Uncovering method for closed cavity of printed circuit board
By making alignment marks on the cover of the printed circuit board and uncovering the cover using handles with adhesive and peeling layers, the problem of difficulty in removing the cover of the closed cavity is solved, and rapid and efficient uncovering is achieved The process avoids Bonding Pad damage and residual glue problems.
Patent Information
- Application Number
- CN202411452224.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-10-17
- Publication Date
- 2025-01-03
AI Technical Summary
During the processing of the closed cavity, the lack of stress concentration points makes it difficult to remove the cover plate, causing quality problems such as Bonding Pad damage and residual glue.
The alignment mark is made on the cover plate of the printed circuit board, and the handle with the adhesive layer and the peeling layer is used for pre-sticking and pressing of auxiliary materials, so as to achieve rapid and efficient uncovering of the cover plate through the handle.
It effectively avoids damage to the cover plate during the uncovering process, improves the removal efficiency of the closed cavity cover plate, and reduces the occurrence of quality problems.
Smart Images
Figure CN119255515A_ABST
Abstract
Description
Technical Field
[0001] The invention relates to the technical field of printed circuit boards, in particular to a method for uncovering a sealed cavity of a printed circuit board. Background Art
[0002] With the continuous development of electronic technology, the market has higher and higher requirements for the performance and reliability of electronic products. The development of closed cavity gold wire punching technology is to meet these needs. By providing high-performance packaging and protection solutions and adopting advanced packaging technology, it ensures that electronic products can still work stably in complex environments, effectively protects electronic components from the influence of the external environment, and enhances the electrical performance and mechanical strength of the product. This technology not only improves the reliability of the product, but also extends the service life of the product.
[0003] The most important step in the processing of printed circuit boards with closed cavities is the processing of the closed cavities. Generally, the method of removing excess material on the surface of the closed cavity and then exposing the closed cavity is adopted. The difficulty of this method is that there is no open space around the closed cavity, and there is no stress concentration point when the cover is opened, which makes it difficult to remove the cover plate above the closed cavity, resulting in a series of quality problems such as damage to the bonding pad in the closed cavity and residual glue on the cover plate. Summary of the invention
[0004] In view of the deficiencies in the prior art, the present invention provides a method for uncovering a sealed cavity of a printed circuit board, which can quickly and efficiently uncover the cover of the sealed cavity.
[0005] The technical solution adopted by the present invention is: A method for uncovering a sealed cavity of a printed circuit board, comprising the following steps: Step S1. manufacturing a printed circuit board, wherein at least one closed cavity is formed on the printed circuit board, a cover plate is provided on one side of the printed circuit board corresponding to the closed cavity, and an alignment mark is made on the cover plate; Step S2. Making a handle, wherein the handle comprises an adhesive layer and a peeling layer arranged in sequence from bottom to top; Step S3. Pre-pasting the prepared handle on the alignment mark position of the cover plate; Step S4. placing a pressing auxiliary material on the cover plate of the printed circuit board and pressing the printed circuit board; Step S5. Open the cover plate on the surface of the printed circuit board through the handle to obtain a finished product.
