JP2011066122A - Circuit board - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To securely prevent peeling and damages such as cracking of a terminal electrode layer provided to a support substrate. <P>SOLUTION: The peripheral part 31 of the terminal electrode layer 3 provided to one principal surface of the support substrate 9 is continuously covered with a resist layer 2 except a part thereof to reinforce bonding between the terminal electrode layer 3 and support substrate 9, thereby preventing peeling of the terminal electrode layer 3 from the support substrate 9. Further, when coefficients of thermal expansion of the support substrate 9, terminal electrode layer 3 and resist layer 2 are greatly different from one another, for example, even when the support substrate 9, terminal electrode layer 3 and resist layer 2 are heated and expanded, and stress is produced, during a reflow treatment, since the produced stress is released through the part of the terminal electrode layer peripheral part 31, which is not covered with the resist layer 2, the terminal electrode layer 3 is prevented from peeling from the support substrate 9 or cracking. <P>COPYRIGHT: (C)2011,JPO&amp;INPIT

Description

  The present invention relates to a circuit board in which a pattern of a terminal electrode layer is formed on at least one main surface of a support substrate.

  Conventionally, a circuit board mounted on a mother board has a pattern of terminal electrode layers such as lands and pads formed on at least one main surface of the support board. The terminal electrode layer is made of an electrode material such as copper foil, and the support substrate has a single layer or multilayer structure using an insulating material such as resin or ceramic. Since the material for forming the terminal electrode layer and the material for forming the support substrate are different materials and may be peeled off due to mechanical friction or temperature change, the terminal electrode layer and the support substrate Various attempts have been made to reinforce the bonding. For example, the peripheral portion of the terminal electrode layer provided on at least one main surface of the support substrate is covered with an insulating material (resist) so that the terminal electrode layer is pressed against the support substrate, and the terminal electrode layer and the support substrate are bonded. It has been proposed to reinforce (see Patent Documents 1 and 2).

  As shown in FIGS. 7A and 7B, in the circuit board 300 described in Patent Document 1, the outer peripheral portion 301 a of the terminal electrode layer formed of the conductor pad 301 is covered with the overcoat material 302 over the entire periphery. ing. On the other hand, as shown in FIG. 8, in the circuit board 400 described in Patent Document 2, two portions of the terminal electrode layer made of the conductor 401 are covered with the protective glass 402 with the opening 403 sandwiched therebetween, whereby the conductor land 401a. Is formed. 7A and 7B are a sectional view and a plan view of the circuit board, respectively, and FIG. 8 is a plan view of the circuit board.

JP 2002-198637 (paragraphs [0018], [0020], [0021], FIG. 1, abstract, etc.) Japanese Patent Laid-Open No. 9-213881 (paragraphs [0010], [0012], FIG. 1, etc.)

  In the circuit board 300 shown in FIGS. 7A and 7B, the outer peripheral portion 301a of the conductor pad 301 is covered with the overcoat material 302 over the entire periphery and pressed against the substrate. The overcoat material 302 reinforces the bonding with the. However, when the support substrate 303, the overcoat material 302, and the conductor pad 301 are heated at the time of solder reflow or the like, the conductor pad 301 is moved from the outer peripheral side by the overcoat material 302 based on the difference in coefficient of thermal expansion. When pressed toward the center, the conductor pad 301 may be lifted and peeled off from the support substrate 303, and the conductor pad 301 may be cracked.

  On the other hand, in the circuit board 400 shown in FIG. 8, two portions of the conductor 401 are covered with the protective glass 402 with the opening 403 interposed therebetween and pressed against the board. In this case, since the conductor 401 is partially covered with the protective glass 402 only at the two peripheral portions, the force of the protective glass 402 pressing the conductor 401 against the support substrate is compared with the example of the circuit board 300 in FIG. The connection between the support substrate and the conductor 401 may not be sufficiently reinforced.

  Further, although the plurality of conductor lands 401a are disposed adjacent to each other, since the protective glass 402 is not provided between the adjacent conductor lands 401a, the conductor lands 401a may be short-circuited by a joining member such as molten solder. is there.

