WO2018181550A1 - Plating process conveyance tape base material, and plating process conveyance tape - Google Patents

Abstract

A base material is provided which is suitable for forming a plating process conveyance tape which is used in a process in which a flexible printed circuit board is bonded, conveyed to a plating tank and plated, and which suppresses shrinkage due to heating during the plating process and suppresses the transfer of an adhesive contained in an adhesive layer onto the flexible printed circuit board. Specifically, this base material is used in the formation of a plating process conveyance tape used in a process in which a flexible printed circuit board is bonded, conveyed to a plating tank and plated, and is characterized in that (1) the base material becomes a plating process conveyance tape by applying an adhesive layer, and (2) the base material is a nonstretch film formed from a single layer or multiple layers, and at least one layer contains polybutylene terephthalate and an inorganic filler.

Description

Plating process transport tape substrate and plating process transport tape

The present invention relates to a plating substrate for transporting a plating process and a tape for transporting a plating process.

When manufacturing a flexible printed circuit board, there are many processes such as alkali development, etching, resist stripping, plating, electronic component mounting, etc. In order to transport a substrate in the manufacturing process to each process, a substrate transport carrier is generally used. It is used. In recent years, a combination of a flexible resin base material and an adhesive layer has also been used as a carrier for transporting a substrate in order to cope with the flexibility of the substrate using a flexible material and the efficiency of the manufacturing process. in use.

For example, Patent Document 1 discloses a substrate carrier used for transporting an object to be transported such as a printed wiring board, which is flexible and bendable, and is fixed on the flexible support. And a specific positioning mask that is deformable to follow when the flexible support is deformed, and that adheres to the lower surface of the substrate so as to be peelable, and that is peelably stuck on the adhesive layer and has a positioning through portion. A carrier for transporting a substrate is disclosed (claim 1 and the like). As the flexible support, for example, it is described that a resin film such as polyimide (PI), polymethyl methacrylate (PMMA), polyethylene naphthalate (PEN), polyethylene terephthalate (PET), polypropylene (PP) can be used. It is described that, for example, urethane resin, polyvinyl alcohol resin, silicone resin and the like can be used as the adhesive layer (paragraph [0015], etc.) (paragraph [0018]) It is described that the substrate is sequentially transferred to a solder cream printing process, an electronic component mounting process, and the like (paragraph [0045]).

JP 2014-72390 A

However, in the process of transporting the flexible printed wiring board to the plating tank using the conventional substrate transporting carrier as disclosed in Patent Document 1, and plating the terminal portion (electrode portion) on the substrate, There's a problem. For example, when a biaxially stretched PET film, a biaxially stretched PEN film, or the like is used as the support for the carrier for transporting the substrate, heating in the plating process (the temperature reaches about 150 to 200 ° C. including heating before and after the plating process). As a result, these films shrink, and there is a problem that curling occurs due to a shrinkage difference from the PI film used for the flexible printed wiring board. Moreover, in the case of a biaxially stretched PEN film, there is also a problem that the film cost is high and difficult to use. Furthermore, when a PI film is used as a support for a substrate carrying carrier in order to reduce the shrinkage difference, there is a problem that the adhesive contained in the adhesive layer is transferred (glue transferred) to the flexible wiring board side.

Therefore, the present invention is a plating process transport tape used in the process of attaching a flexible printed wiring board and transporting it to a plating tank and plating the wiring board, and shrinkage due to heating in the plating process is suppressed. The main object of the present invention is to provide a base material suitable for forming a plating process transport tape in which transfer of the adhesive contained in the adhesive layer to the flexible printed wiring board side is suppressed. Another object of the present invention is to provide a plating process transport tape in which an adhesive layer is provided on the substrate.

As a result of intensive studies to achieve the above object, the present inventors have found that the above object can be achieved by a resin laminate having a specific layer structure, and have completed the present invention.

