A finger section difference control lamination structure of a PCB

Abstract

The application discloses a PCB finger section difference control laminated structure and relates to the technical field of PCBs. The upper heat pressing plate assembly is provided with an upper buffer pressure equalizing pad on the lower side, and the lower surface of the upper buffer pressure equalizing pad is provided with an upper mirror surface steel plate; and the upper outer copper foil is arranged on the lower surface of the upper mirror surface steel plate. The PCB finger section difference control laminated structure is provided with an auxiliary groove with a height matching the height of the gold finger protrusion on the middle part of the pp prepreg of the core plate assembly, corresponding to the position of the gold finger on the inner layer core plate, and the auxiliary groove adopts a 10°-30° inclined gradual change structure with a smooth edge transition. Through the above design, stress concentration of the gold finger area caused by uneven extrusion of the pp prepreg during the laminating process can be effectively avoided, the protrusion or depression of the gold finger caused by force imbalance can be prevented, the protrusion height of the gold finger can be accurately matched, and a solid structural foundation for section difference control is laid.

Description

Technical Field

[0001] This invention relates to the field of PCB board technology, specifically to a lamination structure for controlling the finger segmentation of a PCB board. Background Technology

[0002] With the rapid development of electronic products towards higher density and higher performance, 6-8 layer PCBs are widely used in communications, consumer electronics and other fields due to their excellent signal transmission performance and space utilization. ACF (Anisotropic Conductive Adhesive Film) bonding process is the core process for connecting PCBs to components such as chips and display modules, and its connection reliability directly determines the quality of the end product.

[0003] However, in the current manufacturing of 6-8 layer PCBs, the step difference problem of the fingers (gold fingers) in the ACF bonding area is becoming increasingly prominent, becoming a key bottleneck restricting product yield. Traditional multilayer board lamination, gold plating and other processes easily lead to uneven thickness in the finger area, and step differences are common. Excessive step differences will cause uneven distribution of ACF conductive particles, which in turn will cause problems such as poor contact and impedance fluctuations, affecting product stability. Current improvement methods such as chemical polishing and laser adjustment have the disadvantages of high cost or low production efficiency, and cannot meet the needs of large-scale production.

[0004] Therefore, in view of this, we studied and improved the existing structure and its shortcomings, and proposed a lamination structure for controlling the finger segment difference of PCB board. Summary of the Invention

[0005] To address the shortcomings of existing technologies, this invention provides a lamination structure for controlling the finger segmentation of PCB boards, thus solving the problems mentioned in the background section.

[0006] To achieve the above objectives, the present invention provides the following technical solution: a lamination structure for controlling the finger step difference of a PCB board, comprising an upper hot press plate assembly and an upper outer copper foil. An upper buffer pressure equalizing pad is installed on the lower side of the upper hot press plate assembly, and an upper mirror steel plate is provided on the lower surface of the upper buffer pressure equalizing pad. The upper outer copper foil is disposed on the lower surface of the upper mirror steel plate. A core board assembly for controlling the finger step difference is installed on the lower surface of the upper outer copper foil. The core board assembly includes an outer core board one, a PP prepreg two, gold fingers, an inner core board, a PP prepreg three, and an outer core board two. The lower surface of the outer core board one is provided with PP prepreg two, and an auxiliary groove is formed in the middle of the PP prepreg two. An inner core board is installed on the lower surface of the PP prepreg two, and PP prepreg three is disposed on the lower surface of the inner core board. The lower surface of the PP prepreg three is provided with the outer core board two.

[0007] Furthermore, the lower surface of the outer core board 2 is provided with PP prepreg 4, and the lower surface of the PP prepreg 4 is fitted with a lower outer copper foil.

[0008] Furthermore, a lower mirror steel plate is provided on the lower surface of the lower outer copper foil, and a lower hot press plate assembly is installed on the lower surface of the lower mirror steel plate. The upper mirror steel plate and the lower mirror steel plate have the same structure.

