Circuit board and lamp strip

Abstract

The utility model discloses a circuit board and a lamp strip, the circuit board comprises main circuits, the main circuits are single-layer main circuits formed by copper-aluminum composite metal or aluminum, or the main circuits are double-layer main circuits formed by aluminum and copper or aluminum and copper-aluminum composite metal, the number of the main circuits is multiple, and the main circuits are arranged at the board edge position of the circuit board. The line widths of at least partial positions of the main line are different; the auxiliary circuit is made of copper or copper-aluminum composite metal, and the auxiliary circuit is located in the middle area of the circuit board; the thickness of part or all of the main circuit is greater than that of the auxiliary circuit; the circuit board comprises a non-metal area without a circuit, and in at least part of the non-metal area, the first insulating layer and the second insulating layer are bonded to clamp the main circuit and the auxiliary circuit. The thickness of a main circuit and a metal-free area are reduced, the load of the circuit board is improved, and wrinkling, large bumps and the like of the circuit board are avoided.

Description

TECHNICAL FIELD

[0001] The utility model relates to the technical field of lamp strip, specifically a circuit board and lamp strip. BACKGROUND

[0002] LED lamp strip is a very popular mass product, and its feature is that cost is king, so the innovation of reducing the cost of the popular mass product is the most important innovation, and in product design, the cost structure must be finely matched, so in the composition design of the lamp strip circuit board, more aluminum is used to replace copper to make the circuit on a circuit board, another feature of the lamp strip circuit board is that there are at least two positive and negative main lines from the head to the tail for connecting the power supply to power the entire LED of the lamp strip, and the circuit board also includes a sub-line for welding the LED to form a series and parallel structure of the LED, wherein the main line loads the entire lamp strip, and the main line requires wider and / or thicker metal, so the amount of metal used for the main line is large, and if copper is used, the cost is too high, so the main line uses aluminum or copper-aluminum composite metal, and the cost can be greatly reduced; because the sub-line is very short and has small load flow, the sub-line can be designed to be thinner and smaller than the main line, so very thin metal can be used; however, the sub-line has a solder pad for welding the LED, in order to have good soldering tin property and low cost, the sub-line is designed to be a very small circuit with very thin copper, and the cost is also relatively low, or the sub-line uses a thin copper-aluminum foil (aluminum surface combined with a layer of copper), and the cost is even lower.

[0003] In order to reduce the manufacturing cost of the circuit board, in the prior art, the main line adopts two parallel conductors of aluminum or copper-clad aluminum to reduce the use of copper in the main line, and aluminum is much cheaper than copper, thereby greatly reducing the manufacturing cost of the circuit board and achieving good market benefits.

[0004] The inventor found in the long-term market research and research and development process that the use of parallel conductors in the main line will cause the following problems:

[0005] ①, see Figure 1.1 illustrated, since the main line is two parallel conductors 1' of equal width (equal width means that the width of each conductor is consistent), the width of each conductor is the same from the head to the tail, and the parallel conductors are designed to be close to the edge of the circuit board, and the distance between the parallel conductors and the component pads on the circuit board must be kept a certain distance a' (at least 0.2mm), and in actual circuit, the distance between the edge of the circuit board and the component pads is limited, and the distance is as small as less than 1mm in many positions, which causes the used parallel conductors to be very narrow, and the parallel conductors are positive and negative main conductors from the head to the tail, and narrow conductors mean small load, which causes the brightness of the tail end of the lamp strip to be much lower than the brightness of the head end (the lamp strip is very long, generally ≥5 meters), and also causes the parallel conductors to heat, which shortens the service life of the LED lamp;

[0006] ②, in order to more scientific cost collocation, parallel wire 1' is all with aluminum wire or copper clad aluminum wire, sub line 2' uses copper foil, in order to cost optimization, will be the line formed by copper foil design as small as possible, the amount of copper is small, thereby the cost is lower, this will cause the area of the upper and lower two kinds of line metal occupies the area of circuit board is small, that is, cause the line to form a large area of no metal area b', only the upper and lower two layers of resin film is bonded together, make the circuit board when SMT soldering, through 200 DEG or more high temperature reflow soldering, in the position of large area no metal support resin film shrinkage is big, cause the circuit board to wrinkle, affect the appearance of the lamp strip;

[0007] ③, refer to the specific Figure 1.2 、 Figure 1.3 As shown in the figure, since the parallel wire is arranged in the small space near the edge of the circuit board, the wire is narrow, so the parallel wire needs to be made thicker to have larger load, so as to meet the requirement that there is no obvious brightness difference at the beginning and end of the lamp strip, but when the parallel wire is too thick, the both sides of the whole circuit board are too thick and the middle part is too thin, so that the circuit board is deformed under high temperature when SMT reflow soldering elements; meanwhile, the too thick parallel wire causes bubbles 3' on the side surface of the parallel wire, and the bubbles are hot expanded to form large bumps 4' when reflow soldering, finally causing the lamp strip product to be scrapped.

