JP5480195B2 - Component mounting board - Google Patents

Description

  The present invention relates to a component mounting board.

  In recent years, a semiconductor substrate is manufactured by mounting an IC chip on a wiring board formed by laminating at least one conductor layer and an insulating layer, so-called resin wiring board or ceramic board, and sealing the resin. There is a lot going on.

  The IC chip is electrically connected via a terminal pad forming the substrate surface and a plurality of bumps formed on each of the plurality of terminal pads of the IC chip mounting portion. On the other hand, external terminals are formed on the back side of the wiring board to be electrically connected to the base board or inserted into a socket for electrical connection.

  In the semiconductor package as described above, components such as capacitors and resistors for supplying power to the IC chip are electrically connected to the terminal pads of the wiring board via a plurality of bumps on the same substrate surface as the IC chip. In many cases, it is formed so as to be connected.

  When such a semiconductor package is used, the IC chip or component mounted on the substrate generates heat, so that the IC chip or component is repeatedly heated and cooled by repeated use of the semiconductor package. As a result, bumps that connect IC chips and components to terminal pads on the surface of the substrate expand or partially dissolve. Especially, in bumps of components that are smaller than IC chips, adjacent bumps are combined, There may be a short circuit.

  Therefore, when a structure in which an IC chip or a component is mounted on the substrate surface is resin-sealed and configured as a semiconductor package, the top surface and side surfaces of the IC chip and component are covered with resin and embedded. In particular, it is required to inject a resin also into the lower surface side of the component and to prevent the bumps holding the electronic component from being joined and short-circuited by the injected resin.

  However, when the resin is supplied using a dispenser or the like and the resin is sealed by this, the resin cannot be sufficiently injected into the lower surface side of the component, and the lower surface side of the component is filled. In some cases, voids are generated in the resin. When this void becomes a certain size, a region where no resin exists between adjacent bumps is formed, and the bumps are partially coupled through the region as described above, resulting in a short circuit. There is. Therefore, when manufacturing a semiconductor package by sealing with resin, it is necessary to sufficiently inject and fill the resin on the lower surface side of the component so as not to generate voids.

  In view of such a problem, in Patent Document 1, a groove having a uniform width is formed in the length direction of the component at a position on the surface of the substrate facing the component, and sufficient both resins are provided on the lower surface side of the component. Techniques for filling the are disclosed. Patent Documents 2 and 3 also disclose that a groove having a uniform width in the length direction of a component is formed at a position facing the component on the substrate surface, although the purpose is different.

  However, even with these techniques, it is not possible to fill a sufficient amount of resin on the lower surface side of the component, particularly the lower surface side of the central portion of the component. The formation of a non-existing region could not be sufficiently suppressed.

JP 2006-5112 A JP 2003-46216 A JP 2008-244044 A

  The present invention relates to a component mounting board in which a component is mounted via a terminal pad exposed on the surface of the wiring board, and a sufficient amount of sealing resin is injected and filled between the wiring board surface and the component, Even if this occurs, the object is to prevent the bumps holding the components from being combined and short-circuited.

In order to achieve the above object, the present invention provides:
A wiring board having a pair of terminal pads exposed on the substrate surface;
A component mounted on the pair of terminal pads,
A component mounting substrate filled with resin between the substrate surface and the component,
The substrate surface extends in a crossing direction between the pair of terminal pads and intersecting a first arrangement direction in which the terminal pads constituting the pair of terminal pads are arranged, and from the central portion toward both ends. A groove portion having a narrow width in the first arrangement direction is formed,
The center part of the said groove part is formed in the position corresponding to the center in the said cross direction of the said component, It is related with the component mounting board | substrate characterized by the above-mentioned.

  According to the present invention, the surface of the wiring board extends in a direction (crossing direction) intersecting with a direction defined by the pair of terminal pads (first arrangement direction in which the terminal pads constituting the pair of terminal pads are arranged). The groove portion is formed in such a manner that the center portion of the groove portion is positioned corresponding to the center portion of the component, and the groove portion is formed so that the width is narrowed from the center portion toward both ends. Yes.

