JP2004247721A - Method and apparatus for manufacturing electronic circuit board - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method and an apparatus for manufacturing a high-precision electronic circuit board which can peel a flexible sheet forming a flexible electronic circuit board from a reinforcing plate in low stress, even if electronic parts are mounted. <P>SOLUTION: A peeling member is inserted between a reinforcing plate of an electronic circuit board member and the flexible sheet in which an electronic circuit pattern is formed on the reverse surface to the sticking surface of the flexible sheet stuck on one side of the reinforcing plate. The flexible sheet is peeled from the reinforcing plate. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

  The present invention relates to a method and an apparatus for manufacturing an electronic circuit board.

  There are various methods for manufacturing an electronic circuit board, and one of the methods for manufacturing a so-called flexible electronic circuit board, which is frequently used for various electronic products, is to use one side of a rigid reinforcing plate such as a glass plate. After attaching a flexible sheet that forms a flexible electronic circuit board made of a thin sheet of polyimide or the like, and forming an electronic circuit pattern on the surface of the flexible sheet opposite to the attachment surface, a reinforcing plate There is a method of peeling a flexible sheet from a sheet (see Patent Document 1). The flexible sheet may be peeled off after mounting the electronic component. In such a method, it is important to peel the flexible sheet so that stress is not applied as much as possible. When a stress is applied to the flexible sheet at the time of peeling, the electronic circuit pattern formed on the surface is distorted, and the precision of the pattern is reduced. In addition, when the electronic component is mounted, an abnormality may occur in the connection state of the electronic component, and when the electronic component is severe, the electronic component may fall off. In particular, in the case where a fine electronic circuit pattern is formed, it is required to suppress distortion in the order of μm.

By the way, in the field of electronic circuit boards, peeling of a flexible film attached to a rigid substrate is performed on a printed wiring board such as a copper-clad laminate, for example. This is because in such a printed wiring board, a protective film may be attached to the surface for protection during storage or transportation, and it is necessary to peel off the protective film during use. This peeling is performed, for example, by attaching an adhesive tape to one corner of the protective film, lifting the adhesive tape to partially peel off the protective film, and then pulling the protective film diagonally (for example, see Patent Document 1). 2). However, although this method depends on the bonding strength of the protective film, a large peeling stress is applied to the protective film at the time of peeling, so it is difficult to apply the method to the peeling of the flexible sheet in the above-described method.
JP 2003-101193 A JP-A-5-319675

  The present invention has been made in view of the above-mentioned demands of the related art, and an object of the present invention is to enable a flexible sheet forming a flexible electronic circuit board to be peeled from a reinforcing plate with low stress. Provided is a method and an apparatus capable of obtaining a high-precision electronic circuit board even when is mounted.

That is, the present invention has the following configurations.
(1) Between the reinforcing sheet and the flexible sheet of the electronic circuit board member having an electronic circuit pattern formed on the surface opposite to the attaching surface of the flexible sheet attached to one surface of the reinforcing plate A method for manufacturing an electronic circuit board, comprising: inserting a peeling member through a flexible sheet; and peeling the flexible sheet from the reinforcing plate.
(2) The method for manufacturing an electronic circuit board according to the above (1), wherein the peeling member has a wedge shape.
(3) The method for manufacturing an electronic circuit board according to the above (1), wherein a glass plate is used as a reinforcing plate.
(4) The method for manufacturing an electronic circuit board according to (1), wherein the flexible sheet is peeled after mounting the electronic component.
(5) The method for manufacturing an electronic circuit board according to (1), wherein the electronic circuit board member is heated at the time of peeling.
(6) holding means for holding an electronic circuit board member having an electronic circuit pattern formed on a surface of the flexible sheet affixed to one surface of the reinforcing plate opposite to the affixing surface; An apparatus for manufacturing an electronic circuit board, comprising: a flexible sheet peeling means; and a moving means for relatively moving the holding means and the peeling means.
(7) The apparatus for manufacturing an electronic circuit board according to (6), wherein the peeling member has a wedge shape.
(8) The apparatus for manufacturing an electronic circuit board according to (6), wherein the holding unit includes a heating unit for the electronic circuit board member.
(9) The apparatus for manufacturing an electronic circuit board according to (6), wherein the peeling means includes a positioning mechanism for the peeling member.
(10) The apparatus for manufacturing an electronic circuit board according to (6), wherein the peeling member is a single-edged wedge.
(11) An electronic circuit board manufactured by the method according to any one of (1) to (5) or the device according to any one of (6) to (10).

