JP5021985B2 - Method for producing double-sided copper-clad laminate - Google Patents

Description

The present invention relates to a method for producing a double-sided copper-clad laminate in which insulation on both sides is ensured.

  In recent years, printed wiring boards have been made thinner in order to cope with applications of small electronic devices such as mobile phones. For example, in a double-sided copper-clad laminate that forms a printed wiring board, copper foil is disposed on both sides of the plate-like insulating resin layer. However, it is necessary to reduce the thickness, and recently, a laminate having a thickness of 100 μm or less has been used.

  Along with such a reduction in the thickness of the laminated board, there is a concern that a very small amount of foreign matter may be mixed during the production of the laminated board, which may cause conduction on both sides. For example, when a metal foreign matter having a size of about 30 μm is mixed in the surface of a double-sided copper-clad laminate, if the plate thickness is about 800 μm, it does not affect the insulation in the thickness direction (Z direction), but about 40 μm If it is a plate | board thickness, the thickness of a real insulating layer will be about 10 micrometers, and insulation will be worried.

  As described above, with the thinning of copper-clad laminates, there is a growing concern that the entry of extremely small foreign objects, which has not been a problem in the past, will cause double-sided conduction. When used as a wiring board, its performance and reliability are greatly impaired.

  Therefore, first of all, along with the thinning of the copper-clad laminate, it is necessary to check the presence / absence of double-sided conductivity as described above to improve the reliability of the product. As a method for this, there is a test method for confirming that conduction is not caused by applying a voltage to both surfaces of a copper-clad laminate.

  Various studies have been made on such a continuity test method. For example, when conducting a continuity test, by inserting a large resistor in series and monitoring a minute current, a method for evaluating the reliability of an electronic component can detect a defect without causing an excessive current to flow when a printed circuit board short circuit occurs. (Patent Document 1) and the like have been developed.

  However, in the method of confirming continuity by applying a voltage to both sides of the laminated board, the copper foil part is more easily contacted with the end face of the laminated board as the thickness is reduced to 100 μm or less, for example. There was a problem that became difficult.

For this reason, there is a demand for a measure for easily and accurately performing the above continuity test even in a thinned copper-clad laminate.
JP 2000-304801 A

  Accordingly, the present invention provides a new technical means capable of easily and accurately conducting a continuity test by applying a voltage to both sides of a thinned copper-clad laminate from the background as described above. Is an issue.

In order to solve the above problems, a method for producing a double-sided copper-clad laminate of the present invention is a method for producing a double-sided copper-clad laminate in which at least a pair of copper foils are disposed and integrated via a resin layer, When the copper foil is disposed on both surfaces of a prepreg layer obtained by impregnating and drying an epoxy resin composition on a predetermined number of glass cloths to form the resin layer, at least one side of the copper foil and the prepreg layer After sandwiching a release sheet obtained from a fluororesin composition or a polypropylene resin composition with the outer shape being substantially the same as the prepreg layer so as to cover the outer periphery of the copper foil, Removing the copper foil portion on the release sheet and the release sheet and removing the copper foil portion as a whole outer peripheral portion, thereby attaching the copper foil to at least one of the copper foils to the resin layer. The surface of the resin layer Molded as well on the inside of the outer periphery, the copper foil of the double-sided is characterized in that to prevent conduction.

  First, the double-sided copper-clad laminate of the present invention is a double-sided copper-clad laminate in which at least a pair of copper foils are disposed and integrated via a resin layer, and at least one copper of the pair of copper foils The sticking surface to the resin layer of foil is inside the outer periphery of the resin layer.

  2ndly, the manufacturing method of the double-sided copper clad laminated board of this invention is a manufacturing method of the double-sided copper clad laminated board which arrange | positions and integrates at least a pair of copper foil through a resin layer, Comprising: At least one of the copper foils is bonded to the resin layer so that the surface of the copper foil is inside the outer peripheral edge of the resin layer so that the copper foils on both sides do not conduct.

