Semi-flex high interconnect printed circuit board and method of manufacturing the same

Abstract

The present application relates to a kind of semi-curved high interconnection printed circuit board and its manufacturing method, including first substrate, first prepreg, second substrate, second prepreg, third substrate, third prepreg, first copper foil, fourth prepreg, second copper foil and bending-resistant ink;First laser blind hole is provided in the first copper foil located in the uppermost layer and the third prepreg adjacent thereto, and first interconnection column is provided in the first laser blind hole;Second laser blind hole is provided in the second copper foil and the upper fourth prepreg, and second interconnection column is provided in the second laser blind hole;Through hole is provided between the upper surface of the first copper foil located in the uppermost layer and the lower surface of the second copper foil, and integral interconnection column is provided in the through hole.The present application realizes the manufacturing feasibility of semi-curved high interconnection printed circuit board, makes the semi-curved high interconnection printed circuit board manufactured to reach the ability of multifunctional integration, greatly extends the coverage of semi-curved high interconnection printed circuit board and the diversity of product function.

Description

Technical Field

[0001] This invention belongs to the field of printed circuit board technology, and specifically discloses a semi-curved high interconnect printed circuit board and its manufacturing method. Background Technology

[0002] With the diversification and lightweighting of electronic products, circuit boards require both flexibility and rigidity. Traditional circuit boards cannot meet these requirements. Therefore, semi-bending high interconnect printed circuit boards have been developed, which can meet the requirements of board bending while maintaining board rigidity, reducing board weight and improving performance reliability. Summary of the Invention

[0003] The purpose of this invention is to overcome the shortcomings of the prior art and provide a semi-curved high interconnect printed circuit board and a method for manufacturing the same.

[0004] According to the technical solution provided by the present invention, the semi-flexible high interconnect printed circuit board includes a first substrate, a first prepreg, a second substrate, a second prepreg, a third substrate, a third prepreg, a first copper foil, a fourth prepreg, a second copper foil, and a bend-resistant ink. A fourth prepreg is provided on the upper surface of the second copper foil, and a first substrate is provided on the upper surface of the fourth prepreg. The first substrate includes a first substrate, a first substrate upper copper foil located on the upper surface of the first substrate, and a first substrate lower copper foil located on the lower surface of the first substrate. A first prepreg is provided on the upper surface of the copper foil on the first substrate. One or more stacked second substrates are provided on the upper surface of the first prepreg. A first prepreg is provided between adjacent second substrates. The first substrate includes a second substrate, a second substrate upper copper foil located on the upper surface of the second substrate, and a second substrate lower copper foil located on the lower surface of the second substrate. A second prepreg is provided on the upper surface of the copper foil on the second substrate. One or more stacked third substrates are provided on the upper surface of the second prepreg. A second prepreg is provided between adjacent third substrates. The third substrate includes a third substrate, a third substrate upper copper foil located on the upper surface of the third substrate, and a third substrate lower copper foil located on the lower surface of the third substrate. A third prepreg is provided on the upper surface of the copper foil on the third substrate. One or more stacked first copper foils are provided on the upper surface of the third prepreg. A third prepreg is provided between adjacent first copper foils. Lines are etched on the second copper foil, the copper foil on the first substrate, the copper foil under the first substrate, the copper foil on the second substrate, the copper foil under the second substrate, the copper foil on the third substrate, the copper foil under the third substrate, and the first copper foil. A window groove is provided above the first substrate, so that the upper surface of the first substrate within the window groove is exposed, and a bend-resistant ink is provided on the lower surface of the second copper foil within the corresponding window groove. A first laser blind via is provided on the topmost first copper foil and the adjacent third prepreg, the first laser blind via penetrating the first copper foil and the third prepreg, so that the upper surface of the copper foil adjacent to the topmost first copper foil is exposed, and a first interconnect post is provided in the first laser blind via; a second laser blind via is provided on the second copper foil and the upper fourth prepreg, the second laser blind via penetrating the second copper foil and the fourth prepreg, so that the lower surface of the copper foil under the first substrate is exposed, and a second interconnect post is provided in the second laser blind via; A through hole is provided between the upper surface of the first copper foil and the lower surface of the second copper foil, and an integral interconnecting post is provided in the through hole.

[0005] Preferably, both the first interconnect post and the second interconnect post are frustum-shaped.