  According to the present invention, by attaching a flexible sheet to a reinforcing plate via a bonding agent layer and maintaining dimensional accuracy, a high-precision circuit pattern is formed, or further, an electronic component is formed into a circuit pattern. After bonding, the flexible sheet forming the flexible electronic circuit board can be peeled from the reinforcing plate with low stress without damage, and even when electronic components are mounted, a high-precision electronic circuit board can be used. Can be obtained.

  In the above, the reinforcing plate is for maintaining the form of the flexible sheet adhered thereon, has rigidity, does not easily plastically deform, and has a small dimensional change due to heat and moisture absorption. For example, a glass plate made of borosilicate glass or the like, a ceramic plate made of alumina or the like, or a glass fiber reinforced resin plate having excellent surface smoothness can be used. Especially, it is preferable to use a relatively inexpensive glass plate. The thickness is about 0.3 to 1.1 mm, depending on the material and the like.

  A flexible sheet forming a flexible electronic circuit board is attached on the reinforcing plate. The flexible sheet is made of, for example, a synthetic resin sheet such as a polyethylene terephthalate sheet, a polyphenylene sulfide sheet, and a polyimide sheet having a thickness of about 4 to 125 μm. Among them, it is preferable to use a polyimide sheet which is excellent in heat resistance and chemical resistance.

  For attaching the flexible sheet to the reinforcing plate, an adhesive or pressure-sensitive adhesive generally called a re-peeling agent such as an acrylic, urethane, or silicone can be used. These adhesives and pressure-sensitive adhesives are preferably interposed between the reinforcing plate and the flexible sheet as a layer having a uniform thickness. If the thickness of the so-called bonding agent layer is too small, it becomes difficult to insert the peeling member. If the thickness is too large, the flexible sheet may be distorted by heat when mounting the electronic component. The thickness is preferably about 5 to 5 μm. Note that these adhesives and pressure-sensitive adhesives are usually applied onto a reinforcing plate using an application device such as a spin coater, a roll coater, or a die coater.

  It is preferable that the bonding agent is weakly adhesive because the flexible sheet can be easily peeled off. As a specific peeling force, the 180 ° peel strength at the time of peeling a 1 cm wide flexible sheet bonded to a reinforcing plate via a bonding layer is from 0.098 N / m to 98 N.m. It is preferably in the range of m. However, the peeling speed when measuring the peeling force is 300 mm / min.

  The formation of the electronic circuit pattern on the flexible sheet can be performed by, for example, a well-known printing method. In addition, a subtractive method using a photoresist, a semi-additive method, or a full-additive method can be used.

  A peeling member to be described later is used for peeling and separating the flexible sheet from the reinforcing plate. Thereby, the flexible sheet can be peeled off without applying a large stress thereto. When the electronic circuit board member is heated at the time of peeling, the adhesive force between the reinforcing plate and the flexible sheet is reduced, and the peeling can be performed with lower stress. Note that the peeling of the flexible sheet from the reinforcing plate can be performed before mounting electronic components, for example, an IC chip, a resistor, and a capacitor, but while the flexible sheet is supported by the reinforcing plate. Is easier to implement, and can be implemented with higher precision. Therefore, it is preferable to peel off after mounting. In addition, the flexible sheet after peeling can be washed as needed, for example, when an adhesive or a pressure-sensitive adhesive remains on the flexible sheet after peeling. For cleaning, an organic solvent, a neutral water-soluble cleaning liquid, or the like can be used.

  The present invention also provides an electronic circuit board member having an electronic circuit pattern formed on a surface opposite to a bonding surface of a flexible sheet bonded to one surface of a reinforcing plate. An electronic circuit board, comprising: a holding means to be held; a peeling means for a flexible film having a peeling member; and a moving means for relatively moving the holding means and the peeling means. Provide a manufacturing device.