[0009] Furthermore, the upper hot press plate assembly and the lower hot press plate assembly have the same structure, and the upper hot press plate assembly includes a back plate, a threaded column, a hot press inner plate and a hot press plate. The threaded column is installed on the internal thread of the back plate, and the hot press inner plate is provided at the bottom of the threaded column. The hot press plate is slidably installed on the outside of the hot press inner plate.

[0010] Furthermore, the hot press plate has a hot oil channel one and a hot oil channel two inside, and the hot oil channel one and the hot oil channel two are connected.

[0011] Furthermore, the auxiliary groove in the middle of the second PP prepreg material corresponds one-to-one with the position of the gold fingers on the inner core board, and the depth of the auxiliary groove is adapted to the protrusion height of the gold fingers.

[0012] Furthermore, the auxiliary groove is a gradient groove structure with smooth edge transition, and the edge of the auxiliary groove has an inclined transition surface of 10°-30° with the surface of the PP prepreg.

[0013] Furthermore, PP prepreg one and PP prepreg four are symmetrically arranged on the upper and lower sides of the core board assembly, and the type, thickness and flowability of PP prepreg one and PP prepreg four are completely identical.

[0014] Furthermore, both the upper and lower buffer pressure equalizing pads are made of high-density, low-compression-permanent-deformation material, and the thickness error between the upper and lower buffer pressure equalizing pads is no greater than 0.1 mm.

[0015] Furthermore, the hot-pressing inner plate is provided corresponding to the gold finger area, and the hot-pressing inner plate is located in the middle of the hot-pressing plate.

[0016] This invention provides a lamination structure for controlling the finger segment difference of a PCB board, which has the following beneficial effects: 1. The lamination structure for controlling the step difference of the PCB board has an auxiliary groove in the middle of the PP prepreg of the core board assembly, corresponding to the position of the gold fingers on the inner core board. The auxiliary groove adopts a 10°-30° inclined gradient structure with smooth edge transition. This design can effectively avoid stress concentration in the gold finger area caused by uneven extrusion of PP prepreg during the lamination process, prevent the gold fingers from bulging or sinking due to unbalanced force, and accurately match the protrusion height of the gold fingers, laying a solid structural foundation for step difference control, ensuring the initial assembly alignment accuracy of the gold finger area, reducing step difference deviations in subsequent lamination processes, and improving the structural regularity of the PCB board gold fingers.

[0017] 2. The lamination structure for controlling the finger segment difference of this PCB board features identical upper and lower hot press plate assemblies. The position of the inner hot press plate can be adjusted via threaded posts on the back plate. The inner hot press plate is positioned corresponding to the gold finger area, and its extension height can be individually fine-tuned to achieve local pressure compensation for the gold finger area. This specifically addresses the pressure deviation caused by uneven thickness in the gold finger area. Simultaneously, the hot oil channels one and two inside the hot press plate are interconnected, and the circulating hot oil ensures uniform temperature distribution on the surface of the hot press plate, providing a stable temperature environment for lamination. Combined with the upper and lower buffer pressure equalizing pads made of high-density, low-compression permanent deformation material, the pressure can be buffered and evenly applied to the PCB board surface, avoiding uneven board thickness caused by local pressure imbalance and further reducing the gold finger segment difference.