[0006] A method for manufacturing a semi-curved, highly interconnected printed circuit board, the method comprising the following steps: S1. A first substrate is provided, the first substrate including a first substrate, a first substrate upper copper foil located on the upper surface of the first substrate, and a first substrate lower copper foil located on the lower surface of the first substrate; S2. Etch lines on the copper foil on the first substrate and the copper foil under the first substrate, and simultaneously etch a window groove in the middle of the copper foil on the first substrate. The window groove penetrates the front end and rear end of the copper foil on the first substrate. Print a high-temperature resistant peelable wet film in the window groove. S3. Provide a first semi-cured sheet. Laser cutting is used to make slits on the first semi-cured sheet at the left and right lines of the window slot corresponding to S2. The slits penetrate the upper and lower surfaces of the first semi-cured sheet. A distance is left between the rear end of each slit and the rear end face of the first semi-cured sheet, and between the front end of each slit and the front end face of the first semi-cured sheet. S4. A second substrate is provided, the second substrate including a second substrate, a copper foil on the upper surface of the second substrate and a copper foil on the lower surface of the second substrate. Circuits are etched on the copper foil on the second substrate and the copper foil on the lower substrate. A slit is laser-cut on the copper foil on the second substrate at the left and right lines of the window slot corresponding to S2. The slit penetrates the copper foil on the second substrate and extends into the second substrate for a certain distance. The copper foil on the second substrate and the copper foil on the lower substrate at the left and right lines of the window slot corresponding to S2 are laser-cut. The slit penetrates the copper foil on the second substrate and extends into the second substrate for a certain distance. The second substrate is not cut through. S5. Provide a second pre-cured sheet; S6. A third substrate is provided, the third substrate including a third substrate, a copper foil on the upper surface of the third substrate and a copper foil on the lower surface of the third substrate, and circuits are etched on the copper foil on the upper surface of the third substrate and the copper foil on the lower surface of the third substrate. S7. Provide a third prepreg, a first copper foil, a fourth prepreg, and a second copper foil; S8. The second copper foil, the fourth prepreg, the first substrate, the first prepreg, at least one second substrate, the second prepreg, at least one third substrate, the third prepreg and the first copper foil are stacked together in a bottom-up order, such that the first prepreg is provided between adjacent second substrates and the second prepreg is provided between adjacent third substrates, and all materials are pressed together to form a press-fit stack. S9. Etch lines on the second copper foil and the first copper foil of the laminated plate; S10. The laminated plate, the third prepreg, and the first copper foil are stacked and pressed together in a bottom-up order. S11. Etch the circuit on the topmost copper foil; S12. Repeat steps S10 to S11 as required; S13. A first laser blind hole is drilled on the first copper foil located at the top layer. The first laser blind hole penetrates the first copper foil and the third prepreg, so that the upper surface of the copper foil adjacent to the first copper foil at the top layer is exposed. A second laser blind hole is drilled on the second copper foil. The second laser blind hole penetrates the second copper foil and the fourth prepreg, so that the lower surface of the copper foil under the first substrate is exposed. S14. Drill a through hole between the upper surface of the first copper foil and the lower surface of the second copper foil. S15. Copper is plated in the first laser blind hole and the second laser blind hole formed in S13 to form the first interconnect pillar and the second interconnect pillar respectively. Copper is plated on the hole wall of the through hole formed in S14 to form an integral interconnect pillar. S16. Lines are etched on the first copper foil and the second copper foil, and the first copper foil in the window slot area corresponding to S2 is etched away, so that the upper surface of the third prepreg is exposed. S17. Print flexural ink on the second copper foil at the window slot position corresponding to S2; S18. Print a first high-temperature resistant peelable ink on the area outside the window groove of S2 on the first copper foil, and print a second high-temperature resistant peelable ink on the area outside the bending resistant ink on the second copper foil. S19. Along the left and right lines of the window groove in S2, the third semi-cured sheet is grouted, and the grooving depth reaches below the upper surface of the bottom second semi-cured sheet. S20. Uncover the film to expose the high-temperature resistant peelable wet film, forming a deep groove at the uncovering point; S21. Remove the high-temperature resistant peelable wet film; S22. Remove the first high-temperature resistant peelable ink and the second high-temperature resistant peelable ink to obtain a semi-bent high interconnect printed circuit board.

[0007] Preferably, in S8, the number of first substrates is one, the number of second substrates is 1-5, and the number of third substrates is 1-5.

[0008] Preferably, in S12, steps S10 to S11 are repeated 0 to 4 times.

[0009] Preferably, in S13, both the first and second laser blind holes are frustum-shaped. The diameter of the larger end of the first laser blind hole is 0.1-0.15 mm and the diameter of the smaller end is 0.085-0.1 mm. The diameter of the larger end of the second laser blind hole is 0.1-0.15 mm and the diameter of the smaller end is 0.085-0.1 mm.

[0010] Preferably, in S14, the diameter of the through hole is 0.15-3 mm.

[0011] This invention enables the manufacturing feasibility of semi-bent high interconnect printed circuit boards, allowing the manufactured semi-bent high interconnect printed circuit boards to achieve multi-functional integration capabilities, greatly extending the coverage of semi-bent high interconnect printed circuit boards and the diversity of product functions. Attached Figure Description

[0012] Figure 1 This is a structural diagram of the first substrate provided in step S1 of Embodiment 1.

[0013] Figure 2 This is a structural diagram of the first substrate processed by step S2 of Example 1.

[0014] Figure 3 This is a structural diagram of the first semi-cured sheet provided and processed in step S3 of Example 1.