  In the above, the holding means correctly holds the electronic circuit board member having the electronic circuit pattern formed on the surface opposite to the sticking surface of the flexible sheet attached to one surface of the reinforcing plate at a predetermined position. For example, it has a mounting table made of a perforated plate or the like connected to a reduced pressure source. The electronic circuit board member is mounted on the mounting table, and is suction-held on the mounting table by the suction action of the reduced pressure source.

  Preferably, the holding means further comprises heating means for the electronic circuit board member. The heating means may be built in, for example, the mounting table of the holding means, or may be provided with, for example, an infrared lamp, a hot air blower, or the like, facing the mounting table.

  The peeling means preferably includes a positioning mechanism for the peeling member. Accordingly, the peeling member can be correctly aligned with a predetermined portion of the electronic circuit board member, and the flexible sheet can be peeled with higher precision. Such a positioning mechanism can be configured, for example, as an adjusting screw mechanism.

  As the peeling member of the present invention, a shape such as a wedge shape, a thin plate shape, or a wire shape can be adopted, and all of them have a thickness enough to be inserted between the reinforcing plate and the flexible sheet and a rigidity capable of progressing the peeling. When the flexible sheet on which the electronic circuit is formed is peeled off from the reinforcing plate by the insertion of the peeling member, if the peeling angle defined by the angle between the flexible sheet and the reinforcing plate at the peeling point increases, Sheet is curled or broken. The shape and thickness of the peeling member are selected, and the peel angle is preferably 80 ° or less, more preferably 70 ° or less.

  The wedge-shaped peeling member is made of tool steel or the like having excellent machinability. Preferably it is a single-edged wedge. A double-edge wedge may be used, but since the peel angle of the double-edge wedge when peeling the flexible sheet is larger than that of a single-edge wedge, the flexible sheet is likely to be distorted accordingly. When the blade angle is too large, the flexible sheet curls or breaks when it is remarkable, and when it is too small, the mechanical strength cannot be maintained, so that it is 5 to 30 °, preferably 5 to 30 °. It is better to be within the range of 20 °. The wedge is preferably used with a slight inclination so that the cutting edge is directed toward the insertion surface in order to reduce the apparent cutting edge angle.

  The thickness of the thin plate-shaped peeling member is preferably 100 μm or less so that the flexible sheet that can be inserted between the reinforcing plate and the flexible sheet and is not greatly bent at the time of peeling. , 50 μm or less. On the other hand, in order to secure rigidity enough to be inserted between the reinforcing plate and the flexible sheet, it is preferable that the thickness of the thin plate type peeling member is 4 μm or more. A strip-shaped metal or resin can be adopted as the thin plate-shaped peeling member. It is preferable to use a material having high rigidity so as to withstand the stress caused by the progress of peeling. For metal, tool steel can be suitably used, and for resin, aramid film or liquid crystal polymer film can be suitably used. In order to maintain the shape, it is preferable to apply tension in the length direction of the thin plate-shaped peeling member. As a method of applying the tension, there are a method of gripping and pulling both ends of the strip-shaped peeling member, and a method of connecting both ends of the strip-shaped peeling member to form a loop and apply tension between two or more support points. If the wedge-shaped peeling member is too thin and lacks self-retention, the tension may be applied in the length direction or the belt-shaped peeling member may be looped to provide tension between two or more support points. Is preferably added. One mode of using a strip-shaped peeling member as a ring will be described with reference to FIGS. The strip-shaped stripping members 8 are joined together at their ends to form a ring. The wheel is tensioned and passed between the drive rolls 9 and 10 and driven in the direction of arrow A. The drive roll holding mechanism or the electronic circuit board member holding means (not shown) is moved up and down so that the peeling member 8 is inserted between the reinforcing plate and the flexible sheet, and the peeling member 8 and the electronic circuit board member are positioned. At the same time, the electronic circuit board member is brought into contact with the peeling member from the direction of arrow B, and the flexible sheet is gradually peeled from the end.

  When a peeling member is used as a loop, rotate the wheel between two or more rolls in order to extend the life of the peeling member evenly in the length direction of the loop to extend the life and to easily apply tension. Preferably. Further, the peeling is advanced while rotating the ring, and polishing the widthwise end of the belt forming the ring extends the life of the peeling member. In addition, the peeled flexible sheet curls, breaks, and sags. Is not preferred. In order to use the belt evenly in the length direction without processing it into a ring, it is preferable to peel off the belt while reciprocating in the length direction of the band.