That is, the present invention relates to the following plating process transport tape substrate and plating process transport tape.
1. A flexible printed wiring board is attached to a plating tank and transported to a plating tank, and used for forming a plating process transport tape used in a process of plating the wiring board,
(1) The substrate becomes the plating process transport tape by providing an adhesive layer;
(2) The base material is an unstretched film consisting of a single layer or multiple layers, and at least one layer contains polybutylene terephthalate and an inorganic filler.
The tape base material for plating process conveyance characterized by the above-mentioned.
2. The tape substrate for transporting a plating process according to Item 1, wherein the layer containing polybutylene terephthalate further contains at least one selected from the group consisting of polyethylene terephthalate, polyethylene naphthalate, polycarbonate, and polybutylene naphthalate. .
3. Item 3. The tape substrate for transporting a plating process according to Item 1 or 2, wherein the inorganic filler contains fibrous potassium titanate.
4). 4. The plating process transport tape according to item 3, wherein the fibrous potassium titanate has an average thickness of 0.1 to 0.8 μm, an average length of 5 to 30 μm, and an average aspect ratio of 10 to 100. Base material.
5). Item 5. The tape substrate for transporting a plating process according to any one of Items 1 to 4, wherein the inorganic filler contains tetrapod-shaped zinc oxide.
6). Item 6. The plating base material for transporting a plating process according to any one of Items 1 to 5, wherein the inorganic filler contains glass fiber.
7). It consists of a layer structure having an outer layer A, an intermediate layer B, and an outer layer C in order,
(1) The intermediate layer B contains the polybutylene terephthalate and the inorganic filler,
(2) The outer layer A and the outer layer C do not contain an inorganic filler,
7. The tape substrate for transporting a plating process according to any one of items 1 to 6.
8). The said outer layer A and the said outer layer C are the tape base materials for a plating process conveyance of said claim | item 7 containing the said polybutylene terephthalate.
9. The outer layer A, the intermediate layer B, and the outer layer C each further contain at least one selected from the group consisting of polyethylene terephthalate, polyethylene naphthalate, polycarbonate, and polybutylene naphthalate. Tape substrate for process conveyance.
10. Item 10. The tape substrate for conveying a plating process according to any one of Items 1 to 9, wherein the tensile elastic modulus is more than 1500 MPa and not more than 2000 MPa.
11. 11. A plating process transport tape comprising an adhesive layer on the surface of the plating process transport tape substrate according to any one of items 1 to 10 above.

The tape substrate for transporting a plating process of the present invention is an unstretched film composed of a single layer or multiple layers, and at least one layer contains polybutylene terephthalate and an inorganic filler, thereby giving an adhesive layer to the substrate. Then, a plating process transport tape is prepared, a flexible printed circuit board is attached, transported to a plating tank, and used in a process of plating the circuit board. ) And the transfer of the adhesive contained in the adhesive layer to the flexible printed wiring board side is suppressed.

It is a cross-sectional schematic diagram which shows an example of the tape base material (a) for plating process conveyance of this invention. In FIG. 1, 1 indicates an intermediate layer B, 2 indicates an outer layer A, and 3 indicates an outer layer C. It is a figure which shows the procedure which forms the tape for plating process conveyance by providing the adhesion layer to the tape base material for plating process conveyance of this invention. Reference numeral 4 denotes an adhesive layer. It is a cross-sectional schematic diagram which shows an example of a layer structure of the plating process conveyance tape (b) of this invention. It is a schematic diagram which shows the aspect which affixes a flexible printed wiring board on the plating process conveyance tape of this invention, rotates a conveyance roll, and conveys.

1. Plating process transport tape base material The plating process transport tape base material of the present invention is a plating process transport tape used in the process of attaching a flexible printed circuit board and transporting it to a plating tank and plating the circuit board. A base material used for forming,
(1) The substrate becomes the plating process transport tape by providing an adhesive layer;
(2) The base material is an unstretched film composed of a single layer or multiple layers, and at least one layer contains polybutylene terephthalate (PBT) and an inorganic filler.
It is characterized by that.