  Third, in the second manufacturing method, when the copper foil is disposed on both surfaces of the predetermined number of prepreg layers forming the resin layer, the copper foil is at least between the copper foil on one side and the prepreg layer. The release sheet is sandwiched so as to cover the outer peripheral portion of the sheet, and after heating and pressing, the release sheet and the copper foil portion on the release sheet are removed.

  Fourth, in the second manufacturing method, when the copper foil is disposed on both surfaces of the predetermined number of prepreg layers forming the resin layer, at least on the outer peripheral portion of the bonding surface to the prepreg layer of the copper foil on one side After performing a mold release process and heat-press molding, the outer peripheral part of the copper foil subjected to the mold release process is removed.

  Fifth, in the manufacturing method of the second invention, after placing copper foil on both sides of a predetermined number of prepreg layers forming the resin layer and heat-press molding, at least one outer peripheral portion of the copper foil is laser Remove with.

  Sixth, when the copper foil is disposed on both sides of the predetermined number of prepreg layers forming the resin layer in the second manufacturing method, at least one side of the copper foil attached to the prepreg layer is a prepreg layer. A release sheet is further arranged on the surface opposite to the surface of the copper foil attached to the prepreg layer, heat-pressed, and then the release sheet is removed.

  Seventhly, in the second manufacturing method, a copper foil in which an adhesive is applied to the surface to be bonded to the resin surface is affixed inside the outer peripheral edge of the resin surface on the resin surface side of the single-sided copper-clad laminate.

  Eighth, in the second manufacturing method, copper foil is disposed on both sides of a predetermined number of prepreg layers forming the resin layer, and after heat-press molding, at least one outer peripheral portion of the copper foil is etched. To prevent the copper foils on both sides from conducting.

  Ninth, in the second manufacturing method, when the copper foil is disposed on both sides of the predetermined number of prepreg layers forming the resin layer, the bonding surface of at least one copper foil of the pair of copper foils to the resin layer Is placed on the inner side of the outer peripheral edge on the copper foil sticking surface of a predetermined number of prepreg layers, and is heated and pressed using a press machine in which the surface of the hot plate is coated with Teflon (registered trademark).

  Tenth, in the second manufacturing method, a copper foil is disposed on both sides of a predetermined number of prepreg layers for forming a resin layer, and heat-press molding is performed, and then the outer peripheral portion of at least one side of the copper foil is polished. Polish and remove.

  Eleventhly, in the second manufacturing method, a release sheet is disposed in the center, and on both sides thereof, a copper foil having a surface attached to the prepreg layer on the inner side of the outer peripheral edge of the prepreg layer, a predetermined number of prepregs A copper foil in which the outer peripheral edge of the surface to be applied to the layer and the prepreg layer is outside the outer peripheral edge of the prepreg layer is disposed in order, and is heated and pressed.

According to the present invention, an insulating band is formed on the outer peripheral portion of the formed copper foil arrangement portion. For example, even in a thin double-sided copper-clad laminate having a thickness of 100 μm or less, It is possible to prevent contact, and it is possible to easily and accurately conduct a continuity test by applying a voltage to both surfaces. As a result, the quality reliability of the laminated product can be secured and enhanced.
And the insulation band of a predetermined width is formed in the predetermined position of the outer peripheral part of the formed copper foil arrangement | positioning part, and can insulate both surfaces of a double-sided copper clad laminated board reliably. That is, a release sheet is sandwiched so as to cover the outer peripheral portion of the adhesive surface of the copper foil to the prepreg layer, and after heat and pressure molding, the release sheet and the copper foil portion on the release sheet are removed to obtain a predetermined An insulating band having a predetermined width can be reliably formed at the position.

