JP2009302315A - Muliti-layer substrate and gps communication apparatus equipped with the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a multi-layer substrate that can stably connect an electronic substrate and an electronic substrate loaded on it and to provide a GPS communication apparatus equipped with the multi-layer substrate. <P>SOLUTION: The multi-layer substrate 3 is constituted of a first substrate 31 such as a printed board, a conductive metal layer 33, a solder mask 32 and a second substrate 34 such as a module substrate in order from the lowest layer. Terminals 35 are arranged at end parts of the second substrate 34. The terminals 35 are connected to the conductive metal layer 33 by solder parts H. A first opening part 37 is formed in a region confronted with the second substrate 34 and second opening parts 36 in positions corresponding to the terminals 35 in the solder mask 32. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a multilayer substrate and a GPS (Global Positioning System) communication apparatus including the multilayer substrate, and more particularly to a multilayer substrate having an electronic substrate mounted on a printed circuit board.

  An electronic board may be mounted on the printed board. Electronic boards include printed circuit boards or module boards such as frequency filters. The electronic board is connected to the printed board by soldering the cross-sectional through-hole portion of the electronic board.

  FIG. 5A is an example of a conventional multilayer substrate, and is a cross-sectional view showing an ideal state in which the warpage of the second substrate is not considered, and FIG. 5B is a top view thereof. As shown in FIGS. 5A and 5B, the multilayer substrate 1 includes a first substrate 11 such as a printed circuit board, a conductive metal layer 13, a solder mask 12, and a module substrate in order from the lower layer. The second substrate 14. A terminal 15 is provided at the end of the second substrate 14. The terminal 15 is connected to the conductive metal layer 13 by a solder portion H.

  The first substrate 11 is formed with the conductive metal layer 13 on the surface of the insulating substrate or on the surface thereof and the inside thereof, based on the circuit design, by means of the conductive metal layer 13. The solder mask 12 is made of a resist ink such as a thermosetting epoxy resin film. A portion of the conductive metal layer that needs to be soldered is exposed, and a portion that does not need to be soldered is formed on the conductive metal layer so that the solder is not attached. Therefore, the opening 16 is formed at a position where the solder portion H is provided. The second substrate 14 is a single printed circuit board or a module substrate such as a frequency filter.

  FIG. 6 is a view showing a state in which a warp is generated when the second substrate 24 is soldered by reflow, which is a conventional multilayer substrate. As shown in FIG. 6, the second substrate 24 is warped in a convex shape downward. Therefore, the terminal 25 is separated from the opening 26 of the solder mask 22. When soldering is performed in this state, even if the second substrate 25 and the conductive metal layer 23 cannot be connected, or even if they can be connected, the solder joint strength is weak so that the second substrate 25 is disconnected during use. It causes a defect. In some cases, the second substrate 24 may warp upward, but in this case, since the terminals 25 are in contact with the conductive metal layer 23, the bonding failure of the second substrate 24 does not occur.

  Furthermore, FIG. 7 shows an example of a conventional multilayer substrate in which a metal shield is disposed on the second substrate. FIG. 7A is a cross-sectional view, and FIG. 7B is a top view thereof. FIG. 7 shows an ideal state in which the warpage of the second substrate and the metal shield is not taken into account, as in FIG. Other than the metal shield 59 is the same as that of FIG. Since the metal shield 59 prevents leakage of electromagnetic waves, a multilayer substrate having an electromagnetic wave prevention effect is obtained.

As a prior document disclosing such a module substrate connection method, there is Patent Document 1. Patent Document 1 discloses a method of electrically and mechanically connecting a module board on which a plurality of individual parts are mounted to a mother board. Further, Patent Document 2 is a prior art document that discloses a solder bump arrangement method that is unlikely to cause poor bonding, and Patent Document 3 is a prior art document that discloses a method for regenerating a solder bump.
JP-A-8-316700 Japanese Patent Laid-Open No. 9-162531 Japanese Patent Laid-Open No. 10-173001

  When soldering is performed by reflowing the module substrate, the module substrate may be warped or twisted. In that case, the cross-sectional through-hole portion of the module board cannot be connected to the terminal on the printed board. As a result, bonding failure or operation failure occurs. Further, when the metal shield is attached on the electronic board, the linear expansion coefficient of the electronic board is larger than the linear expansion coefficient of the metal shield, so that it tends to warp downward.