The tape substrate for transporting a plating process of the present invention having the above characteristics is an unstretched film consisting of a single layer or multiple layers, and at least one layer contains PBT and an inorganic filler, whereby an adhesive layer is formed on the substrate. Applying to produce a plating process transport tape, sticking a flexible printed wiring board, transporting it to a plating tank, and using it in the process of plating the wiring board, heating the plating process (about 150-200 ° C) And the transfer of the adhesive contained in the adhesive layer to the flexible printed wiring board side is suppressed.

The tape substrate for transporting a plating process of the present invention may be composed of only a layer containing PBT and an inorganic filler (hereinafter, this layer is also referred to as “main layer”). You may be comprised from the multilayer containing. In addition, it is required that it is a non-stretched film as a whole regardless of whether it is a single layer or a multilayer. Hereinafter, the description will be divided into an embodiment composed of only the main layer and an embodiment composed of a multilayer including the main layer.

(Mode consisting of main layer only)
The main layer contains PBT and an inorganic filler. It is not limited as PBT, A commercial item can be used widely. Intrinsic Viscosity (IV) of PBT is preferably 1 to 1.6 and more preferably 1.1 to 1.3 from the viewpoint of obtaining good fluidity during film formation.

When the intrinsic viscosity is in such a range, moderate fluidity can be imparted to the PBT, so that an unstretched film containing PBT can be easily formed. Moreover, it becomes difficult to generate fish eyes in the non-stretched film containing the formed PBT. The intrinsic viscosity (IV) of PBT in this specification is a value measured according to JIS K7390: 2003.

As the resin component of the main layer, all may be composed of PBT. However, when other resin components (subcomponents) are used in combination, the content of PBT is the main component (100% by mass of the resin component of the main layer). 50% by mass or more), preferably 70% by mass or more, and more preferably 85% by mass or more.

As the subcomponent, at least one of PET, PEN, PC (polycarbonate), PBN (polybutylene naphthalate) and the like can be used. By using such subcomponents together, the stiffness of the plating base material for transporting the plating process can be improved, thereby suppressing the deflection of the transporting tape for the plating process during transportation. In this respect, the stiffness of the base material is preferably about the same as the PI film used as the base material of the flexible printed wiring board, and the tensile elastic modulus is preferably in the range of more than 1500 MPa and not more than 2000 MPa, and 1700 to 2000 MPa. The range of 1850 to 1950 MPa is more preferable. In addition, the tensile elasticity modulus in this specification is the value measured by the method based on JISK7161: 2014. In addition, the combined use of the subcomponents can also suppress the occurrence of undulation and deformation of the substrate surface when the plating process transport tape substrate is heated by heat treatment (for example, about 200 ° C.).

The unstretched PBT film has low shrinkage due to heating compared to biaxially stretched PET and biaxially stretched PEN, and the shrinkage ratio due to heating at about 180 ° C. is about 0.5%. Under the same conditions, the shrinkage rate of the PET film is about 1.2%, and the shrinkage rate of the PEN film is about 0.6%. In the present invention, the main layer contains an inorganic filler described later in addition to PBT, so that the shrinkage due to heating can be further suppressed as compared with the case of not containing the inorganic filler, and the main layer is heated to about 180 ° C. The shrinkage rate due to can be suppressed to the ppm level (substantially 0%). Therefore, the occurrence of curling in the plating process can be suppressed by having a shrinkage rate [ppm level (substantially 0%)] of the PI film used for the flexible printed wiring board.

The inorganic filler is not limited, and a wide range of commercially available products can be used. In addition, since the inorganic filler used in the present invention is used for conveyance in a processing step such as a flexible printed circuit board, the inorganic filler is preferably a material that does not generate contamination during the heat treatment, Those that are not treated (untreated) are preferred. On the other hand, in the case of using a surface-treated product, there is a concern about contamination caused by silicon vaporized during heat treatment for those that are surface-treated with an organic silane such as a silane coupling agent. Avoiding this, it is preferable to use one that has been surface-treated with an inorganic coupling agent such as a titanium coupling agent.

