JP2004342930A - Multilayer substrate having non-through conduction hole - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To make realizable a small and high-density mold chip having an end electrode which exhibits highly reliable electrical connection and solder joint, even in a condition where a member for preventing entry of sealing resin into a through hole is stuck onto an upper surface side of the through hole. <P>SOLUTION: A circuit board provided with the non-through conduction hole for an end electrode on a dividing and cutting line for dicing comprises an upper circuit board having a part-connecting land for mounting an electronic part or an electronic part element thereon, a second blind via (B2) of a lower circuit board which is disposed on the dividing and cutting line, and a first blind via (B1) for electrically connecting the part-connecting land of the upper circuit board and the second blind via (B2) of the lower circuit board. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a printed wiring board, and more particularly, to a multilayer board serving as a base board for a mold chip component forming an end face electrode.
[0002]
[Prior art]
Conventionally, when forming an end face electrode on a substrate, a through-hole hole is provided in a straight line in the vicinity of the outer side surface of the printed wiring board, and the through-hole hole is divided and cut substantially on the center line of the through-hole hole. An end surface electrode having a semi-cylindrical inside and exposed to the outside is formed.
A semiconductor integrated circuit element, an electronic component element, and an electronic component are mounted on a substrate, and thereafter, the wiring pattern of the substrate, the semiconductor integrated circuit element, the electronic component element, and the electronic component are molded with a resin and sealed with a resin. In order to form a mold chip component having an end face electrode, a member (film, tape, tape, etc.) for preventing resin from intruding on the upper surface side of the through-hole hole so as to prevent sealing resin from entering the inside of the through-hole hole. Substrate, etc.).
As one example, there is an end face through-hole wiring board disclosed in Japanese Patent Application Laid-Open No. 10-65298.
This is an end-face through-hole wiring board in which a non-through conductive through-hole is formed in which one end of the through-hole is open and the other end is closed by an outer conductor. In other words, the upper surface of the through conduction hole is closed with the outer layer conductor using the outer layer conductor as a member for preventing the intrusion of the sealing resin.
The outer layer conductor of the non-through conductive through-hole is usually a thin metal film of 0.05 mm or less. Therefore, in the transfer molding method in which the sealing pressure with resin is high, the thin metal film of the non-through conductive hole is high due to the high pressure. Is collapsed or damaged.
In the module board disclosed in Japanese Patent Application Laid-Open No. 2002-164658, an electronic component is mounted on the surface of the multilayer board, and electrodes used for connection to the outside are provided on an intermediate layer on the side of the multilayer board. This is a module substrate in which a conductive groove is formed in a substrate and a bottom layer substrate, and a surface layer substrate in which the conductive groove is not formed is provided in a surface layer on which electronic components are mounted.
In this module substrate, through holes for end surface electrodes are formed on the side surfaces of the intermediate layer substrate and the bottom layer substrate, but through holes for end surface electrodes are formed in the surface layer substrate bonded onto the intermediate layer substrate. Not something.
The above-mentioned module substrate is a three-layer substrate in which three substrates, a surface layer substrate, an intermediate layer substrate, and a bottom layer substrate, are bonded to each other, and there is a problem in making the module thinner.
Also, when the surface layer substrate is bonded onto the through-hole for the end face electrode penetrating through the intermediate layer substrate and the bottom layer substrate, an adhesive resin such as a prepreg flows into the through-hole and the upper surface of the conductive groove formed from the through-hole. No conductor layer is formed on the back surface of the surface layer substrate.
Therefore, there is a problem as a base substrate for a high-definition electronic component required to be thinner, and poor solder wettability is likely to occur also as an end face electrode.
[0006]
[Patent Document 1]
JP-A-10-65298.
[Patent Document 2]
JP-A-2002-164658.
[0007]
In order to mount an electronic component and an electronic component on a substrate, and then seal the mounted electronic component and the electronic component with a resin to obtain a mold chip component having end electrodes, A member (insulating base material, insulating tape, film, sheet, etc.) for preventing resin from intruding on the upper surface side of the through-hole hole so that the sealing resin does not enter the inside of the through-hole hole provided in Blocking member).
The lamination of the blocking members described above has increased the density and reduced the connection reliability of the end face electrodes.
In particular, recently, miniaturization and high-density of molded chip parts and high electrical and solder connection reliability of end face electrodes are required.
