WO2019037017A1

WO2019037017A1 - Flexible circuit board for led strip and production process thereof

Info

Publication number: WO2019037017A1
Application number: PCT/CN2017/098791
Authority: WO
Inventors: 殷峥凯; 殷永江
Original assignee: 殷峥凯
Priority date: 2017-08-24
Filing date: 2017-08-24
Publication date: 2019-02-28

Abstract

Provided are a flexible circuit board for an LED strip and a production process thereof. The flexible circuit board for an LED strip comprises a flexible insulating base section (1), bare wires and surface-mount LEDs (4). The flexible insulating base section (1) comprises an adhesive layer. The bare wires are adhered to the flexible insulating base section (1) by means of the adhesive layer. The bare wires include a bare positive wire (2) and a bare negative wire (3). The surface-mount LEDs (4) are connected in parallel and provided at a circuit connecting the bare positive wire (2) and the bare negative wire (3). The production process has fewer production steps, thereby reducing production costs.

Description

Flexible circuit board for LED lamp strip and production process thereof

Technical field

The invention relates to an LED lamp strip circuit board, in particular to a flexible circuit board for an LED strip and a lamp strip production process thereof.

Background technique

With the advantages of LED (Semiconductor Light Emitting Diode) in energy saving and environmental protection, it has been widely used in the field of lighting. As a form of LED lighting application, LED strips have been widely used in various decorative industries by assembling LEDs on strip-shaped printed circuit boards.

The circuits of the existing LED strips are generally printed circuits, and the carrier of the printed circuit has a flexible base tape, such as a flexible base tape made of polyimide or polyester film, and a laminate type hard substrate. The printed circuit technology is complicated, the production machine is required to be high, the capital investment is high in the early stage, and the production cost is high. At the same time, due to the limitation of the production technology of the printed circuit, the production length of the printed circuit board is also limited and cannot be continuously produced. For example, the length of the flexible circuit board of the existing LED strip is generally more than one meter long, and the welding process is required to increase the welding process to connect the flexible printed circuit boards for a period of time, the production process is complicated, the production efficiency is low, and the cost is high. In actual use, after cutting at the printed circuit, the segment is often not used normally, resulting in waste and inconvenient use. Therefore, it is necessary to improve the above deficiencies.

Summary of the invention

In order to overcome the above-mentioned deficiencies of the prior art, the present invention provides a flexible circuit board for LED strips and a lamp strip production process capable of continuous production, simple process, low cost, high production efficiency and convenient use. The present invention is achieved by the following technical solution: a flexible circuit board for an LED lamp strip, comprising a flexible insulating base tape and a bare wire, the flexible insulating base tape comprising an adhesive layer, the bare wire being pasted by the adhesive layer On the flexible insulating base tape, the bare wire includes at least two groups, each group includes at least one bare wire, and the bare wires between the groups are parallel to each other to form an LED series connection. Parallel or series-parallel hybrid circuits.

Preferably, the flexible insulating tape is printed with marking points and/or marking lines for positional alignment of the solder paste and/or patch.

Preferably, at least one set of intermittent bare wires are disposed on the circuit connecting the positive and negative bare wires, and the disconnected portion of the intermittent bare wires is used to solder the patch LED.

Preferably, the bare wires comprise at least three groups, wherein in the three groups adjacent in sequence, the polarities of two adjacent bare wires are not fixed, and the polarities of the other bare wires are fixed for parallel connection. The patch LED forms a marquee circuit.

Preferably, at least one set of the bare wires is used to connect the bare wires connected to the positive electrode of the power source to the bare wires, and at least one set of bare wires for connecting to the negative electrode of the power source is a bare wire, and the bare wires are used for the positive and negative wires. Form an LED parallel circuit.

Preferably, the flexible insulating base tape is an insulating plastic tape or an insulating paper tape.

Preferably, the positive and negative bare wires are respectively soldered to the two poles of the patch LED.

Further, the intermittent bare wire is connected to the positive bare wire or the negative bare wire through a chip resistor or a tab.

Preferably, a chip resistor is further included, and the chip resistor is located on a circuit connecting the bare conductors of the positive and negative electrodes.

