JP2010129877A - Electronic component module - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electronic component module capable of sufficiently dissipating heat of a substrate. <P>SOLUTION: The module 1 includes a substrate 2 having an IC 11 and electrode pads 5 and 5, and an inductor L having terminals 8 and 8 electrically connected to the electrode pads 5 and a body L13, and disposed over the side of a top surface 2a of the substrate 2. Further, the module 1 has a heat dissipation pattern 14 brought into contact with the top surface 2a of the substrate 2 and a reverse surface 13b of the body 13 between the substrate 2 and inductor L. The heat of the substrate 2 is therefore positively conducted to the inductor L with high heat conductivity by the heat dissipation pattern 14 and is dissipated by the inductor L. Here, both ends 14a of the heat dissipation pattern 14 project from the inductor L when viewed along a normal to the top surface 2a, so the heat conduction path by the heat dissipation pattern 14 to the inductor L is expanded to make the heat conduction suitable. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an electronic component module, and more particularly, to an electronic component module arranged so that passive components are stacked on one main surface side of a substrate.

2. Description of the Related Art Conventionally, electronic component modules used in, for example, cellular phones and the like do not know where high integration remains, and further downsizing is required. Therefore, as a recent electronic component module, it comprises a substrate having a circuit and a plurality of electrode pads, and a passive component having a plurality of terminals and a body electrically connected to the electrode pads, the passive component being a substrate The thing arrange | positioned so that it may overlap with the one main surface side is developed (for example, refer patent document 1).
Japanese Patent Laid-Open No. 2004-63676

  Here, the electronic component module is generally mounted on a mother board, and heat generated on the board is transmitted through the mother board by using a wiring path between the circuit of the board and the mother board as a heat propagation path. Dissipate heat. However, in such an electronic component module, there is a possibility that the heat of the substrate may not be sufficiently dissipated in some cases.

  Then, this invention makes it a subject to provide the electronic component module which can fully radiate the heat | fever of a board | substrate.

  In order to solve the above problems, an electronic component module according to the present invention includes a substrate having a circuit and a plurality of electrode pads, a plurality of terminals electrically connected to the electrode pads, and a main body. A passive component disposed so as to be superimposed on the main surface side, and having a heat dissipation portion that is in contact with one main surface of the substrate and the surface of the main body on the substrate side between the substrate and the passive component, Is characterized in that at least a part thereof protrudes from the passive component when viewed from the direction along the normal line of one principal surface.

  In this electronic component module, the heat of the substrate is actively propagated to the passive component having a relatively high thermal conductivity by the heat radiating section, and is radiated by the passive component. Here, since the heat dissipating part protrudes from the passive component in the direction along the normal line of one main surface, the heat propagation path to the passive component by the heat dissipating part is expanded, and thus such heat propagation is suitable. Therefore, according to the present invention, it is possible to sufficiently dissipate the heat of the substrate.

  Here, the circuit is preferably provided inside the substrate. As described above, when the circuit as the heat generation source is provided inside, the heat of the substrate is hardly dissipated, and thus the above effect, that is, the effect of sufficiently dissipating the heat of the substrate becomes remarkable.

  Moreover, it is preferable that the heat conductivity of a thermal radiation part is higher than the heat conductivity of a board | substrate. In this case, the heat of the substrate can be more actively propagated to the passive component by the heat radiating portion.

  Further, the electrode pad is preferably provided on one main surface side of the substrate, the terminal is provided so as to be convex on the substrate side, and the thickness of the heat radiating portion is preferably thicker than the thickness of the electrode pad. In this case, the heat dissipating part thicker than the electrode pad is engaged between the pair of convex terminals (valley shape), and functions as a pedestal that regulates the displacement of the passive component. Therefore, it is possible to mount passive components with high accuracy.

  The substrate is preferably an IC-embedded substrate in which an IC is incorporated as a circuit, and the passive component preferably functions as an inductor. In this case, the electronic component module can be used as an integrated power source. Thus, by using an integrated power supply using a substrate with a built-in IC, the wiring connecting the passive component and the IC can be shortened, and the efficiency of the power supply can be improved.

  Moreover, it is preferable that the heat radiating part is connected to the ground of the circuit. In this case, heat propagating through the wiring path connected to the circuit on the board can be propagated to the passive component via the ground and the heat radiating portion and radiated to the surroundings.

  According to the present invention, it is possible to sufficiently dissipate the heat of the substrate.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the following description, the same or equivalent elements will be denoted by the same reference numerals, and redundant description will be omitted.