In particular, high reliability is required in the transfer molding method for mass-producing thin high-density mold resin parts at high temperature and pressure (140 to 180 ° C., 20 to 30 tons).
[0008] In a wiring board having a non-through conductive hole structure in which the upper surface of a through conductive hole is closed by using an outer layer conductor disclosed in Japanese Patent Application Laid-Open No. H10-65298, a resin blocking land and an electronic component connection land that block the upper surface of the through conductive hole In addition, wiring patterns are concentrated on the same surface layer, and there is a problem in high-density mounting.
In addition, since the outer layer conductor that closes the upper surface of the non-through conductive hole is usually a thin metal film, it cannot be used as a connection land for electronic parts for wire-bonding. As a result, the metal coating of the non-through conductive hole is depressed or broken, or the non-through conductive hole is damaged.
Furthermore, in the case of a wiring board having a thin non-through conductive hole structure, warpage or twisting occurs due to insufficient strength of the wiring board when mounting electronic components and electronic components, resulting in poor mounting and poor solder wettability.
A module board disclosed in Japanese Patent Application Laid-Open No. 2002-164658 is a board that becomes a separable unit (printed circuit term issued by Japan Printed Circuit Industries Association) in one assembly system. is there.
However, there have been many problems with a thin base board which requires miniaturization and high density of a mold chip component, high electrical end face electrodes, and high reliability of solder connection.
[0010]
[Means for Solving the Problems]
In order to solve the above-mentioned problem, in a wiring board having a non-through conductive hole for an end face electrode on a division cutting line for dicing, an upper wiring board having a component connection land for mounting an electronic component or an electronic component element, The second blind via (B2) of the lower wiring board arranged on the divisional cutting line, and the second blind via (B2) of the lower wiring board electrically connecting the component connection land of the upper wiring board and the second blind via (B2) of the lower wiring board. And a blind via (B1).
In a wiring board having a non-through conductive hole for an end face electrode on a dicing cut line, an upper conductor (L1) of the wiring board on which electronic components and electronic component elements are mounted, and a lower conductor of the wiring board (L3) and an inner layer conductor (L2) of the wiring board,
An upper wiring board provided with a component connection land for mounting an electronic component or an electronic component element, a second blind via (B2) for an end face electrode disposed on the lower wiring board on the division cutting line, and the upper wiring A first blind via (B1) for electrically connecting a component connection land of the board to a second blind via (B2) of the lower wiring board; and a multi-layer board having a non-through conductive hole. And
[0012]
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a manufacturing process for forming a multilayer substrate having a non-through conductive hole according to the present invention will be described with reference to FIG.
First, as shown in FIG. 2A, an adhesive 3, such as an emulsion, a film, or a sheet, is adhered to the base material 2 side of a single-sided copper-clad laminate having a copper foil 4 on the lower surface to form a lower wiring board 1. After the adhesive is semi-cured as shown in FIG. 2B, a predetermined portion of the lower wiring substrate 1 is subjected to a drilling process by an NC drilling machine to form a through hole 9. Next, as shown in FIG. 2C, a copper foil 6 is laminated and pressed on the adhesive 3 of the lower wiring board 1 in which a predetermined portion of the lower wiring board 1 is punched and a through hole 9 is formed. And stick them together.
Next, as shown in FIG. 2D, a predetermined portion of the copper foil 6 on the upper surface of the lower wiring substrate 1 is etched to form an inner layer pattern (L2) as a circuit.
FIG. 2E shows an insulating layer 7 and a copper foil 8 laminated and pressed on the upper surface where an inner layer pattern (L2) is formed in a circuit at a predetermined location of the copper foil 6 on the upper surface of the lower wiring board 1. The upper wiring substrate 10 is formed.
Next, as shown in FIG. 2 (f), the insulating layer 7 between the upper outer layer copper foil 8 and the inner layer pattern (L2) is formed on a predetermined portion of the upper wiring board 10 by carbon dioxide laser processing. Is removed to form a non-through hole 11.
Then, as shown in FIG. 2 (g), electroless copper plating is performed to form a plating layer 12, and a predetermined non-through conductive hole 15 of the upper wiring board 10 and a predetermined non-through conductive hole 16 of the lower wiring board 1 are formed. To form Thereafter, a predetermined portion is etched to form an upper surface outer layer pattern (L1) and a lower surface outer layer pattern (L3).