[0018] 3. The lamination structure for controlling the finger step difference of this PCB board features symmetrically arranged PP prepreg 1 and PP prepreg 4 on the upper and lower sides of the core board assembly. The PP prepreg 1 and PP prepreg 4 are completely identical in type, thickness and flowability. This can effectively balance the interlayer stress on the upper and lower sides of the core board assembly, avoid PCB board deformation caused by stress imbalance during lamination, and thus prevent the gold fingers from having step differences due to board deformation. At the same time, the upper and lower mirror steel plates have the same structure, which can ensure the flatness of the upper and lower surfaces of the PCB board after lamination is consistent, further improving the surface flatness of the gold finger area. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the overall structure of a lamination structure for controlling the finger step difference of a PCB board according to the present invention. Figure 2 This is a schematic diagram of the core board assembly structure of the laminate structure for controlling the finger step difference of a PCB board according to the present invention; Figure 3 This is a schematic diagram of a hot press plate structure for a lamination structure of PCB board finger step difference control according to the present invention; Figure 4 This is a schematic diagram of the secondary structure of PP prepreg for PCB board finger step difference control laminate structure according to the present invention; Figure 5 This is a schematic diagram of the upper hot press plate assembly structure of the lamination structure for controlling the finger step difference of a PCB board according to the present invention; Figure 6 This is a perspective view of the hot press plate structure of the lamination structure for controlling the finger segment difference of a PCB board according to the present invention.

[0020] In the diagram: 1. Upper hot press plate assembly; 101. Back plate; 102. Threaded column; 103. Hot press inner plate; 104. Hot press plate; 2. Upper buffer pressure equalizing pad; 3. Upper mirror steel plate; 4. Upper outer copper foil; 5. PP prepreg one; 6. Core board assembly; 601. Outer core board one; 602. PP prepreg two; 603. Gold finger; 604. Inner core board; 605. PP prepreg three; 606. Outer core board two; 7. PP prepreg four; 8. Lower outer copper foil; 9. Lower mirror steel plate; 10. Lower buffer pressure equalizing pad; 11. Lower hot press plate assembly; 12. Auxiliary groove; 13. Hot oil channel one; 14. Hot oil channel two. Detailed Implementation

[0021] The embodiments of the present invention will be described in further detail below with reference to the accompanying drawings and examples. The following examples are for illustrative purposes only and should not be construed as limiting the scope of the invention.