  Since the groove portion is narrower at both ends than the center portion, for example, when a resin is injected and filled between the surface of the wiring board and the component using a dispenser, the resin is It will be introduced into the end portion where the width of the groove portion is initially narrowed. At this time, since the width of the central portion of the groove portion is larger than that of the end portion, the amount of the resin introduced into the end portion of the groove portion is increased from the end portion toward the central portion.

  Therefore, since the resin can fill a sufficient amount of resin between the substrate surface and the component, particularly between the substrate surface and the component center, through the groove portion, the substrate surface and the component can be filled. Even if a void occurs in the region between the center, the amount of resin filled between them increases, so that it is possible to prevent the bumps holding the components from being joined and short-circuited.

  In one example of the present invention, the side surface of the groove can be configured as a continuous surface. In this case, the flow resistance of the resin is further reduced. As a result, the resin can be introduced more quickly and smoothly to the center of the groove, and in particular, it can be introduced quickly and smoothly between the substrate surface and the center of the component. The amount of resin filled in can be increased sufficiently. Therefore, even if voids occur in the area between the substrate surface and the center of the component, the amount of resin filled between them increases sufficiently, so that the bumps holding the components are joined and short-circuited. It can prevent more effectively.

  In one example of the present invention, both end portions of the groove portion can be formed outward from the projection region of the component. In this case, since the end portion of the groove portion is exposed to the outside of the component, the resin can be easily introduced into the groove portion through the end portion, and as a result, the above-described effects are obtained. Can be played more remarkably.

  Furthermore, in an example of the present invention, the angle formed between the side surface and the bottom surface of the groove portion can be an obtuse angle. In this case, since the resin can be sufficiently introduced at the boundary portion between the bottom surface and the side surface of the groove, generation of voids at the boundary portion can be suppressed.

  Moreover, in an example of this invention, the shape in the one end side from the center part of a groove part and the shape in the other end side from a center part can be made the same. In this case, since a uniform amount of resin can be introduced from the end portions located on both sides of the groove portion to the central portion at a uniform speed, voids are generated in the region between the substrate surface and the component center. Can be suppressed.

  Furthermore, in an example of the present invention, the side surface of the groove can be a roughened surface. In this case, since the adhesion between the side surface of the groove and the resin injected into the groove is improved, even when a thermal history is applied to the groove, the solder flows between the groove and the resin. A short circuit between the bumps to be held can be prevented.

  As described above, according to the present invention, in a component mounting board in which components are mounted via terminal pads exposed on the wiring board surface, a sufficient amount of sealing is provided between the wiring board surface and the parts. Even if a void is generated by injecting and filling the resin, it is possible to prevent the bumps holding the components from being combined and short-circuited.

It is a top view of the component mounting board in an embodiment. It is sectional drawing at the time of cutting the component mounting board | substrate shown in FIG. 1 along the II line. It is a figure which expands and shows the part shown by the area | region A of the component mounting board | substrate shown in FIG. It is a figure which shows the state of the cross section of the groove part formed in the component mounting board | substrate shown in FIG. It is one process figure in the manufacturing method of the component mounting board | substrate in embodiment. Similarly, it is one process figure in the manufacturing method of the component mounting board in an embodiment. Similarly, it is one process figure in the manufacturing method of the component mounting board in an embodiment. Similarly, it is one process figure in the manufacturing method of the component mounting board in an embodiment. Similarly, it is one process figure in the manufacturing method of the component mounting board in an embodiment. Similarly, it is one process figure in the manufacturing method of the component mounting board in an embodiment. Similarly, it is one process figure in the manufacturing method of the component mounting board in an embodiment. Similarly, it is one process figure in the manufacturing method of the component mounting board in an embodiment. Similarly, it is one process figure in the manufacturing method of the component mounting board in an embodiment. Similarly, it is one process figure in the manufacturing method of the component mounting board in an embodiment.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

(Component mounting board)
FIG. 1 is a top plan view of a component mounting board in the present embodiment, FIG. 2 is a cross-sectional view taken along the line II of the component mounting board shown in FIG. 1, and FIG. It is a figure which expands and shows the part shown by the area | region A of the component mounting board | substrate shown in FIG. FIG. 4 is a diagram showing a cross-sectional state of the groove formed in the component mounting board shown in FIG.

