JP2005285866A - Multiple wiring board - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a multiple wiring board capable of manufacturing a plurality of wiring boards arranged longitudinally and laterally excellent in electrical connection reliability without generating any crack etc. upon division capable of preventing inconvenience such as warping from happening in a thinned wide area ceramic master substrate. <P>SOLUTION: The multiple wiring board comprises a square-shaped master board 1 where a plurality of wiring board regions 2 are arranged longitudinally and laterally at the center of a principal surface into a square shape as a whole, and a frame-shaped margin region 4 is formed on an outer peripheral part; wiring conductors 3 formed on the respective wiring board regions 2; dividing grooves 5' formed at boundaries 5 of the wiring board regions 2; through conductors 11 formed on extension lines of the dividing grooves 5' of the margin region 4; and an outer peripheral metalized layer 6 formed over the entire periphery alternately on upper and lower surfaces of the margin region 4 for coupling the adjacent through conductors 11. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  In the present invention, a large number of wiring board regions, each of which is a small wiring board for mounting electronic components such as a semiconductor element and a crystal resonator, are arranged in a central portion of a large-area mother board in a vertical and horizontal arrangement. This relates to a multi-piece wiring board.

  Conventionally, for example, a small wiring board used for an electronic component storage package for storing an electronic component such as a semiconductor element or a crystal resonator is made of a ceramic material such as an aluminum oxide sintered body, and has a wiring conductor on the surface. In this structure, a plurality of formed rectangular flat ceramic insulating layers are stacked one above the other. An electronic device is formed by housing an electronic component on the wiring board and electrically connecting the electrode of the electronic component to an exposed portion of the wiring conductor via solder, a bonding wire, or the like.

  By the way, with the recent demand for miniaturization of electronic devices, the size of such wiring boards has become extremely small, about several mm square, and it is easy to handle a large number of wiring boards. Therefore, in order to efficiently manufacture a wiring board and an electronic device, a so-called multi-cavity wiring board is obtained which simultaneously obtains a large number of wiring boards from one large-area mother board. It is manufactured in the form.

  An example of such a multi-piece wiring board is shown in FIGS. Here, FIG. 2A is a plan view of a multi-piece wiring substrate, and FIG. 2B is a cross-sectional view taken along B-B ′.

  In the figure, a multi-piece wiring board includes a rectangular mother board 31 in which a plurality of rectangular wiring board regions 32 are arranged in rows and columns and a frame-shaped discard margin region 34 is formed on the outer periphery, and In this structure, a wiring conductor 33 formed in the wiring board region 32 and a dividing groove 35 ′ formed in a boundary 35 of the wiring board region 32 are provided.

  On the upper surface of each wiring board region 32, a mounting portion 42 is formed which is a recess for mounting and housing electronic components. The wiring conductor 33 is partially mounted on the upper surface of the wiring board region 32. Alternatively, it is formed so that it is exposed to the periphery and the other part is exposed to the lower surface and side surfaces of the wiring board region 32.

  Then, an electronic component (not shown) is mounted and fixed on the mounting portion 42 of the wiring board region 32, and the electrodes of the electronic component are exposed to the mounting portion 42 or its periphery through an electrical connection means such as a bonding wire or solder. It is electrically connected to the wiring conductor 33, and a lid made of metal, glass or the like is joined to the upper surface of the wiring board region 32 so as to close the mounting portion 42, or the mounting portion 42 is made of epoxy resin or the like. By filling the resin filler, the electronic parts are housed in the mounting portion 42 in an airtight manner, so that a large number of electronic devices are formed in a multi-piece state in which the horizontal and vertical arrangements are formed. Thereafter, the electronic device in the multi-cavity state is divided into individual wiring board regions 32 to form an electronic device as a large number of products. The electronic component may be mounted on the wiring board region 32 after the multi-piece wiring board is divided into the individual wiring board regions 32.

