JP2012124397A - Multilayer printed wiring board with built-in component - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a multilayer printed wiring board with built-in component in which an electronic component is embedded in the inner layer by an embedding resin, where formation of even a slight void under the built-in component can be prevented.SOLUTION: In the multilayer printed wiring board with built-in component in which an electronic component having more than one external electrode terminal is embedded in the inner layer by an embedding resin, a spacer is placed under the electrode terminal of the electronic component.

Description

  The present invention relates to a component-embedded multilayer printed wiring board in which an electronic component is embedded in an inner layer with a resin, and more particularly to a component-embedded multilayer printed wiring board that improves the embedding property of the electronic component.

  As electronic devices have become slimmer in recent years, there is a growing need for component-embedded multilayer printed wiring boards with electronic components embedded in the inner layer, but when embedded electronic components are embedded, embedded resin does not enter under the electronic components. In some cases, voids (voids having no resin in the inner layer) were generated.

  If a void exists under the electronic component on the component-embedded board with the electronic component embedded in the inner layer, the solder of the built-in component is remelted by the heat of reflow during surface mounting, causing a short circuit through the void was there.

  In addition, a slight void has an effect on the reliability of the substrate, such as the volume expanding due to heat during reflow and causing the delamination between the electronic component and the embedded resin due to the void.

  FIG. 7 shows one conventional example.

  In FIG. 7, P7 is an electronic component built-in portion of a component built-in type multilayer printed wiring board, and includes a support 71, a conductor pattern 72 disposed on the surface of the support 71, and solder 77 on the conductor pattern 72. An electronic component 74 mounted via the solder, a solder 77 connecting the electronic component 74 to the conductor pattern 72, a solder resist 73 disposed around or on the conductor pattern 72, And an embedded resin 78 in which the electronic component 74 is embedded in the printed wiring board P7. The electronic component 74 includes an electronic component main body 75 and electrode terminals disposed on both ends of the electronic component main body 75, respectively. 76.

  In FIG. 7, the solder resist 73 is provided with an opening on a part or all of the conductor pattern 72 to provide a component mounting pad (footprint) and to protect a region other than the opening from the solder 77. However, the gap 701 between the electronic component main body 75 and the solder resist 73 cannot be controlled due to variations in the amount of solder 77 manufactured, variations in mounting accuracy of the electronic component 74, and the like. The gap 701 becomes too narrow, and a part of a relatively large filler among the fillers contained in the embedding resin 78 cannot enter the gap 701, and as a result, a void is generated under the electronic component 74.

  Thus, a method as shown in FIG. 8 (for example, Patent Document 1) has been proposed.

  In FIG. 8, P8 is an electronic component built-in portion of a component built-in type multilayer printed wiring board, and includes a support 81, a conductor pattern 82 disposed on the surface of the support 81, and a solder 87 on the conductor pattern 82. The electronic component 84 mounted via the solder, the solder 87 connecting the electronic component 84 to the conductor pattern 82, the solder resist 83 disposed around or on the conductor pattern 82, And an embedded resin 88 in which the electronic component 84 is embedded in the printed wiring board P8. The electronic component 84 includes an electronic component body 85 and electrode terminals disposed at both ends of the electronic component body 85. 86. The solder resist 83 is divided into the solder resist 83 that divides the solder resist 83 at the approximate center between the electrode pads (conductor patterns) 82. Tsu Doo (grooves) 89 are formed.

  As shown in FIG. 8, since the slit 89 is provided in the solder resist 83 between the electrode pads (conductor patterns) 82, compared to the case where the slit 89 is not provided in the solder resist 83, the slit gap 802 is not formed. Although the embedding property of the embedding resin 88 is improved, similarly to the gap 701 of the conventional example shown in FIG. 7, the non-slit gap 801 is caused by the variation in the amount of solder 87 manufactured, the variation in mounting accuracy of the electronic component 84, and the like. The gap 801 becomes too narrow, and a part of the relatively large filler among the fillers contained in the embedding resin 88 cannot enter the gap 801. As a result, the electronic component 84 Actually, a slight void was generated underneath.

JP 2004-103988 A

  The present invention has been made in view of the above-mentioned problems and actual circumstances, and in a component-embedded multilayer printed wiring board in which an electronic component is embedded in an inner layer and embedded, a slight void is generated below the embedded electronic component. It is an object of the present invention to provide a component built-in type multilayer printed wiring board that can also be suppressed.

  As a result of various studies to solve the problem, the present inventor has found that a very good result can be obtained by arranging a spacer under the electrode terminal of the built-in electronic component, and the present invention has been completed. It was.

  That is, according to the present invention, in a component built-in type multilayer printed wiring board in which an electronic component having two or more electrode terminals is embedded in an inner layer with an embedding resin, a spacer is arranged below the electrode terminal of the electronic component. The above-described problems are solved by a component-embedded multilayer printed wiring board characterized by the above.

  Further, the present invention provides a component built-in type multilayer printed wiring board in which an electronic component having two or more electrode terminals is embedded in an inner layer with an embedding resin, and includes a conductor pattern for mounting the electronic component. The above-mentioned problems are solved by a component built-in type multilayer printed wiring board characterized in that a spacer is disposed between at least a part of the electrode terminals of the component and at least a part of the conductor pattern.

