JP2010238813A - Method for manufacturing wiring board - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for manufacturing a wiring board that has no deviation in thickness and is suppressed in warpage. <P>SOLUTION: The method for manufacturing the wiring board includes a polishing process to polish upper and lower surfaces of a core substrate 10 with a set of polishing rolls arranged as a pair on upper and lower sides of a transfer path, while the core substrates 10 are kept horizontally and conveyed along the transfer path. For the process, at least two sets of the polishing rolls including a polishing roll set S1 located at the upstream side of the transfer path and a polishing roll set S2 located at the downstream side are arranged. After polishing the upper and lower surfaces of the core substrate 10 with the polishing roll set S1 at the upstream side, the core substrate 10 is reversed forward and backward and/or up and down, and in this state, the upper and lower surfaces of the core substrate 10 are polished by the polishing roll set S2 at the downstream side. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a method for manufacturing a wiring substrate, and more particularly to a method for manufacturing a wiring substrate including a step of polishing upper and lower surfaces of a core substrate having a through hole filled with a hole-filling resin with a polishing roll.

  Conventionally, a build-up multilayer wiring board is known as a wiring board for mounting electronic components such as semiconductor elements. This build-up multilayer wiring board uses a double-sided copper-clad board as a core board. The double-sided copper-clad plate is obtained by attaching copper foils to both upper and lower surfaces of an insulating plate in which a glass cloth is impregnated with a thermosetting resin such as bismaleimide triazine resin. When manufacturing a build-up multilayer wiring board, a number of through holes are formed in the core substrate by drilling, and electroless copper plating and electrolytic copper plating are sequentially applied to the inner walls of the through holes and the upper and lower copper foil surfaces. Adhere. Next, after filling and curing a hole-filling resin made of a thermosetting resin such as an epoxy resin in the through-hole with the copper plating applied, the upper and lower surfaces of the core substrate are polished and flattened by a polishing roll. To do. By this polishing, the protruding portions of the hole filling resin protruding from the upper and lower surfaces of the core substrate are removed, and the combined thickness of the copper foils on the upper and lower surfaces of the core substrate and the copper plating thereon is reduced. Next, the copper foil and copper plating on the upper and lower surfaces of the core substrate are processed into a predetermined pattern by a known subtractive method to form a core wiring conductor. Next, the wiring board is completed by alternately forming build-up resin layers and wiring layers on the upper and lower surfaces of the core board on which the core wiring conductor is formed.

  Conventionally, when polishing the upper and lower surfaces of a core substrate filled with a hole filling resin in a through hole, a polishing apparatus as shown in FIG. 4 is used. In this polishing apparatus, a plurality of drive rolls 35 and first to fourth four polishings are provided above and below a conveyance path for horizontally conveying the core substrate 36 from the right side (upstream side) to the left side (downstream side) in the drawing. Rolls 31, 32, 33 and 34 are provided. The first polishing roll 31 and the second polishing roll 32 are paired with each other to form an upstream polishing roll set 3S1, and the upper surface of the core substrate 36 is first transferred as the core substrate 36 is transferred. Polishing is performed with the first polishing roll 31 on the upper side of the path, and then the lower surface of the core substrate 36 is polished with the second polishing roll 32 on the lower side. The third polishing roll 33 and the fourth polishing roll 34 are paired with each other to form a downstream polishing roll set 3S2, and the upper surface of the core substrate 36 is moved upward as the core substrate 36 is conveyed. Additional polishing is performed by the third polishing roll 33, and the lower surface of the core substrate 36 is additionally polished by the lower fourth polishing roll 34.

