Ultra-long high-speed wiring chip interface carrier plate capable of avoiding influence of glass fiber effect
By rotating the core layer and the prepreg layer in opposite directions by the same angle in the chip interface carrier, the uniformity of the DK variation of the glass fiber and resin dielectric is improved, solving the problems of increased insertion loss and resonance caused by the glass fiber effect, and achieving performance improvement at high frequencies.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- 零壹半导体技术(常州)有限公司
- Filing Date
- 2025-05-30
- Publication Date
- 2026-05-19
AI Technical Summary
Existing technologies struggle to effectively eliminate the increased insertion loss and resonance issues caused by the fiberglass effect on ultra-long, high-speed signal lines. Furthermore, rotating the plate angle leads to reduced plate utilization and increased costs.
By rotating the core layer and the prepreg layer in opposite directions by the same angle, the uniformity of the DK variation of the fiberglass and resin media is improved. Flat fiberglass cloth and resin covering are used to ensure that the copper-clad part is consistent with the wiring direction of the board.
While maintaining the same material utilization rate, the resonant point of the chip interface carrier at high frequencies was increased, the resonance effect of the glass fiber effect was reduced, impedance fluctuations were improved, and the influence of the glass fiber effect was avoided.
Smart Images
Figure CN224265180U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of chip circuit board technology, and more specifically, it relates to a chip interface carrier board with ultra-long high-speed traces to avoid the influence of glass fiber effect. Background Technology
[0002] As chip signal rates increase, the performance requirements for chip test interface system carrier boards, which serve as carriers for high-speed signal transmission in chip testing, are becoming increasingly stringent.
[0003] To meet the performance testing requirements of high-speed chip interfaces, chip test interface system carrier boards employ ultra-long high-speed signal lines. Due to the considerable length of these high-speed signal lines, the PN phase mismatch and periodic impedance changes caused by the fiberglass effect of the carrier board material result in significant insertion loss resonance at specific frequency bands. By simultaneously rotating the angles of the carrier board material (PP, prepreg) and the core, the resonant frequency of the insertion loss curve caused by the fiberglass effect can be shifted to a higher frequency, thus offsetting the high-speed signal frequency range.
[0004] Patent CN219145726U discloses a core board assembly and circuit board structure. The base is formed by weaving warp and weft layers, eliminating the glass fiber effect and reducing material waste caused by rotating the board during production. Although flattened woven glass fiber cloth can improve the glass fiber effect, the dielectric constant (DK) of glass fiber and resin still differ. Furthermore, the high-speed lines on the chip test interface system carrier board are very long, and the cumulative effect of the glass fiber effect can still produce significant resonance, leading to increased insertion loss on the carrier board. Utility Model Content
[0005] To address the shortcomings of existing technologies, the purpose of this invention is to provide a chip interface carrier board that simultaneously rotates the core board and the prepreg layer in opposite directions by the same angle, thereby improving the uniformity of the DK variation of the glass fiber and resin medium through which the trace passes, improving impedance fluctuations, and achieving ultra-long, high-speed traces that avoid the influence of glass fiber effects in a very high frequency range.
[0006] To achieve the above objectives, the present invention provides the following technical solution:
[0007] A chip interface carrier board for ultra-long, high-speed traces that avoids the effects of fiberglass, includes a copper foil layer, a core board layer, and a prepreg layer disposed between the copper foil layers. The core board layer is woven from core board warp and weft yarn layers, and the prepreg layer is woven from prepreg warp and weft yarn layers. A copper-clad portion is provided between the core board layer and the prepreg layer. The core board rotation angle between the corresponding trace direction of the core board layer and the axis of the copper-clad portion is opposite to the prepreg rotation angle between the corresponding trace direction of the prepreg layer and the axis of the copper-clad portion.
[0008] The present invention is further configured such that the warp layer and the weft layer of the core board are perpendicular to each other, and the warp layer and the weft layer of the semi-cured sheet are perpendicular to each other.
[0009] The present invention is further configured such that the copper-clad portion is aligned with the routing direction of the substrate.
[0010] The present invention is further configured such that: the core board rotation angle is formed by rotating the core board weft layer along the copper-clad part axis, and the prepreg rotation angle is formed by rotating the prepreg weft layer along the copper-clad part axis.
