JP2010129967A - Electronic circuit module - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electronic circuit module that allows repair work for removing the electronic circuit module from a mother board after mounting it, to be easily and rapidly carried out, and does not induce undesired thermal destruction. <P>SOLUTION: This electronic circuit module 1 is provided with: an insulation board 2 with a group of electrodes 5 for external connection arranged on its bottom face 2a; circuit elements 3 mounted on the insulation board 2; and a shield cover 4 mounted on the insulation board 2 and covering the circuit elements 3, and the module is mounted by solder-connecting the group of the electrodes 5 to a mother board 20. A mesh-like conductive pattern 7 comprising a plurality of annular conductive parts 7a individually surrounding the group of the electrodes 5, and a plurality of connection conductive parts 7b each connecting the adjacent annular conductive parts 7a to each other and extending in a lattice-like form, is formed on the bottom face 2a of the insulation board 2. On side faces 2b of the insulation board 2, heating terminal parts 8 extending from the mesh-like conductive pattern 7 are arranged. Solder bumps 10 are attached to the electrodes 5, respectively, and only grounding electrodes 5a out of the group of the electrodes 5 are connected to the mesh-like conductive pattern 7. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an electronic circuit module in which an insulating substrate on which a circuit element is mounted has an electrode group for external connection, and the electrode group is mounted by soldering to a mother board. In particular, the solder is remelted after mounting. It is related with the electronic circuit module considered so that it can remove from a motherboard by doing.

  Electronic circuit modules mounted on a motherboard are widely known to have a configuration in which circuit elements are mounted on one surface of an insulating substrate and covered with a shield cover, and an external connection electrode group is disposed on the other surface of the insulating substrate. (For example, refer to Patent Document 1). In this type of electronic circuit module, the circuit elements on the insulating substrate are electrically connected to an external connection electrode group through a through hole or the like. In addition, there is a configuration in which the ground function is enhanced by widely covering one surface or the other surface of the insulating substrate with a ground conductor layer within a possible range.

In addition, when the electrode group of the electronic circuit module is disposed in an inner region than the peripheral edge of the bottom surface of the insulating substrate, a solder bump (solder ball) is often attached to the electrode group. By doing so, a large number of electrode groups that cannot be seen from the outside when mounted can be soldered to the motherboard with high precision.
JP 11-26623 A

  By the way, when a motherboard on which an electronic circuit module is mounted is incorporated as a main board of a small electronic device or the like, a high-definition wiring pattern is formed on the motherboard to realize a multifunctional and complicated circuit configuration. In many cases, various electronic components are mounted. For this reason, if a failure is detected in the performance of the electronic circuit module and its mounting state after mounting on the motherboard, discarding the entire motherboard as a defective product results in a large loss in terms of cost and extremely poor production efficiency. Therefore, in such a case, a repair operation may be performed in which only the electronic circuit module in which a failure is detected is removed from the motherboard and replaced.

  When performing such repair work, it is necessary to heat and remelt the solder connecting the electrode group for external connection of the electronic circuit module to the corresponding electrode group on the motherboard side. Air was blown onto the electronic circuit module to melt the solder interposed between the insulating substrate and the motherboard, and then the electronic circuit module was removed from the motherboard.

  However, since the electrode group for external connection of the electronic circuit module is disposed on the bottom surface (opposite surface to the mother board) of the electronic circuit module, even if high temperature air is blown to the electronic circuit module, The intervening solder cannot be efficiently heated. For this reason, conventionally, it is difficult not only to quickly carry out a repair work for removing the electronic circuit module from the motherboard, but also the space in the shield cover of the electronic circuit module and the motherboard in the vicinity of the module are heated during the work. Therefore, there is a risk of deteriorating reliability by inducing thermal destruction at an undesired location.

  The present invention has been made in view of such a state of the art, and an object of the present invention is to provide an electronic device that can be easily and quickly repaired after being mounted and removed from the mother board without causing undesired thermal destruction. It is to provide a circuit module.

