JPH0327018B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application] A number of mold release sheets have been proposed to facilitate the removal of molded laminate structures from the moldings with which they were formed. Such a release sheet includes
Includes single layer sheets, multilayer sheets and coated sheets. For example, in U.S. Pat. No. 3,507,733,
It has been suggested that polypropylene layers on kraft paper or cellophane are suitable for making floor and wall coverings. Additionally, U.S. Patent No.
No. 3,700,537, aluminum foil kraft paper composites are disclosed for creating embossed laminates. The present invention relates to such a molded release sheet and a method for manufacturing the same.

[Prior Art] In addition to the technology described in the aforementioned patent publication, U.S. Pat. It has been suggested that thermoplastic materials such as polyester materials may be used as release sheets under certain molding conditions.

U.S. Pat. No. 4,166,150 discloses a release sheet with a cured coating, and U.S. Pat. Nos. 4,243,461 and 4,263,073 disclose
Various methods have been disclosed for making release sheets.

PROBLEM TO BE SOLVED BY THE INVENTION Molded release sheets have been proposed for the processing and fabrication of epoxy laminates and multilayer circuit board laminates. For example, the Tedlar product mentioned above is used as a release sheet for epoxy multilayer circuit boards. The present invention aims to provide a new structure for such a release sheet.

SUMMARY OF THE INVENTION Broadly speaking, the present invention comprises a polyester, nylon, or acetyl cellulose film and a layer or coating of release resin material on at least one side of the film, and the invention comprises a polyester, nylon, or acetyl cellulose film and a layer or coating of release resin material on at least one side of the film, provides molded release sheet structures used in Preferably, both sides of the film are coated to form a three layer sheet structure. The film is first formed on (1) the surface of the laminate, including clad and unclad surfaces, (2) metal forming equipment, and (3) any other forming device used in the forming operation. Chemically, mechanically or electrically (corona discharge) treated on one or more sides to improve the adhesion of the coated release material, which has the property of easily separating from the auxiliary sheet or layer.
Laminated structures include laminated components used to make multilayer laminates such as printed circuit boards and other laminates. The present invention is also directed to a method of manufacturing a release sheet structure.

The polyester, nylon or acetyl cellulose used as the substrate or support layer is thermally stable and coatable, with high service temperatures, good dimensional stability, high tensile strength and a smooth surface. This is a feature of the present invention. Moreover, such films have good lay-down properties and are readily available at low prices.

It is a further feature of the present invention that the release coating can be applied to the film with a weave pattern that acts to create a mirror (i.e., inverse) pattern on the unclad surface of the laminate component. The textured surface will aid in bonding between the laminated components in multilayer fabrication.

Now, referring to Figure 1, 0.127~0.0127mm
(0.005 to 0.0005 inches), preferably having a thickness of about 0.0234 mm (0.00092 inches) (and a width selected to be suitable for handling by the processing equipment used) 8 (ICI America's Melinex)
422, Melinex S, or similar)
is fed from the feed roll 10 to the corona treatment station 13 through drive rolls 11,12. Here, Melinex is a polyester material formed from polyethylene terephthalate. Polyester film is hydrophobic. As an alternative, a nylon film can be used that has the required coating material receptivity and heat resistance.
In particular, any film made from nylon 66 polymer has been found to be useful. 66 nylon polymer comprises a polymer that is a condensation product of adipic acid and hexamethylene diamine. The film contains additives that give it high heat resistance. The polymer also has a specific gravity of approximately 1.13. Such a nylon film (preferably about 1
~4 mil (0.0254-0.102mm) thick)
It has a melting temperature of approximately 266℃ (510℃). Furthermore, film 8 is an acetyl cellulose film, in particular a triacetate cellulose film HP- manufactured by Courtaulds CPD.
550AA is also fine.