[0008] Therefore, it is necessary to improve and optimize the existing circuit board and the like. Content of the utility model

[0009] The utility model aims at solving one of the problems in the prior art at least. To this end, the utility model provides a manufacturing method of a circuit board, a circuit board and a lamp strip, which are beneficial to reducing the thickness of the main line and the non-metal area, improving the load of the circuit board and avoiding the circuit board from wrinkling and forming large bumps.

[0010] The utility model solves the technical problems by adopting the following technical scheme:

[0011] In the first aspect, the utility model embodiment provides a manufacturing method of a circuit board, comprising:

[0012] providing a first insulating film;

[0013] bonding a first metal foil on the first insulating film, using die cutting method to die cut the first metal foil, tearing off the unnecessary metal, and the metal left on the first insulating film forms a first line group, the first line group is multiple, and at least two main lines in the first line group have inconsistent width at least in part;

[0014] providing a second insulating film, bonding a second metal foil on the second insulating film, tearing off the unnecessary metal after die cutting, and the metal left on the second insulating film forms a second line group, and the second line group has multiple sub lines;

[0015] The first insulating film with the first circuit group and the second insulating film with the second circuit group are laminated together so that the first insulating film and the second insulating film are bonded, and the first insulating film and the second insulating film sandwich the first circuit group and the second circuit group;

[0016] The first metal foil is a copper-aluminum composite foil, and the second metal foil is a copper foil; or the first metal foil is an aluminum foil, and the second metal foil is a copper foil or a copper-aluminum composite foil.

[0017] The first insulating film or / and the second insulating film is die-cut to form the pad window by using a die-cutting method.

[0018] Optionally, the first circuit group and the second circuit group partially overlap or do not overlap during lamination; the exposed metal of a single pad window is copper, aluminum, or copper and aluminum; and the exposed metal of each pad window in the plurality of pad windows is the same or different.

[0019] Optionally, the first circuit group and the second circuit group do not overlap during lamination, and the pad window is manufactured by: after the first insulating film is provided, the pad window is manufactured on the first insulating film by using a die-cutting method; or / and, after the second insulating film is provided, the pad window is manufactured on the second insulating film by using a die-cutting method; the first circuit group and the second circuit group partially overlap during lamination, and the pad window is manufactured by: after the first insulating film is provided, the pad window is manufactured on the first insulating film by using a die-cutting method; or / and, the first insulating film with the first circuit group is manufactured by using a die-cutting method, the pad window penetrates the first insulating film, or part of the pad window penetrates the first insulating film and part of the pad window penetrates the metal of the first circuit group; or / and, after the second insulating film is provided, the pad window is manufactured on the second insulating film by using a die-cutting method.

[0020] In a first aspect, another embodiment of the utility model provides a manufacturing method of a circuit board, comprising:

[0021] The first insulating film is provided.

[0022] The first metal foil is bonded on the first insulating film, the first metal foil is die-cut by using a die-cutting method, the unnecessary metal is torn off, the metal remaining on the first insulating film forms the first circuit group, and the first circuit group contains a plurality of first main circuits, and the position width of each first main circuit is inconsistent at least in part.

[0023] The second insulating film is provided, the second metal foil is bonded on the second insulating film, the unnecessary metal is torn off after die-cutting, the metal remaining on the second insulating film forms the second circuit group, and the second circuit group contains a plurality of second main circuits and a plurality of auxiliary circuits.

[0024] The first insulating film with the first circuit group and the second insulating film with the second circuit group are attached together so that the first insulating film and the second insulating film are bonded, and the first insulating film and the second insulating film sandwich the first main circuit, the second main circuit and the auxiliary circuit, and the second main circuit is in contact with the first main circuit in an overlapping manner and is in conduction;

[0025] The first metal foil is an aluminum foil, and the second metal foil is a copper foil or a copper-aluminum composite foil.

[0026] The first insulating film or / and the second insulating film is / are subjected to die cutting to form the pad window.

[0027] Optionally, the pad window is manufactured by using a die cutting method to manufacture the pad window on the first insulating film with the first circuit group, the pad window penetrating the first insulating film, or part of the pad window penetrating the first insulating film and part of the pad window penetrating the first insulating film and the metal of the first circuit group; or / and, after the second insulating film is provided, the pad window is manufactured on the second insulating film by using the die cutting method.

[0028] Optionally, the exposed metal of each pad window is copper, aluminum or copper and aluminum.

[0029] Optionally, the second main circuit is two, arranged on both sides of the auxiliary circuit, the second main circuit extends along the length direction of the circuit board, and the length of the second main circuit is greater than 1 meter.