[0006] Preferably, in the method for uncovering the sealed cavity of a printed circuit board, step S1 specifically comprises the following steps: Step S10. Provide a first rigid board, the first rigid board comprising a first insulating layer, a first upper copper foil layer disposed on the upper surface of the first insulating layer, and a first lower copper foil layer disposed on the lower surface of the first insulating layer, make a circuit pattern on the first lower copper foil layer, cut a first slit on the lower side of the first insulating layer corresponding to the closed cavity by UV laser, and then perform browning treatment; Step S11. Provide a second rigid board, the second rigid board comprising a second insulating layer, a second upper copper foil layer disposed on the upper surface of the second insulating layer, and a second lower copper foil layer disposed on the lower surface of the second insulating layer, make circuit patterns on both the second upper copper foil layer and the second lower copper foil layer, then set a peelable protective film at a position of the second upper copper foil layer corresponding to the closed cavity, and finally perform lamination and browning treatment in sequence; Step S12. Providing a third rigid board, the third rigid board comprising a third insulating layer, a third upper copper foil layer disposed on the upper surface of the third insulating layer, and a third lower copper foil layer disposed on the lower surface of the third insulating layer, making a circuit pattern on the third upper copper foil layer, and then performing a browning treatment; Step S13. Provide a first prepreg and a second prepreg, and open a window at a position corresponding to the sealed cavity on the second prepreg to form a window area; Step S14. stacking the third hard board, the first prepreg, the second hard board layer, the second prepreg, and the first hard board in order from bottom to top, and then pressing them together to obtain a semi-finished product, wherein the semi-finished product includes at least one closed cavity; Step S15. Drilling, electroplating, making outer circuits, and solder masking the semi-finished product. When making the outer circuits, make alignment marks on the cover plate to obtain a printed circuit board; Step S16: laser cut a second slit on the upper side of the first insulating layer at a position corresponding to the first slit of the printed circuit board, and then inspect the cutting depth by sectioning with a gold imaging microscope.
[0007] Preferably, in the method for uncovering the sealed cavity of a printed circuit board, the depth of the first gap in step S10 is 0.05mm-0.1mm; the speed of the browning treatment is 3.0-4.0m / min, the browning line micro-etching rate is 40-60uinch, and the browning temperature is 33-38°C.
[0008] Preferably, in the method for uncovering the sealed cavity of a printed circuit board, wherein: in step S11, the length of the peelable protective film is 0.1mm-0.2mm smaller than the length of a single side of the sealed cavity; in step S13, the length of the second semi-cured sheet window area is 0.125mm-0.25mm larger than the length of a single side of the sealed cavity; and in step S16, the depth of the second gap is 0.025mm-0.1mm.
[0009] Preferably, in the method for uncovering the sealed cavity of a printed circuit board, in step S2, the length of the adhesive layer is 0.4-1.0 mm shorter than the length of one side of the cover plate, and the length of at least one side of the peeling layer is 5-10 mm longer than the length of one side of the cover plate.
[0010] Preferably, in the method for uncovering the sealed cavity of a printed circuit board, step S3 is specifically as follows: Step S31. Provide a window opening jig, design circular holes with the same diameter at the same position in the waste area of the printed circuit board and the window opening jig, and then set the window opening jig on the surface of the cover plate of the printed circuit board through a fixing member, and fix them together to expose the cover plate; Step S32. Pre-stick the handle to the alignment mark position of the cover plate after aligning it with the window opening fixture, and check whether the handle deviates from the mark after pre-sticking through the alignment mark. After the pre-sticking is qualified, pre-press the handle and the printed circuit board.
[0011] Preferably, in the method for uncovering the sealed cavity of a printed circuit board, the alignment mark in step S32 includes an alignment center line, an offset upper line and an offset lower line, and the interval between the offset upper line and the offset lower line and the alignment center line is 0.2 mm.
[0012] Preferably, in the method for uncovering the sealed cavity of a printed circuit board, in step S31, the window length of the window opening fixture is 0.05-0.1 mm greater than the single side length of the handle.
[0013] Preferably, in the method for uncovering the sealed cavity of a printed circuit board, in step S32, the pre-pressing temperature is 150-180°C, the pre-pressing pressure is 3-10kg, and the pre-pressing time is 10-30S.
[0014] Preferably, in the method for uncovering the sealed cavity of a printed circuit board, the pressing temperature in step S4 is 150-170° C., the pressing time is 30-80 min, and the pressing pressure is 100-300 PSI.
[0015] Advantages of the present invention: (1) The method for uncovering a sealed cavity of a printed circuit board of the present invention comprises the following steps: making an alignment mark on the cover of the printed circuit board, making a handle, pre-pasting the made handle at the alignment mark position of the cover, placing a pressing auxiliary material on the cover of the printed circuit board, and uncovering the cover by the handle. The handle design is added to the cavity cover, so that the cover of the sealed cavity can be uncovered quickly and efficiently. BRIEF DESCRIPTION OF THE DRAWINGS
[0016] Figure 1 It is a cross-sectional view of the first hard plate of the present invention.
