JP2013120793A - Wiring board manufacturing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a wiring board manufacturing method capable of resolving inconvenience by aligning a pre-preg and a conductor pattern almost flush with each other.SOLUTION: A support substrate 1 is opposed to a copper foil 2 with thickness of 12 μm or less, and they are adhered by a frame-shaped viscosity layer 4. Peripheral edges of the viscosity layer 4 and the copper foil 2 are made attachable and detachable to constitute an intermediate body. A predetermined electrode pattern 9 is formed on the copper foil 2 of the intermediate body by a semi-additive method, and a pre-preg 10 and a copper foil 11 for lamination are laminate-pressed to the predetermined electrode pattern 9 of the intermediate body to form a predetermined wiring pattern on the copper foil 11 for lamination and constitute a laminate body 12. After the support substrate 1 is removed from the laminate body 12 together with the viscosity layer 4, the copper foil 2 is removed from the pre-preg 10 of the laminate body 12 so as to align the predetermined electrode pattern 9 and the pre-preg 10 flush with each other.

Description

  The present invention relates to a method of manufacturing a wiring board used for a semiconductor package, a mobile phone, a portable information terminal and the like.

  For example, as shown in FIG. 10, the conventional wiring board is formed by alternately laminating and pressing a plurality of copper foils 2A and prepregs 10 so that the uppermost copper foil 2A is formed in a wiring pattern and the lowermost layer. The copper foil 2A is formed on the electrode pattern 9 (see Patent Documents 1, 2, 3, 4, 5, 6, and 7).

  There are various types of copper foil 2A and prepreg 10, but when the wiring board is required to be lighter or thinner, copper foil 2A having a thickness of 18 μm or less is used, and prepreg having a thickness of 100 μm or less. 10 is selected. The electrode pattern 9 is formed by various etching methods, protrudes downward by a thickness from the lower surface of the prepreg 10 to form irregularities, and forms an uneven relationship with the lower surface of the prepreg 10. .

JP 2004-235323 A JP 2006-324541 A JP 2002-76621 A JP 2007-324161 A JP 2000-068648 A JP 2010-153628 A JP 2009-71132 A

  The conventional wiring board is configured as described above, and the prepreg 10 and the electrode pattern 9 are not flush with each other. Therefore, the wiring board is hindered from being thinned, or the wiring board is a surface-mounted semiconductor package ( For example, when it is used as a substrate of BGA, PBGA, FBGA, etc., it may be difficult to mount solder balls.

  The present invention has been made in view of the above, and an object of the present invention is to provide a method of manufacturing a wiring board capable of eliminating the inconvenience by aligning the prepreg and the conductor pattern substantially flush with each other.

In the present invention, in order to solve the above-mentioned problem, it is a method for manufacturing a wiring board for manufacturing a thin wiring board using at least a support base material and copper foil,
The support substrate and a copper foil having a thickness of 12 μm or less are opposed to each other and adhered by a substantially frame-shaped adhesive layer, and the intermediate body is configured by making this adhesive layer and the substantially peripheral edge of the copper foil detachable, A predetermined conductor pattern is formed on the intermediate copper foil by a semi-additive method, and a predetermined wiring pattern is formed on the laminated copper foil by laminating and pressing a prepreg and a laminated copper foil on the intermediate predetermined conductor pattern. After forming the laminated body by removing the support substrate and the adhesive layer from the laminated body, the copper foil is removed from the prepreg of the laminated body so that the predetermined conductor pattern and the prepreg are substantially flush with each other. It is characterized by that.

The carrier base material can be detached from the copper foil after the copper base material is detachably laminated and held on the carrier base material and the substantially frame-shaped adhesive layer is adhered to the substantially peripheral portion of the exposed surface.
Further, the adhesive layer can be detachably adhered to the substantially peripheral portion of either one of the front and back surfaces of the copper foil, and the copper foil can be adhered to the support base material and adhered with the adhesive layer.
In addition, a resist layer is laminated on the copper foil constituting the intermediate and exposed and developed, so that a pattern for a predetermined conductor pattern is patterned on the resist layer, and the intermediate is plated to form a resist layer. A predetermined conductor pattern can also be formed on the pattern.