[0015] Figure 4 This is a structural diagram of the second substrate provided and processed in step S4 of Embodiment 1.

[0016] Figure 5 This is a structural diagram of the second semi-cured sheet provided in step S5 of Example 1.

[0017] Figure 6 This is a structural diagram of the third substrate provided and processed in step S6 of Embodiment 1.

[0018] Figure 7 This is a structural diagram of the press-fit plate obtained in step S8 of Example 1.

[0019] Figure 8 This is a structural diagram of the laminated plate after laser blind hole drilling in step S13 of Example 1.

[0020] Figure 9This is a structural diagram of the press-fit plate after drilling through holes in step S14 of Example 1.

[0021] Figure 10 This is a structural diagram of the laminated plate after copper filling in step S15 of Example 1.

[0022] Figure 11 This is a structural diagram of the pressed laminate after processing in step S16 of Example 1.

[0023] Figure 12 This is a structural diagram of the laminated plate after printing the flexural ink in step S17 of Example 1.

[0024] Figure 13 This is a structural diagram of the laminated plate after printing high-temperature resistant peelable ink in step S18 of Example 1.

[0025] Figure 14 This is a structural diagram of the pressed laminated plate after step S19 of Example 1.

[0026] Figure 15 This is a structural diagram of the pressed laminated plate after the cover is removed in step S20 of Example 1.

[0027] Figure 16 This is a structural diagram of the pressed laminated plate after the cover is removed in step S21 of Example 1.

[0028] Figure 17 This is a structural diagram of the finished printed circuit board after removing the high-temperature resistant peelable ink in step S22 of Example 1.

[0029] Figure 18 This is a structural diagram of the printed circuit board product obtained in Example 2. Detailed Implementation

[0030] The present invention will be further described below with reference to specific embodiments.

[0031] The first substrate 1, the second substrate 4, and the third substrate 6 used in the following embodiments are all provided by Taiguang Electronic Materials Co., Ltd., model number: EM825(I). The first substrate 1.3, the second substrate 4.3, and the third substrate 6.3 in the first substrate 1, the second substrate 4, and the third substrate 6 are all epoxy resin substrates, and their thicknesses are all 50-75 micrometers. The thicknesses of the copper foil 1.1 on the first substrate, the copper foil 1.2 on the first substrate, the copper foil 4.1 on the second substrate, the copper foil 4.2 on the second substrate, the copper foil 6.1 on the third substrate, and the copper foil 6.2 on the third substrate are all 12-34 micrometers.

[0032] The first prepreg 3, the second prepreg 5, the third prepreg 7 and the fourth prepreg 9 used in the following embodiments were provided by Taiguang Electronic Materials Co., Ltd., model number: EM825(I), and their thickness is 50-90 micrometers.

[0033] In the following embodiments, the thickness of the first copper foil 8 and the second copper foil 10 is 12-17 micrometers.

[0034] Example 1 A type of printed circuit board that can be used for semi-bent high interconnection, such as Figure 17 As shown, it includes a first substrate 1, a first prepreg 3, a second substrate 4, a second prepreg 5, a third substrate 6, a third prepreg 7, a first copper foil 8, a fourth prepreg 9, a second copper foil 10, and a bend-resistant ink 12. A fourth prepreg 9 is provided on the upper surface of the second copper foil 10. A first substrate 1 is provided on the upper surface of the fourth prepreg 9. The first substrate 1 includes a first substrate 1.3, a first substrate upper copper foil 1.1 located on the upper surface of the first substrate 1.3, and a first substrate lower copper foil 1.2 located on the lower surface of the first substrate 1.3. A first prepreg 3 is provided on the upper surface of the first substrate upper copper foil 1.1. A second substrate 4 is provided on the upper surface of the first prepreg 3. The first substrate 4 includes a second substrate 4.3, a second substrate upper copper foil 1.2 located on the upper surface of the second substrate 4.3, and a first substrate lower copper foil 1.2 located on the upper surface of the second substrate 4.3. The copper foil 4.1 and the copper foil 4.2 on the lower surface of the second substrate 4.3 are provided on the upper surface of the copper foil 4.1 on the second substrate. A third substrate 6 is provided on the upper surface of the second semi-cured sheet 5. The third substrate 6 includes a third substrate 6.3, a copper foil 6.1 on the upper surface of the third substrate 6.3 and a copper foil 6.2 on the lower surface of the third substrate 6.3. A third semi-cured sheet 7 is provided on the upper surface of the copper foil 6.1 on the third substrate. A first copper foil 8 is provided on the upper surface of the third semi-cured sheet 7. Lines are etched on the second copper foil 10, the copper foil 1.1 on the first substrate, the copper foil 1.2 on the first substrate, the copper foil 4.1 on the second substrate, the copper foil 4.2 on the second substrate, the copper foil 6.1 on the third substrate, the copper foil 6.2 on the third substrate, and the first copper foil 8. A window groove 14 is provided above the first substrate 1.3, so that the upper surface of the first substrate 1.3 within the window groove 14 is exposed, and a bend-resistant ink 12 is provided on the lower surface of the second copper foil 10 within the corresponding window groove 14. A first laser blind hole is provided on the first copper foil 8 located at the top layer and the third prepreg 7 adjacent to it. The first laser blind hole penetrates the first copper foil 8 and the third prepreg 7, so that the upper surface of the copper foil 6.1 on the third substrate is exposed. A frustum-shaped first interconnect post 11.1 is provided in the first laser blind hole. A second laser blind hole is provided on the second copper foil 10 and the upper fourth prepreg 9. The second laser blind hole penetrates the second copper foil 10 and the fourth prepreg 9, so that the lower surface of the lower copper foil 1.2 on the first substrate is exposed. A frustum-shaped second interconnect post 11.2 is provided in the second laser blind hole. A through hole is provided between the upper surface of the first copper foil 8 and the lower surface of the second copper foil 10, and an integral interconnecting post 11.3 is provided in the through hole.