[0030] The first aspect embodiment of the utility model has at least one of the following beneficial effects: the utility model embodiment forms a first circuit group by die cutting the first metal foil on the first insulating film, the first circuit group has at least two main circuits, the width of each main circuit is inconsistent at least in part, bonds the second metal foil on the second insulating film, forms a second circuit group after die cutting, the second circuit group has multiple secondary circuits, bonds the first insulating film with the first circuit group and the second insulating film with the second circuit group together, so that the first insulating film and the second insulating film are bonded, the first insulating film and the second insulating film clamp the first circuit group and the second circuit group in the middle, wherein the first metal foil is copper-aluminum composite foil, and the second metal foil is copper foil; or the first metal foil is aluminum foil, and the second metal foil is copper foil or copper-aluminum composite foil; or the first metal foil is bonded on the first insulating film, the first circuit group is formed by die cutting the first metal foil using a die cutting method, the first circuit group contains multiple first main circuits, the width of each first main circuit is inconsistent at least in part, the second metal foil is bonded on the second insulating film, the second circuit group is formed after die cutting, the second circuit group contains multiple second main circuits and a plurality of secondary circuits, the first insulating film with the first circuit group and the second insulating film with the second circuit group are bonded together, so that the first insulating film and the second insulating film are bonded, the first insulating film and the second insulating film clamp the first main circuit, the second main circuit and the secondary circuit in the middle, the second main circuit and the first main circuit overlap and contact, wherein the first metal foil is aluminum foil; the second metal foil is copper foil or copper-aluminum composite foil; the setting mode of the main circuit being parallel wires with equal width in the prior art is abandoned, in the embodiment, the width of the main circuit is inconsistent at least in part, so that the main circuit can be set to be wide and narrow, and the width of the main circuit is no longer completely limited by the distance space from the board edge to the element pad, thereby, the load of the main circuit can be improved, and the problem of different brightness of the lamp strip at the head and tail can be reduced or avoided, and the main circuit is less likely to heat due to the relatively large width of the main circuit at least in part; the non-metal area in the circuit board can be obviously reduced due to the wide and narrow main circuit, that is, the area where only the upper and lower two layers of resin films are bonded together is reduced, the resin film has more positions with metal support, so that the resin film will not have a large shrinkage problem when the circuit board is soldered in SMT, and the problems of wrinkles in the circuit board and influence on the appearance of the lamp strip are solved; in the embodiment, the width of the wide and narrow main circuit is increased at least in part relative to the parallel wires with equal width in the prior art, the load of the main circuit is improved, the thickness of the main circuit does not need to be increased to improve the load, thereby, the problem of too thick at both edges and too thin in the middle of the whole circuit board does not occur, so that the circuit board is less likely to deform under high temperature when the SMT reflow soldering element is performed, and is less likely to form bubbles and large bulges, and the yield of the circuit board is improved.

[0031] In a second aspect, the utility model provides a kind of circuit board, comprising:

[0032] a first insulating layer;

[0033] a main line, the main line being a single-layer main line formed of copper-aluminum composite metal or aluminum, or the main line being a double-layer main line formed of aluminum and copper or aluminum and copper-aluminum composite metal, the main line being multiple, arranged at a board edge position of the circuit board, the line width of at least part of the main line being different;

[0034] a sub-line, the sub-line being copper or copper-aluminum composite metal, the sub-line being located in a middle area of the circuit board;

[0035] a second insulating layer;

[0036] the thickness of part or all of the main line being greater than the thickness of the sub-line; the circuit board comprising a metal area with lines and a non-metal area without lines, the first insulating layer and the second insulating layer being bonded in at least part of the non-metal area, the first insulating layer and the second insulating layer clamping the main line and the sub-line;

[0037] a pad window arranged on the first insulating layer or / and the second insulating layer.

[0038] Optionally, the main line is a long line of >1 meter, and the sub-line is a short line of ≤1 meter.

[0039] Optionally, the main line is a double-layer main line, comprising a first main line formed of aluminum and a second main line formed of copper or copper-aluminum composite metal, the first main line and the second main line being at least partially in position overlap contact.

[0040] Optionally, the second main line is a long line of >1 meter; the first main line is a long line of >1 meter, or the first main line is multiple segments, each segment being >1 meter in length, or at least part of the segments being <1 meter in length.

[0041] Optionally, the line width of at least part of the first main line is different.

[0042] Optionally, for a single pad window, the exposed metal is copper, aluminum, or copper and aluminum; in multiple pad windows, the exposed metal of each pad window is the same or different.

[0043] Optionally, the minimum distance between the main line and the sub-line is a, wherein 0.1mm≤a≤0.8mm.

[0044] Optionally, the first insulating layer is a PET film or a PI film with adhesive, and the second insulating layer is a PET film or a PI film with adhesive; the material of the first insulating layer and the second insulating layer is the same or different.