  In this case, the wiring conductor 33 has a plating layer (not shown) made of nickel, gold or the like applied in advance to the exposed surface. If the plating layer is applied to the wiring conductor 33, the wiring conductor 33 can be effectively prevented from being oxidized, and the bonding wire bonding property to the wiring conductor 33 and the characteristics such as solder wettability are improved. Can be made.

  In order to plate the wiring conductor 33, a multi-piece wiring board is immersed in a plating solution such as nickel or gold, and a predetermined plating current is supplied to the wiring conductor 33. A plating conduction pattern 38 is formed on a pair of sides of the mother board 31 so as to be electrically connected to the wiring conductor 33, and a conduction terminal (on a plating jig (rack)) is provided. (Not shown) is brought into contact with the plating conduction pattern 38, and the plating conduction pattern 38 is sandwiched from above and below by a pair of ends of the conduction terminal, whereby the conduction terminal and the plating conduction pattern 38 are connected from the power source. Thus, a current for plating is supplied to the wiring conductor 33.

  As shown in FIG. 2, the plating conduction pattern 38 is formed by depositing a conductor layer such as a metallized layer on the inner surface of the elliptical arc-shaped or arc-shaped cutout 39 formed on the pair of end surfaces of the mother substrate 31. It is formed by doing.

  In this case, in general, in the electroplating method, the closer to the outer peripheral portion of the portion to be plated, the easier the current flows, the higher the current density, and the easier the circulating supply of the plating solution. It is known that the plating thickness increases.

  Therefore, in order to make the thickness of the plating such as nickel or gold deposited on the wiring conductor 33 in the wiring board region 32 uniform, the main surface (usually an electronic component) A frame-like outer peripheral metallized layer 36 is formed on the plating main conduction pattern 38 and the wiring conductor 33 on the upper main surface).

  The outer peripheral metallized layer 36 is a so-called auxiliary cathode in which a plating metal such as nickel or gold to be deposited on the inner portion to be plated is deposited on itself to suppress variation in the plating thickness of the portion to be plated. And prevents variations in the thickness of the plating applied to the wiring conductor 33 in the inner wiring board region 32.

A via conductor 40 is formed on the boundary 35 of the adjacent wiring board region 32, and the via conductor 40 electrically connects the wiring layers of the adjacent wiring board region 32 and the upper and lower wiring layers. Thus, when divided into individual wiring board regions 32, they are divided vertically so that side conductors (castellation conductors) located on the side faces of the wiring board are obtained.
JP 2000-340898 A

  However, in recent years, small wiring boards used for electronic component storage packages and the like have been required to be further reduced in size, particularly reduced in thickness due to demands for downsizing and low profile of electronic devices. In response to this, the mother board 31 has become very thin, for example, with a thickness of 0.5 mm or less.

  When the mother substrate 31 is thinned in this way, one of the upper surface of the mother substrate 31 and the like is caused by the difference in shrinkage rate during firing between the metal paste that becomes the outer metallized layer 36 and the ceramic green sheet that becomes the mother substrate 31. A large stress over the entire length of each side acts in one direction on each side of the outer peripheral portion of the main surface, and the mother substrate 31 is warped in a concave or convex shape due to this stress, and each wiring board region 32 is separated into individual pieces. When dividing into two, the boundary lines between the respective wiring board regions 32 and between the wiring board region 32 and the disposal margin region 34 are distorted, so that cracks and burrs are generated in the individual wiring boards. It was.

  The present invention has been devised in view of such a problem, and the object thereof is the main surface of the disposal margin region 34 on the outer periphery of the mother board 31 in the wiring board 32 which has been further miniaturized, particularly thinned. Even if the outer peripheral metallized layer 36 for preventing the variation in the plating thickness is provided, it is possible to prevent problems such as warping in the mother board 31 and to generate cracks and chips when the wiring board regions 32 are divided. An object of the present invention is to provide a multi-piece wiring board that can prevent the occurrence and can adhere a good plating layer to the surface of the wiring conductor 33.

