FDC thermoforming process with pet as base film

Abstract

The application discloses a FDC hot-press forming process with PET as a base film, and comprises the following main steps: after obtaining a coiled material, hot setting glue is coated on one side of a first PET base film and a second PET base film, and is respectively adhered to the front and back surfaces of a copper foil; the semi-finished product after being pressed by a heating roller is sent to a hot-press treatment to obtain a formed FDC; a proper torque of a reel is selected to generate a proper tension when the coiled material is adhered, so that the first PET base film and the second PET base film are adhered to the front and back surfaces of the copper foil, and the hot setting glue is solidified through a proper hot-press temperature, so that the flatness of the PET base film is not damaged, the edge lifting caused by the thermoplastic deformation due to heating is effectively prevented, and the problems of the edge lifting and the uneven surface of the semi-finished product in the stage caused by the unreasonable process of the heating and pressing are solved.

Description

TECHNICAL FIELD

[0001] The application belongs to the field of FDC preparation, and particularly relates to an FDC hot-press forming process with PET as a base film. BACKGROUND

[0002] Flexible die-cutting circuit (FDC) is a kind of circuit with high reliability and excellent flexibility, which is made of flexible film as a base material through a die-cutting process, and has the characteristics of free bending, folding and winding, and can be moved and stretched in three-dimensional space, so as to achieve the integration of component assembly and wire connection.

[0003] With resource integration and product development, flexible die-cutting circuit is widely used in the preparation process of new energy field vehicles to carry electronic components, therefore, the demand side requires that the FDC product has the characteristics of large size, sealing and flexibility, and PET or PI material is used as a base film to cover the upper and lower surfaces of the flexible conductive layer to realize the flexibility requirement of the FDC, and among the two materials used as the base film, PET has obvious price advantage, high insulation and flexibility compared with PI, and is concerned in the field.

[0004] However, in the preparation process of the FDC with PET as a base material, the heat setting glue is usually solidified by heating and pressing, so as to firmly locate the copper foil between the two PET base films, and in the preparation process, due to the poor temperature resistance of PET, the unreasonable process in the hot-pressing stage will cause the FDC to have the problems of edge lifting and uneven surface in the front forming stage, which seriously affects the subsequent processing, therefore, an FDC hot-press forming process with PET as a base film is needed to solve the above problems. SUMMARY

[0005] In the above-mentioned technology, when PET is used as a base film to prepare FDC, due to the poor high-temperature resistance of the PET base film, the product is prone to have the problems of edge lifting and unevenness during high-temperature heat treatment, and the application controls and adjusts the torque and tension of die-cutting forming, adjusts the process and temperature time of hot-pressing, and specially processes the reflow soldering jig, so that the prepared FDC flexible circuit board with PET base material has the characteristics of high flatness and excellent performance, and better meets the use requirements of customers.

[0006] The purpose of the application is achieved by the following scheme:

[0007] An FDC hot-press forming process with PET as a base film, comprising the following steps:

[0008] A: providing a roll material, the material being copper foil, first PET base film and second PET base film;

[0009] B: coating heat setting glue on one side of the first PET base film and the second PET base film, and bonding to the front and back of the copper foil; when laminating, the winding shaft torque of the first PET base film, the second PET base film and the copper foil is 8-15 N·m; the semi-finished product after bonding is rolled by a heating roller, the rolling pressure is 10-15 kg / cm 2 , and the rolling temperature is 125-135℃;

[0010] C: sending the semi-finished product after heating and rolling to heat pressing treatment, the heat pressing temperature is 180℃, the heat pressing pressure is 150 kg, and the pressing maintaining time is 150 s, to obtain a shaped FDC.

[0011] Preferably, in step A, a circuit is formed on the copper foil.

[0012] Preferably, in step B, the rolling pressure is 10 kg / cm 2 , and the rolling temperature is 130℃.

[0013] Preferably, in step B, the winding shaft torque of the PET and the copper foil is 12 N·m.

[0014] Preferably, in step C, before the heat pressing treatment, a curing treatment is further needed, the curing treatment: curing the cut FDC, the curing temperature is 65-75℃, and the time is 3.5-4.5 h.