  In order to achieve the above object, according to the present invention, an insulating substrate having a circuit element mounted on one surface and an electrode group for external connection disposed on the other surface is solder-connected to the motherboard. In the electronic circuit module to be mounted, a plurality of annular conductive portions that individually surround the electrode group and a plurality of connection conductive portions that connect the adjacent annular conductive portions to the other surface of the insulating substrate. In addition to providing a mesh-like conductive pattern, the heating terminal portion extending from the mesh-like conductive pattern is provided on the side surface of the insulating substrate.

  The electronic circuit module configured in this way can efficiently heat the mesh-like conductive pattern by bringing a heating jig into contact with the heating terminal portion during repair work to be removed from the motherboard after mounting. The solder adhering to the electrode surrounded by the part can be melted in a short time. Therefore, this electronic circuit module can be repaired easily and quickly, and the circuit elements on the insulating substrate and the nearby motherboard do not become so hot during the repairing work, so there is a risk of causing undesired thermal destruction. Few.

  In the above configuration, when the insulating substrate has a rectangular shape in plan view and heating terminal portions are respectively provided on the four side surfaces of the insulating substrate, the four-sided conductive pattern is substantially even from four sides during repair work. Since heat can be transmitted, all the annular conductive parts can be heated extremely efficiently, and workability is further improved.

  In the above configuration, when the grounding electrode provided on the surface of the insulating substrate facing the mother board is connected to the mesh conductive pattern, the mesh conductive pattern and the heating terminal are operated as the ground conductor layer. Therefore, the ground function can be strengthened.

  Further, in the above configuration, when the shield cover placed on the insulating substrate covers the circuit element and the peripheral portion of the shield cover is soldered to the land provided on the insulating substrate, It is preferable to provide a heating terminal portion at a position separated from the shield cover and the land, and this makes it difficult for heat to be transferred from the heating terminal portion to the shield cover during repair work. However, the thermal destruction of the circuit elements can be avoided more easily.

  In the above configuration, each external connection electrode group is provided with solder bumps. If the solder bumps are connected to the motherboard by solder bumps, they cannot be seen from the outside when mounted. Solder bumps can be melted in a short time during repair work because the electrode group can be soldered to the motherboard with high accuracy and the heat of the heating terminal part is efficiently transmitted to each annular conductive part surrounding each electrode. Can do.

  According to the electronic circuit module of the present invention, the heat applied to the heating terminal portion can be efficiently conducted to the mesh-like conductive pattern, so that the external portion surrounded by the annular conductive portion can be removed during the repair work to be removed from the motherboard after mounting. The solder adhering to the connection electrode can be melted in a short time. Therefore, this electronic circuit module has the convenience that the repair work after mounting can be performed easily and quickly, and the circuit elements on the insulating substrate and the nearby motherboard do not become so hot during the repair work, which is undesirable. There is a remarkable effect that there is little risk of inducing thermal destruction.

  An embodiment of the invention will be described with reference to the drawings. FIG. 1 is an external view of an electronic circuit module according to an embodiment of the present invention, FIG. 2 is a bottom view of the electronic circuit module, and FIG. FIG. 4 is an explanatory view showing a state in which the electronic circuit module is mounted on a mother board.

  The electronic circuit module 1 shown in these drawings is an RF module incorporated in a high-frequency circuit mechanism such as a mobile phone, and is mainly composed of an insulating substrate 2, a group of circuit elements 3 and a shield cover 4. The insulating substrate 2 is a rectangular ceramic substrate in plan view with good thermal conductivity, and a plurality of circuit elements 3 are mounted on the insulating substrate 2. These circuit elements 3 are connected to circuit patterns and through holes (not shown) provided on the insulating substrate 2. As shown in FIG. 2, the bottom surface 2a of the insulating substrate 2 is provided with a group of electrodes 5 for external connection in the inner region from the peripheral edge, and the grounding electrodes 5a are located at the four corners of the group of electrodes 5. ing. A solder bump 10 is attached to each electrode 5 including the ground electrode 5a. These solder bumps 10 are arranged as a so-called ball grid array (BGA). When the electronic circuit module 1 is mounted on the mother board 20, the group of electrodes 5 and the corresponding figure on the mother board 20 side are shown. An electrode group (not shown) is soldered by solder bumps 10 (see FIG. 4). The shield cover 4 made of sheet metal is placed on the insulating substrate 2 to cover the circuit element 3 group, and the periphery of the shield cover 4 is soldered to a plurality of lands 6 provided on the insulating substrate 2. .