  In the present invention, the spacer preferably has a flat surface.

  In the present invention, the spacer is more preferably disposed on a solder resist.

  In the present invention, the spacer is more preferably formed of a solder resist.

  According to the present invention, since there is a spacer for securing a certain gap between the component mounting pad and the electrode terminal of the built-in electronic component, the embedded resin is filled under the built-in electronic component. As a result, it is possible to provide a component built-in type multilayer printed wiring board that can secure a necessary gap width and suppress the generation of slight voids under the electronic component.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic cross-sectional configuration diagram for explaining a first embodiment of a component built-in multilayer printed wiring board according to the present invention. FIG. 3 is a schematic cross-sectional configuration diagram for explaining a second embodiment of a component built-in multilayer printed wiring board according to the present invention. FIG. 6 is a schematic cross-sectional configuration diagram for explaining a third embodiment of a component built-in multilayer printed wiring board according to the present invention. The schematic cross section block diagram for demonstrating 4th Embodiment of the component built-in type multilayer printed wiring board of this invention. The schematic cross section block diagram for demonstrating 5th Embodiment of the component built-in type multilayer printed wiring board of this invention. The schematic cross section block diagram for demonstrating 6th Embodiment of the component built-in type multilayer printed wiring board of this invention. The schematic cross-section block diagram for demonstrating the conventional printed wiring board. The schematic cross-section block diagram for demonstrating another conventional printed wiring board.

  A first embodiment of the present invention will be described with reference to FIG.

  FIG. 1 is a schematic cross-sectional configuration diagram for explaining a first embodiment of a printed wiring board of the present invention. FIG. 1A is a schematic diagram of a component built-in multilayer printed wiring board P1 having electronic components therein. FIG. 4B is a schematic cross-sectional configuration diagram in which the electronic component built-in portion P11 of the component built-in type multilayer printed wiring board P1 shown in FIG.

  In FIG. 1, an electronic component built-in portion P11 includes a support body 1, a conductor pattern 2 embedded in the support body 1 so as to expose a joint surface with an electronic component 4, and a solder 7 on the conductor pattern 2. The electronic component 4 mounted via the solder, the solder 7 connecting the electronic component 4 to the conductor pattern 2, and the solder resist 3 (131 around the conductor pattern 2 or on the conductor pattern 2). 134) and the embedded resin 8 in which the electronic component 4 is embedded in the component built-in type multilayer printed wiring board P1, the electronic component 4 includes the electronic component main body 5 and the electronic component main body. 5 and electrode terminals 6 disposed at both ends.

  In the present embodiment, the role of the solder resist 3 varies depending on the position where it is disposed. The solder resists 131 and 132 function as spacers that are structural features of the present invention. Each solder resist located at 134 and 135 functions as a mask which is an original function of the solder resist.

  As shown in FIG. 1B, solder resists 131 and 132 are disposed as spacers between the electrode terminals 6 disposed on both ends of the electronic component 4 and the conductor pattern 2. It is preferable that the thickness of the solder resists 131 and 132 as the spacers is not less than the minimum distance necessary for solder mounting between the electrode terminal 6 and the conductor pattern 2.

  Thereby, the distance between the electronic component main body 5 and the solder resist 133 as a mask, that is, the width of the gap 101 can be formed wide.

  Therefore, even if there are variations in the amount of solder produced and variations in the mounting accuracy of electronic components, the gap becomes too narrow as in the conventional case, and the filler contained in the embedded resin is relatively large. A part of the gap cannot enter the gap, and a void is not generated under the electronic component. That is, since the width of the gap 101 is secured wide by the solder resists 131 and 132 as the spacers, the embedded resin 8 is surely filled in the gap 101 and the generation of slight voids can be suppressed. A built-in multilayer printed wiring board can be obtained.

  The variation in the amount of solder produced is, for example, due to unevenness, warpage, distortion, etc. of the substrate surface on the coated side (printed surface) in the solder coating process by the printing method. The interval between the printing surface and the printing surface varies depending on the printing position, and as a result, the solder coating amount varies depending on the location on the same printing surface.

  The variation in mounting accuracy of electronic components is, for example, a variation in positional accuracy that depends on the mechanical accuracy of the chip mounter. In addition to vertical and horizontal two-dimensional deviation from the design mounting position, Phenomenon such as three-dimensional displacement such as floating is shown compared to the other.

  Further, as shown in FIG. 1B, when the thickness of the solder resists 131 and 132 as the spacers is equal to the thickness of the solder resist 133 as the mask, the solder resist 133 as the mask, the electronic component main body 5 and , That is, the width of the gap 101 is equal to the thickness of the electrode terminal 6, so that the electrode terminal 6 preferably protrudes from the surface of the electronic component body 5, and further, the thickness of the electrode terminal 6 is It is desirable that the thickness be such that the width of the gap 101 necessary for filling the embedded resin 8 can be formed.

