JP2011119660A - Multi-cavity wiring board - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a multi-cavity wiring board that reliably facilitates the identification of a failed wiring board region and has high connection reliability to, for example, an external electric circuit. <P>SOLUTION: A multi-cavity wiring board 9 includes multiple wiring board regions 2 arranged in a matrix on a motherboard 1, the wiring substrate region 2 having an electronic component mounting part 2b on the top surface and a connection pad 4 on the underside, the connection pad 4 having a surface covered with a plating layer 5 where, in the case that one of the wiring board regions 2 is identified as a defective wiring board, the wiring board region is partially or entirely removed on a part of the connection pad 4 by a laser beam in the thickness direction of the plating layer 5 and a part of the plating layer 5 or the connection pad 4 are exposed and oxidized. For example, the exposed and oxidized plating layer 5 serves as a failure detection mark, so that the mark can be easily identified. Since vaporized components or the like are not contained, the connection reliability of, for example, the connection pads 4 is not reduced by the vaporized components. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  In the present invention, a plurality of wiring board regions serving as wiring boards for mounting electronic components such as semiconductor elements and surface acoustic wave elements are arranged vertically and horizontally on a mother board. The present invention relates to a multi-piece wiring board divided into substrates.

  Conventionally, as a wiring board used for mounting electronic components such as semiconductor elements and surface acoustic wave elements, electrons are formed on the upper surface of an insulating substrate made of a ceramic sintered body such as an aluminum oxide sintered body or a glass ceramic sintered body. 2. Description of the Related Art A part having a mounting part for mounting a component and in which a plurality of metal layers made of a metal material such as tungsten is formed from the upper surface to the lower surface of an insulating substrate including the mounting part or its periphery is often used. The metal layer is a wiring conductor formed from the upper surface to the lower surface of the insulating substrate, a connection pad for external connection formed on the lower surface of the insulating substrate, or the like.

  Such a wiring board is generally manufactured in the form of a so-called multi-cavity wiring board in which a plurality of wiring boards are obtained simultaneously from a single large-area mother board. The multi-cavity wiring board has, for example, a structure in which a plurality of wiring board regions serving as wiring boards are arranged in rows and columns on a flat mother board.

  Such a multi-piece wiring board is divided into individual wiring boards by, for example, performing a cutting process such as dicing on the mother board at the boundary of the wiring board region. In general, dicing is performed in a state in which a multi-piece wiring board is attached to an adhesive tape (so-called dicing tape), and a plurality of wiring board regions (individual wiring boards) of the multi-piece wiring board cut into pieces. ) Will not fall apart.

  Before this cutting, each wiring board area is inspected for electrical characteristics, appearance, etc., and the wiring board area in which a defect is found in these inspection items is determined to be defective as an individual wiring board. Then, after being divided into individual pieces, they are peeled off from the dicing tape separately from other wiring boards (those that are not defective), and treatment such as disposal is performed. Conventionally, oil-based ink has been used for the mark for identifying the wiring board area determined to be defective. The connection pads in the wiring board region and the exposed portions of the wiring conductors are painted with oil-based ink, or circles and other figures are drawn on the surface (upper surface, etc.) of the mother board to form identification marks (so-called bad marks).

JP-A-2005-243468 JP 2002-246400 A

  However, since the multi-piece wiring board of the above-mentioned prior art has a mark for identifying a defective wiring board area as an individual wiring board drawn with oil-based ink, a large number of other inspections, cleaning, transportation, etc. There is a problem in that the mark may become thin or partially disappear when handling the individual wiring board, which may make it difficult to identify.

In addition, components evaporated from organic substances such as solvents contained in oil-based ink adhere to the surface of the wiring board area, and the connection reliability of the wiring conductor with the electronic components and the connection reliability of the connection pads to the external electric circuit are improved. There was a problem that it could be lowered.

  The present invention has been completed in view of such conventional problems, and its purpose is to easily and reliably identify a defective wiring board region, and to connect to an electronic component, an external electric circuit, or the like. An object of the present invention is to provide a multi-piece wiring board capable of producing a highly reliable wiring board.

  In the multi-cavity wiring board of the present invention, a plurality of wiring board regions are arranged vertically and horizontally on a mother board made of a ceramic sintered body, an electronic component mounting portion is provided on the upper surface of the wiring board area, and the wiring A multi-piece wiring board in which a metal layer having a plating layer deposited on the surface is formed on at least one of an upper surface and a lower surface of the substrate area, and is defective as an individual wiring board in the wiring board area In a part of the metal layer, part or all of the plating layer in the thickness direction is removed by laser light, and the part of the plating layer or the metal layer is exposed and oxidized. It is what.

