Module

Abstract

A module 1 comprises: a substrate 15 in which a component mounting land 20 and a resist layer 30 are provided on a surface 16 of the substrate 15; and an electronic component 100 mounted on the component mounting land 20. The module 1 is characterized by, in an electronic component lower space 50 which is a space between a bottom surface 106 of the electronic component 100 and the surface 16 of the substrate 15, having a resist thinnest portion 40 in which the resist layer 30 is not present on the surface 16 of the substrate 15 or a thickness of the resist layer 30 is smaller than a thickness of the resist layer 30 outside the component mounting land 20.

Description

Module

[0001] The present invention relates to a module.

[0002] Modules are known in which electronic components are soldered onto component mounting lands provided on the surface of a substrate. In such modules, when the spacing between adjacent electronic components becomes narrow or the electronic components are miniaturized, solder shorts may occur between the component mounting lands or between the terminals of the electronic components. In order to prevent solder shorts, a resist layer may be provided on the surface of the component mounting lands or on the surface of the substrate.

[0003] Patent Document 1 (FIG. 1A, etc.) shows a structure in which the height of the resist beside the solder bumps is high. It is said that by adopting this structure, shorts and bridges between the solder bumps can be prevented.

[0004] U.S. Patent Application Publication No. 2023 / 0061167

[0005] In recent years, from the perspective of preventing solder shorts, the amount of solder used has been on a decreasing trend. When the amount of solder used is small, if the mounting position of the electronic component shifts slightly, the bonding strength of the electronic component to the component mounting land may not be ensured sufficiently.

[0006] Here, in the structure described in Patent Document 1, since the height of the resist beside the solder bumps is high, when the amount of solder used is small and the mounting position of the electronic component shifts, poor bonding of the electronic component is likely to occur.

[0007] Further, after mounting the electronic component on the substrate, a sealing resin is injected to seal (mold) the electronic component. When the amount of solder used is small, the space between the substrate and the bottom surface of the electronic component becomes narrow, so the sealing resin may not enter the above space, and the sealing may become insufficient.

[0008] The present invention has been made to solve the above problems, and an object thereof is to provide a module that can be well sealed with a sealing resin while having a resist layer for preventing solder shorts.

[0009] One aspect of the module of the present invention is a module comprising a substrate having component mounting lands and a resist layer on its surface, and an electronic component mounted on the component mounting lands, characterized in that in the space below the electronic component, which is the space between the bottom surface of the electronic component and the surface of the substrate, there is a resist thinning area where the resist layer is absent from the surface of the substrate, or where the thickness of the resist layer is thinner than the thickness of the resist layer outside the component mounting lands.

[0010] Another aspect of the module of the present invention is a module comprising a substrate having component mounting lands and a resist layer on its surface, and an electronic component mounted on the component mounting lands, wherein in the electronic component lower space, which is the space between the bottom surface of the electronic component and the surface of the substrate, resist-coated wiring, which is wiring covered with resist, is arranged on the surface of the substrate, and in a top view, a plurality of component mounting lands are provided for one electronic component, and in the electronic component lower space between the component mounting lands, there is a resist thinning area on the surface of the substrate where the resist layer is absent, or where the thickness of the resist layer is thinner than the thickness of the resist layer outside the component mounting lands.

[0011] According to the present invention, it is possible to provide a module that can be properly sealed with a sealing resin while also having a resist layer for preventing solder short circuits.

[0012] Figure 1A is a schematic cross-sectional view showing an example of a module. Figure 1B is a top view of the module. Figure 1C is a top view showing the position of the thinnest part of the resist and the extended part connected, with the electronic components removed from Figure 1B. Figure 1D is a schematic cross-sectional view showing an example where the electronic components of the module shown in Figure 1A are sealed with sealing resin. Figure 2 is a schematic cross-sectional view showing an example of a module where the thinnest part of the resist is the part where the thickness of the resist layer is thinner than the thickness of the resist layer outside the component mounting land. Figure 3 is a schematic top view showing an example of a module. Figure 4A is a schematic cross-sectional view showing an example of a module. Figure 4B is a top view of the module. Figure 5A is a schematic cross-sectional view showing an example of a module. Figure 5B is a top view of the module. Figure 6 is a schematic top view showing another example of a module. Figure 7A is a schematic cross-sectional view showing an example of a module. Figure 7B is a top view of the module. Figure 8 is a schematic top view showing another example of a module. Figure 9 is a schematic top view showing another example of a module. Figure 10 is a schematic top view showing another example of a module. Figure 11 is a schematic top view showing another example of a module.

[0013] The modules of the present invention will be described below. However, the present invention is not limited to the following configurations and can be modified and applied as appropriate without changing the essence of the invention. Furthermore, a combination of two or more desirable configurations of each embodiment of the present invention described below also constitutes the present invention.

[0014] First, the module of the present invention will be described. Figure 1A is a schematic cross-sectional view showing an example of the module.

[0015] Figure 1A shows module 1. Module 1 has a substrate 15, on which component mounting lands 20 and a resist layer 30 are provided, with a portion of the resist layer 30 covering the surface of the component mounting lands 20.