  The connection method of the module substrate described in Patent Document 1 minimizes the amount of sealing resin for sealing the semiconductor chip in order to suppress warpage of the module substrate. However, this method cannot sufficiently eliminate the influence of the warp generated on the module substrate. In the method for arranging solder bumps described in Patent Document 2, the arrangement of solder bumps is made dense in order to suppress warpage of the module substrate. However, even with this method, the influence of the warp generated on the module substrate cannot be sufficiently eliminated.

  In the method for regenerating solder bumps described in Patent Document 3, solder bumps are re-formed only at the corresponding locations of defective semiconductor elements. In this case, the module substrate is heated a plurality of times when forming solder bumps or mounting a new semiconductor element. Therefore, the module substrate is easily warped due to the influence of heat.

  The present invention has been made to solve the above-described problems, and provides a multilayer substrate and a GPS communication apparatus including the multilayer substrate that can stably connect the electronic substrate and the electronic substrate mounted thereon. The purpose is to do.

  A multilayer substrate according to the present invention includes a first substrate, a conductive metal layer provided on an upper surface of the first substrate, a second substrate disposed above the conductive metal layer and having a terminal at an end, A first opening provided between the conductive metal layer and the second substrate and formed in a region facing the second substrate; and a second opening formed at a position corresponding to the terminal. And a solder part that is provided in the second opening of the solder mask and connects the terminal of the second substrate and the conductive metal layer.

  According to this multilayer substrate, the opening is provided in the solder mask in the region facing the second substrate. Therefore, when the downward convex warpage occurs in the second substrate, the warped portion is accommodated in the opening. As a result, the gap between the terminal of the second substrate and the conductive metal layer can be reduced, the influence of warpage can be reduced, and poor bonding can be reduced.

  The conductive metal layer may have an opening in a region facing the first opening of the solder mask. According to this multilayer substrate, openings are provided in the solder mask and the conductive metal layer located immediately below the mounting position of the second substrate. Therefore, when the downward convex warpage occurs in the second substrate, the warped portion is accommodated in the opening. The influence of the warp of the substrate can be further reduced as compared with the case where the opening is provided only in the solder mask. As a result, the gap between the terminal of the second substrate and the conductive metal layer can be further reduced, the influence of warpage can be reduced, and the solder joint strength can be increased.

  The multilayer substrate according to the present invention may further include a metal shield on the upper surface of the second substrate. In this case, leakage of electromagnetic waves is prevented by the metal shield, and a multilayer substrate having an electromagnetic wave preventing effect is obtained. The first substrate may be a printed circuit board.

  In the multilayer substrate according to the present invention, the second substrate may be a module substrate. Further, among the module substrates, a GPS module substrate may be used. Moreover, you may utilize the multilayer substrate concerning this invention for a GPS communication apparatus.

  ADVANTAGE OF THE INVENTION According to this invention, the multilayer substrate which can connect the electronic substrate and the electronic substrate mounted on it stably can be provided.

  Hereinafter, a multilayer substrate in an embodiment based on the present invention will be described with reference to the drawings.

Embodiment 1
FIG. 1 shows a cross-sectional view of a multilayer substrate according to Embodiment 1 of the present invention. As shown in FIG. 1, the multilayer substrate 3 of the present invention includes a first substrate 31 such as a printed circuit board, a conductive metal layer 33, a solder mask 32, and a second substrate 34 such as a module substrate in order from the lower layer. It is configured. A terminal 35 is provided at the end of the second substrate 34. The terminal 35 is connected to the conductive metal layer 33 by the solder portion H. The conductive metal layer 33 is, for example, a copper foil having a thickness of 0.018 mm, a copper plating having a thickness of 0.015 mm or more, a nickel plating having a thickness of 2.55 to 6.35 μm, and a thickness of 0.05 to 0.20 μm. Gold plating or the like may be used as the management value. In the solder mask 32, a first opening 37 is formed in a region facing the second substrate 34, and a second opening 36 is formed at a position corresponding to the terminal 35. For example, the opening may be formed by patterning using a printing method.

  Warpage of the second substrate 34 that occurs when soldering to the second opening 36 is accommodated in the first opening 37. Therefore, the gap between the terminal 35 and the conductive metal layer 32 can be reduced compared to the case where the first opening 37 is not provided. As a result, it is possible to reduce the occurrence of defective bonding or malfunction during use.