[0011] By adopting the above technical solution, the core board rotation angle is the rotation angle between the core board weft layer and the copper-clad part axis, and the prepreg rotation angle is the rotation angle between the prepreg weft layer and the copper-clad part axis. The core board rotation angle between the core board layer and the copper-clad part and the prepreg rotation angle between the prepreg layer and the copper-clad part are opposite to each other, that is, the rotation angles of the core board layer and the prepreg layer relative to the routing direction are opposite.
[0012] The present invention is further configured such that: the warp layer and the weft layer of the core board are made of flat fiberglass cloth, and the upper and lower surfaces of the warp layer and the weft layer of the core board are covered with resin.
[0013] The present invention is further configured such that the warp layer and weft layer of the core board contain glass fibers.
[0014] The present invention is further configured such that: the warp layer and the weft layer of the semi-cured sheet are made of flat fiberglass cloth, and the upper and lower surfaces of the warp layer and the weft layer of the semi-cured sheet are covered with resin.
[0015] The present invention is further configured such that the warp layer and the weft layer of the semi-cured sheet contain glass fibers.
[0016] The beneficial effects of this utility model are:
[0017] By simultaneously rotating the core layer (formed by the warp and weft layers of the core board) and the prepreg layer (formed by the warp and weft layers of the prepreg) in opposite directions by the same angle, the resonant point of the chip interface carrier board can be effectively improved in higher frequency environments while maintaining the same material utilization rate. This reduces the resonance caused by the glass fiber effect due to the cumulative line length, improves the uniformity of the DK variation of the glass fiber and resin medium through which the traces pass, improves impedance fluctuation, and avoids the influence of the glass fiber effect in the high frequency range. Attached Figure Description
[0018] The present invention will be further described below with reference to the accompanying drawings and embodiments.
[0019] Figure 1 This is a warp and weft weaving diagram showing how to reduce the fiberglass effect by simultaneously rotating the angles of PP and core boards in a conventional manner.
[0020] Figure 2 for Figure 1 The diagram shows a cross-sectional view of reducing the glass fiber effect by simultaneously rotating the angles of the PP and core sheets using the conventional method.
[0021] Figure 3 This is a graph showing the measured insertion loss curves for different angles of a traditional board material with a rotating wiring method.
[0022] Figure 4 This is a wiring diagram of the chip interface carrier board of this utility model.
[0023] Figure 5 for Figure 4 The diagram shows the wiring within the core board layer.
[0024] Figure 6 for Figure 4 The diagram shows the wiring within the prepreg layer.
[0025] Figure 7 To compare the insertion loss curves and return loss curves of conventional rotation and this invention using the same PP and core sheets.
[0026] Figure labeling: 10, copper foil layer;
[0027] 20. Core board layer; 21. Core board warp layer; 22. Core board weft layer; 23. Core board rotation angle;
[0028] 30. Prepreg layer; 31. Prepreg warp layer; 32. Prepreg weft layer; 33. Prepreg rotation angle;
[0029] 40. Resin; 50. Glass fiber; 60. Copper cladding. Detailed Implementation
[0030] To make the technical problem to be solved, the technical solution, and the beneficial effects of this utility model clearer, the present utility model will now be described in detail with reference to the accompanying drawings. This drawing is a simplified schematic diagram, illustrating only the basic aspects of the present utility model, and therefore only shows the components relevant to the present utility model. Obviously, the described embodiments are only some, not all, of the embodiments of this utility model. All other embodiments obtained by those skilled in the art based on the embodiments of this utility model without creative effort are within the scope of protection of this utility model.
[0031] Please refer to Figure 1 and Figure 2Existing technologies use a special warp and weft weaving method to create a special warp and weft structure in fiberglass cloth, which can improve the fiberglass effect to some extent. However, in carrier substrate materials, fiberglass typically has a higher dielectric constant (DK), while resin typically has a lower DK. The difference between the DK of fiberglass and resin, coupled with the influence of the length of ultra-long high-speed signal lines on the chip interface carrier, makes the cumulative effect of the fiberglass effect difficult to eliminate. A common method to further reduce the fiberglass effect is to simultaneously rotate the angles of the PP (core board) and core (prepreg) substrates, such as... Figure 1 As shown, when the angles of the PP (core board) and core (prepreg) sheets are rotated simultaneously, the warp and weft threads of the glass fibers within the PP (core board) and core (prepreg) sheets all form acute angles. When the differential signal traces are at an angle (not parallel or perpendicular) to the warp and weft threads of the glass fiber cloth within the upper and lower dielectric materials (resin), the dielectric environment (DK) traversed by the P and N pairs of the differential pair is essentially the same. Therefore, by rotating the angles of the PP (core board) and core (prepreg) sheets, the impedance change period of the high-speed signal line passing through the glass fiber cloth can be changed, thereby altering the resonant point position of the insertion loss curve to ensure that the resonant frequency is above the high-speed signal reference frequency. This shifts the resonant frequency of the insertion loss curve caused by the glass fiber effect to a higher frequency, thus offsetting the high-speed signal frequency range. However, this method also leads to reduced material utilization and increased costs.