Corona treatment station 13 (ENI model RS-
96 powered, Deerpark, Inc. DP-9018 processing station) includes a roller electrode 16 (see FIG. 2) covered with a dielectric insulating cover 17, and a linear electrode 18. Electrode 18 and cover 1
The gap 19 between 7 and 7 is about 1.02 to 2.03 mm (about
0.040~0.080inch). High frequency-high voltage power supply 20
As the film 8 passes through the gap 19,
A corona discharge is emitted from the linear electrode 18 to the roller electrode 16 to treat the film surface to a dyne level of about 72. This treatment makes the surface of the film more receptive to later applied release coatings. The processed film 8 is fed to a winding intermediate roll 15 or to a subsequent station, which will be described later. Alternatively, the film may be treated by other means such as chemical, mechanical or other treatment means to promote satisfactory adhesion.

The purpose of treating the film surface by corona discharge and other means is to promote the adhesion of the coating material to the film while improving the wettability of the surface.

Referring now again to FIG. 1, the second feed roll pair 21, 22 transports the film 8 to the next coating station 23, where an engraved intaglio roll 24 is placed in a coating bath in a storage tank 27. Mobil chemical, a curable acrylic resin from 26 to
No. 82XE087 manufactured by Inmont or Inmont
Pick up a coating material such as No.NBE1102 manufactured by Corporation Chemical. Mobil's products are acrylic oligomers or resins containing acrylic epoxies or acrylic urethanes. Such coatings may also be diluted with acrylate monomers or other monomers such as N-vinylpyrrolidone to reduce viscosity. The coating material may include a fade agent, a release additive, a clay, and a pigment. The intaglio roll 24 transfers the coating material to a rubber transfer roll 29, which transfers the coating material to the surface of the film 8. The intaglio roll 24 has a number of eroded chambers on its surface so that a uniform, predetermined amount of coating is applied. The amount of coating material can be varied by using different intaglio rolls,
This affects the overall shape of the surface of the support layer or sheet being coated. 28 is a backup roll. In order to obtain the desired pattern on the support sheet, intaglio rolls having different numbers of chambers per unit area may be used. In addition to offset gravure printing, techniques for coating film 8 include direct gravure printing and Meyer rod.
or the use of multiple smooth rolls where the amount of coating is determined by setting the air gap between the two coating rolls. Preferably, the present invention requires only about 0.31 to 2.72 Kg, preferably 1.36 to 1.81 Kg (about 1.5 to 6, preferably 3 to 4 pounds) per 3000 square feet of film surface. , giving a thin coating.

The coated film 8 then enters an electron beam curing station 31 where the applied coating is cured. Station 31 is
Upper and lower compartments 32a, 32b and electron acceleration chamber 33
and a power source 36.
Contains 2. Referring to FIG. 3, the electron acceleration chamber 33 has a tubular beam control device 3 therein.
7, the beam control device 37 includes a linear electron beam element 38 mounted on an extension arm 39. Electron beam element 3
8 emits a curtain of electrons (indicated by lines 40) downwardly through a window 41 in the upper compartment 32a. Alternatively, a point (or "pencil") emits a beam of electrons that is scanned or swept over the coated film.
type electrode scanner can be used. Bombardment of the coated film with electrons initiates a polymerization process in the coating and forms a dry, wrinkle-free product. It has been found that the radiation dose required to cure the coating on the moving film 8 is typically in the range of 1.5 to 3.0 megarads. As cured, the coating on the film side has a distinct weave pattern that acts to form or impart an inverse pattern to the surface of the adjacent laminate of the product being molded.

The film after being cured is taken up by a winding roll 35.
rolled on top. The film 8 is then treated a second time to coat its opposite side, but since a second pass through the corona treatment station worsens the release performance of the initially formed coating, the following Processed in the following steps.

1 First, the film is passed through a corona treatment station to treat only one side.

2 The film is flipped over and passed through the corona treatment station to treat the second side, coated and cured in a continuous manner to provide a cured coating on the second side. Ru.

3. The film is turned over again, placed on the feed roll 25 (FIG. 1), and the first
coating and electron beam curing station 2 to provide a cured coating on the side of the
3, 31 (not corona treatment).

