objectives, the present invention provides the following technical solution: an anti-warping packaging substrate, comprising a packaging substrate and a positioning hole, wherein the positioning hole is formed at the inner end of the packaging substrate.

[0007] The upper end of the packaging substrate is provided with a side-extended thermally conductive copper strip.

[0008] The packaging substrate also includes a stress groove and a reinforcing strip. The stress groove is formed at the bottom end of the packaging substrate, and the reinforcing strip is fixedly connected to the inner wall end face of the stress groove.

[0009] As a preferred technical solution of this utility model, the force-bearing groove is an equilateral square groove structure, and eighty groups are provided, which are equidistantly covering the bottom of the packaging substrate, and the length of each side is 2cm.

[0010] As a preferred technical solution of this utility model, the reinforcing bars are equidistantly distributed in each group of stress grooves, and are distributed at a 45° angle diagonal, with seven groups in each group of stress grooves.

[0011] As a preferred embodiment of this utility model, the side-extended thermally conductive copper strip further includes a main heat wire and a side heat bar. The main heat wire is welded to the side end of the side-extended thermally conductive copper strip, and the side heat bar is welded to the side of the side-extended thermally conductive copper strip facing the packaging substrate.

[0012] As a preferred technical solution of this utility model, the side-extended heat-conducting copper strips are distributed in a curved shape on the upper end of the packaging substrate, and two sets of main heat-conducting wires are provided, which are connected to the two ends of the middle part of the side-extended heat-conducting copper strips in a strip structure.

[0013] As a preferred embodiment of this utility model, the side heat sink is consistent with the side of the packaging substrate, and the unit is composed of multiple sets of copper tooth-shaped structures of the same size.

[0014] As a preferred embodiment of this utility model, the long side of the packaging substrate is provided with four sets of side heat sinks, while the short side is provided with two sets of side heat sinks.

[0015] Compared with the prior art, the present invention provides an anti-warping packaging substrate, which has the following beneficial effects:

[0016] An anti-warping packaging substrate is provided, comprising side-extended thermally conductive copper strips, main heat lines, side heat sinks, stress grooves, and reinforcing supports. In use, the side-extended thermally conductive copper strips absorb and conduct the working heat of the chip and motherboard on the packaging substrate through the main heat lines, and then transfer the heat to the sides of the packaging substrate through the distribution of the side-extended thermally conductive copper strips until it reaches the heat sink, where it is rapidly dissipated through multiple sets of toothed heat sinks. During the high-temperature curing and packaging process, the silicon chip, substrate, and copper material expand or contract significantly with temperature changes, generating localized internal stress. The equilateral square grooves at the bottom of the packaging substrate divide the bottom space into small mechanical units, localizing the range of thermal action and preventing stress from spreading. In this process, copper mesh blocks arranged at a 45° angle form a non-orthogonal support network, guiding stress dispersion along the angle and simultaneously offsetting anisotropic expansion differences. The unidirectional layout of the angled blocks forms a 45° angle with the main CTE expansion direction of the substrate, offsetting lateral expansion differences through shear deformation and reducing the overall warpage.

[0017] Through the above-described setup and process, this packaging substrate prevents warping from occurring in two directions compared to existing anti-warping packaging substrates. First, the redesigned side-extended heat-conducting copper strips extend heat conduction to the sides of the packaging substrate, improving heat conduction efficiency. Second, the combination of stress grooves and reinforcing strips allows the packaging substrate to evenly distribute local stress during thermosetting, preventing deformation caused by excessive local stress and thus preventing edge warping. Compared to existing anti-warping methods using bolt-fixed structures, this method not only eliminates the need for redundant fixing structure design but also reduces the difficulty of disassembly and maintenance. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the overall structure of this utility model;

[0019] Figure 2 This is a schematic diagram showing the location of the bottom force-bearing groove in this utility model;

[0020] Figure 3 This is a schematic diagram showing the distribution of the reinforcing bars in this utility model;

[0021] Figure 4 This is a schematic diagram showing the overall distribution of the side-extended heat-conducting copper strips of this utility model;

[0022] Figure 5 This is a schematic diagram of the side heat sink installation position structure of this utility model.

[0023] In the figure: 1. Packaging substrate; 101. Stress groove; 102. Reinforcing strip; 2. Positioning hole; 3. Side-extended heat-conducting copper strip; 301. Main heat line; 302. Side heat sink. Detailed Implementation

[0024] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0025] In this embodiment: an anti-warping packaging substrate includes a packaging substrate 1 and a positioning hole 2, wherein the positioning hole 2 is formed at the inner end of the packaging substrate 1.

[0026] A side-extended thermally conductive copper strip 3 is provided on the upper end of the packaging substrate 1.

[0027] The packaging substrate 1 also includes a force-receiving groove 101 and a reinforcing support 102. The force-receiving groove 101 is formed at the bottom end of the packaging substrate 1, and the reinforcing support 102 is fixedly connected to the inner wall end face of the force-receiving groove 101.

[0028] In this embodiment, the stress groove 101 has an equilateral square groove structure and eighty groups are provided, and they are equidistantly covering the bottom end of the packaging substrate 1, with a single side length of 2cm; the reinforcing bars 102 are equidistantly distributed in each group of stress grooves 101, and are distributed at a diagonal angle of 45°, with seven groups provided in each group of stress grooves 101.

