JP2006066612A - Flip-mounted high-frequency module - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a module which maintains designed performance and secures noise characteristics and is thin as to an IC chip having no constitution for securing GND potential. <P>SOLUTION: The module 100 has an integrated circuit element 112 flip-mounted on a wiring board 101, the module 100 is connected to the wiring board 101 and has a conductive storage container 102 shielding the integrated circuit element 112 from the outside, and the integrated circuit element 112 is connected to the conductive storage container 102 by a conductive member 116. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a module of a high frequency circuit.

A module built in a mobile phone or the like is required to be small, particularly in the thickness direction.
Therefore, conventionally, a technique of flip-mounting an IC chip on a printed circuit board in order to make the module thinner has been implemented (for example, Patent Document 1).

FIG. 4 is a schematic diagram showing an example of a conventional analog high-frequency module using flip mounting.
As shown in FIG. 4, the analog high-frequency module 1 has a printed circuit board 2 to which external connection solder balls 8 are connected. The high frequency IC chip 10 is stored in a space S formed by the printed board 2, the shield case 4 and the solders 6 and 6. The high frequency IC chip 10 is flip-mounted on the printed circuit board 2 by solder 12.
Here, the flip mounting is a method of mounting an integrated circuit element (so-called bare chip) that is not stored in a package. As shown in FIG. 4, solder bumps 12 and 12 are formed on the outer surface of the high frequency IC chip 10 on the printed circuit board 2 side. 12 is formed and soldered onto the printed circuit board 2 for mounting.
Further, a baseband IC chip 14 is flip-mounted on the printed circuit board 2 by solder 16.
Note that a GND (Ground) plate 3 is disposed on the printed circuit board 2 and connected to the solder 6 by a GND securing wire 8.
With such a configuration, the analog high-frequency module is reduced in thickness.
JP-A-11-87549

However, there are a plurality of types of analog high-frequency IC chips. For example, there is an analog high-frequency IC chip that does not have a configuration for securing a GND potential such as a GND potential securing pad on the surface facing the printed circuit board. When such an analog high frequency IC chip is flip-mounted, there is a problem that the GND potential of the analog high frequency IC chip may not be ensured. For this reason, the potential of the back gate terminal of the transistor on the analog high frequency IC chip is different from that at the time of design, and the operation of the entire circuit may be different from the design performance.
In addition, when there is a device with a large parasitic capacitance between the IC chip silicon substrate such as a coil formed on the IC chip, for example, an alternating current flowing through these coils flows into the IC chip silicon substrate. If the GND potential of the analog high-frequency IC chip cannot be secured, there is a problem that the above-described alternating current that has flowed into the IC chip silicon substrate flows into a nearby coil or the like through the parasitic capacitance of this coil, thereby hindering normal circuit operation.

  Accordingly, an object of the present invention is to provide a module having a thinner form while maintaining design performance and ensuring noise characteristics for an IC chip that does not have a configuration for ensuring a GND potential.

  According to the first aspect of the present invention, there is provided a module in which an integrated circuit element is flip-mounted on a wiring board, and has a conductive container that is connected to the wiring board and blocks the integrated circuit element from the outside. The integrated circuit element is achieved by a module that is connected to the conductive container by a conductive member.

According to the configuration of the first invention, in the module, the integrated circuit element is flip-mounted on the wiring board.
Therefore, the module can be configured very thin.
In addition, since the conductive container is connected to the wiring board, if the GND potential of the wiring board is secured, the GND potential of the conductive container connected to the wiring board is also secured. be able to. And since the said integrated circuit element is connected with the said electroconductive container and the said electroconductive member, the GND electric potential of the said integrated circuit element is also ensured. It is easy to secure the GND potential of the wiring board.
Therefore, even when the IC chip itself does not have a configuration for ensuring the GND potential, the above-described configuration can ensure the GND potential, so that the design performance can be maintained.
Furthermore, external noise can be blocked by the conductive container.
Thereby, it is possible to provide a module with a thinner configuration while maintaining design performance and ensuring noise characteristics for an IC chip that does not have a configuration for securing the GND potential.

  According to a second invention, in the configuration of the first invention, the integrated circuit element has a conductive layer portion on the conductive member side, and the conductive layer portion includes the conductive container and the conductive member. It is connected by.

  According to the configuration of the second invention, the integrated circuit element has the conductive layer portion, and the conductive layer portion is connected to the conductive container and the conductive member. The GND potential of the circuit element can be effectively ensured.

  According to a third invention, in the configuration of the second invention, the conductive member is in contact with the entire surface of the conductive layer portion.

  According to the structure of 3rd invention, since the said electroconductive member is contacting the whole surface of the said electroconductive layer part, it can prevent that a part of said electroconductive layer part does not become a GND electric potential. .

  According to a fourth invention, in any one of the first to third inventions, the conductive member is a soft member.