  For example, when the thickness of the electrode terminal 6 is 5 μm or more, the width of the gap 101 is also 5 μm or more, and a general embedded resin is filled without voids.

  The solder resists 131 and 132 as spacers have a fulcrum for maintaining a stable arrangement of the electronic component 4 in a region in contact with the electrode terminal 6 of the electronic component 4. When the electronic component 4 is arranged, the electronic component 4 can be prevented from being tilted and can be reliably arranged, and problems during mounting can be suppressed.

  Also, the solder resists 131 and 132 as spacers are made equal to each other, so that the mounted electronic component 4 is prevented from being tilted and reliable mounting is achieved, and the shape of the gap 101 is distorted. Therefore, the gap 101 is reliably filled with the embedded resin 8, and as a result, generation of slight voids under the electronic component 4 can be suppressed.

  Also, when mounting the electronic component 4, by applying an appropriate pressing pressure to such an extent that the solder resists 131 and 132 as spacers are not deformed, the amount of pressing into the electronic component 4 is controlled, and the electronic component 4 becomes inadvertent. Can prevent floating, avoiding problems associated with further thinning of recent multilayer printed wiring boards with built-in components, such as contact with the upper layer conductor pattern (not shown) of electronic component 4 and destruction of electronic component 4 I can do it.

  Also, the width of the gap 101 can be adjusted and changed by intentionally changing the thickness of the solder resists 131 and 132 as spacers and the thickness of the solder resist 133 as a mask.

  For example, when the thickness of the solder resists 131 and 132 as spacers is equal to the thickness of the solder resist 133 as a mask, the gap 101 is designed to have a thickness equal to the thickness of the electrode terminal 6, but a certain error occurs. At times, the material can be adjusted by adjusting either the thickness of the solder resists 131 and 132 as spacers, the thickness of the solder resist 133 as a mask, or both so as to absorb the difference due to the error. Further, it is possible to absorb a thickness error caused by manufacturing factors and to ensure the width of the design gap 101 and to suppress generation of a slight void under the electronic component 4 which is the object of the present invention. it can.

  As another example, the thickness of the solder resists 131 and 132 as spacers and the thickness of the solder resist 133 as a mask are intentionally changed to change the width of the gap 101 and are contained in the embedded resin 8 to be used. By obtaining an optimum width of the gap 101 in accordance with the diameter and shape of the filler used, it is possible to reduce the thickness of the component built-in multilayer printed wiring board P1 and to suppress the generation of slight voids under the electronic component 4. This makes it possible to easily cope with changes in the material of the embedded resin due to higher functionality and cost reduction.

  Further, when the surfaces of the solder resists 131 and 132 as spacers are flattened, when the electronic component 4 is arranged, more stable mounting becomes possible, and the occurrence of width variation in the gap 101 can be suppressed. Reliable filling is achieved, and the generation of voids can be further suppressed.

  Further, by further flattening the surface of the solder resist 133 as a mask and reducing an impediment to resin flow when filling the embedding resin 8, more reliable filling can be achieved and generation of voids can be further suppressed.

  Also, the solder resist as the spacer is not limited to one for each electrode terminal as shown in FIG. 1, and the number of solder resists may be increased for reasons such as improving the stability when mounting electronic components. I do not care.

  Similarly, the solder resist as the spacer is not limited to a specific shape, and the shape may be changed for the purpose of improving the stability when mounting electronic components.

  Next, a second embodiment of the present invention will be described with reference to FIG.

FIG. 2 is a diagram in which the electronic component built-in portion P11 shown in FIG. 1B is replaced in accordance with the contents of the second embodiment. FIG. 1 is used when explaining the first embodiment. The structure is substantially the same except for the electronic component built-in part P11 in (b) and the solder resist portion.
That is, in FIG. 2, the electronic component built-in portion P12 includes a support body 21, a conductor pattern 22 embedded in the support body 21 so as to expose a joint surface with the electronic component 24, and the conductor pattern 22 The electronic component 24 mounted on the solder 27 via the solder 27, the solder 27 connecting the electronic component 24 to the conductor pattern 22, and the solder resist disposed around or on the conductor pattern 22 23 (234 to 236) and the embedded resin 28 in which the electronic component 24 is embedded in the component built-in multilayer printed wiring board P1, the electronic component 24 includes the electronic component main body 25 and the electronic component 24. And electrode terminals 26 disposed at both ends of the component main body 25.

  In the present embodiment, the role of the solder resist 23 differs depending on the position where it is disposed. The solder resist located at 234 and 235 functions as a mask, and the solder resist located at 236 functions as a spacer. The solder resist structure differs from the electronic component built-in portion P11 of FIG. 1B used in describing the first embodiment.

  As shown in FIG. 2, in the electronic component 24, since the solder resist 236 is disposed between the electrode terminal 26 and the conductor pattern 22 disposed at both ends, the thickness of the solder resist 236 as the spacer and mask is concerned. Is preferably at least the distance necessary for solder mounting between the electrode terminal 26 and the conductor pattern 22. Thereby, the distance between the electronic component main body 25 and the solder resist 236 as a spacer and mask, that is, the width of the gap 201 can be formed wide.

