Secondary reflow soldering heat insulation device

Abstract

The invention discloses a secondary reflow soldering heat insulation device which comprises a carrier, a flexible circuit board, a steel sheet, a soft heat insulation material and an upper cover plate. The upper surface of the carrier sinks to form a first sinking area and a second sinking area so as to position the flexible circuit board and give way to a first welding device of the flexible circuit board; the steel sheet can be magnetized, and the steel sheet is windowed in a region corresponding to a second welding pad of the flexible circuit board and a region corresponding to the second welding pad; the soft heat insulation material is matched with the upper cover plate, a window is formed in a corresponding area of a second welding pad of the flexible circuit board, and a closed space is formed above the corresponding area of the second welding pad of the flexible circuit board; a plurality of permanent magnets are embedded in the bottom of the carrier; a plurality of permanent magnets are embedded in the top of the upper cover plate; the secondary reflow soldering nickel sheet heat insulation device is assembled and fixed through attraction of the permanent magnet, the steel sheet, the carrier and the upper cover plate.

Description

Technical Field

[0001] The present invention relates to the technical field of new energy integrated busbar CCS production, and in particular to a secondary reflow soldering heat insulation device. Background Art

[0002] When the FPC circuit board of the new energy integrated busbar CCS is double-sided reflow soldering, the bottom of some components is soldered on the whole surface, which is not suitable for fixing by dispensing glue. Therefore, when the FPC circuit board is reflow soldered for the second time, the pads that have been soldered for the first time may have welding quality problems due to secondary tin melting during the second reflow soldering. The welding quality is difficult to confirm from the appearance, so there is a high safety risk. Summary of the invention

[0003] The present invention aims to provide a secondary reflow soldering heat insulation device to solve the above problems. The technical solution is as follows:

[0004] A secondary reflow soldering heat insulation device comprises a carrier, a flexible circuit board, a steel sheet, a soft heat insulation material and an upper cover plate;

[0005] The upper surface of the carrier is sunken to form a first sunken area and a second sunken area; the first sunken area is used to position the flexible circuit board, and its depth is consistent with the thickness of the flexible circuit board; the second welding pad of the flexible circuit board is placed upward, and the second sunken area is used to make way for the first welding device on the flexible circuit board;

[0006] The steel sheet is magnetizable, and the steel sheet has windows in a corresponding area of ​​the second welding pad and a corresponding area of ​​the second welding pad of the flexible circuit board;

[0007] The soft heat-insulating material cooperates with the upper cover plate to open a window in the area corresponding to the second welding pad of the flexible circuit board, and form a closed space above the area corresponding to the second welding pad of the flexible circuit board;

[0008] A plurality of permanent magnets are embedded in the bottom of the carrier; a plurality of permanent magnets are embedded in the top of the upper cover plate; through the permanent magnets, the steel sheet is attracted to the carrier and the upper cover plate to realize the assembly and fixation of the secondary reflow soldering thermal insulation device.

[0009] Furthermore, the soft thermal insulation material is arranged between the steel sheet and the upper cover plate, and the soft thermal insulation material has a window in an area corresponding to the second welding pad of the flexible circuit board; the upper cover plate has no window in an area corresponding to the second welding pad of the flexible circuit board.

[0010] Furthermore, the soft thermal insulation material is arranged on the upper cover plate, and the soft thermal insulation material has no window in the area corresponding to the second welding pad of the flexible circuit board; the upper cover plate has a window in the area corresponding to the second welding pad of the flexible circuit board.

[0011] Furthermore, the soft heat-insulating material and the upper cover plate are bonded into one body by high-temperature resistant glue.

[0012] Furthermore, the soft heat-insulating material is silica gel with a thickness of 1.5 to 2.5 mm.

[0013] Furthermore, the carrier and the upper cover plate are made of synthetic stone.

[0014] Furthermore, the thickness of the steel sheet is 0.08-0.20 mm.

[0015] Furthermore, the steel sheet has a window at a MARK point on the second welding surface of the flexible circuit board.

[0016] Furthermore, the steel sheet limits the maximum size of a single window by arranging a strip with a width of 2 to 3 mm in the window area.

[0017] Furthermore, the secondary reflow soldering thermal insulation device is also fixed by a positioning column.