  The first object of the present invention is to reliably prevent damage such as peeling and cracking of the terminal electrode layer provided on the support substrate, and the support substrate is provided with a plurality of terminal electrode layers in an island shape. In some cases, the second object is to prevent short-circuiting between the layers with molten solder or the like.

  In order to achieve the first object described above, a circuit board according to the present invention includes a support substrate, a terminal electrode layer provided on at least one main surface of the support substrate, and partially covering the terminal electrode layer. A resist layer, and the resist layer is provided so as to continuously cover the peripheral portion of the terminal electrode layer excluding at least one edge side of the support substrate. (Claim 1).

  Further, the resist layer of the circuit board according to the present invention is such that the resist layer has a point where the overlapping portion of the terminal electrode layer and the resist layer is one point on the terminal electrode layer excluding the peripheral portion. It includes at least three points of intersections between the X-axis and Y-axis of the −Y coordinate axis and the peripheral edge of the terminal electrode layer (claim 2).

  In order to achieve the second object, the circuit board of the present invention includes a plurality of the terminal electrode layers provided in an island shape along an edge of the main surface, and the resist layer includes the main layer. It is characterized by being provided so as to cover each terminal electrode layer of the surface and the central portion of the main surface (Claim 3).

  In the circuit board according to the present invention, the resist layer is provided so as to cover all corners of the terminal electrode layer.

  According to the invention of claim 1, since the resist layer is provided so as to continuously cover the peripheral portion of the terminal electrode layer excluding the edge side of the support substrate, the terminal electrode layer is pressed against the support substrate by the resist layer. Thus, the bonding between the terminal electrode layer and the support substrate is sufficiently reinforced. In this case, even if a mechanical impact is applied, the terminal electrode layer does not easily peel from the support substrate.

  In addition, since a part of the peripheral portion of the terminal electrode layer is not covered with the resist layer, for example, when the solder reflow is performed, the support substrate, the terminal electrode layer, and the resist layer are heated, and the terminal electrode is generated due to a difference in thermal expansion coefficient between them. The force to lift the layer is released from the portion not covered by the resist layer around the terminal electrode layer, and the terminal electrode layer is not peeled off from the support substrate or cracked.

  In addition, even when the support substrate, terminal electrode layer, and resist layer are heated and expanded during solder reflow, the force (strain) that causes the terminal electrode layer to lift up is affected by the resist layer around the terminal electrode layer. Therefore, the portion that is not covered with the base plate is released to the edge of the support substrate, and the other portions of the support substrate are not affected. Therefore, damage to the terminal electrode layer due to mechanical impact or heating can be reliably prevented, and the reliability of the circuit board is improved.

  According to the invention of claim 2, the resist layer continuously covers a peripheral portion of the terminal electrode layer provided on at least one main surface of the support substrate except for a part thereof, and the terminal electrode layer and the resist The overlapping portion with the layer includes at least three points among the intersections of the X-axis and Y-axis of the XY coordinate axis and the peripheral edge of the terminal electrode layer with one point on the terminal electrode layer excluding the peripheral portion as the origin. Thus, the terminal electrode layer is efficiently pressed into the support substrate from three directions by the resist layer, and the bonding between the terminal electrode layer and the support substrate is sufficiently reinforced. In this case, even if a mechanical impact is applied, the terminal electrode layer does not easily peel from the support substrate. Therefore, damage to the terminal electrode layer can be prevented more reliably.

  According to the invention of claim 3, the plurality of terminal electrode layers are provided in an island shape along the edge of the main surface of the support substrate, and the resist layer is provided on each of the main surfaces of the support substrate on which the terminal electrode layer is provided. Since it is provided so as to cover the terminal electrode layers and the central portion, the resist layer provided between the terminal electrode layers prevents, for example, molten solder from short-circuiting the terminal electrode layers, so that the support substrate has an island shape. A short circuit between a plurality of provided terminal electrode layers can also be reliably prevented.