  The multi-cavity wiring board according to the present invention is a square frame in which a plurality of wiring board regions are arranged in a square shape as a whole in the center portion of the main surface, and a frame-shaped discard margin region is formed in the outer peripheral portion. -Shaped mother board, wiring conductors formed in each of the wiring board regions, split grooves formed at the boundaries of the wiring board regions, and through conductors formed on the extension lines of the split grooves in the discard margin region And an outer peripheral metallization layer that connects the adjacent through conductors and is alternately formed on the upper and lower main surfaces of the discard margin region over the entire circumference.

  Further, in the multi-cavity wiring board of the present invention, it is preferable that the outer peripheral metallization layer has the same shape along the side in one side of the entire wiring board region, and is planar. It is characterized by being formed linearly as a whole.

  According to the multi-cavity wiring board of the present invention, a rectangular mother board having a frame-shaped discard margin area formed on the outer periphery, wiring conductors formed in each wiring board area, and the boundary of the wiring board area The formed dividing grooves, the through conductors formed on the extension lines of the dividing grooves in the disposal margin area, and the adjacent through conductors are connected, and the upper and lower main surfaces of the disposal margin area are alternately formed over the entire circumference. Since the outer peripheral metallized layer is provided, even if stress is generated due to the difference in shrinkage rate during firing between the outer peripheral metallized layer and the mother substrate, the stress is disposed on the upper and lower main surfaces of the disposal margin region. Are alternately generated at each part of the outer peripheral metallization layer formed over the entire circumference, and stress cancels out between the upper main surface and the lower main surface. Large in one direction over the entire length of each side of one main surface Never stress acts, it is possible to prevent warping of the mother board. Thereby, cracks and burrs can be prevented from occurring when each wiring board region is divided into individual pieces. In addition, when mounting electronic components such as semiconductor elements without dividing the mother board, mounting accuracy can be prevented from being deteriorated and mounting defects can be prevented.

  Further, since the formed outer peripheral metallization layer acts as a so-called auxiliary cathode, the current flowing through each wiring conductor becomes uniform, and the wiring conductor on the main surface of the wiring board region formed in a plurality of rows and columns on a large area mother board. The thickness of the plating layer deposited on the substrate can be made uniform and stable.

  In addition, since the through conductor is formed on the extension line of the dividing groove in the discard margin region, even if the dividing groove is formed beyond the outer peripheral metallization layer in the discard margin region of the mother board, the outer peripheral metallization layer on the upper and lower main surfaces The thickness of the plating layer that adheres to the wiring conductor by energizing the entire circumference of the outer metallization layer on the upper and lower main surfaces of the mother board without causing any electrical continuity is divided. Can be reliably suppressed, and each wiring board region of the mother board can be efficiently divided into individual pieces.

  Further, for example, the through-conductor formed in the abandon margin region is not the one in which the conductor is completely filled in the through-hole, and the conductor is attached only to the inner wall of the through-hole. Since the plating solution can be smoothly circulated between the front and back surfaces of the mother board through the cavity inside the through conductor even when the size of the wiring becomes larger, the wiring formed in a plurality of rows and columns on a large area of the mother board The thickness of the plating layer deposited on the wiring conductor on the main surface of the substrate region can be made uniform and stable.

  Further, according to the multi-cavity wiring board of the present invention, preferably, the outer peripheral metallized layer has the same shape along the side in one side of the entire wiring board region and is flat. Since it is formed linearly as a whole, it occurs due to the difference in shrinkage rate during firing between the outer peripheral metallized layer and the mother substrate over the entire circumference of each of the upper and lower main surfaces of the mother substrate. Since the stresses are almost equal, it is possible to prevent warping of the mother substrate even more reliably. As a result, it is possible to provide a multi-piece wiring board capable of producing a wiring board having excellent electrical connection reliability.