[0018] Compared with the prior art, the present invention has the following notable features: the present device blocks direct heat conduction from the components on the flexible circuit board by sinking or opening windows on the bottom carrier, steel sheet and upper cover plate, and utilizes the poor thermal conductivity of air to prevent the secondary tin melting caused by excessive temperature at the first welding position. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 is a stacked view of a secondary reflow soldering thermal insulation device according to a first embodiment of the present invention;

[0020] Figure 2 is a front view of a bottom carrier according to a first embodiment of the present invention;

[0021] Figure 3 is a front view of the FPC of the first embodiment of the present invention;

[0022] Figure 4 is a reverse side view of the FPC of the first embodiment of the present invention;

[0023] Figure 5 is a front view of a steel sheet according to a first embodiment of the present invention;

[0024] Figure 6 is a front view of a soft heat insulating material according to a first embodiment of the present invention;

[0025] Figure 7 is a front view of an upper cover plate of a first embodiment of the present invention;

[0026] Figure 8 is a stacked view of a secondary reflow soldering thermal insulation device according to a second embodiment of the present invention;

[0027] Fig. 9 is a front view of an upper cover plate of a second embodiment of the present invention;

[0028] Fig.10 It is a front view of a soft heat insulating material according to a second embodiment of the present invention. DETAILED DESCRIPTION

[0029] To further illustrate the various embodiments, the present invention provides drawings. These drawings are part of the disclosure of the present invention, which are mainly used to illustrate the embodiments and can be used in conjunction with the relevant descriptions in the specification to explain the operating principles of the embodiments. With reference to these contents, a person of ordinary skill in the art should be able to understand other possible implementations and advantages of the present invention. The components in the figures are not drawn to scale, and similar component symbols are generally used to represent similar components.

[0030] The present invention will now be further described with reference to the accompanying drawings and specific implementation methods.

[0031] Example 1

[0032] like Figures 1 to 7 As shown, the secondary reflow soldering heat insulation device of this embodiment comprises, from bottom to top, a carrier 1, an FPC 2, a steel sheet 3, a silica gel or other soft heat insulation material 4 and an upper cover plate 5. Among them:

[0033] FPC 2 needs two reflow soldering. The first reflow soldering is mainly used to complete the soldering of components such as chip resistors, chip capacitors, chip inductors and chips, and the corresponding pads are the first soldering pads 201. The second reflow soldering is mainly used to complete the soldering of components such as sockets, and the corresponding pads are the second soldering pads 202. The two reflow solderings can be on one side of FPC 2 or on both sides of FPC. A MARK point 203 for positioning is also set on FPC2.

[0034] The carrier 1 is generally made of synthetic stone with a thickness of 3 to 7 mm. The carrier 1 is processed and sunk by precision engraving, drilling and milling to form a first sinking area 101 and a second sinking area 102. The first sinking area 101 sinks according to the product shape of FPC 2. Preferably, the sinking size is 0.5 to 1.0 mm more than the product shape of FPC, and the sinking depth is the thickness of FPC 2, so that its secondary welding pad is flush with the surface of the carrier 1. A magnet 7 is buried at the bottom of the carrier 1. The diameter of the magnet 7 is preferably 5 to 20 mm, and the spacing is preferably 25 to 50 mm evenly distributed. It is used to adsorb the steel sheet 3 and the upper cover plate 5 to make them fit better, prevent the reflow hot air from entering, and also play a fixing role.

[0035] The second sinking area 102 is a avoidance area for the first welding pad 201 of the FPC 2. The avoidance area can be designed as a whole according to a single pad or multiple pads. Preferably, the avoidance area is compensated by 1 to 10 mm on one side according to the size of the pad, and the sinking depth is 2 to 4 mm to prevent the welded device from contacting the carrier 1, mainly using the poor thermal conductivity of air to achieve the purpose of heat insulation.

