CN114364159A - Reflow Soldering Fixtures for Flexible Circuit Boards - Google Patents

Abstract

The invention discloses a reflow soldering jig for a flexible circuit board, which is applied to a reflow soldering process of a PET base film flexible circuit board and comprises a cover plate and a support bottom, wherein the cover plate and the support bottom are respectively positioned on the front side and the back side of the flexible circuit board; the cover plate is provided with at least one group of hollow holes for welding; the surface of the cover plate is coated with heat insulation paper to form a first heat insulation layer; the surface of the support bottom is wrapped with heat insulation paper to form a second heat insulation layer, and the first heat insulation layer and the second heat insulation layer are directly attached to and extruded on the front surface and the back surface of the flexible circuit board during welding; carry out inseparable laminating to the flexible line way board respectively through first insulating layer and second insulating layer, heat the processing of accomplishing welding position promptly to the fretwork hole, the welded in-process effectively insulates against heat to the flexible line way board for the heat is concentrated in welding position, can not disperse to around, and then guarantees to use PET to guarantee the planarization as base film flexible line way board, can not take place deformation, solves the problem that appears in the current.

Description

Reflow Soldering Fixtures for Flexible Circuit Boards

technical field

The invention relates to the field of reflow soldering fixtures, in particular to a reflow soldering fixture for flexible circuit boards.

Background technique

The flexible circuit board is a kind of highly reliable and excellent flexible circuit made of polyimide or polyester film as the base material through the die-cutting process. It can be moved and retracted freely in three-dimensional space, so as to achieve the integration of component assembly and wire connection.

In the process of producing flexible circuit boards, the circuit assembly technology of soldering and assembling by reflow soldering method requires the use of a jig to assist in the accurate positioning of high-temperature solder paste by performing SMT on the base film. Welding; and polyester film PET has the advantages of high insulation and low price, which is attracting more and more manufacturers to try to use PET as the base material to produce flexible circuit boards, but the temperature resistance of the PET base material is only 180 ℃, using the melting temperature of 235-250℃ in the process of reflow soldering at high temperature solder paste, most of the existing reflow soldering fixtures include a cover plate and a support plate, the cover plate and the support plate are fastened together, and The cover plate is provided with welding holes, which are used to accurately melt the high-temperature solder paste to realize welding with the metal sheet. However, since the PET substrate is directly attached to the middle of the cover plate and the support plate, the cover plate Most of them are metal materials. During the welding process, the heat is dissipated to the cover plate and the support plate, so that the PET base film is deformed at high temperature due to the thermal shrinkage effect, and the flexible circuit board is damaged. The main reason for the damage is the deformation caused by high temperature. And the product becomes brittle; therefore, a new type of reflow soldering fixture is urgently needed, which is suitable for the preparation of flexible die-cutting circuit boards applied to PET as a base film.

SUMMARY OF THE INVENTION

In view of the deficiencies in the above technologies, the present invention provides a reflow soldering fixture for a flexible circuit board, which includes a cover plate and a support base, the support base and the cover plate are attached and connected, and are respectively extruded and attached to the flexible circuit board. On both sides, the hollow hole is adapted to the welding position of the flexible circuit board. During the welding process, the heat insulation board and the first heat insulation layer effectively insulate the flexible circuit board, so that the heat is concentrated at the welding position and will not be dissipated. To the surrounding, and then to ensure that PET is the base film flexible circuit board to ensure the flatness, no deformation and brittle products, and solve the existing problems.

In order to achieve the above purpose, the present invention provides a reflow soldering fixture for a flexible circuit board, which is applied in the reflow soldering process of a PET base film flexible circuit board, and includes a cover plate and a support bottom, and the cover plate and the support bottom are respectively located on the flexible circuit board. The cover plate is provided with at least one set of hollow holes for welding; the surface of the cover plate is covered with heat insulating paper to form the first heat insulating layer; the surface of the support bottom is wrapped with heat insulating paper to form the first heat insulating layer. Two thermal insulation layers, when welding, the first thermal insulation layer and the second thermal insulation layer are directly extruded on the front and back sides of the flexible circuit board.

