JP2003282764A - Wiring board of multiple allocation - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a wiring board of multiple allocation on which metallized wiring conductors, outside connecting metallized layers, and sealing metallized layers of wiring board areas arranged on a ceramic mother substrate can be coated with plated metallic layers by electroplating. <P>SOLUTION: In the central part of the ceramic mother substrate 1, a number of wiring board areas 2, each of which has a recess 2a for housing an electronic component on its upper surface, and at the same time, to each of which metallized wiring conductors 6 led out to corners of the outer periphery of the recess 2a from the bottom face of the section 2a and a sealing metallized layer 7 surrounding the recess 21 are adhered, and arranged longitudinally and transversally. In addition, through holes 4 the internal surfaces of which are coated with the outside connecting metallized layers 8 electrically connected to the wiring conductors 6 are formed at the intersections of the boundary lines dividing the wiring board areas 2. The diagonally faced two of the sealing metallized layers 7 and the outside connecting metallized layers 8 at each wiring board area 2 are electrically connected to each other. <P>COPYRIGHT: (C)2004,JPO

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a small-sized wiring for accommodating electronic components in a central portion of a ceramic mother substrate formed by laminating a plurality of insulating layers. The present invention relates to a multi-cavity wiring board in which a large number of substantially rectangular wiring board regions serving as substrates are formed vertically and horizontally and integrally arranged. 2. Description of the Related Art Conventionally, a small-sized wiring board used for an electronic component housing package for housing an electronic component such as a semiconductor element or a quartz oscillator is made of, for example, a ceramic such as an aluminum oxide sintered body. And a substantially square-shaped insulating base having a concave portion for accommodating an electronic component on the upper surface and having a cutout portion having an arc-shaped side surface in a top view at each outer peripheral corner portion. A metallized wiring conductor derived from the bottom surface of the concave portion of the insulating base to each outer peripheral corner, and a metallized wiring conductor derived from the side surface of the cutout of each outer peripheral corner to the outer peripheral surface of the lower surface of the insulating base to the outer peripheral corner. An external connection metallization layer applied so as to be electrically connected, and a frame-shaped sealing metallization applied on the upper surface of the insulating base so as to surround the recess. Layer. According to this wiring board, the electronic component is accommodated in the concave portion of the insulating base, and the electrode of the electronic component is electrically connected to the metallized wiring conductor on the bottom surface of the concave portion via a conductive adhesive or a bonding wire. After connecting and then
An electronic device as a product is obtained by joining a metal cover to the sealing metallization layer on the upper surface of the insulating substrate so as to cover the concave portion and hermetically housing the electronic component in the concave portion. Of the electronic components mounted and accommodated on the external electric circuit board by connecting the external connection metallized layer applied from the side face to the lower face of each outer peripheral corner to the wiring conductor of the external electric circuit board via solder. The electrodes will be electrically connected to an external electric circuit. [0004] In recent years, with the recent demand for miniaturization of electronic devices, the size of such a wiring board has become extremely small, about several mm square, and a large number of wiring boards must be handled. In order to facilitate the manufacture of the wiring board and the electronic device, and to efficiently manufacture the wiring board and the electronic device, a large number of wiring boards are simultaneously and intensively obtained from one large-area ceramic mother board. It is manufactured in the form of an individual wiring board. This multi-cavity wiring board has a concave portion for accommodating an electronic component on an upper surface thereof in a central portion of a substantially flat ceramic mother substrate formed by laminating a plurality of insulating layers. A large number of substantially square wiring board regions are vertically and horizontally arranged integrally with a metallized wiring conductor extending from the bottom surface of the concave portion to each peripheral corner thereof and a frame-shaped encapsulating metallizing layer on the upper surface surrounding the concave portion. In addition, a circular through-hole is formed so as to cut off each outer corner of each wiring board region on the