JP2016219737A - Electronic apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent noises caused by semiconductor chip operation.SOLUTION: The electronic apparatus includes: a function module formed by mounting a semiconductor chip on a first wiring substrate; and a second wiring substrate, to which a plurality of the function modules that are parallely arranged is connected, having a layer composed of a thin film capacitor. The thin film capacitor is arranged across the plurality of parallely arranged function modules. The present invention can be applied to a wearable devices or IoT(Internet of Things) devices, for instance.SELECTED DRAWING: Figure 1

Description

  The present disclosure relates to an electronic device, and more particularly to an electronic device in which noise caused by the operation of an IC mounted on an electronic substrate is reduced by a capacitor.

  Conventionally, electronic devices have been equipped with high-speed ICs such as a CPU (Central Processing Unit), MCU (Micro Controller Unit), and memory. As a configuration for suppressing, a method of embedding a capacitor (bypass capacitor) directly under the IC of the substrate on which the IC is mounted has been proposed (for example, see Patent Document 1).

Special table 2010-503199 gazette

By the way, for example, an MCU mounted on a wearable device or an IoT (Internet of Things) device operates at about 10 MHz, and thus a bypass capacitor of about 0.1 μF is required to suppress noise generated due to this. . Specifically, when a parallel plate capacitor having a dielectric constant of 100, a film thickness of 2 μm, and a capacitance of 0.044 μF / cm ² is used as a bypass capacitor, a size of about 15 mm square is required to obtain a capacitance of 0.1 μF. .

  On the other hand, in wearable devices with a small electronic board area, the size of an IC chip such as an MCU is about 2 to 6 mm square, and therefore a bypass capacitor with a small size and a capacity of less than 0.1 μF is directly underneath. Can only be embedded. Therefore, it is difficult to suppress noise in a high frequency band (particularly in the MHz band) caused by an MCU or the like operating at about 10 MHz in an electronic device having a small area of the electronic substrate.

  The present disclosure has been made in view of such a situation, and makes it possible to suppress the influence of noise caused by the operation of a semiconductor chip.

  An electronic apparatus according to a first aspect of the present disclosure includes a functional module in which a semiconductor chip is mounted on a first wiring board and a plurality of the functional modules arranged in parallel. A second wiring board having a layer comprising the thin film capacitor, and the thin film capacitor is disposed across the plurality of functional modules arranged in parallel.

  The first wiring board and the second wiring board may have different core materials.

  The core material of the first wiring board may be glass, and the core material of the second wiring board may be an organic material.

  A through electrode may be formed on the first wiring board.

  A counter electrode sandwiching the thin film capacitor is formed on the second wiring board, and the semiconductor chip on the first wiring board is electrically connected to the counter electrode. Can do.

  One of the counter electrodes of the second wiring board may be a solid electrode and the other may be a divided patterning electrode.

  The functional module may be stacked on the second wiring board.

  The functional module may be connected to each of the opposing surfaces of the second wiring board.

  The functional module may be connected to a recessed portion of the second wiring board.

  A standardized land pattern for connecting the functional module may be formed on the second wiring board.

  The land pattern may include at least a digital power supply terminal, a signal terminal, an analog power supply terminal, and a GND terminal.

  According to one aspect of the present disclosure, it is possible to suppress the influence of noise caused by the operation of the semiconductor chip.

It is sectional drawing which shows the 1st structural example of the electronic board employ | adopted as the electronic device to which this indication is applied. It is sectional drawing which shows the power wiring of the IC chip in a functional module. It is a top view which shows the example of arrangement | positioning of the thin film capacitor with respect to a functional module. It is sectional drawing which shows the 2nd structural example of the electronic substrate employ | adopted as the electronic device to which this indication is applied. It is a figure which shows an example of the formation method of a thin film capacitor. It is sectional drawing which shows the 3rd structural example of the electronic substrate employ | adopted as the electronic device to which this indication is applied. It is sectional drawing which shows the 4th structural example of the electronic substrate employ | adopted as the electronic device to which this indication is applied. It is sectional drawing which shows the 5th structural example of the electronic substrate employ | adopted as the electronic device to which this indication is applied. It is sectional drawing which shows the 6th structural example of the electronic substrate employ | adopted as the electronic device to which this indication is applied. It is sectional drawing which shows the 7th structural example of the electronic substrate employ | adopted as the electronic device to which this indication is applied. It is sectional drawing which shows the 8th structural example of the electronic substrate employ | adopted as the electronic device to which this indication is applied. It is sectional drawing which shows the 9th structural example of the electronic substrate employ | adopted as the electronic device to which this indication is applied. It is sectional drawing which shows the 10th structural example of the electronic substrate employ | adopted as the electronic device to which this indication is applied.