[0035] The above-described method for manufacturing semi-bent high-interconnect printed circuit boards includes the following steps: S1. A first substrate 1 is provided, the first substrate 1 including a first base material 1.3, a first substrate upper copper foil 1.1 located on the upper surface of the first base material 1.3, and a first substrate lower copper foil 1.2 located on the lower surface of the first base material 1.3, as shown below. Figure 1 As shown; S2. Etch circuits on the copper foil 1.1 on the first substrate and the copper foil 1.2 on the lower substrate, and simultaneously etch a window groove in the middle of the copper foil 1.1 on the first substrate. The window groove penetrates the front and rear faces of the copper foil 1.1 on the first substrate. Print a high-temperature resistant peelable wet film 2 inside the window groove, such as... Figure 2 As shown; S3. A first prepreg 3 is provided. Laser cutting is used to create slits on the first prepreg 3 at the positions corresponding to the left and right edges of the window slot in S2. The slits penetrate the upper and lower surfaces of the first prepreg 3, and a distance is left between the rear end of each slit and the rear end face of the first prepreg 3, and between the front end of each slit and the front end face of the first prepreg 3. Figure 3 As shown; S4. A second substrate 4 is provided. The second substrate 4 includes a second base material 4.3, a copper foil 4.1 on the upper surface of the second base material 4.3, and a copper foil 4.2 on the lower surface of the second base material 4.3. Circuits are etched on the copper foil 4.1 and the copper foil 4.2. A slit is laser-cut on the copper foil 4.1 at the left and right edges of the window slot corresponding to S2. The slit penetrates the copper foil 4.1 and extends a certain distance into the second base material 4.3. The copper foil 4.1 on the second base material and the copper foil 4.2 at the left and right edges of the window slot corresponding to S2 are laser-cut. The slit penetrates the copper foil 4.1 and extends a certain distance into the second base material 4.3. The second base material 4.3 is not cut through. Figure 4As shown; S5, Provide a second semi-cured sheet 5, such as Figure 5 As shown; S6. A third substrate 6 is provided, the third substrate 6 including a third substrate 6.3, a third substrate upper copper foil 6.1 located on the upper surface of the third substrate 6.3, and a third substrate lower copper foil 6.2 located on the lower surface of the third substrate 6.3. Circuits are etched on the third substrate upper copper foil 6.1 and the third substrate lower copper foil 6.2, such as... Figure 6 As shown; S7. Provide a third prepreg 7, a first copper foil 8, a fourth prepreg 9, and a second copper foil 10; S8. The second copper foil 10, the fourth prepreg 9, the first substrate 1, the first prepreg 3, at least one second substrate 4, the second prepreg 5, at least one third substrate 6, the third prepreg 7, and the first copper foil 8 are stacked together in a bottom-up order, such that a first prepreg 3 is provided between adjacent second substrates 4, and a second prepreg 5 is provided between adjacent third substrates 6. All materials are pressed together to form a laminated stack, such as... Figure 7 As shown; S9. Etch lines on the second copper foil 10 and the first copper foil 8 of the laminated plate; S10. The laminated plate, the third semi-cured sheet 7 and the first copper foil 8 are stacked and pressed together in a bottom-up order; S11. Etch a circuit on the topmost copper foil 8; S12. Repeat steps S10 to S11 as required 0 times; S13. A first laser blind via is drilled on the topmost copper foil 8, penetrating the first copper foil 8 and the third prepreg 7, exposing the upper surface of the copper foil adjacent to the topmost copper foil 8; a second laser blind via is drilled on the second copper foil 10, penetrating the second copper foil 10 and the fourth prepreg 9, exposing the lower surface of the copper foil 1.2 under the first substrate. Figure 8 As shown; S14. Drill a through hole between the upper surface of the first copper foil 8 and the lower surface of the second copper foil 10, as shown. Figure 9 As shown; S15. Copper is plated into the first and second laser blind vias formed in S13 to form the first interconnect pillar 11.1 and the second interconnect pillar 11.2, respectively. Copper is plated into the wall of the through hole formed in S14 to form the integral interconnect pillar 11.3, as shown. Figure 10 As shown; S16, circuits are etched on the first copper foil 8 and the second copper foil 10, and the first copper foil 8 in the window slot area corresponding to S2 is etched away, exposing the upper surface of the third prepreg 7, such as... Figure 11 As shown; S17. Print bend-resistant ink 12 on the second copper foil 10 at the window slot position corresponding to S2, such as Figure 12 As shown; S18. Print a first high-temperature resistant peelable ink 13.1 on the area outside the window groove of S2 on the first copper foil 8, and print a second high-temperature resistant peelable ink 13.2 on the area outside the bending resistant ink 12 on the second copper foil 10, as shown. Figure 13 As shown; S19. Along the left and right lines of the window groove in S2, perform a scooping operation on the third prepreg 7, with the scooping depth reaching below the upper surface of the bottommost second prepreg 5. Figure 14 As shown; S20. Uncover the film to expose the high-temperature resistant peelable wet film 2, forming a deep window groove 14 at the uncovering point, such as... Figure 15 As shown; S21, Remove the high-temperature resistant peelable wet film 2, such as Figure 16 As shown; S22. Remove the first high-temperature resistant peelable ink 13.1 and the second high-temperature resistant peelable ink 13.2 to obtain a semi-bent high-interconnect printed circuit board, such as... Figure 17 As shown.