[0015] Preferably, in step C, the heat pressing treatment temperature is 180℃, the heat pressing pressure is 150 kg, and the pressing maintaining time is 150 s.

[0016] The FDC heat pressing forming process with PET as base film provided by the present application has the following steps: A: providing a roll material, the material being copper foil, first PET base film and second PET base film; B: coating heat setting glue on one side of the first PET base film and the second PET base film, and bonding to the front and back of the copper foil; when laminating, the winding shaft torque of the first PET base film, the second PET base film and the copper foil is 8-15 N·m; the semi-finished product after bonding is rolled by a heating roller, the rolling pressure is 10-15 kg / cm 2, the temperature of the roller pressing is 125-135 DEG C; C: the semi-finished product after the heating roller pressing is sent to the hot pressing treatment, the hot pressing temperature is 180 DEG C, the hot pressing pressure is 150 kg, the pressure maintaining time is 150 s, the shaped FDC is obtained; the proper winding shaft torque is selected to make the winding material adhesive, proper tension is generated, the first PET base film and the second PET base film are adhered on the front and back surfaces of the copper foil, the thermosetting glue is solidified through the reasonable hot pressing temperature, the flatness of the PET base film is not damaged, the edge warping caused by the thermoplastic deformation is effectively prevented, and then the problems of the edge warping and the uneven surface of the FDC in the front end shaping stage caused by the unreasonable heating and pressing process are solved. BRIEF DESCRIPTION OF DRAWINGS

[0017] Figure 1 The process flow chart of the present application. DETAILED DESCRIPTION

[0018] In order to more clearly illustrate the present application, the present application is further described below in conjunction with the accompanying drawings.

[0019] In the following description, details of specific examples are given to provide a more thorough understanding of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, and not all the embodiments. It should be understood that the specific embodiments are only used to explain the present application, and not to limit the present application.

[0020] It should be understood that when the terms "comprising" and / or "including" are used in the specification, it means that the features, integers, steps, operations, elements, or components listed after the terms are present, but not excluding the presence or addition of one or more other features, integers, steps, operations, elements, components, or combinations thereof.

[0021] In the prior art, the main manufacturing process of the FDC includes: round knife die cutting forming → curing → hot pressing → baking → gold plating / OSP → PLASMA → FR4 reinforcement → curing → code spraying → tin paste brushing → SPI detection → SMT patching → reflow soldering → spot welding → AOI detection → X-RAY detection → dispensing → UV curing → electrical measurement → glue sticking / labeling; among them, the three stages of round knife die cutting forming, curing and hot pressing can be classified as the hot pressing forming stage of the base film, and as the initial process, the hot pressing forming stage of the base film needs to reserve the circuit for electrical conduction and the hole for assembling or carrying electronic components, so the appearance requirement of the FDC in this stage is particularly important, if the FDC appears appearance problems after forming, such as uneven surface, the subsequent patching will be misaligned, and if the edge warping occurs, the solidification of the thermosetting glue will be poor, the displacement between the base film and the copper foil will occur, and then through a reasonable process, the shaped FDC with good appearance parameters is prepared, so as to facilitate the subsequent processing, which is urgently needed by the industry.

[0022] To solve the above technical problems, the present application provides a FDC hot forming process with PET base film, please refer to Figure 1 , comprising the following steps:

[0023] A: providing a coiled raw material, the raw material being copper foil, first PET base film and second PET base film;

[0024] B: coating thermosetting glue on one side of the first PET base film and the second PET base film, and pressing the first PET base film and the second PET base film to the two sides of the copper foil by heating the press roller; when the first PET base film, the second PET base film and the copper foil are loaded on the reel, the torque is 8-15 N·m; the semi-finished product after bonding is rolled by heating the press roller, the pressure of rolling is 10-15 kg / cm 2 , and the temperature of rolling is 125-135℃;

[0025] C: sending the semi-finished product after heating and rolling to hot pressing treatment, the hot pressing temperature is 180℃, the hot pressing pressure is 60-150 kg, and the pressure holding time is 150 s, to obtain the shaped FDC;