  Furthermore, the solder resist 236 as a spacer and mask has an integrated structure straddling the two component mounting pads of the electronic component 24, and has a mask function as well as a spacer function. Unlike the electronic component built-in portion P11 of FIG. 1B used for describing the configuration, the gap 201 between the solder resist 236 and the electronic component 24 is composed of the electronic component main body 25, the electrode terminal 26, and the solder resist 236. A gap that is stable in shape.

  Thereby, the gap 201 has a shape in which the embedded resin 28 is more stably filled, and the generation of voids can be further suppressed.

  Therefore, even if there are variations in the amount of solder manufacturing, variations in the mounting accuracy of electronic components, etc., the width of the gap 201 is secured wide by the solder resist 236 as the spacer and mask, and the embedded resin 28 Since the shape is more stably filled, the embedded resin 28 is surely filled in the gap 201, and a component built-in type multilayer printed wiring board in which generation of slight voids is suppressed is obtained.

  The variation in the amount of solder produced is, for example, due to unevenness, warpage, distortion, etc. of the substrate surface on the coated side (printed surface) in the solder coating process by the printing method. The interval between the printing surface and the printing surface varies depending on the printing position, and as a result, the solder coating amount varies depending on the location on the same printing surface.

  The variation in mounting accuracy of electronic components is, for example, a variation in positional accuracy that depends on the mechanical accuracy of the chip mounter. In addition to vertical and horizontal two-dimensional deviation from the design mounting position, Phenomenon such as three-dimensional displacement such as floating is shown compared to the other.

  Further, when the surface of the solder resist 236 as a spacer and mask is flattened, more stable mounting is possible when the electronic component 24 is arranged, and the occurrence of variation in the width of the gap 201 can be suppressed, and the gap 201 can be suppressed. Since the resin flow inhibiting element of the embedding resin 28 filled in the inside can be reduced, more reliable filling can be achieved and the generation of voids can be further suppressed.

  As shown in FIG. 2, since the width of the gap 201 is equal to the thickness of the electrode terminal 26, it is desirable that the electrode terminal 26 protrudes from the surface of the electronic component main body 25. It is desirable that the thickness of the terminal 26 is equal to the width of the gap 201 necessary for filling the embedded resin 28.

  For example, if the thickness of the electrode terminal 26 is 5 μm or more, the width of the gap 201 is also 5 μm or more, and a general embedded resin is filled without voids.

  Next, a third embodiment of the present invention will be described with reference to FIG.

FIG. 3 is a diagram in which the component built-in part P11 shown in FIG. 1B is replaced in accordance with the contents of the third embodiment, and FIG. 1 (FIG. 1) used for explaining the first embodiment. The structure is substantially the same except for the electronic component built-in part P11 of b), the configuration position of the conductor pattern, and the solder resist portion.
That is, in FIG. 3, the electronic component built-in portion P <b> 13 includes a support 31, a conductor pattern 32 disposed on the support 31, and an electronic component mounted on the conductor pattern 32 via a solder 37. 34, solder 37 connecting the electronic component 34 to the conductor pattern 32, solder resist 33 (331 to 335) disposed around or on the conductor pattern 32, and the electronic component 34 Embedded resin 38 embedded in the component built-in type multilayer printed wiring board P1, and the electronic component 34 includes an electronic component main body 35 and electrodes disposed at both ends of the electronic component main body 35, respectively. And a terminal 36.

  In this embodiment, the solder resist 33 includes solder resists 331 and 332 that function as spacers, and solder resists 333, 334, and 335 that function as masks.

  In addition, regarding the conductor pattern, the electronic component built-in part P11 of FIG. 1B used when explaining the first embodiment and the electron of FIG. 2 used when explaining the second embodiment. The component built-in part P12 is a conductor pattern embedded in the support body so as to expose the joint surface with the electronic component, and is called a so-called coreless structure, whereas the third embodiment is different from the third embodiment. The electronic component built-in portion P13 shown in FIG. 3 used for the description has a so-called core structure in which a conductor pattern is arranged on the surface of the support.

  By the way, when the component mounting surface has a core structure like the electronic component built-in portion P13 of FIG. 3 used when explaining the third embodiment, the manufacturing method using a normal liquid type solder resist is used. Since the conductor pattern protrudes from the support 31 by the thickness of the conductor pattern, the solder resist follows the unevenness of the conductor pattern, and it is difficult to flatten the surface of the solder resist.

  Therefore, as the solder resist 33, a dry film-shaped solder resist protected by a cover film (not shown) is temporarily pressure-bonded by thermocompression bonding to the support 31 having irregularities of the conductor pattern using a vacuum laminator, By pressing with a flat hot press machine, the surface of the solder resist 33 can be flattened.

  Further, as the solder resist 33, a method in which a liquid solder resist is previously applied to the support 31 having irregularities of the conductor pattern and semi-cured, and then pressed by a flat hot press machine through a release film is used. May be.