Inorganic fillers have a thermal contraction rate that is an order of magnitude smaller than that of resin components, and the effect of reducing the shrinkage of resin components due to the interfacial adhesive force between resin components and inorganic fillers by kneading into resin components (composite material effect) ) Is obtained. In order to further enhance the effect of the composite material, it is preferable to use a fibrous inorganic filler having a large aspect ratio from the viewpoint of further increasing the suppression of shrinkage due to heating by being contained in the main layer.

The fibrous inorganic filler is not limited, but is preferably a fibrous inorganic filler having a relatively small fiber diameter from the viewpoint of further suppressing the shrinkage caused by heating. Specifically, fibrous potassium titanate is preferable.

The fibrous potassium titanate preferably has an average thickness of 0.1 to 0.8 μm, an average length of 5 to 30 μm, and an average aspect ratio of 10 to 100, and an average thickness of 0.3 to More preferred is 0.6 μm, an average length of 10 to 20 μm, and an average aspect ratio of 10 to 70.

By containing fibrous potassium titanate in such a form, the main layer retains its flexibility and prevents shrinkage due to heating of the main layer (especially shrinkage in the fiber orientation direction) while preventing it from becoming hard and brittle. be able to. As a commercial product of such fibrous potassium titanate, for example, potassium titanate fiber (trade name: “Tismo” series) manufactured by Otsuka Chemical Co., Ltd. is preferable.

In general, when a fibrous inorganic filler is kneaded into a resin, the fibers are oriented in the MD direction (resin flow direction), so the shrinkage suppressing effect in the MD direction becomes very large. Although there is a portion oriented in the TD direction (width direction) to some extent from the flow direction, the shrinkage suppressing effect in the TD direction and the thickness direction is smaller than that in the MD direction. From this point of view, it is preferable to use tetrapod-shaped zinc oxide in which fibers are grown in a three-dimensional direction in order to further suppress the shrinkage caused by heating in the TD direction and the thickness direction of the main layer due to the inclusion of the inorganic filler. .

In other words, it is zinc oxide in which needle-like single crystals are grown radially from the center to the outside like a tetrapod shape, and the same amount of fibrous potassium titanate is used due to the tetrapod shape. In comparison with the case, the suppression of shrinkage due to heating in all directions of the main layer is further increased. In particular, when fibrous potassium titanate and tetrapod-shaped zinc oxide are used in combination, the orientation of fibrous potassium titanate is disturbed by the tetrapod-shaped zinc oxide, not only in the MD direction but also in the TD direction and the thickness direction. Since the existence probability of the oriented fibrous potassium titanate is increased, the shrinkage suppressing effect in all directions is more effectively enhanced.

The tetrapod-shaped zinc oxide preferably has a radially extending single crystal having an average thickness of 0.5 to 5 μm and an average length of 5 to 30 μm, an average thickness of 1 to 3 μm, and an average length of 8 More preferably, it is ˜20 μm. As a commercially available product of such tetrapod-shaped zinc oxide, for example, a zinc oxide single crystal (trade name: “Panatetra”) manufactured by Amtec Co., Ltd. is preferable.

In addition, when glass fiber is used as the inorganic filler, the stiffness of the plating base material for transporting the plating process is improved, thereby suppressing the deflection of the transporting tape for the plating process at the time of transport, in the same manner as the subcomponents described above. be able to. In addition, the occurrence of undulation and deformation of the substrate surface when the plating process transport tape substrate is heat-treated (for example, about 200 ° C.) can also be suppressed.

The average thickness and average length of the inorganic filler are generally specified by observation with an electron microscope.