[0036] The thickness of the steel sheet 3 is preferably 0.08-0.20 mm. The steel sheet 3 is opened with a window at the pad position of the FPC 2 where the device needs to be welded. For the first welding pad 201, the window size is 1-10 mm larger than the size of the first welding pad 201 (multiple pads can also be opened as a whole). If the window is larger, a 2-3 mm wide pressure strip 303 can be added at 1 / 2-1 / 3 to prevent the FPC pad from warping during the second reflow soldering. The pressure strip should avoid the position directly above the first welding pad 201 to prevent direct contact with the first welding pad 201 for heat conduction. For the second welding pad 202, it is set according to the convenience of reflow soldering and is not limited here.

[0037] The soft heat-insulating material 4 is generally made of 1.5-2.5mm thick red silica gel or other soft heat-insulating materials. The soft heat-insulating material 4 has a window in the corresponding area 402 of the second welding pad 202, and the window size is the same as the corresponding area 302 of the steel sheet 3; the window is opened in the corresponding area 401 of the first welding pad, and the window size is 1-10mm larger than the first welding pad (multiple pads can also have windows as a whole).

[0038] The upper cover plate 5 is generally made of synthetic stone with a thickness of 3 to 7 mm. The upper cover plate 5 has a window in the corresponding area 502 of the second welding pad 202, and the size of the window is the same as the corresponding area 302 of the steel sheet 3; the corresponding area of ​​the first welding pad has no window, which serves to isolate the direct blowing of the reflow hot air. A magnet 8 is buried on the top of the upper cover plate 5, and the diameter of the magnet 8 is preferably 5 to 20 mm, and the spacing is preferably 25 to 50 mm evenly distributed.

[0039] The soft heat-insulating material 4 and the upper cover plate 5 can be used separately, or can be bonded together with high-temperature resistant glue for easy operation.

[0040] In this embodiment, positioning holes 103, 303, 403 and 503 are further provided at the four corners of each layer plate, and are fixed by four positioning columns 9 to achieve accurate positioning between each layer plate.

[0041] Welding steps:

[0042] 1. Install the FPC according to the shape of the bottom carrier 1, with the pads to be reflow soldered facing upwards.

[0043] 2. Install the steel sheet 3 on the FPC 2 according to the positioning holes according to the shape of the steel sheet window to ensure that the steel sheet 3 is flat.

[0044] 3. Through mark point recognition, let the solder paste printer add tin to the area to be soldered on the second soldering surface of FPC 2, and then proceed with the patch.

[0045] 4. The soft heat-insulating material 4 is installed and placed on the steel sheet 3 according to the positioning holes manually or by a mechanical arm.

[0046] 5. Place the upper cover plate 5 on the soft heat-insulating material 4 manually or by a mechanical arm according to the positioning hole.

[0047] 6. Place the assembled thermal insulation device on the reflow track for welding.

[0048] The device sinks or opens windows on the device positions of the bottom carrier, steel sheet 3 and soft heat-insulating material 4 on the FPC circuit board to block direct contact and heat conduction between them and the nickel sheet, and utilizes the poor thermal conductivity of air to prevent the temperature at the first welding position from being too high and causing secondary tin melting.

[0049] Embodiment 2:

[0050] like Figure 8 As shown, the secondary reflow soldering heat insulation device of this embodiment comprises, from bottom to top, a carrier 1, an FPC 2, a steel sheet 3, an upper cover plate 5 and a silica gel or other soft heat insulation material 4.

[0051] This embodiment is similar to the embodiment 1, and the processing of the carrier 1, the FPC 2, and the steel sheet 3 is as follows: Figure 2 - Figure 5 The materials of the upper cover plate 5 and the soft heat insulating material 4 are selected as shown in Example 1, and the main difference is the stacking order of the soft heat insulating material 4 and the upper cover plate 5 and the hole processing.

[0052] like Fig. 9 and Fig.10As shown, in this embodiment, the upper cover plate 5 has a window at the corresponding position of the first welding pad 201, and the size of the window is 1 to 10 mm larger than the single side of the pad in the first welding pad 201 (multiple pads can also have windows as a whole); the first welding pad position of the soft heat insulation material 4 has no window, and its function is to isolate the direct blowing of the reflow hot air. Similarly, the soft heat insulation material 4 and the upper cover plate 5 can be used separately, or they can be bonded into one with high temperature resistant glue for easy operation.

[0053] The welding steps are:

[0054] 1. Install the FPC according to the shape of the bottom carrier, with the pads to be reflow soldered facing upwards.