  As shown in FIG. 3, since the surface of the solder resist 33 is flattened in the electronic component built-in part P13, even if there is a variation in the amount of solder manufacturing, a variation in the mounting accuracy of the electronic component, etc. The solder resists 331 and 332 as spacers ensure that the gap 301 is ensured more than the required width, and the width is uniform and uniform as a whole, and there is no variation in the width depending on the position in the gap 301. The embedded resin 38 is surely filled in the gap 301, and a component built-in type multilayer printed wiring board in which slight voids are suppressed is obtained.

  The variation in the amount of solder produced is, for example, due to unevenness, warpage, distortion, etc. of the substrate surface on the coated side (printed surface) in the solder coating process by the printing method. The interval between the printing surface and the printing surface varies depending on the printing position, and as a result, the solder coating amount varies depending on the location on the same printing surface.

  The variation in mounting accuracy of electronic components is, for example, a variation in positional accuracy that depends on the mechanical accuracy of the chip mounter. In addition to vertical and horizontal two-dimensional deviation from the design mounting position, Phenomenon such as three-dimensional displacement such as floating is shown compared to the other.

  Further, when the surfaces of the solder resists 331 and 332 as spacers are flattened, when the electronic component 34 is arranged, more stable mounting becomes possible, and the occurrence of variation in the width in the gap 301 can be suppressed. More reliable filling is achieved, and the generation of voids can be further suppressed.

  Further, by flattening the surface of the solder resist 333 and reducing an impediment to resin flow when filling the embedding resin 28, more reliable filling is achieved, and the generation of voids can be further suppressed.

  Also, the number of solder resists as spacers is not limited to one for each electrode terminal as shown in FIG. 3, but the number is increased for reasons such as improving the stability when mounting electronic components. It doesn't matter.

  Similarly, the solder resist as the spacer is not limited to a specific shape, and the shape may be changed for the purpose of improving the stability when mounting electronic components.

  As shown in FIG. 3, when the width of the gap 301 is equal to the thickness of the electrode terminal 36, it is desirable that the electrode terminal 36 protrudes from the surface of the electronic component main body 35. It is desirable that the thickness of 36 is equal to the width of the gap 301 necessary for filling the embedded resin 38.

  For example, when the thickness of the electrode terminal 36 is 5 μm or more, the width of the gap 301 is also 5 μm or more, and a general embedded resin is filled without voids.

  Next, a fourth embodiment of the present invention will be described with reference to FIG.

FIG. 4 is a diagram in which the electronic component built-in portion P11 shown in FIG. 1B is replaced in accordance with the contents of the fourth embodiment, and the third embodiment will be described with respect to the configuration position of the conductor pattern. 3 has substantially the same structure as that of the electronic component built-in portion P13 of FIG. 3 and the configuration of the solder resist is similar to that of the electronic component built-in portion P12 of FIG. 2 used to explain the second embodiment. This is the structure.
That is, in FIG. 4, the electronic component built-in portion P <b> 14 includes a support body 41, a conductor pattern 42 disposed on the support body 41, and an electronic component mounted on the conductor pattern 42 via solder 47. 44, solder 47 that connects the electronic component 44 to the conductor pattern 42, solder resist 43 (434 to 436) disposed around or on the conductor pattern 42, and the electronic component 44 Embedded in the printed wiring board P1, and the electronic component 44 includes an electronic component main body 45, and electrode terminals 46 disposed at both ends of the electronic component main body 45, It consists of

  In this embodiment, the role of the solder resist 43 differs depending on the position where it is disposed. The solder resist located at 434 and 435 functions as a mask, and the solder resist located at 436 functions as a spacer. It also has a function as a mask.

  The conductor pattern 42 has a core structure in which a conductor pattern is arranged on the surface of the support, similarly to the electronic component built-in part P13 of FIG. 3 used when explaining the third embodiment.

  As shown in FIG. 4, in the electronic component 44, since the solder resist 436 is disposed between the electrode terminal 46 and the conductor pattern 42 disposed at both ends, the size of the gap 401 is a certain width or more. Furthermore, the solder resist 436 has an integrated structure straddling the two component mounting pads of the electronic component 44, and functions as a spacer and mask, so that the gap 401 is formed between the electronic component main body 45 and the electrode. Surrounded by the terminal 46 and the solder resist 436, a gap that is stable in shape is formed.

  Therefore, in the electronic component built-in portion P14 having the gap 401, the embedding resin 48 is stably filled in the gap 401, and even if there is a variation in the amount of solder manufacturing, a variation in the mounting accuracy of the electronic component, etc. A component built-in type multilayer printed wiring board that suppresses generation of voids can be obtained.

  The variation in the amount of solder produced is, for example, due to unevenness, warpage, distortion, etc. of the substrate surface on the coated side (printed surface) in the solder coating process by the printing method. The interval between the printing surface and the printing surface varies depending on the printing position, and as a result, the solder coating amount varies depending on the location on the same printing surface.

  The variation in mounting accuracy of electronic components is, for example, a variation in positional accuracy that depends on the mechanical accuracy of the chip mounter. In addition to vertical and horizontal two-dimensional deviation from the design mounting position, Phenomenon such as three-dimensional displacement such as floating is shown compared to the other.