[0036] The semi-bent high interconnect printed circuit board obtained in Example 1 can be bent at an angle of 90° at the window deep groove 14 position, and the number of bends is ≥1000.

[0037] Example 2 A type of printed circuit board that can be used for semi-bent high interconnection, such as Figure 18 As shown, it includes a first substrate 1, a first prepreg 3, a second substrate 4, a second prepreg 5, a third substrate 6, a third prepreg 7, a first copper foil 8, a fourth prepreg 9, a second copper foil 10, and a bend-resistant ink 12. A fourth prepreg 9 is provided on the upper surface of the second copper foil 10. A first substrate 1 is provided on the upper surface of the fourth prepreg 9. The first substrate 1 includes a first substrate 1.3, a first substrate upper copper foil 1.1 located on the upper surface of the first substrate 1.3, and a first substrate lower copper foil 1.2 located on the lower surface of the first substrate 1.3. A first prepreg 3 is provided on the upper surface of the first substrate upper copper foil 1.1. Two second substrates 4 stacked together are provided on the upper surface of the first prepreg 3. A first prepreg 3 is provided between adjacent second substrates 4. The second substrate 4 includes a second substrate 4.3, a second substrate upper copper foil 4.1 located on the upper surface of the second substrate 4.3, and a first substrate lower copper foil 1.2 located on the lower surface of the second substrate 1.3. 4.3 The lower surface of the second substrate has a second substrate lower copper foil 4.2. The upper surface of the copper foil 4.1 on the second substrate has a second prepreg 5. The upper surface of the second prepreg 5 has two stacked third substrates 6. The second prepreg 5 is provided between adjacent third substrates 6. The third substrate 6 includes a third substrate 6.3, a third substrate upper copper foil 6.1 located on the upper surface of the third substrate 6.3, and a third substrate lower copper foil 6.2 located on the lower surface of the third substrate 6.3. The upper surface of the copper foil 6.1 on the third substrate has a third prepreg 7. The upper surface of the third prepreg 7 has two stacked first copper foils 8. The third prepreg 7 is provided between adjacent first copper foils 8. Lines are etched on the second copper foil 10, the copper foil 1.1 on the first substrate, the copper foil 1.2 on the first substrate, the copper foil 4.1 on the second substrate, the copper foil 4.2 on the second substrate, the copper foil 6.1 on the third substrate, the copper foil 6.2 on the third substrate, and the first copper foil 8. A window groove 14 is provided above the first substrate 1.3, so that the upper surface of the first substrate 1.3 within the window groove 14 is exposed, and a bend-resistant ink 12 is provided on the lower surface of the second copper foil 10 within the corresponding window groove 14. A first laser blind hole is provided on the topmost first copper foil 8 and the adjacent third prepreg 7. The first laser blind hole penetrates the first copper foil 8 and the third prepreg 7, exposing the upper surface of the copper foil adjacent to the topmost first copper foil 8. A frustum-shaped first interconnect post 11.1 is provided in the first laser blind hole. A second laser blind hole is provided on the second copper foil 10 and the upper fourth prepreg 9. The second laser blind hole penetrates the second copper foil 10 and the fourth prepreg 9, exposing the lower surface of the lower copper foil 1.2 of the first substrate. A frustum-shaped second interconnect post 11.2 is provided in the second laser blind hole. A through hole is provided between the upper surface of the first copper foil 8 and the lower surface of the second copper foil 10, and an integral interconnecting post 11.3 is provided in the through hole.