  According to the structure of 4th invention, since the said electroconductive member is a soft member, when the stress is received from the said electroconductive storage container, the stress can be absorbed. For this reason, it is possible to prevent the stress from the conductive container from reaching the integrated circuit element.

  According to a fifth invention, in any one of the first to fourth inventions, the integrated circuit element is an analog high-frequency integrated circuit element.

  According to the configuration of the fifth invention, since the integrated circuit element is an analog high-frequency integrated circuit element, the design performance is maintained for the analog high-frequency integrated circuit element that is not designed for flip mounting, and Therefore, it is possible to provide a module having a thinner form while ensuring noise characteristics.

  A sixth invention is the structure of the first to fifth inventions, wherein the conductive member is any one of a conductive paste, a conductive rubber, a conductive spring, a conductive sponge, a conductive adhesive, or a metal plate. 6. The module according to claim 1, wherein the module is any one of the above.

  According to the configuration of the sixth invention, the conductive member is one of a conductive paste, a conductive rubber, a conductive spring, a conductive sponge, a conductive adhesive, or a metal plate. Therefore, the electrical and physical connection between the integrated circuit element and the conductive container can be ensured, and the stress from the conductive container can be reliably prevented from reaching the integrated circuit element. .

  A seventh invention is characterized in that in any one of the first to sixth inventions, a conductive securing member is provided in contact with the entire surface of the conductive layer portion.

  According to the structure of 7th invention, since it has the electroconductive ensuring member which contact | connects the whole surface of the said electroconductive layer part, the GND potential of the said integrated circuit element can be ensured reliably.

  According to an eighth invention, in any one of the first to seventh inventions, the parasitic inductance of the conductive member is within an allowable range for normal operation of the integrated circuit element. And

  According to the configuration of the eighth invention, since the parasitic inductance of the conductive member is within an allowable range for normal operation of the integrated circuit element, normal operation of the integrated circuit element is controlled by the parasitic inductance. Inhibition can be prevented.

Preferred embodiments of the present invention will be described below in detail with reference to the accompanying drawings.
The embodiments described below are preferred specific examples of the present invention, and thus various technically preferable limitations are given. However, the scope of the present invention is particularly limited in the following description. Unless otherwise stated, the present invention is not limited to these embodiments.

(First embodiment)
FIG. 1 is a schematic diagram showing an analog high-frequency module 100 according to the first embodiment of the present invention. This analog high frequency module 100 is an example of a module.

As shown in FIG. 1, the analog high-frequency module 100 includes a printed circuit board 101 that is a wiring board, for example. The printed circuit board 101 has a GND potential secured by a GND potential securing means (not shown).
On the outer surface 101b of the printed circuit board 101, external connection solder balls 106 and 106 for connection to the outside and a baseband IC chip 108 are arranged. The baseband IC chip 108 is flip-mounted on the printed circuit board 101 with solders 110 and 110.

  Further, on the outer surface 101a of the printed board 101, for example, a high frequency IC chip 112, which is an integrated circuit element, is flip-mounted. The high frequency IC chip 112 is an analog high frequency IC chip and is an example of an analog high frequency integrated circuit element.

That is, the high-frequency IC chip 112 is a so-called bare chip that is not stored in a package, and solder bumps 114 and 114 are formed on the outer surface 112b of the high-frequency IC chip 112 on the printed circuit board 101 side, and soldered onto the printed circuit board 101. Has been implemented. As described above, the baseband IC chip 108 is also flip-mounted on the printed circuit board 101. Thus, since the baseband IC chip 108 and the high frequency IC chip 112 are flip-mounted on the printed circuit board 101, the module can be made very thin.
Since the baseband IC chip 108 is flip-mounted on the outer surface 101b of the printed circuit board 101 and the high-frequency IC chip 112 is flip-mounted on the outer surface 101a of the printed circuit board 101, the configuration of the analog high-frequency module 1 shown in FIG. The planar dimensions can also be reduced.

As shown in FIG. 1, the analog high frequency module 100 includes a shield case 102 that is a conductive container. The shield case 102 is made of metal and connected to the printed circuit board 101 by solders 104 and 104. As described above, since the printed circuit board 101 has a GND potential, the shield case 102 electrically and physically connected to the printed circuit board 101 also has the GND potential.
As shown in FIG. 1, the printed circuit board 101 and the shield case 102 form a space T, and the high frequency IC chip 112 is stored in the space T, whereby the high frequency IC chip 112 is blocked from the outside. As a result, noise due to electromagnetic waves from outside the analog high-frequency module 100 can be prevented from affecting the high-frequency IC chip 112.

As shown in FIG. 1, the high frequency IC chip 112 is connected to the shield case 102 by a conductive paste 116 which is a conductive member. That is, the high frequency IC chip 112 is electrically and physically connected to the shield case 102 by the conductive paste 116. As described above, since the GND potential is secured in the shield case 102, the GND potential of the high frequency IC chip 112 is also secured.
Therefore, even if the high frequency IC chip 112 itself does not have a configuration for securing the GND potential, the above-described configuration can secure the GND potential of the high frequency IC chip 112. Therefore, the design performance of the high frequency IC chip 112 can be ensured. Can be maintained.
In addition, since the conductive paste 116 is a soft member, when stress is received from the shield case 102, the stress can be absorbed. For this reason, it is possible to prevent the stress from the shield case 102 from reaching the high frequency IC chip 112 in advance.

