JP2002158306A - Batch wiring board - Google Patents

Abstract

PROBLEM TO BE SOLVED: To plate the whole wiring conductors with a metal layer for a prescribed thickness. SOLUTION: In this multicavity wiring board, a large number of wiring board regions 2 are arranged and formed in arrays of columns and rows in a central part of a mother board 1 constituted by laminating a plurality of insulating layers 1a, 1b. Each of the wiring board regions 2 has a recessed part 2a for accommodating an electronic component 4, and a plurality of wiring conductors 5 with which electrodes of the electronic component 4 are to be electrically connected on the upper surface side. In the outer peripheral part of the mother board 1, a frame type waste region 3 is formed which has conductor 8 for plating electric continuity with which the respective wiring conductors 5 are electrically connected in common between the insulating layers 1a, 1b. A plurality of dummy recessed parts 3a for exposing the conductor 8 are arranged on the upper surface side of the waste region 3.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a large-sized mother board, which has a large number of wiring board areas, each of which becomes a small-sized wiring board for mounting electronic components such as a semiconductor element and a crystal oscillator. The present invention relates to a multi-cavity wiring board integrally formed and arranged.

[0002]

2. Description of the Related Art Conventionally, a small-sized wiring board used for an electronic component housing package for housing electronic components such as a semiconductor element and a quartz oscillator is, for example, a substantially rectangular board made of ceramics such as an aluminum oxide sintered body. A recess for accommodating an electronic component is formed on the upper surface of a flat insulating substrate, and a plurality of wiring conductors are arranged from the inside of the recess to the lower surface of the insulating substrate. Then, the electronic component is mounted and fixed on the bottom surface of the concave portion of the insulating base, and the electrode of the electronic component is electrically connected to the wiring conductor in the concave portion via an electrical connection means such as a bonding wire or solder. An electronic device as a product by joining a lid made of metal, glass, or the like, or a resin filler made of epoxy resin, etc., so as to cover the recess on the upper surface of the base, and hermetically housing electronic components inside the recess. Becomes

[0003] In recent years, with the recent demand for miniaturization of electronic devices, the size of such a wiring board has become extremely small, on the order of several mm square, and a large number of wiring boards must be handled. In order to facilitate the manufacture of wiring boards and electronic devices, a so-called multi-cavity method is used in which a large number of wiring boards are simultaneously and intensively obtained from a single large-area mother board. It is manufactured in the form of a wiring board.

This multi-cavity wiring board has a concave portion for accommodating electronic components on its upper surface side and a lower surface from the inside of the concave portion in a central portion of a substantially flat mother substrate formed by laminating a plurality of insulating layers. A large number of substantially rectangular wiring board regions having a plurality of wiring conductors are formed vertically and horizontally and integrally arranged, and the outer peripheral portion of the mother board surrounds these wiring board regions so as to form a substantially rectangular frame shape. Formed by abandonment allowance area. Then, for example, after the electronic components are accommodated in the concave portions of the respective wiring board regions, a large number of electronic devices are simultaneously and intensively manufactured by dividing the mother board into the respective wiring board regions.

Generally, in such a multi-cavity wiring board, in order to prevent the wiring conductor from being oxidized and corroded, and to improve the electrical connection between the wiring conductor and the electrode of the electronic component. On the exposed surface of each wiring conductor, 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 applied by an electrolytic plating method.

Conventionally, in such a multi-cavity wiring board, to apply a nickel plating layer or a gold plating layer to each wiring conductor by an electrolytic plating method, the wiring conductors are electrically common inside the throwaway area. And a terminal conductor to which the plating conductor is electrically connected is provided on the outer peripheral side surface of the throw-away area, and the multi-cavity wiring board is provided. Is applied to the exposed surface of each wiring conductor by immersing the wiring conductor in an electrolytic plating solution and supplying a charge for electrolytic plating to each wiring conductor from a terminal conductor via a plating conduction conductor. Was.

[0007]

However, according to this multi-cavity wiring board, when it is immersed in an electrolytic plating solution to supply electric charges for electrolytic plating to the wiring conductors in each wiring board area, the electric field in the electric field is reduced. Lines of electric force are likely to be largely concentrated on the wiring conductors in the wiring board region arranged on the outermost periphery, and in the wiring board region arranged on the outermost periphery, the upper surface of the abandonment allowance region adjacent thereto is flat because The plating solution flows more easily than the other wiring board areas, so that a new plating metal source is easily supplied. An extremely thick plating metal layer is deposited as compared with the conductor, and as a result, the thickness variation of the plating metal layer deposited on the wiring conductor in each wiring board area becomes large, and The plated metal layer of a certain thickness on the wire conductor of had the problem that it is difficult to deposit.