[0032] like Figure 3 As shown, the insertion loss curves for traditional board trace rotation and fiberglass traces at different angles are plotted, with the horizontal axis representing frequency and the vertical axis representing signal insertion loss. Referring to the insertion loss curves, the coordinates of the insertion loss resonant point when the board trace rotation angle is 5 degrees and the wiring length is 4 inches are (14.1500, -4.2456); when the board trace rotation angle is 7 degrees and the wiring length is 4 inches, the coordinates are (21.7100, -5.9316); when the board trace rotation angle is 10 degrees and the wiring length is 4 inches, the coordinates are (33.0500, -8.2002); when the board trace rotation angle is 15 degrees and the wiring length is 4 inches, the coordinates are (52.4400, -12.4611); and when the board trace rotation angle is 10 degrees and the wiring length is 8 inches, the coordinates are (33.1900, -16.8320). Therefore, it can be seen that as the differential trace angle increases, its insertion loss resonant frequency also gradually increases; at the same angle, as the trace length increases, its resonance depth also increases. However, the larger the rotation angle of the board, the lower the board utilization rate, and the greater the corresponding cost increase. To meet the higher frequency requirements of the chip interface carrier board when using ultra-long high-speed signal lines, it is necessary to further improve the insertion loss resonant point of the chip interface carrier board based on existing technology.
[0033] Please refer to Figure 4-6 This utility model discloses a chip interface carrier board for ultra-long, high-speed traces that avoids the influence of fiberglass effect. It includes a copper foil layer 10, a core board layer 20, and a prepreg layer 30 disposed between the copper foil layers 10. A copper-clad portion 60 is provided between the core board layer 20 and the prepreg layer 30, and the copper-clad portion 60 is aligned with the trace direction of the board. The core board layer 20 is woven from core board warp yarn layers 21 and core board weft yarn layers 22, and the prepreg layer 30 is woven from prepreg warp yarn layers 31 and prepreg weft yarn layers 32. The core board warp yarn layers 21 and core board weft yarn layers 22 are perpendicular to each other, and the prepreg warp yarn layers 31 and prepreg weft yarn layers 32 are also perpendicular to each other.
[0034] Please refer to Figure 4-6 The core board warp layer 21 and core board weft layer 22 are made of flat fiberglass cloth, and both the upper and lower surfaces of the core board warp layer 21 and core board weft layer 22 are covered with resin 40. The prepreg warp layer 31 and prepreg weft layer 32 are made of flat fiberglass cloth, and both the upper and lower surfaces of the prepreg warp layer 31 and prepreg weft layer 32 are covered with resin 40. Preferably, the core board warp layer 21 and core board weft layer 22 can be made of 1078 flat fiberglass cloth, and the prepreg warp layer 31 and prepreg weft layer 32 can be made of 1035 flat fiberglass cloth. The core board warp layer 21 and core board weft layer 22 contain glass fibers 50, and the prepreg warp layer 31 and prepreg weft layer 32 contain glass fibers 50.