  FIG. 1 is a sectional view showing a DC-DC converter module according to the first embodiment of the present invention, and FIG. 2 is a top view showing the DC-DC converter module of FIG. As shown in FIG. 1, a DC-DC converter module (electronic component module) 1 according to this embodiment is a small integrated power supply module incorporated in a mobile device such as a mobile phone.

  The DC-DC converter module 1 is arranged so as to be superimposed on an IC-embedded substrate (substrate) 2 in which an IC (circuit) 11 is embedded, and on the surface (one main surface) 2a side of the IC-embedded substrate 2. And an inductor (passive component) L electrically connected to the substrate 2, and these are joined on the mother board 12. Note that a capacitor (not shown) is installed on the mother board 12, whereby the DC-DC converter module 1 operates as a DC-DC converter.

  FIG. 3 is a circuit diagram of the DC-DC converter module of FIG. As shown in FIG. 3, the DC-DC converter module 1 constitutes a circuit 10 which is a general chopper type DC-DC converter circuit. The IC 11 includes a control circuit CU and switching elements S1 and S2 therein. The control circuit CU performs a predetermined step-up / step-down operation by driving the switching elements S1 and S2 with respect to the input DC voltage input from the voltage input terminal Vin. The control circuit CU is provided with an enable terminal EN. The inductor L constitutes a smoothing circuit with the capacitor C2, and outputs a smooth output DC voltage from the voltage output terminal Vout.

  As shown in FIGS. 1 and 2, the IC-embedded substrate 2 has a substantially flat plate shape, and has a resin layer (resin in the substrate) 7 containing the IC 11 inside, and this resin layer 7 is on the surface 2 a side. It is configured to be sandwiched between the upper layer 3 and the lower layer 4 on the back surface 2b side. The built-in substrate 2 has a pair of electrode pads 5 and 5 provided on the front surface 2a side, and solder balls 6 provided on the back surface 2b.

  The electrode pads 5 and 5 are made of copper, for example, and extend along the Y direction at both ends in the X direction of the surface 2a. The solder ball 6 is for electrically and mechanically joining the DC-DC converter module 1 to the mother board 12. The solder balls 6 correspond to, for example, the voltage input terminal Vin, the current output terminal Lout, the enable terminal EN, and the ground terminal GND shown in FIG.

  Returning to FIG. 1, through holes 21, 22, and 23 are provided in each of the upper layer 3, the resin layer 7, and the lower layer 4. The IC 11, the electrode pad 5, and the solder ball 6 are electrically connected to each other through a conductive material 25 such as copper in the through holes 21, 22, and 23 and a bump 24 formed on the electrode pad of the IC 11. Has been.

  The inductor L is a so-called chip inductor having a substantially flat plate shape, and has a main body 13 and a pair of terminals 8 and 8. The outer wall of the main body 13 is made of a magnetic material, and here, it is made of ferrite. The terminals 8 and 8 are provided at both ends of the main body 13 in the X direction, and are configured to be convex outward with respect to the front surface 13a and the back surface 13b of the main body 13, respectively. That is, the terminals 8 and 8 are convex toward the IC-embedded substrate 2 side with respect to the back surface 13b on the IC-embedded substrate 2 side in the main body 13. Further, the terminals 8 and 8 are electrically connected to the electrode pads 5 and 5 via the solder fillets 9, thereby realizing an electrical connection between the IC built-in substrate 2 and the inductor L.

  Here, the DC-DC converter module 1 of the present embodiment includes a heat radiation pattern 14 provided so as to be interposed between the IC built-in substrate 2 and the inductor L. The heat dissipation pattern 14 is to propagate the heat to the inductor L so that heat generated in the IC-embedded substrate 2 (particularly, the IC 11) is radiated to the outside through the inductor L. The heat radiation pattern 14 is in contact (contact) with both the front surface 2 a of the IC-embedded substrate 2 and the back surface 13 b of the main body 13. In other words, the heat dissipation pattern 14 is in thermal and mechanical contact with the front surface 2a and the back surface 13b.

  The heat radiation pattern 14 has a thermal conductivity higher than that of the IC-embedded substrate 2. Here, the heat dissipation pattern 14 is formed of a metal such as copper, for example, and the thermal conductivity thereof is higher than the thermal conductivity of the resin layer 7 of the IC-embedded substrate 2. In addition, the thickness H1 of the heat dissipation pattern 14 is greater than the thickness H2 of the electrode pad 5, and the width of the heat dissipation pattern 14 in the X direction is substantially equal to the width of the IC 11 in the X direction. Furthermore, the heat radiation pattern 14 is connected to the ground terminals (ground) G1 and G2 (see FIG. 3) of the IC 11 so that heat can be propagated between the wiring paths of the IC 11.