Preferably, the thermal insulation paper is made of mica paper as a base material, glass fiber cloth as a reinforcing material, and a high temperature resistant silicone resin is selected.

Preferably, the cover plate includes a heat insulating plate and a connecting plate, and the heat insulating plate and the connecting plate are connected by fixing bolts.

Preferably, the material of the heat insulating board and the bottom is synthetic stone.

Preferably, the connecting plate is made of metal.

Preferably, a plurality of sets of magnet units are evenly arranged on the heat insulating plate, the cover plate and the connecting plate are magnetically attracted by the magnet units; the cover plate and the connecting portion are reinforced and connected by a screw structure.

Preferably, a plurality of sets of magnetic holes for accommodating magnetic elements are provided on the side of the cover plate away from the support base.

Preferably, a base is also included, and the support base is abutted with the side of the base away from the cover plate.

Preferably, the base is further provided with a plurality of sets of fixing holes for fixed connection with the outside world.

Preferably, a holding position for aligning the flexible circuit board is provided on the side of the support bottom close to the flexible circuit board.

The beneficial effects of the invention are: compared with the prior art, a reflow soldering fixture for a flexible circuit board, which is applied to the reflow soldering process of a PET base film flexible circuit board, includes a cover plate and a support bottom, a cover plate and a support plate. The bottom is located on the front and back sides of the flexible circuit board respectively; the cover plate is provided with at least one group of hollow holes for welding; the surface of the cover plate is covered with heat insulating paper to form a first heat insulation layer; the surface of the support bottom is covered with Insulation paper to form the second insulation layer. During welding, the first insulation layer and the second insulation layer are directly attached and extruded on the front and back sides of the flexible circuit board; during the welding process, the first insulation layer The flexible circuit board is effectively insulated by the layer and the second heat insulation layer, so that the heat is concentrated at the welding position and will not be dissipated to the surroundings, thereby ensuring the flatness of the flexible circuit board with PET as the base film, and no deformation and product become brittle and solve existing problems.

Description of drawings

Fig. 1 is the exploded view of the present invention;

Fig. 2 is the base and the support bottom matching diagram of the present invention;

Fig. 3 is the base plan view of the present invention;

Fig. 4 is the enlarged view of A area of the present invention;

FIG. 5 is an enlarged view of the B region of the present invention.

6 is a schematic structural diagram of the first thermal insulation layer and the cover plate of the present invention;

FIG. 7 is a schematic diagram of the second heat insulating layer and the support base of the present invention.

The main component symbols are explained as follows:

1. Cover plate; 11. Hollow hole; 12. Insulation plate; 13. Connecting plate; 14. Magnet unit; 2. Bottom support;

21. Insulation layer; 22. Magnetic hole; 23. Holding position; 3. Base; 31. Fixing hole;

4. The first thermal insulation layer; 5. The second thermal insulation layer.

Detailed ways

In order to express the present invention more clearly, the present invention will be further described below with reference to the accompanying drawings.

In order to make the purposes, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments These are some embodiments of the present invention, but not all embodiments. The components of the embodiments of the invention generally described and illustrated in the drawings herein may be arranged and designed in a variety of different configurations.

Thus, the following detailed description of the embodiments of the invention provided in the accompanying drawings is not intended to limit the scope of the invention as claimed, but is merely representative of selected embodiments of the invention. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

It should be noted that like numerals and letters refer to like items in the following figures, so once an item is defined in one figure, it does not require further definition and explanation in subsequent figures.

In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. The indicated orientation or positional relationship is based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship that the product of the invention is usually placed in use, only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying The device or element referred to must have a particular orientation, be constructed and operate in a particular orientation, and therefore should not be construed as limiting the invention. Furthermore, the terms "first", "second", "third", etc. are only used to differentiate the description and should not be construed as indicating or implying relative importance.