intersection of the boundary line that separates each substrate region, and each wiring board is formed from the inner wall of the through-hole. Over the outer peripheral portion of the lower surface of the region, an external connection metallization layer electrically connected to each metallized wiring conductor led to the outer peripheral corner portion cut out by the through hole extends over the entire periphery of the inner wall of the through hole. It has been deposited. Then, after the electronic components are accommodated in the recesses of the respective wiring board regions such that the respective electrodes and the metallized wiring conductors are electrically connected, the ceramic motherboard is divided into the respective wiring board regions to obtain a large number. Are manufactured simultaneously and intensively. In such a multi-cavity wiring board, the metallized wiring conductors, the metallized layer for external connection and the metallized layer for sealing are prevented from being oxidized and corroded, and the metallized wiring conductors and the electrodes of the electronic component are connected to each other. In order to improve the electrical connection between the metallization layer for external connection and the electrical connection between the metallization layer for external connection and the wiring conductor of the external electric circuit board, and the bonding between the metallization layer for sealing and the metal cover, For example, a nickel plating layer having a thickness of about 1 to 10 μm and a gold plating layer having a thickness of about 0.1 to 3 μm are sequentially coated on the exposed surfaces of the conductor, the metallization layer for external connection, and the metallization layer for sealing by electrolytic plating. Is being worn. Further, in order to electrically ground the metal lid to be joined to the metallizing layer for sealing, the metallizing layer for sealing in each wiring board region and one of the metallizing layers for external connection are electrically connected. Conventionally, in such a multi-cavity wiring board, to apply a nickel plating layer or a gold plating layer to each metallized wiring conductor, a metallized layer for external connection, and a metallized layer for sealing by an electrolytic plating method, All metallized wiring conductors are electrically connected by providing a plurality of metallized wiring conductors for electrically connecting the metallized wiring conductors adjacent to each other between the insulating layers constituting the ceramic mother board across the boundaries of the wiring board regions. The metallized wiring conductors and the exposed surfaces of the metallized layers for external connection and the metallized layers connected to the metallized wiring conductors are supplied by supplying a charge for electrolytic plating through the connecting conductors. A method of electrolytic plating. Since the metallized wiring conductors are electrically connected to each other by the connection conductors for plating conduction across the boundaries of the wiring board regions, the metallized wiring conductors are divided into the wiring board regions after the ceramic motherboard is divided into the wiring board regions. , Respectively, are electrically independent. [0009] However, recent wiring boards have been miniaturized and densified.
The distance between adjacent metallized wiring conductors has become extremely narrow. Also, in a multi-cavity wiring board for obtaining such a wiring board, a plurality of metallized wiring conductors adjacent to each other are electrically connected to each other across the boundary of each wiring board region, and a plurality of connection conductors for plating conduction are provided. Has become extremely difficult. Therefore, the metallized wiring conductors are electrically connected in common by such connection conductors, and the metallized wiring conductors, the metallized layers for external connection, and the metallized layers for encapsulation are coated with a plating metal layer by electrolytic plating. Has become difficult. The present invention has been made in view of the above-mentioned conventional problems, and an object of the present invention is to provide a method of connecting metallized wiring conductors between metallized wiring conductors of each wiring board region arranged on a ceramic mother board. A plating metal layer is applied to each metallized wiring conductor, a metallized layer for external connection, and a metallized layer for encapsulation by an electrolytic plating method without providing a connecting conductor for plating conduction connecting across the boundary of the substrate region. It is an object of the present invention to provide a multi-cavity wiring board capable of performing the above. According to the present invention, there is provided a multi-piece wiring board for accommodating electronic components on a top surface of a ceramic mother board formed by laminating a plurality of insulating layers. Numerous substantially rectangular