[0029] Specifically, such as Figure 2 and Figure 3 As shown, the equally spaced square groove structure divides the bottom of the packaging substrate 1 into independent mechanical units, and the space inside the stress groove 101 can not only serve as lateral support for the reinforcing bar 102, but also absorb local stress.

[0030] In this embodiment, the side-extended thermally conductive copper strip 3 also includes a main heat line 301 and a side heat block 302. The main heat line 301 is welded to the side end of the side-extended thermally conductive copper strip 3, and the side heat block 302 is welded to the side of the side-extended thermally conductive copper strip 3 facing the side of the packaging substrate 1. The side-extended thermally conductive copper strip 3 is distributed in a curved shape on the upper end of the packaging substrate 1, and the main heat line 301 is provided in two sets and is connected to the two ends of the middle part of the side-extended thermally conductive copper strip 3 in a strip structure.

[0031] Specifically, such as Figure 1 and Figure 4 as well as Figure 5 As shown, the two sets of main heat lines 301 transfer the heat inside the package substrate 1 to the side-spreading heat-conducting copper strips 3, and conduct the heat to the side heat sink 302 along the distribution direction.

[0032] In this embodiment, the side heat sink 302 is consistent with the side of the packaging substrate 1, and each unit is composed of multiple sets of copper tooth-shaped structures of the same size; the long side of the packaging substrate 1 is provided with four sets of side heat sinks 302, and the short side is provided with two sets of side heat sinks 302.

[0033] Specifically, such as Figure 3 As shown, different numbers of side heat sinks 302 are distributed on the long and short sides, which can make the heat conduction path more evenly distributed.

[0034] The working principle and usage process of this utility model are as follows: When the packaging substrate 1 is used, the side-extended heat-conducting copper strips 3 absorb and conduct the working heat of the chip and motherboard on the packaging substrate 1 through the main heat line 301, and transfer it to the side of the packaging substrate 1 through the distribution of the side-extended heat-conducting copper strips 3 until the heat is conducted to the heat sink, where it is quickly dissipated through the heat sink with multiple sets of toothed structures. During the high-temperature curing and packaging process of the packaging substrate 1, the silicon chip, substrate, and copper material expand or contract significantly with temperature changes. When local internal stress is generated, the equilateral square groove at the bottom of the packaging substrate 1 divides the bottom space into small mechanical units, localizing the range of thermal action and preventing stress from expanding and being conducted. In this process, the copper mesh blocks arranged at a 45° angle form a non-orthogonal support network, guiding the stress to be dispersed along the angle and simultaneously offsetting the anisotropic expansion differences. The unidirectional layout direction of the inclined blocks forms a 45° angle with the main CTE expansion direction of the substrate, offsetting the lateral expansion and contraction differences through shear deformation and reducing the overall warpage curvature.

[0035] Finally, it should be noted that the above description is merely a preferred embodiment of this utility model and is not intended to limit the utility model. Although the utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this utility model should be included within the protection scope of this utility model.

Claims

1. An anti-warping packaging substrate, comprising a packaging substrate (1) and a positioning hole (2), wherein the positioning hole (2) is formed at the inner end of the packaging substrate (1), characterized in that: The upper end of the packaging substrate (1) is provided with a side-extended heat-conducting copper strip (3); The packaging substrate (1) also includes a force-receiving groove (101) and a reinforcing support (102). The force-receiving groove (101) is opened at the bottom end of the packaging substrate (1), and the reinforcing support (102) is fixedly connected to the inner wall end face of the force-receiving groove (101).

2. The warpage-resistant package substrate of claim 1, wherein: The force-bearing groove (101) has an equilateral square groove structure and eighty groups are provided, which are equidistantly covering the bottom of the packaging substrate (1), and the length of one side is 2cm.

3. The warpage-resistant package substrate of claim 1, wherein: The reinforcing bars (102) are equidistantly distributed in each set of stress grooves (101) and are arranged at a 45° angle diagonal, with seven sets in each set of stress grooves (101).

4. The warpage-resistant package substrate of claim 1, wherein: The side-extended thermally conductive copper strip (3) also includes a main heat wire (301) and a side heat block (302). The main heat wire (301) is welded to the side end of the side-extended thermally conductive copper strip (3), and the side heat block (302) is welded to the side of the side-extended thermally conductive copper strip (3) facing the packaging substrate (1).

5. The anti-warping packaging substrate according to claim 4, characterized in that: The side-spreading heat-conducting copper strips (3) are distributed in a curved shape on the upper end of the packaging substrate (1), and the main heat lines (301) are provided in two sets, which are connected in a strip structure to the two ends of the middle part of the side-spreading heat-conducting copper strips (3).

6. The warpage-resistant package substrate of claim 4, wherein: The side heat sink (302) is consistent with the side of the packaging substrate (1), and the unit is composed of multiple sets of copper tooth-shaped structures of the same size.

7. The warpage-resistant package substrate of claim 4, wherein: The long side of the packaging substrate (1) is provided with four sets of side heat sinks (302), while the short side is provided with two sets of side heat sinks (302).

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