  As in the third embodiment described above, a dry film-shaped solder resist protected by a cover film (not shown) is used as the solder resist 43, and a support having unevenness of the conductor pattern using a vacuum laminator. The surface of the solder resist 43 can be flattened by temporarily pressing the body 41 by thermocompression bonding and then pressing it with a flat hot press.

  Further, as the solder resist 43, a method in which a liquid solder resist is previously applied to the support 41 having the unevenness of the conductor pattern and semi-cured, and then pressed by a flat hot press machine through a release film is used. May be.

  Further, when the surface of the solder resist 436 as a spacer and mask is flattened, more stable mounting is possible when the electronic component 44 is placed, and the occurrence of variation in distance in the gap 401 can be suppressed, and the gap can be reduced. Since the resin flow-inhibiting element of the embedded resin 48 filled in 401 can be reduced, more reliable filling can be achieved and the generation of voids can be further suppressed.

  As shown in FIG. 4, since the width of the gap 401 is equal to the thickness of the electrode terminal 46, it is desirable that the electrode terminal 46 protrudes from the surface of the electronic component main body 45. It is desirable that the thickness of the terminal 46 be equal to the width of the gap 401 necessary for filling the embedded resin 48.

  For example, when the thickness of the electrode terminal 46 is 5 μm or more, the width of the gap 401 is also 5 μm or more, and a general embedded resin is filled without voids.

  Next, a fifth embodiment of the present invention will be described with reference to FIG.

  FIG. 5 is a diagram in which the electronic component built-in portion P11 shown in FIG. 1B is replaced in accordance with the contents of the fifth embodiment. The support 51 and the conductors arranged on the support 51 are shown in FIG. A pattern 52; an electronic component 54 mounted on the conductor pattern 52 via a solder 57; a solder 57 connecting the electronic component 54 to the conductor pattern 52; and the periphery of the conductor pattern 52 or the conductor pattern Solder resist 53 (531 to 535) disposed on 52, spacers 537 and 538 disposed on part of the solder resist 53, and the electronic component 54 are embedded in the component built-in multilayer printed wiring board P15. Embedded electronic 58, and the electronic component 54 includes an electronic component main body 55 and electrode terminals 56 disposed at both ends of the electronic component main body 55, respectively. In is configured.

  In the present embodiment, the role of the solder resist 53 differs depending on the position where it is disposed, and the solder resists located at 531 and 532 function as spacers, and the solder resists located at 533, 534, and 535 respectively. The resist functions as a mask which is the original function of the solder resist.

  Spacers 537 and 538 are disposed on the solder resists 531 and 532, respectively.

  The feature of the fifth embodiment is that spacers 537 and 538 are arranged on solder resists 531 and 532 as spacers, and by setting the two spacers 537 and 538 to appropriate thicknesses, the gap 501 The width can be increased, and as a result, the optimum width of the gap 501 can be obtained in accordance with the diameter and shape of the filler contained in the embedded resin 58 to be used.

  This makes it possible to reduce the thickness of the built-in component-type multilayer printed wiring board and suppress the generation of slight voids under the electronic component, and also to respond to changes in the material of the embedded resin due to higher functionality. It becomes easy.

  In order to make the width of the gap 501 appropriate, it is not limited to adjusting only the thickness of the spacers 537 and 538, and the thickness of the solder resists 531 and 532 as spacers may be adjusted. You may adjust with both the thickness of 537 and 538, and the thickness of the soldering resist 531 and 532 as a spacer.

  Further, when the solder resists 531 and 532 as spacers are arranged in the same process as the solder resists 533, 534 and 535 as masks, it is desirable to adjust only by the thickness of the spacers 537 and 538.

  Further, the number of spacers is not limited to one for each electrode terminal as shown in FIG. 5, and the number of spacers may be increased for reasons such as improving the stability when mounting electronic components. .

  Similarly, the spacer is not limited to a specific shape, and the shape may be changed for the purpose of improving stability when mounting electronic components.

  In addition, if the spacer satisfies the functions required for the spacer (the appropriate thickness, and the appropriate thickness can be maintained in the printed wiring board manufacturing process, etc.) It does not matter whether the solder resist (solder repelling) function is present or not.

  In addition, the spacer may be other than resin, such as metal, regardless of whether it is resin.

  In addition, when using a metal as a spacer, since it is necessary to maintain the function as a spacer, it does not need to be melted by the heat of reflow even at the time of reflow (joining process of electrode terminal and conductor pattern by solder melting). .

  In addition, the spacer can be arranged in advance on the electrode terminal of the electronic component.

  In addition, the spacer can be mounted when mounting the electronic component.

  In addition, as for the mounting method of the spacer at the time of electronic component mounting, the method is not limited as long as it can be appropriately mounted at a target place, but it is desirable to use a device with high mounting accuracy.

  The fifth embodiment has a so-called core structure in which a conductor pattern is arranged on the surface of a support, as in the third and fourth embodiments already described. In that case, as a solder resist, a solder resist in a dry film shape protected by a cover film (not shown) is temporarily press-bonded by thermocompression bonding to a support having irregularities of the conductor pattern using a vacuum laminator. Then, a method of pressing with a flat hot press machine may be used, and as a solder resist, a liquid solder resist is previously applied to a support having irregularities of the conductor pattern and semi-cured, and then released. You may use the method of pressing with a plane hot press machine through a film.