wiring boards having a recess and four metallized wiring conductors extending from the bottom surface of the recess to the respective corners on the outer periphery thereof and a frame-shaped sealing metallization layer attached to the upper surface surrounding the recess. The regions are arranged vertically and horizontally, and a metallization layer for external connection electrically connected to the metallized wiring conductor is applied over the entire circumference of the inner wall on the intersection of the boundary lines separating the wiring substrate regions. A multi-cavity wiring board formed by forming through holes, wherein a pair of the metallization layer for sealing and the metallization layer for external connection in each of the wiring board areas has a pair. The two corners are electrically connected to each other. According to the multi-cavity wiring board of the present invention, the metallization layer for sealing of each wiring board region arranged and formed on the ceramic mother substrate and the through hole at the intersection of the boundary line separating each wiring board region are provided. Since two of the metallization layers for external connection adhered to the inner wall, which are located diagonally to the respective wiring substrate regions, are electrically connected to each other, the external connection adhered to the inner wall of each through hole is formed. The metallization layers for the wiring board regions are diagonally and continuously electrically connected to each other at the diagonal positions via the metallization layers for sealing. By supplying a charge for electrolytic plating to the metallized layer for external connection that has been applied and performing electrolytic plating, all metallized layers for external connection, metallized wiring conductors connected to the metallized layer, and metallized metallization for sealing are provided. The plated metal layer by electrolytic plating layer can be deposited. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A multi-cavity wiring board according to the present invention will be described with reference to the accompanying drawings. FIG. 1 is a top view showing an example of an embodiment of a multi-cavity wiring board of the present invention,
FIG. 2 is a cross-sectional view of the multi-piece wiring board shown in FIG. In the figure, reference numeral 1 denotes a ceramic mother board, and 2 denotes a wiring board area. The ceramic mother substrate 1 is formed by laminating two insulating layers 1a and 1b made of a ceramic material such as an aluminum oxide sintered body, an aluminum nitride sintered body, a mullite sintered body, and a glass-ceramic. A plurality of substantially rectangular wiring board regions 2 are formed at the center of the plate, and are vertically and horizontally arranged in a line at a center portion of the wiring board region 2 by a boundary line 3. Line 3
A circular through-hole 4 is formed on the intersection of. Further, a frame-shaped waste area 5 is formed in the outer peripheral portion. Such a ceramic mother substrate 1 is manufactured by a ceramic green sheet laminating method. Specifically, ceramic green sheets for the insulating layers 1a and 1b are prepared, and through holes are formed in these ceramic green sheets. It is manufactured by punching out a punching hole or the like for 4 and then laminating and firing it at a high temperature. Each of the wiring board regions 2 arranged in the center of the ceramic mother substrate 1 is a region that becomes a small wiring board for an electronic device, and accommodates electronic components in the center of the upper surface of each. The four metallized wiring conductors 6 to which the electrodes of the electronic components are electrically connected from the bottom surface of the concave portion 2a to each of the outer peripheral corners in contact with the through hole 4 are formed in the concave portion 2a. A sealing metallization layer 7 to which a metal lid for hermetically sealing the recess 2a is bonded is formed on the surrounding upper surface. In addition, from the inner wall of the through hole 4 formed on the boundary line 3 separating the wiring board regions 2 to the outer peripheral corner of the lower surface of each wiring board region 2, the outer peripheral angle of each wiring board region 2 in contact with the through hole 4 An external connection metallization layer 8 electrically connected to the metallized wiring conductor 6 led to the portion is formed over the entire periphery of the through hole 4. These metallized wiring conductors 6, metallized layers 7 for sealing, and metallized layers 8 for external connection
Are formed from metal powders of metal such as tungsten, molybdenum, copper, and silver. The recess 2a of each wiring board region 2 as described above
Are concave portions 2 in the ceramic green sheet for the insulating layer 1b.
Each metallized wiring conductor 6, sealing metallized layer 7, and external connection metallized layer 8 are formed by punching out a substantially square through hole for a.
