JP4646825B2 - Multiple wiring board - Google Patents

Description

  The present invention provides a multi-piece wiring board in which a plurality of wiring board regions, each of which is a wiring board for accommodating electronic components, are arranged vertically and horizontally in the central portion of the ceramic mother board, and is divided into wiring board regions. The present invention relates to an electronic component storage package separated into individual pieces and an electronic device on which the electronic component is mounted.

  2. Description of the Related Art Conventionally, wiring boards (electronic component storage packages) for mounting electronic components such as semiconductor elements and crystal resonators are made of tungsten on the surface of an insulating base made of an electrically insulating material such as an aluminum oxide sintered body. It is formed by disposing a wiring conductor made of metal powder metallization such as molybdenum.

  An electronic component is mounted on the upper surface of the wiring board, and after each electrode of the electronic component is electrically connected to the wiring conductor via an electrical connection means such as solder or a bonding wire, the electronic component Is covered with a lid made of metal or ceramics or potting resin and hermetically sealed to produce an electronic device.

  By the way, with the recent demand for downsizing of electronic devices, the size of such wiring boards has become extremely small, about several mm square. In order to make such a small wiring board easy to handle and to improve the efficiency of manufacturing a wiring board and an electronic device using the wiring board, a large number of wiring boards that become wiring boards are used. It is manufactured in the form of a so-called multi-cavity wiring board in which the regions are arranged vertically and horizontally in the center of a large-area mother board.

  In the multi-cavity wiring board, for example, a plurality of wiring board regions each provided with a wiring conductor are arranged vertically and horizontally in the central portion of a substantially square plate-like mother board, and each wiring board is formed on at least one surface of the mother board. Dividing grooves that divide the region are formed vertically and horizontally. Then, before or after the electronic components are mounted on each wiring board area, the mother board is bent along the dividing grooves and divided into wiring board areas, so that a large number of wiring boards and electronic devices can be obtained. Are manufactured simultaneously and intensively.

  When a force is applied from the outside when transporting or mounting electronic components on such a multi-piece wiring board, the force is concentrated on the end of the dividing groove, and the corner is used as a starting point. Since a substrate may be carelessly cracked, a method has been proposed in which a hole deeper than the dividing groove is formed at a position overlapping the end of the dividing groove. As a result, when force is applied from the outside when transporting or mounting electronic components on the mother board, the force is well dispersed in the holes, so the mother board is inadvertent starting from the end of the dividing groove It is possible to suppress the occurrence of cracks (see Patent Document 1).

Moreover, such a multi-piece wiring board is performed by, for example, an automatic dividing apparatus as described in Patent Document 2. This automatic dividing device divides the mother board along the dividing groove by transferring the mother board to the holding part by the belt and applying pressure to the dividing groove by the holding plate, the pressing roller and the pressing roller in the holding part. It is. In the division, first, the mother board is divided into strip-shaped mother boards in which the wiring board regions are arranged in a line, and this strip-like mother board is further divided along the dividing grooves into individual wiring boards. It is done by.
JP 2003-273274 A JP 2002-166398 A

  However, in the conventional mother board, inadvertent cracking of the mother board starting from the end of the dividing groove due to an external force at the time of conveyance or the like can be suppressed by the hole, but the mother board is moved along the dividing groove. When the substrate is bent and divided into strip-shaped mother substrates, the outer periphery of the mother substrate may not be divided along the extension lines of the dividing grooves from the holes. In particular, if the portion other than the extension line of the dividing groove on the inner wall of the hole becomes the starting point of the division, the direction of division is greatly deviated from the extension line of the dividing groove, and the outer side of the strip-shaped mother board is the extension of the dividing groove. There was a case where a portion protruding greatly from the line was formed.

  In this way, if there is a protruding part of the outer edge of the strip-shaped mother board rather than a straight line, the strip-shaped mother board is automatically divided by, for example, transferring it in a groove that matches the width of the strip-shaped mother board. When trying to supply to the apparatus, there is a problem that the strip-shaped mother substrate does not enter the groove or is caught on the inner wall of the groove and is supplied obliquely to the dividing apparatus. If the strip-shaped mother board is supplied obliquely to the dividing device, it is impossible to apply a pressure to a predetermined position of the strip-shaped mother board to divide, and individual wiring boards along the dividing grooves Therefore, there is a problem that burrs and chips are likely to occur in each divided wiring board. The same applies to the manual dividing device. If there is a protruding portion on the strip-shaped mother board, it is difficult to align the dividing groove with a predetermined position of the manual dividing device.