  Hereinafter, the best mode for carrying out the present disclosure (hereinafter referred to as an embodiment) will be described in detail with reference to the drawings.

<First Configuration Example of Electronic Substrate>
FIG. 1 is a cross-sectional view of a first configuration example of an electronic substrate that is employed in an electronic apparatus that is an embodiment of the present disclosure.

  The first configuration example has a structure in which a glass substrate 20 is connected to an organic substrate 10 containing a thin film capacitor 12 as a bypass capacitor, and a semiconductor chip 31 is mounted on the glass substrate 20. Hereinafter, the glass substrate 20 on which the semiconductor chip 31 is mounted is referred to as a functional module 41.

  The organic substrate 10 is provided with a patterning electrode 11 and a solid electrode 13 so as to sandwich the thin film capacitor 12. The organic substrate 10 can be formed by, for example, a coreless built-up method using an organic material on both sides of the thin film capacitor 12.

  The patterning electrode 11 is made of Cu, for example. The solid electrode 13 is made of a metal material having a linear expansion coefficient lower than 15 ppm / K, for example, Ni, in order to reduce the influence of thermal stress when connected to the glass substrate 20 by solder.

The thin film capacitor 12 is a parallel capacitor having a dielectric constant of 100 BaTiO ₃ , a film thickness of 0.9 μm, and a capacitance of 0.1 μF for the purpose of suppressing noise in a high frequency band (particularly in the MHz band) caused by, for example, an MCU operating at about 10 MHz. A plate capacitor can be employed.

  The glass substrate 20 is provided with a solder joint portion 22 having a relatively wide pitch on one surface, and is connected to the organic substrate 10 via the solder joint portion 22. In addition, a solder joint 23 having a relatively narrow pitch is provided on the other surface, and various semiconductor chips 31 are mounted via the solder joint 23. Further, a through electrode (TGV) 21 is formed on the glass substrate 20.

  The function module 41 includes, for example, a main module on which a semiconductor chip having a minimum function (MCU, Bluetooth (registered trademark), etc.), a power supply / battery charge / discharge management function, a power supply module having a wireless power feeding function, These include sensor modules equipped with acceleration sensors, gyros, temperature sensors, humidity sensors, pressure sensors, etc., and communication modules with communication functions such as wireless LAN and 4G LTE. The semiconductor chip 31 mounted on each functional module 41 may be formed as a resin-sealed package or may be a bare chip.

  FIG. 2 is a cross-sectional view showing an example of the power wiring of the semiconductor chip 31 in the functional module 41.

  As shown in the figure, the power supply terminal of the semiconductor chip 31 is connected to the patterning electrode 11 and the solid electrode 13 sandwiching the thin film capacitor 12 of the organic substrate 10 for noise reduction. The patterning electrode 11 may be divided into a digital power patterning electrode 11d and an analog power patterning electrode 11a as shown in the figure.

  FIG. 3 is a top view showing an example of the arrangement of the thin film capacitor 12 with respect to the functional module 41.

  As shown in the figure, since the thin film capacitor 12 extends over a plurality of functional modules 41, the thin film capacitor 12 can be formed to occupy a sufficient area to ensure a required capacity. As shown in FIG. 2, when the patterning electrode 11 is divided into a digital power supply and an analog power supply, the thin film capacitor 12 is also divided into a digital power supply thin film capacitor 12d and an analog power supply thin film capacitor 12a. To form.

  However, when the electronic device is a wearable device or the like and the semiconductor chip 31 mounted on the functional module 41 is an MCU, the MCU does not operate as fast as a CPU mounted on a personal computer or the like. In such a case, the thin film capacitor 12 is not necessarily arranged directly under the IC chip (MCU).

<Second Configuration Example of Electronic Substrate>
FIG. 4 is a cross-sectional view of a second configuration example of the electronic substrate employed in the electronic apparatus according to the embodiment of the present disclosure.