  Further, when the surfaces of the spacers 537 and 538 are flattened, more stable mounting is possible when the electronic component 54 is arranged.

  When the width of the gap 501 is equal to the thickness of the electrode terminal 56, it is desirable that the electrode terminal 56 protrudes from the surface of the electronic component main body 55. Furthermore, the thickness of the electrode terminal 56 is made of embedded resin. It is desirable to be equal to the width of the gap 501 required to fill 58.

  For example, when the thickness of the electrode terminal 56 is 5 μm or more, the width of the gap 501 is also 5 μm or more, and a general embedded resin is filled without voids.

  Next, a sixth embodiment of the present invention will be described with reference to FIG.

  FIG. 6 is a diagram in which the component built-in part P11 shown in FIG. 1B is replaced in accordance with the contents of the sixth embodiment, and a support 61 and a conductor pattern disposed on the support 61 are shown. 62, an electronic component 64 mounted on the conductor pattern 62 via a solder 67, a solder 67 connecting the electronic component 64 to the conductor pattern 62, and the periphery of the conductor pattern 62 or the conductor pattern 62. The solder resist 63 (631 to 632) disposed above and an embedded resin 68 in which the electronic component 64 is embedded in the component built-in type multilayer printed wiring board P1, the electronic component 64 is an electronic component. The main body portion 65 and electrode terminals 66 arranged at both ends of the electronic component main body portion 65 are configured.

  In the present embodiment, spacers 631 and 632 arranged in a process different from the process of arranging the solder resist 63 are arranged inside the mounting pad in which the solder resist 63 is opened.

  A feature of the sixth embodiment is that spacers 631 and 632 arranged in a process different from the process of arranging the solder resist 63 are arranged on the mounting pad in which the solder resist 63 is opened. By setting two of 631 and 632 to appropriate thicknesses, the width of the opening 601 can be freely changed both large and small. As a result, the diameter and shape of the filler contained in the embedded resin 68 to be used Therefore, the optimum width of the gap 601 can be obtained.

  This makes it possible to reduce both the thickness of the component-embedded multilayer printed wiring board and the suppression of the generation of slight voids under the electronic components. Correspondence becomes possible.

  Here, the spacers 631 and 632 satisfy the functions required as the spacers (the appropriate thickness and the appropriate thickness can be maintained in the printed wiring board manufacturing process, etc.). If it is a thing, it does not ask | require the presence or absence of a soldering resist (solder repelling) function.

  In addition, the spacers 631 and 632 may be other than resin, such as metal, regardless of whether it is resin.

  In addition, when a metal is used as the spacers 631 and 632, it is necessary to maintain the function as a spacer. Therefore, even when reflow (joining process of the electrode terminal and the conductor pattern by melting the solder) is not melted by the heat of reflow. Although it is necessary, if a metal that does not melt is used for the spacers 631 and 632, the metal particles create a very uniform thickness, so that the width accuracy of the gap 601 can be further improved.

  For example, in FIG. 6, if a solder material containing metal particles whose particle size is adjusted and is not dissolved by heat during reflow is used as the spacers 631 and 632, the metal particles are deformed even when the electronic component 64 is mounted. Since it is difficult to raise, the accuracy as a spacer (having a height adjusting function) can be improved, and as a result, the width accuracy of the gap 601 can be improved.

  In addition, if a solder material containing metal particles whose particle size is adjusted and is not dissolved by heat during reflow is used for the spacers 631 and 632, compared to the case of using a non-metallic material (non-conductive material). The metal ratio between the conductor pattern 62 and the electrode terminal 66 is increased, and as a result, the conductivity can be improved.

  In addition, the spacer can be arranged in advance on the electrode terminal of the electronic component.

  In addition, the spacer can be mounted on a mounting pad when the electronic component is mounted.

  In addition, as for the mounting method of the spacer at the time of electronic component mounting, the method is not limited as long as it can be appropriately mounted at a target place, but it is desirable to use a device with high mounting accuracy.

  The number of spacers is not limited to two as shown in FIG. 6 (one for each electrode terminal), but the number of spacers is increased for reasons such as improving the stability when mounting electronic components. It doesn't matter.

  Similarly, the spacer is not limited to a specific shape, and the shape may be changed for the purpose of improving stability when mounting electronic components.

  The sixth embodiment has a so-called core structure in which a conductor pattern is arranged on the surface of a support, as in the third and fourth embodiments already described. Also good.

  Further, when the surfaces of the spacers 631 and 632 are flattened, more stable mounting is possible when the electronic component 64 is disposed.

  As shown in FIG. 6, when the thickness of the spacers 631 and 632 is equal to the thickness of the solder resist 63, the distance between the solder resist 63 and the electronic component main body 65, that is, the width of the gap 601 is determined by the electrode terminal 66. Therefore, it is desirable that the electrode terminal 66 protrude from the surface of the electronic component main body 65, and further, the thickness of the electrode terminal 66 is a gap 601 necessary for filling the embedded resin 78. It is desirable that the thickness is such that a width can be formed.