A metallized wiring conductor 6, a metallized layer 7 for sealing, and a metallized paste for a metallized layer 8 for external connection are printed and applied in a predetermined pattern on the upper and lower surfaces of the ceramic green sheet for use or the side surfaces of the punched holes for the through holes 4. It is formed by keeping. Each wiring board region 2 has its recess 2
a, electronic components such as a semiconductor element and a quartz oscillator are accommodated, and each electrode of the electronic component is electrically connected to the metallized wiring conductor 6 in the recess 2a via, for example, a solder bump or a bonding wire. Thereafter, the electronic component is hermetically sealed in the recess 2a by joining a metal lid to the sealing metallization layer 7 on the upper surface of each wiring board region 2 via a brazing material. By dividing the wiring board area 2 along the boundary 3, a large number of electronic devices are obtained. In this semiconductor device, the externally connected metallized layer 8 attached from the outer peripheral corner side to the lower outer peripheral corner is connected to the wiring conductor of the external electric circuit board via solder, thereby forming the external electric circuit. The electronic components mounted on the substrate and housed inside are electrically connected to the external electric circuit. In order to divide the ceramic mother substrate 1 along the boundary 3 between the wiring substrate regions 2, division grooves are formed on the upper and lower surfaces of the ceramic mother substrate 1 on the boundary 3 between the wiring substrate regions 2. A method of bending along the dividing groove or a method of cutting the ceramic mother substrate 1 along a boundary 3 of each wiring board region 2 by a diamond cutter, a laser cutter or the like is adopted. In this multi-cavity wiring board, the metallized wiring conductors 6 and the metallizing layer 7 for sealing in each wiring board area 2 and the inner wall of the through hole 4 cover the outer peripheral corner of the lower surface of each wiring board area. Each of these metallized wiring conductors 6 is provided on the surface of the metallized layer 8 for external connection.
In addition, the metallization layer 7 for sealing and the metallization layer 8 for external connection are prevented from being oxidized and corroded, and the connection between each metallized wiring conductor 6 and the electrode of the electronic component and the bonding between the metallization layer 7 for sealing and the metal cover are performed. In order to improve the connection between the external connection metallization layer 8 and the wiring conductor of the external electric circuit board, a nickel plating layer having a thickness of about 1 to 10 μm and a 0.1 to 3 μm thickness are usually used. A gold plating layer having a thickness is sequentially applied by an electrolytic plating method. The disposal area 5 formed on the outer peripheral portion of the ceramic mother substrate 1 is an area for facilitating the handling of the multi-piece wiring board when manufacturing or transporting the multi-piece wiring board. And between the insulating layers 1a and 1b,
A frame-like plating conduction metallization layer 9 electrically connected to the outermost metallization layer 8 of the external connection metallization layer 8 attached to the inner wall of each through hole 4 is provided.
Further, a metallization terminal 10 for plating conduction electrically connected to the metallization layer 9 for plating conduction is formed on the outer peripheral side surface. The metallization layer 9 for plating conduction and the metallized terminal 10 for plating conduction apply charges for electrolytic plating to the metallized wiring conductors 6, the metallized layers 7 for encapsulation and the metallized layers 8 for external connection in the wiring board regions 2. Each metallized wiring conductor 6, sealing metallized layer 7, and metallized layer 8 for external connection are formed from a metallized terminal 10 for metallization through a metallization layer 9 for metallization for plating. Is supplied and the electrolytic plating is performed, whereby a nickel plating layer and a gold plating layer are sequentially deposited on the surface of each metallized wiring conductor 6, metallizing layer 7 for sealing, and metallizing layer 8 for external connection. Such a metallization layer 9 for plating conduction and a metallized terminal 10 for plating conduction are formed of metal powder metalization of tungsten, molybdenum, copper, silver or the like.