[0022] like Figures 1-5As shown, the present invention provides a technical solution: a lamination structure for controlling the finger step difference of a PCB board, including an upper hot press plate assembly 1, a back plate 101, threaded pillars 102, a hot press inner plate 103, a hot press plate 104, an upper buffer pressure equalizing pad 2, an upper mirror steel plate 3, an upper outer copper foil 4, PP prepreg 1 5, a core board assembly 6, an outer core board 1 601, PP prepreg 2 602, gold fingers 603, an inner core board 604, PP prepreg 3 605, an outer core board 2 606, PP prepreg 4 7, a lower outer copper foil 8, a lower mirror steel plate 9, a lower buffer pressure equalizing pad 10, a lower hot press plate assembly 11, an auxiliary groove 12, a hot oil channel 13 and a hot oil channel 2 14, wherein an upper buffer pressure equalizing pad 2 is installed on the lower side of the upper hot press plate assembly 1, and the upper buffer pressure equalizing pad The lower surface of component 2 is provided with an upper mirror steel plate 3, and an upper outer copper foil 4 is provided on the lower surface of the upper mirror steel plate 3. A core board assembly 6 for finger step difference control is installed on the lower surface of the upper outer copper foil 4. The core board assembly 6 includes an outer core board 601, a PP prepreg 602, a gold finger 603, an inner core board 604, a PP prepreg 605, and an outer core board 606. The lower surface of the outer core board 601 is provided with the PP prepreg 602, and an auxiliary groove 12 is opened in the middle of the PP prepreg 602. The lower surface of the PP prepreg 602 is provided with the inner core board 604, and the lower surface of the inner core board 604 is provided with the PP prepreg 605. The auxiliary groove 12 opened in the middle of the PP prepreg 602 is connected to the inner core board 604. The gold fingers 603 are positioned one-to-one, and the depth of the auxiliary groove 12 matches the protrusion height of the gold fingers 603. The auxiliary groove 12 is a gradient groove structure with a smooth edge transition, and the edge of the auxiliary groove 12 is inclined at 10°-30° to the surface of the PP prepreg 602. The lower surface of the outer core plate 606 is provided with PP prepreg 7, and the lower surface of the PP prepreg 7 is installed with the lower outer copper foil 8. The lower surface of the lower outer copper foil 8 is provided with the lower mirror steel plate 9, and the lower surface of the lower mirror steel plate 9 is installed with the lower hot press plate assembly 11. The upper mirror steel plate 3 and the lower mirror steel plate 9 have the same structure. The lower surface of the PP prepreg 605 is provided with the outer core plate 606, and the upper and lower sides of the core plate assembly 6 are symmetrically provided with PP prepreg 7. Prepreg 1 (5) and PP prepreg 4 (7) are assembled in the following order from top to bottom: upper hot press plate assembly 1, upper buffer pressure equalizing pad 2, upper mirror steel plate 3, upper outer copper foil 4, PP prepreg 1 (5), core board assembly 6, PP prepreg 4 (7), lower outer copper foil 8, lower mirror steel plate 9, lower buffer pressure equalizing pad 10, and lower hot press plate assembly 11. The core board assembly 6 must be assembled strictly in the following order: outer core board 1 (601), PP prepreg 2 (602), inner core board 604, PP prepreg 3 (605), and outer core board 2 (606). This ensures that the auxiliary groove 12 in the middle of PP prepreg 2 (602) corresponds one-to-one with the gold fingers 603 on the inner core board 604.Furthermore, the depth of the auxiliary groove 12 is adapted to the height of the gold finger 603 protrusion. This auxiliary groove 12 adopts a 10°-30° inclined gradient structure with smooth edge transition, effectively preventing stress concentration in the gold finger 603 area due to uneven extrusion of the PP prepreg during lamination. Structurally, this lays the foundation for step difference control. The PP prepreg 5 and PP prepreg 7, symmetrically arranged on the upper and lower sides of the core board assembly 6, have identical models, thicknesses, and flow properties. This balances the interlayer stress on the upper and lower sides of the core board assembly 6, preventing PCB board deformation and gold finger 603 step differences caused by stress imbalance during lamination. The upper mirror steel plate 3 and lower mirror steel plate 9 have the same structure, ensuring consistent flatness of the upper and lower surfaces of the PCB board after lamination, further improving the flatness of the gold finger 603 area.

[0023] like Figure 1 , Figure 5 and Figure 6 As shown, both the upper buffer pressure equalizing pad 2 and the lower buffer pressure equalizing pad 10 are made of high-density, low-compression-permanent-deformation material, and the thickness error between the upper buffer pressure equalizing pad 2 and the lower buffer pressure equalizing pad 10 is no greater than 0.1 mm. The hot-pressing inner plate 103 is set corresponding to the gold finger 603 area, and the hot-pressing inner plate 103 is located in the middle of the hot-pressing plate 104. The upper hot-pressing plate assembly 1 and the lower hot-pressing plate assembly 11 work synchronously, and their structures are completely identical. The position of the hot-pressing inner plate 103 is adjusted by the threaded post 102 on the back plate 101. The hot-pressing inner plate 103 is set corresponding to the gold finger 603 area and is located in the middle of the hot-pressing plate 104. The extension height of the hot-pressing inner plate 103 can be finely adjusted by rotating the threaded post 102 to achieve the adjustment of the gold finger 603 area. The local pressure compensation in the finger 603 area specifically addresses the pressure deviation caused by uneven thickness in the gold finger 603 area, further reducing the step difference. During the lamination process, the hot oil channel 13 and hot oil channel 14 inside the hot press plate 104 are connected, and the hot oil circulates in the channel to ensure uniform temperature distribution on the surface of the hot press plate 104, providing a stable temperature environment for lamination. At the same time, the upper buffer pressure equalizing pad 2 and the lower buffer pressure equalizing pad 10 are made of high-density, low-compression permanent deformation material, and their thickness error is no more than 0.1mm. This can effectively buffer the pressure transmitted by the hot press plate assembly, so that the pressure is evenly applied to the entire PCB board surface, avoiding uneven board thickness caused by excessive or insufficient local pressure.