  The present invention has been devised in view of the above-mentioned problems of the prior art, and its purpose is to prevent inadvertent cracking of the mother board by the holes formed at the ends of the dividing grooves and to make the mother board a strip. It is an object of the present invention to provide a multi-piece wiring substrate that can be favorably divided along an extended line of a dividing groove when dividing the substrate into a substrate.

  In the multi-cavity wiring board of the present invention, a dividing groove for dividing the mother board into a plurality of regions is formed on a flat mother board, and the width of the dividing groove is wider than that of the dividing groove. A hole deeper than the dividing groove is formed, and a metallized layer is deposited on the inner peripheral surface of the hole so that the mother substrate is exposed at a portion intersecting with the extension line of the dividing groove. It is characterized by being.

  In the multi-piece wiring board of the present invention, it is preferable that the metallized layer is formed continuously between the hole and the outer side of the mother board in a region around the extension line of the dividing groove. It is characterized by being.

  In the multi-piece wiring board of the present invention, it is preferable that a second division groove shallower than the division groove is formed on an extension line of the division groove between the hole and the outer side of the mother board. It is characterized by that.

  The multi-cavity wiring board according to the present invention has an inner peripheral surface of a hole formed by applying a metallized layer on the inner peripheral surface of the hole so that a portion of the mother substrate that intersects with the extension line of the dividing groove is exposed. The portion where the metallized layer is deposited is reinforced, and the portion where the mother substrate is exposed without the metallized layer being deposited is lower in mechanical strength than the portion where the metallized layer is deposited, The exposed part of the mother board becomes the starting point when dividing, and since this starting point is located at the extension line of the dividing groove, the mother board is well formed into a strip-like mother board along the extending line of the dividing groove. It can be divided, the size and shape of the strip-shaped mother board can be improved, and the occurrence of burrs and chips on the wiring board can be suppressed.

  Preferably, the metallization layer is continuously formed between the hole and the outer side of the mother substrate in the peripheral region of the extension line of the division groove, so that the peripheral region on the extension line of the division groove is metallized. Since it is reinforced by the layer, the crack generated from the exposed portion of the inner peripheral surface of the hole as a starting point is likely to progress along the extension line of the dividing groove that is not reinforced by the metallized layer. Can be more favorably divided into strip-shaped mother boards along the extended lines of the dividing grooves, and the occurrence of burrs and chips on the wiring board can be further suppressed.

  Preferably, the second divided groove portion is formed by forming a second divided groove shallower than the divided groove on the extended line of the divided groove between the hole and the outer side of the mother substrate. Since the mechanical strength is relatively weaker than that of the surrounding area, a crack generated starting from a portion where the mother substrate is exposed without the metallized layer being deposited is advanced along the second divided groove. The second divided groove portion has a mechanical strength stronger than that of the divided groove portion. Therefore, when a force is applied from the outside when transporting to the mother board or mounting an electronic component, the second divided groove portion. Since the generation of inadvertent cracks in the mother board from the bottom of the substrate is suppressed, the mother board can be better divided into strip-shaped mother boards along the extension lines of the dividing grooves. The occurrence of chipping can be further suppressed.

  Next, the present invention will be described in detail 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 enlarged plan view of a main part in part A of FIG. 2A is a cross-sectional view taken along line BB ′ of the multi-cavity wiring board in FIG. 1B, and FIG. 2B is a multi-cavity wiring board in FIG. 1B. It is sectional drawing in CC 'line. It is. In these figures, 101 is a mother board, 102 is a dividing groove, 103 is a hole, 104 is a metallized layer, and 105 is a wiring conductor.

  In the multi-cavity wiring board of the present invention, a dividing groove 102 that divides the mother board 101 into a plurality of regions is formed in a flat mother board 101, and the width of the dividing groove 102 is larger than that of the dividing groove 102. The metallization layer 104 is formed so that the mother substrate 101 is exposed on the inner peripheral surface of the hole 103 at a portion where the extension line of the division groove 102 is crossed. It is deposited.

  The base substrate 101 is an electrically insulating ceramic material such as an aluminum oxide sintered body, a mullite sintered body, an aluminum nitride sintered body, a silicon carbide sintered body, a silicon nitride sintered body, or a glass ceramic. It functions as a base material for manufacturing a large number of small wiring boards simultaneously. Then, electronic components (not shown) such as semiconductor elements, resistors, and capacitors are mounted on the upper surface of each small wiring board.