In addition, by laminating the laminated copper foil on the laminated copper foil of the laminated body via a prepreg and repeating the process of forming a predetermined wiring pattern on this new laminated copper foil, the laminated body is multilayered. It is possible to
Furthermore, after the laminate is divided along the inner peripheral portion of the adhesive layer and the peripheral portion of the laminate is removed together with the adhesive layer, the copper foil is removed from the prepreg of the laminate and the predetermined conductor pattern and the prepreg are substantially omitted. It is also possible to make it flush.

  Here, the copper foil in a claim is adhere | attached on the front and back of a support base material, the surface of a support base material, or the back surface of a support base material. The substantially peripheral portion of the copper foil includes a peripheral portion and its vicinity. The predetermined conductor pattern includes a predetermined wiring pattern, an electrode pattern, and the like. Further, a via for connection is formed between the layers of the laminate, and the via can be plated.

  According to the present invention, since the prepreg is integrated by heating and pressing to the predetermined conductor pattern of the intermediate body, the predetermined conductor pattern and the prepreg are less likely to be uneven, and these can be substantially flush. .

According to the present invention, there is an effect that the inconvenience can be solved by aligning the prepreg and the conductor pattern substantially flush with each other. In addition, since a predetermined conductor pattern is formed on the intermediate copper foil by a semi-additive method, a fine pattern can be formed with high accuracy.
In addition, according to the second aspect of the present invention, since a thin copper foil is adhered to the support base material by the adhesive layer to ensure strength and rigidity, the handling of the difficult-to-handle copper foil is complicated and delayed. There are few things. In addition, since the copper foil is adhered to prevent the occurrence of displacement and wrinkles, the occurrence of wiring unevenness can be suppressed and the reliability and quality of the product can be improved.

According to the invention described in claim 3, since the strength of the laminated body gradually increases due to the multi-layered laminated body, there is little trouble in adhesion and lamination of the copper foil for lamination. Further, if the multilayer body is made multi-layered, it is possible to easily cope with an increase in the amount of wiring, so that it becomes possible to cope with high performance and miniaturization of the LSI, an increase in the number of parts, and the like.
Furthermore, according to the invention described in claim 4, when it is difficult to remove the laminated body due to deterioration of the adhesive layer, or when it is desired to separate the laminated body regardless of the adhesiveness of the adhesive layer, the laminated body is surely removed. It becomes possible.

It is a perspective explanatory view showing typically the copper foil and adhesion layer in the embodiment of the manufacturing method of the wiring board concerning the present invention. It is a partial cross section explanatory view showing typically the state where one side of copper foil in the embodiment of the manufacturing method of the wiring board concerning the present invention is made to oppose to a support substrate, and it adheres. It is a partial section explanatory view showing typically the state where the resist layer was stuck on the copper foil of the intermediate in the embodiment of the manufacturing method of the wiring board concerning the present invention. It is a fragmentary sectional view showing typically the state where the copper tape was stuck around the intermediate in the embodiment of the manufacturing method of the wiring board concerning the present invention. It is a fragmentary sectional view showing typically the state of removing a resist layer from an intermediate in an embodiment of a method for manufacturing a wiring board according to the present invention. It is a fragmentary sectional view showing typically the state where a prepreg and a copper foil for lamination are laminated in order on a predetermined electrode pattern of an intermediate in an embodiment of a manufacturing method of a wiring board concerning the present invention. It is a partial section explanatory view showing typically a layered product in an embodiment of a manufacturing method of a wiring board concerning the present invention. It is a partial section explanatory view showing typically the state where copper foil was removed from the prepreg of the layered product in the embodiment of the manufacturing method of the wiring board concerning the present invention. It is a fragmentary sectional view showing typically the state where a peripheral part of a layered product in an embodiment of a manufacturing method of a wiring board concerning the present invention is pierced along an inner peripheral surface of an adhesion layer. It is sectional explanatory drawing which shows the conventional wiring board typically.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. A method for manufacturing a wiring board in the present embodiment includes a support substrate 1 and a copper foil 2 on an adhesive layer 4 as shown in FIGS. The intermediate body 5 is formed by adhering, and a predetermined electrode pattern 9 is formed on the copper foil 2 of the intermediate body 5 by a semi-additive method, and the prepreg 10 and the laminated copper foil 11 are formed on the predetermined electrode pattern 9. The laminated body 12 is formed by pressing, the support base material 1 is removed from the laminated body 12 together with the adhesive layer 4, the copper foil 2 is removed from the prepreg 10 of the laminated body 12, and the predetermined electrode pattern 9 and prepreg 10 Are aligned.