[0024] In summary, as Figures 1-6As shown, the PCB board uses a finger-segment control laminate structure. During use, the entire laminate structure is assembled in the following order from top to bottom: upper hot press plate assembly 1, upper buffer pressure equalizing pad 2, upper mirror steel plate 3, upper outer copper foil 4, PP prepreg 1 5, core board assembly 6, PP prepreg 4 7, lower outer copper foil 8, lower mirror steel plate 9, lower buffer pressure equalizing pad 10, and lower hot press plate assembly 11. The core board assembly 6 must be assembled strictly in the following order: outer core board 1 601, PP prepreg 2 602, inner core board 604, PP prepreg 3 605, and outer core board 2 606. This ensures that the auxiliary groove 12 in the middle of PP prepreg 2 602 aligns with... The gold fingers 603 on the inner core board 604 are aligned one-to-one, and the depth of the auxiliary groove 12 is adapted to the protrusion height of the gold fingers 603. The auxiliary groove 12 adopts a 10°-30° inclined gradient structure with smooth edge transition, which can effectively avoid stress concentration in the gold finger 603 area due to uneven extrusion of PP prepreg during lamination. Structurally, it lays the foundation for step difference control. After assembly, the lamination equipment is started, and the upper hot press plate assembly 1 and the lower hot press plate assembly 11 work synchronously. The two have completely identical structures and both adjust the position of the hot press inner plate 103 through the threaded post 102 on the back plate 101. The hot press inner plate 103 is set in the area corresponding to the gold fingers 603 and is located in the hot press area. In the middle of plate 104, the extension height of the inner hot-press plate 103 can be finely adjusted by rotating the threaded column 102, achieving local pressure compensation in the gold finger 603 area. This specifically addresses the pressure deviation caused by uneven thickness in the gold finger 603 area, further reducing step differences. During lamination, the hot oil channel 13 and hot oil channel 14 inside the hot-press plate 104 are interconnected, allowing hot oil to circulate within the channels. This ensures uniform surface temperature distribution on the hot-press plate 104, providing a stable temperature environment for lamination. Simultaneously, the upper buffer pressure equalizing pad 2 and the lower buffer pressure equalizing pad 10 are made of high-density, low-compression permanent deformation material, with a thickness error of no more than 0.1 mm, effectively mitigating pressure distribution. The pressure transmitted by the hot press plate assembly ensures that the pressure is applied evenly to the entire PCB board surface, avoiding uneven board thickness caused by excessive or insufficient local pressure. In addition, the PP prepreg 1 5 and PP prepreg 4 7 symmetrically arranged on the upper and lower sides of the core board assembly 6 have the same model, thickness and flowability, which can balance the interlayer stress on the upper and lower sides of the core board assembly 6 and avoid PCB board deformation and gold finger 603 step difference caused by stress imbalance during lamination. The upper mirror steel plate 3 and lower mirror steel plate 9 have the same structure, which can ensure the flatness of the upper and lower surfaces of the PCB board after lamination, further improving the flatness of the gold finger 603 area, and finally achieving precise control of the gold finger 603 step difference.

[0025] The embodiments of the present invention are given for illustrative and descriptive purposes only, and are not intended to be exhaustive or to limit the invention to the forms disclosed. Many modifications and variations will be apparent to those skilled in the art. The embodiments were chosen and described in order to better illustrate the principles and practical application of the invention, and to enable those skilled in the art to understand the invention and to design various embodiments with various modifications suitable for a particular purpose.