  In the double-sided copper-clad laminate of the present invention, as described above, at least a pair of copper foils are disposed and integrated via the resin layer, and at least the bonding surface of the copper foil on one side to the resin layer is It is inside the outer peripheral edge of the resin tank. Such a laminate may have a multilayer configuration. The resin layer may be formed with a prepreg, or may be formed with a resin film, sheet, nonwoven fabric, or the like. In any case, copper foil is disposed on both surfaces of the outermost layer, and the pair of copper foils has a surface of at least one of the copper foils attached to the resin layer inside the outer peripheral edge of the resin layer. Therefore, they are prevented from conducting each other. That is, in the double-sided copper-clad laminate of the present invention, even if the resin layer is thin and the copper foils on both sides approach each other, they never come into contact.

  The “predetermined number” is usually about 2 to 6, for example, although it varies depending on the application and configuration. Here, the “prepreg” is obtained by impregnating a base material that can be impregnated with a resin composition such as a glass woven fabric with a thermosetting resin such as an epoxy resin, or by semi-curing (B-stage) it. .

  An insulating band having no copper foil is formed in the vicinity of the outer peripheral edge of at least one surface. The “insulating band” is formed in a band shape along the outer peripheral portion of the resin layer, and electrically isolates the central portion and the outer peripheral portion of the copper foil arrangement portion. In order to effectively use the copper foil arrangement portion, it is preferable that the outermost peripheral side of the insulating band and the outer peripheral edge of the resin layer are made to coincide with each other. However, even if a slight copper foil layer remains along the outer peripheral edge of the resin layer, it is sufficient that an insulating band is formed on the inner side. The width of the insulating band can be appropriately set according to the use of the double-sided copper-clad laminate, but is preferably in the range of 1 to 5 mm. There are various methods for forming the insulating band in the present invention, but in the present invention, it is desirable to adopt a new manufacturing method as described above. In the production method of the present invention, the thickness of the double-sided copper-clad laminate when using the prepreg is not particularly limited, and may be 100 μm or less, and usually about 30 to 80 μm is considered. The The copper foil is integrally formed on the copper foil sticking surface of the resin layer by heat and pressure molding. The “copper foil placement portion” is a portion where the copper foil is placed on the copper foil sticking surface of the resin layer by this integral molding.

  Examples of the production method of the present invention are as follows.

  In any of the following forms, a double-sided copper-clad laminate capable of easily and accurately conducting a continuity test by applying a voltage to both sides even when the thickness is reduced can be obtained.

That is, it is possible to accurately check whether or not there is double-sided conduction due to extremely small foreign matter mixed in the thinned copper-clad laminate without being affected by the contact of the copper foil at the end face. It becomes easy to secure and improve the performance reliability of the thinned copper-clad laminate.
1. A method of forming an insulating band on the outer peripheral edge of one side of a laminated board by a release sheet.

  When the copper foils 1A and 1B are arranged on both surfaces of a predetermined number of the prepreg layers 3, as shown in FIG. 1, at least one side of the copper foil 1A and the prepreg layer 3 have the same shape as the insulating band to be formed. The release sheet 2 is sandwiched and the laminate is heated and pressed to remove the release sheet 2. When this treatment is performed, the copper foil layer formed on the release sheet is also removed. Here, as illustrated in FIG. 1, the release sheet 2 has an outer shape that is substantially the same as that of the prepreg layer 3, for example, and a copper foil having a predetermined size (plane) is disposed on the inner side thereof. It is cut out so that. In the place where the release sheet 2 is disposed, an insulating band having the same shape as the release sheet is formed on the surface of the laminate. As the release sheet used here, a commercially available sheet from a fluorine-based resin composition, a polypropylene resin composition, or the like can be used.

For example, when manufacturing a double-sided copper-clad laminate using a prepreg 3 plate obtained by impregnating and drying an epoxy resin composition in a glass cloth, fluorine having an insulation band width of 3 mm as shown in FIG. When a release sheet 2 from the resin composition is interposed to form a double-sided copper-clad laminate having a thickness of 40 μm, in a continuity test by applying a voltage of 50 V and 100 V to both sides, there is no contact with the copper foil at the end face The test could be performed without being affected. In this continuity test, the presence / absence of continuity due to the inclusion of a very small amount of foreign matter could be simply and accurately implemented.
2. A method in which a mold release treatment is performed in the vicinity of the outer peripheral edge of one surface of the copper foil, and the copper foil is arranged so that the surface subjected to the mold release treatment is in contact with the prepreg layer.