  In the multi-piece wiring board of the present invention, the metal layer includes a connection pad for external connection formed on the lower surface of the wiring board region in the above-described configuration, and a piece of wiring in the wiring board region is provided. What is defective as a substrate is that a part or all of the plating layer in the thickness direction is removed by laser light in the connection pad, and a part of the plating layer or the connection pad is exposed and oxidized. It is characterized by.

  In the multi-piece wiring board of the present invention, in the above configuration, the mother board is cut by dicing along a boundary of the wiring board region, and a plurality of the connection pads are It is arranged so as to be close to the boundary of the wiring board region.

  Further, in the multi-piece wiring board of the present invention, in the above configuration, the metal layer is formed on the upper surface of the wiring board area, and the wiring board area is defective as a piece of wiring board. In at least a part of the metal layer formed on the upper surface of the wiring board region, a part or all of the plating layer in the thickness direction is removed by laser light, and a part of the plating layer or the metal layer is exposed. It is characterized by being oxidized.

  According to the multi-cavity wiring board of the present invention, a part of the wiring board region which is defective as a single wiring board is partially or entirely in the thickness direction of the plating layer by laser light in a part of the metal layer. Since this is removed and a part of the plating layer or the connection pad is exposed and oxidized, in this metal layer, the part other than the part where the plating layer is removed by the laser beam (the remaining part), Since there is a large difference in color tone, light reflectance, and the like between the plated layer or the metal layer oxidized and turned black, it is easy to identify whether or not such processing with laser light has been performed. Therefore, it is easy to identify whether each wiring board region is provided with such a mark, that is, whether it is defective as an individual wiring board.

  In addition, this mark is formed by oxidizing part of the plating layer below the part (surface part) in the thickness direction (surface part) of the plating layer removed by the laser beam or the metal layer itself. It is effectively suppressed that the oil-based ink is peeled off and thinned by handling such as inspection or conveyance. Further, a vaporizing component such as a solvent in the oil-based ink is not generated.

Accordingly, it is possible to provide a multi-piece wiring board capable of easily and surely identifying a defective wiring board region and capable of producing a wiring board having high connection reliability to an electronic component, an external electric circuit, or the like. it can.

  Further, in the multi-piece wiring board of the present invention, the processing by the laser beam is only performed on the metal layer portion and is not performed on the lower surface of the mother board. Therefore, the surface roughness on the lower surface of the mother substrate is not roughened by processing with laser light, and the adhesive force of the dicing tape to the mother substrate is not unnecessarily high. Therefore, it is easy to peel the wiring board divided into individual pieces from the dicing tape, and the productivity of the individual wiring boards can be ensured high.

  In the multi-piece wiring board of the present invention, in the above configuration, the metal layer includes a connection pad for external connection formed on the lower surface of the wiring board area, and the wiring board area is defective as an individual wiring board. In the case where a part or all of the plating layer in the thickness direction is removed by the laser beam in the connection pad, and a part of the plating layer or the connection pad is exposed and oxidized, generally, the wiring board Since a plurality of connection pads 4 formed on the lower surface of the region 2 can be used as bad marks, it is easy to recognize a wiring substrate region 2 that is defective as a wiring substrate.

  In the multi-cavity wiring board of the present invention, in the configuration in which the metal layer includes a connection pad, the mother board is cut by being subjected to dicing along the boundary of the wiring board region, When the connection pads are arranged so as to be close to the boundary of the wiring board region, a plating layer is deposited on the remaining portion of the connection pads that has not been processed by the laser beam, and this is applied to the image recognition device. Therefore, it is easy to recognize separately from the surface of the surrounding mother board, etc., so that it is easy to detect the outer peripheral position of the individual wiring board region, and positioning at the time of dicing is easy. Therefore, in this case, it is possible to provide a multi-piece wiring board with higher productivity of individual wiring boards.

  In the multi-piece wiring board of the present invention, in the above configuration, the metal layer is formed on the upper surface of the wiring board area, and the wiring board area is defective as a piece of wiring board. When at least part of the metal layer formed on the upper surface of the metal layer is partly or wholly removed in the thickness direction of the plating layer by the laser beam, and part of the plating layer or the metal layer is exposed and oxidized Since a bad mark is formed on the upper surface, which is the surface exposed to the front when dividing the multi-piece wiring board into pieces, it is easier to recognize a defective wiring board region as a piece of wiring board. be able to.