Furthermore, the terms "horizontal", "vertical", "overhanging" etc. do not imply that a component is required to be absolutely horizontal or overhang, but rather may be slightly inclined. For example, "horizontal" only means that its direction is more horizontal than "vertical", it does not mean that the structure must be completely horizontal, but can be slightly inclined.

In the description of the present invention, it should also be noted that, unless otherwise expressly specified and limited, the terms "arrangement", "installation", "connection" and "connection" should be understood in a broad sense, for example, it may be a fixed connection, It can also be a detachable connection or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, or the internal communication between the two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood in specific situations.

Most of the existing reflow soldering fixtures include a cover plate and a support plate, the cover plate and the support plate are fastened together, and the cover plate is provided with welding holes, and the welding holes are used to accurately melt the high-temperature solder paste. Then, the welding with the metal sheet is realized. However, since the PET base material is directly attached to the middle of the cover plate and the support plate, and the cover plate is mostly made of metal material, the heat is dissipated to the cover plate and the support plate during the welding process. Therefore, a new type of reflow soldering fixture is urgently needed, which is suitable for PET is used as a base film for the preparation of flexible die-cut circuit boards.

In order to solve the existing problems, the present invention provides a reflow soldering fixture for a flexible circuit board, which is applied in the reflow soldering process of a PET base film flexible circuit board. Please refer to FIG. 1 to FIG. 7 , including a cover plate 1 and a The support base 2, the cover plate 1 and the support base 2 are respectively located on the front and back sides of the flexible circuit board; the cover plate 1 is provided with at least one set of hollow holes 11 for welding, and the front side of the hollow holes 11 is chamfered by 2.5mm. The solder paste part of the pre-applied nickel sheet that needs to be exposed by reflow soldering ensures that the solder paste exposed in the high temperature airflow can be melted instantly, so that the nickel sheet is well welded on the flexible circuit board. And other areas of the flexible circuit board are protected and insulated to avoid adverse effects such as deformation of the flexible circuit board with PET as the base material due to high temperature; Insulation layer 4; the surface of the base 2 is wrapped with insulation paper to form a second insulation layer 5. During welding, the first insulation layer 4 and the second insulation layer 5 are directly attached and extruded on the flexible circuit board It can be understood that the welding position is an important electrical position of the flexible circuit board in actual use, and nickel sheets, solder paste, conductive layer and base film are respectively provided from top to bottom. The welding position is heated by the air blowing, and the solder paste is heated and dissolved, and then it is firmly welded with the nickel sheet. During this process, the hot air will also act on the base film indirectly. If PET is used as the base film, the traditional cover plate and the base are in During the high temperature blowing process, it also absorbs some heat and acts to increase its own temperature, which in turn makes the PET base film around the welding position deformed due to the high temperature, and the yield is further reduced, and the PET base film has a significant price advantage and should not be discarded. In the present invention, during operation, the flexible circuit board is placed on the bottom of the support, directly attached to the second heat insulation layer 5, and the hollow hole 11 is used to align the welding position. When the hot air heats the welding position, it is located at the top. The first heat insulating layer 4 at the end blocks the heat, the first heat insulating layer is attached to the second heat insulating layer, and the hot air avoids the deformation of the PET base film due to the heating of the fixture, and the preheating in the air is not effective. It will cause the cover plate 1 or the support bottom 2 to heat up, so that only the hollow hole 1 is heated to complete the welding position processing. During the welding process, the flexible circuit board is effectively insulated, so that the heat is concentrated in the The welding position will not radiate to the surroundings, thereby ensuring the flatness of the PET-based flexible circuit board, without deformation and brittle products, solving the existing problems;

