Circuit board, transparent display screen and manufacturing method thereof

Abstract

The invention discloses a circuit board, a transparent display screen and a manufacturing method thereof, and the circuit board comprises a light-transmitting film, a circuit layer, glue, and a cover film. The circuit layer is bonded on one surface of the light-transmitting film through glue, the circuit layer comprises a plurality of groups of circuit units, and every two adjacent groups of circuit units are spaced to form vacancies; the covering film is combined on the light-transmitting film and the circuit layer, the covering film or the light-transmitting film is provided with a bonding pad window so as to expose the circuit layer to form a bonding pad, and the covering film is broken at the vacant position, so that the covering films on the two adjacent circuit units are discontinuous; or, the circuit board comprises the light-transmitting film, the circuit layer and the glue, and does not comprise the covering film; the circuit layer is combined on one side of the light-transmitting film through glue, glue is arranged at the position with a circuit on the light-transmitting film, and no glue is arranged at all or part of the position without the circuit; the circuit board is a bare circuit board, or solder resist ink is arranged on the circuit layer. The light transmittance of the transparent display screen is improved, and the manufacturing cost of the transparent display screen can be greatly reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of transparent display screens, in particular to a circuit board, a transparent display screen and a manufacturing method thereof. Background Art

[0002] There are two types of flexible circuit boards available today. One is a three-layer structure consisting of a PI or PET film layer, an adhesive layer, and a circuit layer. The circuit layer is bonded to the film via the adhesive layer, and the film layer is also covered with adhesive. The other is a PI or PET film layer and a circuit layer, with the circuit layer directly bonded to the film layer, leaving the film layer completely adhesive-free. The former, which is a circuit board with adhesive, has high costs because the adhesive covers the entire film surface, leaving only areas without circuitry. The latter, which is a circuit board without adhesive, is technically difficult to manufacture and requires significant equipment investment, resulting in high costs and low industry adoption.

[0003] Transparent displays remain transparent or translucent in areas without metal wiring or LEDs, whether lit or unlit. When attached to glass, transparent displays block only a portion of the light, rather than all, and therefore have a significant market demand.

[0004] Transparent flexible display screens are made by welding LED lamp beads on transparent flexible circuit boards. Transparent flexible boards are made of translucent film, glue and metal foil or / and metal wire. Since metal blocks light, the transmittance of the transparent circuit board is determined by the percentage of area occupied by the metal. The smaller the area occupied by the metal, the greater the transmittance. The area without metal blocking the light is the light-transmitting area. The light-transmitting area also has transparency requirements. The transparency depends on the film material and the glue material. The film material is generally PET film, which has high transparency and can withstand low-temperature soldering of 200 degrees. It is also resistant to yellowing during use. The glue must meet the requirements of being transparent, resistant to soldering temperatures of 200 degrees, and resistant to yellowing. The cost of glue that meets these requirements is very high, which makes the cost of glue used in transparent flexible boards very high, resulting in a high production cost of transparent flexible display screens, hindering the large-scale promotion and popularization of transparent flexible display screens.

[0005] To this end, it is necessary to improve and optimize the existing transparent display screens. Summary of the Invention

[0006] The present invention aims to solve at least one of the problems in the prior art. To this end, the present invention provides a circuit board, a transparent display screen, and a method for manufacturing the same, which not only improves the light transmittance of the transparent display screen but also significantly reduces the manufacturing cost of the transparent display screen.

[0007] The technical solution adopted by the present invention to solve its technical problem is:

[0008] In a first aspect, an embodiment of the present invention provides a method for manufacturing a circuit board, comprising:

[0009] A. Prepare two rolls of light-transmitting film with adhesive, wherein the adhesive on the light-transmitting film is continuous adhesive or spaced adhesive, and the adhesive on the light-transmitting film is light-transmitting adhesive or opaque adhesive; adhere metal foil to the surface of the light-transmitting film to obtain two rolls of metal-clad plates;

[0010] B. Use die-cutting method to make circuits on the metal clad plate on a multi-station die-cutting machine to obtain two rolls of bare circuit boards;

[0011] C. Prepare a roll of cover film with adhesive, use die-cutting to make pad windows on the cover film to form a cover film with pad windows, and cut the cover film with pad windows into multiple strips to form multiple film strips with adhesive;

[0012] D. After the slit covering film, the film strips at odd-numbered positions are attached to one roll of bare circuit boards, and the film strips at even-numbered positions are attached to the other roll of bare circuit boards, thereby obtaining two rolls of circuit boards.

[0013] In a first aspect, an embodiment of the present invention further provides another circuit board manufacturing method, comprising:

[0014] A. Prepare two rolls of transparent film with adhesive, where the adhesive on the transparent film is continuous adhesive or spaced adhesive, and the adhesive on the transparent film is transparent adhesive or opaque adhesive; use a die-cutting method to make solder pad windows on the transparent film, forming two rolls of transparent film with solder pad windows;

[0015] B. Paste metal foil on the light-transmitting film with the pad window to obtain two rolls of metal-clad plates, and use the die-cutting method to produce circuits on the metal-clad plates on a multi-station die-cutting machine to obtain two rolls of bare circuit boards;

[0016] C. preparing a roll of adhesive covering film, and cutting the covering film into multiple strips on the multi-station die-cutting machine to form multiple adhesive film strips;

[0017] D. After the slit covering film, the film strips at odd-numbered positions are attached to one roll of bare circuit boards, and the film strips at even-numbered positions are attached to the other roll of bare circuit boards, thereby obtaining two rolls of circuit boards.