[0038] The above-described method for manufacturing semi-bent high-interconnect printed circuit boards includes the following steps: S1. A first substrate 1 is provided, the first substrate 1 including a first base material 1.3, a first substrate upper copper foil 1.1 located on the upper surface of the first base material 1.3, and a first substrate lower copper foil 1.2 located on the lower surface of the first base material 1.3; S2. Etch lines on copper foil 1.1 on the first substrate and copper foil 1.2 on the lower substrate, and simultaneously etch a window groove in the middle of copper foil 1.1 on the first substrate. The window groove passes through the front end and rear end of copper foil 1.1 on the first substrate. Print a high-temperature resistant peelable wet film 2 in the window groove. S3. Provide a first semi-cured sheet 3. Laser-cut slits are made on the first semi-cured sheet 3 at the left and right lines of the window slot corresponding to S2. The slits penetrate the upper and lower surfaces of the first semi-cured sheet 3. A distance is left between the rear end of each slit and the rear end face of the first semi-cured sheet 3, and between the front end of each slit and the front end face of the first semi-cured sheet 3. S4. A second substrate 4 is provided. The second substrate 4 includes a second base material 4.3, a second substrate upper copper foil 4.1 located on the upper surface of the second substrate 4.3, and a second substrate lower copper foil 4.2 located on the lower surface of the second substrate 4.3. Circuits are etched on the second substrate upper copper foil 4.1 and the second substrate lower copper foil 4.2. A slit is laser-cut on the second substrate upper copper foil 4.1 at the left and right lines of the window slot corresponding to S2. The slit penetrates the second substrate upper copper foil 4.1 and extends into the second substrate 4.3 for a certain distance. The second substrate 4.3 is not cut through. S5, Provide a second semi-cured sheet 5; S6. Provide a third substrate 6, which includes a third substrate 6.3, a third substrate upper copper foil 6.1 located on the upper surface of the third substrate 6.3, and a third substrate lower copper foil 6.2 located on the lower surface of the third substrate 6.3. Etch lines on the third substrate upper copper foil 6.1 and the third substrate lower copper foil 6.2. S7. Provide a third prepreg 7, a first copper foil 8, a fourth prepreg 9, and a second copper foil 10; S8. The second copper foil 10, the fourth prepreg 9, the first substrate 1, the first prepreg 3, two second substrates 4, the second prepreg 5, two third substrates 6, the third prepreg 7 and the first copper foil 8 are stacked together in a bottom-up order, so that the first prepreg 3 is provided between adjacent second substrates 4 and the second prepreg 5 is provided between adjacent third substrates 6, and all materials are pressed together to form a press-fit stack. S9. Etch lines on the second copper foil 10 and the first copper foil 8 of the laminated plate; S10. The laminated plate, the third semi-cured sheet 7 and the first copper foil 8 are stacked and pressed together in a bottom-up order; S11. Etch a circuit on the topmost copper foil 8; S12. Repeat steps S10 to S11 as required once; S13. A first laser blind hole is drilled on the topmost first copper foil 8, the first laser blind hole penetrating the first copper foil 8 and the third prepreg 7, so that the upper surface of the copper foil adjacent to the topmost first copper foil 8 is exposed; a second laser blind hole is drilled on the second copper foil 10, the second laser blind hole penetrating the second copper foil 10 and the fourth prepreg 9, so that the lower surface of the first substrate lower copper foil 1.2 is exposed; S14. Drill a through hole between the upper surface of the first copper foil 8 and the lower surface of the second copper foil 10. S15. Copper is plated in the first laser blind hole and the second laser blind hole formed in S13 to form the first interconnect pillar 11.1 and the second interconnect pillar 11.2 respectively. Copper is plated on the hole wall of the through hole formed in S14 to form the integral interconnect pillar 11.3. S16. Lines are etched on the first copper foil 8 and the second copper foil 10, and the first copper foil 8 in the window slot area corresponding to S2 is etched away, so that the upper surface of the third prepreg 7 is exposed. S17. Print bend-resistant ink 12 on the second copper foil 10 at the window slot position corresponding to S2; S18. Print a first high-temperature resistant peelable ink 13.1 on the area outside the window groove of the first copper foil 8 corresponding to S2, and print a second high-temperature resistant peelable ink 13.2 on the area outside the second copper foil 10 corresponding to the bending resistant ink 12. S19. Along the left and right lines of the window groove in S2, the third semi-cured sheet 7 is grouted, and the grooving depth reaches below the upper surface of the bottom second semi-cured sheet 5. S20. Uncover the cover to expose the high-temperature resistant peelable wet film 2, forming a window groove 14 at the uncovering point; S21. Remove the high-temperature resistant peelable wet film 2; S22. Remove the first high-temperature resistant peelable ink 13.1 and the second high-temperature resistant peelable ink 13.2 to obtain a semi-bent high interconnect printed circuit board.