  If the mother substrate 101 is made of, for example, an aluminum oxide sintered body, an organic binder, solvent, plasticizer, and dispersing agent suitable for ceramic raw material powders such as aluminum oxide, silicon oxide, magnesium oxide, and calcium oxide. The ceramic slurry obtained by adding and mixing, etc. is formed into a sheet shape by using a conventionally known sheet forming method such as a doctor blade method, and then a ceramic green sheet is obtained. It is manufactured by laminating a plurality of sheets and baking them at a high temperature (about 1500 to 1800 ° C.).

  The mother board 101 has a plurality of divided grooves 102 formed in a lattice pattern on the upper surface of the mother board 101 so as to divide the mother board 101 into a plurality of regions. 105 is deposited.

  The wiring conductor 105 functions as a conductive path for electrically connecting an electronic component mounted on a small wiring board to an external electric circuit board, and is made of metal powder metallization such as tungsten, molybdenum, copper, silver, and the like. The metallized paste for the wiring conductor 105 is printed on the ceramic green sheet for the substrate 101 by printing means such as a screen printing method, and is fired together with the ceramic green sheet for the mother substrate 101 to adhere to the upper and lower surfaces of each region. It is formed. The metallized paste is prepared by adding an organic binder, an organic solvent, and a dispersant as required to the main component metal powder, and mixing and kneading them by a kneading means such as a ball mill, a three-roll mill, or a planetary mixer. Glass or ceramic powder may be added to match the sintering behavior of the ceramic green sheet or to increase the bonding strength with the mother substrate after firing.

  Further, the wiring conductors 105 formed on the upper surface and the lower surface are electrically connected by a through conductor penetrating the mother board 101. Such penetrating conductors are used for penetrating conductors by a punching method using a die or punching or a processing method such as laser processing on a ceramic green sheet for the mother substrate 101 prior to the printing and application of the metallized paste for forming the wiring conductor 105. The through hole for the through conductor is filled with the metallized paste for the through conductor by a printing means such as a screen printing method and fired together with the ceramic green sheet for the mother substrate 101. Formed in each region. The metallized paste for the through conductor is prepared in the same manner as the metallized paste for the wiring conductor 105, but is prepared to have a viscosity suitable for filling depending on the amount of the organic binder or organic solvent.

  Divided grooves 102 formed on the upper surface of the mother board 101 divide the mother board 101 into a plurality of regions having a size corresponding to the shape of a desired small wiring board, and bend the mother board 101 to obtain a plurality of pieces. When forming a small wiring board, the opening is formed so as to make the bending easy and accurate, and both ends thereof are separated from the outer periphery of the mother board 1, and appear on the surface of the mother board 101. The width is about 0.05 to 1 mm, and the depth is about 0.05 to 2 mm. Such dividing grooves 2 are formed on the upper surface of the mother board 101 by pressing a cutter blade or a die having a V-shaped cutting edge against a ceramic green sheet for the mother board 101 to make a cut. It is formed in a shape. When the mother substrate 101 is produced by laminating a plurality of ceramic green sheets, the cut is made after producing a laminated body in which a plurality of ceramic green sheets are laminated.

  The hole 103 is formed at the end of the dividing groove 102 as being wider than the dividing groove 102 and deeper than the dividing groove 102. Since the hole 103 is formed wider than the end of the dividing groove 102 and deeper than the dividing groove 102, stress is applied when external stress is applied to the mother board 101 during transportation or mounting of electronic components. Can be satisfactorily dispersed in the holes 103, and acts as a means for suppressing the occurrence of inadvertent cracks starting from the ends of the dividing grooves 102.

  Such holes 103 are formed in some of the ceramic green sheets for the mother substrate 101 by forming through holes for the holes 103 by a die or punching method by punching or laser processing or the like, and communicate with the holes 103. In this way, by forming a cut for the dividing groove 102 in the ceramic green sheet for the mother substrate 101, it is formed at the end of the dividing groove 102.

  The hole 103 may penetrate the mother substrate 101 or may not penetrate the mother substrate 101. Further, the hole 103 may be formed in a circular shape, a polygonal shape such as a square shape or a triangular shape, and may have a shape other than the above. The hole 103 is preferably circular, and when an external stress is applied to the mother board 101 during transportation or mounting of electronic components, the stress can be well dispersed in the hole, which is inadvertent It becomes possible to effectively suppress cracking. Further, in the case where the shape of the hole 103 is a polygonal shape such as a polygon, if the corner and the divided groove 102 intersect, a stress is applied to the end of the divided groove 102 when external stress is applied. Therefore, it is preferable that the corners of the holes 103 do not intersect with the dividing grooves 102.