  As shown in FIG. 2, the wiring board 10 constituting the component mounting board 1 of this embodiment includes a heat resistant resin plate (for example, bismaleimide-triazine resin plate) and a fiber reinforced resin plate (for example, glass fiber reinforced epoxy resin). It has the plate-shaped core 101 comprised by these.

  The plate-like core 101 is formed with a through-hole 111 drilled by a drill or the like, and a through-hole conductor 112 is formed on the inner wall surface thereof. Further, the through hole 111 is filled with a resin filling material 114 such as an epoxy resin.

  A core conductor layer M1 is formed on the front surface 101A of the plate-like core 101, and a core conductor layer M11 is formed on the back surface 101B of the plate-like core 101. The core conductor layers M1 and M11 are formed as a plane conductor pattern that covers most of the front surface 101A and the back surface 101B of the plate-like core 101, and are used as a power supply layer or a ground layer, as well as the first via pad 121 and the second via pad. 122 is configured.

  In the present embodiment, as shown in FIG. 2, a part of the first via pad 121 and the second via pad 122 is formed so as to be connected to the through-hole conductor 112.

  A first insulating layer 131 is formed on the surface 101A of the plate-shaped core 101 so as to cover the core conductor layer M1, and on the back surface 101B of the plate-shaped core 101, the core conductor layer M11 is covered. A second insulating layer 132 is formed.

  On the first insulating layer 131 and the second insulating layer 132, first conductor layers M2 and M12 are formed, respectively. The first conductor layers M2 and M12 constitute a wiring layer (wiring pattern) (not shown), and constitute a third via pad 123, a receiving pad 125, and a fourth via pad 124, respectively. The receiving pad 125 is used to prevent the irradiated laser beam from reaching the first insulating layer 131 located below when the groove 16 described below is formed by laser irradiation.

  A third insulating layer 133 and a fourth insulating layer 134 are formed on the first insulating layer 131 and the second insulating layer 132 so as to cover the first conductor layers M2 and M12, respectively. Yes.

  Further, second conductor layers M3 and M13 are formed on the third insulating layer 133 and the fourth insulating layer 134, respectively. The second conductor layers M3 and M13 constitute a wiring layer (wiring pattern) (not shown), and constitute a first metal pad (terminal pad) 141 and a second metal pad (terminal pad) 142, respectively.

  In addition, the first resist layer 161 and the second resist layer are formed on the third insulating layer 133 and the fourth insulating layer 134 so as to cover the first metal pad 141 and the second metal pad 142, respectively. 162 is formed. Note that openings 161A and 162A are formed in the first resist layer 161 and the second resist layer 162, respectively, and the first metal pad 141 and the second metal pad are formed through the openings 161A and 162A. 142 is exposed.

  Via holes 131A and 132A are formed in the first insulating layer 131 and the second insulating layer 132, respectively, and a first via conductor 151 and a second via conductor 152 are formed in these via holes, The first via pad 121 and the third via pad 123 and the second via pad 122 and the fourth via pad 124 are electrically connected.

  Via holes 133A and 134A are formed in the third insulating layer 133 and the fourth insulating layer 134, respectively, and a third via conductor 153 and a fourth via conductor 154 are formed in these via holes, The third via pad 123 and the first metal pad 141 and the fourth via pad 124 and the second metal pad 142 are electrically connected.

  The component 12 is mounted on the first metal pad 141 via the solder layer 18.

  As shown in FIGS. 1 and 2, the substrate surface 10 </ b> A composed of the surface of the resist layer 161 of the wiring substrate 10 and the surface of the first metal pad 141 exposed from the opening 161 </ b> A of the resist layer 161 is formed on the substrate surface 10 </ b> A. As described above, a plurality of components 12 are mounted via the first metal pads 141, and the semiconductor chip 11 is mounted at a substantially central portion thereof. The semiconductor chip 11 and the component 12 are electrically connected by a wiring pattern 15 constituted by the first metal pads 141.