  The second configuration example has a structure in which a plurality of functional modules 41, each of which is resin-sealed, are stacked on the organic substrate 10. By arranging the plurality of functional modules 41 in a stacked manner, the surface area of the electronic substrate can be reduced.

  A rewiring layer 51 is formed between the plurality of resin-sealed functional modules 41 (41c and 41d). In addition, a through resin via 52 is formed in the functional module 41 d connected to the organic substrate 10 including the thin film capacitor 12. A signal line, a GND line, a power supply line, and the like can be arranged in the through resin via 52. These wirings can be shared by a plurality of functional modules 41 to be stacked.

  In the case of FIG. 4, the number of functional modules 41 stacked is 2, but the functional modules 41 may be stacked in more layers.

<Method of forming thin film capacitor>
The thin film capacitor 12 may be formed as shown in FIG. 5 in addition to being embedded in the organic substrate 10 by coreless built-up.

  FIG. 5 shows an example of a method for forming the thin film capacitor 12. A wiring board 61 made of an organic material and a thin film capacitor 12 on which the patterning electrode 11 is formed are separately prepared as shown in FIG. A, and bonded to the wiring board 61 as shown in FIG. The organic substrate 10 may be formed by pressing the thin film capacitor 12 through the layer 62. In this case, the functional module 41 is connected to the thin film capacitor 12 as shown in FIG.

<Third configuration example of electronic substrate>
FIG. 6 is a cross-sectional view of a third configuration example of the electronic substrate employed in the electronic apparatus according to the embodiment of the present disclosure.

  The third configuration example has a structure in which the resin-sealed functional modules 41 are disposed on both surfaces of the organic substrate 10, that is, a structure in which the organic substrate 10 is sandwiched between two functional modules 41. Thereby, the surface area of an electronic substrate can be made small.

  Further, since the thin film capacitor 12 is arranged near the center of the electronic substrate, the stress balance between the front and back of the electronic substrate can be balanced. However, the thin film capacitor 12 may be disposed at an electrically optimal position where the power supply noise is minimized in consideration of the balance between the current amounts on the front and back sides.

<Fourth Configuration Example of Electronic Substrate>
FIG. 7 is a cross-sectional view of a fourth configuration example of the electronic substrate employed in the electronic device according to the embodiment of the present disclosure.

  The fourth configuration example has a structure in which an underfill material 71 is disposed between the organic substrate 10 including the thin film capacitor 12 and the functional module 41 sealed with resin. By providing the underfill material 71, it is possible to increase the rigidity of the entire electronic substrate, and thereby it is possible to prevent the electronic substrate from being deteriorated or damaged due to thermal expansion or contraction caused by a temperature change.

  Furthermore, in order to suppress the deterioration and breakage of the electronic substrate due to the temperature change, it is desirable to make the thermal expansion coefficients of the organic substrate 10 and the glass substrate 20 constituting the functional module 40 close to each other. Specifically, for example, the thermal expansion coefficient of the organic substrate 10 may be adjusted by adding a predetermined filler to the organic substrate 10 or by multilayering the thin film capacitors 12 in the organic substrate 10.

<Fifth Configuration Example of Electronic Substrate>
Next, FIG. 8 shows a cross-sectional view of a fifth configuration example of the electronic substrate employed in the electronic apparatus according to the embodiment of the present disclosure.

  The fifth configuration example has a structure in which the functional module 41 connected to the organic substrate 10 is further sealed with a low thermal conductive material 81 and a high thermal conductive material 82. Specifically, when the electronic device adopting the fifth configuration example is a wearable device, the wearable device is used at a position close to the user's skin, so that the user is not affected by exhaust heat. In addition, a low thermal conductive material 81 is disposed closer to the user's skin, and a higher thermal conductive material 82 having a higher thermal conductivity is disposed farther from the user's skin. Thereby, the strength of the entire electronic substrate can be increased, and the heat generated from the semiconductor chip 31 can be exhausted.

<Sixth Configuration Example of Electronic Substrate>
FIG. 9 is a cross-sectional view of a sixth configuration example of the electronic substrate employed in the electronic apparatus according to the embodiment of the present disclosure.