  The bottom surface 2a of the insulating substrate 2 includes a plurality of annular conductive portions 7a that individually surround the group of electrodes 5 and a plurality of connecting conductive portions 7b that connect adjacent annular conductive portions 7a and extend in a lattice shape. A mesh-like conductive pattern 7 is provided (see FIG. 2). All the electrodes 5 except the grounding electrode 5a are not electrically connected to the mesh-like conductive pattern 7, but only the grounding electrode 5a in the group of electrodes 5 is connected to the mesh-like conductive pattern 7. In addition, horizontally long heating terminal portions 8 are provided in regions extending from the central portions of the four side surfaces 2b of the insulating substrate 2 to the peripheral portions of the bottom surface 2a. These four heating terminal portions 8 are all extended from the mesh-like conductive pattern 7, and both 7 and 8 are formed as a continuous pattern. As shown in FIG. 3, the peripheral edge portion or land 6 of the shield cover 4 located in the vicinity of the four sides on the insulating substrate 2 and the heating terminal portion 8 provided on the side surface 2 b of the insulating substrate 2 are slightly different. There is a gap between them.

  When the electronic circuit module 1 configured in this way is mounted on the mother board 20, the electronic circuit module 1 is mounted at a predetermined position on the mother board 20, and the solder bumps 10 are melted in a reflow furnace or the like. As a result, the externally connected electrodes 5 and the corresponding electrode group on the mother board 20 side are electrically and mechanically connected to the solder bumps 10 which are cooled and solidified after melting.

  Further, when a problem is found in the performance of the electronic circuit module 1 or its mounting state after mounting, a repair operation is performed in which only the electronic circuit module 1 is removed from the motherboard 20 and replaced. In such repair work, as shown in FIG. 4, a heating jig 30 having four arm portions 31 that can be opened and closed is used, and each heating portion 32 provided at the tip of each arm portion 31 is replaced with each of the insulating substrates 2. Heating is performed by contacting the heating terminal 8 provided on the side surface 2b. Since these four heating terminal portions 8 are continuous with the mesh conductive pattern 7, the heat supplied to each heating terminal portion 8 wraps around the bottom surface 2 a of the insulating substrate 2 and quickly reaches the mesh conductive pattern 7. It is transmitted. That is, by directly heating each heating terminal portion 8 with the heating jig 30, the mesh-like conductive pattern 7 can be efficiently heated from four directions, so that all the annular conductive portions surrounding each electrode 5 are provided. 7a becomes a high temperature in a short time, and as a result, the solder bump 10 adhering to each electrode 5 can be melted in a short time. When the solder bumps 10 interposed between the insulating substrate 2 and the mother board 20 are melted in this way, the electronic circuit module 1 sandwiched between the plurality of arm portions 31 is lifted together with the arm portions 31, thereby the electronic circuit module 1. Can be easily removed from the motherboard 20.

  When the electronic circuit module 1 is mounted on the mother board 20 again after the repair work, the heating jig is attached to each heating terminal portion 8 of the electronic circuit module 1 mounted at a predetermined position on the mother board 20 as described above. The heating bumps 30 may be brought into contact with each other and heated, so that the solder bumps 10 interposed between the insulating substrate 2 and the mother board 20 can be melted in a short time.

