A method for manufacturing a circuit board external bridge stacking structure

Abstract

The present invention discloses a method for manufacturing an external bridge stacking structure of a circuit board, obtaining a double-sided circuit PCB device surface, and determining a first pad position and a second pad position on the PCB device surface; obtaining an FPC, the FPC includes a substrate layer and a copper foil layer, the copper foil layer is attached to the substrate layer, and vias are provided at both ends of the FPC, and the vias penetrate the substrate layer and the copper foil layer; using steel screen printing to place solder paste on the first pad position and the second pad position; mounting the first pad position and the second pad position on both ends of the FPC by SMT patch method; using reflow soldering method, the solder paste is dialyzed from the via hole and welded with the via hole, so that the two ends of the FPC are welded on the first pad position and the second pad position. The present invention improves the product design method, reduces the number of product layers, and saves costs; achieves good circuit logic through the principle of external bridge; the type of external FPC is adopted for overlap, and the reliability of fixed bridge is improved by SMT welding method.

Description

Technical Field

[0001] The invention relates to the technical field of soft and hard boards, and in particular to a method for manufacturing an external bridge stacking structure of a circuit board. Background Art

[0002] With the development of technology, the requirements for circuit boards are getting higher and higher. At present, OLED circuit boards are all 4-6 layers of soft and hard boards. The existing multi-layer board lamination method uses hot pressing technology, which has some problems: small pads, high pressure, and easy to cause short circuits. TP and display functions share the same circuit board. Because the product network logic reaches as many as 560 groups, the structure can only be achieved with more than 3 layers. Summary of the invention

[0003] In order to overcome the defects in the prior art, the present invention provides a method for manufacturing an external bridging stacking structure of a circuit board, which achieves good circuit logic through the principle of external bridging; the bridging adopts the type of external FPC, and the reliability of fixed bridging is improved through SMT welding.

[0004] The present invention discloses a method for manufacturing an external bridge stacking structure of a circuit board, and the specific steps include:

[0005] Acquire a double-sided circuit PCB component surface, and determine a first pad position and a second pad position on the PCB component surface;

[0006] Obtain an FPC, wherein the FPC comprises a substrate layer and a copper foil layer, wherein the copper foil layer is attached to the substrate layer, and via holes are provided at both ends of the FPC, wherein the via holes penetrate the substrate layer and the copper foil layer;

[0007] Placing solder paste on the first pad position and the second pad position using a stencil printing method;

[0008] Mounting the two ends of the FPC on the first pad and the second pad by SMT mounting method;

[0009] The solder paste is made to infiltrate from the via hole and be welded to the via hole by reflow soldering, so that the two ends of the FPC are welded to the first soldering pad and the second soldering pad.

[0010] Furthermore, in the above-mentioned method for manufacturing the circuit board external bridge stacking structure, the FPC is arranged on the PCB component surface, and the size of the FPC is 10% to 45% of the size of the PCB component surface.

[0011] Furthermore, in the above-mentioned method for manufacturing the circuit board external bridge stacking structure, the FPC and the test pad on the PCB device surface are staggered.

[0012] Furthermore, in the above-mentioned method for manufacturing an external bridge stacking structure of a circuit board, the FPC is a single-sided circuit, and the FPC includes 25 groups of network logic.

[0013] Furthermore, in the above-mentioned method for manufacturing an external bridge stack structure of a circuit board, a plurality of pads are provided on the first pad position and the second pad position, and the pad size is 0.35 mm.

[0014] Furthermore, in the above-mentioned method for manufacturing the external bridge stacking structure of the circuit board, the line spacing between the pads is 0.15mm.

[0015] Furthermore, in the above-mentioned method for manufacturing an external bridge stacking structure of a circuit board, the size of the via hole is 0.1 mm.

[0016] Furthermore, in the above-mentioned method for manufacturing an external bridge stack structure of a circuit board, the FPC includes two layers of copper foil, the two layers of copper foil are respectively adhered to two sides of the substrate, and a via hole passing through the substrate layer is connected between the two layers of copper foil.

[0017] Furthermore, in the above-mentioned method for making an external bridge structure of a circuit board, the step of "adopting a reflow soldering method to allow the solder paste to seep from the via hole and weld to the via hole, thereby allowing the two ends of the FPC to be welded to the first pad position and the second pad position" the reflow soldering includes a preheating stage, a heat preservation stage, a reflow stage and a cooling stage, the peak temperature of the reflow stage is 230-235°C; the reflow soldering time is 30-45s.

[0018] Furthermore, in the above-mentioned method for manufacturing an external bridge structure of a circuit board, the solder paste in the step of "placing solder paste on the first pad position and the second pad position using a steel screen printing method" includes a paste-like mixture formed by mixing solder powder, flux, a surfactant and a thixotropic agent.

[0019] The beneficial effects of the present invention are as follows:

[0020] The circuit board external bridge stacking manufacturing method of the present invention improves product design mode, reduces the number of product layers, and saves costs; achieves good circuit logic through the principle of external bridge; the bridge adopts the type of external FPC, and improves the reliability of fixed bridge through SMT welding.