[0017] Figure 2It is a plan view of the first hard board of the present invention.
[0018] Figure 3 It is a cross-sectional view of the second hard plate of the present invention.
[0019] Figure 4 It is a cross-sectional view of the third hard board of the present invention.
[0020] Figure 5 It is a cross-sectional view of the second prepreg of the present invention.
[0021] Figure 6 It is a structural schematic diagram of the semi-finished product of the present invention.
[0022] Figure 7 It is a schematic diagram of the structure of the printed circuit board of the present invention.
[0023] Figure 8 It is a cross-sectional view of the printed wiring board of the present invention.
[0024] Fig. 9 It is a schematic diagram of the structure of the second slit cut by laser on the printed circuit board of the present invention.
[0025] Fig.10 This is a schematic diagram of the structure of making a handle on the cover plate of the present invention.
[0026] Fig.11 It is a schematic diagram of the structure of the handle of the present invention.
[0027] Fig.12 It is a structural schematic diagram of the window opening fixture of the present invention.
[0028] Fig.13 It is a schematic diagram of the structure of placing pressing auxiliary materials on the cover plate of the printed circuit board of the present invention.
[0029] Fig.14 The present invention is a schematic structural diagram of a printed circuit board cover plate being opened by a handle.
[0030] Fig.15 It is a schematic diagram of the finished product structure of the printed circuit board of the present invention. DETAILED DESCRIPTION
[0031] The present invention will be further described below in conjunction with specific drawings and embodiments.
[0032] Example 1 A method for uncovering a sealed cavity of a printed circuit board comprises the following steps: Step S1. manufacturing a printed circuit board 1, wherein at least one sealed cavity is formed on the printed circuit board 1, a cover plate 3 is provided on one side of the printed circuit board 1 corresponding to the sealed cavity, and an alignment mark 14 is made on the cover plate 3; Step S1 specifically includes the following steps: Step S10. Figure 1-2 , providing a first hard board 5, the first hard board 5 has a thickness of 0.1 mm, the first hard board 5 is manufactured by Taiguang Electronic Materials Co., Ltd., the model is EM370D, the first hard board 5 includes a first insulating layer 5-3, a first upper copper foil layer 5-1 arranged on the upper surface of the first insulating layer 5-3, and a first lower copper foil layer 5-2 arranged on the lower surface of the first insulating layer 5-3, a circuit pattern is made on the first lower copper foil layer 5-2, and a first slit 10 is cut on the first lower copper foil layer 5-2 corresponding to the closed cavity 4 by UV laser, the depth of the first slit 10 is 0.05 mm, and then browning treatment is performed, the browning treatment speed is 3.5 m / min, the browning line micro-etching rate is 50uinch, and the browning temperature is 35°C; Step S11. Figure 3 , providing a second hard board 6, the second hard board 6 has a thickness of 0.1mm, the second hard board 6 is manufactured by Taiguang Electronic Materials Co., Ltd., the model is EM370D, the second hard board 6 includes a second insulating layer 6-3, a second upper copper foil layer 6-1 arranged on the upper surface of the second insulating layer 6-3, and a second lower copper foil layer 6-2 arranged on the lower surface of the second insulating layer 6-3, circuit patterns are made on the second upper copper foil layer 6-1 and the second lower copper foil layer 6-2, and then a peelable protective film 11 is arranged at the position of the second upper copper foil layer 6-1 corresponding to the closed cavity, the length of the peelable protective film 11 is 0.1mm less than the single side length of the closed cavity, and finally, pressing and browning treatment are performed in sequence, the pressing temperature is 160°C, the pressing time is 30S, the pressing pressure is 80kg, the browning treatment speed is 3.5m / min, the browning line micro-etching rate is 50uinch, and the browning temperature is 35°C; Step S12. Figure 4 , providing a third hard board 7, the third hard board 7 has a thickness of 0.1 mm, the third hard board 7 comprises a third insulating layer 7-3, a third upper copper foil layer 7-1 disposed on the upper surface of the third insulating layer 7-3, and a third lower copper foil layer 7-2 disposed on the lower surface of the third insulating layer 7-3, making a circuit pattern on the third upper copper foil layer 7-1, and then performing a browning treatment, the browning treatment speed is 3.5 m / min, the browning line micro-etching rate is 50uinch, and the browning temperature is 35°C; Step S13. Figure 5 , providing a first prepreg 8 and a second prepreg 9, the supplier of the first prepreg 8 and the second prepreg 9 is Taiguang Electronic Materials Co., Ltd., the material model is 1080 69% EM370D, opening a window at a position corresponding to the closed cavity on the second prepreg 9 to form a window area 13, the length of the window area 13 is 0.125mm larger than the single side length of the closed cavity 4, and the semi-finished product includes at least one closed cavity; Step S14. Figure 6, stack the third hard board 7, the first prepreg 8, the second hard board layer 6, the second prepreg 9, and the first hard board 5 in order from bottom to top, and then press them at a pressing temperature of 190° C., a pressing time of 120 min, and a pressing pressure of 450 PSI to obtain a semi-finished product; Step S15. Figure 7-8 , drilling, electroplating, making outer layer circuits and solder resist on the semi-finished product, and when making the outer layer circuits, making alignment marks 11 on the cover plate 3 to obtain the printed circuit board 1; Step S16. Fig. 9 , a second slit 12 is laser cut on the first upper copper foil layer 5 - 1 at a position corresponding to the first slit of the printed circuit board 1 , and the cutting depth of the second slit 12 is 0.025 mm, and then the cutting depth is inspected by sectioning with a gold image microscope.
[0033] Step S2. Figure 10-11 , making a handle 2, the handle 2 includes an adhesive layer 2-1 and a peeling layer 2-2 arranged in sequence from bottom to top, the length of the adhesive layer 2-1 is 0.5mm shorter than the single side length of the cover plate 3 (L1 in the figure), and the length of the peeling layer 2-2 is 5mm longer than the single side length of the cover plate 3 on at least one side (L2 in the figure).
[0034] Step S3. Pre-attach the manufactured handle 2 to the alignment mark position of the cover plate 3; Step S3 is specifically as follows: Step S31. Fig.12 , provide a window opening jig 15, design circular holes of the same position and diameter at the same position on the cover plate 3 of the printed circuit board 1 and the waste area of the window opening jig, then fix the window opening jig 15 and the cover plate 3 of the printed circuit board 1 together through a fixing member, the alignment mark 14 includes an alignment center line, an offset upper line and an offset lower line, the offset upper line and the offset lower line are spaced 0.2 mm from the alignment center line, and the window length of the window opening jig is 0.05 mm longer than the single side length of the handle 2 (L3 in the figure); Step S32. After the handle 2 is aligned by a window opening jig, it is pre-attached to the alignment mark position of the cover plate 3, and the handle 2 and the printed circuit board 1 are pre-pressed, with the pre-pressing temperature being 160°C, the pre-pressing pressure being 10kg, and the pre-pressing time being 10S.
[0035] Step S4. Fig.13 , place the pressing auxiliary material 16 on the cover plate 3 of the printed circuit board, and press the printed circuit board 1, the pressing temperature is 160° C., the pressing time is 60 minutes, and the pressing pressure is 150PSI.
[0036] Step S5. Fig.14 , the cover plate 3 on the surface of the printed circuit board 1 is opened through the handle 2, and the finished product is as follows Fig.15 .