  As described above, the electronic circuit module 1 according to this embodiment can efficiently conduct the heat applied to the heating terminal portion 8 to the mesh-like conductive pattern 7, so that the repair work for removing it from the motherboard 20 after mounting is performed. Sometimes, the solder bump 10 attached to the external connection electrode 5 surrounded by the annular conductive portion 7a can be melted in a short time. Therefore, the electronic circuit module 1 has the convenience that the repair work after mounting can be performed easily and quickly, and the circuit element 3 on the insulating substrate 2 and the mother board 20 in the vicinity thereof are not so hot during the repair work. Less risk of inducing undesired thermal destruction. In addition, the peripheral portion of the shield cover 4 and the land 6 are disposed in the vicinity of the heating terminal portion 8, but there is a slight gap between the shield cover 4 and the land 6 and the adjacent heating terminal portion 8. Therefore, heat is hardly transmitted from the heating terminal 8 to the shield cover 4 during the repair work, and therefore the space in the shield cover 4 does not become so high.

  Further, in the electronic circuit module 1 according to the present embodiment example, since the ground electrode 5a is connected to the mesh conductive pattern 7, the mesh conductive pattern 7 and the heating terminal portion 8 are operated as a ground conductor layer. It is possible to strengthen the ground function.

  In the embodiment described above, the heating terminal portion 8 is provided on each of the four side surfaces 2b of the insulating substrate 2, and all the four heating terminal portions 8 are heated during the repair work, whereby the mesh-like conductive pattern 7 is provided. Although heat is transmitted almost uniformly from the four sides, the mesh conductive pattern 7 can be efficiently heated only by heating the two heating terminal portions 8 existing on the pair of substantially parallel side surfaces 2b.

  In the above embodiment, the solder bumps 10 are attached to the external connection electrodes 5 arranged on the insulating substrate 2 of the electronic circuit module 1, but the solder is applied to the corresponding electrodes on the mother board 20 side. The bumps 10 can be provided, and in any case, the group of electrodes 5 that cannot be seen from the outside when mounted can be soldered to the mother board 20 with high accuracy, and each annular conductive portion 7a surrounding each electrode 5 is provided. On the other hand, since the heat of the heating terminal portion 8 is transmitted efficiently, the solder bump 10 can be melted in a short time during the repair work.

1 is an external view of an electronic circuit module according to an embodiment of the present invention. It is a bottom view of the electronic circuit module. It is sectional drawing of this electronic circuit module. It is explanatory drawing which shows the state which mounted this electronic circuit module on the motherboard.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Electronic circuit module 2 Insulation board | substrate 2a Bottom face 2b Side face 3 Circuit element 4 Shield cover 5 Electrode 5a (For external connection) 5a Grounding electrode 6 Land 7 Mesh-like conductive pattern 7a Annular conductive part 7b Connection conductive part 8 Heating terminal part 10 Solder bump 20 Motherboard 30 Heating jig

Claims (5)

An electronic circuit module comprising an insulating substrate having a circuit element mounted on one surface and an electrode group for external connection disposed on the other surface, and mounted by soldering the electrode group to a motherboard,
Provided on the other surface of the insulating substrate is a mesh-like conductive pattern including a plurality of annular conductive portions that individually surround the electrode group and a plurality of connection conductive portions that connect the adjacent annular conductive portions. An electronic circuit module, wherein a heating terminal portion extending from a mesh-like conductive pattern is provided on a side surface of the insulating substrate.   2. The electronic circuit module according to claim 1, wherein the insulating substrate has a rectangular shape in plan view, and the heating terminal portions are provided on four side surfaces of the insulating substrate, respectively.   3. The electronic circuit module according to claim 1, wherein a grounding electrode provided on the other surface of the insulating substrate is connected to the mesh-like conductive pattern.   The land according to claim 1, wherein a shield cover placed on the insulating substrate covers the circuit element, and a peripheral portion of the shield cover is provided on the insulating substrate. An electronic circuit module, wherein the heating terminal portion is provided at a position spaced from the shield cover and the land.   5. The method according to claim 1, wherein each of the electrode groups is provided with a solder bump, and the electrode group is solder-connected to the mother board by the solder bump. Electronic circuit module.

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