(A) is a top view which shows an example of embodiment of the multi-piece wiring board of this invention, (b) is the bottom view. It is a principal part expanded bottom view which expands and shows the principal part of the multi-cavity wiring board shown in FIG. (A) And (b) is a principal part expanded sectional view which shows an example of the cross section in the principal part of the multi-piece wiring board of this invention, respectively. (A) And (b) is a principal part expanded bottom view which shows the other example of embodiment of the multi-piece wiring board of this invention, respectively. (A) And (b) is a principal part expanded bottom view which shows the other example of embodiment of the multi-piece wiring board of this invention, respectively. (A) And (b) is a principal part enlarged top view which shows the other example of embodiment of the multi-piece wiring board of this invention, respectively. (A) And (b) is a principal part enlarged top view which shows the other example of embodiment of the multi-piece wiring board of this invention, respectively.

  A multi-piece wiring board of the present invention will be described with reference to the accompanying drawings.

  In the description of the following embodiments, a case where a metal layer used as a bad mark is a connection pad formed on the lower surface of the wiring board region will be mainly described as an example.

  FIG. 1A is a top view showing an example of an embodiment of a multi-piece wiring board according to the present invention, FIG. 1B is a bottom view thereof, and FIG. 2 is a plan view of FIG. It is a principal part expansion bottom view which expands and shows a principal part. A plurality of wiring board regions 9 are basically formed by arranging a plurality of wiring board regions 2 vertically and horizontally on the mother board 1.

  The mother substrate 1 is a ceramic sintered body such as a glass ceramic sintered body, an aluminum oxide sintered body, an aluminum nitride sintered body, a silicon carbide sintered body, a silicon nitride sintered body, and a mullite sintered body. It is formed with the insulating material which consists of. In the example of this embodiment, a dummy area 8 is provided on the outer periphery of the mother board 1 so as to surround the plurality of wiring board areas 2 arranged. The dummy area 8 is provided to facilitate handling of the multi-piece wiring board 9.

  The plurality of wiring board regions 2 arranged on the mother board 1 are areas that each become an individual wiring board (not shown). By cutting the mother board 1 at the boundary 2a of the wiring board region 2, a plurality of wiring boards are manufactured simultaneously and collectively.

  The individual wiring substrate is used as an electronic component mounting substrate, for example, and an electronic component mounting portion 2b is provided at the center or lower surface of the upper surface of the wiring substrate region 2. In the example shown in FIG. 1, a concave portion (not shown) is provided in the central portion of the upper surface of the wiring board region 2, and the bottom surface of the concave portion is a mounting portion 2b for electronic components.

  Note that the mother board 1 does not have to have such a recess in the wiring board region 2, and is part of a flat upper surface of the wiring board region 2 as a flat plate (not shown). May be the mounting portion 2b.

  Electronic components (not shown) mounted on the mounting portion 2b include semiconductor integrated circuit elements such as IC and LSI, and optical semiconductors such as LED (light emitting diode), PD (photodiode), and CCD (charge coupled device). Various semiconductor devices including elements, piezoelectric elements such as surface acoustic wave elements and crystal resonators, capacitive elements, resistors, and micromachines (so-called MEMS elements) in which minute electromechanical mechanisms are formed on the surface of a semiconductor substrate Electronic parts are mentioned.

  The electronic component has a resin adhesive such as an epoxy resin, polyimide resin, acrylic resin, silicone resin, polyether amide resin, Au-Sn, Sn-Ag-Cu, Sn- Bonded with solder such as Cu, Sn-Pb, or glass.

  On at least one of the upper surface and the lower surface of the mother board 1, metal layers (not shown) such as wiring conductors 3 and connection pads 4 are formed. For example, the metal layer joins a conductive path for electrically connecting an electronic component mounted on the mounting portion 2b and an external electric circuit, or a lid (not shown) for sealing the electronic component. Forming a base metal layer or the like.

In the example shown in FIG. 1, the wiring conductor 3 is formed on the mother board 1 from the outer peripheral portion of the mounting portion 2 b to the lower surface of the wiring board region 2. The wiring conductor 3 is electrically connected to an electronic component mounted on the mounting portion 2b and functions as a part of a conductive path that electrically connects the electronic component to an external electric circuit. Such wiring conductors 3 are tungsten, molybdenum, manganese, copper silver,
It is made of a metal material such as palladium, platinum, or gold.

  If the wiring conductor 3 is made of, for example, tungsten, a metal paste is prepared by kneading tungsten powder together with an organic solvent and a binder, and the metal paste is printed in a predetermined pattern on a ceramic green sheet serving as the mother substrate 1. Then, it can be formed by a method of simultaneous firing.

  The electrical connection between the electronic component and the wiring conductor 3 is performed by, for example, connecting an electrode (not shown) of the electronic component to a portion of the wiring conductor 3 exposed at the outer peripheral portion of the mounting portion 2b, bonding wire, solder, or the like. It can be performed by connecting via a conductive connecting material (not shown).