[0026] By selecting the appropriate torque of the reel, the appropriate tension is generated when the coiled raw material is bonded, so that the first PET base film and the second PET base film are bonded to the front and back sides of the copper foil, and the thermosetting glue is cured by a reasonable hot pressing temperature, which ensures that the flatness of the PET base film will not be damaged, effectively preventing the edge lifting caused by the thermal plastic deformation due to heating. Finally, the semi-finished product to be hot pressed is hot pressed by a hot press, so that the thermosetting glue can be further cured to obtain the shaped FDC, thereby solving the problem of edge lifting and uneven surface of the FDC in the front forming stage due to the unreasonable process of heating and pressing in the prior art.

[0027] More specifically, in step A, the copper foil is formed into a circuit; there are many methods for forming a circuit, and those skilled in the art can prepare it by etching, cutting, etc.

[0028] More specifically, in step B, the thermosetting glue is laid in the first PET base film and the second PET base film to coat the circuit formed by the copper foil, avoiding the exposure of the copper foil to the air and thus oxidation; the heating temperature of the heating press roller is the initial setting temperature of the thermosetting glue, and if the temperature is too high, the bubbles of the thermosetting glue will not be easily discharged, which will affect the local oxidation of the copper foil; since the rolling is performed at a temperature of 125-135℃, the first PET base film and the second PET base film will become soft due to their own material, and if the pressure of rolling is not within this appropriate range, it will seriously affect the appearance flatness and size of the product.

[0029] More specifically, in step B, the torque of the PET and copper foil loaded on the reel is 8-15 N·m; it can be understood that the torque of the reel is adjusted to obtain appropriate tension of the PET and copper foil during lamination, and if the tension of the PET and copper foil at this stage is not matched, the flatness of the lamination between the copper foil and the PET will be seriously affected, and lamination wrinkles are prone to occur.

[0030] More specifically, in step C, a curing treatment is required before the hot pressing treatment, and the curing treatment is to cure the cut FDC, the curing temperature is 65-75℃, and the time is 3.5-4.5h; since the heat-set adhesive is selected as the adhesive, if the product is directly subjected to the hot pressing treatment, bubbles or copper foil separation from the base film are prone to occur due to the high temperature, and the upper limit of the temperature of the subsequent hot pressing process is increased by the curing treatment to reduce bubble generation.

[0031] The application will be described in detail below with reference to specific examples:

[0032] The following coiled material raw materials are selected: the thickness of the first PET base film and the second PET base film is 0.05mm; the copper foil is a calendered copper foil, and the thickness is 0.05mm; the thickness of the laid heat-set adhesive is 0.03mm; the first and second waste films are both PET materials; it can be understood that the examples are divided into first part examples and second part examples: the first part examples are mainly to distinguish the appearance of the semi-finished product sample after preliminary pressing by the heating roller; the second part examples are to detect the parameters of the formed FDC sample after the hot pressing treatment, and compare them with the standard parameters established by the state;

[0033] First part examples:

[0034] Example 1

[0035] A: Provide coiled material raw materials, and the raw materials are copper foil for forming a circuit, a first PET base film and a second PET base film;

[0036] B: Coat heat-set adhesive on one side of the first PET base film and the second PET base film, and press the first PET base film and the second PET base film to cover both sides of the copper foil by a heating roller to obtain a first hot-pressed FDC; during lamination, the copper foil, the first PET base film and the second PET base film are roller-pressed by the heating roller, the roller-pressing pressure is 5kg / cm 2 , and the temperature is 130℃; the torque of the PET and copper foil loaded on the reel shaft is 8N·m, and a semi-finished product sample 1 to be subjected to hot pressing treatment is obtained.

[0037] Example 2

[0038] A: Provide coiled material raw materials, and the raw materials are copper foil for forming a circuit, a first PET base film and a second PET base film;

[0039] B: hot melt adhesive is coated on one side of the first PET base film and the second PET base film, and the first PET base film and the second PET base film are pressed by a heating roller to be attached to both sides of the copper foil to obtain the first hot-pressed FDC; during the attachment, the copper foil, the first PET base film and the second PET base film are heated and rolled by the heating roller, the rolling pressure is 10 kg / cm 2 , the temperature is 130°C; the PET and copper foil roll shaft torque is 8 N·m, and the semi-finished product sample 2 to be hot-pressed is obtained.