[0055] 2. Install the steel sheet 3 on the FPC 2 according to the positioning holes according to the shape of the steel sheet window to ensure that the steel sheet 3 is flat.

[0056] 3. Through mark point recognition, the solder paste printer adds tin to the area to be soldered, and then performs patching.

[0057] 4. Place the upper cover plate 5 on the steel sheet 3 according to the positioning holes manually or by a mechanical arm.

[0058] 5. Use manual or mechanical means to place the silicone on the upper cover plate 5 according to the positioning holes.

[0059] 6. Place the assembled thermal insulation device on the reflow track for welding.

[0060] The device sinks or opens windows at the device positions of the bottom carrier, steel sheet and upper cover plate on the FPC circuit board to block direct contact and heat conduction between them and the devices on the FPC circuit board, and utilizes the poor thermal conductivity of air to prevent the temperature at the first welding position from being too high and causing secondary tin melting.

[0061] Although the present invention has been specifically shown and described in conjunction with the preferred embodiments, it should be understood by those skilled in the art that various changes may be made to the present invention in form and details without departing from the spirit and scope of the present invention as defined by the appended claims, all of which are within the scope of protection of the present invention.

Claims

1. A secondary reflow nickel sheet insulation device, characterized in that: Including carrier, flexible circuit board, steel sheet, soft thermal insulation material and upper cover; The upper surface of the carrier is sunken to form a first sunken area and a second sunken area; the first sunken area is used to position the flexible circuit board, and its depth is consistent with the thickness of the flexible circuit board; the second welding pad of the flexible circuit board is placed upward, and the second sunken area is used to make way for the first welding device of the flexible circuit board; The steel sheet is magnetizable, and the steel sheet has windows in the area corresponding to the area corresponding to the second welding pad of the flexible circuit board and the area corresponding to the second welding pad; The soft heat-insulating material cooperates with the upper cover plate to open a window in the area corresponding to the second welding pad of the flexible circuit board, and form a closed space above the area corresponding to the second welding pad of the flexible circuit board; A plurality of permanent magnets are embedded in the bottom of the carrier; a plurality of permanent magnets are embedded in the top of the upper cover plate; through the permanent magnets, the steel sheet is attracted to the carrier and the upper cover plate to realize the assembly and fixation of the secondary reflow soldering nickel sheet insulation device.

2. The secondary reflow nickel sheet heat insulation device according to claim 1, characterized in that: The soft heat-insulating material is arranged between the steel sheet and the upper cover plate, and the soft heat-insulating material has a window in the area corresponding to the second welding pad of the flexible circuit board; the upper cover plate has no window in the area corresponding to the second welding pad of the flexible circuit board.

3. The secondary reflow nickel sheet heat insulation device according to claim 1, characterized in that: The soft heat-insulating material is arranged on the upper cover plate, and the soft heat-insulating material has no window in the area corresponding to the second welding pad of the flexible circuit board; the upper cover plate has a window in the area corresponding to the second welding pad of the flexible circuit board.

4. The secondary reflow nickel sheet heat insulation device according to claim 1, characterized in that: The soft heat-insulating material and the upper cover plate are bonded into one piece by high-temperature-resistant glue.

5. The secondary reflow nickel sheet heat insulation device according to claim 1, characterized in that: The soft heat-insulating material is silica gel and has a thickness of 1.5 to 2.5 mm.

6. The secondary reflow nickel sheet heat insulation device according to claim 1, characterized in that: The carrier and the upper cover are made of synthetic stone.

7. The secondary reflow nickel sheet heat insulation device according to claim 1, characterized in that: The thickness of the steel sheet is 0.08-0.20 mm.

8. The secondary reflow nickel sheet heat insulation device according to claim 1, characterized in that: The steel sheet has a window at a MARK point on the second welding surface of the flexible circuit board.

9. The secondary reflow nickel sheet heat insulation device according to claim 1, characterized in that: The steel sheet limits the maximum size of a single window by arranging a pressure strip with a width of 2 to 3 mm in the window area.

10. The secondary reflow nickel sheet heat insulation device according to claim 1, characterized in that: It is also fixed by positioning columns.

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