The present invention has been devised in view of such a conventional problem, and an object of the present invention is to reduce variations in the thickness of a plating metal layer applied to a wiring conductor in each wiring board region. It is an object of the present invention to provide a multi-cavity wiring board in which a plating metal layer having a predetermined thickness can be applied to wiring conductors in all wiring board regions by electrolytic plating.

[0009]

A multi-cavity wiring board according to the present invention has a concave portion for accommodating an electronic component on an upper surface side of a mother substrate formed by laminating a plurality of insulating layers. A large number of wiring board regions having a plurality of wiring conductors to which the electrodes of the component are electrically connected are formed in rows and columns, and the wiring conductors are electrically connected in common to the outer periphery of the mother board. A multi-cavity wiring board formed by forming a frame-shaped discard margin area having a plated conductor for conduction between insulating layers, and a plurality of dummy recesses that expose the plating conductor on the upper surface side of the discard margin area. It is characterized by having been provided.

According to the multi-cavity wiring board of the present invention, since a plurality of dummy recesses for exposing the conductor for plating conduction are provided on the upper surface side of the disposal margin area formed on the outer peripheral portion of the mother board, When the individual wiring board is immersed in the electrolytic plating solution and a charge is supplied to the wiring conductor in each wiring board area through the conductor for plating conduction, the lines of electric force in the electric field are:
It is largely concentrated on the plating conduction conductor exposed in the dummy recess located on the outer peripheral side of each wiring board area, and is substantially evenly distributed to the wiring conductors of each wiring board area formed in the center portion of the mother board. . In addition, since the resistance to the flow of the plating solution in the discarding allowance region is increased by the dummy concave portions, the flow of the plating solution in the wiring substrate region arranged on the outermost periphery and the other wiring substrate regions becomes substantially uniform.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, 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-piece wiring board of the present invention, and FIG. 2 is a sectional view of the multi-piece wiring board shown in FIG. In the figure, 1 is a mother board, 2 is a wiring board area, and 3 is a throwaway area.

The mother substrate 1 is made of, for example, an aluminum oxide sintered body, an aluminum nitride sintered body, a mullite sintered body,
2 consisting of ceramic materials such as glass-ceramics
A substantially rectangular flat plate formed by laminating a plurality of insulating layers 1a and 1b, a large number of wiring board regions 2 arranged vertically and horizontally in the center, and these wiring board regions 2 are surrounded on the outer periphery. It is composed of the substantially rectangular frame-shaped discard margin area 3 formed as described above. A plurality of through holes 1c are formed corresponding to the corners of each wiring board region 2, and two pairs of cutouts 1d are formed on opposing outer peripheral side surfaces.

Such a mother substrate 1 is manufactured by a ceramic green sheet laminating method. More specifically, ceramic green sheets for the insulating layers 1a and 1b are prepared, and the ceramic green sheets are appropriately punched. It is manufactured by laminating after processing and firing it at high temperature.

Each of the wiring board regions 2 arranged in the center of the mother board 1 is a region to be a small wiring board, and has a substantially square shape for accommodating the electronic component 4 in the center of each upper surface. It has a concave portion 2a, and has a wiring conductor 5 made of metal powder of metal such as tungsten, molybdenum, copper, silver, etc. from the bottom surface of the concave portion 2a to the lower surface via the through hole 1c. An electronic component 4 such as a semiconductor element or a quartz oscillator is accommodated in the recess 2a, and each electrode of the electronic component 4 is connected to the wiring conductor 5 by an electrical connection means such as a bonding wire 6 or a solder bump. Are electrically connected to each other, and thereafter, each wiring board region 2
The electronic component 4 is sealed by joining a lid or a resin filler (not shown) so as to cover the electronic component 4. The recess 2a is formed by punching a substantially rectangular through hole for the recess 2a in the ceramic green sheet for the insulating layer 1b.
Is formed by printing and applying a metallized paste for the wiring conductor 5 in a predetermined pattern on a ceramic green sheet for the insulating layer 1a.