  Connection pads 4 are formed on the lower surface of the wiring board region 2. The connection pads 4 are used to electrically connect individual wiring boards (actually, electronic devices in which electronic components are mounted on the wiring boards) (not shown) to an external electric circuit. For example, when the connection pad 4 is connected to a predetermined position of the external electric circuit via a conductive connecting material such as solder or conductive adhesive, the wiring board is electrically connected to the external electric circuit. Further, if the connection pad 4 is electrically connected to the wiring conductor 3, the electronic component and the external electric circuit can be electrically connected via the wiring conductor 3 and the connection pad 4.

  A plated layer 5 of, for example, nickel or gold is applied to the exposed portions of these connection pads 4 and wiring conductors 3 in order to make the connection with bonding wires, solder, etc. easy and strong.

  The multi-piece wiring board 9 is bonded to an adhesive tape (so-called dicing tape) whose adhesive strength can be weakened by irradiating ultraviolet rays, for example, and is subjected to dicing processing. Divided into wiring boards. Each wiring board divided into individual pieces is attached to the dicing tape, so that it does not fall apart, and for example, handling such as transport and setting for mounting electronic parts is easy. Electronic components are mounted on the wiring board divided into individual pieces after a defective wiring board as described later is removed from the dicing tape.

  In the multi-cavity wiring board 9 of the present invention, the defective part of the wiring board region 2 is the thickness of the plating layer 5 by laser light in a part of the connection pad 4 which is a metal layer. Part or all of the direction is removed, and a part of the plating layer 5 or the connection pad 4 is exposed and oxidized. In FIG. 1, a part of the plating layer 5 or an exposed part of the connection pad 4 is omitted.

  What is defective as an individual wiring board is, for example, a defect such as a disconnection or an electrical short between the wiring conductor 3 or the wiring conductor 3 and the connection pad 4, a capacitance, an electric resistance, or an impedance in the wiring conductor 3. Such as deviations from the standard values of the electrical characteristics, discoloration of the wiring conductors 3 and connection pads 4, etc., chipping of the entire wiring board region 2 and adhesion of foreign matters. These defects and the like are detected by measurement of electrical characteristics and appearance inspection by an image recognition apparatus.

  Then, with respect to the wiring board region 2 which is defective as such an individual wiring board, the plating layer 5 is formed in a part of the connection pad 4 (for example, the central part as shown in FIG. 2) as described above. Since part of the thickness direction or the connection pad 4 is exposed and oxidized, the oxidized part becomes an identification mark, and it is easy to determine that the wiring board region 2 (wiring board) is defective. Can be identified.

  That is, as described above, a part of the plating layer 5 in the thickness direction or the connection pad 4 is exposed and oxidized, so that a part of the connection pad 4 from which the plating layer 5 has been removed by the laser beam is removed. Color tone and light reflectance between the other part (remaining part) and the part of the plating layer 5 or the connection pad 4 oxidized and turned black (between the central part and the outer peripheral part in the example shown in FIG. 2) Therefore, it is easy to identify whether or not processing with such a laser beam has been performed. Therefore, it is easy to identify whether each wiring board region 2 is provided with such a mark, that is, whether it is defective as an individual wiring board.

  This mark is formed by oxidizing a part of the plating layer 5 on the lower side (surface part) in the thickness direction of the plating layer 5 removed by the laser beam or the connection pad 4 itself. Therefore, it is effectively suppressed that the applied oil-based ink is peeled off and thinned by handling such as inspection or conveyance. Further, a vaporizing component such as a solvent in the oil-based ink is not generated.

  Therefore, there is provided a multi-piece wiring board 9 which can easily and reliably identify a defective wiring board region 2 and which can produce a wiring board with high connection reliability to an electronic component, an external electric circuit or the like. be able to.

  Further, the processing with the laser beam is performed only on the connection pad 4 and is not performed on the surface of the mother substrate 1. Therefore, the surface roughness on the lower surface of the mother substrate 1 is not roughened by processing with laser light, and the adhesive force of the dicing tape to the mother substrate 1 is not unnecessarily high. Therefore, it is easy to peel the wiring board divided into individual pieces from the dicing tape, and the productivity of the individual wiring boards can be ensured high.

  In the multi-piece wiring board of the present invention, as described above, the metal layer includes the connection pads 4 for external connection formed on the lower surface of the wiring board region 2, and the individual wiring board in the wiring board region 2. As for what is defective, a part or all of the plating layer 5 in the thickness direction is removed by a laser beam in a part of the connection pad 4, and a part of the plating layer 5 or the connection pad 4 is exposed and oxidized. In general, since a plurality of connection pads 4 formed on the lower surface of the wiring board region 2 can be used as bad marks, the wiring board region 2 that is defective as a wiring board can be easily recognized.