[0035] Please refer to Figure 4-6 The core board rotation angle 23 between the corresponding routing direction of the core board layer 20 and the axis of the copper-clad part 60 (corresponding to) Figure 5 The prepreg rotation angle 33 (corresponding to the direction of the prepreg layer 30 and the axis of the copper-clad portion 60) between the prepreg layer 30 and the corresponding trace direction is α). Figure 6 The rotation angles β and β are opposite, meaning the rotation angles of the core layer 20 and the prepreg layer 30 relative to the routing direction are opposite. The core rotation angle 23 is formed by rotating the core warp layer 21 or the core weft layer 22 along the axis of the copper-clad portion 60. In other words, the core rotation angle 23 is the rotation angle between the core warp layer 21 or the core weft layer 22 and the axis of the copper-clad portion 60. Figure 5 As shown in the diagram, α is formed by rotating the core board weft layer 22 along the axis of the copper-clad portion 60. The prepreg rotation angle 33 is formed by rotating the prepreg warp layer 31 or the prepreg weft layer 32 along the axis of the copper-clad portion 60. In other words, the prepreg rotation angle 33 is the rotation angle between the prepreg warp layer 31 or the prepreg weft layer 32 and the axis of the copper-clad portion 60. Figure 5 (As shown in the figure, β is formed by rotating the semi-cured sheet weft layer 32 along the axis of the copper-clad portion 60).
[0036] It should be noted that the corresponding routing direction of the core board layer 20 is the direction of the core board warp layer 21 or the core board weft layer 22 on the core board layer 20, and the corresponding routing direction of the semi-cured sheet layer 30 is the direction of the semi-cured sheet warp layer 31 or the semi-cured sheet weft layer 32 on the semi-cured sheet layer 30. When the routing direction of the core board layer 20 is the direction of the core board warp layer 21, the routing direction of the semi-cured sheet layer 30 is the direction of the semi-cured sheet warp layer 31; when the routing direction of the core board layer 20 is the direction of the core board weft layer 22, the routing direction of the semi-cured sheet layer 30 is the direction of the semi-cured sheet weft layer 32. In this embodiment, the rotation angles 23 of the core board and 33 of the semi-cured sheet can be 5 degrees, 7 degrees, 10 degrees, or 15 degrees. Preferably, when the rotation angle 23 of the core board and the rotation angle 33 of the prepreg are 10 degrees, the high-speed differential pair impedance between the core board layer 20 and the prepreg layer 30 is 90 ohms, and the differential pair linewidth / spacing is 3.5 mil / 11.5 mil.
[0037] like Figure 7 As shown, using the same PP (core board) and core (prepreg) boards, the conventional rotation scheme and the rotation scheme of this invention are compared. Modeling and simulation are performed to obtain insertion loss curves and return loss curves. The horizontal axis represents frequency, and the vertical axis represents decibels. In the figure, the insertion loss curve is located above the return loss curve. Specifically, the S2inch-5deg-1, 2inch-5deg-1 curve corresponds to a wiring length of 2 inches and a board trace rotation angle of 5 degrees for the return loss curve; the S2inch-5deg-2, 2inch-5deg-1 curve corresponds to a wiring length of 2 inches and a board trace rotation angle of 5 degrees for the insertion loss curve; the S2inch-7deg-1, 2inch-7deg-1 curve corresponds to a wiring length of 2 inches and a board trace rotation angle of 7 degrees for the return loss curve; the S2inch-7deg-2, 2inch-7deg-1 curve corresponds to a wiring length of 2 inches and a board trace rotation angle of 7 degrees for the insertion loss curve; S2inc The h-10deg-1, 2inch-10deg-1 curve corresponds to a return loss curve for a 2-inch wiring length and a board trace rotation angle of 10 degrees. The S2inch-10deg-2, 2inch-10deg-1 curve corresponds to an insertion loss curve for a 2-inch wiring length and a board trace rotation angle of 10 degrees. The S2inch-10deg-1, 2inch-10deg-1 curve corresponds to a return loss curve for a 2-inch wiring length and a board trace rotation angle of 10 degrees in the opposite direction. The S2inch-10deg-2, 2inch-10deg-1 curve corresponds to an insertion loss curve for a 2-inch wiring length and a board trace rotation angle of 10 degrees in the opposite direction.
[0038] Referring to the return loss curves for different rotation angles, the coordinates of the return loss resonant point are as follows: for a 2-inch trace length and a simultaneous rotation angle of 5 degrees, the coordinates are (18.49608, -15.64701); for a 2-inch trace length and a simultaneous rotation angle of 7 degrees, the coordinates are (25.35435, -11.89953); for a 2-inch trace length and a simultaneous rotation angle of 10 degrees, the coordinates are (35.76, -13.05107); and for a 2-inch trace length and a reverse rotation angle of 10 degrees, the coordinates are (53.28, -12.72349). Therefore, it can be concluded that when the core layer 20 and the prepreg layer 30 are rotated simultaneously by 10°, the resonant point of the long-distance trace appears at approximately 33 GHz. Conversely, when the core layer 20 and the prepreg layer 30 are rotated 10° in opposite directions, the resonant point of the long-distance differential trace is approximately at 53 GHz. In both methods, the rotation angle of the core board layer 20 and the semi-cured sheet layer 30 is 10°. With the same material utilization rate, the core board layer 20 and the semi-cured sheet layer 30 rotate in opposite directions to reach higher resonance points, which can meet the performance requirements at higher frequencies.