[0018] In a first aspect, an embodiment of the present invention provides another method for manufacturing a circuit board, comprising:

[0019] A. Prepare a roll of transparent film with adhesive. The adhesive on the transparent film is transparent adhesive or opaque adhesive. The adhesive on the transparent film is in strips, and there are multiple strips. There are gaps between adjacent strips of adhesive. Adjacent strips of adhesive are discontinuous or continuous in some positions.

[0020] B. Pasting the metal foil onto the adhesive strip, and forming circuits using die-cutting, etching, or laser engraving, so that the adhesive strip has circuits, thereby obtaining a bare circuit board, and leaving no adhesive on all or part of the transparent film where no circuits are present;

[0021] C. A solder resist layer is formed on the surface of the circuit, wherein the solder resist layer is solder resist ink; or, no solder resist layer is formed on the surface of the circuit, and the bare circuit board can be used directly.

[0022] Optionally, in step A, a glue is printed on the light-transmitting film. Specifically, a screen printing stencil or gravure template is designed according to the circuit design, and the glue is printed on the light-transmitting film using a screen printing machine or gravure printing machine to form the circuit shape.

[0023] In step B, after drying the solvent, the metal foil is bonded to the glue; etching-resistant circuit ink is printed, and the circuit ink corresponds to the position of the glue. After etching, the etching-resistant ink is removed to form the circuit; alternatively, the metal foil is die-cut with a die-cutting machine, and the unnecessary metal foil is torn off and removed. The remaining metal foil forms the circuit, and there is no glue on all or part of the transparent film where there is no circuit.

[0024] Optionally, the metal foil is copper foil, copper-aluminum composite foil or aluminum foil.

[0025] Optionally, the light-transmitting film is made of light-transmitting PET film.

[0026] Optionally, the circuit board obtained by the method described in any embodiment of the first aspect above is a circuit board with a length greater than 2 meters. Multiple connecting circuit boards can be glued on the circuit board to obtain a circuit board with multiple connecting circuit boards. The distance between two adjacent connecting circuit boards is m, and m≥10 cm.

[0027] In a second aspect, an embodiment of the present invention provides a method for manufacturing a transparent display screen, comprising:

[0028] E. Printing solder paste on the circuit board with the connecting circuit board obtained by the above-mentioned manufacturing method, which can be printed on the connecting circuit board at the same time as the solder paste is printed, SMT sealing the LED lamp beads with built-in control chips and light-emitting chips, reflow soldering to form a long roll of flexible display semi-finished products, and connecting the circuit boards to form welding conduction;

[0029] F. On the semi-finished flexible display screen, the LED lamp beads are cut into the required length at the cutting position of each row, or the LED lamp beads are cut into the required length at the position of the connecting circuit board to make a transparent display screen, wherein the connecting circuit board is used to connect to the controller and / or power supply.

[0030] In a third aspect, an embodiment of the present invention provides a circuit board comprising a light-transmitting film, a circuit layer, and glue, and further comprising a cover film; the circuit layer is bonded to one side of the light-transmitting film by glue, the circuit layer comprising multiple groups of circuit units, with spaces formed between adjacent groups of circuit units; the cover film is bonded to the light-transmitting film and the circuit layer, a pad window is provided on the cover film or the light-transmitting film to expose the circuit layer to form a pad, and the cover film is disconnected at the space, such that the cover films on the two adjacent groups of circuit units are discontinuous;

[0031] Alternatively, it includes a light-transmitting film, a circuit layer and glue, but does not include a covering film; the circuit layer is bonded to one side of the light-transmitting film by glue, and on the light-transmitting film, there is glue at the position where the circuit is present, and there is no glue at all or part of the position where there is no circuit; the circuit board is a bare circuit board, or solder resist ink is provided on the circuit layer.

[0032] Optionally, with the covering film, some of the vacancies have glue, the glue in the vacancies is discontinuous or partially continuous, and the glue is translucent glue or opaque glue; or, with the covering film, all of the vacancies have glue, and the glue is translucent glue; or, without the covering film, the glue is translucent glue or opaque glue.

[0033] Optionally, the light-transmitting film is a light-transmitting PET film.

[0034] Optionally, there is no circuit layer on the other side of the light-transmitting film; or, a circuit layer is provided on the other side of the light-transmitting film, and the circuit layers on the front and back sides of the light-transmitting film are arranged opposite to each other and are conductive.

[0035] Optionally, the circuit layer provided on the other side of the light-transmitting film includes positive and negative main circuits.

[0036] Optionally, the circuit board is a circuit board with a length greater than 2 meters, and multiple connecting circuit boards can be glued on the circuit board to obtain a circuit board with multiple connecting circuit boards, and the distance between two adjacent connecting circuit boards is m, and m≥10 cm.

[0037] Optionally, the line width of the circuit layer is greater than, equal to, or less than the width of the glue bonding the circuit.

[0038] Optionally, there is solder resist ink, the solder resist ink and the line overlap, the width of the solder resist ink is relative to the width of the line combined with the ink, and the ink width is greater than, equal to, or less than the line width.