[0040] Example 3

[0041] A: providing roll stock, the stock is a copper foil for forming a circuit, a first PET base film and a second PET base film;

[0042] B: hot melt adhesive is coated on one side of the first PET base film and the second PET base film, and the first PET base film and the second PET base film are pressed by a heating roller to be attached to both sides of the copper foil to obtain the first hot-pressed FDC; during the attachment, the copper foil, the first PET base film and the second PET base film are heated and rolled by the heating roller, the rolling pressure is 15 kg / cm 2 , the temperature is 130°C; the PET and copper foil roll shaft torque is 8 N·m, and the semi-finished product sample 3 to be hot-pressed is obtained.

[0043] Example 4

[0044] A: providing roll stock, the stock is a copper foil for forming a circuit, a first PET base film and a second PET base film;

[0045] B: hot melt adhesive is coated on one side of the first PET base film and the second PET base film, and the first PET base film and the second PET base film are pressed by a heating roller to be attached to both sides of the copper foil to obtain the first hot-pressed FDC; during the attachment, the copper foil, the first PET base film and the second PET base film are heated and rolled by the heating roller, the rolling pressure is 20 kg / cm 2 , the temperature is 130°C; the PET and copper foil roll shaft torque is 8 N·m, and the semi-finished product sample 1 to be hot-pressed is obtained.

[0046] The appearance of the samples 1 to 4 obtained above is detected, and the results are shown in Table 1.

[0047] Table 1

[0048]

[0049] As can be seen from Table 1, the appearance of the samples obtained is different according to the rolling pressure of the heating roller, in sample 1, the rolling pressure is 10 kg / cm2 The sample 1 appears delamination phenomenon, the preliminary guess is that the pressure of the center area is not enough when pressing, which leads to the first PET base film or the second PET base film cannot effectively adhere to the copper foil, and then delamination occurs; the pressure of the roller pressing is kept at 20 kg / cm 2 When the pressure is too large, combined with the uneven internal stress generated by the PET when heated and rolled, the corresponding bending and wrinkling phenomenon occurs, and further affects the effective adhesion of the edge part, and the edge lifting phenomenon occurs in succession; therefore, the roller pressure of 10-15 kg / cm 2 is more appropriate, preferably 10 kg / cm 2 as the roller pressure parameter in the following examples and the second part of the example.

[0050] Example 5

[0051] A: Provide coiled raw materials, the raw materials are copper foil, first PET base film and second PET base film for forming circuit;

[0052] B: Spread and coat heat-setting glue on one side of the first PET base film and the second PET base film, and press the first PET base film and the second PET base film by heating roller to adhere to both sides of the copper foil to prepare the first hot-pressed FDC; when adhering, the copper foil, the first PET base film and the second PET base film are heated and rolled by the heating roller, the roller pressure is 10 kg / cm 2 , and the temperature is 130°C; the PET and copper foil coiled shaft torque loaded is 5 N·m, and the semi-finished product sample 5 to be hot-pressed is obtained.

[0053] Example 6

[0054] A: Provide coiled raw materials, the raw materials are copper foil, first PET base film and second PET base film for forming circuit;

[0055] B: Spread and coat heat-setting glue on one side of the first PET base film and the second PET base film, and press the first PET base film and the second PET base film by heating roller to adhere to both sides of the copper foil to prepare the first hot-pressed FDC; when adhering, the copper foil, the first PET base film and the second PET base film are heated and rolled by the heating roller, the roller pressure is 10 kg / cm 2 , and the temperature is 130°C; the PET and copper foil coiled shaft torque loaded is 8 N·m, and the semi-finished product sample 6 to be hot-pressed is obtained.