  The sixth configuration example has a structure in which the concave portion 91 is formed by hollowing out the organic substrate 10, and the functional module 41 is arranged in the concave portion 91. Thereby, the thickness of the electronic substrate can be reduced, and as a result, the height of the electronic device can be reduced.

<Seventh Configuration Example of Electronic Substrate>
FIG. 10 is a cross-sectional view of a seventh configuration example of the electronic substrate employed in the electronic device according to the embodiment of the present disclosure.

  As in the sixth configuration example, the seventh configuration example has a structure in which the organic substrate 10 is hollowed to form the recessed portion 91 and the functional module 41 is arranged in the recessed portion 91.

  Further, in the seventh configuration example, a portion where the bending center when the bending stress is generated on the electronic substrate is the weakest in the electronic substrate (near the thin film capacitor 12, the glass substrate 20, and the solder joint portion 22). ). Thereby, the thickness of the electronic substrate can be reduced, and in addition to the reduction in the height of the electronic device, it is possible to improve the resistance to bending and impact. In addition, if the thickness of the glass substrate 20 is adjusted, the parasitic inductance can be adjusted.

<Eighth configuration example of electronic substrate>
FIG. 11 is a cross-sectional view of an eighth configuration example of the electronic substrate employed in the electronic device according to the embodiment of the present disclosure.

  The eighth configuration example has a structure in which one or more functional module land patterns 100 are arranged on the surface of the organic substrate 10. The functional module land pattern 100 is a group of connection terminals for connecting the functional module 41, and at least a plurality of terminals including a digital power supply terminal 101, a signal terminal 102, an analog power supply terminal 103, and a GND terminal 104 are standardized. It is arranged in.

  By forming the functional module land pattern 100 on the surface of the organic substrate 10, it is possible to realize the organic substrate 10 capable of exhibiting a noise suppression effect regardless of the type of the functional module 41 connected thereto. Moreover, the design man-hour of the air board | substrate 10 can be reduced so that a connection terminal with the functional module 41 may be standardized. Furthermore, although illustration is omitted, if the signal line layout in the organic substrate 10 is also standardized, the number of man-hours can be further reduced.

<Ninth Configuration Example of Electronic Substrate>
FIG. 12 is a cross-sectional view of a ninth configuration example of the electronic substrate employed in the electronic device according to the embodiment of the present disclosure.

  The ninth configuration example has a structure in which two or more thin film capacitors 12 are arranged in the organic substrate 10.

  These two or more layers of thin film capacitors 12 may be electrically connected in parallel via vias 121. In this case, the capacity of the bypass capacitor per area of the organic substrate 10 can be increased. Further, each of these two or more layers of thin film capacitors 12 may be connected to separate power sources.

  The thin film capacitors 12 to be laminated need not all have the same area (capacitance), and the area (capacitance) ratio is, for example, 1, 2, 4, 8,... The capacity may be adjusted.

  Moreover, the rigidity of the organic substrate 10 can be increased by providing two or more layers of the thin film capacitor 12.

<Tenth configuration example of electronic substrate>
FIG. 13 is a cross-sectional view of a tenth configuration example of the electronic substrate employed in the electronic device according to the embodiment of the present disclosure. In the tenth configuration example, the rewiring layer 132 is disposed on the upper surface of the functional module 41 sealed with the resin material 131, and the organic substrate 10 including the thin film capacitor 12 is disposed on the upper surface of the rewiring layer 132. It has a structure. Thereby, the surface area of an electronic substrate can be made small.

  The two organic substrates 10 sandwiching the functional module 41 are connected via the rewiring layer 132 and the through via 133, and the thin film capacitor 12 incorporated in each of them is the same as that in the ninth configuration example described above. Similarly, both can be electrically connected in parallel to increase the capacity of the bypass capacitor, or both can be connected to separate power sources.

<Summary>
According to the first to tenth configuration examples of the electronic substrate described above, it is possible to suppress the influence of noise generated due to the operation of the semiconductor chip 31 on the power supply voltage. In addition, since a thin film capacitor is used as the bypass capacitor, the number of components mounted on the surface layer of the electronic substrate can be reduced, and the mounting area of the electronic substrate can be reduced.

