COB lamp strip structure capable of improving lighting effect

Abstract

The COB lamp strip structure capable of improving the lighting effect comprises an FPC substrate and a plurality of chips, the FPC substrate is provided with a first conductive circuit and a second conductive circuit which are arranged in the length direction of the FPC substrate, and a plurality of sets of light-emitting units are arranged between the first conductive circuit and the second conductive circuit in the length direction. The light-emitting unit comprises a positive electrode circuit and a negative electrode circuit which are used for being connected with the chip, the positive electrode circuit is connected with a first bonding pad, the negative electrode circuit is connected with a second bonding pad, the positive electrode circuit is wired from the top of the first bonding pad, the negative electrode circuit is wired from the bottom of the second bonding pad, the first bonding pad and the second bonding pad form a die bonding area, and the size ratio of the die bonding area to the chip is 1: 1. According to the COB lamp strip structure capable of improving the lighting effect, the die bonding area and the chip are manufactured according to the size proportion of 1: 1, the bonding pad and the electrode of the chip completely coincide, the bare copper area on the periphery of the chip is reduced, and therefore the lighting effect of the lamp strip is improved, and the effective brightness of the lamp strip is improved.

Description

TECHNICAL FIELD

[0001] The utility model relates to the production technical field of lamp strip, specifically a COB lamp strip structure of improving light efficiency. BACKGROUND

[0002] COB (Chip on Board) lamp strip, through the direct die bonding of LED chip on FPC (flexible printed circuit board) substrate and integral encapsulation, realizes high density integration and light and thin design, is widely used in display, illumination and other fields, and currently FPC substrate pad design is too large, bare copper also increases after the windowing of solder resist layer or cover film, that is, there is excess copper foil beyond the coverage range of chip electrode on the edge of pad, and the chip cannot cover the pad surface of substrate, and copper surface light absorption will cause low light efficiency, and the large pad design will also relatively increase the amount of solder paste, that is, the overall production cost of lamp strip is increased. SUMMARY

[0003] The utility model discloses a COB lamp strip structure of improving light efficiency, to solve the technical problem in the background art.

[0004] To achieve the foregoing objects, the utility model provides the following technical scheme:

[0005] A COB lamp strip structure of improving light efficiency, comprising FPC substrate and a plurality of chips, the FPC substrate is equipped with first conductive circuit and second conductive circuit along its length direction, the first conductive circuit and second conductive circuit are parallelly arranged at the upper and lower ends of FPC substrate, there are a plurality of groups of light emitting units between the first conductive circuit and second conductive circuit along the length direction, a plurality of groups of light emitting units are sequentially connected, the light emitting unit includes anode line and cathode line for connecting the chip, at least one first pad is communicated on the anode line, and second pad is communicated on the cathode line, the first pad and second pad are correspondingly arranged at the upper and lower positions, the first pad is above the second pad, the anode line is wired from the top of first pad, and the cathode line is wired from the bottom of second pad, the first pad and second pad form die bonding area, and the size ratio of die bonding area and chip is 1:1.

[0006] The anode line includes first main line and two first branch lines, and the two first branch lines are symmetrically and perpendicularly arranged at the left and right ends of first main line, the first branch line is connected to the top of first pad, the cathode line includes second main line and two second branch lines, and the two second branch lines are symmetrically and perpendicularly arranged at the left and right ends of second main line, and the second branch line is connected to the bottom of second pad.

[0007] The first pad and the second pad are rectangular structures, the width of the first branch line and the second branch line is the same, the width of the first pad is the same as the width of the first branch line, and the width of the second pad is the same as the width of the second branch line.

[0008] The width of the first pad and the second pad is 0.19-0.2mm, and the interval between the first pad and the second pad is 0.1-0.13mm.

[0009] Compared with the prior art, the COB lamp strip structure for improving light efficiency of the application is manufactured according to the size ratio of 1:1 of the die bonding area and the chip, the pad and the chip electrode completely coincide, the solder tin can uniformly cover the entire electrode area during welding, the current path cross section is maximized by complete contact, the light emission of the chip is stable, the size of the pad is relatively small, the amount of solder paste is reduced, the direct material cost is reduced, the line of the light emitting unit is designed from the up and down wire of the chip and the small pad, the copper foil and the pad contact surface is reduced, the windowed bare copper foil area of the solder resist layer or the cover film of the FPC substrate is also reduced, the bare copper area around the chip is reduced, thereby improving the light efficiency of the lamp strip and increasing the effective brightness of the lamp strip. BRIEF DESCRIPTION OF DRAWINGS

[0010] Fig. 1 The structure schematic view of the application;

[0011] Fig. 2 The structure view of the light emitting unit;

[0012] Fig. 3 The structure view of the positive line and the negative line in the light emitting unit. DETAILED DESCRIPTION

[0013] The technical scheme in the embodiments of the application will be described clearly and completely in combination with the drawings in the embodiments of the application.