  According to the invention of claim 4, since the resist layer is provided so as to cover all the corners of the terminal electrode layer, the corner that is a corner portion of the terminal electrode layer that is likely to be peeled off from the support substrate. Are all pressed against the support substrate by the resist layer, so that the terminal electrode layer can be more reliably prevented from peeling from the support substrate.

It is sectional drawing which shows 1st Embodiment of a component built-in module provided with the circuit board of this invention. It is a bottom view of FIG. It is a bottom view which shows 2nd Embodiment of the component built-in module of FIG. It is a bottom view which shows the modification of the component built-in module of FIG. It is a bottom view which shows the modification of the component built-in module of FIG. (A)-(c) is a figure which shows the modification of a terminal electrode layer. It is a figure which shows an example of the conventional circuit board, Comprising: (a) is sectional drawing, (b) is a top view. It is a top view which shows an example of the conventional circuit board.

<First Embodiment>
1st Embodiment of the component built-in module 1 provided with the circuit board of this invention is described with reference to FIG. 1 and FIG.

  FIG. 1 is a cross-sectional view showing a first embodiment of a component built-in module 1 including a circuit board 10 of the present invention. As shown in FIG. 1, the component built-in module 1 includes a resist layer 2, a terminal electrode layer 3, a connection layer 4, a component built-in layer 5, wiring layers 6 and 8, and a core substrate 7 laminated together. It is formed. Further, the electronic component IC is mounted on the component built-in module 1 by connecting the wiring layer 8 and the terminal electrode tIC of the electronic component IC.

  The component built-in layer 5 is formed by providing components such as components 52 and 53 on a sealing resin layer 51. The component built-in layer 5 is provided with an interlayer connection conductor (via conductor) 54 formed by filling with a conductive paste, via fill plating, or the like as necessary.

  The resin layer 51 is made of, for example, a thermosetting resin. Each component such as the components 52 and 53 is a chip of an electronic circuit element such as a capacitor, a coil, or a transistor, and has electrodes (external electrodes) 521 and 531 at the left and right ends. Examples of the thermosetting resin include an epoxy resin, a phenol resin, and a cyanate resin.

  The connection layer 4 includes a resin layer 41 similar to the resin layer 51, and is formed by providing an interlayer connection conductor 42 having a via structure at a necessary portion of the resin layer 41. The connection layer 4 is formed on the cured component built-in layer 5. The terminal electrode layer 3 is affixed. The core substrate 7 is formed of resin, ceramic, or the like, and is formed by providing an interlayer connection conductor 71 having a via structure at a necessary location.

  The wiring layers 6 and 8 are formed by, for example, laser processing or etching processing of copper foil according to a wiring pattern. The terminal electrode layer 3 is provided on one main surface of the connection layer 4, and is formed by, for example, laser processing or etching processing of a copper foil according to a wiring pattern. Then, the end faces of the interlayer connection conductors 42, 54, 71 are formed on the lands or pads formed as the wiring layers 6, 8 and the terminal electrode layer 3 by forming an alloy or an intermetallic compound, or in physical contact. As a result, the wiring layers 6 and 8 and the terminal electrode layer 3 are connected.

  The resist layer 2 is provided so as to partially cover the terminal electrode layer 3 by exposing a portion of the terminal electrode layer 3 that needs to be soldered. Further, the resist layer 2 is formed of, for example, a thermosetting epoxy resin so as to prevent unnecessary solder from adhering to the terminal electrode layer 3 by covering a portion of the terminal electrode layer 3 that does not require soldering. In addition, the material for forming the resist layer 2 is not limited to the above-described material, and various changes are made, for example, by using glass according to the type of the connection layer 4 (support substrate 9) on which the terminal electrode layer 3 is provided. be able to.

  Next, an outline of an example of a method for manufacturing the component built-in module 1 of FIG. 1 will be described. First, the components 52 and 53 are mounted on the core substrate 7 provided with the wiring layers 6 and 8 on both sides. Then, after filling the uncured resin layer 51 so as to fill the parts 52 and 53 and heat-curing, via holes are formed in the cured resin layer 51.