  Next, a multi-piece wiring board according to the present invention will be described with reference to the accompanying drawings. FIG. 1A is a plan view showing an example of an embodiment of a multi-cavity wiring board according to the present invention, and FIG. 1B is an AA ′ line of the multi-cavity wiring board of FIG. FIG. In the figure, 1 is a mother board, 2 is a wiring board area, 3 is a wiring conductor, 4 is a margin area, 6 is an outer metallization layer, 8 is a pattern for plating conduction, and 11 is a through conductor. Note that the wiring conductors 3 in each wiring board region 2 are actually complicated patterns, but in order to make the drawing easier to see, they are abbreviated as rectangular patterns.

  The mother board 1, the wiring board region 2, the wiring conductor 3, the outer peripheral metallized layer 6, and the through conductor 11 constitute the multi-cavity wiring board of the present invention.

  The mother board 1 is formed by laminating ceramic layers made of a ceramic material such as an aluminum oxide sintered body, an aluminum nitride sintered body, a mullite sintered body, or a glass ceramic, and a plurality of wirings are provided at the center of the main surface. The substrate region 2 is arranged in a square shape as a whole in the vertical and horizontal directions.

  Moreover, each wiring board area | region 2 is the square shape whose length of one side is about 2-20 mm and thickness is about 0.4-2 mm, for example. A mounting portion 12 including a recess for storing and mounting an electronic component is provided at the center of the upper surface of each wiring board region 2.

  In addition, a frame-shaped discard margin region 4 is formed on the outer peripheral portion of the mother board 1. The disposal allowance region 4 is one that facilitates handling of a multi-piece wiring board, and facilitates uniform, stable formation of a plating layer when a plating layer is deposited on the wiring conductor 3 as will be described later. And so on.

  If such a mother substrate 1 is made of, for example, an aluminum oxide sintered body, a plurality of ceramic green sheets prepared by forming a raw material powder such as aluminum oxide into a sheet shape are prepared, and the wiring substrate is partitioned vertically and horizontally. The region 2 and the disposal margin region 4 are provided, and then a part of this ceramic green sheet is subjected to an appropriate punching process, and then laminated and fired.

  A wiring conductor 3 is formed in each wiring board region 2. The wiring conductor 3 is electrically connected to an electrode of an electronic component mounted on the mounting portion via a bonding wire, solder, or the like, and functions as a conductive path that leads to the lower surface or side surface of the wiring board region 2.

  The wiring conductor 3 is made of a metal material such as tungsten, molybdenum, copper, or silver. For example, if the wiring conductor 3 is made of tungsten, a pattern of a predetermined wiring conductor 3 is formed on a ceramic green sheet that becomes the base substrate 1 using a tungsten metal paste. It is formed by printing and printing together with a ceramic green sheet.

  Further, the mother substrate 1 has a dividing groove 5 ′ formed on the main surface (upper surface in the example of FIG. 1) along the boundary 5 of the wiring substrate region 2.

  The division grooves 5 ′ are for facilitating the division work when dividing the mother board 1 into the respective wiring board regions 2. By bending the mother substrate 1 around the dividing groove 5 ′, the mother substrate 1 is broken from the bottom surface of the dividing groove 5 ′ to the main surface of the opposing mother substrate 1 (the lower surface in the example of FIG. 1). Done. The dividing grooves 5 ′ may be formed on the upper and lower main surfaces of the mother substrate 1. Moreover, it is desirable to form also in the part along the boundary 5 of the wiring board area | region 2 and the discard margin area | region 4. FIG.

  Such a dividing groove 5 ′ is cut at a predetermined depth by pressing a metal blade along the boundary 5 of the wiring board region 2, for example, on the main surface of the laminate of ceramic green sheets to be the mother board 1. It is formed by inserting.