[0016] Multiple (two) component mounting lands 20 are provided laterally (in the direction of arrow X in Figure 1A) for one of the aforementioned electronic components. The component mounting land on the left is called component mounting land 20a, and the component mounting land on the right is called component mounting land 20b.

[0017] An electronic component 100 is mounted on the component mounting land 20 via solder 60. Specifically, the external electrodes 110 of the electronic component 100 are connected to the component mounting land 20 via solder 60. For example, a Sn-Ag-Cu-based Pb-free solder is used as the solder 60, but it is not limited to this. In the electronic component 100 shown in Figure 1A, the external electrodes 110 are provided across the bottom, end, and top surfaces of the electronic component 100, but the method of forming the external electrodes is not particularly limited.

[0018] The type of substrate 15 is not particularly limited, and examples include resin substrates in which the insulating layer constituting the substrate is made of resin (glass epoxy resin substrate, BT (bismaleimidotriazine resin) substrate, polyimide resin substrate, LCP (liquid crystal polymer) substrate, etc.), or ceramic substrates (LTCC substrate) which are low-temperature sintered ceramic materials.

[0019] The substrate may be provided with pattern conductors and via conductors, which are formed using a metallic material selected from, for example, Cu and Cu alloys. However, the material of the pattern conductors and via conductors is not limited to these. It is also preferable that the component mounting lands 20 provided on the surface of the substrate 15 are formed using the same material as the pattern conductors and via conductors. Furthermore, the substrate may be either a multilayer substrate or a single-layer substrate.

[0020] The material of the resist layer 30 is not particularly limited, and any resist material known as solder resist can be used.

[0021] The electronic component 100 is preferably a chip component such as a multilayer capacitor, a multilayer inductor, or various filters, or a semiconductor component such as various ICs or memory.

[0022] The space between the bottom surface 106 of the electronic component and the surface 16 of the substrate is the electronic component lower space 50. In the module of the present invention, the thinnest resist portion is provided in the electronic component lower space. The thinnest resist portion is a portion where there is no resist layer on the surface of the substrate, or a portion where the thickness of the resist layer is thinner than the thickness of the resist layer outside the component mounting land.

[0023] In module 1 shown in Figure 1A, the area in the space 50 below the electronic component where the resist layer 30 is not present on the surface 16 of the substrate is the thinnest resist area 40.

[0024] The explanation for the case where the thinnest part of the resist is a part where the thickness of the resist layer is thinner than the thickness of the resist layer outside the component mounting land will be explained later.

[0025] The space beneath the electronic component is where the sealing resin is injected. If a thick resist layer is present on the substrate surface in this area, the sealing resin will have difficulty being injected into the space beneath the electronic component, resulting in insufficient sealing of the electronic component with the sealing resin. Therefore, a thinnest resist layer area is provided in the space beneath the electronic component, allowing the sealing resin to be injected into the space from this thinnest resist layer. This effect is particularly pronounced when the thinnest resist layer area is a part of the substrate surface where no resist layer exists. In this way, it is possible to create a module that provides a resist layer to prevent solder shorts while also achieving good sealing with the sealing resin.

[0026] The distance from the surface of the thinnest part of the resist to the bottom surface of the electronic component at the thinnest part of the resist (double arrow t in Figure 1A). １The maximum diameter of the resin filler (shown as indicated by ) is preferably greater than the maximum diameter of the resin filler contained in the encapsulating resin to be injected. It is even more preferable that it is 5 μm or more greater than the maximum diameter of the resin filler contained in the encapsulating resin. For example, if the maximum diameter of the resin filler is 25 μm, it is preferable that the distance from the surface of the thinnest part of the resist to the bottom surface of the electronic component exceeds 25 μm, and more preferably exceeds 30 μm. If the maximum diameter of the resin filler is 10 μm, it is preferable that the distance from the surface of the thinnest part of the resist to the bottom surface of the electronic component exceeds 10 μm, and more preferably exceeds 15 μm. When the relationship between the distance from the surface of the thinnest part of the resist to the bottom surface of the electronic component and the maximum diameter of the resin filler is as described above, the injection of the encapsulating resin into the space below the electronic component can be performed more effectively.

[0027] In the module of the present invention, the thickness of the resist layer changes outside the component mounting land, and it is preferable that the thickness of the resist layer in the land proximity region in contact with the component mounting land is thinner than the thickness of the resist layer in the region outside the land proximity region. This will be explained with reference to Figure 1A.

[0028] Refer to the configuration around the component mounting land 20a shown on the left in Figure 1A. The area near the left edge of the component mounting land 20a is covered with a resist layer 30. Covering this area with the resist layer 30 prevents the solder 60 from flowing to the outside (left side) of the component mounting land.

[0029] The area outside (to the left of) the component mounting land 20a and in contact with the component mounting land 20a is defined as the land proximity region 21a (indicated by a double arrow 21a in Figure 1A). The thickness of the resist layer 31a in the land proximity region 21a is indicated by a double arrow t in Figure 1A. ２ (shown by double arrow t in Figure 1A) is the thickness of the resist layer 32a in the region 22a outside the land proximity region 21a (shown by double arrow t in Figure 1A). ３ It becomes thinner than (shown by).