  In the present invention, the metallized layer 104 is deposited so that the mother substrate 101 is exposed at the portion of the inner peripheral surface of the hole 103 that intersects with the extension line of the dividing groove 102. With this configuration, the portion where the metallized layer 104 is deposited on the inner peripheral surface of the hole 103 is reinforced, and the portion where the mother substrate 101 is exposed without the metallized layer 104 being deposited is covered with the metallized layer 104. The mechanical strength is lower than that of the formed part, and the exposed part becomes a starting point when dividing, and since this starting point is located at an extension line of the dividing groove 102, the mother substrate 101 is separated from the dividing groove. It can be divided into strip-shaped mother boards well along the extension line, the dimensions and shape of the strip-shaped mother board can be made good, and the occurrence of burrs and chips on the wiring board can be suppressed. .

  The metallized layer 104 is made of metal powder metallized such as tungsten, molybdenum, copper, or silver, and is formed on the inner peripheral surface of the hole 103 of the ceramic green sheet for the mother substrate 101 using a printing means such as a screen printing method. The metallized paste for the metallized layer 104 can be formed on the inner peripheral surface of the hole 103 by printing. Then, when the metallized paste for the metallized layer 104 is printed on the inner peripheral surface of the hole 103, an opening such as a screen printing mask is formed only in a portion that does not intersect with the extension line of the dividing groove 102. The metallized paste for the metallized layer 104 is masked by applying an adhesive tape or the like to the portion that intersects with the extended line of the inner peripheral surface of the hole 103 and masking. The metallized layer 104 may be deposited on the inner peripheral surface of the hole 103 so that the portion of the mother substrate 101 that intersects with the extension line of the dividing groove 102 is exposed. it can. The metallized paste may be applied to each ceramic green sheet before lamination of the ceramic green sheets, or may be collectively performed after lamination of the ceramic green sheets. If the hole 103 is not penetrating the mother substrate 101, the ceramic green sheets are laminated, and when the metallized paste is printed and applied after the non-penetrating, the metallized paste is easily applied to the bottom of the hole 103. Since the bottom surface is reinforced and it becomes difficult to divide well during division after firing, it is preferable to apply the metallized paste before laminating the ceramic green sheets to make them non-penetrating. In addition, when the hole 103 is formed in a plurality of layers, it may be laminated after applying the metallized paste to each ceramic green sheet, or only the ceramic green sheet in which the hole 103 is formed is first. After laminating and applying metallized paste, it may be laminated with other ceramic green sheets so as not to penetrate.

  The metallized paste for the metallized layer 104 is produced in the same manner as the metallized paste for the wiring conductor 105, but is prepared to have a viscosity suitable for application to the inner peripheral surface of the hole 103 depending on the amount of the organic binder or organic solvent.

  Here, the portion intersecting with the extended line of the dividing groove 102 indicates a portion where a line extending in the outer edge direction of the mother board 1 along the dividing groove 102 intersects with the hole 103. The width of the exposed portion is about the same as the width of the opening portion of the dividing groove 102 and should be as small as possible. If the width of the portion where the mother substrate 101 is exposed is too large, a portion where the mother substrate 101 is exposed is formed in a portion other than the extension line of the dividing groove 102, and this portion becomes the starting point of the division, In particular, since the metallized layer 104 on the inner peripheral surface of the hole 103 tends to be a starting point, it may not be divided well along the extension line of the dividing groove 102. Further, if the width of the portion where the mother substrate 101 is exposed is reduced, a portion where stress is likely to concentrate when dividing is formed on the extension line of the division groove 102, and therefore, along the extension line of the division groove 102. Can be divided well. Further, if the width of the portion where the mother substrate 101 is exposed is too small, it becomes difficult to form the portion where the mother substrate 101 is exposed by application of the metallized paste. It is preferable to be formed in a width of about 1.0 mm.

  Further, as shown in FIG. 3 which is an example of a cross-sectional view taken along line B-B ′ in FIG. 1B, the mother substrate 101 may not be exposed in the entire region in the depth direction of the hole 103. That is, even if the metallized layer 104 is formed so as to expose only the mother substrate 101 on the surface (the upper surface in FIG. 3) side where the dividing grooves 102 are formed, the hole 103 when dividing the mother substrate 101 is formed. The starting point of the division from the outer edge of the mother substrate 101 may be on the extended line of the dividing groove 102. Preferably, the metallized layer 104 is formed so as to be exposed in the entire depth direction of the hole 103 so as to be vertically divided in the thickness direction of the mother substrate 101.