Preferably, the material of the bare wire comprises one or more of copper, copper alloy, tin-plated copper and silver-plated copper.

Preferably, one of the bare wires is a bare bare wire or a round bare wire, and one set of the bare wires includes at least one of the bare wires.

Further, the insulating plastic tape comprises one or more of a polyimide tape, a paper tape, a masking tape, a DuPont paper tape, and a kraft paper tape, and a polyester tape. One or several of them.

An LED light strip comprising a plastic sleeve, a patch LED, and a flexible circuit board, wherein the flexible circuit board is a flexible circuit board for the LED light strip of any one of the above, the plastic sleeve covers the flexible circuit board With the outer circumference of the patch LED.

A production process of an LED lamp strip, wherein the flexible circuit board of the LED strip is a flexible circuit board for the LED strip. Includes the following steps:

First, bonding, bonding the flexible insulating base tape and the bare wire through the bonding machine;

Second, dripping solder paste, the solder paste is dropped on the circuit connection of the bare wire through the solder paste machine;

Third, the patch, the patch LED or the patch LED and the chip resistor through the placement machine into the solder paste point corresponding to the circuit connection point;

4. Reflow soldering, which will be equipped with a chip LED or a semi-finished product with a chip LED and a chip resistor placed in a reflow soldering machine for soldering;

5. Forming, the semi-finished product after welding is injection molded or extruded by an injection molding machine or a plastic extrusion machine to obtain the LED light strip.

The invention has the beneficial effects that the flexible insulating base tape and the bare wire are bonded to replace the traditional printed circuit, the production technology is greatly simplified, the capital investment of the pre-production equipment is reduced, the production length is not limited, and the welding can be performed without a section of welding. Continuous production of dozens or even hundreds of meters of long LED strips simplifies the production process, greatly reduces production costs, and improves production efficiency. When cutting, bare wires are easy to connect, and the circuit footprint is low, beautifying the look and feel. When the flexible insulating base tape is a transparent material, the LED light strip has better luminous effect, is safe and reliable, is convenient to use, has a long service life, and can realize mechanization, industrialization, and standardized continuous production.

DRAWINGS

The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

1 is a schematic front view showing the structure of a first embodiment of the present invention;

Figure 2 is a schematic cross-sectional view of Figure 1;

3 is a schematic structural view of a bare conductor according to Embodiment 1 of the present invention;

Figure 4 is a cross-sectional view of Figure 3;

FIG. 5 is a schematic structural diagram of a circuit according to Embodiment 1 of the present invention; FIG.

6 is a cross-sectional view showing a bare wire before punching treatment according to Embodiment 2 of the present invention;

7 is a front view of a bare wire before punching treatment according to Embodiment 2 of the present invention;

8 is a schematic structural view of a bare wire after punching treatment according to Embodiment 2 of the present invention;

9 is a schematic structural diagram of a circuit according to Embodiment 2 of the present invention;

10 is a schematic structural diagram of a circuit according to Embodiment 3 of the present invention;

11 is a schematic structural view of an intermittent bare wire according to Embodiment 3 of the present invention;

Figure 12 is a cross-sectional structural view showing a third embodiment of the present invention;

Figure 13 is a front elevational view showing the base tape after printing in accordance with a third embodiment of the present invention;

14 is a schematic structural diagram of a circuit according to Embodiment 4 of the present invention;

Figure 15 is a front elevational view showing a flexible circuit board prior to punching processing according to Embodiment 5 of the present invention;

Figure 16 is a front elevational view of the flexible circuit board of Figure 15 after being treated with a punched solder paste;

17 is a schematic structural diagram of a circuit of a 5050 SMD LED according to Embodiment 5 of the present invention;

Figure 18 is a front elevational view of the flexible circuit board of Figure 16 after patch processing;

Figure 19 is a flow chart showing the production process of the LED lamp strip of the present invention.