  As shown in FIG. 2, the heat dissipation pattern 14 here is provided between the electrode pads 5 and 5 and has a pad shape (sheet shape) extending in the Y direction as with the electrode pad 5. It is formed in a partial region of the underfill material layer 28b. Further, both end portions 14a in the extending direction of the heat radiation pattern 14 are exposed to the outside. That is, at least a part of the heat radiation pattern 14 protrudes from the inductor L when viewed from the direction (Z direction) along the normal line of the surface 2a. In other words, a part of the region of the heat radiation pattern 14 protrudes from the projection region when the inductor L is projected onto the IC built-in substrate 2.

  Further, as shown in FIG. 1, a through hole 26 is provided in the upper layer 3 of the resin layer (resin in the substrate) 7 including the IC 11 in order to bring the heat radiation pattern 14 into thermal proximity to the IC 11. The heat radiation pattern 14 and the conductive pattern 27 on the IC 11 side of the upper layer 3 are connected to each other through the inner conductive material 25. Such a structure makes it possible to obtain a higher heat dissipation effect.

  In the DC-DC converter module 1, an underfill material layer 28a made of, for example, an epoxy resin having insulating properties and heat resistance is provided so as to cover the front surface 2a and the back surface 2b of the IC-embedded substrate 2. At the same time, an underfill material layer 28b similar to the underfill material layer 28a is provided between the IC built-in substrate 2 and the inductor L so as to fill a region other than the heat radiation pattern 14. The resin used for the underfill material layers 28a and 28b is not limited as long as the resin has insulating properties and heat resistance.

  In the DC-DC converter module 1 configured as described above, the heat generated on the back surface 2 b side in the IC 11 of the IC-embedded substrate 2 is transmitted through the wiring path of the IC 11 and propagates to the motherboard 12 through the solder balls 6. Then, heat is radiated from the mother board 12 to the outside (heat propagation path A).

  In addition, in the present embodiment, as described above, the heat radiation pattern 14 is provided so as to be interposed between the IC-embedded substrate 2 and the inductor L. Therefore, in the heat generated on the surface 2a side in the IC 11, Then, it propagates to the inductor L through the heat radiation pattern 14 and is radiated from the inductor L to the outside (heat propagation path B). At the same time, since both end portions 14a of the heat radiation pattern 14 protrude from the inductor L and are exposed, the heat generated on the surface 2a side in the IC 11 is radiated from both end portions 14a to the outside (the heat of FIG. 2). Propagation path C).

  Further, as described above, since the heat radiation pattern 14 is connected to the ground terminals G1 and G2 of the IC 11, heat generated on the back surface 2b side in the IC 11 is radiated from the heat propagation path A through the ground terminals G1 and G2. It is transmitted to the pattern 14 and then propagates to the inductor L and is also radiated from the inductor L to the outside.

  As described above, according to the present embodiment, the heat generated in the IC-embedded substrate 2 is not only radiated from the mother board 12 to the outside, but also radiated to the main body 13 of the inductor L made of a magnetic material having high thermal conductivity. It is actively propagated by the pattern 14. Thereby, the heat of the built-in substrate 2 can be radiated by the inductor L. That is, the inductor L can function as a heat sink.

  At this time, since both end portions 14a of the heat radiation pattern 14 protrude from the inductor L when viewed in the Z direction, the heat radiation pattern 14 also has a heat radiation effect on the surroundings, and the heat propagation path B substantially expands. Propagation is preferred. In addition, it is possible to diffuse (separate) heat that tends to stay between the IC-embedded substrate 2 and the inductor L, and to dissipate heat from both ends 14a as described above. Therefore, according to this embodiment, the heat of the IC built-in substrate 2 can be sufficiently dissipated.

  In the present embodiment, since the IC 11 is built in as described above, the IC 11 can be arranged so as to overlap the inductor L and the inductor L, and the size can be reduced. Here, in the case of the IC built-in substrate 2, since the IC 11 as a heat generation source is built in, there is a concern that heat is trapped inside and it is difficult to dissipate heat. In this respect, in the present embodiment, since the heat of the IC-embedded substrate 2 can be sufficiently dissipated as described above, the present embodiment is particularly effective for the IC-embedded substrate 2 and realizes high heat dissipation while reducing the size. It can be said that this is a DC-DC converter module.