Specifically, the thermal insulation paper is made of mica paper as the base material, glass fiber cloth as the reinforcing material, and high temperature resistant silicone resin is selected; mica paper is selected as the base material, and the glass fiber cloth is used as the reinforcing material. High temperature resistant silicone resin is used for bonding, and the rolled insulating material is baked, dried, pressed and rolled at high temperature. The heat insulating layer 4 and the second heat insulating layer 5; the cover plate 1 includes a heat insulating plate 12 and a connecting plate 13, and the heat insulating plate 12 and the connecting plate 13 are connected by fixing bolts; the materials of the heat insulating plate 1 and the bottom 4 are: Synthetic stone material; when used in practical applications, the thermal insulation board 12 and the first thermal insulation layer 4 form good thermal insulation, and also have excellent temperature resistance and low thermal conductivity (thermal conductivity is 0.25w/m*k) , so that when it is used as a reflow soldering fixture, it can maintain its characteristics of avoiding deformation at high temperature and good heat insulation effect, so that PET will not be deformed due to high temperature (250℃) baking during the reflow soldering process. , and the flexible circuit board is pressed by the connecting plate 13, so that the flatness of the flexible circuit board is ensured during the winding process; in the existing, usually in order to reduce costs, if PET is used as the base film, there is no thermal insulation. Under the circumstance, the cover plate attached to the flexible circuit board is directly transferred to the PET when it is heated, and then the flexible circuit board is deformed to a certain extent, and the low-temperature solder paste is used for welding. In terms of welding ability, the welding tensile capacity of high-temperature solder paste generally reaches 30N, while the welding tensile capacity of low-temperature solder paste is less than 15N, and its welding firmness is less than that of high-temperature solder paste. The synthetic stone is used as the material of the cover plate 1 and the bottom plate 2, so that the flexible circuit boards using PET as the base film can effectively use high temperature solder paste for reflow soldering process, which solves the industry's problems.

In this embodiment, the heat insulating plate 12 and the connecting plate 13 are connected by fixing bolts; the heat insulating plate 12 and the connecting plate 13 are provided with suitable connecting holes, and the heat insulating plate 12 and the connecting plate 13 are firmly fixed by the fixing bolts In the production process, the cover plate 1 can be separately provided with multiple groups, and the support bottom is effectively pressed through the combination of multiple groups to form a jig, which can realize The staff can quickly clean up or repair, so that the preparation work or finishing work can be carried out smoothly.

More specifically, the connecting plate 13 is made of metal material; the heat insulating plate 12 is evenly provided with a plurality of sets of magnet units 14, and the heat insulating plate 12 and the connecting plate 13 are magnetically attracted by the magnet units 14, in order to further make the cover plate and connecting plate For fixing, add a screw structure for connection; the side of the heat shield 12 away from the support base 2 is provided with multiple sets of magnetic holes 21 for accommodating magnetic components; in actual work, the connecting plate 13 is made of metal, and the heat shield There are multiple sets of magnet units 14, and the magnet units 14 are adsorbed and attached to the connecting board through the magnetic attraction effect; in order to strengthen the pressing ability of the fixture to the flexible circuit board in actual use, there are multiple sets of The magnetic hole 21 for accommodating the magnetic element can be glued to the magnetic element by high temperature glue in the magnetic hole 21. The magnetic element is preferably selected as a cylindrical magnet with a diameter of 3 cm, the interval between the cylindrical magnets is 10 cm, and the thickness of the corresponding support bottom is set to 4 cm , to ensure that there is enough depth to accommodate the cylindrical magnet, and the magnet unit 14 is also mutually attracted to the connecting plate, so as to apply pressure to the flexible circuit board with PET as the base material, ensuring that the PET is used as the base material. The flexible circuit board as the base material is not easily deformed during reflow soldering, which increases the flatness of the PET-based flexible circuit board and solves the problem of warping caused by various external factors.

In this embodiment, a base 3 is also included, and the support base 2 is attached to the side of the base 4 away from the cover plate; the support base 2 is also provided with a plurality of groups of fixing holes for fixed connection with the outside world; the support base is mainly used to connect the base 3. The support is carried out so that there will be no deviation of the position, and the external device is fixedly connected through the fixing hole, so that there will be no displacement during the work, and the welding position accuracy of the reflow soldering process is guaranteed; in practice, According to the actual situation, the bottom can also be covered with thermal insulation paper.