  Then, an electronic component (not shown) is mounted and fixed on the mounting portion of the wiring board region 2 and the electrodes of the electronic component are exposed to the mounting portion or its periphery via an electrical connection means such as a bonding wire or solder. Electrically connected to the wiring conductor 3, a lid made of metal, glass or the like is bonded to the upper surface of the wiring board region 2 so as to close the mounting portion, or a resin filler made of epoxy resin or the like is placed in the mounting portion. By filling, the electronic components are housed in the mounting portion in an airtight manner, so that a large number of electronic devices are formed in a multi-piece state in which the electronic devices are arranged vertically and horizontally. Thereafter, the electronic device in the multi-cavity state is divided into individual wiring board regions 2 to form an electronic device as a large number of products. The mounting of electronic components on the wiring board region 2 may be performed after the multi-piece wiring board is divided into individual wiring board regions 2.

  In this case, in order to prevent oxidation corrosion on the exposed surface of the wiring conductor 3 and improve characteristics such as solder wettability and bonding wire bonding property when connecting the solder or bonding wire, A plating layer (not shown) such as gold is previously applied.

  In order to plate the wiring conductor 3, a multi-piece wiring board is immersed in a plating solution such as nickel or gold, and a predetermined plating current is supplied to the wiring conductor 3. A plating conduction pattern 8 is formed on a pair of sides of the mother board 1 so as to be electrically connected to the wiring conductor 3, and a conduction terminal (rack) provided on a plating jig (rack). (Not shown) is brought into contact with the plating conduction pattern 8, and the plating conduction pattern 8 is sandwiched from above and below by a pair of ends of the conduction terminal, whereby the conduction terminal and the plating conduction pattern 8 are connected from the power source. Thus, a current for plating is supplied to the wiring conductor 3.

  In this case, via conductors 10 may be formed between the wiring board regions 2 or between the wiring board region 2 and the outer peripheral metallized layer 6 to facilitate electrical connection therebetween.

  The via conductor 10 is formed by forming a through hole in the ceramic green sheet to be the mother substrate 1 and printing or filling or filling a metal paste similar to that for forming the wiring conductor 3 inside or inside the through hole. It is formed.

  The outer peripheral metallized layer 6 is for reducing and uniforming the plating layer deposited on the wiring conductor 3. In other words, the outer peripheral metallized layer 6 functions as a so-called auxiliary cathode, whereby the plating thickness deposited on the wiring conductor 3 in the inner wiring board region 2 is increased at the outer peripheral portion, and the thickness of the plating layer varies. It is prevented from occurring.

  The outer peripheral metallized layer 6 is preferably formed with a width of 2 mm or more in order to prevent variations in the plating thickness of the wiring conductor 3.

  The outer peripheral metallization layer 6 is formed by applying a metal paste similar to that for forming the wiring conductor 3 in a desired shape on the main surface of the disposal margin region 4 on the outer periphery of the ceramic green sheet. It is formed by simultaneous firing. The outer peripheral metallized layer 6 is preferably formed of the same material as the wiring conductor 3 in consideration of productivity and the like.

  In the multi-cavity wiring board of the present invention, the outer peripheral metallized layer 6 connects adjacent ones of the through conductors 11 formed on the extension line of the dividing groove 5 ′ of the discard margin region 4 and also discards margin region. The four upper and lower main surfaces are alternately formed over the entire circumference.

  With this configuration, even if stress is generated between the outer peripheral metallized layer 6 and the mother substrate 1 due to the difference in shrinkage rate during firing, the stress is alternately alternately applied to the upper and lower main surfaces of the disposal margin region 4 over the entire periphery. One of the main surfaces of the mother substrate 1 is generated intermittently for each part of the outer peripheral metallized layer 6 formed over the entire surface and the stress cancels out between the upper main surface and the lower main surface. A large stress does not act in one direction over the entire length of each side of the substrate, and the warp of the mother substrate 1 can be prevented. As a result, it is possible to prevent cracks and burrs from occurring when each wiring board region 2 is divided into individual pieces.