  In the present embodiment, as described above, the thermal conductivity of the heat dissipation pattern 14 is set higher than the thermal conductivity of the IC-embedded substrate 2. Therefore, the heat of the IC 11 is positively propagated to the heat radiation pattern 14 and is more actively propagated to the inductor L.

  In the present embodiment, as described above, the electrode pad 5 is provided on the surface 2a side of the IC-embedded substrate 2, and the terminals 8 and 8 are provided in a convex shape on the IC-embedded substrate 2 side. The thickness of the heat dissipation pattern 14 is thicker than the thickness of the electrode pad 5. Therefore, the heat radiation pattern 14 is engaged with the pair of terminals 8 and 8 (valley shape), and the heat radiation pattern 14 functions as a pedestal that regulates the deviation of the inductor L. Therefore, for example, in the reflow process, the inductor L can be placed on the IC-embedded substrate 2 with high accuracy, and the inductor L can be mounted with high accuracy.

  In addition, when the thickness of the heat radiation pattern 14 is larger than the thickness of the electrode pad 5 in this way, the solder fillet 9 can easily enter between the terminal 8 and the electrode pad 5. The spread of the fillet 9 in the X direction can be suppressed.

  In the present embodiment, as described above, since the heat radiation pattern 14 is connected to the ground terminals G1 and G2 of the IC 11, the heat of the IC 11 propagating through the heat propagation path A is transmitted via the ground terminals G1 and G2. It is possible to propagate to the inductor L and dissipate heat with the inductor L. Since the IC 11 normally generates heat particularly on the back surface 2b side, the above effect of dissipating the heat propagating through the heat propagation path A with the inductor L is particularly effective.

  In the present embodiment, as described above, the heat dissipation pattern 14 and the conductive pattern 27 of the upper layer 3 are connected to each other via the conductive material 25 in the through hole 26. Thereby, the heat radiation pattern 14 can be brought into thermal proximity to the IC 11 to the manufacturing limit, and the heat of the IC 11 can be more actively propagated to the heat radiation pattern 14.

  By the way, in general, the inductor L in the conventional DC-DC converter module is mounted on the IC-embedded substrate 2 with its terminals 8 and electrode pads 5 connected by solder fillets 9. On the other hand, since the inductor L of this embodiment is connected to the IC-embedded substrate 2 not only by the solder fillet 9 but also by the heat radiation pattern 14, it can exhibit excellent impact resistance as compared with the conventional module.

  In the present embodiment, the heat radiation pattern 14 is formed of a metal such as copper, but may be formed of a metal such as gold or silver, a resin in which metal particles or carbon particles are dispersed, or a polymer sheet. It may be formed of other materials having high thermal conductivity such as a graphite sheet prepared by thermally decomposing at a high temperature. When high heat dissipation is required, a metal is preferable, and when high adhesion is prioritized, a resin in which metal particles or carbon particles are dispersed is preferable, and can be appropriately selected depending on the situation.

  The metal particles and carbon particles may be any of spherical particles, plate-like particles, needle-like particles, etc., and the shape is not particularly limited, but if it is plate-like particles or needle-like particles, for the following reason It is preferable in terms of heat dissipation. That is, when the metal particles or carbon particles are plate-like particles or needle-like particles, the heat radiation pattern 14 is arranged in a direction parallel to the IC-embedded substrate 2. This is because heat is more easily diffused in a direction parallel to the.

  Further, if the heat radiation pattern 14 is a sheet having thermal diffusion anisotropy in the extending direction, it is further advantageous in terms of heat radiation. Moreover, the formation method of said heat radiating pattern 14 may apply | coat not only the vacuum film-forming methods, such as sputtering, but may apply | coat and dry the coating liquid which made the metal the paste form by methods, such as screen printing.

  Next, a second embodiment of the present invention will be described. FIG. 4 is a sectional view showing a DC-DC converter module according to a second embodiment of the present invention. As shown in FIG. 4, the DC-DC converter module 50 of the present embodiment is different from the first embodiment in that the heat radiation pattern 14 is in contact with the main body 13 of the inductor L through the resin 51. is there.

  The resin 51 enhances the insulation between the inductor L and the heat dissipation pattern 14 and is provided between the main body 13 of the inductor L and the heat dissipation pattern 14 so as to be in contact with them. The resin 51 here is in the form of grease, and for example, a heat-dissipating silicon material having a high thermal conductivity is used.