  For example, even when it is difficult to form an easily identifiable bad mark on the upper surface side, such as when the area of the metal layer such as the wiring conductor 3 formed on the upper surface side of the wiring board region 2 is small or the number is small. By removing the plating layer 5 from the connection pad 4 with a laser beam, a bad mark that can be easily identified can be formed in the wiring board region 2.

  Note that the connection pad 4 as a metal layer for forming a bad mark is difficult to identify because the entire surface is oxidized and changed to black or the like when the plating layer 5 is removed by laser light on the entire surface. . For this reason, the above processing by the laser beam is performed on a part of the center portion of the connection pad 4 and the like. In this case, in order to prevent laser light from being accidentally irradiated onto the lower surface of the mother substrate 1 due to misalignment of the processing, etc., it is preferable to perform processing using the laser light while avoiding the outer periphery of the connection pad 4. .

  In addition, before removing the plating layer 5 with the laser beam as described above, the connection pad 4 is marked on the surface with oil-based ink within the range to be removed, and the plating layer 5 including this oil-based ink is included. May be removed with a laser beam. In this case, since the oil-based ink does not remain on the multi-piece wiring board after processing, there is no problem as in the prior art. Further, since the marking is made with oil-based ink, it is easy to recognize the wiring board region 2 and the connection pad 4 to be laser processed, which is advantageous in terms of the productivity of the multi-piece wiring board.

  The processing range (pattern) by such a laser beam is not limited to a quadrangular shape similar to the connection pad 4 as shown in FIG. 2, but a circular shape, an elliptical shape, a square frame shape, an annular shape, an elliptical shape, or the like. Other patterns such as a ring may be used.

  As a laser beam used for this processing, for example, a YAG (yttrium-aluminum-garnet) laser having a wavelength of about 0.8 to 1.3 μm can be used.

  Further, as shown in FIG. 3A, for example, as shown in FIG. 3A, a nickel plating layer 5a and a gold plating layer 5b are deposited in order from the surface of the connection pad 4 on a part of the plating layer 5 removed by the laser beam. It is the gold plating layer 5b when it is. Further, in the case where the plating layer 5 is entirely removed in the thickness direction and the connection pad 4 is exposed, for example, as shown in FIG. 3A and 3B are main part enlarged cross-sectional views showing an example of the cross section of the main part of the multi-cavity wiring board 9 of the present invention. In FIG. 3, the same parts as those in FIGS. 1 and 2 are denoted by the same reference numerals.

  The plating layer 5 is not limited to the nickel plating layer 5a and the gold plating layer 5b as described above, but a plating layer (not shown) made of another metal material such as a nickel-cobalt alloy, copper, palladium, platinum, or tin. It may be. If the plating layer 5 is only one layer, the connection pad 4 is exposed and oxidized when the plating layer 5 is completely removed in the thickness direction.

  If the plating layer 5 is, for example, a nickel plating layer 5a, plating is performed at a predetermined current density and time in a state where a large number of wiring boards 9 are immersed in a nickel plating solution for electrolytic plating mainly composed of nickel sulfate. If a current for supplying is supplied to each connection pad 4, it can be deposited. In this case, a current for plating can be supplied to the connection pad 4 through the wiring conductor 3. At this time, a nickel plating layer (not shown) is also applied to the exposed portion of the wiring conductor 3 in the same manner as the connection pad 4. Can be applied. In the case of the plating layer made of the gold plating layer 5b and other metal materials, the nickel plating layer can be obtained by appropriately changing the plating solution to be used according to each metal material (for example, changing to a cyan-based gold plating solution). It can be applied in the same manner as 5a.

  Here, a specific example of processing using laser light will be described.

The wiring board region 2 has a rectangular shape with a side length of 2 × 2.2 mm, and in the multi-piece wiring board 9 arranged in a row of 12 × 12 on the mother board 1, the connection pads 4 are When one side of the tungsten metallization layer is formed into a square shape having a length of about 0.4 mm and arranged at the four corners of the lower surface of the wiring board region 2 and one at the center of each side, On the surface, a nickel plating layer 5a having a thickness of about 2 to 10 μm and a gold plating layer 5b having a thickness of about 0.5 to 1 μm
Were sequentially deposited.

  Then, 100 multi-piece wiring boards 9 (14400 wiring board areas 2) are inspected for electrical characteristics and appearance, and the wiring board area 2 (64 which is determined to be defective as an individual wiring board by this inspection). Are processed using a YAG laser with an output of 10 W (watts) in a square area with a side length of about 0.35 mm at the center of the connection pad 4 to remove the gold plating layer 5b. The nickel plating layer 5a was exposed and oxidized. The exposed portion of the oxidized nickel plating layer 5a was nickel oxide, and the color tone was black.