In this embodiment, a holding position 22 for aligning the flexible circuit board is provided on the side of the support base 2 close to the flexible circuit board; the holding position 22 is used to limit the position of the flexible circuit board, specifically according to the flexible circuit In the groove where the board fits, the holding position 22 cooperates with the cover plate 1 to completely cover and close the flexible circuit board housed in the holding position, so that the welding position will not be offset, and the welding precision effect is improved.

The advantages of the present invention are:

1) The flexible circuit board is placed in the holding position, so that the hollow hole is aligned with the welding position, the first heat insulation layer and the second heat insulation layer are respectively closely attached to the flexible circuit board, and the hollow hole is heated. That is, the processing of the welding position is completed, and the flexible circuit board is effectively insulated during the welding process, so that the heat is concentrated at the welding position and will not be dissipated to the surroundings, thereby ensuring that the PET-based flexible circuit board ensures the flatness and does not Deformation occurs and the product becomes brittle to solve existing problems;

2) There are multiple sets of magnetic holes for accommodating magnetic elements at the lower end of the support. By bonding the magnetic elements with high temperature glue in the magnetic holes, the magnetic elements and the magnet unit are attracted to the connecting plate, which increases the flexibility of the circuit. The flatness of the board avoids the problem of product warping.

The above disclosures are only a few specific embodiments of the present invention, but the present invention is not limited thereto, and any changes that can be conceived by those skilled in the art should fall within the protection scope of the present invention.

Claims (10)

1. A reflow soldering jig for a flexible circuit board is applied to a reflow soldering process of a PET base film flexible circuit board and is characterized by comprising a cover plate and a support base, wherein the cover plate and the support base are respectively positioned on the front side and the back side of the flexible circuit board; the cover plate is provided with at least one group of hollow holes for welding; the surface of the cover plate is coated with heat insulation paper to form a first heat insulation layer; the surface of the support bottom is wrapped with heat insulation paper to form a second heat insulation layer, and the first heat insulation layer and the second heat insulation layer are directly attached to the front surface and the back surface of the flexible circuit board during welding.

2. The reflow soldering jig for the flexible circuit board according to claim 1, wherein the heat insulation paper is compounded by using mica paper as a base material, glass fiber cloth as a reinforcing material and high temperature resistant organic silicon resin.

3. The reflow soldering jig for a flexible wiring board according to claim 1, wherein the cover plate comprises a heat insulating plate and a joint plate, and the heat insulating plate and the joint plate are connected by fixing bolts.

4. The reflow soldering jig for the flexible circuit board according to claim 3, wherein the heat insulation board and the base are made of synthetic stone.

5. The reflow soldering jig for a flexible circuit board according to claim 3, wherein the connection plate is made of metal.

6. The reflow soldering jig for the flexible circuit board according to claim 3, wherein the heat insulation board is uniformly provided with a plurality of groups of magnet units, and the cover plate and the connecting plate are magnetically attracted through the magnet units; the cover plate and the joint part are connected in a reinforcing mode through a screw structure.

7. The reflow soldering jig for the flexible circuit board according to claim 5, wherein a plurality of sets of magnetic holes for accommodating the magnetic elements are formed in the surface of the cover plate away from the support base.

8. The reflow soldering jig for the flexible circuit board according to claim 1, further comprising a base, wherein the support base is attached to one surface of the base, which is far away from the cover plate.

9. The reflow soldering jig for the flexible circuit board according to claim 8, wherein the base further has a plurality of sets of fixing holes for fixedly connecting with the outside.

10. The reflow soldering jig for the flexible circuit board according to claim 1, wherein a holding position for aligning the flexible circuit board is provided on a surface of the support base close to the flexible circuit board.

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