  The thickness of the wire-shaped peeling member is set so that the flexible sheet can be inserted between the reinforcing plate and the flexible sheet, and the flexible sheet to be peeled is not largely bent (peeling angle is large) at the time of peeling. It is preferably 100 μm or less, more preferably 50 μm or less. A metal wire or a resin wire can be adopted as the wire-shaped peeling member. It is preferable to apply tension in the length direction of the wire-shaped peeling member in order to maintain the shape, similarly to the thin plate-shaped peeling member.

  Among the above peeling members, a wedge-shaped peeling member is excellent in that the peeling is easily started.

  The moving means for relatively moving the holding means and the peeling means can be based on moving the peeling means, but usually, the peeling means is fixed and the holding means is moved. For example, it can be configured as having a base and a rail laid on the base. The mounting table described above is mounted on the rail. The mounting table is moved forward and backward on the rail by a ball screw mechanism by a servomotor, for example.

  FIGS. 1, 2 and 3 show an apparatus for manufacturing an electronic circuit board according to one embodiment of the present invention. In FIG. 1, the apparatus has a base 2 on which a rail 1 is laid on the upper surface. A mounting table 3 is mounted on the rail 1. The mounting table 3 is connected to a ball screw (not shown) driven by a servomotor, and can reciprocate on the rail 1 in the left-right direction in the drawing by driving the servomotor.

  A frame 7 is mounted on the base 2, and a plurality of free rolls 4, 4,... Are mounted on the frame 7 side by side at a constant height in the horizontal direction in the drawing.

  Above the rail 1, a peeling means 5 is provided so as to be movable up and down. The peeling means 5 has a height adjusting mechanism 5a such as an adjusting screw mechanism, a cradle 5b connected to the height adjusting mechanism 5a, and a wedge 5c mounted on the cradle 5b. The height adjusting means 5a adjusts the height of the cutting edge of the wedge 5c, so that when the peeling means 5 is lowered, the cutting edge 5c can be connected to the bonding agent layer 6b of the electronic circuit board member 6 described later. It becomes possible to correctly match the interface with the flexible sheet 6c. Further, as shown in FIG. 2, the peeling means 5 is configured as a double-sided structure so that the flexible sheet peeled from the reinforcing plate can pass between the cradle 5b and 5b as described later. It has become.

  In the apparatus of this embodiment, first, as shown in FIG. 1, the electronic circuit board member 6 is mounted on the mounting table 3 and fixed. The electronic circuit board member 6 has a reinforcing plate 6a and an electronic circuit pattern formed on a surface of the reinforcing plate 6a that is attached to the reinforcing plate 6a via a bonding agent layer 6b and that is opposite to a surface attached to the reinforcing plate 6a. And a flexible sheet 6c.

  Next, the peeling means 5 is lowered, and the mounting table 3 is moved on the rail 1 at a constant speed in the direction of the arrow (rightward in the drawing). When the mounting table 3 moves, the wedge 5c of the peeling means 5 is inserted into the interface between the bonding agent layer 6b of the electronic circuit board member 6 and the flexible sheet 6c as shown in FIG. Then, the flexible sheet 6c is separated from the bonding agent layer 6b. That is, the flexible sheet 6c is peeled and separated from the reinforcing plate 6a. Even when the wedge 5c is laid through the interface between the reinforcing plate 6a and the bonding agent layer 6b or in the bonding agent layer 6b, the peeling force between the bonding agent layer and the flexible sheet is determined by the peeling force between the reinforcing plate and the bonding agent layer. By making it sufficiently smaller than the internal destruction of the bonding agent layer, the separation proceeds by several mm to several cm and the separation interface naturally moves to the interface between the bonding agent layer 6b and the flexible sheet 6c.

  The flexible sheet 6c to be peeled passes through between the cradle 5b and the cradle 5b of the peeling member 5 shown in FIG. 2 with further movement of the mounting table 3, and becomes free as shown by a two-dot chain line in FIG. Are placed on the rolls 4, 4,... And transported to the next step by a transfer means (not shown).