[0056] Example 7

[0057] A: Provide coiled raw materials, the raw materials are copper foil, first PET base film and second PET base film for forming circuit;

[0058] B: hot melt adhesive is coated on one side of the first PET base film and the second PET base film, and the first PET base film and the second PET base film are pressed by a heating roller to be attached to both sides of the copper foil to obtain the first hot-pressed FDC; during the attachment, the copper foil, the first PET base film and the second PET base film are heated and rolled by the heating roller, the rolling pressure is 10 kg / cm 2 , the temperature is 130°C; the PET and copper foil roll shaft torque is 12 N·m, and the semi-finished product sample 7 to be hot-pressed is obtained.

[0059] Example 8

[0060] A: providing roll stock, the stock being a copper foil for forming a circuit, a first PET base film and a second PET base film;

[0061] B: hot melt adhesive is coated on one side of the first PET base film and the second PET base film, and the first PET base film and the second PET base film are pressed by a heating roller to be attached to both sides of the copper foil to obtain the first hot-pressed FDC; during the attachment, the copper foil, the first PET base film and the second PET base film are heated and rolled by the heating roller, the rolling pressure is 10 kg / cm 2 , the temperature is 130°C; the PET and copper foil roll shaft torque is 15 N·m, and the semi-finished product sample 8 to be hot-pressed is obtained.

[0062] Example 9

[0063] A: providing roll stock, the stock being a copper foil for forming a circuit, a first PET base film and a second PET base film;

[0064] B: hot melt adhesive is coated on one side of the first PET base film and the second PET base film, and the first PET base film and the second PET base film are pressed by a heating roller to be attached to both sides of the copper foil to obtain the first hot-pressed FDC; during the attachment, the copper foil, the first PET base film and the second PET base film are heated and rolled by the heating roller, the rolling pressure is 10 kg / cm 2 , the temperature is 130°C; the PET and copper foil roll shaft torque is 18 N·m, and the semi-finished product sample 9 to be hot-pressed is obtained.

[0065] The appearance detection items of the above obtained samples 6 to 9 are detected, and the obtained results are as shown in Table 2.

[0066] Table 2

[0067]

[0068] It can be seen from Table 2 that when the torque of the reel for containing the material is in the range of 8-15 N·m, the material is better adhered, the appearance size does not change, and there is no bending and wrinkling phenomenon; the torque of the reel can determine the tension of the material during conveying and processing, and when the torque is below 8 N·m or higher than 15 N·m, the appearance size is larger or smaller, bending and wrinkling phenomenon occurs, it is preliminarily speculated that under the condition of variable heating edge roller pressing, the stress inside the PET changes, the PET shows certain thermoplasticity, and after leaving the heating roller pressing, it quickly returns to the equilibrium state, if the torque of the reel is not in a suitable range at this time, the PET is pulled or excessively pulled, resulting in deformation of the first PET base film and the second PET base film during adhesion, and thus a greater impact on the appearance; however, it is known to those skilled in the art that the PET base film will easily deform at about 120℃, which is not conducive to the process, however, through experiments, the appearance of the sample prepared under the torque and pressure of the above-mentioned embodiments can also maintain a high degree of flatness without edge curling phenomenon; in order to further explore in the solidification process, therefore, the reel torque parameter is limited to 8-15 N·m, and 12 N·m is preferred as the torque parameter of the second part of the embodiments.

[0069] Second part of the embodiment:

[0070] Example 10

[0071] A: providing a roll material, the material being a copper foil for forming a circuit, a first PET base film and a second PET base film;

[0072] B: coating a thermosetting adhesive on one side of the first PET base film and the second PET base film, and pressing the first PET base film and the second PET base film by heating the pressure roller to adhere to both sides of the copper foil to prepare a first hot-pressed FDC; during adhesion, the copper foil, the first PET base film and the second PET base film are heated and pressed by the heating pressure roller, the roller pressure is 10 kg / cm 2 , the temperature is 130℃; the torque of the PET and copper foil reel shaft loaded is 12 N·m;

[0073] C: sending the semi-finished product after heating and pressing to an oven for curing treatment: curing the cut FDC, the curing temperature is: 65-75℃, and the time is: 4.5h.