[0039] The semi-bent high interconnect printed circuit board obtained in Example 2 can be bent at an angle of 90° at the window deep groove 14 position, and the number of bends is ≥1000.

Claims

1. A semi-flexible high interconnect printed circuit board, comprising a first substrate (1), a first prepreg (3), a second substrate (4), a second prepreg (5), a third substrate (6), a third prepreg (7), a first copper foil (8), a fourth prepreg (9), a second copper foil (10), and a bend-resistant ink (12). Its characteristics are: A fourth prepreg (9) is provided on the upper surface of the second copper foil (10). A first substrate (1) is provided on the upper surface of the fourth prepreg (9). The first substrate (1) includes a first substrate (1.3), a first substrate upper copper foil (1.1) located on the upper surface of the first substrate (1.3), and a first substrate lower copper foil (1.2) located on the lower surface of the first substrate (1.3). A first prepreg (3) is provided on the upper surface of the first substrate upper copper foil (1.1). One or more second substrates (4) stacked together are provided on the upper surface of the first prepreg (3). A first prepreg (3) is provided between adjacent second substrates (4). The second substrate (4) includes a second substrate (4.3), a second substrate upper copper foil (4.1) located on the upper surface of the second substrate (4.3), and a second substrate lower copper foil (1.2) located on the lower surface of the second substrate (4.3). .3) The second substrate lower copper foil (4.2) on the lower surface, the second semi-cured sheet (5) is provided on the upper surface of the copper foil (4.1) on the second substrate, one or more third substrates (6) stacked together are provided on the upper surface of the second semi-cured sheet (5), and the second semi-cured sheet (5) is provided between adjacent third substrates (6). The third substrate (6) includes a third substrate (6.3), a third substrate upper copper foil (6.1) located on the upper surface of the third substrate (6.3) and a third substrate lower copper foil (6.2) located on the lower surface of the third substrate (6.3). The third semi-cured sheet (7) is provided on the upper surface of the copper foil (6.1) on the third substrate, and one or more first copper foils (8) stacked together are provided on the upper surface of the third semi-cured sheet (7). The third semi-cured sheet (7) is provided between adjacent first copper foils (8). Lines are etched on the second copper foil (10), the copper foil on the first substrate (1.1), the copper foil under the first substrate (1.2), the copper foil on the second substrate (4.1), the copper foil under the second substrate (4.2), the copper foil on the third substrate (6.1), the copper foil under the third substrate (6.2), and the first copper foil (8); A window groove (14) is provided above the first substrate (1.3) so that the upper surface of the first substrate (1.3) within the window groove (14) is exposed, and a bend-resistant ink (12) is provided on the lower surface of the second copper foil (10) within the corresponding window groove (14). A first laser blind hole is provided on the topmost first copper foil (8) and the adjacent third prepreg (7). The first laser blind hole penetrates the first copper foil (8) and the third prepreg (7), exposing the upper surface of the copper foil adjacent to the topmost first copper foil (8). A first interconnect post (11.1) is provided in the first laser blind hole. A second laser blind hole is provided on the second copper foil (10) and the upper fourth prepreg (9). The second laser blind hole penetrates the second copper foil (10) and the fourth prepreg (9), exposing the lower surface of the first substrate lower copper foil (1.2). A second interconnect post (11.2) is provided in the second laser blind hole. A through hole is provided between the upper surface of the first copper foil (8) and the lower surface of the second copper foil (10), and an integral interconnecting post (11.3) is provided in the through hole.

2. The semi-flexible high-interconnect printed circuit board as described in claim 1, characterized in that: Both the first interconnect post (11.1) and the second interconnect post (11.2) are frustum-shaped.