The content of the inorganic filler contained in the main layer is not limited, but is preferably 3 to 45% by mass, more preferably 5 to 30% by mass in 100% by mass of the main layer. By setting within such a range, the effect of the inorganic filler can be obtained, the flexibility of the main layer can be ensured, the occurrence of folding wrinkles can be suppressed, and hard and brittle can be prevented.

The thickness of the main layer is not limited, but is preferably 10 to 100 μm, more preferably 20 to 70 μm.

The method for producing the main layer is not limited. For example, a resin composition containing a PBT-based resin component and an inorganic filler is prepared, and extruded to a desired thickness by the T-die method or the inflation method. It can manufacture more simply.

The main layer may contain additives such as an antistatic agent, an antiblocking agent, and a slipping agent as long as the effects of the present invention are not impaired.

(Aspect composed of multiple layers including the main layer)
When the tape substrate for transporting the plating process of the present invention is composed of multiple layers including the main layer, the inorganic filler contained in the main layer falls off the main layer during transport and adheres to the flexible printed circuit board. In addition to reducing damage to the mold by the inorganic filler when forming multiple layers by coextrusion film formation, it is mainly from the viewpoint of the balance of the layer structure of the tape base material for plating process conveyance. A layer structure in which the outer layer not containing an inorganic filler is arranged symmetrically so that the layer is an intermediate layer and the intermediate layer is sandwiched between them is preferable.

FIG. 1 is a schematic cross-sectional view showing an example of a tape base material for transporting a plating process of the present invention. Of the base material a in FIG. 1, 1 is an intermediate layer B, 2 is an outer layer A, and 3 is an outer layer C. . With such a layer configuration, in addition to being able to suppress the inorganic filler from falling off from the intermediate layer B which is the main layer, curling generation during or after film formation is suppressed from the viewpoint of layer structure balance. be able to.

The intermediate layer B which is the main layer is as described above.

The outer layer A and the outer layer C preferably do not contain any inorganic filler. The resin component of the outer layer A and the outer layer C is not limited, but the resin component of the outer layer A and the outer layer C is the intermediate layer in that the three layers of the intermediate layer B, the outer layer A, and the outer layer C are easily formed by extrusion. Like B, PBT is preferably the main component.

That is, all the resin components of the outer layer A and the outer layer C may be composed of PBT, but when other resin components (subcomponents) are used in combination, out of 100% by mass of the resin component of the outer layer A and the outer layer C, The PBT content is preferably the main component (50% by mass or more), particularly preferably 70% by mass or more, and more preferably 85% by mass or more. As the subcomponent, at least one of PET, PEN, PC, PBN and the like can be used. In the present invention, when the intermediate layer B contains PBT and the subcomponent, it is preferable that both the outer layer A and the outer layer C contain PBT and the subcomponent in the same manner as the intermediate layer B. From the viewpoint of the structural balance, it is preferable that the resin compositions of the intermediate layer B, the outer layer A, and the outer layer C are the same apart from the presence or absence of the inorganic filler.

In addition, it is preferable not to contain PI as a resin component of the outer layer A and the outer layer C. When PI is contained and the content is large, the material is the same as or close to the PI film used for the flexible printed circuit board, so when an adhesive layer is applied and used as a plating process transport tape, There is a possibility that the adhesive contained in the adhesive layer may transfer (glue transfer) to the flexible printed wiring board side.

When the tape substrate for transporting a plating process of the present invention is composed of the three layers, the thickness of the outer layer A is not limited, but is preferably 3 to 30 μm, more preferably 5 to 15 μm. The thickness of the intermediate layer B is not limited, but is preferably 5 to 60 μm, more preferably 10 to 50 μm. The thickness of the outer layer C is not limited, but is preferably 3 to 30 μm, more preferably 5 to 15 μm. In addition, it is preferable that the thicknesses of the outer layer A and the outer layer C are the same in terms of the layer configuration balance.

Further, the ratio of the layer thicknesses in the case of the three-layer structure is preferably in the range of outer layer A: intermediate layer B: outer layer C = 1: 1: 1 to 1: 15: 1, and 1: 2: 1 to 1: 8. A range of: 1 is more preferred. In the case of a three-layer structure, the total thickness is preferably 10 to 100 μm, more preferably 20 to 70 μm.