[0045] The utility model discloses second aspect embodiment has at least following one of beneficial effects: the utility model discloses an embodiment through the main line is set to copper aluminium composite metal or the single layer main line of aluminium formation, or the main line is the double layer main line of aluminium and copper, or aluminium and copper aluminium composite metal formation, the main line is more, set in the board edge position of line board, the main line is the long line of >1 meter, and the line width of the main line at least partial position is different;The auxiliary line is copper or copper aluminium composite metal, and the auxiliary line is located in the middle area of line board, and the auxiliary line is the short line of ≤1 meter;The thickness of part or all main line is greater than the thickness of auxiliary line;The line board includes the metal area with line and the nonmetal area without line, and in at least partial area of nonmetal area, the first insulating layer is bonded with the second insulating layer, and the first insulating layer and the second insulating layer clamp the main line and the auxiliary line;Discard the setting mode of the main line being set to the parallel wire of equal width in prior art, in this embodiment, the main line at least partial position width is inconsistent, so that the main line can be set to the width of not being uniform, and the width of the main line is no longer completely limited by the distance space of line board board edge to component pad, thereby, the load of main line can be improved, and the problem that the luminance of lamp strip head and tail is not uniform can be reduced or avoided, and since the main line at least partial position width is larger, the main line is not easy to heat;Since the main line of not being uniform, the nonmetal area in line board can be obviously reduced, that is, the area that only two layers of resin films are bonded together is reduced, the resin film has more positions with metal support, so that when SMT soldering is carried out on line board, the resin film will not have the problem of large shrinkage, and the problems of line board wrinkling and affecting lamp strip appearance are solved;In this embodiment, the main line of not being uniform relative to the parallel wire in prior art, at least partial position increases the width of main line, improves the load of main line, so that the main line does not have to increase the thickness to mention the load, thereby, the problem that the both sides of whole line board are too thick and the middle is too thin does not appear, so that when SMT reflow soldering components, line board is not easy to deform under high temperature, and is not easy to form bubbles and large bulges, and the yield of line board is improved.

[0046] Thirdly, the utility model discloses an embodiment provides a kind of LED lamp strip, including the line board of any one embodiment described in above-mentioned second aspect, the LED lamp pearl is welded on the line board. BRIEF DESCRIPTION OF DRAWINGS

[0047] Figure 1.1 It is the line board plane schematic diagram (bit convenient to show line, hides front film) of prior art with equal-width parallel wire main line;

[0048] Figure 1.2 It is Figure 1.1 It is the section structure schematic diagram (after section, rotate 90 ° and enlarge in clockwise direction) of A-A position;

[0049] Figure 1.3 It isFigure 1.2 schematic diagram of the structure bubble after reflow soldering;

[0050] Figure 2.1 is a plane structure schematic diagram of the main circuit on the first insulation film (the first insulation film has made the pad window, and some pad windows are shielded by the main circuit) in the embodiment of the utility model;

[0051] Figure 2.2 is a plane structure schematic diagram of the auxiliary circuit on the second insulation film in the embodiment of the utility model;

[0052] Figure 2.3 is Figure 2.1 after being turned down by 180 degrees and being attached to Figure 2.2 ;

[0053] Figure 2.4 is Figure 2.3 a plane structure schematic diagram after hiding the first insulation film;

[0054] Figure 2.5 is Figure 2.4 a plane structure schematic diagram of the first insulation film hidden in

[0055] Figure 2.6 is Figure 2.3 a cross-sectional structure schematic diagram of B-B in

[0056] Figure 2.7 is Figure 2.6 an exploded schematic diagram;

[0057] Figure 3.1 is a plane structure schematic diagram of the first main circuit on the first insulation film in another embodiment of the utility model (the first insulation film has made the pad window, wherein, some pad windows penetrate the first insulation film at a non-first main circuit position, some pad windows penetrate the first insulation film and the first main circuit at the first main circuit position, and some pad windows only penetrate the first main circuit at the first main circuit position (the pad windows are shielded by the first main circuit));

[0058] Figure 3.2 is a plane structure schematic diagram of the second main circuit and the auxiliary circuit on the second insulation film in another embodiment of the utility model;

[0059] Figure 3.3 is Figure 3.1 a plane structure schematic diagram after being turned down by 180 degrees and being attached to Figure 3.2 ;

[0060] Figure 3.4 is Figure 3.3 a plane structure schematic diagram after hiding the first insulation film;

[0061] Figure 3.5 is Figure 3.4 a schematic diagram of a planar structure of the first insulating film;

[0062] Figure 3.6 is Figure 3.3 a schematic diagram of a cross-sectional structure of C-C (enlarged after being cut and rotated counterclockwise by 90°);

[0063] Figure 3.7 is Figure 3.6 a schematic diagram of an exploded view;

[0064] BRIEF DESCRIPTION OF DRAWINGS

[0065] 1 - first insulating film, 2 - main line, 21 - first main line, 22 - second main line, 3 - second insulating film, 4 - auxiliary line, 5 - pad window, 51 - scissor pad, 52 - lamp bead pad, 53 ~ test pad, 10 - glue. DETAILED DESCRIPTION

[0066] To make the purpose, technical scheme and advantages of the present application more clear, the embodiments of the present application will be described in detail below with reference to the drawings. It should be noted that the embodiments described below and the features in the embodiments can be combined with each other arbitrarily without conflict.

[0067] Many different implementations or examples are provided below to implement the structure of the present application.