[0039] In a fourth aspect, an embodiment of the present invention provides a transparent display screen, comprising a circuit board as described in any one of the embodiments of the third aspect above, wherein LED lamp beads are welded on at least some of the pads, and connecting wires or connecting circuit boards are welded on one end or both ends of the display screen, wherein the connecting wires or connecting circuit boards are used to connect to a controller and / or a power supply; or, there are no connecting wires and connecting circuit boards on the display screen, and connecting pads are provided on the circuit board, and the connecting pads are used to connect to a controller and / or a power supply.

[0040] Optionally, the display screen has a light-emitting surface, and light-transmitting glue is provided on the light-emitting surface.

[0041] The present invention has at least one of the following beneficial effects: in an embodiment of the present invention, for a double-layer circuit board, the covering film is disconnected at the empty position between two adjacent groups of circuit units, so that the covering films on the two adjacent groups of circuit units are discontinuous, and the solder pad window is set on the light-transmitting film or on the covering film, abandoning the structure in the prior art in which both layers of film are continuous full-surface light-transmitting films, reducing and saving the use of covering film, improving the transmittance of the display screen, and reducing the weight of the display screen; in addition, for the structure in which the glue in the empty position is discontinuous or partially continuous, the amount of glue used is reduced and saved at the same time, further improving the transmittance of the display screen and further reducing the weight of the display screen.

[0042] In the embodiment of the present invention, for a single-layer circuit board, glue is provided at positions where there are circuits on the transparent film, and no glue is provided at all or part of positions where there are no circuits; the circuit board is a bare circuit board, or solder resist ink is provided on the circuit layer, thereby abandoning the structure of continuous glue on the entire surface in the prior art, reducing and saving the amount of glue used, improving the transmittance of the display screen, and reducing the weight of the display screen. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] Figure 1 1 is a schematic diagram of a planar structure in which the glue on the light-transmitting film is a spaced glue in an embodiment of the present invention;

[0044] Figure 2 yes Figure 1 a cross-sectional view of the structure shown;

[0045] Figure 3 1 is a schematic diagram of a planar structure in which the adhesive on the light-transmitting film is continuous and full-surface adhesive in an embodiment of the present invention;

[0046] Figure 4 yes Figure 3 a cross-sectional view of the structure shown;

[0047] Figure 5 This is a schematic diagram of the planar structure of three groups of circuit units combined on a light-transmitting film in an embodiment of the present invention (the glue on the light-transmitting film is spaced apart, and the circuit units are disconnected and not connected);

[0048] Figure 6 yes Figure 5 Schematic diagram of the planar structure when the structure shown is combined with a covering film (the covering film is disconnected at the vacant position, so that the covering films on two adjacent groups of circuit units are discontinuous);

[0049] Figure 7 yes Figure 6 The structure shown is a schematic diagram of the planar structure of the display screen after the lamp beads are welded;

[0050] Figure 8 yes Figure 6 Schematic diagram of the cross-sectional structure of AA;

[0051] Figure 9 2 is a schematic diagram of the cross-sectional structure of a display screen circuit board when all the empty positions are filled with glue in an embodiment of the present invention (the covering film is disconnected at the empty positions, so that the covering films on two adjacent groups of circuit units are discontinuous, and the pad windows are provided on the covering film);

[0052] Figure 10 Schematic diagram of the cross-sectional structure of a display screen circuit board in an embodiment of the present invention in which the covering film is disconnected at the vacant position and the covering films on two adjacent groups of circuit units are discontinuous (glue is present at some positions in the vacant position, the glue in the vacant position is discontinuous, and the pad window is provided on the light-transmitting film);

[0053] Figure 11 2 is a schematic diagram of the cross-sectional structure of a display screen circuit board in an embodiment of the present invention in which the covering film is disconnected at the vacant position and the covering films on two adjacent groups of circuit units are discontinuous (all positions in the vacant position have glue, and the pad window is provided on the light-transmitting film);

[0054] Figure 12 Schematic diagram of the cross-sectional structure of a single-layer film display screen circuit board according to an embodiment of the present invention (some positions in the vacant spaces have glue, the glue in the vacant spaces is discontinuous, and there is no solder resist ink);

[0055] Figure 13 Schematic diagram of the cross-sectional structure of a single-layer film display screen circuit board according to an embodiment of the present invention (some positions in the vacant spaces have glue, the glue in the vacant spaces is discontinuous, and there is solder resist ink);

[0056] Figure 14 yes Figure 13 The structure shown is a schematic diagram of the structure with positive and negative main circuits on the back;

[0057] Figure 15 This is a schematic diagram of a planar structure in which glue having the same shape as a circuit is printed on a light-transmitting film according to an embodiment of the present invention;

[0058] Figure 16 yes Figure 15 Schematic diagram of the planar structure of a bare circuit board with circuits made on a transparent film with glue (the shape of the circuit is consistent with the shape of the glue);

[0059] Figure 17 1 is a schematic diagram of a planar structure in which a connecting circuit board is provided on the upper end of the circuit board in an embodiment of the present invention (the connecting circuit board connects the three circuit units);

[0060] Figure 18 1 is a schematic diagram of a planar structure in which a connection circuit board is provided at both the upper and lower ends of the circuit board in an embodiment of the present invention (the connection circuit board connects the three circuit units);