  As shown in FIG. 2 and FIG. 3, the support base material 1 is formed into a flat rectangular plate that is larger than the copper foil 2, the prepreg 10, and the copper foil 11 for lamination using a predetermined material, and is flat. The adhesive layer 4 for the copper foil 2 is adhesively held near the periphery of the surface. Although this support base material 1 is not specifically limited, for example, a metal sheet made of copper, 42 alloy or the like, aluminum, stainless steel, nickel, glass epoxy (glass epoxy) or the like is used, and rigidity, handling property, and handling property are used. From the viewpoint of ensuring the above, etc., it is formed to a thickness of 25 μm to 1 mm.

  The copper foil 2 has a thickness of 12 μm or less, for example, a thickness of 6 μm or 9 μm, in order to contribute to the removal work and thinning of the wiring board. The copper foil 2 may be used as it is. However, for convenience of work, as shown in FIGS. 1 and 2, the copper foil 2 can be detachably attached to the adhesive surface of the planar rectangular carrier substrate 3. It is preferable to be laminated and held. Although it does not specifically limit as this carrier base material 3, For example, the re-peeling film integrated with the adhesive film, the board (for example, copper foil of about 35-40 micrometers in thickness, etc.) which has predetermined | prescribed intensity | strength, etc. Can be given.

  The adhesive layer 4 is made of a silicone-based, fluorine-based, epoxy-based, or urethane-based adhesive having a thickness of 1 to 50 μm, preferably about 20 μm, and has a frame shape as shown in FIG. 1 and FIG. And is detachably adhered to the peripheral edge of one side of the copper foil 2. The material of the adhesive layer 4 is not particularly limited, but prevents unnecessary gas from being generated and diffused when the copper foil 2, the prepreg 10 and the laminated copper foil 11 are pressed, and has excellent adhesiveness. In order to obtain, and peelability, it is preferable to employ a thermosetting pressure-sensitive adhesive, that is, a silicone pressure-sensitive adhesive.

  As shown in FIG. 6 and the like, the prepreg 10 is an adhesive sheet in which a glass cloth as a reinforcing material is impregnated with a thermosetting resin to form a semi-cured B state, and has a thickness of 100 μm in order to reduce the thickness of the wiring board. Hereinafter, for example, a type having a thickness of about 30 μm is used. The prepreg 10 is formed to be smaller than the support base 1 and the copper foil 2, and is heated and pressed together with the copper foil 11 for lamination to become a copper-clad laminate.

  The laminated copper foil 11 is not particularly limited, but a type having a thickness of 18 μm or less, preferably a thickness of 12 μm or less, for example, 9 μm is used in order to contribute to thinning of the wiring board. The laminated copper foil 11 is formed to be approximately the same size as the prepreg 10, and the contact surface that contacts the prepreg 10 is selectively roughened to improve the strength.

  In the case of manufacturing a thin wiring board in the above, first, a thin copper foil 2 is detachably laminated and adhered to the surface of the prepared carrier base 3 (see FIG. 1) to ensure handling properties. The frame-shaped adhesive layer 4 is detachably adhered to the peripheral edge of the exposed one side (see the same figure), the one surface of the copper foil 2 is opposed to the surface of the support base 1 (see FIG. 2), and the adhesive layer 4 Then, the intermediate body 5 is formed by adhering detachably, and then the carrier base material 3 that is no longer necessary is peeled off from the copper foil 2 and removed.

  The adhesive layer 4 may be adhered by arranging a plurality of linear adhesives in a frame shape, or may be formed in advance in a frame shape and adhered. Further, it can be formed by applying an adhesive in a frame shape by a dispenser method or a screen printing method, followed by drying and curing. Further, when the copper foil 2 is adhered, it is preferable that the copper foil 2 is adhered while being gradually pressed from the end with a roller so that air is not interposed between the support base 1 and the copper foil 2. Since the copper foil 2 is adhered to the support substrate 1 and integrated, the thin copper foil 2 does not flutter, and the copper foil 2 can be easily handled regardless of the thickness.

  Next, a photosensitive resist layer 6 is laminated and adhered to the exposed surface of the copper foil 2 constituting the intermediate body 5 (see FIG. 3) and exposed and developed to form a predetermined electrode pattern 9 on the resist layer 6. The pattern 7 is partially patterned, and a plating electrode or protective copper tape 8 is adhered to at least a part of the periphery of the intermediate body 5 (see FIG. 4). As the resist layer 6, for example, a dry film or the like can be used. Further, the copper tape 8 can be attached to all or part of the periphery of the intermediate body 5.