Although the manufacturing method of the said resin laminated body is not limited, For example, each resin composition for forming the outer layer A, the intermediate | middle layer B, and the outer layer C is prepared, and three layers are extrusion-molded by the T-die method or the inflation method. It can manufacture more simply. In addition, after preparing each film of the outer layer A, the intermediate | middle layer B, and the outer layer C separately, it can also form by bonding each film by the dry lamination using a well-known adhesive agent. Both layers and the resin laminate are unstretched films by any manufacturing method.

2. Plating Process Transport Tape The plating process transport tape substrate of the present invention described above can be used as a plating process transport tape b by providing an adhesive layer 4 as shown in FIGS. Specifically, a plating process transport tape is obtained by having an adhesive layer on the surface of the plating process transport tape substrate. Usually, an adhesive layer may be formed on one side of the tape substrate for transporting the plating process.

The method for applying the adhesive layer is not limited, and the adhesive layer can be formed by applying a known adhesive to the surface of the plating process transport tape substrate.

Examples of the pressure-sensitive adhesive for forming the pressure-sensitive adhesive layer include rubber-based pressure-sensitive adhesives, acrylic pressure-sensitive adhesives, urethane-based pressure-sensitive adhesives, and polyvinyl ether-based pressure-sensitive adhesives. Among these, acrylic pressure-sensitive adhesives are preferable.

Examples of the acrylic resin constituting the acrylic pressure-sensitive adhesive include a polymer of (meth) acrylic acid alkyl ester and a copolymer of (meth) acrylic acid alkyl ester and a monomer copolymerizable therewith. Etc. In addition, (meth) acryl means methacryl or acryl.

Examples of the (meth) acrylic acid alkyl ester include methyl (meth) acrylate, ethyl (meth) acrylate, butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, octyl (meth) acrylate, ( (Meth) acrylic acid isononyl and the like, and a (meth) acrylic acid alkyl ester in which the homopolymer has a glass transition temperature of −50 ° C. or lower is preferable. In addition, as a pressure-sensitive adhesive that hardly changes even in a heat treatment near 200 ° C., butyl (meth) acrylate is preferable among alkyl (meth) acrylates.

Examples of monomers copolymerizable with (meth) acrylic acid alkyl esters include (meth) acrylic acid such as hydroxyethyl (meth) acrylate, hydroxybutyl (meth) acrylate, and hydroxyhexyl (meth) acrylate. Hydroxyalkyl ester, (meth) acrylic acid glycidyl ester, (meth) acrylic acid, itaconic acid, maleic anhydride, (meth) acrylic acid amide, (meth) acrylic acid N-hydroxymethylamide, dimethylaminoethyl methacrylate, t- (Meth) acrylic acid alkylaminoalkyl esters such as butylaminoethyl methacrylate, vinyl acetate, styrene, acrylonitrile and the like.

The thickness of the adhesive layer is not limited, but is preferably 1 to 30 μm, and more preferably 5 to 20 μm.

The plating process transport tape of the present invention thus obtained is attached to the adhesive layer with the flexible printed wiring board 6 in the manufacturing process as shown in FIG. 4, for example, and is transported to the plating tank by rotating the transport roll 5. And the process of plating to the said wiring board can be performed. It can be used not only for transporting to the plating tank but also for transporting to other processes as long as the durability of the transport tape is not affected.

Hereinafter, the present invention will be described in detail with reference to examples and comparative examples. However, the present invention is not limited to the examples.

Examples 1, 3, 4, 9, 10 and Comparative Examples 1 to 4
Examples 1, 3, and 4 and Comparative Examples 1 to 4 have only the intermediate layer B.

The resin component and the inorganic filler were introduced into the extruder of the extruder so as to have the composition shown in Table 1, and melt-kneaded.