In the figure, 1-baseband, 2-positive bare conductor, 3-negative bare conductor, 4-patch LED, 5-plastic sleeve, 6-solder paste, 7-intermittent bare conductor, 8-punch, 9- Chip resistor, 10-point mark, 11-mark line, 12-mark line, 13-A set of chip LED, 14-B set of chip LED, 15-C group of chip LED, 16-first set of bare wire , 17-Second group bare wire, 18-third group bare wire, 19-drive controller, 20-microprocessor IC, 21-bonder, 22-bare wire strip positioning machine, 23-bare wire axle , 24 - bare wire axle, 25 - drop solder paste machine, 26 - SMT placement machine, 27 - reflow soldering machine, 28 - extrusion machine, 29 - minute shearing machine, 30 - guide piece.

Detailed ways

The present invention will be further described below in conjunction with the drawings and embodiments:

Example 1

The LED strip of the present embodiment, as shown in FIG. 1-5, includes a patch LED 4 and a plastic sleeve 5, and further includes a flexible insulating base tape 1 and a bare conductor. The flexible insulating base tape 1 includes a bonding layer, and the bare conductor passes through the bonding layer. Pasted on the flexible insulating base tape, the bare wire includes the positive bare wire 2 and the negative bare wire 3, the positive bare wire 2 and the negative bare wire 3 are parallel, the positive and negative

bare wires

2, 3 are connected with the power source, and the patch LED 4 is located in the connection, On the circuit of the negative

bare wires

2, 3, the plastic sleeve 5 covers the outer periphery of the flexible insulating base tape 1, the bare wire, and the patch LED 4.

The positive electrode bare wire 2 and the negative electrode bare wire 3 of the present embodiment are respectively a group, and the patch LEDs 4 are arranged in parallel on the circuit connecting the positive bare wire 2 and the negative bare wire 3, specifically, the positive electrode of the patch LED4 of this embodiment The negative electrode is soldered to the positive and negative

bare wires

2 and 3 through the solder paste 6 respectively, that is, the chip LED 4 is disposed on the circuit connecting the positive bare wire 2 and the negative bare wire 3, when the positive and negative bare wires 2 are 3, the applicable power supply is turned on, and the patch LED 4 can be ignited. The LED light strip of the embodiment can be applied to the power supply in the prior art, and the chip resistor can be set on the circuit connecting the positive and negative

bare wires

2 and 3. In practice, the chip resistors can be soldered to the positive and negative

bare wires

2, 3 in series with the patch LEDs 4.

The bare wire of the embodiment, that is, the outer surface of the wire is not covered with an insulating material, and the material of the bare wire is preferably one or more of copper, copper alloy, tinned copper and silver plated copper to facilitate the solder paste 6 Welding. The bare wire is preferably a bare bare wire, that is, the shape of the cross section thereof may preferably be a flat ellipse, a square or a rectangle, a trapezoid or the like to facilitate the adhesion and fixation of the bare wire to the flexible insulating tape 1 and the solder paste 6.

The flexible insulating base tape 1 of the present embodiment, that is, the base tape 1 is flexible and bendable, and the material thereof is an insulating material, preferably an insulating plastic tape or an insulating paper tape. The insulating plastic tape preferably includes one or more of a polyimide tape, a polyester tape, and a fiber tape. The insulating paper tape preferably includes one or more of paper tape, masking tape, DuPont paper tape, and kraft paper tape.

The plastic sleeve 5 of the embodiment can function to protect the internal components.

Example 2

The LED strip of the present embodiment is transformed as follows on the basis of the embodiment 1. As shown in FIG. 6-9, in the flexible circuit board of the LED strip, the cross-section of the bare conductor has a circular shape, that is, a bare circle. Before the wire is punched, the bare wire includes a set of positive bare wires 2 and a set of negative bare wires 3, each of which includes two round bare wires, and the positive bare wires 2 are partially formed by laser cutting or mechanical punching. The intermittent bare wire 7, the intermittent bare wire is located on the circuit connecting the positive and negative

bare wires

2, 3, and the disconnected portion of the intermittent bare wire 7 is connected through the soldering chip LED4 to form a patch LED series circuit, One end of the series connected circuit is connected to the positive electrode of the power source, and the other end of the circuit is connected to the bare lead wire 3 through the chip resistor 9.