  The second metal pad 142 formed so as to be exposed from the opening 162A of the second resist layer 162 on the back surface side of the wiring substrate 10 is a back surface land (for connecting the wiring substrate 10 to the mother board). LGA pad).

  The through-hole conductor 112, the core conductors M1 and M11, the first conductor layers M2 and M12, and the second conductor layers M3 and M13 can each be composed of a good electrical conductor such as gold, silver, or copper. Further, the first via conductor 151 to the fourth via conductor 154 can also be composed of good electrical conductors such as gold, silver, and copper. However, in general, it can be easily formed by a plating method and is made of copper because it is inexpensive.

  The first insulating layer 131 to the fourth insulating layer 134 can be made of, for example, a thermosetting resin.

  Further, the component 12 can be a passive component such as a capacitor or a resistor.

  As shown in FIGS. 2 and 3, in the wiring board 10 of the present embodiment, a pair of metal pads (terminals) for mounting the component 12 is provided below the component 12, that is, on the surface 10 </ b> A of the wiring substrate 10 facing the component 12. The center portion 16A of the groove portion 16 is located immediately below the center of the component 12 in the direction intersecting with the direction defined by the pad 141 (in this embodiment, the same as the direction defined by the pair of solder layers 18). Thus, the width is narrowed from the central portion toward both end portions, and the groove portion 16 is formed with a depth penetrating the first resist layer 161.

  The width of the groove portion 16 is narrowed from the central portion 16A toward the end portion 16B. When the resin is injected and filled between the surface 10A of the wiring board 10 and the component 12, for example, a dispenser is used. However, the resin is filled through the groove portion 16.

  Since the groove portion 16 is narrower at the end portion 16B than the central portion 16A, the resin is introduced into the end portion 16B where the width of the groove portion 16 is initially narrowed. At this time, since the width of the central portion 16A of the groove portion 16 is larger than that of the end portion 16B, the resin introduced into the end portion 16B of the groove portion 16 is filled as it goes from the end portion 16B to the central portion 16A. The amount increases.

  Therefore, since the resin is filled with sufficient resin between the substrate surface 10A and the center of the component 12 through the groove 16, even if voids are generated in the region between them, the component It is possible to prevent the solder layers (bumps) 18 holding 12 from being combined and short-circuited.

  Further, in this embodiment, since the side surface 16C of the groove portion 16 is configured as a continuous surface, the above-described resin flow resistance is further reduced, and the resin can be more quickly and quickly transferred to the central portion 16A of the groove portion 16. It can be introduced smoothly. As a result, even if voids are generated between the substrate surface 10A and the component 12, particularly in the region between the substrate surface 10A and the center of the component 12, the amount of resin filled between them is sufficiently large. Further, it is possible to more effectively prevent the solder layers (bumps) 18 holding the component 12 from being bonded to each other and short-circuiting.

  Furthermore, in the present embodiment, the end 16B of the groove 16 is positioned outward from the projection region of the component 12 on the substrate surface 10A, so that the end 16B is positioned outward of the component 12. become. Therefore, it becomes possible to easily introduce the resin into the groove portion 16 via the end portion 16B, and as a result, the above-described operational effects can be more remarkably exhibited.

  Moreover, in this embodiment, the shape in the one end side from the center part 16A of the groove part 16 and the shape in the other end side from the center part are made the same. That is, the shape of the end portion 16B of the groove portion 16 is the same. In this case, since a uniform amount of resin can be introduced into the central portion 16A from the end portions 16B located on both sides of the groove portion 16 at a uniform speed, the gap between the substrate surface 10A and the center of the component 12 is reduced. Generation of voids in the region can be suppressed.

  In the present embodiment, as shown in FIG. 4, the angle formed between the side surface 16C and the bottom surface 16D of the groove 16 can be an obtuse angle. In this case, since the resin can be sufficiently introduced at the boundary portion between the bottom surface 16D and the side surface 16C of the groove portion 16, generation of voids at the boundary portion can be suppressed.