  Next, an uncured connection layer 4 is prepared, and via holes are also formed in the connection layer 4. Then, the via holes in the resin layer 51 (component built-in layer 5) and the connection layer 4 are filled with a conductive paste or subjected to via fill plating to form the interlayer connection conductors 42 and 54.

  Subsequently, a copper foil is attached to the connection layer 4, and the terminal electrode layer 3 is formed by etching or the like. Then, resist layer 2 is formed on connection layer 4 so as to cover the peripheral portion of terminal electrode layer 3 formed on one main surface of connection layer 4 except for a part thereof.

  Thereafter, the electronic component IC is mounted on the wiring layer 8 of the core substrate 7 via solder bumps, whereby the component built-in module 1 is completed.

  As described above, the support substrate 9 having the connection layer 4 and the component built-in layer 5 is formed, and the circuit substrate 10 is constituted by the resist layer 2, the terminal electrode layer 3, the support substrate 9 and the wiring layer 6. The terminal electrode layer 3 constitutes an external electrode that connects the circuit board 10 to the mother board.

  Next, a configuration in which the resist layer 2 covers the peripheral portion 31 of the terminal electrode layer 3 will be described with reference to FIG. FIG. 2 is a bottom view of FIG. 1 and shows a state in which the resist layer 2 covers the peripheral portion 31 of the terminal electrode layer 3.

  As shown in FIG. 2, the resist layer 2 continuously covers a portion of the peripheral portion 31 of the rectangular terminal electrode layer 3 except for a portion parallel to one edge 91 of the support substrate 9. Is provided. The resist layer 2 has an X- and Y-axis of the XY coordinate axis where the overlapping portion 21 of the terminal electrode layer 3 and the resist layer 2 has one point on the terminal electrode layer 3 excluding the peripheral portion 31 as an origin. It is provided so as to include at least three of the intersections between each and the peripheral end 33 of the terminal electrode layer 3. Further, the resist layer 2 is provided so as to cover all the corners 32 of the terminal electrode layer 3.

  Therefore, according to this embodiment, the peripheral portion 31 of the terminal electrode layer 3 provided on one main surface of the support substrate 9 is continuously covered with the resist layer 2 except for a part thereof, and the terminal The overlapping portion 21 of the electrode layer 3 and the resist layer 2 has an X- and Y-axis axes of the X-Y coordinate axis and the periphery of the terminal electrode layer 3 with one point on the terminal electrode layer 3 excluding the peripheral portion 31 as the origin. Since the resist layer 2 is provided so as to include at least three of the intersections with the end 33, the terminal electrode layer 3 is efficiently pressed into the support substrate 9 by the resist layer 2, and the terminal electrode layer 3 is supported. The bonding with the substrate 9 is reinforced, and for example, the terminal electrode layer 3 is prevented from being peeled from the support substrate 9 when a mechanical impact is applied to the component built-in module 1.

  Further, when the thermal expansion coefficients of the support substrate 9, the terminal electrode layer 3 and the resist layer 2 are greatly different, for example, the support substrate 9, the terminal electrode layer 3 and the resist layer 2 are heated and expanded during reflow. Even if stress is generated by the above, a part of the peripheral portion 31 of the terminal electrode layer 3 is not covered with the resist layer 2, so that the generated stress escapes from the portion of the terminal electrode layer peripheral portion 31 that is not covered with the resist layer 2. . Therefore, even if a stress that may damage the circuit board 10 due to heating during reflow or the like occurs, the terminal electrode layer 3 is prevented from being peeled off or cracked from the support substrate 9. Therefore, when a mechanical shock is applied to the component built-in module 1 or the component built-in module 1 is heated, the terminal electrode layer 3 provided on the support substrate 9 is prevented from being damaged, and the component built-in is prevented. The reliability of the module 1 (circuit board 10) is improved.