[0021] In order to make the above and other purposes, features and advantages of the present invention more obvious and easy to understand, preferred embodiments are specifically cited below and described in detail with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0023] Figure 1 It is a flowchart of the steps of the method for manufacturing the circuit board external bridge stacking structure in an embodiment of the present invention;

[0024] Figure 2 is a schematic structural diagram of a circuit board stack in an embodiment of the present invention;

[0025] Figure 3 is a schematic diagram of solder paste flow in an embodiment of the present invention;

[0026] Figure 4 Schematic diagram of the structure of FPC in an embodiment of the present invention.

[0027] The figure numbers of the above figures are: 1-PCB component surface; 2-FPC; 3-first pad position; 4-second pad position; 5-via; 6-solder paste; 20-substrate layer; 21-copper foil layer. DETAILED DESCRIPTION

[0028] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0029] Example

[0030] like Figure 1 As shown, a method for manufacturing an external bridge stacking structure of a circuit board, the specific steps include:

[0031] Obtain a double-sided circuit PCB component surface 1, and determine a first pad position 3 and a second pad position 4 on the PCB component surface 1;

[0032] Obtain FPC2, FPC2 includes a substrate layer 20 and a copper foil layer 21, the copper foil layer 21 is attached to the substrate layer 20, and vias 5 are provided at both ends of FPC2, and the vias 5 penetrate the substrate layer and the copper foil layer;

[0033] Using stencil printing to place solder paste 6 on the first solder pad position 3 and the second solder pad position 4;

[0034] Mounted on both ends of FPC2 on the first pad position 3 and the second pad position 4 by SMT mounting method;

[0035] The reflow soldering method is adopted to make the solder paste seep from the via hole and weld with the via hole, so that the two ends of the FPC are welded on the first pad position and the second pad position.

[0036] By means of the above method, FPC2 is welded on the PCB device surface 1 by SMT welding through an external bridging method, which improves the product design method, reduces the number of product layers, realizes a method for manufacturing a circuit board external bridging stacking structure, saves costs, and achieves good circuit logic through the principle of external bridging; the bridging adopts the type of external FPC, and the reliability of fixed bridging is improved through SMT welding.

[0037] Specifically, Figure 2 As shown, FPC 2 is arranged on PCB component surface 1, and the size of FPC is 10% to 45% of the size of PCB component surface 1. FPC 2 and the test pad on PCB component surface 1 are arranged in a staggered manner.

[0038] FPC2 can be a single-sided line, and FPC2 includes 25 groups of network logic.

[0039] Specifically, a plurality of pads are disposed on the first pad position 3 and the second pad position 4 . The pad size is 0.35 mm, and the line spacing between the pads is 0.15 mm.

[0040] Specifically, the size of the via hole 5 is 0.1 mm.

[0041] The FPC2 includes two copper foil layers, which are respectively attached to two sides of the substrate, and a via hole penetrating through the substrate layer is connected between the two copper foil layers.

[0042] Specifically, in the step of "adopting reflow soldering to make the solder paste seep through the via and weld with the via, so that the two ends of the FPC are welded on the first pad and the second pad", the reflow soldering includes a preheating stage, a heat preservation stage, a reflow stage and a cooling stage. The peak temperature of the reflow stage is 230-235°C; the reflow soldering time is 30-45s.

[0043] In the specific step of "placing solder paste on the first pad and the second pad by using a steel screen printing method", the solder paste includes a paste mixture formed by mixing solder powder, flux, a surfactant and a thixotropic agent.

[0044] SMT reflow soldering allows the solder paste to melt into a molten state due to heat, and the vias guide the solder paste to flow toward the FPC. After cooling, the solder paste and the metal vias are welded together.

[0045] The present invention uses specific embodiments to illustrate the principles and implementation methods of the present invention. The description of the above embodiments is only used to help understand the method of the present invention and its core idea. At the same time, for those skilled in the art, according to the idea of ​​the present invention, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as a limitation on the present invention.

Claims

1. A method for manufacturing a circuit board external bridge stacking structure, characterized in that: include: Obtain a double-sided circuit PCB component surface, and determine a first pad position and a second pad position on the PCB component surface, wherein a plurality of pads are disposed on the first pad position and the second pad position, the pad size is 0.35 mm, and the line spacing between the pads is 0.15 mm; Obtain an FPC, wherein the FPC includes a substrate layer and two copper foil layers, wherein the two copper foil layers are respectively attached to two sides of the substrate layer, and a via hole passing through the substrate layer is connected between the two copper foil layers, wherein the via hole penetrates the substrate layer and the copper foil layer, and the via hole has a size of 0.1 mm. The FPC is a single-sided circuit, and the FPC includes 25 groups of network logic; Placing solder paste on the first pad and the second pad by using a steel screen printing machine, wherein the solder paste comprises a paste mixture formed by mixing solder powder, a soldering flux, a surfactant and a thixotropic agent; The two ends of the FPC are mounted on the first pad and the second pad by SMT patch method, the FPC is arranged on the PCB component surface, the size of the FPC is 10% to 45% of the size of the PCB component surface, and the FPC is staggered with the test pad on the PCB component surface; Reflow soldering is adopted to make the solder paste seep from the via hole and weld with the via hole, so that the two ends of the FPC are welded on the first pad position and the second pad position. The reflow soldering includes a preheating stage, a heat preservation stage, a reflow stage and a cooling stage. The peak temperature of the reflow stage is 230-235°C; the reflow soldering time is 30-45s.

Images