Embodiment 2
FIG. 2 is a sectional view of a multilayer substrate according to the second embodiment of the invention. As shown in FIG. 2, the multilayer substrate 4 according to the present invention includes, in order from the lower layer, a first substrate 41 such as a printed circuit board, a conductive metal layer 43, a solder mask 42, and a second substrate 44 such as a module substrate. It is configured. A terminal 45 is provided at the end of the second substrate 44. The terminal 45 is connected to the conductive metal layer 43 by a solder portion H. The conductive metal layer 43 is, for example, a copper foil having a thickness of 0.018 mm, a copper plating having a thickness of 0.015 mm or more, a nickel plating having a thickness of 2.55 to 6.35 μm, and a thickness of 0.05 to 0.20 μm. Gold plating or the like may be used as the management value.

A first opening 47 is formed in the region facing the second substrate 44, and a second opening 46 is formed in the solder mask 42 at a position corresponding to the terminal 45. Further, an opening 48 is formed in the conductive metal layer 43 in a region facing the first opening 47. The solder mask opening may be formed by patterning, for example, by a printing method. As a method for forming the opening of the conductive metal layer, for example, ferric chloride (FeCl ₃ ) may be used for etching.

  Warpage of the second substrate 44 that occurs when soldering is contained in the first opening 47 of the solder mask 42 and the opening 48 of the conductive metal layer 43. In this case, warpage can be further reduced as compared with the case where the opening is provided only in the solder mask 42. Therefore, the gap between the terminal 45 and the conductive metal layer 42 can be further reduced. As a result, it is possible to further reduce the occurrence of defective bonding or defective operation during use. Moreover, since the contact length between the terminal 45 and the solder portion H can be ensured, the solder joint strength can be increased.

Embodiment 3
FIG. 3 shows a cross-sectional view of a multilayer substrate according to Embodiment 3 of the invention. As shown in FIG. 3, the multilayer substrate 6 of the present invention includes, in order from the lower layer, a first substrate 61 such as a printed circuit board, a conductive metal layer 63, a solder mask 62, and a second substrate 64 such as a module substrate. The metal shield 69 is used. A terminal 65 is provided at the end of the second substrate 64. The terminal 65 is connected to the conductive metal layer 63 by the solder portion H. The conductive metal layer 63 is, for example, a copper foil having a thickness of 0.018 mm, a copper plating having a thickness of 0.015 mm or more, a nickel plating having a thickness of 2.55 to 6.35 μm, and a thickness of 0.05 to 0.20 μm. Gold plating or the like may be used as the management value.

  A first opening 67 is formed in a region facing the second substrate 64, and a second opening 66 is formed in the solder mask 62 at a position corresponding to the terminal 65. The opening may be formed by patterning using a printing method, for example. Since the metal shield 69 prevents leakage of electromagnetic waves, a multilayer substrate having an electromagnetic wave prevention effect is obtained.

  In general, the linear expansion coefficient of the second substrate 64 is larger than the linear expansion coefficient of the metal shield 69. For this reason, the second substrate 64 is likely to be warped, and when the second substrate 64 is warped downward, the gap between the terminal 65 and the conductive metal layer 62 is increased. Therefore, the warp of the second substrate 64 that occurs when soldering to the second opening 66 is greater than when the metal shield 69 is not disposed. This warpage is accommodated in the first opening 67. Therefore, the gap between the terminal 65 and the conductive metal layer 62 can be reduced as compared with the case where the first opening 67 is not provided. As a result, it is possible to reduce the occurrence of defective bonding or malfunction during use.

Embodiment 4
FIG. 4 shows a cross-sectional view of a multilayer substrate according to Embodiment 4 of the present invention. As shown in FIG. 4, the multilayer substrate 7 of the present invention includes, in order from the lower layer, a first substrate 71 such as a printed circuit board, a conductive metal layer 73, a solder mask 72, and a second substrate 74 such as a module substrate. The metal shield 79 is used. A terminal 75 is provided at the end of the second substrate 74. The terminal 75 is connected to the conductive metal layer 73 by the solder portion H. The conductive metal layer 73 is, for example, a copper foil having a thickness of 0.018 mm, a copper plating having a thickness of 0.015 mm or more, a nickel plating having a thickness of 2.55 to 6.35 μm, and a thickness of 0.05 to 0.20 μm. Gold plating or the like may be used as the management value.