  After the copper tape 8 is adhered around the intermediate body 5, the intermediate layer 5 is immersed in a plating solution (for example, an electroless copper plating solution) in a plating tank (not shown) to perform plating. A predetermined electrode pattern 9 is formed on the formation pattern 7, the intermediate body 5 is taken out from the plating tank, and the resist layer 6 that is no longer needed is removed (see FIG. 5).

  The predetermined electrode pattern 9 is preferably formed by an additive method, and the semi-additive method described above, which is particularly advantageous for miniaturization, is optimal. According to this semi-additive method, the degree of freedom of material selection is large, and a rectangular pattern shape can be easily obtained with an arbitrary conductor thickness. In addition, since the electrode pattern 9 can be formed at a pitch according to the resolution of the photosensitive plating resist, a fine circuit can be formed with higher accuracy than the subtractive method in which a circuit is formed by etching a thick metal foil. It becomes possible. Moreover, when removing the resist layer 6, although it does not restrict | limit in particular, For example, it can immerse and peel in a weak alkaline liquid.

  Subsequently, the prepreg 10 and the copper foil 11 for lamination are sequentially laminated on the predetermined electrode pattern 9 on the surface of the intermediate body 5 (see FIG. 6), and the laminated body 12 is configured by continuously pressing (see FIG. 7). A predetermined wiring pattern is formed on the exposed laminated copper foil 11 by an etching method or the like. Since the prepreg 10 is heated and pressurized on the surface of the intermediate body 5, the predetermined electrode pattern 9 is buried in the prepreg 10. Therefore, the lower surface of the predetermined electrode pattern 9 and the lower surface of the prepreg 10 do not become uneven, and are aligned and aligned.

  When the multilayer body 12 is required to have multiple layers (for example, three layers, five layers, etc.), the surface of the laminated copper foil 11 forming the multilayer body 12 is laminated on the surface via another prepreg (not shown). The laminated body 12 is multi-layered by newly laminating and pressing a copper foil (not shown) and repeatedly performing a process of patterning a predetermined wiring pattern on the new laminated copper foil as many times as necessary.

  When the multilayer body 12 is multi-layered, the strength of the multilayer body 12 is gradually increased. Therefore, unlike the case of the first copper foil 2, there is little trouble in the adhesion and lamination of the copper foil for lamination. Further, if the multilayer body 12 is multi-layered, it is possible to cope with an increase in the amount of wiring, so that it is possible to cope with high performance and miniaturization of the LSI, an increase in the number of parts, and the like. In the laminated body 12, a plurality of vias that electrically connect the layers can be formed, and each via can be plated.

  Next, if the laminated body 12 is gradually peeled and removed from the adhesive layer 4 of the support base material 1 and the unnecessary copper foil 2 is dissolved and removed from the lower surface of the prepreg 10 of the laminated body 12 by an etching method (see FIG. 8). A thin wiring board in which the predetermined electrode pattern 9 and the lower surface of the prepreg 10 are flush with each other can be manufactured. In this case, since the support base material 1 and its adhesive layer 4 are less likely to be damaged, they can be used again, and reduction of the number of parts and cost can be expected. Moreover, since the thickness of the copper foil 2 is as very thin as 12 μm or less, the work of etching and removing from the lower surface of the prepreg 10 becomes really easy.

  When the pressure-sensitive adhesive layer 4 is deteriorated to hinder the peeling of the laminated body 12 or the laminated body 12 is surely separated regardless of the adhesiveness of the pressure-sensitive adhesive layer 4, as shown in FIG. By dividing along the inner peripheral surface of the adhesive layer 4, the unnecessary peripheral portion 13 of the laminate 12 is removed together with the adhesive layer 4 and the copper tape 8, and then the prepreg of the laminate 12 from which the peripheral portion 13 has been removed. If the copper foil 2 is removed from the lower surface of the substrate 10 by an etching method, a thin wiring board in which the predetermined electrode pattern 9 and the lower surface of the prepreg 10 are aligned with each other can be manufactured. When the laminated body 12 is divided and the peripheral portion 13 is removed, for example, it is preferable to punch into a frame shape with a punching blade 14.