Further, on the upper and lower surfaces of the mother substrate 1, there are formed vertical and horizontal dividing grooves 7 for dividing the respective wiring board regions 2. After the electronic components 4 are accommodated in the recesses 2a of the respective wiring board regions 2, By dividing the mother board 1 along the dividing grooves 7,
Many electronic devices are manufactured simultaneously and intensively. Division groove 7
Has a substantially V-shaped cross-section and varies depending on the thickness and material of the mother substrate 1, but has a depth of about 0.05 to 1.5 mm and an opening width of about 0.01 to 0.3 mm. Such a dividing groove 7 is formed by laminating ceramic green sheets for the insulating layers 1a and 1b, and then cutting the upper and lower surfaces of the laminated body with a cutter blade or a mold.

The discard margin area 3 formed on the outer peripheral portion of the motherboard 1 is an area for facilitating processing and handling of the motherboard 1. Further, between the insulating layers 1a and 1b, there is formed a substantially square frame-shaped plating conducting conductor 8 to which the wiring conductors 5 of the respective wiring board regions 2 are electrically connected in common. In the notch 1d, a terminal conductor 9 to which the plating conducting conductor 8 is electrically connected is attached.

The plating conductor 8 and the terminal conductor 9 are made of metal powder of metal such as tungsten, molybdenum, silver, or copper.
Functions as a supply path for supplying electric charges for electrolytic plating to the substrate. Then, by immersing the mother board 1 in the electrolytic plating solution and supplying electric charges for electrolytic plating from the terminal conductors 9 to the wiring conductors 5 of the respective wiring board areas 2 via the plating conducting conductors 8, each wiring A plating metal layer such as a nickel plating layer or a gold plating layer is applied to the exposed surface of the wiring conductor 5 in the substrate region 2. Such a conductor 8 for plating conduction and a terminal conductor 9 are obtained by printing and applying a metallized paste for the conductor 8 for plating conduction and the terminal electrode 9 in a predetermined pattern on ceramic green sheets for the insulating layers 1a and 1b. It is formed.

Further, on the upper surface of the throw-away area 3, a plurality of substantially rectangular dummy recesses 3a for exposing the plating conducting conductors 8 are provided so as to correspond to both ends of the arrangement of the wiring board area 2, respectively. ing. These dummy recesses 3
a is for depositing a plating metal layer having a substantially uniform thickness on the wiring conductor 5 in each wiring board region 2;
Is immersed in the electrolytic plating solution, and a charge for electrolytic plating is supplied from the terminal conductor 9 to the wiring conductor 5 of each wiring board region 2 via the plating conducting conductor 8 so that the wiring conductor 5 of each wiring board region 2 is provided. When the plating metal layer is applied to the substrate, the lines of electric force in the electric field were exposed in the dummy recesses 3a by exposing the plating conducting conductors 8 located on the outer peripheral side of the wiring conductors 5 in the respective wiring board regions 2. The lines of electric force are substantially uniformly dispersed in the wiring conductors 5 of the respective wiring board regions 2 by substantially concentrating on the plating conducting conductors 8, and the plating solution on the upper surface side of the throw-away area 3 is formed by the unevenness due to the dummy recesses 3 a. The flow resistance of the plating solution in the wiring board area 2 arranged on the outermost periphery and the other wiring board areas 2 is made substantially uniform by increasing the resistance to the flow of the plating solution. It is possible to apply a plating metal layer having a substantially uniform thickness to the wiring conductor 5 in the wiring board region 2.

The area of the conductive conductor 8 exposed in each of the dummy recesses 3a is preferably in the range of 20 to 200% of the area to be plated on the upper surface side of each wiring board region 2. Plating conduction conductor 8 exposed in each dummy recess 3a
Is less than 20% of the area to be plated on the upper surface side of each wiring board region 2, the lines of electric force in the electric field are dummy when the plating metal layer is applied to the wiring conductor 5 by the electrolytic plating method. It is not possible to satisfactorily concentrate on the plating conduction conductors 8 exposed in the recesses 3a, so that it becomes difficult to apply a plating metal layer having a substantially uniform thickness to the wiring conductors 5 in each wiring board region 2. On the other hand, if it exceeds 200%, a large amount of an unnecessary plating metal layer is deposited on the plating conducting conductor 8 exposed in the dummy recess 3a, and the plating efficiency is reduced.