A dicing tape (not shown) having a thickness of about 500 μm is attached to the entire lower surface of these multi-cavity wiring boards 9 to identify the defective wiring board (wiring board region 2). Performed. As a result, all the nickel plating layer 5a exposed and oxidized as described above was detected by the image recognition apparatus. Although visual detection was also performed, in this case, detection was easy.

  In addition, after dividing the wiring board into pieces, after connecting the connection pads 4 to the external electric circuit (copper plating circuit of the printed wiring board) using solder, the wiring board is connected to the external electric circuit. A peeling test (peeling test) was performed. As a result, it was confirmed that the peeling mode was destruction inside the solder, and the strength of the connection between the solder and the connection pad 4 was sufficiently strong.

On the other hand, the mark drawn on the defective wiring board region 2 using oil-based ink according to the prior art has a ratio of about 0.9% under the same conditions as the specific example of the multi-cavity wiring board 9 of the present invention. Some marks were not identified. Further, in the above-described peeling test, about 0.1% of the wiring board was broken at the interface between the solder and the connection pad 4, and the solder was peeled off.

  Note that the connection pads 4 are not limited to a plurality of connection pads 4 arranged along the outer periphery of the wiring board region 2 as in the example shown in FIG. 1. For example, as shown in FIG. In the case of only one, or as shown in FIG. 4B, a plurality may be arranged in the center of the wiring board region 2. 4 (a) and 4 (b) are enlarged bottom views of main parts showing another example of the embodiment of the multi-piece wiring board 9 of the present invention. 4, parts similar to those in FIGS. 1 and 2 are denoted by the same reference numerals.

  The example shown in FIG. 4A is a case where the grounding connection pad 4 is provided on the lower surface of the wiring board region 2 as wide as possible to stabilize the grounding. In this example, the center portion of the connection pad 4 is processed with a laser beam within a square frame shape, and a part of the plating layer 5 in the thickness direction or the connection pad 4 is exposed and oxidized. The example shown in FIG. 4B is a case where a large number of connection pads 4 are arranged in accordance with the electrode pads when, for example, a semiconductor element having a large number of electrodes is mounted as an electronic component. is there. In this example, only the one located on the outer periphery of the plurality of connection pads 4 arranged vertically and horizontally is processed with a laser beam to expose a part in the thickness direction of the plating layer 5 or the connection pads 4. Let it oxidize. Keeping the range of processing by laser light small is advantageous in maintaining high productivity.

  As described above, the multi-piece wiring board 9 is subjected to dicing processing at the boundary 2a of the wiring board area 2 (in this example, the boundary between the wiring board areas 2 and the boundary between the wiring board area 2 and the dummy area 8). Then, each individual wiring board region 2 is cut to be divided into individual wiring boards.

The cutting of the mother board 1 by dicing is performed by rotating a dicing blade in which abrasive grains such as diamond are bonded with a binder such as glass or resin material at a high speed (about 5000 to 15000 rpm). 2 is performed by cutting the mother substrate 1 at the boundary 2a. The positioning of the dicing blade with respect to the mother board 1 is performed, for example, by providing a positioning pattern (not shown) on the mother board 1 in advance and recognizing the position with an image recognition device. This positioning pattern can be formed on the mother board 1 by the same method using the same material as the wiring conductor 3, for example. Further, the positioning pattern may be formed by adding a colorant such as a pigment to the same material as that for forming the mother substrate 1. Further, not only such a pattern but also a notch (not shown) formed by notching a part of the outer edge of the mother board 1 or the like may be used as a positioning reference.

Further, the multi-cavity wiring board 9 has a mother board 1 that is connected to the wiring board region 2 as described above, for example.
In the case where a plurality of connection pads 4 are arranged so as to be close to the boundary 2a of the wiring board region 2, the connection pads 4 are cut. Among them, the plating layer 5 is deposited on the remaining portion that has not been processed by the laser beam, and it is easy to recognize this by an image recognition device or the like, so that the outer peripheral position of the individual wiring board region 2 can be detected. It is easy, and positioning during dicing is easy. Therefore, in this case, it is possible to provide a multi-piece wiring board 9 with higher productivity of individual wiring boards.

  In this case, if the connection pad 4 is processed by laser light while avoiding the outer periphery of the connection pad 4 as described above, the light reflectance on the outer periphery of the connection pad 4 is relatively high and identification is easy. Since the plating layer 5 remains, it is easy to detect the position of the outer periphery of the connection pad 4 and the position of the boundary 2a of the wiring board region 2 adjacent thereto.