  Also in this embodiment, the same effect as the above embodiment, that is, the heat of the IC built-in substrate 2 is positively propagated to the inductor L by the heat radiation pattern 14 and the resin 51 to sufficiently dissipate the heat of the IC built-in substrate 2. There is an effect that can be done.

  In the present embodiment, as described above, since the heat radiation pattern 14 is in contact with the main body 13 of the inductor L through the resin 51, it is possible to improve the insulation between the inductor L and the heat radiation pattern 14. . In the present embodiment, the heat dissipation pattern 14 and the resin 51 constitute a heat dissipation portion.

  The preferred embodiment of the present invention has been described above, but the present invention is not limited to the above embodiment. For example, in the above embodiment, a pair of electrode pads 5 and terminals 8 are provided, but three electrode pads 5 and so-called three-terminal types may be provided, and a plurality of electrode pads 5 and terminals 8 may be provided.

  Moreover, in the said embodiment, although the width | variety of the X direction of the thermal radiation pattern 14 was made substantially equal to the width | variety of the X direction of IC11, it is not limited to this. For example, if insulation with the electrode pad 5 can be secured, the width of the heat radiation pattern 14 in the X direction is larger than the width of the IC 11 in the X direction as shown in FIG. A heat radiation pattern 14 having such a width may be provided. In this case, the heat of the IC-embedded substrate 2 can be suitably transmitted to the inductor L, and the function as a pedestal of the heat radiation pattern 14 is suitably exhibited.

  Further, as shown in FIG. 5B, the width of the heat radiation pattern 14 in the X direction may be smaller than the width of the IC 11 in the X direction. In short, the surface between the IC built-in substrate 2 and the inductor L is important. What is necessary is just to contact (thermally contact) 2a and the back surface 13b.

  The connection between the heat dissipation pattern 14 and the ground terminals G1 and G2 and the connection between the heat dissipation pattern 14 and the conductive pattern 27 in the above embodiment are electrical and mechanical. In a broad sense, any thermal connection is acceptable.

  Incidentally, although the inductor L has been described as an example of the passive component in the above embodiment, examples of the passive component include a filter in which an inductor and a capacitor are combined, a SAW device (filter), a capacitor, a resistor, a capacitor with a built-in resistor, Various elements such as a varistor, a thermistor, an antenna, an isolator, and a circulator may be applied. Furthermore, the present invention can be applied to devices other than the DC-DC converter module.

It is sectional drawing which shows the module for DC-DC converters concerning 1st Embodiment of this invention. It is a top view of the module for DC-DC converters of FIG. It is a circuit diagram in the module for DC-DC converters of FIG. It is sectional drawing which shows the module for DC-DC converters concerning 2nd Embodiment of this invention. It is sectional drawing which shows the module for DC-DC converters which concern on the other example of this invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1,50 ... DC-DC converter module (electronic component module), 2 ... IC built-in substrate (substrate), 2a ... Surface (one main surface), 5 ... Electrode pad, 7 ... Resin layer (resin in substrate), DESCRIPTION OF SYMBOLS 8 ... Terminal, 11 ... IC (circuit), 13 ... Main body, 13b ... Back surface (substrate side surface), 14 ... Heat radiation pattern (heat radiation part), G1, G2 ... Ground terminal (ground), H1 ... Thickness of heat radiation pattern H2: electrode pad thickness, L: inductor (passive component).

Claims (6)

A substrate having a circuit and a plurality of electrode pads;
A plurality of terminals electrically connected to the electrode pad and a main body, and a passive component disposed so as to be superimposed on one main surface side of the substrate, and
Between the substrate and the passive component, a heat dissipation portion that is in contact with the one main surface of the substrate and the surface of the main body on the substrate side,
The electronic component module, wherein at least a part of the heat radiating part protrudes from the passive component when viewed from a direction along a normal line of the one main surface.   The electronic component module according to claim 1, wherein the circuit is provided inside the substrate.   The electronic component module according to claim 1, wherein the thermal conductivity of the heat radiating unit is higher than the thermal conductivity of the substrate. The electrode pad is provided on one main surface side of the substrate,
The terminal is provided to be convex on the substrate side,
The electronic component module according to claim 1, wherein a thickness of the heat radiating portion is thicker than a thickness of the electrode pad. The substrate is an IC-embedded substrate in which an IC is incorporated as the circuit,
The electronic component module according to claim 1, wherein the passive component functions as an inductor. The electronic component module according to claim 1, wherein the heat dissipation unit is connected to a ground of the circuit.

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