JP 2001-308520 A

  However, in the conventional hole core substrate polishing process, the core substrate is always conveyed in a certain direction. Therefore, the upper and lower surfaces of the core substrate are always polished by the polishing roll from a certain direction. When the core substrate is applied to the first polishing roll, the familiarity between the polishing roll and the surface of the core substrate is poor, and the polishing roll greatly bites into the core substrate. Therefore, in the polished core substrate, the amount of polishing on the leading side in the transport direction tends to increase, and there is a problem that the thickness of the polished core substrate is uneven. At the same time, due to the difference in the amount of polishing water supplied to the upper and lower polishing rolls and the effect of gravity on the core substrate, there is a difference in the polishing amount between the upper and lower surfaces of the core substrate, which causes warping of the core substrate after polishing. There was a problem that it was easy to do. The present invention has been devised in view of such conventional problems, and it is an object of the present invention to provide a method for manufacturing a wiring board in which the thickness of the core board is not biased. Moreover, this invention makes it a subject to provide the manufacturing method of a wiring board with small curvature.

The method for manufacturing a wiring board according to the present invention transports the transport path while keeping the core substrate for the wiring board horizontal, and also sets the upper surface of the core board by a set of polishing rolls arranged in pairs above and below the transport path. In the method for manufacturing a wiring board including a polishing step for polishing the lower surface, at least two sets of a set of polishing rolls, a set of polishing rolls located on the upstream side of the conveyance path and a set of polishing rolls located on the downstream side, are provided, After polishing the upper and lower surfaces of the core substrate with a set of upstream polishing rolls, the core substrate is flipped back and forth and / or up and down, and in the inverted state, the upper and lower surfaces of the core substrate are polished with a set of downstream polishing rolls. It is characterized by doing.

  According to the method for manufacturing a wiring board of the present invention, in the polishing process of the core substrate, after the upper and lower surfaces of the core substrate are polished by the set of upstream polishing rolls, the core substrate is reversed back and forth, and in this state, the downstream side By polishing the upper and lower surfaces of the core substrate with the set of polishing rolls, it is possible to improve the uniformity of the polishing amount in the transport direction of the core substrate, and to provide a wiring substrate with no bias in the thickness of the core substrate. Furthermore, after polishing the upper and lower surfaces of the core substrate by a set of upstream polishing rolls, the core substrate is turned upside down, and in that state, the upper and lower surfaces of the core substrate are polished by a set of downstream polishing rolls, It is possible to improve the uniformity of the polishing amount of the upper and lower surfaces of the core substrate and provide a wiring substrate with less warpage.

It is a schematic sectional drawing for demonstrating the embodiment in the manufacturing method of the wiring board of this invention. It is a principal part expanded sectional schematic diagram for demonstrating the core board | substrate grind | polished by the manufacturing method of this invention. It is a principal part expanded sectional schematic diagram for demonstrating the core board | substrate grind | polished by the manufacturing method of this invention. It is a schematic sectional drawing for demonstrating the method to manufacture a wiring board in a prior art.

Next, preferred embodiments of the present invention will be described with reference to the drawings.
First, FIG. 2 shows an enlarged schematic cross-sectional view of the main part of the core substrate 10 polished by the manufacturing method of the present invention. As shown in FIG. 2, the core substrate 10 has conductor layers 12 made of copper foil and copper plating on both upper and lower surfaces of an insulating plate 11 in which a glass cloth is impregnated with a thermosetting resin such as bismaleimide triazine resin. A plurality of through holes 13 are formed from the upper surface to the lower surface. A conductor layer 12 made only of copper plating is deposited on the inner wall of the through hole 13 and the through hole 13 is filled with a filling resin 14. The hole-filling resin 14 has projecting portions that project from the upper and lower surfaces of the core substrate 10. Then, by polishing the upper and lower surfaces of the core substrate 10 by the manufacturing method of the present invention, as shown in FIG. 3, the protruding portions of the hole filling resin 14 protruding from the upper and lower surfaces of the core substrate 10 are removed, and The thickness of the lower conductor layer 12 is reduced. 2 and 3 show only a part of the core substrate 10, it is actually a large panel having a vertical and horizontal size of 500 to 600 mm.