  For example, when the thickness of the electrode terminal 66 is 5 μm or more, the width of the gap 601 is also 5 μm or more, and a general embedded resin is filled without voids.

  The electronic components used in the description of the above-described six embodiments are, for example, surface mount type passive components (resistors, capacitors, inductors, etc.) that generally have two electrodes, and a silicon wafer. This refers to all electronic parts having two or more electrode terminals outside, such as a bare chip having a functional body (circuit) and a molded IC package in which the bare chip is sealed with resin. It is not limited in scope or type.

  In the description of the present invention, the above-described six embodiments have been described as examples. However, the configuration of the present invention is not limited to these, and is not limited to these examples, and the scope of the present invention is not limited. Various modifications can be made within.

  Hereinafter, examples, comparative examples, and test examples will be further described.

Example 1
First, after preparing copper foil and applying a solder resist (PSR4000 AUS320: manufactured by Taiyo Ink Co., Ltd.) as a spacer and mask, it was exposed, developed, and cured to form a mounting pad.

  Next, mounting was performed using a multilayer ceramic capacitor (GRM1552C1H330JA01: manufactured by Murata Manufacturing Co., Ltd.) and using solder (M-705-BKC10: manufactured by Senju Metal Co., Ltd.) as a connection material.

  Next, a high-temperature vacuum lamination press was performed using an embedded resin material corresponding to FR-4 containing a filler having an average particle size of 0.5 to 1.0 μm.

  Next, through-hole drilling, plating, and circuit formation were performed, and stacking pretreatment was performed.

  Next, lamination was performed again using the build-up material, and laser hole machining, plating, circuit formation, and solder resist were applied to obtain a component built-in type multilayer printed wiring board having an electronic component built-in portion shown in FIG. In the obtained printed wiring board, 30% (0.06 mm) of the electrode terminals are held by spacers in the length direction, and 13% (0.05 mm) are held at both ends with respect to the electrode terminals in the width direction. It was something.

Comparative Example 1
A component built-in type multilayer printed wiring board having an electronic component built-in portion shown in FIG. 8 was obtained in the same manner as in Example 1 except that a solder resist as a spacer was not applied to the lower portion of the electrode terminal.

Test example 1
When the cross-sectional gap between the electronic component of the printed wiring board obtained in Example 1 and the solder resist was measured, the width was in the range of 14.8 to 17.1 μm.
On the other hand, when the cross-sectional gap between the electronic component of the printed wiring board obtained in Comparative Example 1 and the solder resist was measured, the width was in the range of 0.0 to 22.7 μm.
From the above, it was confirmed that according to the present invention, the gap can be secured widely and evenly.

Test example 2
When the cross section under the electronic component of the printed wiring board obtained in Example 1 was observed at 99 points, the number of voids was 0, and it was confirmed that no voids were generated.
On the other hand, when the cross section under the electronic component of the printed wiring board obtained in Comparative Example 1 was similarly observed, the number of voids was 8.
From the above, according to the present invention, it was confirmed that the resin fluidity was improved and the generation of slight voids under the built-in components could be suppressed.

1, 21, 31, 41, 51, 61, 71, 81: Supports 2, 22, 32, 42, 52, 62, 72, 82: Conductor patterns 3, 23, 33, 43, 53, 63, 73, 83: Solder resist 4, 24, 34, 44, 54, 64, 74, 84: Electronic component 5, 25, 35, 45, 55, 65, 75, 85: Electronic component main body 6, 26, 36, 46, 56, 66, 76, 86: Electrode terminals 7, 27, 37, 47, 57, 67, 77, 87: Solder 8, 28, 38, 48, 58, 68, 78, 88: Embedded resin 101, 201, 301 , 401, 501, 601, 701, 801: gaps 131, 132, 331, 332, 531, 532: solder resists 133, 134, 135, 234, 235, 333, 334, 335, 43 as spacers , 435, 533, 534, 535: Solder resist 236, 436 as a mask: Solder resist 537, 538, 731, 732: Spacer 801: Non-slit gap 802: Slit gap 89: Slit P1: Print wiring Plates P11, P12, P13, P14, P15, P16, P7, P8: Electronic component built-in part

Claims (5)

  In a component built-in type multilayer printed wiring board in which an electronic component having two or more electrode terminals is embedded in the inner layer with an embedding resin, a spacer is arranged below the electrode terminal of the electronic component. Component built-in type multilayer printed wiring board.   In a component built-in type multilayer printed wiring board in which an electronic component having two or more electrode terminals on the inner layer is embedded in the inner layer with an embedded resin, a conductor pattern for mounting the electronic component is provided, and the electronic component A component built-in multilayer printed wiring board, wherein a spacer is disposed between at least a part of the electrode terminals and at least a part of the conductor pattern.   The component built-in multilayer printed wiring board according to claim 1, wherein the spacer has a flat surface.   The component built-in multilayer printed wiring board according to claim 1, wherein the spacer is disposed on a solder resist.   The component built-in multilayer printed wiring board according to claim 1, wherein the spacer is made of a solder resist.