[0061] Figure 19 yes Figure 18 The structure shown is a schematic diagram of the planar structure of the display screen when LED lamp beads are welded;

[0062] Figure 20 yes Figure 18 Schematic diagram of the cross-section structure when the circuit boards are connected and overlapped (partial);

[0063] Figure 21 yes Figure 19 Schematic diagram of the cross-sectional structure when the circuit boards are connected at the overlapping position (partial, the circuit boards are connected by soldering);

[0064] Figure 22 1 is a schematic diagram of the planar structure of the adhesive printed on the light-transmitting film when first connected in an embodiment of the present invention;

[0065] Figure 23 yes Figure 22 The structure shown is a schematic diagram of the bare circuit board plan when the circuit is made (having 5 circuit units, and the 5 circuit units are connected);

[0066] Figure 24 yes Figure 23 The structure shown is a schematic diagram of the planar structure of the circuit board after the solder mask ink is made (a connection pad is provided at the lower end);

[0067] Figure 25-27 Schematic diagrams of three cross-sectional structures of line width and glue width in an embodiment of the present invention;

[0068] Figure 28 It is a schematic diagram of the structure when two circuit boards are spliced ​​into a long board by connecting the circuit boards;

[0069] Figure 29-Figure 31 Schematic diagrams of three cross-sectional structures of line width and ink width in an embodiment of the present invention;

[0070] Description of Figure Numbers:

[0071] 1-light-transmitting film, 2-glue, 3-cover film, 4-pad window, 5-LED lamp bead, 6-solder resist ink, 7-main circuit, 8-connecting circuit board, 9-tin, 10-circuit unit, 11-circuit layer, c-vacant space, e-connecting pad. DETAILED DESCRIPTION

[0072] To make the purpose, technical solutions and advantages of the present invention more clearly understood, the embodiments of the present invention will be described in detail below with reference to the accompanying drawings. It should be noted that the embodiments and features in the embodiments described below can be combined with each other in any manner unless there is any conflict.

[0073] The following provides many different embodiments or examples for realizing the structure of the present invention.

[0074] See also Figure 1-Figure 28 A first embodiment of the present invention provides a method for manufacturing a circuit board, comprising:

[0075] A. Prepare two rolls of transparent film 1 with adhesive 2, where the adhesive 2 on the transparent film 1 is continuous; or, see Figure 1 and Figure 2 As shown, the glue 2 on the transparent film 1 is a spaced transparent glue, thereby eliminating part of the glue, saving the amount of glue, and also helping to improve the transmittance of the circuit board; a metal foil is pasted on the surface of the transparent film 1, specifically copper foil or copper-aluminum composite foil or aluminum foil, to obtain two rolls of metal-coated plates; the glue on the transparent film 1 includes three situations: ①, the entire surface of the side of the transparent film 1 used for bonding the metal foil has glue 2, so the glue 2 on the transparent film 1 is a continuous full-surface glue, in this case, the glue is a transparent glue (fully transparent glue or semi-transparent glue); ②, the side of the transparent film 1 used for bonding the metal foil has a plurality of spaced glues, such as Figure 1 As shown, there are gaps and discontinuities between the glues. In this case, the glue 2 can be a light-transmitting glue or an opaque glue. ③. The light-transmitting film 1 has a plurality of gaps between the glues on one side for bonding the metal foil. Figure 1 There are gaps as shown, but there are thin glue strips (not shown) in the gaps to connect the glues at intervals, so that the glue forms a continuous glue. At this time, the glue 2 can be a light-transmitting glue or an opaque glue.

[0076] B. Use die-cutting method to make circuits on metal clad plate on multi-station die-cutting machine to obtain two rolls of bare circuit boards. Figure 5 As shown, the bare circuit board has three groups of circuit units 10. In actual products, the number of groups of circuit units may be greater.

[0077] C. Prepare a roll of adhesive cover film 3, which can be a translucent PET film or an opaque film, with adhesive applied to the entire surface of the cover film 3. Use die-cutting to create solder pad windows on the cover film 3 to form a cover film with solder pad windows. Cut the cover film with solder pad windows into multiple strips to form multiple adhesive film strips.

[0078] D. The film strips at odd-numbered positions of the slit cover film 3 are attached to one roll of bare circuit boards, and the film strips at even-numbered positions are attached to the other roll of bare circuit boards, to obtain two rolls of circuit boards. Specifically, the film strips at positions 1, 3, 5, etc. of the slit cover film are attached to one roll of bare circuit boards obtained in step B, and the film strips at positions 2, 4, 6, etc. are attached to the other roll of bare circuit boards obtained in step B, to obtain two rolls of circuit boards, as shown in FIG. Figure 6 As shown; In the prior art, the cover film 3 is not cut, but directly bonded to a roll of bare circuit board. Figure 6 In the embodiment, position a on the circuit board is not covered with a film, while in the prior art circuit boards, the corresponding position a is covered with a film. Obviously, compared with the prior art, the present application breaks the covering film 3 at the empty position c between two adjacent groups of circuit units 10, making the covering film 3 on the two adjacent groups of circuit units 10 discontinuous, saving the amount of covering film used, improving the light transmittance of the display screen, and reducing the weight of the display screen. For position a, when the glue on the transparent film is continuous, position a has no covering film, and some or all of the positions have glue, such as Figure 9 As shown; when the glue on the transparent film is selected as the spaced transparent glue, there is no covering film at position a and no transparent glue, such as Figure 8 The method described in this embodiment also has the following advantages: die-cutting is highly automated, efficient, low-cost, and environmentally friendly for circuit board processing (existing display panels are all produced by etching); the display circuit boards are produced in rolls, which is highly efficient and can be cut to the desired length by the user; and each cut display circuit board is not spliced ​​together from multiple sections (existing techniques use multiple sections, which can break easily at the seams and allow water to seep in from the back).