[0068] The first aspect of the embodiment of the present application provides a manufacturing method of a circuit board, comprising: providing a first insulating film 1, the first insulating film 1 is a film with glue 10, the first insulating film 1 selects a PET film with glue, and a PI film with glue can also be selected; bonding a first metal foil on the first insulating film 1 with glue, the first metal foil is a copper-aluminum composite foil, using the copper-aluminum composite foil can meet the requirements of soldering tin of the circuit board, at the same time, aluminum can reduce the cost, the first metal foil can also select an aluminum foil, and in the subsequent use process of the circuit board, a special solder paste of weldable aluminum can be selected; using a die cutting method to die cut the first metal foil, tearing off the unnecessary metal, and the metal left on the first insulating film 1 forms a first line group, the first line group is multiple, and there are at least two main lines 2 in the first line group, in the embodiment, the first line group is two continuous and extended main lines 2. The width of each main line 2 is inconsistent at least in part, that is, for a single main line 2, the width can be different at different positions, and the width is not uniform at any position, therefore, the two main lines will not form parallel wires with equal width, see Figure 2.1As shown, the main circuit 2 has 3 repeating units from left to right, a single main circuit in each unit, the width of which is consistent at some positions and different at some positions; in actual production, the main circuit 2 can have dozens of repeating units from left to right to meet the length requirement of the circuit. A second insulating film 3 is provided, which is a film with adhesive 10, and the second insulating film 3 can be a film with adhesive PET or a film with adhesive PI. The second insulating film 3 can be the same material as the first insulating film 1, such as both using a film with adhesive PI, or different from the first insulating film 1, such as the first insulating film 1 using a film with adhesive PET and the second insulating film 3 using a film with adhesive PI. A second metal foil is bonded on the second insulating film 3. When the first metal foil is a copper-aluminum composite foil, the second metal foil is a copper foil. When the first metal foil is an aluminum foil, the second metal foil can be a copper foil or a copper-aluminum composite foil. After the second metal foil is die-cut, the unnecessary metal is torn off, and the metal left on the second insulating film 3 forms a second circuit group. The second circuit group has multiple secondary circuits 4, which are mainly used for welding elements such as LED lamp beads and resistors. The first insulating film 1 with the first circuit group and the second insulating film 3 with the second circuit group are laminated together. During lamination, a mold is used for alignment lamination, and a set pressure and temperature are applied during lamination to bond the first insulating film 1 and the second insulating film 3 through the adhesive 10. Thus, the first insulating film 1 and the second insulating film 3 sandwich the first circuit group and the second circuit group in the middle to form a circuit board. In the above manufacturing process, the first insulating film 1 and / or the second insulating film 3 also need to be die-cut to form pad windows to expose the metal pads. The manufacturing of the pad window 5 will be described in detail below.

[0069] In some embodiments of the present application, when the first insulating film 1 with the first circuit group and the second insulating film 3 with the second circuit group are laminated together, there are two schemes. Scheme one: the first circuit group and the second circuit group do not overlap, as shown in Figure 2.4 Scheme two: the first circuit group and the second circuit group can partially overlap. For example, when the second metal foil is die-cut, the second metal foil is retained at the set shear position pad 51. The second metal foil overlaps the main circuit at the shear position pad position. At this time, the second metal foil on the shear position pad 51 overlaps the main circuit. The second metal foil at this position forms part of the main circuit. According to the different positions of the pad window, the exposed pad metal of a single pad window 5 can be copper, aluminum, or copper and aluminum. The circuit board has multiple pad windows. The exposed metal in each pad window 5 can be the same, such as copper, or different, such as some pad metals being copper and some pad metals being aluminum. See Figure 2.3As shown, the metal of the scissor pad 51 is copper on the surface of the first metal foil, i.e., the copper-aluminum composite metal. The metal of the LED bead pad 52 is sometimes copper from the second metal foil, and sometimes copper (or aluminum) from the first metal foil. Figure 2.3 Alternatively, a pad window can be opened on the back side (i.e., the second insulating film 3), so that the pad metal exposed in the back pad window is aluminum on the first metal foil. The pad on the back side can be used as a test pad. During testing, the test probe only needs to be pressed on the aluminum in the pad window to conduct electricity.