Example 3

The LED strip of the embodiment is modified as follows on the basis of the embodiment 1. As shown in FIG. 10-12, the bare conductor further includes a discontinuous bare conductor 7, and the intermittent bare conductor 7 is located at the bare conductor of the positive and negative poles 2. 3, preferably located in the middle of the positive and negative

bare wires

2, 3, and parallel with the positive and negative

bare wires

2, 3, the intermittent bare wire 7 is located on the circuit connecting the positive and negative

bare wires

2, 3, the patch The LED 4 is located at the break of the intermittent bare wire, that is, the punch 8. The intermittent bare wire 7 may be bonded to the flexible insulating tape 1 by a continuous bare wire, and the continuous bare wire may be formed into a discontinuous bare wire 7 by laser cutting or mechanical punching.

The intermittent bare wire 7 of the embodiment includes a plurality of bare wire segments, and the bare wire segment is located on a circuit connecting the positive and negative bare wires to function as a circuit connection, and the patch LED 4 is located between the bare wire segments. At the same time, the positive and negative electrodes of the patch LED4 are respectively soldered to the bare wire segments through the solder paste 6.

In this embodiment, three patch LEDs 4 are arranged in series on the circuit connecting the positive and negative

bare wires

2, 3, and one chip resistor 9 passes through the solder paste to connect the bare wire segment of the positive terminal of the LED 4 and the bare wire of the positive electrode through the solder paste. 2 connection, the other chip resistor 9 connects the bare wire segment of the negative terminal of the series chip LED4 with the negative bare wire 3 through the solder paste, and the positive and negative

bare wires

2, 3 are connected to the applicable power source to illuminate the patch. The LED 4 forms a circuit unit. In this embodiment, a plurality of circuit units are arranged in parallel on the positive and negative

bare wires

2 and 3 to realize LED string and parallel combination circuits. The chip resistor 9 of this embodiment can also be converted into a guide tab, which facilitates placement soldering.

The flexible insulating base tape of the LED lamp strip of this embodiment is preferably printed with marking points and/or marking lines for the solder paste. And/or position calibration of the patch. As shown in FIG. 14, the base tape 1 is printed with a marking point 10, a bare wire position marking line 11 and a patch LED marking line 12 to facilitate positional alignment, which facilitates mechanization, industrialization and standardization of the LED strip.

Example 4

The LED light strip of the embodiment, as shown in FIG. 14, is a marquee type light strip, including a patch LED and a plastic sleeve, and further comprises a flexible insulating base tape and a bare wire, the flexible insulating base tape comprises a bonding layer, and the bare wire passes through the adhesive layer. The bonding layer is pasted on the flexible insulating base tape, and the bare wire comprises a first group of bare wires 16, a second group of bare wires 17 and a third group of bare wires 18, wherein the three groups of bare wires are parallel, and the two electrodes of the chip LED are respectively soldered On any two adjacent bare wires, the patch LED includes a group A patch LED 13, a group B patch LED 14 and a group C patch LED 15, wherein each group of patch LEDs are sequentially arranged at intervals, and the three sets of patch LEDs are formed. A circulating unit, the LED strip includes a plurality of circulating units, and the three sets of bare wires are connected to the power source through the driving controller 19. In use, one circulating unit includes three working states: one, a microprocessor in the driving controller 19. The IC20 converts the first group of bare wires 16 to the positive electrode according to the set time parameter, the second group of bare wires 17 is negative, and the third group of bare wires 18 is disconnected. At this time, only the group A patch LEDs 13 are lit; The processor IC 20 changes the time parameter according to the set time. The bare wire 16 is disconnected, the second bare wire 17 is negative, and the third bare wire 18 is positive. At this time, only the B group LED 14 is lit; third, the microprocessor IC 20 is changed according to the set time parameter. The first set of bare wires 16 are negative electrodes, the second group of bare wires 17 are positive, and the third group of bare wires 18 are disconnected. At this time, only the group C patch LEDs 15 are lit to realize the marquee effect.