3. The manufacturing method for semi-curved high-interconnect printed circuit boards as described in claim 1, characterized in that: The method includes the following steps: S1. A first substrate (1) is provided. The first substrate (1) includes a first substrate (1.3), a first substrate upper copper foil (1.1) located on the upper surface of the first substrate (1.3), and a first substrate lower copper foil (1.2) located on the lower surface of the first substrate (1.3). S2. Etch lines on the copper foil (1.1) on the first substrate and the copper foil (1.2) on the lower substrate, and simultaneously etch a window groove in the middle of the copper foil (1.1) on the first substrate. The window groove passes through the front end and rear end of the copper foil (1.1) on the first substrate. Print a high-temperature resistant peelable wet film (2) in the window groove. S3. Provide a first semi-cured sheet (3). Laser cutting is used to make slits on the first semi-cured sheet (3) at the left and right lines of the window slot corresponding to S2. The slits penetrate the upper and lower surfaces of the first semi-cured sheet (3). A distance is left between the rear end of each slit and the rear end face of the first semi-cured sheet (3) and between the front end of each slit and the front end face of the first semi-cured sheet (3). S4. A second substrate (4) is provided. The second substrate (4) includes a second substrate (4.3), a second substrate upper copper foil (4.1) located on the upper surface of the second substrate (4.3), and a second substrate lower copper foil (4.2) located on the lower surface of the second substrate (4.3). Circuits are etched on the second substrate upper copper foil (4.1) and the second substrate lower copper foil (4.2). A slit is laser-cut on the second substrate upper copper foil (4.1) at the left and right line positions of the window slot corresponding to S2. The slit penetrates the second substrate upper copper foil (4.1) and extends into the second substrate (4.3) for a certain distance. The second substrate upper copper foil (4.1) is laser-cut on the second substrate lower copper foil (4.2) at the left and right line positions of the window slot corresponding to S2. The slit penetrates the second substrate upper copper foil (4.1) and extends into the second substrate (4.3) for a certain distance. The second substrate (4.3) is not cut through. S5. Provide a second semi-cured sheet (5); S6. Provide a third substrate (6), the third substrate (6) includes a third substrate (6.3), a third substrate upper copper foil (6.1) located on the upper surface of the third substrate (6.3) and a third substrate lower copper foil (6.2) located on the lower surface of the third substrate (6.3), and etch lines on the third substrate upper copper foil (6.1) and the third substrate lower copper foil (6.2); S7. Provide a third prepreg (7), a first copper foil (8), a fourth prepreg (9), and a second copper foil (10). S8. The second copper foil (10), the fourth prepreg (9), the first substrate (1), the first prepreg (3), at least one second substrate (4), the second prepreg (5), at least one third substrate (6), the third prepreg (7) and the first copper foil (8) are stacked together in a bottom-up order, so that the first prepreg (3) is provided between adjacent second substrates (4) and the second prepreg (5) is provided between adjacent third substrates (6), and all materials are pressed together to form a press-fit stack. S9. Etch lines on the second copper foil (10) and the first copper foil (8) of the laminated plate; S10. The laminated plate, the third semi-cured sheet (7) and the first copper foil (8) are stacked and pressed together in a bottom-up order; S11. Etch a line on the first copper foil (8) located on the topmost layer; S12. Repeat steps S10 to S11 as required; S13. A first laser blind hole is drilled on the first copper foil (8) located at the top layer. The first laser blind hole penetrates the first copper foil (8) and the third prepreg (7), so that the upper surface of the copper foil adjacent to the first copper foil (8) is exposed. A second laser blind hole is drilled on the second copper foil (10). The second laser blind hole penetrates the second copper foil (10) and the fourth prepreg (9), so that the lower surface of the copper foil (1.2) under the first substrate is exposed. S14. Drill a through hole between the upper surface of the first copper foil (8) and the lower surface of the second copper foil (10); S15. Copper is plated in the first laser blind hole and the second laser blind hole formed in S13 to form the first interconnect pillar (11.1) and the second interconnect pillar (11.2) respectively. Copper is plated on the hole wall of the through hole formed in S14 to form the integral interconnect pillar (11.3). S16, the first copper foil (8) and the second copper foil (10) are etched with lines and the first copper foil (8) in the window slot area corresponding to S2 is etched away, so that the upper surface of the third prepreg (7) is exposed. S17. Print resistant ink (12) on the second copper foil (10) and at the window slot position corresponding to S2. S18. Print a first high-temperature resistant peelable ink (13.1) on the area outside the window groove of S2 on the first copper foil (8), and print a second high-temperature resistant peelable ink (13.2) on the area outside the bending resistant ink (12) on the second copper foil (10). S19. Along the left and right lines of the window groove of S2, the third semi-cured sheet (7) is grouted, and the grooving depth reaches the position below the upper surface of the bottom second semi-cured sheet (5). S20. Uncover the cover to expose the high-temperature resistant peelable wet film (2) and form a window groove (14) at the uncovering point. S21. Remove the high-temperature resistant peelable wet film (2); S22, Remove the first high-temperature resistant peelable ink (13.1) and the second high-temperature resistant peelable ink (13.2) to obtain a semi-bent high interconnect printed circuit board.

4. The manufacturing method of a semi-bent high interconnect printed circuit board as described in claim 3, characterized in that: in S8, the number of the first substrate (1) is one, the number of the second substrate (4) is 1-5, and the number of the third substrate (6) is 1-5.

5. The manufacturing method for semi-curved high-interconnect printed circuit boards as described in claim 3, characterized in that: In S12, the steps from S10 to S11 are repeated 0-4 times.

6. The manufacturing method for semi-curved high-interconnect printed circuit boards as described in claim 3, characterized in that: In S13, both the first and second laser blind holes are frustum-shaped. The diameter of the large end of the first laser blind hole is 0.1-0.15 mm and the diameter of the small end is 0.085-0.1 mm. The diameter of the large end of the second laser blind hole is 0.1-0.15 mm and the diameter of the small end is 0.085-0.1 mm.

7. The manufacturing method for semi-curved high-interconnect printed circuit boards as described in claim 3, characterized in that: In S14, the diameter of the through hole is 0.15-3 mm.

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