It is formed by printing and applying a metallization paste 9 for plating conduction metallization layer 9 and plating conduction metallization terminal 10 in a predetermined pattern on the upper surface, lower surface, and outer peripheral side surface of the ceramic green sheet for 1b. In the multi-cavity wiring board of the present invention, each of the metallization layer 7 for sealing in each wiring board area 2 and the metallization layer 8 for external connection attached to the inner wall of each through hole 4 is provided. The two diagonally located wiring board regions 2 are electrically connected to each other, which is important. As described above, of the metallization layer 7 for sealing in each wiring board region 2 and the metallization layer 8 for external connection adhered to the inner wall of each through hole 4, two of which are located diagonally to each wiring board region 2. Are electrically connected to each other, the metallization layers 8 for external connection applied to the inner wall of each through hole 4 are the metallization layers for sealing which are located at the diagonal positions of the wiring board regions 2. 7 and electrically connected obliquely continuously through the metallization layer 9 via the plating metallization layer 9 to the external connection metallization layer 8 attached to the inner wall of the outermost through hole 4. By supplying a charge for the electrolytic plating and performing the electrolytic plating, all the metallized layers 8 for external connection, the metallized wiring conductors 6 connected thereto and the metallized layer 7 for sealing are covered with a plated metal layer by electrolytic plating. Dressed Rukoto can. Thus, according to the multi-cavity wiring board of the present invention, the electronic component is mounted and fixed in the concave portion 2a of each wiring board area 2, and the electrode of the electronic component and each metallized wiring conductor 6 are electrically connected. After connecting to the metallization layer 7 on the upper surface of each wiring board region 2 with a metal cover via a brazing material, and dividing the ceramic mother substrate 1 into each wiring board region 2, Electronic devices are manufactured simultaneously and intensively. In this case, in each wiring substrate region, the two metallized wiring conductors 6 connected to the external connection metallization layer 8 to which the sealing metallization layer 7 is connected are electrically connected to each other even after the ceramic mother substrate 1 is divided. Since they are connected, these two metallized wiring conductors 6 may be used, for example, as metallized wiring conductors 6 for grounding. Alternatively, after the metallized wiring conductor 6, the metallized layer 7 for encapsulation, and the metallized layer 8 for external connection are coated with a plated metal layer by electrolytic plating,
By cutting one or both of the connection portions between the sealing metallization layer 7 of each wiring board region 2 and the two external connection metallization layers 8 connected thereto, for example, by irradiating a laser beam as necessary, One or both of the metallized wiring conductors 6 that are pneumatically connected to the metallization layer 7 may be electrically independent from the metallization layer 7. It should be noted that the present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the scope of the present invention. In one example, the ceramic mother substrate 1 is formed by laminating two insulating layers 1a and 1b, but the ceramic mother substrate 1 may be formed by laminating three or more insulating layers. According to the multi-cavity wiring board of the present invention,
The metallization layer for sealing of each wiring substrate region arranged and formed on the ceramic mother substrate, and the metallization layer for external connection adhered to the inner wall of the through hole on the intersection of the boundary line separating each wiring substrate region, Since the two diagonally located diagonals of each wiring board region are electrically connected to each other, each external connection metallization layer applied to the inner wall of each through hole is positioned at the diagonal diagonal of each wiring board region. Are electrically connected obliquely and continuously via the metallizing layer for sealing, and as a result, the metallizing layer for external connection attached in the outermost through-hole is electrolytically plated. To supply an electric charge to perform plating, thereby depositing a plating metal layer by electrolytic plating on all metallized layers for external connection, metallized wiring conductors connected to the metallized layers, and metallized layers for sealing. Door can be.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a top view showing an example of an embodiment of a multi-cavity wiring board according to the present invention. FIG. 2 is a cross-sectional view of the multi-piece wiring board shown in FIG. [Description of Signs] 1 ... Ceramic mother board 2 ... Wiring board area 2a ... Recess 3 for accommodating electronic components ... Boundary line 4... Through-hole 6 Metallized wiring conductor 7 Metallizing layer 8 for sealing Metallizing layer for external connection

Claims (1)

Claims: 1. A ceramic mother substrate formed by laminating a plurality of insulating layers, each having a concave portion for accommodating an electronic component on an upper surface and a peripheral portion of the concave portion from the bottom surface of the concave portion. Four metallized wiring conductors leading to each corner and a large number of substantially rectangular wiring board regions in which a frame-shaped sealing metallizing layer is adhered on the upper surface surrounding the concave portion are formed vertically and horizontally in an array, and At the intersection of the boundaries dividing each wiring board region, a multi-cavity formed by forming a through hole in which an external connection metallization layer electrically connected to the metallized wiring conductor is formed over the entire inner wall thereof. A wiring board, wherein the metallization layer for sealing in each of the wiring board regions and two of the metallization layers for external connection, which are located diagonally to each of the wiring board regions, are electrically connected to each other; Multiple patterning wiring board, characterized by being.