Production process of LED flexible circuit board with infinitely long double-sided tin conduction blind hole

Abstract

The invention provides a production process of an LED flexible circuit board with an infinitely long double-sided tin conduction blind hole, and aims to solve the problems of high cost and low efficiency caused by plasma cleaning and blind hole electroplating in the prior art and solve the problem that the traditional production mode cannot meet the requirement of an infinitely long circuit board. Continuous production is conducted in a roll-to-roll mode, the blind holes are formed through laser drilling, conduction between the top-layer copper foil and the bottom-layer copper foil at the positions of the blind holes is achieved through the SMT technology and the reflow soldering technology, and plasma cleaning and blind hole electroplating are not needed. The process is suitable for producing the LED flexible circuit board with the length range of 1-200m, the cost can be effectively reduced, the production efficiency is improved, and the reliability and the quality of the product are enhanced. The invention relates to the technical field of flexible circuit board production.

Description

Technical Field

[0001] The invention relates to the technical field of flexible circuit board production, and in particular to a production process of an infinitely long double-sided tin-conducting blind-hole LED flexible circuit board. Background Art

[0002] In the manufacturing process of flexible printed circuits (FPCs), especially for application scenarios that require high-density interconnection, such as LED displays or internal components of mobile devices, blind via technology has become one of the key processes for connecting the top and bottom circuits. Existing blind via board manufacturing technology usually uses laser drilling equipment to form a "blind hole" between the top copper foil of the circuit board and the middle polyimide (PI) insulation layer by precisely controlling the laser power, drilling time and drilling depth. In order to ensure that these blind holes can provide reliable conductive connections, plasma cleaning is required to remove residues in the holes, and chemical copper is deposited by blind hole electroplating to achieve conduction between the front copper foil and the bottom copper foil.

[0003] However, the two key steps of plasma cleaning and blind hole electroplating are complex in actual application and are not suitable for LED flexible circuit boards. First, plasma cleaning is to remove the residue in the hole after laser drilling to ensure the effect of subsequent electroplating operations, but this step not only increases the complexity of the process, but also brings additional costs. Secondly, blind hole electroplating is a complex and costly process that requires special electroplating solutions and conditions, consumes a lot of time and energy, and leads to low overall production efficiency.

[0004] Due to technical limitations, most existing blind hole boards can only be produced within a certain length range, generally not exceeding one meter. If a longer circuit board is required, it has to be spliced. This splicing method increases the risk of board breakage and affects the final quality and reliability of the product.

[0005] Therefore, it is imperative to design a production process for infinitely long double-sided tin-conducting blind via LED flexible circuit boards. Summary of the invention

[0006] In view of the defects of the above-mentioned prior art, the present invention provides a production process for infinite length double-sided tin-conducting blind hole LED flexible circuit board, which aims to solve the high cost and low efficiency problems caused by plasma cleaning and blind hole electroplating steps in the traditional process of LED flexible circuit board production process, and the problem that traditional production methods cannot meet the demand for infinite length circuit boards.

[0007] To achieve the above object, the technical solution adopted by the present invention is: a production process of an infinitely long double-sided tin-conducting blind via LED flexible circuit board, wherein the LED flexible circuit board is composed of a top copper foil, a PI adhesive layer and a bottom copper foil from top to bottom, including the following steps:

[0008] Step 1: Expose the top copper foil and the bottom copper foil in a roll-to-roll manner;

[0009] Step 2: etching the exposed top copper foil and bottom copper foil to form a circuit pattern;

[0010] Step 3: Perform AOI inspection on the etched LED flexible circuit board;

[0011] Step 4: In the position where the top copper foil is etched off in advance, a laser is used to penetrate the top copper foil and the PI adhesive layer by identifying several MAKE points of the circuit to form a blind hole;

[0012] Step 5: Print solder paste at the positions of the blind holes by SMT components, and conduct the top copper foil and the bottom copper foil through molten tin by reflow soldering;

[0013] Step 6: Paste a cover film on the upper end of the top copper foil to protect the LED flexible circuit board;

[0014] Step 7: Repeat the operation process of step 1 to step 6 for the next operation position of the infinitely long LED flexible circuit board using a roll-to-roll method.

[0015] Furthermore, in step 4, the laser only passes through the top copper foil and the PI adhesive layer without touching the bottom copper foil.

[0016] Furthermore, in step five, top-layer components are placed on the SMT patch, and the top-layer components are fixed on the blind hole by reflow soldering.

[0017] Furthermore, the production process is suitable for manufacturing the LED flexible circuit board with a length of 1-200 meters.

[0018] Furthermore, in step one, the LED flexible circuit board is continuously and seamlessly spliced ​​and exposed in a roll-to-roll manner.

[0019] The present invention is beneficial in that:

[0020] 1. The steps of plasma cleaning and blind hole electroplating in the traditional process are cancelled, which simplifies the production process, reduces unnecessary processes and material consumption, and effectively reduces production costs. The plasma cleaning and blind hole electroplating processes are very time-consuming. Canceling these processes speeds up the entire process, improves production efficiency, and shortens product delivery cycles.