As shown in FIG. 1, the high frequency IC chip 112 has, for example, a metal coating layer 112c which is a conductive portion on the conductive paste 116 side. The metal coating layer 112c is generated by adding a metal such as Au in the manufacturing process of the high frequency IC chip 112, for example, at the wafer manufacturing stage.
As shown in FIG. 1, the outer surface 112 a of the metal coating layer 112 c is connected to the shield case 102 with a conductive paste 116.
For this reason, the GND potential of the high frequency IC chip 112 can be effectively secured.

  As shown in FIG. 1, the conductive paste 116 is in contact with the entire surface of the metal coating layer 112. For this reason, it can prevent that a part of metal coating layer 112 does not become a GND potential.

  With the above configuration, it is possible to provide a thinner module that maintains design performance and noise characteristics for an IC chip that does not have a configuration for securing the GND potential.

Unlike the present embodiment, the high frequency IC chip 112 and the shield case 102 may be connected by a conductive rubber, a conductive spring, a conductive sponge, or a conductive adhesive.

(Modification of the first embodiment)
FIG. 2 is a schematic diagram showing the analog high-frequency module 200.
As shown in FIG. 2, the conductive paste 116 </ b> A of the analog high-frequency module 200 is in contact with the entire upper surface 102 a on the space T side of the shield case 102.
For this reason, the GND potential of the high frequency IC chip 112 can be more effectively ensured.

(Second Embodiment)
Next, a second embodiment will be described.
Since the configuration of the analog high-frequency module 300 in the second embodiment has many configurations in common with the analog high-frequency module 100 of the first embodiment, common portions are denoted by the same reference numerals, and the description thereof is omitted. Hereinafter, the main differences will be mainly described.

FIG. 3 is a schematic diagram showing the analog high-frequency module 300 and the like.
As shown in FIG. 3A, the analog high-frequency module 300 includes, for example, a metal plate 118 that is a conductive ensuring member that contacts the entire outer surface 112a of the metal coating layer 112c of the high-frequency IC chip 112.
The metal plate 118 and the shield case 102 are electrically and physically connected by a metal spring 120.

  As described above, since the high frequency IC chip 112 is connected not only to the metal spring 120 but also to the shield case 102 via the metal plate 118, the GND potential of the high frequency IC chip 112 can be reliably ensured.

The metal spring 120 is configured such that its parasitic inductance is within an allowable range for normal operation of the high-frequency IC chip 112. For example, as shown in FIG. 3B, the width W1 of the metal spring 120 is larger than, for example, the width W2 so that the parasitic inductance of the metal spring 120 is within the allowable range of normal operation of the high-frequency IC chip 112. .
For this reason, it is possible to prevent the normal operation of the high frequency IC chip 112 from being hindered by the parasitic inductance.

  The present invention is not limited to the embodiments described above. Furthermore, the above-described embodiments may be combined with each other.

It is the schematic which shows the analog high frequency module of 1st Embodiment. It is the schematic which shows an analog high frequency module. It is the schematic which shows the analog high frequency module of 2nd Embodiment. It is the schematic which shows an example of the conventional analog high frequency module.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 100,200,300 ... Analog high frequency module, 101 ... Printed circuit board, 102 ... Shield case, 104, 110 ... Solder, 106 ... Solder ball for external connection, 108 ... Baseband IC chip, 112... High frequency IC chip, 116, 116 A, conductive paste, 118, metal plate, 120, metal spring

Claims (8)

A module in which an integrated circuit element is flip-mounted on a wiring board,
A conductive container connected to the wiring board and blocking the integrated circuit element from the outside;
The module, wherein the integrated circuit element is connected to the conductive container by a conductive member. The integrated circuit element has a conductive layer portion on the conductive member side,
The module according to claim 1, wherein the conductive layer portion is connected to the conductive container by the conductive member.   The module according to claim 2, wherein the conductive member is in contact with the entire surface of the conductive layer portion.   The module according to claim 1, wherein the conductive member is a soft member.   The module according to any one of claims 1 to 4, wherein the integrated circuit element is an analog high-frequency integrated circuit element.   6. The conductive member according to claim 1, wherein the conductive member is any one of a conductive paste, a conductive rubber, a conductive spring, a conductive sponge, a conductive adhesive, or a metal plate. The listed module.   The module according to any one of claims 1 to 6, further comprising a conductive securing member in contact with the entire surface of the conductive layer portion.   8. The module according to claim 1, wherein a parasitic inductance of the conductive member is within an allowable range for normal operation of the integrated circuit element.

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