Example 5

The LED strip of the present embodiment, as shown in FIG. 15-18, is a colorful color-changing strip, which is transformed on the basis of Embodiment 4, and the bare wire is pasted on the flexible insulating base tape 1 through the adhesive layer, and is bare. The wire comprises 5 groups, each group being parallel to each other, wherein the outermost two groups are the bare bare wires 3, and the other three bare wires respectively correspond to the circuit connection of the 5050 patch LED4 through punching to form the intermittent bare wires. One end of each group of intermittent bare wires is respectively connected to the positive pole of the power source, and the disconnected portion of each group of intermittent bare wires is used for series LEDs, which are the first group of bare wires 16 and the second group of bare wires 17 respectively. And a third set of bare wires 18, the chip resistor 9 is used to connect the first set of bare wires 16 or the third group of bare wires 18 and adjacent The negative electrode is connected to the bare wire, and the guiding piece 30 is used to cross the first group of bare wires 16 or the third group of bare wires 18 to connect the second group of bare wires 17 and any group of negative bare wires 3, and the solder paste 6 drops respectively. The three sets of bare wires are soldered to the circuit connection of the 5050 chip LED 4, the chip resistor 9 and the tab 30.

A 5050 SMD LED 4 includes three LEDs capable of emitting different colors, the three LEDs respectively electrically connecting the first set of bare wires 16, the second set of bare wires 17, and the same punch at the third set of bare wires 18. In the disconnection, the two outer LEDs are respectively connected to the adjacent negative bare wires 3 through a chip resistor 9, and the middle LED is connected to a set of negative bare wires 3 through a guiding piece 30 to form a circuit path unit. The colorful color-changing lamp strip of the embodiment includes a plurality of circuit path units. In use, the connection and disconnection of the first group of bare wires 16, the second group of bare wires 17, and the third group of bare wires 18 are respectively controlled. Open to achieve different colorful color effects.

The conductive contact between the tabs 30 and the bare wires of this embodiment is insulated. For example, the conductive strips 30 may be wires or chip resistors wrapped or coated with an insulating material, and the lower portion may also be pre-dropped with an insulating glue. To enhance positioning and insulation.

When the production process of the LED lamp strip of the present invention is specifically implemented, as shown in FIG. 19, the following main production steps are mainly included:

1. Bonding, the flexible insulating base tape 1 and the bare wire are processed and bonded by the bonding machine 21; when implemented, the bare wires of each group are respectively processed by the

bare wire tracker

23, 24 through the bare wire striping machine 22; The adhesive tape 1 is bonded to the flexible insulating tape 1 by the roller bonding machine 21, and the adhesion between the base tape 1 and the bare wire can be determined with reference to the convenience of subsequent production. In order to control the accuracy of the solder wire in the flexible insulating base tape bonding position of the bare wire, it is preferable to make the corresponding marking line and punctuation on the flexible insulating base tape 1 in advance, so as to provide reference and basis for accurate positioning of subsequent related components.

Second, drop the solder paste, the solder paste is dropped on the circuit connection of the bare wire through the solder paste machine 25; it is necessary to pay attention to observe whether the solder paste at the connection position of the circuit is full and whether there is a short circuit condition, which can effectively ensure the product quality.

Third, the patch, the patch LED or the patch LED and the chip resistor are pasted into the solder paste point corresponding to the circuit connection point through the mounter 26; this step makes the patch LED or the patch LED and The circuit connection point of the chip resistor is attached to the solder paste corresponding to the circuit connection point of the bare wire. After the chip is completed, the polarity and position of the chip LED can be checked to improve the yield.

4. Reflow soldering, which will be equipped with a chip LED or a semi-finished product with a chip LED and a chip resistor placed in a reflow soldering machine 27 for reflow soldering; here, the reflow temperature needs to be grasped to improve the soldering quality.

5. Forming, the reflowed semi-finished product is injection molded or extruded by an injection molding machine or a plastic extrusion machine 28; that is, the LED lamp strip can be obtained by coating the plastic sleeve on the periphery.

Sixth, the slitting and rolling, the formed continuous LED light strip is cut into segments by the slitting and rolling machine 29 and rolled; the length of the slitting is determined according to actual needs, and the winding is facilitated for storage.

7. Packing and warehousing, the finished product after the filming is packaged and put into storage after passing the inspection.

In the production process, the flexible insulating base tape and the bare wire can realize continuous bonding production in an infinite length, so the circuit welding process between the segments after the segment production is no longer needed, and the printed circuit of the LED lamp strip in the prior art can be replaced. It is capable of mechanization, industrialization and standardized continuous production.