[0014] Specific embodiment 1: please refer to Figs. 1 to 3The utility model discloses an embodiment of a kind of COB lamp strip structure of improving light efficiency, including FPC substrate 1 and several chips 8, FPC substrate 1 is equipped with first conductive circuit 2 and second conductive circuit 3 being arranged along its length direction, first conductive circuit 2 and second conductive circuit 3 are arranged in the upper and lower ends of FPC substrate 1 with upper and lower interval, there are several groups of light emitting units 5 between first conductive circuit 2 and second conductive circuit 3 along length direction, several groups of light emitting units 5 are sequentially connected by third conductive circuit 4, light emitting unit 5 includes the positive line and negative line for connecting chip 8, at least one first pad 6 is communicated on positive line, second pad 7 is communicated on negative line, first pad 6 and second pad 7 position correspond, first pad 6 is above second pad 7, positive line is routed from the top of first pad 6, negative line is routed from the bottom of second pad 7, first pad 6 and second pad 7 form fixed crystal area, the size ratio of fixed crystal area and chip 8 is 1:1, that is, pad and the electrode of chip 8 are completely coincident, solder tin can evenly cover entire electrode area when welding, pad and chip 8 are accurately matched by 1:1 design size, the contact area of copper foil area on pad and chip 8 100% coincides, there is no copper foil beyond electrode coverage range, that is, bare copper area is completely eliminated, the total amount of bare copper foil absorption to light is reduced, and effective light efficiency is improved.

[0015] The positive line in the application includes a first main line 501 and two first branch lines 501-1, the two first branch lines 501-1 are symmetrically and perpendicularly arranged at the left and right ends of the first main line 501, the first branch line 501-1 is connected to the top of the first pad 6, the negative line includes a second main line 502 and two second branch lines 502-1, the two second branch lines 502-1 are symmetrically and perpendicularly arranged at the left and right ends of the second main line 502, the second branch line 502-1 is connected to the bottom of the second pad 7, and the third conductive circuit 4 is connected to the head and tail of the positive line and the negative line, respectively. The first branch line 501-1 and the second branch line 502-1 are routed from the top and bottom of the corresponding pad, which can eliminate the horizontal wiring space occupation of the circuit, optimize the signal transmission path, and improve the electrical performance stability.

[0016] The first pad 6 and the second pad 7 in the application are both rectangular structures, the widths of the first branch line 501-1 and the second branch line 502-1 are the same, the width W2 of the first pad 6 is the same as the width W1 of the first branch line 501-1, the width of the second pad 7 is the same as the width of the second branch line 502-1, the widths of the first pad 6 and the second pad 7 are both 0.19-0.2 mm, and the spacing D1 between the first pad 6 and the second pad 7 is 0.1-0.13 mm. In the embodiment, the width of the first pad 6 and the second pad 7 is 0.19 mm, and the spacing D1 between the first pad 6 and the second pad 7 is 0.13 mm.

[0017] Compared with the prior art, the COB lamp strip structure for improving light efficiency of the application is manufactured according to the size ratio of 1:1 of the die bonding area and the chip, the pad and the chip electrode are completely overlapped, the solder tin can uniformly cover the whole electrode area during welding, the current path cross section is maximized by complete contact, the light emission of the chip is stabilized, the size of the pad is relatively small, the amount of solder paste is reduced, the direct material cost is reduced, and the line of the light emitting unit is designed from the up and down wire of the chip and the small pad, the contact surface of the copper foil and the pad is reduced, the windowed bare copper foil area of the solder resist layer or the cover film of the FPC substrate is also reduced, the bare copper area around the chip is reduced, thereby improving the light efficiency of the lamp strip and increasing the effective brightness of the lamp strip.

[0018] It is apparent for those skilled in the art that the present application is not limited to the details of the foregoing exemplary embodiments, and thus can be implemented in other particular forms without departing from the spirit or essential characteristics of the present application. Accordingly, no matter from which point of view, the embodiments should be considered as exemplary and non-limiting, and the scope of the present application is defined by the appended claims rather than the foregoing description, and thus all variations falling within the meaning and range of the equivalent elements of the claims are intended to be embraced in the present application. Any reference signs in the claims should not be considered as limiting the claims involved.

[0019] In addition, it should be understood that, although the present specification is described in terms of embodiments, not every embodiment contains only one independent technical solution, and the description of the specification is only for the sake of clarity, and those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can be properly combined to form other embodiments that those skilled in the art can understand.

Claims

1. A COB light strip structure for improving light efficiency, characterized in that: The application relates to a flexible printed circuit (FPC) substrate and a plurality of chips, wherein the FPC substrate is provided with a first conductive line and a second conductive line arranged along the length direction of the FPC substrate, the first conductive line and the second conductive line are arranged in parallel at the upper and lower ends of the FPC substrate, a plurality of groups of light emitting units are arranged along the length direction between the first conductive line and the second conductive line, the groups of light emitting units are sequentially connected, the light emitting unit comprises a positive electrode line and a negative electrode line for connecting the chip, at least one first pad is connected to the positive electrode line, a second pad is connected to the negative electrode line, the first pad and the second pad are arranged in a position corresponding to each other, the first pad is arranged above the second pad, the positive electrode line is arranged from the top of the first pad, the negative electrode line is arranged from the bottom of the second pad, the first pad and the second pad form a die bonding area, and the size ratio of the die bonding area to the chip is 1:

1. 2.The COB lamp strip structure of claim 1, wherein: The positive electrode line comprises a first main line and two first branch lines, the two first branch lines are symmetrically and perpendicularly arranged at the left and right ends of the first main line, the first branch line is connected to the top of the first pad, the negative electrode line comprises a second main line and two second branch lines, the two second branch lines are symmetrically and perpendicularly arranged at the left and right ends of the second main line, and the second branch line is connected to the bottom of the second pad. 3.The COB lamp strip structure of claim 2, wherein: The first pad and the second pad are both rectangular structures, the widths of the first branch line and the second branch line are the same, the width of the first pad is the same as the width of the first branch line, and the width of the second pad is the same as the width of the second branch line. 4.The COB lamp strip structure of claim 3, wherein: The widths of the first pad and the second pad are both 0.19-0.2 mm, and the spacing between the first pad and the second pad is 0.1-0.13 mm.

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