  In addition, the semiconductor chip 31 is not directly mounted on the organic substrate 10 in which the thin film capacitor 12 is incorporated, but is connected to the organic substrate 10 in a state where the semiconductor chip 31 is mounted on the glass substrate 20. A large gap can be reduced. As a result, thermal stress due to a change in temperature in the manufacturing process or in the usage environment can be relieved, and as a result, the reliability of the electronic device can be improved.

  By adopting a structure in which the thin film capacitor 12 is arranged not in the glass substrate 20 but in the organic substrate 10, a glass substrate manufacturing process that requires fine processing and an organic substrate manufacturing process that does not require relatively fine processing are performed. Since it can isolate | separate, a process can be simplified.

  The first to tenth structural examples of the electronic substrate described above can be combined as appropriate.

  The embodiments of the present disclosure are not limited to the above-described embodiments, and various modifications can be made without departing from the scope of the present disclosure.

This indication can also take the following composition.
(1)
A functional module comprising a semiconductor chip mounted on a first wiring board;
A plurality of the functional modules arranged in parallel are connected, and a second wiring board having a layer made of a thin film capacitor;
The thin film capacitor is an electronic device arranged across the plurality of functional modules arranged in parallel.
(2)
The electronic device according to (1), wherein the first wiring board and the second wiring board have different core materials.
(3)
The electronic device according to (2), wherein the core material of the first wiring board is glass, and the core material of the second wiring board is an organic material.
(4)
The through-electrode is formed in the first wiring board. The electronic apparatus according to any one of (1) to (3).
(5)
A counter electrode sandwiching the thin film capacitor is formed on the second wiring board,
The electronic device according to any one of (1) to (4), wherein the semiconductor chip on the first wiring board is electrically connected to the counter electrode.
(6)
One of the counter electrodes of the second wiring board is a solid electrode, and the other is a divided patterning electrode. The electronic apparatus according to (5).
(7)
The electronic device according to any one of (1) to (6), wherein the functional module is stacked on the second wiring board.
(8)
The electronic device according to any one of (1) to (7), wherein the functional module is connected to each of opposing surfaces of the second wiring board.
(9)
The electronic device according to any one of (1) to (8), wherein the functional module is connected to a recessed portion of the second wiring board.
(10)
The electronic device according to any one of (1) to (9), wherein a standardized land pattern for connecting the functional module is formed on the second wiring board.
(11)
The electronic device according to (10), wherein the land pattern includes at least a digital power supply terminal, a signal terminal, an analog power supply terminal, and a GND terminal.

  DESCRIPTION OF SYMBOLS 10 Organic substrate, 11 Patterning electrode, 12 Thin film capacitor, 13 Solid electrode, 20 Glass substrate, 21 Through electrode, 22, 23 Solder joint part, 31 Semiconductor chip, 41 Functional module, 71 Underfill material, 81 Low heat conductive material, 82 High thermal conductivity material, 100 functional module land pattern, 101 digital power terminal, 102 signal terminal, 103 analog power terminal, 104 GND terminal

Claims (11)

A functional module comprising a semiconductor chip mounted on a first wiring board;
A plurality of the functional modules arranged in parallel are connected, and a second wiring board having a layer made of a thin film capacitor;
The thin film capacitor is an electronic device arranged across the plurality of functional modules arranged in parallel. The electronic device according to claim 1, wherein the first wiring board and the second wiring board have different core materials. The electronic device according to claim 2, wherein the core material of the first wiring board is glass, and the core material of the second wiring board is an organic material. The electronic device according to claim 2, wherein a through electrode is formed on the first wiring board. A counter electrode sandwiching the thin film capacitor is formed on the second wiring board,
The electronic device according to claim 2, wherein the semiconductor chip on the first wiring board is electrically connected to the counter electrode. The electronic apparatus according to claim 5, wherein one of the counter electrodes of the second wiring board is a solid electrode and the other is a divided patterning electrode. The electronic device according to claim 2, wherein the functional module is stacked on the second wiring board. The electronic device according to claim 2, wherein the functional module is connected to each of the opposing surfaces of the second wiring board. The electronic device according to claim 2, wherein the functional module is connected to a recessed portion of the second wiring board. The electronic device according to claim 2, wherein a standardized land pattern for connecting the functional module is formed on the second wiring board. The electronic device according to claim 2, wherein the land pattern includes at least a digital power supply terminal, a signal terminal, an analog power supply terminal, and a GND terminal.

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