  Next, a method for polishing the upper and lower surfaces of the core substrate 10 will be described with reference to FIG. As shown in FIG. 1, the polishing apparatus used in this example has a plurality of drive rolls 5 above and below a conveyance path that horizontally conveys the core substrate 10 from the right side (upstream side) to the left side (downstream side). And first to fourth polishing rolls 1, 2, 3, and 4. The first polishing roll 1 and the second polishing roll 2 are paired with each other to form an upstream set S1 of polishing rolls. Polishing is performed with the first polishing roll 1, and then the lower surface of the core substrate 10 is polished with the second polishing roll 2. Further, the third polishing roll 3 and the fourth polishing roll 4 are paired with each other to form a set S2 of the downstream polishing roll, and the upper surface of the core substrate 10 is transported as the core substrate 10 is conveyed. Is additionally polished by the third polishing roll 3, and then the lower surface of the core substrate 10 is additionally polished by the fourth polishing roll 4.

  Further, the polishing apparatus shown in FIG. 1 includes a reversing device (not shown) between the upstream polishing roll set S1 and the downstream polishing roll set S2. Then, after the upper and lower surfaces of the core substrate 10 conveyed on the conveyance path are polished by the upstream set S1 of polishing rolls, the reversing device is used to rotate the vertical rotation axis perpendicular to the conveyance direction of the conveyance path. The front and back and the top and bottom are reversed about the center, and in this state, the top and bottom surfaces are additionally polished by the downstream set S2 of polishing rolls. In FIG. 1, the surface indicated by the thick line of the core substrate 10 is the surface that becomes the top side and the top surface side when being polished by the upstream set S1 of polishing rolls.

  The core substrate 10 is inverted back and forth between the upstream set S1 and the downstream set S2, whereby the upper and lower surfaces of the core substrate 10 are alternately turned 180 degrees in the horizontal direction from the opposite side. As a result, the uniformity of the polishing amount in the transport direction of the core substrate 10 is improved. Therefore, it is possible to provide a wiring substrate in which the core substrate 10 has no thickness deviation. Further, the core substrate 10 is inverted up and down between the upstream set S1 and the downstream set S2, so that the amount of cleaning water and the influence of gravity are affected by the upper and lower surfaces of the core substrate 10. Thus, the uniformity of the polishing amount on the upper and lower surfaces of the core substrate 10 is improved. Therefore, it is possible to provide a wiring board with small warpage. By arranging the same number of sets of polishing rolls on the upstream side and the downstream side of the position where the core substrate 10 is reversed, the polishing state of the upper and lower surfaces of the core substrate 10 can be made substantially uniform. it can. Therefore, it is preferable to arrange the same number of sets of polishing rolls on the upstream side and the downstream side of the position where the core substrate 10 is inverted.

  The present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the gist of the present invention. For example, in the above-described embodiment, the upstream side The core substrate 10 is inverted back and forth and up and down between the set S1 of polishing rolls and the set S2 of downstream polishing rolls, but the core substrate 10 is only back and forth around the rotation axis perpendicular to the horizontal plane. It may be reversed, or it may be reversed only up and down around a rotation axis parallel to the conveyance direction of the conveyance path. Further, different sets of polishing rolls may be arranged on the upstream side and the downstream side of the position where the core substrate 10 is inverted.

DESCRIPTION OF SYMBOLS 1 1st grinding | polishing roll 2 2nd grinding | polishing roll 3 3rd grinding | polishing roll 4 4th grinding | polishing roll 5 Conveyance roll 10 Core board | substrate 11 Insulation board 12 Conductive layer 13 Through hole 14 Filling resin S1 Set of polishing roll of upstream side S2 Downstream polishing roll set

Claims (2)

  Wiring including steps of maintaining a core substrate for a wiring substrate horizontally and transporting the transport path, and polishing upper and lower surfaces of the core substrate by a set of polishing rolls arranged in pairs above and below the transport path In the substrate manufacturing method, at least two sets of the polishing rolls are provided on the upstream side and the downstream side of the conveyance path, and the upper and lower surfaces of the core substrate are polished by the upstream polishing roll set, A method of manufacturing a wiring board, comprising: rotating a core substrate up and down and / or up and down, and polishing the upper and lower surfaces of the core substrate with the downstream polishing roll set in the inverted state. 2. The method of manufacturing a wiring board according to claim 1, wherein the same number of sets of polishing rolls are disposed on the upstream side and the downstream side of the position where the core substrate is reversed back and forth.

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