[0037] Example 2 A method for uncovering a sealed cavity of a printed circuit board comprises the following steps: Step S1. manufacturing a printed circuit board 1, wherein at least one sealed cavity is formed on the printed circuit board 1, a cover plate 3 is provided on one side of the printed circuit board 1 corresponding to the sealed cavity, and an alignment mark 14 is made on the cover plate 3; Step S1 specifically includes the following steps: Step S10. Figure 1-2 , providing a first hard board 5, the first hard board 5 has a thickness of 1.0 mm, the first hard board 5 is manufactured by Taiguang Electronic Materials Co., Ltd., the model is EM370D, the first hard board 5 includes a first insulating layer 5-3, a first upper copper foil layer 5-1 arranged on the upper surface of the first insulating layer 5-3, and a first lower copper foil layer 5-2 arranged on the lower surface of the first insulating layer 5-3, a circuit pattern is made on the first lower copper foil layer 5-2, and a first slit 10 is cut on the first lower copper foil layer 5-2 corresponding to the closed cavity 4 by UV laser, the depth of the first slit 10 is 0.2 mm, and then browning treatment is performed, the browning treatment speed is 3.5 m / min, the browning line micro-etching rate is 50uinch, and the browning temperature is 35°C; Step S11. Figure 3 , providing a second hard board 6, the second hard board 6 has a thickness of 0.15mm, the second hard board 6 is manufactured by Taiguang Electronic Materials Co., Ltd., the model is EM370D, the second hard board 6 includes a second insulating layer 6-3, a second upper copper foil layer 6-1 arranged on the upper surface of the second insulating layer 6-3, and a second lower copper foil layer 6-2 arranged on the lower surface of the second insulating layer 6-3, circuit patterns are made on the second upper copper foil layer 6-1 and the second lower copper foil layer 6-2, and then a peelable protective film 11 is arranged at the position of the second upper copper foil layer 6-1 corresponding to the closed cavity, the length of the peelable protective film 11 is 0.1mm less than the single side length of the closed cavity, and finally, pressing and browning treatment are performed in sequence, the pressing temperature is 180℃, the pressing time is 15S, the pressing pressure is 90kg, the browning treatment speed is 3.5m / min, the browning line micro-etching rate is 50uinch, and the browning temperature is 35℃; Step S12. Figure 4 , providing a third hard board 7, the third hard board 7 has a thickness of 0.8 mm, the third hard board 7 comprises a third insulating layer 7-3, a third upper copper foil layer 7-1 disposed on the upper surface of the third insulating layer 7-3, and a third lower copper foil layer 7-2 disposed on the lower surface of the third insulating layer 7-3, making a circuit pattern on the third upper copper foil layer 7-1, and then performing a browning treatment, the browning treatment speed is 3.5 m / min, the browning line micro-etching rate is 50uinch, and the browning temperature is 35°C; Step S13. Figure 5, providing a first prepreg 8 and a second prepreg 9, the supplier of the first prepreg 8 and the second prepreg 9 is Taiguang Electronic Materials Co., Ltd., the material model is 1080 69% EM370D, opening a window at a position corresponding to the closed cavity on the second prepreg 9 to form a window area 13, the length of the window area 13 is 0.125mm larger than the single side length of the closed cavity 4, and the semi-finished product includes at least one closed cavity; Step S14. Figure 6 , stack the third hard board 7, the first prepreg 8, the second hard board layer 6, the second prepreg 9, and the first hard board 5 in order from bottom to top, and then press them at a pressing temperature of 185° C., a pressing time of 100 min, and a pressing pressure of 500 PSI to obtain a semi-finished product; Step S15. Figure 7-8 , drilling, electroplating, making outer layer circuits and solder resist on the semi-finished product, and when making the outer layer circuits, making alignment marks 11 on the cover plate 3 to obtain the printed circuit board 1; Step S16. Fig. 9 , a second slit 12 is laser cut on the first upper copper foil layer 5 - 1 at a position corresponding to the first slit of the printed circuit board 1 , and the cutting depth of the second slit 12 is 0.9 mm, and then the cutting depth is inspected by sectioning with a gold image microscope.
[0038] Step S2. Figure 10-11 , making a handle 2, the handle 2 includes an adhesive layer 2-1 and a peeling layer 2-2 arranged in sequence from bottom to top, the length of the adhesive layer 2-1 is 0.4mm shorter than the single side length of the cover plate 3 (L1 in the figure), and the length of the peeling layer 2-2 is at least 6mm longer than the single side length of the cover plate 3 on one side (L2 in the figure).