[0079] The first embodiment of the present invention further provides a second circuit board manufacturing method, comprising:

[0080] A. Prepare two rolls of transparent film with adhesive, where the adhesive on the transparent film is continuous adhesive; or, the adhesive on the transparent film is spaced adhesive; use die-cutting to make solder pad windows on the transparent film to form two rolls of transparent film with solder pad windows; the adhesive on the transparent film also includes three situations, which are specifically the same as described in the first circuit board manufacturing method mentioned above.

[0081] B. Pasting metal foil, specifically copper foil, copper-aluminum composite foil or aluminum foil, on the light-transmitting film with the pad window to obtain two rolls of clad metal sheets. Using a multi-station die-cutting machine, die-cutting is used to produce circuits on the clad metal sheets to obtain two rolls of bare circuit boards.

[0082] C. preparing a roll of adhesive covering film, and cutting the covering film into multiple strips on the multi-station die-cutting machine to form multiple adhesive film strips;

[0083] D. Paste the film strips at odd-numbered positions on one roll of bare circuit boards and the film strips at even-numbered positions on the other roll of bare circuit boards to obtain two rolls of circuit boards. Specifically, paste the film strips at positions 1, 3, 5, etc. on one roll of bare circuit boards obtained in step B, and paste the film strips at positions 2, 4, 6, etc. on the other roll of bare circuit boards obtained in step B to obtain two rolls of circuit boards. Figure 10 or Figure 11 As shown; In the prior art, the cover film is not cut, but directly bonded to a roll of bare circuit board. Figure 10 In the embodiment, position b on the circuit board is without a covering film, whereas in the prior art circuit board, the corresponding position b is provided with a covering film. Obviously, compared with the prior art, the present application breaks the covering film at the empty position between two adjacent groups of circuit units 10, making the covering film 3 on the two adjacent groups of circuit units 10 discontinuous, thus saving the amount of covering film used, improving the light transmittance of the display screen, and reducing the weight of the display screen. For position b, when the glue on the transparent film is continuous, position b is without a covering film, and some or all of the positions are provided with glue, such as Figure 11 As shown; when the glue on the transparent film is selected as the spacer glue, there is no covering film at position b and no transparent glue, such as Figure 10 The method described in this embodiment also has the following advantages: die-cutting is highly automated, efficient, low-cost, and environmentally friendly for circuit board processing (existing display panels are all produced by etching); the display circuit boards are produced in rolls, which is highly efficient and can be cut to the desired length by the user; and each cut display circuit board is not spliced ​​together from multiple sections (existing techniques use multiple sections, which can break easily at the seams and allow water to seep in from the back).

[0084] The first embodiment of the present invention further provides a third circuit board manufacturing method, comprising:

[0085] A. Prepare a roll of transparent film with adhesive. The adhesive on the transparent film can be transparent adhesive or opaque adhesive. The adhesive on the transparent film is in strips and there are multiple strips. There are intervals between adjacent strips of transparent adhesive, including disconnection and discontinuity between adjacent strips of adhesive. The structure of the transparent film with adhesive 1 can be as follows: Figure 1 and Figure 2 As shown; also includes adjacent strips of glue that are spaced apart but continuous, such as Figure 22 shown.

[0086] B. Use copper foil or copper-aluminum composite foil or aluminum foil to stick on the strip adhesive, use die cutting method or etching method or laser engraving method to make circuits, so that the strip adhesive has circuits to obtain a bare circuit board; there is no adhesive on all positions where there are no circuits on the transparent film, such as Figure 23 Alternatively, there is no glue at some locations on the transparent film where there are no circuits, and glue at some locations, such as Figure 12 shown.

[0087] C. Make a solder resist layer on the surface of the circuit. The solder resist layer is solder resist ink. Figure 13 Alternatively, no solder mask is made on the surface of the circuit, and the bare circuit board can be used directly. Figure 12 As shown. Figure 12 and Figure 13 It can be seen that the glue between the two groups of line units 10 is discontinuous, or Figure 23 It can be seen that the glue portion between the two groups of circuit units 10 is continuous, which reduces the use of glue, is beneficial to improving the light transmittance of the circuit board, reducing costs and reducing weight.

[0088] In the above three embodiments, the material of the light-transmitting film is a light-transmitting PET film.