  Further, since the peripheral portion 31 of the terminal electrode layer 3 excluding the edge 91 side of the support substrate 9 is continuously covered with the resist layer 2, the circuit substrate 10 is heated at the time of reflow, for example. 9. Even if stress that may damage the circuit board 10 due to expansion of the terminal electrode layer 3 and the resist layer 2 occurs, the peripheral portion 31 of the terminal electrode layer 3 is not covered with the resist layer 102. It will escape from the edge 91 side of the support substrate 9. Therefore, a structure in which stress (strain) generated by expansion of each material forming the support substrate 9, the terminal electrode layer 103 and the resist layer 102 escapes from the edge 91 of the support substrate 9 to the outside of the support substrate 9. Therefore, damage to the terminal electrode layer 3 provided on the support substrate 9 can be prevented.

  In addition, since all the corners 32 of the terminal electrode layer 3 are covered with the resist layer 2, the corners 32 that are corner portions of the terminal electrode layer 3 that easily peel off from the support substrate 9 are covered with the resist layer 2. It is possible to further reliably prevent the terminal electrode layer 3 from being peeled from the support substrate 9 by being surely pressed against the support substrate 9.

Second Embodiment
Next, a second embodiment of the component built-in module 1 will be described with reference to FIG. FIG. 3 is a bottom view showing a second embodiment of the component built-in module 1 of FIG.

  The second embodiment is different from the first embodiment described above in that a plurality of terminal electrode layers 103 are formed in an island shape along the edge 91 of one main surface of the support substrate 9 as shown in FIG. It is a point provided. The resist layer 102 is provided so as to cover between the terminal electrode layers 103 on the main surface of the support substrate 9 and the central portion of the main surface. The resist layer 2 is provided so as to cover the peripheral portion of the terminal electrode layer 103 excluding the end 91 side of the support substrate 9 among the entire peripheral portion. Since the other configuration is the same as that of the first embodiment described above, the description of the configuration is omitted by attaching the same reference numerals.

  According to the second embodiment, the same effects as those of the first embodiment described above can be obtained, and the following effects can be obtained. That is, a plurality of terminal electrode layers 103 are provided in an island shape along the edge 91 of the main surface of the support substrate 9, and each terminal electrode layer 103 on the main surface of the support substrate 9 on which the terminal electrode layer 103 is provided. The middle and middle portions are covered with a resist layer 102. Therefore, for example, at the time of reflow, there is no possibility that the solder melted by the resist layer 102 provided between the terminal electrode layers 103 short-circuits the terminal electrode layers 103, and a plurality of island electrodes are provided on the support substrate 9. A short circuit between the terminal electrode layers 103 can be reliably prevented.

<First Modification>
Next, a first modification of the component built-in module 1 will be described with reference to FIG. FIG. 4 is a bottom view showing a first modification of the component built-in module 1 of FIG.

  This first modification differs from the second embodiment described above in that the resist layer 112 is aligned with the boundary of the terminal electrode layer 113 on the edge 91 side of the support substrate 9 as shown in FIG. Further, it is provided so as to cover between the terminal electrode layers 113 on the main surface of the support substrate 9 and the central portion of the main surface. Since the other configuration is the same as that of the second embodiment described above, description of the configuration is omitted by attaching the same reference numerals.

  According to this first modification, the same effects as those of the first and second embodiments described above can be obtained.

<Second Modification>
Next, a second modification of the component built-in module 1 will be described with reference to FIG. FIG. 5 is a bottom view showing a second modification of the component built-in module 1 of FIG.

  The second modification differs from the second embodiment described above in that the terminal electrode layer 123 is supported so that the boundary of the terminal electrode layer 123 is aligned with the edge 91 of the support substrate 9 as shown in FIG. This is a point provided on the substrate 9. Then, the resist layer 122 is provided so as to cover up to the edge 91 of the support substrate 9 so as to cover between the terminal electrode layers 123 on the main surface of the support substrate 9 and the central portion of the main surface. Since the other configuration is the same as that of the second embodiment described above, description of the configuration is omitted by attaching the same reference numerals.