  Next, the peeling means 5 is raised to the position before the lowering, and the mounting table 3 is moved back to the left in the drawing. When the mounting table 3 is returned to the original position, the transfer means (not shown) removes the electronic circuit board member from the mounting table 3 after the flexible sheet 6c has been peeled off and separated, and a new electronic device is mounted. The circuit board member is placed on the placing table 3. Thereafter, electronic circuit boards are manufactured one after another by repeating the same operation.

  In the above description, the moving speed of the mounting table depends on the type of the adhesive or the pressure-sensitive adhesive forming the bonding agent layer of the electronic circuit board member, that is, the bonding force or the wedge edge angle, but is too fast. In some cases, the release sheet may become uneven or wrinkles may be formed on the flexible sheet to be peeled off, and if it is too slow, the production efficiency deteriorates.

  FIG. 4 is an explanatory view of another embodiment of the peeling means 5 of the present invention. A cradle 5b is provided with a thin stripping member 5d. The end of the thin plate-shaped peeling member 5d is fixed by a gripping means 5e provided on the cradle 5b, and tension is applied in the length direction. When using a thin plate-shaped peeling member, the peeling start position of the reinforcing plate and the flexible sheet may be peeled off by about several mm in advance by another means. This is preferable in that it allows layers to pass between them. If it is about several mm from the peeling start position, it can be out of the effective area of the electronic circuit board, so that the quality after peeling near the peeling start position can be tolerated. Also, the same effect can be obtained by not providing a bonding agent layer between the flexible sheet and the reinforcing plate about several mm in the vicinity of the peeling start position, and making the flexible sheet protrude a few mm from the reinforcing plate. preferable.

Example 1
As a reinforcing plate, an aluminoborosilicate glass plate having a thickness of 1.1 mm and a square of 300 mm, and as a flexible sheet, a polyimide sheet having a thickness of 25 μm and a square of 290 mm (“Kapton” 100EN manufactured by Toray Dupont Co., Ltd.) Each was prepared.

  Next, using a die coater, an ultraviolet-curable acrylic pressure-sensitive adhesive (“SK Dyne” SW-22 manufactured by Soken Chemical Co., Ltd.) and a hardening agent L45 manufactured by Soken Chemical Co., Ltd. were used in a weight ratio of 50: The mixture was adjusted to 1 and dried at 80 ° C. for 2 minutes. The thickness of the pressure-sensitive adhesive layer (bonding agent layer) after drying was 2 μm. Next, the polyimide sheet was attached on the adhesive layer using a roll laminator, and the adhesive was cured by irradiating ultraviolet rays from the glass plate side. Next, a chromium / nickel alloy film having a thickness of 5 nm and a copper film having a thickness of 200 nm were formed in this order on the polyimide sheet by sputtering. Next, a positive type photoresist was applied on the copper film using a spin coater, and dried at 80 ° C. for 10 minutes to form a photoresist layer. The thickness of the photoresist layer was 10 μm. Next, the photoresist layer was exposed through a photomask and developed.

  Next, after post-baking at 120 ° C. for 10 minutes, a copper layer having a thickness of 5 μm was formed by electrolytic plating using the copper film as an electrode. Next, the photoresist layer is stripped with a stripping solution, the copper film and the chromium-nickel alloy film under the photoresist layer are removed by soft etching with a hydrogen peroxide / sulfuric acid-based aqueous solution, and further, using an electroless plating method. A tin layer having a thickness of 0.4 μm was formed on the copper film to obtain an electronic circuit pattern. Next, using a flip chip bonder, a model IC chip was mounted on the electronic circuit pattern to form an electronic circuit board member.

  Next, using the apparatus shown in FIGS. 1 to 3, a single-edge wedge is inserted between the polyimide sheet and the adhesive layer by the method described with reference to FIGS. 1 to 3, and the polyimide sheet is gradually removed from the glass plate. Was peeled off. The edge angle of the wedge of one edge was 10 °, and the moving speed of the mounting table was 300 mm / min. No curl was observed in the obtained polyimide sheet, that is, in the flexible electronic circuit board. Also, the polyimide sheet could be easily peeled off at the mounting portion of the model IC chip, and no break or deformation occurred in the circuit pattern.

Example 2:
In Example 1, prior to peeling, the electronic circuit board member on the mounting table was heated to 150 ° C. using an infrared lamp. The resistance at the time of peeling was smaller than that of Example 1, and no adhesive remained on the peeled surface of the polyimide sheet. Also, the polyimide sheet could be easily peeled off at the mounting portion of the model IC chip, no curl was observed after peeling, and no break or deformation occurred in the circuit pattern.