  In addition, when mounting electronic components such as semiconductor elements without dividing the mother board 1, mounting accuracy can be prevented from being deteriorated and mounting defects can be prevented.

  Further, since the formed outer peripheral metallization layer 6 functions as a so-called auxiliary cathode, the current flowing through each wiring conductor 3 becomes uniform, and the main part of the wiring board region 2 formed in a plurality of rows and columns on the mother board 1 having a large area. The thickness of the plating layer applied to the wiring conductor 3 on the surface can be made uniform and stable.

  The through conductors 11 are for electrically connecting the outer peripheral metallized layers 6 on the upper and lower main surfaces of the mother board 1 to form one frame-like conductor as a whole. By forming the outer peripheral metallized layer 6 as a single frame-shaped conductor between the upper and lower main surfaces of the mother substrate 1, it is possible to reliably function as a frame-shaped auxiliary cathode that surrounds the entire wiring substrate region 2. The thickness of the plating layer deposited on the substrate can be made uniform and stable.

  In this case, as a method of forming the through conductor 11, for example, a plurality of ceramic green sheets are prepared, and a predetermined position is formed by a mold or the like in order to form the through conductor 11 formed in the mounting portion and the disposal margin region 4. After performing the punching process, the conductive paste is applied to the inner wall of the through hole of the punched ceramic green sheet by a screen printing method or the like, and the ceramic green sheet in which the metallized layer is applied to the inner wall of the through hole; It can be produced by laminating a ceramic green sheet on which a conductive paste is printed at a predetermined position, and firing it by closely contacting it.

  As described above, the through-conductor 11 does not have the conductor completely filled in the through-hole, and the conductor is attached only to the inner wall of the through-hole. In addition, since it is possible to smoothly circulate the plating solution between the front and back surfaces of the mother board 1 through the cavity inside the through conductor 11, a plurality of wiring board regions arranged vertically and horizontally on the large area mother board 1 are provided. The thickness of the plating layer deposited on the wiring conductor 3 on the main surface 2 can be made uniform and stable.

  Here, it is preferable that the outer peripheral metallized layer 6 formed alternately on the upper and lower main surfaces of the disposal margin region 4 over the entire circumference has a width of about 2 to 5 mm. When the width of the outer peripheral metallized layer 6 is less than 2 mm, the function as an auxiliary electrode is likely to be reduced, and the thickness of the wiring conductor 3 in the wiring board region 2 is likely to vary. In addition, the size of the through conductor 11 for electrically connecting the outer peripheral metallized layer 6 alternately to the upper and lower main surfaces of the disposal margin region 4 over the entire circumference is reduced, and the front and back surfaces of the mother board 1 are interposed via the through conductor 11 The plating solution may be prevented from circulating, and the thickness of the plating layer deposited on the wiring conductor 3 on the main surface of the wiring board region 2 may become unstable.

  Further, if the width of the outer peripheral metallization layer 6 exceeds 5 mm, the number of wiring board regions 2 formed on the mother substrate 1 is reduced, resulting in poor productivity, and the outer metallization layer 6 acting as an auxiliary cathode has a plating component. Since (nickel, gold, etc.) is deposited and consumed, the life of the plating solution tends to be shortened.

  Further, in the multi-piece wiring board of the present invention, the outer peripheral metallized layer 6 has the same shape in one side part of the whole wiring board region 2 along the side part, and the whole in a plan view. It is preferable that it is formed linearly.

  As a result, the stress generated due to the difference in shrinkage rate during firing between the outer peripheral metallized layer 6 and the mother substrate 1 over the entire circumference of each of the upper and lower main surfaces of the mother substrate 1 becomes substantially equal. It is possible to reliably prevent the mother substrate 1 from warping.