  According to the second modification, the same effects as those of the first and second embodiments described above can be obtained.

<Modification of terminal electrode layer>
Next, a modified example of the terminal electrode layers 3, 103, 113, 123 will be described with reference to FIG. FIGS. 6A to 6B are diagrams showing modifications of the terminal electrode layers 3, 103, 113, and 123.

  As shown in FIG. 6A, the terminal electrode layer 133 is formed in a circular shape. Then, the resist layer 132 is such that the overlapping portion of the terminal electrode layer 133 and the resist layer 132 has an X-Y coordinate axis and a Y-axis with one point on the terminal electrode layer 133 excluding the peripheral portion as the origin. The terminal electrode layer 133 is provided so as to include at least three of the intersections with the peripheral edge.

  As shown in FIG. 6B, the terminal electrode layer 143 is formed in a circular shape with a part cut away. Then, the resist layer 142 is such that the overlapping portion of the terminal electrode layer 143 and the resist layer 142 has a point on the terminal electrode layer 143 excluding the peripheral portion as the origin, the X axis of the XY coordinate axis, and the Y axis respectively. The terminal electrode layer 143 is provided so as to include at least three of the intersections with the peripheral edge. Further, the resist layer 142 is provided so as to cover all corners of the terminal electrode layer 143.

  As shown in FIG. 6C, the terminal electrode layer 153 is formed in a line shape. Then, the resist layer 152 has a portion where the terminal electrode layer 153 and the resist layer 152 overlap with each other on the X- and Y-axes of the XY coordinate axes with one point on the terminal electrode layer 153 excluding the peripheral portion as the origin. The terminal electrode layer 153 is provided so as to include at least three of the intersections with the peripheral edge.

<Others>
The present invention is not limited to the above-described embodiment, and various modifications other than those described above can be made without departing from the spirit thereof, for example, the terminal electrode layers 3, 103, Of the peripheral portions of 113, 123, 133, 143, and 153, the portions that are not covered by the resist layers 2, 102, 112, 122, 132, 142, and 152 are not limited to the edge 91 side of the support substrate 9. Further, it is not necessary that all corner portions of the terminal electrode layers 3, 103, 113, 123, 133, 143, and 153 are covered with the resist layers 2, 102, 112, 122, 132, 142, and 152.

  Further, each component of the component built-in layer 5 may have any shape and size, and the number thereof may be any. Further, the resin layer 51 and the like may be formed of a photocurable resin or the like. Further, the support substrate 9 may be a single layer or multilayer substrate of resin or ceramic, and the terminal electrode layers 3, 103, 113, 123, 133, 143, and 153 may be provided on both surfaces of the support substrate 9. The present invention can be applied to various circuit boards.

2,102,112,122,132,142,152 Resist layer 21 Polymerized portion 3,103,113,123,133,143,153 Terminal electrode layer 31 Peripheral part 32 Corner part 33 Peripheral end 9 Support substrate 10 Circuit board

Claims (4)

A support substrate;
A terminal electrode layer provided on at least one main surface of the support substrate;
A resist layer partially covering the terminal electrode layer,
The circuit board, wherein the resist layer is provided so as to continuously cover the peripheral portion of the peripheral portion of the terminal electrode layer excluding at least one end side of the support substrate.   In the resist layer, the terminal portion of the terminal electrode layer and the resist layer is an X- and Y-axis axes of the X- and Y-coordinate axes with one point on the terminal electrode layer excluding the peripheral portion as the origin, and the terminal The circuit board according to claim 1, comprising at least three points of intersections with the peripheral edge of the electrode layer. A plurality of the terminal electrode layers are provided in an island shape along an edge of the main surface,
The circuit board according to claim 1, wherein the resist layer is provided so as to cover the terminal electrode layers of the main surface and a central portion of the main surface.   The circuit board according to claim 1, wherein the resist layer is provided so as to cover all corners of the terminal electrode layer.

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