Extrusion was performed at 250 ° C. so that the thickness of the intermediate layer B was 40 μm.

An adhesive layer having a thickness of 10 μm was applied to the intermediate layer B.

Thereby, a tape base material for plating process conveyance was obtained.

Examples 2, 5 to 8, 11, 12
Examples 2, 5 to 8, 11, and 12 have an outer layer A, an intermediate layer B, and an outer layer C.

In each extruder of the three-layer extruder, the resin component and the inorganic filler were added so that each of the outer layer A, the intermediate layer B, and the outer layer C had the composition shown in Table 1, and melt-kneaded.

The three layers were coextruded by an inflation method at 250 ° C. so that the thickness ratio of each of the outer layer A, the intermediate layer B, and the outer layer C was outer layer A: intermediate layer B: outer layer C = 1: 3: 1, and the thickness was 40 μm. A resin laminate was obtained.

A 10 μm thick adhesive layer was applied to the outer layer A side.

Thereby, a tape base material for plating process conveyance was obtained.

Evaluation of each plating process transport tape (presence or absence of curling)
Adhesive layer is formed by applying glue (acrylic adhesive “Arontack S-1601” manufactured by Toagosei Co., Ltd.) to each plating process transport tape base material, and a flexible printed wiring board is attached and heated (about 200 ° C. × The presence or absence of curling at the time of 5 minutes) was visually observed.

The case where no curling was observed was evaluated as “◎”, the case where there was some curling but within the allowable range was evaluated as “◯”, and the case where remarkable curling was recognized was evaluated as “x”.
(With or without glue transfer)
Applying glue (Acrylic adhesive “Arontack S-1601” manufactured by Toagosei Co., Ltd.) to the tape base material for transporting each plating process to form an adhesive layer, and after attaching a flexible printed circuit board, The presence or absence of glue transfer to the flexible printed circuit board side was visually observed.

The case where paste transfer was not recognized was evaluated as “◯”, and the case where paste transfer was observed was evaluated as “X”.
(Heat-resistant)
The presence or absence of waving or deformation of the substrate surface after heat treatment (200 ° C. × 5 minutes) was performed on each of the plating process transport tape substrates.

A case where no waviness or deformation was observed was evaluated as “◯”, and even if some of these were recognized, a case that was within the allowable range in actual use was evaluated as “Δ”, and a case that did not satisfy the allowable range was evaluated as “X”.
(Good or bad)
The stiffness of each plating process transport tape substrate was evaluated by the tensile elastic modulus (MPa).

When the tensile elastic modulus exceeded 1500 MPa, the evaluation was ○, and when the tensile modulus was 1500 MPa or less and 900 MPa or more, Δ was evaluated, and 900 MPa or less was evaluated as ×.

Each evaluation result is shown in Table 1.

As is clear from the results in Table 1, in the plating process transport tapes of Examples 1 to 12 that satisfy the predetermined requirements, the occurrence of curling when the heat treatment is performed after forming the adhesive layer is suppressed, and the adhesive layer is formed. The occurrence of subsequent glue transfer was also suppressed. In Examples 1, 2, 4 to 12, the shrinkage in the MD direction is suppressed by using the fibrous inorganic filler, and the level at which the shrinkage in the TD direction is also required is suppressed. In Examples 3 to 12, the use of a tetrapot-like inorganic filler suppresses not only the MD direction but also the TD direction and the thickness direction, and more preferable shrinkage suppression is achieved. Further, in Examples 7 and 8, in each of the outer layer A, the intermediate layer B, and the outer layer C, the stiffness of the film is improved and the heat resistance is improved by using PEN and PC in addition to PBT. .