[0039] Step S3. Pre-attach the manufactured handle 2 to the alignment mark position of the cover plate 3; Step S3 is specifically as follows: Step S31. Fig.12 , provide a window opening jig 15, design circular holes of the same position and diameter at the same position on the cover plate 3 of the printed circuit board 1 and the waste area of the window opening jig, then fix the window opening jig 15 and the cover plate 3 of the printed circuit board 1 together through a fixing member, the alignment mark 14 includes an alignment center line, an offset upper line and an offset lower line, the offset upper line and the offset lower line are spaced 0.2 mm from the alignment center line, and the window length of the window opening jig is 0.05 mm longer than the single side length of the handle 2 (L3 in the figure); Step S32. After the handle 2 is aligned by a window opening jig, it is pre-attached to the alignment mark position of the cover plate 3, and the handle 2 and the printed circuit board 1 are pre-pressed, with the pre-pressing temperature being 170°C, the pre-pressing pressure being 8kg, and the pre-pressing time being 12S.
[0040] Step S4. Fig.13 , place the pressing auxiliary material 16 on the cover plate 3 of the printed circuit board, and press the printed circuit board 1, the pressing temperature is 160° C., the pressing time is 60 minutes, and the pressing pressure is 150PSI.
[0041] Step S5. Fig.14 , the cover plate 3 on the surface of the printed circuit board 1 is opened through the handle 2, and the finished product is as follows Fig.15 .
[0042] Finally, it should be noted that the above specific implementation methods are only used to illustrate the technical solution of the present invention rather than to limit it. Although the present invention has been described in detail with reference to examples, those skilled in the art should understand that the technical solution of the present invention can be modified or replaced by equivalents without departing from the spirit and scope of the technical solution of the present invention, which should be included in the scope of the claims of the present invention.
Claims
1. A method for uncovering a sealed cavity of a printed circuit board, characterized in that: The following steps are involved: Step S1. manufacturing a printed circuit board (1), wherein at least one sealed cavity (4) is formed on the printed circuit board (1), a cover plate (3) is provided on one side of the printed circuit board (1) corresponding to the sealed cavity, and an alignment mark is made on the cover plate (3); Step S2. manufacturing a handle (2), wherein the handle (2) comprises an adhesive layer (2-1) and a peeling layer (2-2) arranged in sequence from bottom to top; Step S3. Pre-attaching the manufactured handle (2) to the alignment mark position of the cover plate (3); Step S4. placing a pressing auxiliary material on the cover plate (3) of the printed circuit board, and pressing the printed circuit board (1); Step S5. The cover plate (3) on the surface of the printed circuit board (1) is removed by using the handle (2) to obtain a finished product.