[0021] 2. Use laser precision drilling combined with SMT patch technology and reflow soldering technology to directly achieve the conduction from the top layer to the bottom layer, avoiding impurities and poor conduction that may be introduced by traditional electroplating, and enhancing the reliability and stability of the product;

[0022] 3. The roll-to-roll production method can theoretically produce flexible circuit boards of any length, which solves the length limitation problem in traditional methods and greatly expands the application range of the product. The production process of the present invention supports the manufacture of LED flexible circuit boards with lengths ranging from 1 meter to 200 meters to meet the needs of different customers, especially in application scenarios that require ultra-long flexible circuit boards. It has significant advantages.

[0023] In order to more clearly illustrate the above features of the present invention and its intended objectives, the present invention is further described below in conjunction with the accompanying drawings and specific embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 It is a schematic diagram of the structure of the LED flexible circuit board of the present invention;

[0025] Figure 2 : It is the schematic flow diagram of the production technology of the present invention.

[0026] Explanation of the figure numbers: 1-top copper foil, 2-PI adhesive layer, 3-bottom copper foil, 4-blind hole, 5-cover film, 6-top components. DETAILED DESCRIPTION

[0027] The present invention will be further described in detail below with reference to the accompanying drawings and by way of examples. The following examples are intended to explain the present invention but the present invention is not limited to the following examples.

[0028] Example

[0029] See also Figure 1 to Figure 2 .

[0030] This embodiment discloses a production process for an infinitely long double-sided tin-conducting blind via LED flexible circuit board, wherein the LED flexible circuit board is composed of a top copper foil 1, a PI adhesive layer 2, and a bottom copper foil 3 from top to bottom, and includes the following steps:

[0031] Step 1: Expose the top copper foil 2 and the bottom copper foil 3 using a roll-to-roll method;

[0032] Step 2: etching the exposed top copper foil 2 and bottom copper foil 3 to form a circuit pattern;

[0033] Step 3: Perform AOI inspection on the etched LED flexible circuit board;

[0034] Step 4: In the position where the top copper foil 2 is etched off in advance, a laser is used to penetrate the top copper foil 1 and the PI adhesive layer 2 by identifying several MAKE points of the circuit to form a blind hole 4;

[0035] Step 5: Print solder paste at the positions of several blind holes 4 by SMT components, and conduct the top copper foil 1 and the bottom copper foil 3 through molten tin by reflow soldering;

[0036] Step 6: Paste a cover film 5 on the upper end of the top copper foil 1 to protect the LED flexible circuit board;

[0037] Step 7: Repeat the operation process of step 1 to step 6 for the next operation position of the infinitely long LED flexible circuit board using a roll-to-roll method.

[0038] In step 4 of this embodiment, the laser only passes through the top copper foil 1 and the PI adhesive layer 2, and does not touch the bottom copper foil 3.

[0039] In step five of this embodiment, a top-layer component 6 is placed on the SMT component, and the top-layer component 6 is fixed on the blind hole 4 by reflow soldering.

[0040] In this embodiment, the production process is suitable for manufacturing the LED flexible circuit board with a length of 1-200 meters, which increases the reliability of the LED flexible circuit board and solves the hidden danger of the board breaking when the user installs the finished product.

[0041] In step 1 of this embodiment, the LED flexible circuit board is continuously and seamlessly spliced ​​and exposed in a roll-to-roll manner.

[0042] The above description is only the optimal solution embodiment of the present invention and is not intended to limit the present invention. Various modifications or substitutions made by those skilled in the art to the present invention without departing from the essence and protection scope of the present invention should also be within the protection scope of the present invention.

Claims

1. A production process for an infinitely long double-sided tin-conducting blind via LED flexible circuit board, wherein the LED flexible circuit board is composed of a top copper foil (1), a PI adhesive layer (2) and a bottom copper foil (3) from top to bottom, characterized in that: The steps include: Step 1: performing circuit exposure on the top copper foil (2) and the bottom copper foil (3) in a roll-to-roll manner; Step 2: etching the exposed top copper foil (2) and bottom copper foil (3) to form a circuit pattern; Step 3: Perform AOI inspection on the etched LED flexible circuit board; Step 4: In the position where the top copper foil (2) is etched away in advance, a laser is used to penetrate the top copper foil (1) and the PI adhesive layer (2) by identifying a number of MAKE points of the circuit to form a blind hole (4); Step 5: printing solder paste at the positions of the blind holes (4) by means of SMT components, and conducting the top copper foil (1) and the bottom copper foil (3) by means of molten tin through reflow soldering; Step 6: Pasting a covering film (5) on the upper end of the top copper foil (1) to protect the LED flexible circuit board; Step 7: Repeat the operation process of step 1 to step 6 for the next operation position of the infinitely long LED flexible circuit board using a roll-to-roll method.

2. The infinite length double-sided tin-conducting blind via LED flexible circuit board production process according to claim 1, characterized in that: In step 4, the laser only passes through the top copper foil (1) and the PI adhesive layer (2) without touching the bottom copper foil (3).

3. The infinite length double-sided tin-conducting blind via LED flexible circuit board production process according to claim 1, characterized in that: In step five, a top-layer component (6) is placed on the SMT patch, and the top-layer component (6) is fixed on the blind hole (4) by reflow soldering.

4. The infinite length double-sided tin-conducting blind via LED flexible circuit board production process according to claim 1, characterized in that: The production process is suitable for manufacturing the LED flexible circuit board with a length of 1-200 meters.

5. The production process of an infinitely long double-sided tin-connected blind via LED flexible circuit board according to claim 1, characterized in that: In step 1, the LED flexible circuit board is continuously and seamlessly spliced ​​and exposed in a roll-to-roll manner.

Images