  When the copper foil is disposed on both surfaces of a predetermined number of prepreg layers, a mold release treatment is applied to the vicinity of the outer peripheral edge of the surface of the copper foil on at least one side in contact with the prepreg layer. As the mold release treatment, for example, a fluorine-based mold release agent or the like is exemplified, and it can be applied by spraying or the like. As shown in FIG. 2, a normal copper foil 1, a predetermined number of prepreg layers 3, and a copper foil 4 having been subjected to a release treatment 4 </ b> A are stacked, and then heated and pressed. By performing the process of removing the mold release processing unit 4A, the copper foil part facing the mold release processing unit 4A is also removed. By forming the release treatment part 4A having the same shape as the insulation band formed on one side of the double-sided copper-clad laminate on the copper foil one side in advance, an insulation band of a predetermined shape is formed on one side of the double-sided copper-clad laminate Will be.

  When the fluorine release agent is applied by spraying so that the width of the insulation band is actually 4 mm, the above 1. As in the case of, good effects were obtained.

The same applies to the following methods.
3. The method of removing the outer peripheral part of the copper foil of the single side | surface of a double-sided copper clad laminated board with a laser.

Copper foils are arranged on both sides of a predetermined number of prepreg layers, heated and pressed, and then the copper foil is removed by irradiating at least the outer periphery of the copper foil on one side. By controlling the laser irradiation position so that the insulating band is formed, the insulating band is formed along the laser irradiation position on at least one side of the double-sided copper-clad laminate. The laser used here can be used as long as it can remove the copper foil, such as a carbon dioxide laser or a UV-YAG laser.
4, the surface of the copper foil to the prepreg layer is on the inner side of the outer peripheral edge of the prepreg layer, and a release sheet is further disposed on the surface opposite to the surface of the copper foil to the prepreg layer, A method of heat and pressure molding.

When placing the copper foil on both sides of the predetermined number of prepreg layers, as shown in FIG. 3, at least one side of the copper foil 1A is attached to the prepreg layer 3 on the inner side of the outer peripheral edge of the prepreg layer 3, The release sheet 2 is further installed on the surface opposite to the surface of the copper foil 1A attached to the prepreg layer 3, and after heat-pressing, the release sheet is removed. Thereby, the insulation band without copper foil is formed in the outer peripheral part of the at least single side | surface of a double-sided copper clad laminated board.
5. A method of attaching a copper foil coated with an adhesive to the resin surface on the resin surface side of the single-sided copper-clad laminate inside the outer peripheral edge of the resin surface.

As shown in FIG. 4, the copper foil 1 is bonded to the resin surface of the single-sided copper-clad laminate 5 on which the copper foil is not stretched with an adhesive. The size and position of the copper foil 1 are set so that the surface of the copper foil 1 attached to the resin layer is inside the outer peripheral edge of the resin surface. By carrying out like this, the surface of the laminated board which affixed the copper foil 1 will have the copper foil arrangement | positioning part 7 and the insulating band 8 without copper foil in an outer peripheral part.
6. The method of removing the outer peripheral part of the copper foil of at least one side of a double-sided copper-clad laminate by etching.

As shown in FIG. 5, copper foil is arranged on both surfaces of a predetermined number of prepreg layers, and in the double-sided copper-clad laminate 6 formed by heating and pressing, at least the outer peripheral portion of the copper foil on one side is removed by etching treatment. . As a result, an insulating band 8 having no copper foil is formed on the outer peripheral portion of this surface. Etching is performed by, for example, arranging an etching resist except for the outer peripheral portion to be etched, removing the resist after etching with copper chloride or iron chloride, and removing the double-sided copper-clad laminate from which the outer peripheral copper foil has been removed. The method of making is illustrated.
7. Place the surface of the pair of copper foils to be attached to the prepreg layer of the copper foil on the copper foil application surface of the predetermined number of layers of the prepreg, and place it on the inner side of the outer peripheral edge, followed by heating and pressing. The method of arranging by.