  In order to obtain such an effect at the time of dicing, the connection pads 4 are not necessarily all along the outer side of the lower surface of the wiring board region 2 as shown in FIG. It does not have to be arranged so that the distance from the outer side is the same. For example, as shown in FIG. 5 (a), in the case of being arranged at four corners on the lower surface of the rectangular wiring board region 2, or as shown in FIG. Even when the pad 4 is farther from the boundary 2a of the wiring board region 2 than the others, the outer peripheral position of the individual wiring board region 2 can be detected based on the position of the connection pad 4. . 5 (a) and 5 (b) are enlarged bottom views of the main part showing another example of the embodiment of the multi-piece wiring board 9 of the present invention. 5, parts similar to those in FIGS. 1 and 2 are denoted by the same reference numerals.

  The example shown in FIG. 5A is a case of a wiring board (wiring board region 2) in which a surface acoustic wave element having four electrodes for connection is mounted as an electronic component, for example, FIG. In the example shown in FIG. 5, for example, when a semiconductor element having a large calorific value during operation is mounted as an electronic component, the connection pads 4 are arranged so as to avoid corners on the lower surface of the wiring board region 2, and This is a case where the thermal stress when the wiring board is connected to the external electric circuit is suppressed from being concentrated on some of the connection pads 4.

(When the metal layer is formed on the upper surface of the mother board 1)
In the following embodiments, a case where the metal layer used as a bad mark is a metal layer formed on the upper surface of the wiring board region 2 will be described as an example. In this embodiment, the metal layer from which a part of the plating layer 5 is removed by the laser beam is formed on the upper surface of the wiring board region 2. Unlike the case of the connection pad 4), the other points are the same. The description of the same parts as those in the above embodiment will be omitted.

  6A and 6B are main part top views showing main parts in another example of the embodiment of the multi-cavity wiring board of the present invention. 6, parts similar to those in FIGS. 1 and 2 are denoted by the same reference numerals.

  The multi-cavity wiring board shown in FIG. 6A has the configuration of the multi-cavity wiring board of the present invention, and a plurality of wiring conductors 3 are formed on the upper surface of the wiring board region 2 as a metal layer. Yes. On the surface of the wiring conductor 3, a nickel plating layer or a gold plating layer (in FIG. 6) is used in order to make the connection of a conductive connecting material such as a bonding wire or solder easier and stronger. And a plating layer 5 such as (not shown) is applied. Of the wiring board regions 2, those that are defective as individual wiring boards are formed by the laser beam on at least a part of the wiring conductor 3 (metal layer) formed on the upper surface of the wiring board region 2. Part or all of the thickness direction is removed, and a part of the plating layer 5 or the wiring conductor 3 is exposed and oxidized.

  In the example shown in FIG. 6A, in all the wiring conductors 3, the plating layer 5 at the center of the wiring conductor 3 is completely removed in the thickness direction to expose the surface of the wiring conductor 3 as a metal layer. And oxidizing. Since many wiring conductors 3 are formed on the upper surface of the wiring board region 2, it is easy to identify a defective wiring board region 2 from the upper surface side of the multi-wiring wiring substrate 9.

  In the multi-piece wiring board shown in FIG. 6B, a metal layer is used as a bonding layer 6 for bonding an electronic component to the mounting portion 2b of the wiring board region 2 via a bonding material such as a gold-silicon brazing material. Is formed. The bonding layer 6 is coated with a plating layer 5 in the same manner as the connection pad 4 in order to make the bonding of a bonding material such as a brazing material easier and stronger. Also in this example, a part of the wiring board region 2 which is defective as a single wiring board is partly or entirely removed in the thickness direction of the plating layer 5 by laser light in at least a part of the bonding layer 6. A part of the plating layer 5 or the wiring conductor 3 is exposed and oxidized.

  In the example shown in FIG. 6B, the plating layer 5 is entirely removed in the thickness direction in a rectangular area slightly smaller than the rectangular bonding layer 6 at the central portion of the bonding layer 6 to obtain a metal layer. The surface of the bonding layer 6 is exposed and oxidized. Since the bonding layer 6 is generally formed in a larger pattern than the wiring conductors 3 and the connection pads 4, it is easy to identify when the plating layer 5 is removed and exposed and oxidized.

  In the case of the wiring conductor 3 and the bonding layer 6 as well, the range in which the plating layer 5 is removed is not limited to a quadrangular shape, but a polygonal shape other than a square such as a circular shape, an elliptical shape, an annular shape, a frame shape, or a triangular shape, or indefinite. The shape may be a shape or a symbol.

  In this way, the metal layer is formed on the upper surface of the mother substrate 1, and plating is performed by laser light on at least a part of the metal layer (wiring conductor 3, bonding layer 6, etc.) formed on the upper surface of the wiring substrate region 2. When a part or all of the thickness direction of the layer 5 is removed and a part of the plating layer 5 or the metal layer is exposed and oxidized, the surface of the multi-layer wiring board 9 is divided into pieces. Since the bad mark is formed on the upper surface which is the surface exposed to the wiring board, it is possible to more easily recognize the wiring board region 2 which is defective as an individual wiring board.