  In the present embodiment, the side surface 16C of the groove 16 can be a roughened surface. In this case, since the adhesiveness between the side surface 16C of the groove 16 and the resin injected into the groove is improved, solder flows between the groove 16 and the resin even when a thermal history is applied to the groove 16. Therefore, short circuit between the solder layers (bumps) 18 holding the component 12 can be prevented.

  In order to make the side surface 16C of the groove portion 16 rough, a desmear treatment is performed after the groove portion 16 is formed by laser processing.

  The ratio of the width of the central portion 16A to the width of the end portion 16B of the groove portion 16 is not particularly limited as long as the above-described effects are achieved. For example, the width of the widest central portion 16A is “1”. In this case, the width of the narrowest end portion 16B can be in the range of 0.2 to 0.8. The specific width is determined in consideration of the size of the wiring board 10 and the size of the component 12. The depth of the groove 16 is determined depending on the laser irradiation output and the number of times of irradiation and the position where the receiving pad 125 is formed when the groove 16 is formed by laser irradiation.

(Manufacturing method of component mounting board)
Next, a method for manufacturing the component mounting board shown in FIGS. 5 to 14 are process diagrams in the manufacturing method in this example. In addition, the process drawing shown below shows the sequential process when it sees in the cross section at the time of cutting along the II line | wire of a wiring board equivalent to FIG.

  First, as shown in FIG. 5, a plate-shaped heat-resistant resin plate (for example, bismaleimide-triazine resin plate) or a fiber reinforced resin plate (for example, glass fiber reinforced epoxy resin) is prepared as a core substrate 101, and drilling, etc. The through hole 111 is drilled by this method. Next, as shown in FIG. 6, core conductor layers M <b> 1 and M <b> 11 are formed by pattern plating on the front surface 101 </ b> A and the back surface 101 </ b> B of the core substrate 101, and through-hole conductors 112 are formed in the through-holes 111. Is filled with a resin filling material 114.

  Next, after roughening the core conductor layers M1 and M11, as shown in FIG. 7, resin films are formed on the main surfaces 101A and 101B of the core substrate 101 so as to cover the core conductor layers M1 and M11. Are laminated and cured to obtain the first insulating layer 131 and the second insulating layer 132. The resin film may contain a filler as necessary.

  Next, as shown in FIG. 8, the first insulating layer 131 and the second insulating layer 132 are irradiated with laser from the surfaces thereof to form via holes 131A and 132A in a predetermined pattern. Roughening treatment is performed on the first insulating layer 131 and the second insulating layer 132 including 132A. Note that in the case where the first insulating layer 131 and the second insulating layer 132 include a filler, when the roughening treatment is performed on the first insulating layer 131 and the second insulating layer 132 as described above, Since the filler is liberated and remains on the first insulating layer 131 and the second insulating layer 132, water washing is appropriately performed to remove the liberated filler.

  Next, desmear treatment and outline etching are performed to clean the inside of the via holes 131A and 132A. In addition, in this example, since water washing is implemented, the aggregation of the said filler can be suppressed in the case of water washing in a desmear process.

  Moreover, in this example, an air blow can be performed between the water washing by the high water pressure mentioned above and the said desmear process. Thereby, even when the filler liberated by the water washing described above is not completely removed, the removal of the filler can be supplemented in the air blow.

  Next, as shown in FIG. 9, the first conductor layers M2 and M12 and the via conductors 151 and 152 are formed on the first insulating layer 131 and the second insulating layer 132 by pattern plating. The first conductor layer M2 and the like are formed as follows by a semi-additive method or the like. First, for example, after forming an electroless copper plating film on the first insulating layer 131 and the second insulating layer 132, a resist film is formed on the electroless copper plating film, and the resist is removed by photolithography. A formation part is formed and formed by performing electrolytic copper plating on the non-formation part of the resist. The resist can be peeled and removed with KOH or the like to form a patterned first conductor layer M2 or the like.

  Next, after roughening the first conductor layers M2 and M12, the first conductor layers M2 and M12 are formed on the first insulating layer 131 and the second insulating layer 132 as shown in FIG. The third insulating layer 133 and the fourth insulating layer 134 are formed by laminating and curing the resin film so as to cover the film. This resin film may also contain a filler as necessary, as described above.