A first opening 77 is formed in the area facing the second substrate 74, and a second opening 76 is formed in the solder mask 72 at a position corresponding to the terminal 75. Further, an opening 78 is formed in the conductive metal layer 73 in a region facing the first opening 77. The solder mask opening may be formed by patterning, for example, by a printing method. As a method for forming the opening of the conductive metal layer, for example, ferric chloride (FeCl ₃ ) may be used for etching. Since the metal shield 79 prevents leakage of electromagnetic waves, a multilayer substrate having an electromagnetic wave prevention effect is obtained.

  In general, the linear expansion coefficient of the second substrate 74 is larger than the linear expansion coefficient of the metal shield 79. Therefore, the second substrate 74 is likely to be warped, and when the second substrate 74 is warped downward, the gap between the terminal 75 and the conductive metal layer 72 is increased. Therefore, the warp of the second substrate 74 that occurs when soldering to the second opening 76 is greater than when the metal shield 79 is not disposed.

  This warpage is contained in the first opening 77 of the solder mask 72 and the opening 78 of the conductive metal layer 73. In this case, the warp can be further reduced as compared with the case where the opening is provided only in the solder mask 72. Therefore, the gap between the terminal 75 and the conductive metal layer 72 can be further reduced. As a result, it is possible to further reduce the occurrence of defective bonding or defective operation during use. Moreover, since the contact length between the terminal 75 and the solder portion H can be ensured, the solder joint strength can be increased.

  In the above embodiment, for example, a GPS module substrate may be used as the module substrate. The effects of the present invention can also be obtained by using the multilayer substrate in the above embodiment for a GPS communication device.

  In addition, the said embodiment disclosed this time is an illustration in all the points, Comprising: It does not become the basis of limited interpretation. Therefore, the technical scope of the present invention is not interpreted only by the above-described embodiment, but is defined based on the description of the scope of claims. Further, all modifications within the meaning and scope equivalent to the scope of the claims are included.

1 is a cross-sectional view of a multilayer substrate according to Embodiment 1 of the present invention. FIG. 3 is a cross-sectional view of a multilayer substrate according to Embodiment 2 of the present invention. FIG. 5 is a cross-sectional view of a multilayer substrate according to Embodiment 3 of the present invention. FIG. 9 is a cross-sectional view of a multilayer substrate according to Embodiment 4 of the present invention. It is a figure for demonstrating the structure of an example of the conventional multilayer substrate. It is the conventional multilayer board, Comprising: When soldering an electronic board by reflow, it is the figure which showed the state which the curvature has generate | occur | produced. It is a figure for demonstrating the structure of an example of the conventional multilayer substrate.

Explanation of symbols

  1, 2, 3, 4, 5, 6, 7 Multi-layer substrate, 11, 21, 31, 41, 51, 61, 71 Printed circuit board, 12, 22, 32, 42, 52, 62, 72 Solder mask, 13 , 23, 33, 43, 53, 63, 73 Conductive metal layer, 14, 24, 34, 44, 54, 64, 74 Electronic substrate, 15, 25, 35, 45, 55, 65, 75 Terminal, 16, 26 36, 46, 56, 66, 76 Second opening, 37, 47, 67, 77 First opening, 48, 78 opening, 59, 69, 79 Metal shield, H solder part.

Claims (7)

A first substrate;
A conductive metal layer provided on an upper surface of the first substrate;
A second substrate disposed above the conductive metal layer and having a terminal at an end;
A first opening formed between the conductive metal layer and the second substrate and formed in a region facing the second substrate; and a second opening formed at a position corresponding to the terminal. A solder mask having,
A multilayer substrate comprising a solder portion provided in a second opening of the solder mask and connecting a terminal of the second substrate and the conductive metal layer.   2. The multilayer substrate according to claim 1, wherein the conductive metal layer has an opening in a region facing the first opening of the solder mask.   The multilayer substrate according to claim 1, further comprising a metal shield on an upper surface of the second substrate.   The multilayer substrate according to claim 1, wherein the first substrate is a printed circuit board.   The multilayer substrate according to claim 1, wherein the second substrate is a module substrate.   The multilayer substrate according to claim 1, wherein the second substrate is a GPS module substrate.   The GPS communication apparatus provided with the multilayer substrate in any one of Claims 1-6.

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