  Irradiation of laser light to the metal layers on the upper surface of the mother substrate 1 such as the wiring conductor 3 and the bonding layer 6 may be performed under the same conditions as in the case of the connection pads 4.

  When the wiring conductor 3 on the upper surface of the mother board 1 is a metal layer from which a part of the plating layer 5 is removed by laser light, the dimensions such as the line width of each wiring conductor 3 are smaller than those of the connection pads 4. May be small. In this case, it is difficult to remove the plating layer 5 by irradiating the central portion of each wiring conductor 3 with laser light. Therefore, for example, as shown in FIG. 7 (a), a laser beam is irradiated in a pattern that connects a plurality of wiring conductors 3 arranged along the length direction in the line width direction. You may make it expose the wiring conductor 3 which is a part or a metal layer. At this time, even if the surface roughness of the mother substrate 1 becomes rough due to laser light irradiation, if the upper surface is not attached to the dicing tape (the dicing tape is attached to the lower surface of the mother substrate 1). Therefore, the dicing tape is not easily peeled off from the mother board 1.

Further, the metal layer to be the bad mark formed on the upper surface of the mother substrate 1 may be a dummy metal layer 7 as shown in FIG. 7B, for example. Unlike the wiring conductor 3 and the connection pad 4, the dummy metal layer 7 is not electrically connected to the electronic component mounted on the mounting portion 2 b, and is simply attached to the upper surface of the mother board 1, for example. 7A and 7B are top views showing other examples of the embodiment of the multi-piece wiring board of the present invention. 7, parts similar to those in FIGS. 1, 2 and 6 are denoted by the same reference numerals.

  In the example shown in FIG. 7B, a circular dummy metal layer 7 is formed at the corner (upper right corner) of the wiring board region 2 outside the mounting portion 2b, and the central portion of the dummy metal layer 7 is formed. The plating layer 5 is completely removed in the thickness direction. The dummy metal layer 7 can also be used as an index mark for indicating the position of a specific wiring conductor 3 in a normal wiring board region 2 (a piece of wiring board).

  In the example shown in FIGS. 6 and 7, the metal layer (wiring conductor 3, bonding layer 6, dummy metal on the upper surface of the wiring board region 2 in the defective wiring board region 2 as the individual wiring board. When the layer 7) is a bad mark, the plating layer 5 is completely removed in the thickness direction. In these examples, only a part of the plating layer 5 in the thickness direction (for example, a gold plating layer) is removed. Then, the surface of a part of the exposed plating layer 5 (for example, a nickel plating layer) may be oxidized.

DESCRIPTION OF SYMBOLS 1 ... Mother board 2 ... Wiring board area | region 2a .... Border 2b of wiring board area | region ... Mounting part 3 ... Wiring conductor 4 ... Connection pad 5 ... Plating layer 5a ... Nickel plating layer 5b ··· Gold plating layer 6 ··· Bonding layer 7 ··· Dummy metal layer 8 ··· Dummy region 9 · · · Multiple wiring substrate

Claims (4)

A plurality of wiring board regions are arranged vertically and horizontally on a mother board made of a ceramic sintered body, an electronic component mounting portion is provided on the upper surface of the wiring board region, and at least one of the upper surface and the lower surface of the wiring board region A multi-piece wiring board having a metal layer with a plating layer deposited on the surface,
Among the wiring board regions, those which are defective as individual wiring boards are partly or entirely removed in the thickness direction of the plating layer by laser light in part of the metal layer, and part of the plating layer. Alternatively, the multi-layer wiring board is characterized in that the metal layer is exposed and oxidized. The metal layer includes a connection pad for external connection formed on the lower surface of the wiring board region, and the wiring board region that is defective as a single wiring board is formed by a laser beam in the connection pad. 2. The multi-cavity wiring board according to claim 1, wherein a part or all of the plating layer in the thickness direction is removed, and a part of the plating layer or the connection pad is exposed and oxidized. The mother board is cut by dicing along the boundary of the wiring board region, and a plurality of the connection pads are arranged so as to be close to the boundary of the wiring board region. The multi-cavity wiring board according to claim 2, wherein: The metal layer is formed on the upper surface of the wiring board region, and one of the wiring board regions that is defective as an individual wiring substrate is at least one of the metal layers formed on the upper surface of the wiring board region. 2. The large number of portions according to claim 1, wherein a part or all of the plating layer in the thickness direction is removed by a laser beam in the part, and a part of the plating layer or the metal layer is exposed and oxidized. Individual wiring board.

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