[0089] In the third circuit board manufacturing method described above, the embodiment of the present invention provides a more detailed manufacturing method, specifically: in step A, printing glue on the light-transmitting film, specifically, designing a screen printing screen or gravure template for printing glue according to the circuit design, and printing glue on the light-transmitting film using a screen printing machine or gravure printing machine to print into the shape of the circuit, for details, see Figure 15 or Figure 22 As shown; in step B, after drying the solvent, the metal foil is bonded to the glue; printing the etching-resistant circuit ink, the circuit ink corresponds to the position of the glue, and after etching, the etching-resistant ink is removed to form a circuit, as shown Figure 16 or Figure 23 Alternatively, the metal foil is cut with a die-cutting machine, and the unnecessary metal foil is removed by tearing off, and the remaining metal foil forms a circuit, such as Figure 16 The obtained circuit board has no adhesive at all locations on the transparent film where there are no circuits; depending on the printing of the adhesive, there may also be no adhesive at some locations on the transparent film where there are no circuits, and adhesive at some locations.

[0090] In the above method embodiment, a circuit board is made into a circuit board with a length greater than 2 meters. A plurality of connecting circuit boards 8 can be glued on the circuit board to obtain a circuit board having a plurality of connecting circuit boards 8. The distance between two adjacent connecting circuit boards is m, where m is ≥ 10 cm. By connecting the circuit boards 8, the circuit boards can be spliced ​​together to form a long circuit board for use, such as Figure 28A second embodiment of the present invention provides a method for manufacturing a transparent display screen, comprising:

[0091] E. Print solder paste on the circuit board obtained by the manufacturing method of the embodiment with the connected circuit board. Print solder paste on the connected circuit board at the same time. SMT seal the LED lamp beads with built-in control chip and light-emitting chip. Reflow soldering is made into a long roll of flexible display semi-finished product. Connect the circuit boards to form welding conduction. For details, see Figure 21 As shown, the two are connected through tin 9.

[0092] F. On the semi-finished flexible display screen, the LED lamp beads are cut into the required length at the cutting position of each row, or the transparent display screen is made by cutting the LED lamp beads into the required length at the position of the connection circuit board, wherein the connection circuit board is used to connect to the controller and / or power supply.

[0093] A third embodiment of the present invention provides a circuit board, comprising:

[0094] Light-transmitting film 1, which is a light-transmitting PET film;

[0095] The circuit layer 11 is bonded to one side of the light-transmitting film 1 by means of glue 2. The circuit layer includes a plurality of circuit units 10. There is a gap between two adjacent circuit units 10 to form a space c. Figure 8 、 Figure 10 or Figure 12 、 Figure 16 、 Figure 23 As shown;

[0096] See Figure 8 or Figure 9 As shown, embodiment 1: also includes a covering film 3, which can be specifically a translucent PET film. The covering film 3 is combined with the translucent film 1 and the circuit layer 11, and the specific combining method is to fix it by adhesive bonding. A pad window 4 is provided on the covering film 3 to expose the circuit layer 11 to form a pad. The covering film 3 is disconnected at the position of the vacancy c, so that the covering films 3 on the two adjacent groups of circuit units 10 are discontinuous; thus, in the vacancy c between the two adjacent groups of circuit units 10, due to the discontinuity of the covering film 3, part of the position in the vacancy c does not have the covering film 3, that is, the use of part of the covering film 3 is omitted, which obviously reduces the cost and reduces the weight; and because part of the position in the vacancy c does not have the covering film 3, compared with the existing technology in which the corresponding position has the covering film 3, the transmittance of the display circuit board is obviously improved (because even if the covering film 3 is a translucent film, it can transmit light, but the transmittance cannot be 100%).

[0097] See Figure 10 or Figure 11As shown, embodiment 2: further includes a covering film 3, which is combined on the light-transmitting film 1 and the circuit layer 11, and a pad window 4 is provided on the light-transmitting film 1 to expose the circuit 11 to form a pad; the covering film 3 is disconnected at the position of the vacancy c, so that the covering films 3 on the two adjacent groups of circuit units 10 are discontinuous; thus, in the vacancy c between the two adjacent groups of circuit units 10, due to the discontinuity of the covering film 3, part of the position in the vacancy c does not have the covering film 3, that is, the use of part of the covering film 3 is omitted, which obviously reduces the cost and reduces the weight; and because part of the position in the vacancy c does not have the covering film 3, compared with the existing technology in which the corresponding position has the covering film 3, the transmittance of the display circuit board is obviously improved (because even if the covering film 3 is a light-transmitting film, it can transmit light, but the transmittance cannot be 100%).

[0098] The third embodiment of the present invention also provides a third circuit board, embodiment 3: the circuit board does not have a covering film, the circuit layer 11 is combined with the surface of the transparent film 1 by glue 2, and the transparent film 1 has glue 2 at the position where the circuit is located, and no glue at all positions where there is no circuit (such as Figure 16 As shown), or there is no glue in some places (as shown Figure 12 shown or Figure 13 ); the circuit board is a bare circuit board (such as Figure 12 As shown), or the circuit layer is provided with solder resist ink (as shown Figure 13 shown).

[0099] See Figure 8 or Figure 10 As shown, with the covering film 3, in some embodiments, some positions in the vacant space c have glue, and the glue in the vacant space is discontinuous or partially continuous. In this case, the glue can be light-transmitting glue or opaque glue. This structure not only reduces and saves the use of the covering film 3, but also reduces and saves the use of glue, further reduces the production cost of the circuit board, and further improves the light transmittance of the circuit board. For details, see Figure 9 or Figure 11 As shown, in other embodiments, with the covering film 3, all positions in the vacant space are provided with glue, in which case the glue is a light-transmitting glue; see Figure 12 or Figure 13 As shown, in other embodiments, there is no covering film 3. In this case, the glue can be a light-transmitting glue or an opaque glue.