[0039] By simultaneously rotating the core board layer 20, formed by weaving the core board warp layer 21 and the core board weft layer 22, and the semi-cured sheet layer 30, formed by weaving the semi-cured sheet warp layer 31 and the semi-cured sheet weft layer 32, in opposite directions by the same angle, the resonant point of the chip interface carrier board material can be effectively improved in higher frequency operating environments while maintaining the same material utilization rate. This reduces the resonance caused by the glass fiber effect due to the cumulative line length, improves the uniformity of the change in DK of the glass fiber and resin medium through which the traces pass, improves impedance fluctuation, and avoids the influence of the glass fiber effect in the high frequency range.
[0040] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.
[0041] It should be understood that the terms "length", "width", "up", "down", "front and back", "left and right", "vertical", "horizontal", "top", "bottom", "inner", and "outer" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.
[0042] Based on the preferred embodiments of this utility model described above, those skilled in the art can make various changes and modifications without departing from the scope of this utility model. The technical scope of this utility model is not limited to the contents of the specification, but must be determined according to the scope of the claims.
Claims
1. A chip interface carrier board for ultra-long, high-speed traces to avoid the effects of fiberglass, characterized in that: The system includes a copper foil layer (10) and a core board layer (20) and a prepreg layer (30) disposed between the copper foil layer (10). The core board layer (20) is woven from a core board warp layer (21) and a core board weft layer (22). The prepreg layer (30) is woven from a prepreg warp layer (31) and a prepreg weft layer (32). A copper-clad portion (60) is provided between the core board layer (20) and the prepreg layer (30). The core board rotation angle (23) between the corresponding routing direction of the core board layer (20) and the axis of the copper-clad portion (60) is opposite to the prepreg rotation angle (33) between the corresponding routing direction of the prepreg layer (30) and the axis of the copper-clad portion (60).
2. The chip interface carrier board for avoiding the influence of glass fiber effect on ultra-long high-speed traces according to claim 1, characterized in that: The core board warp layer (21) and core board weft layer (22) are perpendicular to each other, and the semi-cured sheet warp layer (31) and semi-cured sheet weft layer (32) are perpendicular to each other.
3. The chip interface carrier board for avoiding the influence of glass fiber effect on ultra-long high-speed traces according to claim 1, characterized in that: The copper-clad portion (60) is aligned with the routing direction of the substrate.
4. The chip interface carrier board for avoiding the influence of glass fiber effect on ultra-long high-speed traces according to claim 3, characterized in that: The core board rotation angle (23) is formed by rotating the core board weft layer (22) along the copper-clad part (60) axis, and the prepreg rotation angle (33) is formed by rotating the prepreg weft layer (32) along the copper-clad part (60) axis.
5. A chip interface carrier board for avoiding the influence of glass fiber effect on ultra-long high-speed traces according to claim 1, characterized in that: The core board warp layer (21) and core board weft layer (22) are made of flat fiberglass cloth, and the upper and lower surfaces of the core board warp layer (21) and core board weft layer (22) are covered with resin (40).
6. The chip interface carrier board for avoiding the influence of glass fiber effect on ultra-long high-speed traces according to claim 5, characterized in that: The core board warp layer (21) and core board weft layer (22) contain glass fibers (50).
7. The chip interface carrier board for avoiding the influence of glass fiber effect on ultra-long high-speed traces according to claim 1, characterized in that: The warp layer (31) and weft layer (32) of the semi-cured sheet are made of flat fiberglass cloth, and the upper and lower surfaces of the warp layer (31) and weft layer (32) of the semi-cured sheet are covered with resin (40).
8. A chip interface carrier board for avoiding the influence of glass fiber effect on ultra-long high-speed traces according to claim 7, characterized in that: The semi-cured sheet warp layer (31) and semi-cured sheet weft layer (32) contain glass fibers (50).