On the other hand, the plating process conveyance tapes of Comparative Examples 1 to 4 that do not satisfy the predetermined requirements are inferior to Examples 1 to 12 in evaluation of curling or glue transfer. In particular, curling occurred in Comparative Examples 1 and 2 where the intermediate layer B did not contain an inorganic filler, and curling also occurred in Comparative Example 3 where the intermediate layer B did not contain both PBT and inorganic filler. On the other hand, in Comparative Example 4 in which PI is used for the intermediate layer and no inorganic filler is contained, curling is suppressed in that it is the same material as the PI film of the flexible printed wiring board. Transition is permitted.

PBT: Mitsubishi Engineering Plastics “Novaduran 5050CS”
PEN film: “Teonex Q51” manufactured by Teijin DuPont Films
PET film: Teijin Tetron Film G2 manufactured by Teijin DuPont
PI film: "Kapton 50H" manufactured by Toray DuPont
PEN (for blend): “Teonex TN8065S” manufactured by Teijin DuPont
PC (for blend): “Panlite L-1250Y” manufactured by Teijin DuPont
PBN (for blending): Teijin DuPont PET (for blending): Bell Polyester Products "Bellpet DFG1"
Potassium titanate: “Tismo Tismo N (fiber diameter: 0.3 to 0.6 μm, fiber length: 10 to 20 μm)” manufactured by Otsuka Chemical Co., Ltd.
Zinc oxide: “Panatetra WZ-0531 (average fiber length: about 10 μm, tetrapod shape)” manufactured by Amtec Corporation
Glass fiber: “PF E-100 (no surface treatment)” manufactured by Nittobo

a. Tape substrate for transporting plating process b. Plate process tape 1. Middle layer B
2. Outer layer A
3. Outer layer C
4). 4. Adhesive layer 5. Transport roll Flexible printed circuit board

Claims (11)

1. A flexible printed wiring board is attached to a plating tank and transported to a plating tank, and used for forming a plating process transport tape used in a process of plating the wiring board,
   (1) The substrate becomes the plating process transport tape by providing an adhesive layer;
   (2) The base material is an unstretched film consisting of a single layer or multiple layers, and at least one layer contains polybutylene terephthalate and an inorganic filler.
   The tape base material for plating process conveyance characterized by the above-mentioned.
2. 2. The plating base material for transporting a plating process according to claim 1, wherein the layer containing polybutylene terephthalate further contains at least one selected from the group consisting of polyethylene terephthalate, polyethylene naphthalate, polycarbonate, and polybutylene naphthalate. .
3. The said inorganic filler is a tape base material for plating process conveyance of Claim 1 or 2 containing fibrous potassium titanate.
4. The plating process transport tape according to claim 3, wherein the fibrous potassium titanate has an average thickness of 0.1 to 0.8 µm, an average length of 5 to 30 µm, and an average aspect ratio of 10 to 100. Base material.
5. The plating base material for transporting a plating process according to any one of claims 1 to 4, wherein the inorganic filler contains tetrapod-shaped zinc oxide.
6. The plating base material for transporting a plating process according to any one of claims 1 to 5, wherein the inorganic filler contains glass fiber.
7. It consists of a layer structure having an outer layer A, an intermediate layer B, and an outer layer C in order,
   (1) The intermediate layer B contains the polybutylene terephthalate and the inorganic filler,
   (2) The outer layer A and the outer layer C do not contain an inorganic filler,
   The tape substrate for transporting a plating process according to any one of claims 1 to 6.
8. The said outer layer A and the said outer layer C are the tape base materials for a plating process conveyance of Claim 7 containing the said polybutylene terephthalate.
9. 9. The plating according to claim 8, wherein each of the outer layer A, the intermediate layer B, and the outer layer C further contains at least one selected from the group consisting of polyethylene terephthalate, polyethylene naphthalate, polycarbonate, and polybutylene naphthalate. Tape substrate for process conveyance.
10. The tape substrate for transporting a plating process according to any one of claims 1 to 9, wherein the tensile elastic modulus is more than 1500 MPa and not more than 2000 MPa.
11. A plating process transport tape having an adhesive layer on the surface of the plating process transport tape substrate according to any one of claims 1 to 10.

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