[0100] In some embodiments of the present invention, the other side of the light-transmitting film 1 has no circuit layer, and the circuit board is a single-layer circuit board. Figure 8 or Figure 9 or Figure 12 or Figure 13 As shown, the front side of the light-transmitting film 1 has a circuit layer 11, and the back side has no circuit layer; Figure 10or Figure 11 As shown, the back of the light-transmitting film has a circuit layer 11, and the front has no circuit layer; in other embodiments, see Figure 14 As shown, a circuit layer is provided on the other side of the light-transmitting film 1, and the circuit layers on the front and back sides of the light-transmitting film 1 are arranged opposite to each other and are connected, that is, the circuit board is a double-layer circuit board.

[0101] See also Figure 14 As shown, in some embodiments of the present invention, the circuit layer arranged on the other side of the light-transmitting film 1 contains positive and negative main circuits 7. The arrangement of the positive and negative main circuits 7 enables the circuit board to have a larger current load.

[0102] See Figure 18 、 28 As shown, the circuit board is a circuit board with a length greater than 2 meters. Multiple connecting circuit boards 8 can be glued on the circuit board to obtain a circuit board with multiple connecting circuit boards 8. The distance between two adjacent connecting circuit boards 8 is m, and m≥10 cm.

[0103] For details about line width and glue width, see Figure 25-27 As shown, the line width of the circuit layer is greater than, equal to, or less than the width of the glue bonding the circuit.

[0104] See Figure 29-Figure 31 The solder resist ink 6 is provided, the solder resist ink 6 overlaps with the circuit, and the width of the solder resist ink 6 is greater than, equal to, or less than the circuit width relative to the circuit width combined with the ink.

[0105] See Figure 7 As shown, an embodiment of the present invention further provides a transparent display screen, comprising a circuit board as described in any of the above embodiments, wherein at least part of the pads are welded with LED lamp beads 5, and one end or both ends of the display screen are welded with a connecting wire or a connecting circuit board (such as Figure 18 As shown), wherein the connecting wire or connecting circuit board 8 is used to connect the controller and / or the power supply. In other embodiments, or, there are no connecting wires and connecting circuit boards on the display screen, and the circuit board is provided with connecting pads e (such as Figure 24 The connection pads are used to connect to the controller and / or power supply.

[0106] In some embodiments of the present invention, the display screen has a light-emitting surface, and a light-transmitting adhesive is provided on the light-emitting surface.

[0107] The embodiments of the present invention are described in detail above with reference to the accompanying drawings. However, the present invention is not limited to the above embodiments. Various changes can be made within the scope of knowledge possessed by ordinary technicians in the relevant technical field without departing from the scope of the present invention.

Claims

1. A method for manufacturing a circuit board, characterized in that: include: A. Prepare two rolls of light-transmitting film with adhesive, wherein the adhesive on the light-transmitting film is continuous adhesive or spaced adhesive, and the adhesive on the light-transmitting film is light-transmitting adhesive or opaque adhesive; adhere metal foil to the surface of the light-transmitting film to obtain two rolls of metal-clad plates; B. Use die-cutting method to make circuits on the metal clad plate on a multi-station die-cutting machine to obtain two rolls of bare circuit boards; C. Prepare a roll of cover film with adhesive, use die-cutting to make pad windows on the cover film to form a cover film with pad windows, and cut the cover film with pad windows into multiple strips to form multiple film strips with adhesive; D. After the slit covering film, the film strips at odd-numbered positions are attached to one roll of bare circuit boards, and the film strips at even-numbered positions are attached to the other roll of bare circuit boards, thereby obtaining two rolls of circuit boards.

2. A method for manufacturing a circuit board, characterized in that: include: A. Prepare two rolls of transparent film with adhesive, where the adhesive on the transparent film is continuous adhesive or spaced adhesive, and the adhesive on the transparent film is transparent adhesive or opaque adhesive; use a die-cutting method to make solder pad windows on the transparent film, forming two rolls of transparent film with solder pad windows; B. Paste metal foil on the light-transmitting film with the pad window to obtain two rolls of metal-clad plates, and use the die-cutting method to produce circuits on the metal-clad plates on a multi-station die-cutting machine to obtain two rolls of bare circuit boards; C. preparing a roll of adhesive covering film, and cutting the covering film into multiple strips on the multi-station die-cutting machine to form multiple adhesive film strips; D. After the slit covering film, the film strips at odd-numbered positions are attached to one roll of bare circuit boards, and the film strips at even-numbered positions are attached to the other roll of bare circuit boards, thereby obtaining two rolls of circuit boards.

3. A method for manufacturing a circuit board, characterized in that: include: A. Prepare a roll of transparent film with adhesive. The adhesive on the transparent film is transparent adhesive or opaque adhesive. The adhesive on the transparent film is in strips, and there are multiple strips. There are gaps between adjacent strips of adhesive. Adjacent strips of adhesive are discontinuous or continuous in some positions. B. Pasting the metal foil onto the adhesive strip, and forming circuits using die-cutting, etching, or laser engraving, so that the adhesive strip has circuits, thereby obtaining a bare circuit board, and leaving no adhesive on all or part of the transparent film where no circuits are present; C. A solder resist layer is formed on the surface of the circuit, wherein the solder resist layer is solder resist ink; or, no solder resist layer is formed on the surface of the circuit, and the bare circuit board can be used directly.