  When placing copper foil on both sides of a predetermined number of prepreg layers, at least one side is placed by hot-press molding a copper foil having a pasting surface inside the outer peripheral edge of the copper foil placement surface of the prepreg layer To do. This hot pressing is performed by applying a Teflon (registered trademark) coating on the surface of the hot plate of the press apparatus. By doing so, the copper foil is not fused to the hot plate and can be molded smoothly. The position where the copper foil is disposed is a position where the side of the copper foil does not contact or intersect the side of the resin layer. Thereby, the insulation band without copper foil is formed in the outer peripheral part of the surface where the small copper foil of a double-sided copper clad laminated board is arrange | positioned.

Further, as shown in FIG. 6, a release sheet 2 is arranged in the center, and on both sides thereof, a copper foil 1 </ b> A having a prepreg layer 3 application surface on the inner side of the outer peripheral edge of the prepreg layer 3, 3. A double-sided copper-clad laminate having an insulating band on one side can be produced by arranging the copper foil 1B in order and then heat-pressing it.
8. A method of removing at least one outer peripheral portion of the copper foil of the double-sided copper-clad laminate by polishing.

  As shown in FIG. 7, after placing copper foils 1A and 1B on both sides of a predetermined number of prepreg layers 3 and heating and press-molding, at least one side of the copper foil disposing portion is polished near the outer periphery. Remove the foil. Thereby, an insulation band is formed along the polishing position on at least one side of the double-sided copper-clad laminate.

It is a perspective view which forms a laminated body by inserting | pinching the release sheet of the same shape as the insulation band to form between the copper foil and prepreg layer of one side. It is a perspective view which laminates | stacks the normal copper foil, the layer of a prepreg, and the copper foil in which the mold release process was performed, and forms a laminated body. Install the release sheet on the surface opposite to the surface of the copper foil prepreg that is attached to the prepreg layer of the copper foil on the inner side of the outermost periphery of the resin layer. It is a perspective view which forms a laminated body. It is a perspective view which affixes copper foil with the adhesive agent inside the outermost periphery of the surface where the copper foil of the single-sided copper clad laminated board is not tensioned, and forms a laminated body. It is a perspective view which removes the outer peripheral part of the copper foil of one side by an etching process. A release sheet is arranged in the center, and on both sides, a copper foil whose surface to be attached to the prepreg layer is inside the outer peripheral edge of the prepreg layer, a predetermined number of prepreg layers, and a copper foil are arranged in order. It is a perspective view which forms. It is sectional drawing which grind | polishes the outer periphery vicinity of the copper foil arrangement | positioning part of one side, and removes copper foil.

Explanation of symbols

1, 1A, 1B Copper foil 2 Release sheet 3 Prepreg layer 4 Copper foil (peripheral part release treatment)
4A Release processing part 5 Single-sided copper-clad laminate 6 Double-sided copper-clad laminate 7 Copper foil placement part 8 Insulation band

Claims (1)

A method for producing a double-sided copper-clad laminate in which at least a pair of copper foils are disposed and integrated via a resin layer, wherein a predetermined number of glass cloths forming the resin layer are impregnated with an epoxy resin composition and dried. When the copper foil is disposed on both surfaces of the prepreg layer obtained in the above, the outer shape of the prepreg layer is so as to cover the outer periphery of the copper foil between the copper foil and the prepreg layer on at least one side. After sandwiching a release sheet obtained from a fluorine resin composition or a polypropylene resin composition that is substantially the same and heat-press molding, the release sheet and the copper foil part on the release sheet are removed to remove the copper foil part. By removing as a whole outer peripheral part, the bonding surface to the resin layer of at least one of the pair of copper foils is shaped to be inside the outer peripheral edge of the resin layer, Copper foil does not conduct Method for producing a double-sided copper-clad laminate which is characterized in that the.

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