A via opening only on one side of the wiring board is called a blind via, and is a non-through conductive hole for electrically connecting the outer conductor and the inner conductor. A non-through conductive hole 15 formed in the upper wiring board 10 for electrically connecting the upper outer layer pattern (L1) and the inner layer pattern (L2) is defined as a first blind via (B1), and the inner layer pattern is formed. The non-through conductive hole 16 for electrically connecting (L2) and the lower surface outer layer pattern (L3) is used as a second blind via (B2). In some cases, formation of a solder resist, Ni-Au plating, or the like is performed due to the necessity of improving reliability, improving solderability, and wire bonding work.
The structure of a multilayer substrate having a non-through conductive hole according to the present invention will be described with reference to FIG. A three-layer conductor structure including an upper conductor (L1) of the wiring board, a lower conductor (L3) of the wiring board, and an inner conductor (L2) of the wiring board, and is a component connection for mounting an electronic component or an electronic component element. The land 17 is provided on the upper surface conductor (L1) of the wiring board. A second blind via (B2), which is a non-through conductive hole for an end face electrode disposed on the lower wiring substrate 1 on the divisional cutting line 18, and the component connection lands 17 of the upper wiring substrate 10 and the lower wiring substrate 1; A multilayer substrate having a non-through conductive hole made of the first blind via (B1) of the upper wiring board 10 which is a non-through conductive hole for electrically connecting the second blind via (B2).
The dicing is performed by dicing with a cutting line that passes through a substantially central portion of a non-through conductive hole for electrically connecting an inner layer pattern (L2) formed on the lower wiring board 1 and a lower outer layer pattern (L3). It is a blind via for forming an electrode.
In response to miniaturization of high-density molded chip components and high electrical and solder connection reliability of the end face electrodes, especially as a base substrate for mass-producing thin and high-density chip components by the transfer molding method. The thickness of the insulating layer of the upper wiring board is set to 0.03 to 0.200 mm. The thickness of the base material of the lower wiring board in which the non-through conduction hole for the end face electrode is formed is 0.20 to 0.50 mm. The hole diameter of the non-through conductive hole is preferably 0.30 to 1.00 mm for the second blind via (B2) for the end face electrode. The diameter of the first blind via (B1) is preferably φ0.10 to φ0.30 mm.
That is, the multi-layer board having the non-through conduction hole of the present invention does not have the through hole penetrating the upper and lower surfaces of the wiring board.
[0017]
According to the present invention, a multi-layer board having a non-through conductive hole which does not have a through-hole penetrating the upper and lower surfaces of the wiring board has a highly reliable electrical and solder connection. Via (B2) can be formed. In addition, since the upper wiring board is not provided with the blind vias (B2) for the end face electrodes and is mainly composed of the component connection lands, the chip components can be reliably mounted at a high density.
[Brief description of the drawings]
FIG. 1 is an embodiment of a multilayer substrate having a non-through conduction hole according to the present invention.
FIG. 2 is a manufacturing process diagram illustrating a multilayer substrate having a non-through conductive hole according to the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Lower wiring board, 2 ... Base material, 3 ... Adhesive, 4 ... Lower surface copper foil,
6 ... copper foil, 7 ... insulating layer, 8 ... copper foil, 9 ... through hole,
10: upper wiring board, 11: non-through hole, 12: plating layer,
15, 16: non-through conduction hole, 17: component connection land, 18: division cutting line.

Claims (2)

In a wiring board having a non-through conductive hole for an end face electrode on a dicing division cutting line, an upper wiring substrate provided with a component connection land for mounting an electronic component or an electronic component element, and a lower wiring arranged on the division cutting line A second blind via (B2) of the board, and a first blind via (B1) for electrically connecting the component connection land of the upper wiring board and the second blind via (B2) of the lower wiring board. , Comprising a non-through conductive hole. An upper conductor (L1) of a wiring board on which electronic components and electronic component elements are mounted, a lower conductor (L3) of the wiring board, and a wiring board having a non-through conductive hole for an end surface electrode on a dicing division cutting line; A three-layer conductor structure comprising an inner conductor (L2) of the wiring board;
An upper wiring board provided with a component connection land for mounting an electronic component or an electronic component element, a second blind via (B2) for an end face electrode disposed on the lower wiring board on the division cutting line, and the upper wiring A first blind via (B1) for electrically connecting a component connection land of the board to a second blind via (B2) of the lower wiring board; and a multi-layer board having a non-through conductive hole. .

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