Claims

1. A lamination structure for controlling the finger step difference of a PCB board, comprising an upper hot press assembly (1) and an upper outer copper foil (4), characterized in that: An upper buffer pressure equalizing pad (2) is installed on the lower side of the upper hot press plate assembly (1), and an upper mirror steel plate (3) is provided on the lower surface of the upper buffer pressure equalizing pad (2). The upper outer copper foil (4) is provided on the lower surface of the upper mirror steel plate (3). A core board assembly (6) for finger step difference control is installed on the lower surface of the upper outer copper foil (4), and the core board assembly (6) includes an outer core board one (601), a PP prepreg two (602), a gold finger (603), an inner core board (604), and PP Prepreg 3 (605) and outer core board 2 (606), the lower surface of the outer core board 1 (601) is provided with PP prepreg 2 (602), and an auxiliary groove (12) is opened in the middle of the PP prepreg 2 (602). The lower surface of the PP prepreg 2 (602) is installed with an inner core board (604), and the lower surface of the inner core board (604) is provided with PP prepreg 3 (605). The lower surface of the PP prepreg 3 (605) is provided with outer core board 2 (606).

2. The lamination structure for controlling the finger step difference of a PCB board according to claim 1, characterized in that: The lower surface of the outer core board 2 (606) is provided with PP prepreg 4 (7), and the lower surface of the PP prepreg 4 (7) is provided with lower outer copper foil (8).

3. The lamination structure for controlling the finger step difference of a PCB board according to claim 2, characterized in that: The lower outer copper foil (8) is provided with a lower mirror steel plate (9), and a lower hot press plate assembly (11) is installed on the lower surface of the lower mirror steel plate (9). The upper mirror steel plate (3) and the lower mirror steel plate (9) have the same structure.

4. The lamination structure for controlling the finger step difference of a PCB board according to claim 1, characterized in that: The upper hot press plate assembly (1) and the lower hot press plate assembly (11) have the same structure. The upper hot press plate assembly (1) includes a back plate (101), a threaded post (102), a hot press inner plate (103), and a hot press plate (104). The threaded post (102) is installed on the internal thread of the back plate (101), and the hot press inner plate (103) is provided at the bottom of the threaded post (102). The hot press plate (104) is slidably installed on the outside of the hot press inner plate (103).

5. The lamination structure for controlling the finger step difference of a PCB board according to claim 4, characterized in that: The hot press plate (104) has a hot oil channel one (13) and a hot oil channel two (14) inside, and the hot oil channel one (13) and the hot oil channel two (14) are connected.

6. The lamination structure for controlling the finger step difference of a PCB board according to claim 1, characterized in that: The auxiliary groove (12) in the middle of the PP prepreg (602) corresponds one-to-one with the position of the gold finger (603) on the inner core board (604), and the depth of the auxiliary groove (12) is adapted to the protrusion height of the gold finger (603).

7. The lamination structure for controlling the finger step difference of a PCB board according to claim 1, characterized in that: The auxiliary groove (12) is a gradient groove structure with smooth edge transition, and the edge of the auxiliary groove (12) and the surface of the PP prepreg (602) are inclined transition surfaces of 10°-30°.

8. The lamination structure for controlling the finger step difference of a PCB board according to claim 1, characterized in that: The core board assembly (6) is symmetrically provided with PP prepreg one (5) and PP prepreg four (7) on its upper and lower sides, and the PP prepreg one (5) and PP prepreg four (7) have the same model, thickness and flowability.

9. The lamination structure for controlling the finger step difference of a PCB board according to claim 1, characterized in that: The upper buffer pressure equalizing pad (2) and the lower buffer pressure equalizing pad (10) are both made of high-density, low-compression permanent deformation material, and the thickness error of the upper buffer pressure equalizing pad (2) and the lower buffer pressure equalizing pad (10) is no greater than 0.1 mm.

10. The lamination structure for controlling the finger step difference of a PCB board according to claim 4, characterized in that: The hot-pressing inner plate (103) is provided in the area corresponding to the gold finger (603), and the hot-pressing inner plate (103) is located in the middle of the hot-pressing plate (104).

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