[0074] After completing the curing treatment, it is sent to a hot press for hot pressing, the hot pressing temperature is: 180℃, the hot pressing pressure is: 60kg, and the pressing maintenance time is: 150s, to obtain a shaped FDC sample 10;

[0075] Example 11

[0076] A: providing a roll material, the material being a copper foil for forming a circuit, a first PET base film and a second PET base film;

[0077] B: hot melt adhesive is coated on one side of the first PET base film and the second PET base film, and the first PET base film and the second PET base film are pressed by a heating roller to be attached to both sides of the copper foil to obtain a first hot-pressed FDC; during the attachment, the copper foil, the first PET base film and the second PET base film are heated and pressed by the heating roller, the roller pressure is 10 kg / cm 2 , the temperature is 130°C; the torque of the PET and copper foil roll shaft is 12 N·m;

[0078] C: the semi-finished product after the heating and pressing is sent to an oven for curing treatment; the cut FDC is cured, the curing temperature is 65-75°C, and the curing time is 4.5 h.

[0079] After the curing treatment is completed, the hot-pressing temperature is 180°C, the hot-pressing pressure is 150 kg, the pressing time is 150 s, and a shaped FDC sample 11 is obtained.

[0080] Example 12

[0081] A: providing a roll material, the material is a copper foil for forming a circuit, a first PET base film and a second PET base film;

[0082] B: hot melt adhesive is coated on one side of the first PET base film and the second PET base film, and the first PET base film and the second PET base film are pressed by a heating roller to be attached to both sides of the copper foil to obtain a first hot-pressed FDC; during the attachment, the copper foil, the first PET base film and the second PET base film are heated and pressed by the heating roller, the roller pressure is 10 kg / cm 2 , the temperature is 130°C; the torque of the PET and copper foil roll shaft is 12 N·m;

[0083] C: the semi-finished product after the heating and pressing is sent to an oven for curing treatment; the cut FDC is cured, the curing temperature is 65-75°C, and the curing time is 4.5 h.

[0084] After the curing treatment is completed, the hot-pressing temperature is 180°C, the hot-pressing pressure is 240 kg, the pressing time is 150 s, and a shaped FDC sample 12 is obtained.

[0085] Comparative Example 1

[0086] A: providing a roll material, the material is a copper foil for forming a circuit, a first PET base film and a second PET base film;

[0087] B: hot melt adhesive was coated on one side of the first PET base film and the second PET base film, and the first PET base film and the second PET base film were pressed to adhere to both sides of the copper foil by a heating roller, to obtain a first hot-pressed FDC; during the adhesion, the copper foil, the first PET base film and the second PET base film were heated and rolled by the heating roller, the rolling pressure was 20 kg / cm 2 , and the temperature was 130°C; the torque of the PET and copper foil roll shaft was 12 N·m;

[0088] C: the semi-finished product after the heating rolling was sent to an oven for curing treatment; the cut FDC was cured, the curing temperature was 65-75°C, and the curing time was 4.5 h.

[0089] After the curing treatment, the hot pressing was carried out in a hot press, the hot pressing temperature was 180°C, the hot pressing pressure was 150 kg, the pressing maintaining time was 150 s, and the comparative sample 1 was obtained.

[0090] Comparative sample 2:

[0091] A: providing a roll material, the material was a copper foil for forming a circuit, a first PET base film and a second PET base film;

[0092] B: hot melt adhesive was coated on one side of the first PET base film and the second PET base film, and the first PET base film and the second PET base film were pressed to adhere to both sides of the copper foil by a heating roller, to obtain a first hot-pressed FDC; during the adhesion, the copper foil, the first PET base film and the second PET base film were heated and rolled by the heating roller, the rolling pressure was 10 kg / cm 2 , and the temperature was 130°C; the torque of the PET and copper foil roll shaft was 5 N·m;

[0093] C: the semi-finished product after the heating rolling was sent to an oven for curing treatment; the cut FDC was cured, the curing temperature was 65-75°C, and the curing time was 4.5 h.