Following this treatment, the film is passed through the corona only once with a coating placed thereon to avoid redundant corona treatment of the coating layer.

Alternatively, corona treatment is accomplished by employing an additional corona treatment station 13a (FIG. 2a) to treat both sides of the sheet 8 in one pass. If station 13a is used, it is preferably inserted just before or after corona treatment station 13 in the process of FIG. Station 13a is the same as station 13 except that it is on either side to process the bottom side of film 8.

The present invention is directed to the manufacture of laminate components and to the fabrication of multilayer laminate products. The lamination component is 1
Used to construct multilayer laminates consisting of two or more laminate components. The laminate component may include one side that is clad, two sides that are clad, or no side that is clad. Sheets of prepreg material are used both in the manufacture of laminate components and to attach one laminate component to another in multilayer fabrication.

Advantages of this release sheet structure for use in the manufacture of laminate components (such as FR-4 type laminates) used in circuit boards and other industries include:
(1) become soft, shrink, or become brittle;
28-70Kg/cm ² without emitting odor
171-188℃ (340-370〓) for 30-60 minutes (or more) under pressure of (400-1000psi)
(2) substantially inert ability to prevent adverse effects on the chemical, electrical or physical performance of the adjacent laminate; (3) the product pressed against it; (4) strength to permit easy peeling after completion of the molding operation; (5) resistance to various conditions including extreme heat, pressure, and time. having excellent releasability from adjacent surfaces containing epoxy resins even when encountering difficult molding conditions;
(6) For the unclad surface of the laminated part,
These include the ability to impart a matte finish, textured texture or controlled gloss.

The use of release sheet structures according to the present invention in multilayer manufacturing includes the following additional advantages. That is, the release sheet structure: (i) does not stick to either crud, prepreg sheets, kraft sheets, or laminate surfaces;

(ii) Helps prevent migration of material that can flow from one laminate component to another.

(iii) Does not shrink.

(iv) Not brittle.

(v) Has high tensile strength.

(vi) be sufficiently rigid for handling;

(vii) Does not emit excessive odors.

(viii) Easily removed from molded products and molds because static electricity is minimized.

(ix) Good hole formation characteristics by drilling or punching.

The texture on the surface of the release sheet structure is created by the amount of coating applied, the rheology of the coating, and the method of transferring the coating onto the film support layer. The release sheet structure of the present invention also improves the unclad surface of an epoxy-glass laminate by reducing the height of the glass ridges (i.e., protrusions) on the surface of the laminate. This effect of the release sheet structure creates a resin-rich characteristic for the rough surface of the epoxy resin plus glass, as if it had more epoxy resin and less glass on the surface. It works like it did.

Finally, referring to FIG. 4, a mold 45 is shown for molding the laminate section. Mold 45
are press platens 49, 51; metal mesh plate 52,
53 and 54; kraft sheet 55 for pattern formation or to aid in heat transfer; other laminate-building layers 56 used in laminate component production; and laminate-building layer 56 and press platens 49, 51 and screen plates 52, 53. and 54, the coated release sheet structure 57, 5 of the present invention is selectively inserted between
8, 59 and 60. Release sheet structures 57, 58, 59, and 60 are larger in area than one laminate-building layer 56 to prevent transfer of molten resin material 61 from one laminate-building layer 56 to another. .

[Example] A roll of Melinex 442 film having a width of 1.372 m (54″) and a thickness of 0.023 mm (0.00092″) was
One side of it was passed through a corona treatment station 13 for treatment. The film is then flipped over and passed through the corona treatment station again to treat the other side, and then passed through a coating station 23 and an electron beam curing station 31.
A textured and cured coating of No. 82XE087 resin material was formed on one side of the film.

The coated film was flipped over to form a similar cured coating on the other side.