  In this case, it is desirable that the outer peripheral metallized layer 6 is formed so as to have a thickness of 5 to 20 μm on the entire circumference of the upper and lower main surfaces of the disposal margin region 4. When the thickness of the outer peripheral metallized layer 6 is less than 5 μm, the connection thickness with each through conductor 11 becomes thin, and the electrical connectivity may be deteriorated. Further, if the thickness of the outer peripheral metallized layer 6 exceeds 20 μm, the substrate may be locally warped when the thickness of the mother substrate 1 is as thin as 1 mm or less.

  Further, the outer peripheral metallized layer 6 is formed on each side of the main surface (upper surface in the example of FIG. 1) on the side where the mounting portion is formed up to a portion in contact with the corner of the rectangular array of the wiring board region 2. It is preferable to do so.

  This ensures that the plating layer is formed thick on the wiring conductor 3 exposed to the mounting portion at the corners of the square array in which the thickness of the plating layer deposited on the wiring conductor 3 tends to be particularly thick. Since it can prevent more effectively, the reliability of the electrical connection of the electronic component with respect to the exposed part of the wiring conductor 3 can be ensured more highly. If the plating layer deposited on the wiring conductor 3 to which the electrodes of the electronic component are electrically connected via bonding wires, solder, or the like becomes too thick, the internal stress of the plating layer increases, so that during bonding and soldering In combination with this stress, the wiring conductor 3 may be easily peeled off from the mother board 1.

  As a result, it is possible to provide a multi-piece wiring board capable of producing a wiring board excellent in electrical connection reliability.

  It should be noted that the present invention is not limited to the above embodiments, and various modifications may be made without departing from the gist of the present invention. For example, in this example, the mother board 1 is composed of 35 wiring board regions 2 of 7 rows × 5 columns, but it is needless to say that the mother board 1 may be composed of other arrangements of mother boards.

  Further, the through conductor 11 may be formed so as to fill not only the inner wall surface of the through hole formed in the mother board 1 but also the inside of the through hole. In this case, a dummy through hole (not shown) may be formed in the discard margin region 4 in order to ensure a good distribution of the plating solution between the upper and lower main surfaces of the mother substrate 1.

  In the example shown in FIG. 1, the through conductors 11 are formed on the extended lines of all the divided grooves 5 ′. However, the through conductors 11 need not be formed on the extended lines of all the divided grooves 5 ′. Further, it may be formed between the extended lines of the plurality of dividing grooves 5 ′. However, in this case, it is necessary to form the dividing groove 5 ′ so as not to reach the outer peripheral metallized layer 6 in a portion up to the inner side of the outer peripheral metallized layer 6 so as not to divide the outer peripheral metallized layer 6.

(A) is a top view which shows an example of embodiment of the multi-cavity wiring board of this invention, (b) is sectional drawing in the A-A 'line of the multi-cavity wiring board of (a). (A) is a top view which shows an example of embodiment of the conventional multi-cavity wiring board, (b) is sectional drawing in the B-B 'line of the multi-cavity wiring board of (a).

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Mother board 2 ... Wiring board area | region 3 ... Wiring conductor 4 ... Discard allowance area 5 ... Boundary 5 '... Dividing groove 6 ... Outer metallization layer 11 ... Penetration conductor

Claims (2)

A plurality of wiring board regions arranged vertically and horizontally at the center of the main surface as a whole in a square shape, and a rectangular mother board having a frame-shaped discard margin region formed on the outer periphery, and each of the wiring board regions A wiring conductor formed on the wiring board region, a dividing groove formed at a boundary of the wiring board region, a through conductor formed on an extension line of the dividing groove in the discarding region, and the adjacent through conductors are connected to each other. And an outer peripheral metallization layer formed alternately over the entire circumference on the upper and lower main surfaces of the discard margin region. The outer peripheral metallization layer is characterized in that, in one side portion of the entire wiring board region, all of the shapes along the side portion are the same and formed linearly as a whole in plan view. The multi-cavity wiring board according to claim 1.

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