2. The method for uncovering the sealed cavity of a printed circuit board according to claim 1, characterized in that: Step S1 specifically includes the following steps: Step S10. Providing a first rigid board (5), the first rigid board (5) comprising a first insulating layer (5-3), a first upper copper foil layer (5-1) disposed on the upper surface of the first insulating layer (5-3), and a first lower copper foil layer (5-2) disposed on the lower surface of the first insulating layer (5-3), making a circuit pattern on the first lower copper foil layer (5-2), cutting a first slit (10) on the lower side of the first insulating layer (5-3) corresponding to the closed cavity by UV laser, and then performing a browning treatment; Step S11. providing a second rigid board (6), the second rigid board (6) comprising a second insulating layer (6-3), a second upper copper foil layer (6-1) disposed on the upper surface of the second insulating layer (6-3), and a second lower copper foil layer (6-2) disposed on the lower surface of the second insulating layer (6-3), forming circuit patterns on both the second upper copper foil layer (6-1) and the second lower copper foil layer (6-2), then providing a peelable protective film (11) at a position of the second upper copper foil layer (6-1) corresponding to the sealed cavity, and finally performing lamination and browning treatment in sequence; Step S12. Providing a third rigid board (7), the third rigid board (7) comprising a third insulating layer (7-3), a third upper copper foil layer (7-1) disposed on the upper surface of the third insulating layer (7-3), and a third lower copper foil layer (7-2) disposed on the lower surface of the third insulating layer (7-3), making a circuit pattern on the third upper copper foil layer (7-1), and then performing a browning treatment; Step S13: providing a first prepreg (8) and a second prepreg (9), and opening a window on the second prepreg (9) at a position corresponding to the sealed cavity to form a window area (13); Step S14: stacking the third hard board (7), the first prepreg (8), the second hard board layer (6), the second prepreg (9), and the first hard board (5) in order from bottom to top, and then pressing them together to obtain a semi-finished product, wherein the semi-finished product includes at least one closed cavity; Step S15. Drilling, electroplating, making outer layer circuits, and solder masking the semi-finished product. When making the outer layer circuits, making alignment marks (11) on the cover plate to obtain a printed circuit board (1); Step S16: laser cutting a second slit (12) on the upper side of the first insulating layer (5-3) at a position corresponding to the first slit of the printed circuit board (1), and then inspecting the cutting depth by sectioning with a gold imaging microscope.
3. The method for uncovering the sealed cavity of a printed circuit board according to claim 2, characterized in that: In step S10, the depth of the first gap (10) is 0.05 mm-0.1 mm; the speed of the browning treatment is 3.0-4.0 m / min, the browning line micro-etching rate is 40-60 uinch, and the browning temperature is 33-38°C.
4. The method for uncovering the sealed cavity of a printed circuit board according to claim 2, characterized in that: In step S11, the length of the peelable protective film (11) is 0.1 mm-0.2 mm shorter than the length of a single side of the sealed cavity; in step S13, the length of the window area (13) is 0.125 mm-0.25 mm longer than the length of a single side of the sealed cavity (4); and in step S16, the depth of the second gap (12) is 0.025 mm-0.1 mm.
5. The method for uncovering the sealed cavity of a printed circuit board according to claim 1, characterized in that: In step S2, the length of the adhesive layer (2-1) is 0.4-1.0 mm shorter than the length of a single side of the cover plate (3), and the length of at least one side of the peeling layer (2-2) is 5-10 mm longer than the length of a single side of the cover plate (3).
6. The method for uncovering the sealed cavity of a printed circuit board according to claim 1, characterized in that: Step S3 is specifically as follows: Step S31. Providing a window opening jig (15), designing circular holes with the same diameter at the same position in the waste area of the printed circuit board (1) and the window opening jig (15), and then setting the window opening jig (15) on one side of the cover plate (3) of the printed circuit board (1) through a fixing member, and fixing them together to expose the cover plate (3); Step S32: the handle (2) is aligned with the window opening jig (15) and pre-laminated at the alignment mark position of the cover plate (3), and the alignment mark is used to check whether the handle (2) deviates from the mark after pre-lamination. After the pre-lamination is qualified, the handle (2) and the printed circuit board (1) are pre-pressed.
7. The method for uncovering the sealed cavity of a printed circuit board according to claim 6, characterized in that: In step S32, the alignment mark includes an alignment center line, an offset upper line and an offset lower line, and the interval between the offset upper line and the offset lower line and the alignment center line is 0.2 mm.
8. The method for uncovering the sealed cavity of a printed circuit board according to claim 6, characterized in that: In step S31, the window length of the window opening fixture is 0.05-0.1 mm greater than the single side length of the handle (2).
9. The method for uncovering the sealed cavity of a printed circuit board according to claim 6, characterized in that: In step S32, the pre-pressing temperature is 150-180°C, the pre-pressing pressure is 3-10kg, and the pre-pressing time is 10-30S.
10. The method for uncovering the sealed cavity of a printed circuit board according to claim 1, characterized in that: In step S4, the pressing temperature is 150-170° C., the pressing time is 30-80 min, and the pressing pressure is 100-300 PSI.