[0070] See details Figures 2.1-2.7 As shown, in some embodiments of this utility model, during bonding, the first circuit group and the second circuit group do not overlap. The method for fabricating the pad window is as follows: after providing the first insulating film 1, the pad window 5 is fabricated on the first insulating film 1 by die-cutting. That is, before the first metal foil is bonded, the pad window is fabricated first by die-cutting according to the circuit and pad design requirements. Figure 2.1 In the structure shown, after the pad window is fabricated, the first metal foil is bonded to partially cover the pad window, and then the first metal foil is die-cut to form the first circuit group. Figure 2.1 In some embodiments, after providing the second insulating film 3, before bonding the second metal foil, pad windows 5 are formed on the second insulating film 3 by die-cutting. In other embodiments, some pad windows are formed on the first insulating film 1 and some pad windows are formed on the second insulating film 3. That is, the pad windows can be set on the first insulating film 1 or the second insulating film 3 alone, or they can be set on the first insulating film 1 and the second insulating film 3 at the same time. In some embodiments, during bonding, the first circuit group and the second circuit group partially overlap. The method for making the pad windows is as follows: after providing the first insulating film 1, the pad windows are made by die-cutting before bonding the first metal foil, as described above. Alternatively, the first insulating film 1 with the first circuit group can be die-cut to make the pad windows, and the pad windows penetrate the first insulating film. In this case, the exposed pad metal in the pad window is the metal of the second metal foil, or as described above. Figure 2.1 , Figure 2.3As shown, the metal exposed in part of the pad is the first metal foil metal, and the metal exposed in part of the pad is the second metal foil metal; in other embodiments, the manufacturing method of the pad window is to manufacture the first insulating film with the first circuit group by die cutting, so that part of the pad window penetrates the first insulating film 1, and part of the pad window penetrates the first insulating film 1 and the metal of the first circuit group. This manufacturing method can also make the pad metal exposed in the pad window be the second metal foil metal or part of the second metal foil metal and part of the first metal foil metal; in other embodiments, the manufacturing method of the pad window is to provide the second insulating film 3, and then manufacture the pad window on the second insulating film 3 by die cutting. According to the position of the pad window relative to the first metal foil and the second metal foil, the pad metal exposed in the pad window can be the second metal foil metal or the first metal foil metal. Of course, it can also be that part of the pad window simultaneously exposes two metal foils, such as the pad window being arranged at the overlapping position of the first circuit group and the second circuit group. The pad metal in the pad window is half of the second circuit group metal and half of the first circuit group metal.

[0071] Referring again to Figures 2.1-2.3 , the manufacturing method of the circuit board is as follows: the first insulating film 1 with the main circuit 2 and the pad window 5 shown in Figure 2.1 is turned over by 180°, so that the main circuit 2 faces Figure 2.2 the sub-circuit 4, and then is aligned and attached, that is, the circuit board shown in Figure 2.3 is obtained.

[0072] Referring to Figures 3.1-3.7 , the utility model further provides another manufacturing method of a circuit board, which comprises the following steps: providing a first insulating film 1, which is a film with adhesive 10 and can be a PET film with adhesive or a PI film with adhesive; bonding a first metal foil on the first insulating film 1, the first metal foil being an aluminum foil, which has a lower cost than a copper foil, thereby ensuring the low cost of the circuit board; die cutting the first metal foil to tear off unnecessary metal, and the metal remaining on the first insulating film 1 forms a first circuit group, which comprises a plurality of first main circuits 21, and each first main circuit 21 has a position width that is inconsistent at least in part, as shown in Figure 3.1 , wherein the first circuit group comprises two first main circuits 21; as shown in Figure 3.2 , providing a second insulating film 3, which is a PI film with adhesive or a PET film with adhesive; bonding a second metal foil on the second insulating film 3, the second metal foil being selected from a copper foil or a copper-aluminum composite foil; die cutting the second metal foil to tear off unnecessary metal, and the metal remaining on the second insulating film 3 forms a second circuit group, which comprises a plurality of second main circuits 22 and a plurality of sub-circuits 4, as shown in Figure 3.2In the structure shown, there are two main lines 22 and nine secondary lines 4; see details. Figure 3.3 As shown, the first insulating film 1 with the first circuit group and the second insulating film 3 with the second circuit group are bonded together. Specifically, the first insulating film 1 with the first circuit group and the second insulating film 3 with the second circuit group are bonded together. Figure 3.1 After the structure shown is flipped downwards by 180°, the first main line 21 faces downwards. Figure 3.2 The second main circuit 22 shown is then aligned and bonded together, so that the first insulating film 1 and the second insulating film 3 are bonded (specifically, the adhesive 10 on the two films is bonded). The first insulating film 1 and the second insulating film 3 sandwich the first main circuit 21, the second main circuit 22, and the auxiliary circuit 4 in the middle, and the second main circuit 22 overlaps and contacts the first main circuit 21 to conduct electricity; in this embodiment, it is different from Figures 2.1-2.7 The embodiment shown is as follows: Figures 2.1-2.7 In the process, the first metal foil is die-cut to form the main circuit 2, and the second metal foil is die-cut to form the secondary circuit 4. Figures 3.1-3.7 In the illustrated embodiment, the main circuit 2 is formed by the first main circuit 21 after die-cutting from the first metal foil and the second main circuit 22 after die-cutting from the second metal foil. Although the first metal foil is aluminum foil, which has poor solderability (for ordinary solder paste), the second metal foil is copper foil or copper-aluminum composite foil. The copper on it has good solderability. The second main circuit 22 obtained after die-cutting from the second metal foil can achieve conductivity as long as it contacts the aluminum first main circuit 21. The second main circuit 22 is exposed in the pad window to meet the solderability requirements. Therefore, in this embodiment, the main circuit 2 is cleverly divided into the first main circuit 21 made of aluminum and the second main circuit 22 made of copper (or copper-aluminum composite metal) to form a double-layer main circuit. This reduces the use of copper (compared to the main circuit being entirely made of copper), reduces the copper material used in the circuit board, and achieves the purpose of reducing the cost of the circuit board. The fact that each first main line 21 has a different line width at least in some places replaces the parallel conductors of equal width in the prior art, which improves the current load capacity of the main line. Under the same load, it helps to reduce the thickness of the main line and avoid problems such as heat generation and large bulges. The fact that each first main line 21 has a different line width at least in some places also reduces the non-metallic area on the circuit board.