In the manufacture of laminates, including printed circuit boards (PCBs), the components to be laminated are first created using molding techniques, and then such components are molded together with other laminates to form the final product. be done. The molded release sheet structure of the present invention is also useful in many laminate molding operations using press platens with or without mesh plates.

[Brief explanation of the drawing]

FIG. 1 is a schematic front view showing the manufacturing process of a molded release sheet structure including a corona treatment and electron beam curing station; FIG. 2 is a front view of the corona treatment station; FIG.
FIG. 3 is a front view of the corona treatment station;
1 is a cross-sectional view of the electron beam curing station taken along line 3--3 in FIG. 1; and FIG. 4 is an exploded front view of a lamination mold using the release sheet of the present invention. 8: Film, 10: Feed roll, 11,1
2: Drive roll, 13, 13a: Corona treatment station, 15: Intermediate roll, 16: Roller electrode, 17: Insulating cover, 18: Linear electrode, 19:
Gap, 20: Power supply, 21, 22: Feed roll, 2
3: coating station, 24: intaglio roll, 25: feeding roll, 26: coating tank,
27: Storage tank, 28: Backup roll,
29: Transfer roll, 31: Electron beam curing station, 32: Film passing device, 33: Electron acceleration chamber, 35: Winding roll, 36: Power supply, 37:
Beam control device, 38: electron beam element,
39: Extension arm, 40: Electronic curtain, 41:
Window, 45: Mold, 49, 51: Press platen,
52-54: Net board, 55: Craft sheet, 5
6: Lamination creation layer, 57-60: Release sheet structure,
61: Resin material.

Claims (1)

[Scope of Claims] 1. A first thin layer of a surface-treated polyester, nylon, or acetylcellulose film, and a cured resin having a patterned surface on one side of the film. A molded release sheet structure for use in a laminate molding operation, comprising: 2. The molded release sheet structure according to claim 1, which has a second thin layer made of the same resin on the other side of the film. 3. The molded release sheet structure of claim 1, wherein the first thin layer is an acrylic resin layer that is peelable from the epoxy resin laminate and curable with an electron beam. 4. The molded release sheet structure according to claim 1, wherein the film is a polyester film made of polyethylene terephthalate. 5. The nylon film comprises a thermostabilized type 66 nylon resin.
Molded release sheet structure as described in Section. 6. A method for producing a molded release sheet structure, comprising: (1) at least one surface of a polyester, nylon or acetyl cellulose film;
treating the surface to improve its ability to accept and retain a resin coating; (2) coating the treated surface with a thin layer of a resin coating; and (3) curing the coating. Method. 7. The method of claim 6, wherein the thin resin layer is easily peelable from both the unclad and clad sides of the epoxy laminate. 8. The method of claim 6, wherein both sides of the film are treated, coated and cured. 9. The method of claim 6, wherein one side of the film is first treated to increase coating material receptivity and then the other side is similarly treated before coating. 10. The method of claim 6, wherein the applied coating is textured. 11. Claim 6, wherein the surface treatment is performed by corona discharge on both sides of the sheet.
The method described in section. 12. The method of claim 6, wherein curing is initiated by electron beam energy. 13 Molded release sheet structures and other laminates for use in laminate forming operations such as the formation of multilayer laminates of circuit boards and other epoxy resin laminates, which are thermally and dimensionally stable; a sheet of smooth, high tensile strength, coatable plastic support layer, the sheet having at least one surface treated to be receptive to a liquid resin coating material; a thin layer of said resin coating material applied to and cured on and to said surface; said resin laminated with a release sheet coated with a clad or unclad epoxy resin laminate; A laminate of a type that can be easily peeled off from an epoxy resin laminate when used. 14. The laminate of claim 13, wherein the sheet of plastic support layer is selected from the group consisting of polyester, nylon, and acetyl cellulose films. 15. The laminate according to claim 13, wherein the resin is of a type that can be cured by electron beam irradiation, and is cured by such irradiation. 16. The laminate according to claim 13, wherein the release sheet has a larger area than the laminate.