[0094] After the curing treatment, the hot pressing was carried out in a hot press, the hot pressing temperature was 180°C, the hot pressing pressure was 150 kg, the pressing maintaining time was 150 s, and the comparative sample 2 was obtained.

[0095] The above samples 10 to 12 were detected, and the results were as shown in Table 3.

[0096] Table 3

[0097]

[0098] It can be seen from Table 3 that the appearance parameters of samples 10 to 12 all have good performance. In the pressing project, the peel strength of the obtained samples 10 to 12 is tested. According to common knowledge, the peel strength required for the sample at this stage is ≥17.78 N / inch, and samples 10 to 12 are much better than this index. The pressing force of sample 11 and sample 12 is different, but the peel strength values of sample 11 and sample 12 are less different, the linear curve is relatively flat, and even shows a downward trend. The power required by the flat pressing equipment when running at high pressure is higher than that at low pressure. Based on further cost consideration, 150 kg is used as the hot pressing pressure parameter. In Comparative Example 1, the pressure of the heating roller is not in the optimal range, and the flatness problem occurs in the appearance project. Although the peel strength is far from the standard, it is far less than the peel strength of samples 10 to 12 in the present application. In Comparative Example 2, the torque of the coiled material is not in the optimal range, and in the appearance project test, the surface flatness cannot be kept flat, and the edge curling and warping phenomenon also occurs, and the peel strength in the pressing project is also much smaller than that of samples 10 to 12. According to common knowledge, the parameter of peel strength mainly depends on the stage of complete curing of the hot solid glue by the flat pressing machine, and it is generally believed that the early stage of lamination process pays more attention to the alignment between the PET base film and the copper foil. However, it can be seen from the example data and comparative example data in Table 3 that under the appropriate torque parameter and heating roller pressure parameter, the peel performance of FDC can also be significantly improved.

[0099] The advantages of the present application are:

[0100] When the first PET base film and the second PET base film are bonded to the two sides of the copper foil, the temperature of the heating roller, the torque of the feeding reel and the subsequent hot pressing treatment are provided with clear parameter schemes, so that the formed FDC is stable in shape, the surface is flat, and the drawing force is much higher than the reference value given by the national operation standard.

[0101] The above disclosure is only a few specific embodiments of the present application, but the present application is not limited thereto. Any changes that can be thought of by those skilled in the art shall fall within the scope of the present application.

Claims

1. A FDC thermoforming process with a PET base film, characterized in that, The method comprises the following steps: A: providing a copper foil, a first PET base film and a second PET base film; B: coating the first PET base film and the second PET base film on one side with thermosetting glue, and pressing the first PET base film and the second PET base film to the two sides of the copper foil by heating and pressing roller to obtain the first hot-pressed FDC; when the first PET base film, the second PET base film and the copper foil are attached, the torque of the reel shaft of the first PET base film, the second PET base film and the copper foil is 8-15 N·m; the pressure of the roller pressing is 10-15 kg / cm 2 , and the temperature of the roller pressing is 125-135℃; C: sending the first hot-pressing FDC to a hot-pressing treatment, the hot-pressing temperature is 180℃, the hot-pressing pressure is 90-240kg, the pressure maintaining time is 150s, and a shaped FDC is obtained.

2. The FDC thermoforming process with PET base film according to claim 1, characterized in that, In step A, the copper foil needs to be formed into a circuit first.

3. The FDC thermoforming process with PET base film according to claim 1, characterized in that, In step B, the pressure of the rolling was 10 kg / cm 2 and the temperature of the rolling was 130°C.

4. The FDC thermoforming process with PET base film according to claim 1, characterized in that, In step B, the torque of the PET and copper foil loaded roll shafts is 12N·m.

5. The FDC thermoforming process with PET base film according to claim 1, characterized in that, In step C, before the hot-pressing treatment, a curing treatment is further needed, the curing treatment is that the cut FDC is cured, the curing temperature is 65-75℃, and the time is 3.5-4.5h.

6. The FDC thermoforming process with PET base film according to claim 1, characterized in that, In step C, the hot-pressing treatment temperature is 180℃, the hot-pressing pressure is 150kg, and the pressure maintaining time is 150s.

Images