  According to the above manufacturing method, since the prepreg 10 and the electrode pattern 9 are in a flush relationship, it is possible to prevent the thinning of the wiring board from being hindered. In addition, since no step is generated between the prepreg 10 and the electrode pattern 9, it is effective that various operations such as mounting of solder balls may be difficult when the wiring board is used as a substrate of a surface mount semiconductor package. Can be eliminated.

  In addition, since the thin copper foil 2 is adhered to the support base material 1 by the adhesive layer 4 to ensure strength and rigidity, there is no complication or delay in handling the difficult-to-handle copper foil 2. In addition, since the copper foil 2 is adhered to effectively prevent the displacement and wrinkles, the occurrence of wiring unevenness can be suppressed and the reliability and quality of the product can be greatly improved.

  Further, the laminated body 12 is not peeled off from the entire surface of the support base material 1 in a bowed state, but an unnecessary peripheral portion 13 of the laminated body 12 is removed together with the adhesive layer 4 to remove the laminated body 12 from the support base material 1. Since it can be removed, there is no possibility that the laminated body 12 will be damaged by bending, and it can be safely removed. Furthermore, since the support base material 1 is formed with a thickness in the range of 25 μm to 1 mm, it is possible to ensure excellent rigidity or to improve handling and simplify handling.

  In the above embodiment, the copper foil 2 is adhered to the surface of the support base material 1 with the adhesive layer 4. However, the copper foil 2 is adhered to the front and back surfaces of the support base material 1 with the adhesive layer 4, and a plurality of intermediate bodies 5 are adhered. Alternatively, the laminated body 12 may be formed. Alternatively, the frame-shaped adhesive layer 4 may be adhered to the surface of the support substrate 1, and the peripheral edge portion of the opposing surface of the copper foil 2 may be detachably adhered to the adhesive layer 4. In the above embodiment, the carrier 5 is removed from the copper foil 2 after the intermediate body 5 is formed. After the adhesive layer 4 is adhered to the peripheral edge of the copper foil 2, the carrier base 3 is removed from the copper foil 2. 3 may be peeled off and removed.

  The method for manufacturing a wiring board according to the present invention can be used in the field of manufacturing interposers, coreless buildup substrates, semiconductor packages, printed wiring boards, and the like.

DESCRIPTION OF SYMBOLS 1 Support base material 2 Copper foil 2A Copper foil 3 Carrier base material 4 Adhesive layer 5 Intermediate body 6 Resist layer 7 Formation pattern 9 Electrode pattern (conductor pattern)
DESCRIPTION OF SYMBOLS 10 Prepreg 11 Copper foil 12 for laminated | stacked Laminated body 13 The peripheral part of a laminated body

Claims (4)

A method of manufacturing a wiring board that manufactures a thin wiring board using at least a support substrate and copper foil,
The support substrate and a copper foil having a thickness of 12 μm or less are opposed to each other and adhered by a substantially frame-shaped adhesive layer, and the intermediate body is configured by making this adhesive layer and the substantially peripheral edge of the copper foil detachable, A predetermined conductor pattern is formed on the intermediate copper foil by a semi-additive method, and a predetermined wiring pattern is formed on the laminated copper foil by laminating and pressing a prepreg and a laminated copper foil on the intermediate predetermined conductor pattern. After forming the laminated body by removing the support substrate and the adhesive layer from the laminated body, the copper foil is removed from the prepreg of the laminated body so that the predetermined conductor pattern and the prepreg are substantially flush with each other. A method for manufacturing a wiring board.   The method for producing a wiring board according to claim 1, wherein the adhesive layer is detachably adhered to a substantially peripheral portion of either one of the front and back surfaces of the copper foil, and the copper foil is opposed to the support base material and adhered with the adhesive layer.   A laminated copper foil is laminated and pressed on the laminated copper foil through a prepreg, and a process of forming a predetermined wiring pattern on this new laminated copper foil is repeated to make the laminated body multilayer. The manufacturing method of the wiring board of Claim 1 or 2.   After the laminate is divided along the inner peripheral portion of the adhesive layer and the peripheral portion of the laminate is removed together with the adhesive layer, the copper foil is removed from the prepreg of the laminate and the predetermined conductor pattern and the prepreg are substantially flush with each other. The method for manufacturing a wiring board according to claim 1, 2, or 3.

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