  Further, the metallized layer 104 may contain glass. By including glass in the metallized layer 104, the surface of the metallized layer 104 becomes smooth and the surface of the metallized layer 104 becomes less likely to be a starting point of division, and the strength of the metallization is also improved and the effect of reinforcement is further increased. The portion where the mother board 101 is exposed is likely to be a starting point and is easily divided. Such a metallized layer 104 can be formed by using a metallized paste for the metallized layer 104 to which glass powder such as silica glass or borosilicate glass is added.

  Further, as shown in FIG. 4, the metallized layer 104 extends around the extension line of the dividing groove 102 from the hole 103 to the outer side of the mother substrate 101 on the surface of the outer peripheral portion of the region divided by the dividing groove 102. It is preferable to be formed. Since the extended metallized layer 104 ′ reinforces the periphery on the extension line of the dividing groove 102, cracks generated from the portion of the inner peripheral surface of the hole 103 where the mother substrate 101 is exposed are the metallized layer. It becomes easy to proceed along the extension line of the dividing groove 102 that is not reinforced by 104 ′, and the mother board 101 can be better divided into strip-like mother boards along the extension line of the dividing groove 102. Generation of burrs and chips on the substrate can be further suppressed.

  Furthermore, the metallized layer 104 ′ may be formed not only from the hole 103 to the outer side of the mother substrate 101 but also to extend to the surface of the mother substrate 101 around the hole 103.

  Such a metallized layer 104 ′ may be formed by applying the metallized paste for the metallized layer 104 to the inner peripheral surface of the hole 103 at the same time, or before being applied to the inner peripheral surface of the hole 103 or After application, the metallized paste for the wiring conductor 105 may be applied at the same time as it is applied.

  Further, as shown in FIG. 5, it is preferable that a second divided groove 106 shallower than the divided groove 102 is formed along the extension line of the divided groove 102 from the hole 103 to the outer side of the mother substrate 101. With this configuration, the second divided groove portion 106 has a mechanical strength relatively weaker than that of the periphery thereof. Therefore, the portion where the mother substrate 101 is exposed without the metallized layer 104 being deposited is used as a starting point. The generated crack can be easily advanced along the second dividing groove 106, and the second dividing groove 106 has higher mechanical strength than the dividing groove 104. When a force is applied from the outside when a component is mounted, the mother board 101 is prevented from inadvertently cracking from the bottom of the second dividing groove 106, so that the mother board 101 is extended from the dividing groove. It is possible to better divide the substrate into strip-shaped mother boards along the lines, and to further suppress the occurrence of burrs and chips on the wiring board.

  Similar to the divided groove 102, such a second divided groove 106 is used for the second divided groove 106 by pressing a cutter blade or a die having a V-shaped cutting edge against a ceramic green sheet for the base substrate 101. Is formed on the upper surface of the mother board 101 from the hole 103 to the outer side of the mother board 101.

  The second divided groove 106 may be formed by making a cut for the second divided groove 106 simultaneously with the cut for the divided groove 102 in the ceramic green sheet for the mother substrate 101, or the divided groove 102. It may be formed by making a notch for the second dividing groove 106 separately from the notch. In order to make the positional deviation between the dividing groove 102 and the second dividing groove 106 small, the notch for the dividing groove 102 and the notch for the second dividing groove 106 are simultaneously formed on the ceramic green sheet for the mother substrate 101. It is preferable to add. For example, by dividing the ceramic green sheet for the mother substrate 101 by using a cutter blade or a mold having different heights in the cut portion for the split groove 102 and the cut portion for the second split groove 106 A cut for the groove 102 and a cut for the second dividing groove 106 can be made simultaneously.

  The second dividing groove 106 may be formed so as to become gradually shallower from the hole 103 to the outer side of the mother substrate 101. This makes it easier to maintain the mechanical strength in the vicinity of the outer edge of the second division groove 106 portion of the mother board 101, so that the mother board 101 is inadvertently used when transporting or mounting electronic components on the mother board 101. It becomes easy to suppress cracking.

  Further, the width of the opening portion of the second dividing groove 106 is set so that the mechanical strength in the vicinity of the outer side of the second dividing groove 106 portion of the mother substrate 101 can be easily maintained. Is preferably narrower than the width of the opening of the dividing groove 102.