[0073] It can be understood that, in the process of manufacturing the circuit board, the die cutting method is also needed to form the pad window 5 for the first insulating film 1 or / and the second insulating film 3. In some embodiments of the present application, the manufacturing method of the pad window is as follows: the first insulating film 1 with the first line group is manufactured into the pad window 5 by using the die cutting method, the pad window 5 penetrates through the first insulating film 1, so that after being attached, the metal of the second main line 22 originally covered by the first insulating film 1 is exposed to form a pad, the position of the pad window penetrating through the first insulating film 1 can also be the position of the first main line 21, so that the aluminum on the first main line 21 is exposed in the pad window, and the pad can be used as a test pad 53, the test pad is used as a temporary pad, and the test requirement can be met by pressing the test needle on the pad; in other embodiments, part of the pad window 5 penetrates through the first insulating film 1, and part of the pad window 5 penetrates through the first insulating film 1 and the metal of the first line group, as shown in FIG. 8; it can be understood that, the second insulating film 3 can also be provided, and then the pad window can be manufactured on the second insulating film 3 by using the die cutting method; according to the manufacturing method and the manufacturing position of the pad window, in some embodiments of the present application, the pad exposed in the pad window 5 is the second metal foil metal; in other embodiments, part of the pad exposed in the pad window 5 is the second metal foil metal, and part of the pad exposed in the pad window is the first metal foil metal, as shown in FIG. 9, and part of the pad exposed in the pad window is the first metal foil, that is, aluminum (test pad 53); in other embodiments, the pad exposed in the pad window includes the first metal foil metal and the second metal foil metal, as shown in FIG. 10. Therefore, for a single pad window 5, the metal exposed is copper or aluminum, or copper and aluminum, and the metal exposed in each pad window is the same or different in a plurality of pad windows. Figure 3.1 Figure 3.3 Figure 3.3

[0074] In some embodiments of the present application, the second main line 22 is two, which is arranged on both sides of the sub-line 4, the second main line 22 extends along the length direction of the circuit board, the length of the second main line is > 1 meter, and the second main line 22 is an uninterrupted long wire with a length of > 1 meter, which is helpful to improve the strength of the circuit board and avoid the circuit board from being scattered; it can be understood that, the length of the second main line is not necessarily > 1 meter, but is a preferred embodiment.

[0075] From the above analysis, it can be seen that, whether it is the embodiment shown in FIG. 7, or the embodiment shown in FIG. 8, or the embodiment shown in FIG. 9, or the embodiment shown in FIG. 10, Figures 2.1-2.7 Figures 3.1-3.7 ​​​​In the embodiment, the width of the main line is not uniform, and the width of the main line is no longer completely limited by the distance space from the board edge to the element pad, thereby the load of the main line can be improved, the problem of uneven brightness of the lamp strip at the head and tail is reduced or avoided, and the main line is less likely to heat up due to the larger width of the main line at least at some positions.

[0076] The utility model discloses a second aspect embodiment provides a kind of circuit board, including first insulating layer, corresponding first insulating film 1;Main line 2, the main line 2 is the single-layer main line of copper-aluminum composite metal or aluminum formation ( Figures 2.1-2.7 Corresponding second aspect embodiment), or the main line 2 is the double-layer main line of aluminum and copper, or aluminum and copper-aluminum composite metal formation (corresponding Figures 3.1-3.7The main line 2 is multiple, is arranged at the board edge position of the circuit board, and the line width of at least part of the main line 2 is different; the auxiliary line 4 is copper or copper-aluminum composite metal, the auxiliary line 4 is located in the middle area of the circuit board, and the auxiliary line is used for welding LED lamp beads, resistors and the like; the second insulating layer corresponds to the second insulating film 3, and the thickness of part or all of the main line 2 is greater than the thickness of the auxiliary line 4; the main line 2 is used as a main line for connecting a power supply and is used for supplying power to a plurality of LED lamp beads on the circuit board, so that the main line 2 is made thicker than the auxiliary line 4 to meet the current load requirement and avoid obvious brightness change of the lamp strip at the head and tail, and the auxiliary line 4 is used for supplying power to the LED lamp beads or / and resistors welded on the auxiliary line 4, the LED lamp beads on each auxiliary line are few, and the current load requirement is low, so that the auxiliary line can be made thin, metal materials are saved, and the cost is reduced; the circuit board comprises a metal area with a line and a non-metal area without a line, the first insulating layer (the first insulating film 1) and the second insulating layer (the second insulating film 3) are bonded in at least part of the non-metal area, and the first insulating layer and the second insulating layer clamp the main line 2 and the auxiliary line 4; it can be understood that the first insulating layer and the second insulating layer are bonded through the glue 10 thereon; and the solder pad window 5 is further included.

[0077] In some embodiments of the utility model, the main line 2 is arranged as a long line of >1 meter, and the auxiliary line 4 is arranged as a short line of ≤1 meter.