  Next, as shown in FIG. 11, the third insulating layer 133 and the fourth insulating layer 134 are irradiated with laser from their surfaces to form via holes 133A and 134A in a predetermined pattern, and the via holes 133A and 134A are formed. A roughening process is performed on the third insulating layer 133 and the fourth insulating layer 134 including When the third insulating layer 133 and the fourth insulating layer 134 include a filler, when the roughening treatment is performed on the third insulating layer 133 and the fourth insulating layer 134 as described above, the filler Since it is liberated and remains on the third insulating layer 133 and the fourth insulating layer 134, water washing and air blowing are appropriately performed as described above. Next, the via holes 133A and 134A are subjected to desmear treatment and outer shape etching (outline etching) to clean the via holes 133A and 134A.

  Next, as shown in FIG. 12, the second conductor layers M3 and M13 are formed on the third insulating layer 133 and the fourth insulating layer 134 by pattern plating, and the via conductors 153 and 135 are formed in the via holes 133A and 134A. 154 is formed.

  Thereafter, as shown in FIG. 13, the first metal pad 141 and the second metal pad 142 in the second conductor layers M3 and M13 are exposed on the third insulating layer 133 and the fourth insulating layer 134. First resist layers 161 and 162 having such openings 161A and 162A are formed.

Next, as shown in FIG. 14, the surface of the third insulating layer 133 is partially irradiated with CO ₂ laser so as to penetrate the first resist layer 161. On the other hand, the groove 16 is formed. When forming the groove portion 16, the irradiation position of the CO ₂ laser spot is adjusted as appropriate so that the width increases from the center portion 16A toward the end portion 16B as shown in FIG. Form.

  As described above, in order to make the side surface of the groove portion 16 rough, the groove portion 16 is formed by laser irradiation as described above, and then desmearing is performed.

  Thereafter, the component 12 is supported by the solder layer 18 so as to straddle the groove portion 16 and is electrically connected to the first metal pad 141 via the solder layer 18. Accordingly, the components 12 and 13 can be mounted so that the groove portion 16 exists below, and the component mounting board 1 as shown in FIGS. 1 to 3 can be obtained.

  The present invention has been described in detail with specific examples. However, the present invention is not limited to the above contents, and various modifications and changes can be made without departing from the scope of the present invention.

  For example, in the above specific example, the wiring board 10 includes the core conductor layers M1 and M11, the first conductor layers M2 and M12, and the second conductor layers M3 and M13 on both surfaces of the core board 101. Insulating layer 131 to fourth insulating layer 134 are provided, and on one side of core substrate 101, there are three conductor layers and two insulating layers, but the number of conductor layers and insulating layers is also necessary. Depending on the number, it can be any number.

1 Component mounting board 10 Wiring board,
11 Semiconductor chip 12 Component 15 Wiring pattern 16 Groove

Claims (6)

A wiring board having a pair of terminal pads exposed on the substrate surface;
A component mounted on the pair of terminal pads,
A component mounting substrate filled with resin between the substrate surface and the component,
The substrate surface extends in a crossing direction between the pair of terminal pads and intersecting a first arrangement direction in which the terminal pads constituting the pair of terminal pads are arranged, and from the central portion toward both ends. A groove portion having a narrow width in the first arrangement direction is formed,
The component mounting board, wherein a central portion of the groove is formed at a position corresponding to a center of the component in the intersecting direction.   The component mounting board according to claim 1, wherein side surfaces of the groove portions are configured as continuous surfaces.   The component mounting board according to claim 1, wherein both end portions of the groove portion are formed outward from a projection region of the component.   The component mounting board according to claim 1, wherein an angle formed between a side surface and a bottom surface of the groove is an obtuse angle.   5. The component mounting board according to claim 1, wherein a shape of the groove portion on one end side from the central portion is the same as a shape on the other end side of the central portion.   The component mounting board according to claim 1, wherein a side surface of the groove is a roughened surface.

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