Example 3
When applying the bonding agent layer to the glass substrate, the same as in Example 1 except that the application area was 290 mm × 285 mm and one side of the 290 mm square polyimide film was protruded by 5 mm from the bonding agent layer. A circuit pattern was obtained, and a model IC was mounted on the electronic circuit pattern to form an electronic circuit board member.

  The wedge-shaped peeling member of the peeling means 5 of the peeling device shown in FIG. 1 was replaced with the thin plate-shaped peeling member shown in FIG. The thin strip-shaped release member was made of a polyamide film having a thickness of 8 μm (“ALAMICA” manufactured by Toray Industries, Inc.) with a width of 30 mm, and was held under tension between credols 5b. Insert a thin stripping member between the polyimide film and the glass plate where one side of the polyimide film protrudes from the bonding agent layer, and move the mounting table at 300 mm / min to separate the polyimide film from the glass plate did.

  No curl was observed in the obtained polyimide sheet, that is, in the flexible electronic circuit board. Also, the polyimide sheet could be easily peeled off at the mounting portion of the model IC chip, and no break or deformation occurred in the circuit pattern.

Comparative example:
From the electronic circuit board member in Example 1, the end of the polyimide sheet was grasped by hand, and was gradually lifted to separate the polyimide sheet from the glass plate.

  The peeling force was increased in the portion where the model IC chip was mounted, and a part of the circuit pattern on the polyimide sheet was broken.

FIG. 1 is a schematic front view showing an electronic circuit board manufacturing apparatus according to one embodiment of the present invention. FIG. 2 is a schematic perspective view of a main part of a peeling unit in FIG. FIG. 2 is a schematic front view of the manufacturing apparatus showing the movement of the electronic circuit board manufacturing apparatus shown in FIG. 1. FIG. 4 is a schematic view showing another embodiment of the peeling means of the present invention. FIG. 4 is a schematic view showing another embodiment of the peeling means of the present invention.

Explanation of reference numerals

1: rail 2: base 3: mounting table 4: free roll 5: peeling means
5a: Height adjustment mechanism
5b: Cradle
5c: wedge-shaped peeling member
5d: thin plate type peeling member
5e: Thin plate-type peeling member gripping means 6: Electronic circuit board member
6a: reinforcing plate
6b: bonding agent layer
6c: flexible sheet 7: frame 8: thin strip-shaped release member 9, 10: drive roll

Claims (11)

A peeling member between a reinforcing plate and a flexible sheet of an electronic circuit board member having an electronic circuit pattern formed on a surface opposite to a bonding surface of a flexible sheet attached to one surface of a reinforcing plate. And peeling the flexible sheet from the reinforcing plate. The method for manufacturing an electronic circuit board according to claim 1, wherein the peeling member has a wedge shape. The method for manufacturing an electronic circuit board according to claim 1, wherein a glass plate is used as the reinforcing plate. The method for manufacturing an electronic circuit board according to claim 1, wherein the flexible sheet is peeled after mounting the electronic component. The method for manufacturing an electronic circuit board according to claim 1, wherein the electronic circuit board member is heated at the time of peeling. Holding means for holding an electronic circuit board member formed by forming an electronic circuit pattern on a surface opposite to the sticking surface of the flexible sheet attached to one surface of the reinforcing plate; and a peeling member. An apparatus for manufacturing an electronic circuit board, comprising: a flexible sheet peeling unit; and a moving unit that relatively moves the holding unit and the peeling unit. The apparatus for manufacturing an electronic circuit board according to claim 6, wherein the peeling member has a wedge shape. 7. The apparatus for manufacturing an electronic circuit board according to claim 6, wherein the holding means includes a heating means for the electronic circuit board member. The apparatus for manufacturing an electronic circuit board according to claim 6, wherein the peeling means includes a positioning mechanism for the peeling member. The apparatus for manufacturing an electronic circuit board according to claim 6, wherein the peeling member is a single-edge wedge. An electronic circuit board manufactured by the method according to any one of claims 1 to 5 or the apparatus according to any one of claims 6 to 10.

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