[0078] Specifically refer to Figures 3.1-3.7As shown in some embodiments of the utility model, the main line is double-layer main line, including first main line 21 formed by aluminum, and second main line 22 formed by copper or copper-aluminum composite metal, first main line 21 and second main line 22 at least partially overlap and contact to conduct, to solve the problem of poor soldering of aluminum and the need for special solder paste for solderable aluminum, and the place where electronic components need to be welded, the pad window can be opened at the position where first main line 21 and second main line 22 do not overlap, exposing second main line 22 and auxiliary line 4 made of copper or copper-aluminum composite metal, using copper to solder, and the aluminum of first main line 21 can be powered by second main line 22 as auxiliary line due to the overlapping contact and conduction with second main line 22, and first main line 21 is made of aluminum, which greatly reduces the copper consumption of the circuit board and reduces the manufacturing cost. In some embodiments of the utility model, the second main line 22 is a long line of >1 meter, which improves the strength of the circuit board and avoids collapse; and the length of the first main line 21 is not limited, specifically, the first main line is a long line of >1 meter, or the first main line is composed of multiple segments, each segment is >1 meter long, or at least part of the segments is <1 meter long, that is, the first main line 21 can be a continuous long line of >1 meter, or can be composed of multiple short lines of <1 meter.

[0079] As Figures 3.1-3.4 shown, in some embodiments of the utility model, the first main line 21 is the main current load line, and the line width of at least part of the position is different, to reduce the thickness of the first main line 21, reduce the area of the metal-free area on the circuit board, and reduce or eliminate the problem of large bulges, and the second main line is used for electrical connection between the first main line 21 and the auxiliary line 4, and the line width can be the same, or can be designed to be different according to circuit design.

[0080] In some embodiments of the utility model, as described in the method embodiment, for a single pad window 5, the exposed metal is copper, aluminum, or copper and aluminum; and in multiple pad windows 5, the metal exposed by each pad window 5 is the same or different.

[0081] Since the width of at least part of the position of the main line 2 is different, in some embodiments of the utility model, the minimum distance between the main line 2 and the auxiliary line 4 of the circuit board can be designed to be a, where 0.1mm≤a≤0.8mm, to reduce the area of the metal-free area on the circuit board.

[0082] The third aspect of the utility model provides a LED lamp strip, which comprises the circuit board of any one of the second aspect of the utility model, and the LED lamp bead is welded on the circuit board.

[0083] The utility model embodiment makes the detailed explanation in combination with the drawing, but the utility model is not limited to the above -mentioned embodiment, still can make various changes in the knowledge range that the person skilled in the art has possesses without departing from the utility model's tenet under the precondition that the knowledge range that the person skilled in the art has possesses.

Claims

1. A circuit board, characterized in that, include: First insulating layer; The main circuit is a single-layer main circuit formed of copper-aluminum composite metal or aluminum, or a double-layer main circuit formed of aluminum and copper, or aluminum and copper-aluminum composite metal. There are multiple main circuits, which are set at the edge of the circuit board. The width of the main circuit is different at least some of the positions. Sub-circuit, wherein the sub-circuit is made of copper or copper-aluminum composite metal, and the sub-circuit is located in the middle area of ​​the circuit board; Second insulating layer; The thickness of some or all of the main circuits is greater than the thickness of the secondary circuits; the circuit board includes a metallic region with circuits and a non-metallic region without circuits, and in at least a portion of the non-metallic region, the first insulating layer and the second insulating layer are bonded together, and the first insulating layer and the second insulating layer clamp the main circuits and the secondary circuits. The pad window is located on the first insulating layer and / or the second insulating layer.

2. A circuit board according to claim 1, characterized in that: The main line is a long line greater than 1 meter, and the secondary line is a short line less than or equal to 1 meter.

3. A circuit board according to claim 1, characterized in that: The main circuit is a double-layer main circuit, including a first main circuit formed of aluminum and a second main circuit formed of copper or copper-aluminum composite metal, wherein the first main circuit and the second main circuit overlap and are in contact at least partially.

4. A circuit board according to claim 3, characterized in that: The second main line is a line longer than 1 meter; the first main line is a line longer than 1 meter, or the first main line is a series of segments, each segment being longer than 1 meter, or at least some segments being shorter than 1 meter.

5. A circuit board according to claim 3, characterized in that: The width of the first main line is different at least in some locations.

6. A circuit board according to claim 1, characterized in that: For a single pad window, the exposed metal is copper, aluminum, or both copper and aluminum; for multiple pad windows, the exposed metal may be the same or different.

7. A circuit board according to claim 1, characterized in that: The minimum distance between the main line and the secondary line is a, where 0.1mm≤a≤0.8mm.

8. A circuit board according to claim 1, characterized in that: The first insulating layer is an adhesive PET film or PI film, and the second insulating layer is an adhesive PET film or PI film; the first insulating layer and the second insulating layer may be made of the same or different materials.

9. An LED light strip, characterized in that: The circuit board includes any one of claims 1-8, wherein LED beads are soldered onto the circuit board.

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