It is to be understood that those skilled in the art will be able to make modifications and changes in accordance with the above description, and all such modifications and variations are intended to be included within the scope of the appended claims.

The present invention is exemplarily described with reference to the accompanying drawings, and it is obvious that the implementation of the present invention is not limited by the above-described manner, as long as various improvements or not improved by the method concept and technical solution of the present invention are adopted. The concept and technical solution of the present invention are directly applied to other occasions, and are all within the protection scope of the present invention.

Claims

A flexible circuit board for an LED lamp strip, comprising: a flexible insulating base tape and a bare wire, the flexible insulating base tape comprising an adhesive layer, the bare wire being adhered to the flexible insulating base tape by the adhesive layer The bare wire includes at least two groups, each group including at least one bare wire, and the bare wires between the groups are parallel to each other to form an LED series, parallel or series-parallel hybrid circuit.
The flexible circuit board for an LED lamp strip according to claim 1, wherein the flexible insulating base tape is printed with marking points and/or marking lines for position calibration of the solder paste and/or the patch. .
The flexible circuit board for LED strips according to claim 1, further comprising at least one set of intermittent bare wires, said intermittent bare wires being located on a circuit connecting said bare and negative bare wires, The disconnection of the intermittent bare wire is used to solder the patch LED.
The flexible circuit board for LED strips according to claim 1, wherein the bare wires comprise at least three groups, and in three of the adjacent groups, the polarity of two adjacent bare wires is not fixed. The other set of bare wires are fixed in polarity for use in parallel patch LEDs to form a marquee circuit.
The flexible circuit board for LED strips according to claim 1, wherein at least one of the bare wires is used for a bare wire connected to a positive electrode of the power source, and at least one of the wires is connected to a negative electrode of the power source. The bare wire is a negative bare wire, and the positive and negative bare wires are used to form an LED parallel circuit.
The flexible circuit board for an LED lamp strip according to claim 1, wherein the flexible insulating base tape is an insulating plastic tape or an insulating paper tape.
The flexible circuit board for LED strips according to claim 1, wherein the positive and negative bare wires are respectively soldered to the two poles of the patch LED.
The flexible circuit board for an LED lamp strip according to claim 3, wherein the intermittent bare wire is connected to the positive bare wire or the negative bare wire through a chip resistor or a tab.
A flexible circuit board for an LED lamp strip according to claim 1, further comprising a chip resistor, said chip resistor being located on a circuit connecting said bare and negative conductors.
The flexible circuit board for an LED lamp strip according to claim 1, wherein the material of the bare wire comprises one or more of copper, copper alloy, tin-plated copper, and silver-plated copper.
The flexible circuit board for an LED lamp strip according to claim 1, wherein one of the bare wires is a bare bare wire or a round bare wire, and one of the bare wires includes at least one of the bare wires.
The flexible circuit board for LED strips according to claim 6, wherein the insulating plastic tape comprises one or more of a polyimide tape, a polyester tape and a fiber tape, and the insulating paper tape Includes one or more of paper tape, masking tape, DuPont paper tape, and kraft paper tape.
An LED lamp strip comprising a plastic sleeve, a patch LED, and a flexible circuit board, wherein the flexible circuit board is the flexible circuit board for LED strips according to any one of claims 1 to 12, the plastic A sleeve encloses the flexible circuit board and an outer circumference of the patch LED.
A manufacturing process of an LED strip, characterized in that the flexible circuit board of the LED strip is the flexible circuit board for LED strips according to claim 1, comprising the following steps:

First, bonding, bonding the flexible insulating base tape and the bare wire through the bonding machine;

Second, dripping solder paste, the solder paste is dropped on the circuit connection of the bare wire through the solder paste machine;

Third, the patch, the patch LED or the patch LED and the chip resistor through the placement machine into the solder paste point corresponding to the circuit connection point;

4. Reflow soldering, which will be equipped with a chip LED or a semi-finished product with a chip LED and a chip resistor placed in a reflow soldering machine for soldering;

5. Forming, the semi-finished product after welding is injection molded or extruded by an injection molding machine or a plastic extrusion machine to obtain the LED light strip.