  In addition, on the surface of the wiring conductor 105 exposed on the surface of the multi-piece wiring board, corrosion prevention of the wiring conductor 105, connection between the electronic component and the wiring conductor 105, separated electronic component storage package and external circuit are provided. In order to strengthen the bonding with the substrate, it is preferable to perform plating such as Ni or Au.

  The electronic component storage package according to the present invention is obtained by dividing the above-described multi-cavity wiring board along the dividing grooves 102 into individual pieces. With this configuration, it is possible to obtain a good electronic component storage package in which no burr or chipping occurs on the outer edge.

  An electronic device according to the present invention includes the electronic component storage package described above and an electronic component mounted on the electronic component storage package. With this configuration, an electronic device in which electronic components are well accommodated can be obtained.

  Electronic components include semiconductor elements such as IC chips and LSI chips, piezoelectric elements such as crystal vibrators and piezoelectric vibrators, various sensors, etc., and an electronic component storage package in which a multi-piece wiring board is divided along a dividing groove. It may be mounted on a plurality of electronic components mounted on a multi-piece wiring board.

  When the electronic component is a flip-chip type semiconductor element, the electrode of the semiconductor element and the wiring conductor are connected via a solder bump, a gold bump, or a conductive resin (anisotropic conductive resin, etc.). 105, and when the electronic component is a wire bonding type semiconductor element, it is fixed with a bonding material such as glass, resin, brazing material, etc. This is performed by electrically connecting the electrode of the semiconductor element and the wiring conductor 109. When the electronic component is a piezoelectric element such as a crystal resonator, the piezoelectric element is fixed and the electrode of the piezoelectric element and the wiring conductor 105 are electrically connected by a conductive resin.

  And an electronic component is sealed as needed. Sealing is performed by covering the electronic component with a sealing resin such as epoxy resin, or a lid made of resin, metal, ceramics, etc. placed so as to cover the electronic component is bonded to glass, resin, brazing material, etc. What is necessary is just to carry out by attaching to an electronic component storage package with an agent.

  The present invention can be variously modified within a range not departing from the gist of the present invention. For example, in FIG. 1, the dividing groove 102 is formed on the upper surface of the mother substrate 101, but the dividing groove 102 may be formed on the lower surface of the mother substrate 101, or both the upper and lower surfaces of the mother substrate 101. You may form in. When the dividing grooves 102 are formed on both the upper surface and the lower surface of the mother substrate 101, the same holes 103 are formed in both ends of the dividing grooves 102 formed on the upper surface and the lower surface by the same method as described above. It ’s fine. In this case as well, the metallized layer 104 may be deposited by extending from the inner peripheral surface of the hole 103 and the outer periphery of the mother substrate 101 to the periphery of the extension line of the dividing groove 102.

  Although the mother board 101 has been described as an example of a flat plate shape, a recess for accommodating electronic components is formed on at least one of the upper surface and the lower surface of each region divided by the dividing grooves 102. It doesn't matter.

(A) is a top view which shows an example of embodiment of the multi-piece wiring board of this invention, (b) is a principal part enlarged plan view in the A section of (a). (A) is sectional drawing in the BB 'line of the multi-cavity wiring board in FIG.1 (b), (b) is CC' line of the multi-cavity wiring board in FIG.1 (b). FIG. It is a principal part expanded sectional view which shows an example of embodiment of the multi-piece wiring board of this invention. (A) is a top view which shows an example of embodiment of the multi-piece wiring board of this invention, (b) is a principal part enlarged plan view in the D section of (a). (A) is a principal part enlarged view which shows an example of embodiment of the multi-piece wiring board of this invention, (b) is sectional drawing in the E-E 'line of (a).

Explanation of symbols

101 ... Mother substrate 102 ... Divided groove 103 ... Hole 104 ... Metallized layer 105 ... Wiring conductor 106 ... Second divided groove

Claims (3)

A flat groove is formed with a dividing groove for dividing the mother substrate into a plurality of regions, and a hole having a width wider than the dividing groove and deeper than the dividing groove is formed at an end of the dividing groove. And a metallized layer is deposited on the inner peripheral surface of the hole so that the portion of the mother substrate that intersects with the extension line of the dividing groove is exposed. substrate. 2. The multi-piece wiring according to claim 1, wherein the metallized layer is continuously formed between the hole and the outer side of the mother substrate in a peripheral region of the extension line of the dividing groove. substrate. 3. The second division groove shallower than the division groove is formed on an extension line of the division groove between the hole and the outer side of the mother substrate. Multiple printed wiring board as described .

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