Such a dummy recess 3a is formed in the insulating layer 1b.
It is formed by punching a through hole for the dummy concave portion 3a in a ceramic green sheet. In addition,
Since the dummy recesses 3a are formed at both ends of each row of the wiring board region 2 in this manner,
Each of the wiring board regions 2 is formed on the laminate of the ceramic green sheets for the insulating layers 1a and 1b by using a cutter blade, a press die, or the like.
When forming the cuts for the dividing grooves 7 for separating the grooves, the dividing grooves 7 formed between the outermost wiring board region 2 and the disposal margin region 3 are almost equally opened on both sides, and as a result, Division groove 7 formed between wiring substrate area 2 and waste allowance area 3
Can effectively be prevented from adhering.

Thus, according to the multi-cavity wiring board of the present invention, the mother board 1 is immersed in the electrolytic plating solution for nickel plating or gold plating, and the mother board 1 is immersed in the plating conductor 8 from the terminal conductor 9. By supplying charges for electrolytic plating to the wiring conductors 5 in each wiring board region 2, a plating metal layer by electrolytic plating is applied to the wiring conductors 5 in each wiring board region 2 to a substantially uniform thickness. The electronic component 4 is mounted and fixed in the concave portion 2a of each wiring board region 2, and the electrodes of the electronic component 4 and the wiring conductors 5 are connected via electrical connection means such as bonding wires 6 and solder. By joining a lid made of metal or ceramics or a resin filler made of epoxy resin or the like onto each wiring board area 2 and dividing the mother board 1 along the dividing grooves 7, a large number of Electronic devices are manufactured simultaneously and intensively.

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 mother substrate 1 has two insulating layers 1a and 1a.
Although the base substrate 1 is formed by stacking the layers b, the mother substrate 1 may be formed by stacking three or more insulating layers.

In the above embodiment, the dummy recess 3a is formed to have substantially the same size as the recess 2a. However, the dummy recess 3a may have a different size from the recess 2a. In this case, it is preferable that the width, length, and depth of the dummy recess 3a be 20% or more of the width, length, and depth of the recess 2a, respectively. Dummy recess 3a
Is less than 20% of the width, length, and depth of the concave portion 2a, respectively, it is difficult to appropriately increase the resistance to the flow of the plating solution in the waste allowance region 3.

In the above-described embodiment, the dummy recesses 3a are provided one by one at both ends of each row of the wiring board region 2. However, the dummy recesses 3a are not necessarily provided in the wiring board region 2. It is not necessary to provide one at each end of each row.

[0026]

According to the multi-cavity wiring board of the present invention,
Since a plurality of dummy recesses for exposing the conductor for plating conduction are provided on the upper surface side of the disposal allowance area formed on the outer peripheral portion of the mother board, the multi-piece wiring board is immersed in the electrolytic plating solution and each wiring is formed. When electric charges are supplied to the wiring conductor in the substrate area via the conductor for plating conduction, the lines of electric force in the electric field are largely concentrated on the conductor for plating conduction exposed in the dummy recess located on the outer peripheral side of each wiring board area. Thus, the wiring conductors in the respective wiring board regions formed in the center portion of the mother board are substantially uniformly distributed. In addition, since the resistance to the flow of the plating solution in the discarding allowance region is increased by the dummy concave portions, the flow of the plating solution in the wiring substrate region arranged on the outermost periphery and the other wiring substrate regions becomes substantially uniform. Therefore, a plating metal layer having a predetermined thickness with a small thickness variation can be applied to the wiring conductor in each wiring board region.

[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 sectional view of the multi-piece wiring board shown in FIG. 1 taken along line AA.

[Explanation of symbols]

 1... Mother board 2... Wiring board area 2a... Recesses for accommodating electronic components 3. ···································································· Conductor for plating conduction

Claims (1)

[Claims] 1. A central portion of a mother substrate formed by laminating a plurality of insulating layers, a concave portion for accommodating an electronic component on an upper surface side, and a plurality of wirings to which electrodes of the electronic component are electrically connected. A large number of wiring board regions having conductors are formed vertically and horizontally in an array, and a frame-like conductor having a plating conduction conductor to which each of the wiring conductors is electrically connected in common is provided on the outer peripheral portion of the mother board. A multi-cavity wiring board formed by forming a discarding allowance area, wherein a plurality of dummy recesses are provided on an upper surface side of the discarding allowance area to expose the plating conducting conductor. substrate.