4. A method for manufacturing a circuit board according to claim 3, characterized in that: In step A, printing glue on the light-transmitting film. Specifically, according to the circuit design, a screen printing stencil or gravure template for printing glue is designed, and the glue is printed on the light-transmitting film using a screen printing machine or gravure printing machine to print into the shape of the circuit; In step B, after drying the solvent, the metal foil is bonded to the glue; Printing anti-etching circuit ink, the circuit ink corresponds to the position of the glue, and after etching, the anti-etching ink is removed to form the circuit; Alternatively, the metal foil is die-cut with a die-cutting machine, and the unnecessary metal foil is torn off and removed, and the remaining metal foil forms a circuit, and there is no glue on all or part of the transparent film where there is no circuit.

5. A method for manufacturing a circuit board according to any one of claims 1 to 4, characterized in that: The metal foil is copper foil, copper-aluminum composite foil or aluminum foil.

6. A method for manufacturing a circuit board according to any one of claims 1 to 4, characterized in that: The material of the light-transmitting film is light-transmitting PET film.

7. A method for manufacturing a circuit board according to any one of claims 1 to 4, characterized in that: The circuit board obtained by the method described in any one of claims 1 to 4 above is a circuit board having a length greater than 2 meters. Multiple connecting circuit boards can be glued on the circuit board to obtain a circuit board having multiple connecting circuit boards. The distance between two adjacent connecting circuit boards is m, and the m is ≥ 10 cm.

8. A method for manufacturing a transparent display screen, characterized in that: include: E. Printing solder paste on the circuit board obtained by the method of claim 7 above, and printing the solder paste on the connecting circuit board at the same time, SMT sealing the LED lamp beads with built-in control chip and light-emitting chip, reflow soldering to form a long roll of flexible display semi-finished product, and connecting the circuit boards to form welding conduction; F. On the semi-finished flexible display screen, the LED lamp beads are cut into the required length at the cutting position of each row, or the LED lamp beads are cut into the required length at the position of the connecting circuit board to make a transparent display screen, wherein the connecting circuit board is used to connect to the controller and / or power supply.

9. A circuit board, characterized in that: The invention comprises a light-transmitting film, a circuit layer, and glue, and also a covering film; the circuit layer is bonded to one side of the light-transmitting film by glue, the circuit layer comprises multiple groups of circuit units, and two adjacent groups of circuit units are spaced apart to form a gap; the covering film is bonded to the light-transmitting film and the circuit layer, and a pad window is provided on the covering film or the light-transmitting film to expose the circuit layer to form a pad, and the covering film is disconnected at the gap position, so that the covering films on two adjacent groups of circuit units are discontinuous; Alternatively, it includes a light-transmitting film, a circuit layer and glue, but does not include a covering film; the circuit layer is bonded to one side of the light-transmitting film by glue, and on the light-transmitting film, there is glue at the position where the circuit is present, and there is no glue at all or part of the position where there is no circuit; the circuit board is a bare circuit board, or solder resist ink is provided on the circuit layer.

10. A circuit board according to claim 9, characterized in that: With the covering film, some of the vacancies have glue, the glue in the vacancies is discontinuous or partially continuous, and the glue is translucent glue or opaque glue; or, with the covering film, all of the vacancies have glue, and the glue is translucent glue; or, without the covering film, the glue is translucent glue or opaque glue.

11. The circuit board according to claim 9, characterized in that: The light-transmitting film is a light-transmitting PET film.

12. A circuit board according to any one of claims 9 to 11, characterized in that: The other side of the light-transmitting film has no circuit layer; or, the other side of the light-transmitting film is provided with a circuit layer, and the circuit layers on the front and back sides of the light-transmitting film are arranged opposite to each other and form conduction.

13. A circuit board according to claim 12, characterized in that: The circuit layer disposed on the other side of the light-transmitting film includes positive and negative main circuits.

14. The circuit board according to claim 9, characterized in that: The circuit board is a circuit board with a length greater than 2 meters. Multiple connecting circuit boards can be glued on the circuit board to obtain a circuit board with multiple connecting circuit boards. The distance between two adjacent connecting circuit boards is m, and m≥10 cm.

15. The circuit board according to claim 9, characterized in that: The line width of the circuit layer is greater than, equal to, or smaller than the width of the glue bonding the circuit.

16. The circuit board according to claim 9, characterized in that: The solder resist ink is provided, the solder resist ink and the line overlap, the width of the solder resist ink is relative to the width of the line combined with the ink, and the ink width is greater than, equal to, or less than the line width.

17. A transparent display screen, characterized in that: A circuit board comprising any one of claims 9 to 16, wherein LED lamp beads are welded on at least some of the welding pads, and connecting wires or connecting circuit boards are welded on one end or both ends of the display screen, wherein the connecting wires or connecting circuit boards are used to connect to a controller and / or a power supply; or, there are no connecting wires and connecting circuit boards on the display screen, and connecting pads are provided on the circuit board, and the connecting pads are used to connect to a controller and / or a power supply.

18. The transparent display screen according to claim 17, characterized in that: The display screen has a light-emitting surface, and light-transmitting glue is arranged on the light-emitting surface.

Images