[0030] As shown in Figure 1A, when the thickness of the resist layer 30 increases as it moves away from the component mounting land 20a, the region outside (to the left of) the component mounting land 20a, in contact with the component mounting land 20a, and where the resist layer 30 is thinner, is defined as the land proximity region 21a. Furthermore, the region where the thickness of the resist layer 30 is thicker than the thickness of the resist layer 30 in the land proximity region 21a is defined as the region 22a outside the land proximity region 21a. Note that the land proximity region does not include the portion of the resist layer covering the component mounting land (this resist layer is thinner than the resist layer in the land proximity region).

[0031] In Figure 1A, the thickness of the resist layer increases towards the outside of the drawing, and the thickness of the resist layer changes in a step-like manner. This change in the thickness of the resist layer is discontinuous. Alternatively, the change in the thickness of the resist layer may be continuous toward the outside, or the resist layer may be inclined toward the outside (form a slope).

[0032] Furthermore, the configuration around the component mounting land 20b shown on the right in Figure 1A is the same as the configuration of the component mounting land 20a shown on the left, except that it is a left-right reversal.

[0033] In the module of the present invention, when viewed from above, a plurality of component mounting lands are provided vertically and / or horizontally for a single electronic component, and it is preferable that the thinnest part of the resist extends from the space below the electronic component between opposing component mounting lands to the area outside the electronic component. This feature will be explained with reference to Figures 1B and 1C.

[0034] Figure 1B is a top view of the module, and Figure 1A is also a cross-sectional view along line A-A in Figure 1B. In Figure 1B and each top view in this specification, the same hatching is applied to the same parts as in Figure 1A and the corresponding cross-sectional views in each figure. Overlapping elements in the top view are shown with transparent hatching. The resist layer 31a in the land proximity region 21a and the resist layer 32a in the outer region 22a are shown with the same hatching in Figure 1A, but with different hatching (the design is the same, but the line density is different) in the top view. In addition, the thinnest resist portion 40 and the extended portions 41a and 41b are shown as white areas without hatching. Figure 1C is a top view of Figure 1B with the electronic components removed and the positions of the thinnest resist portion and extended portions connected. In Figure 1C, the thinnest resist portion 40 located in the space below the electronic components is enclosed by a dashed line. As a result, a dashed line is shown at the boundary between the thinnest part of the resist 40 and the extended parts (41a, 41b), but in reality, the thinnest part of the resist 40 and the extended parts (41a, 41b) are continuous and there is no boundary.

[0035] Figures 1B and 1C show that multiple (two) component mounting lands 20a and 20b are provided laterally for a single electronic component 100. The thinnest part of the resist 40 extends to the areas outside (above and below) the space below the electronic component 50. The area extended above the space below the electronic component 50 is the upper extension 41a of the thinnest part of the resist, and the area extended below is the lower extension 41b of the thinnest part of the resist.

[0036] If the thinnest part of the resist extends from the space below the electronic component between opposing component mounting lands to the area outside the electronic component, the sealing resin can be injected into the space below the electronic component from this extended portion, thereby enabling better sealing of the electronic component with the sealing resin.

[0037] Furthermore, it is preferable that the width of the expansion portion (shown by double arrows W1a and W1b in Figure 1B) is greater than the maximum diameter of the resin filler contained in the encapsulating resin to be injected. It is even more preferable that the width is 5 μm or more greater than the maximum diameter of the resin filler contained in the encapsulating resin. For example, if the maximum diameter of the resin filler is 25 μm, it is preferable that the width of the expansion portion exceeds 25 μm, and more preferably exceeds 30 μm. If the maximum diameter of the resin filler is 10 μm, it is preferable that the width of the expansion portion exceeds 10 μm, and more preferably exceeds 15 μm. When the relationship between the width of the expansion portion and the maximum diameter of the resin filler is as described above, the injection of the encapsulating resin into the space below the electronic component can be performed even more effectively.

[0038] In the module of the present invention, the outer periphery shape of the region where the thickness of the resist layer is the same as the thickness of the resist layer in the land proximity region, when viewed from above, may be substantially similar to the outer periphery shape of the electronic component. This feature will be explained with reference to Figure 1B.

[0039] In Figures 1B and 1C, the region where the thickness of the resist layer is the same as the thickness of the resist layer 31a in the land proximity region 21a is shown with the same hatching as the resist layer 31a. The outer perimeter shape of that region is rectangular. In Figure 1B, the outer perimeter shape of the electronic component 100 is rectangular. Although it is not strictly rectangular when considering the thickness of the external electrode 110, the shape can be defined as rectangular without considering the thickness of the external electrode 110. That is, the outer perimeter shape of the region where the thickness of the resist layer is the same as the thickness of the resist layer 31a in the land proximity region 21a and the outer perimeter shape of the electronic component 100 are both rectangular and similar in shape. The inner perimeter shape of the region where the thickness of the resist layer is the same as the thickness of the resist layer in the land proximity region is not relevant. In Figure 1B, the inner perimeter shape is not rectangular.

[0040] The module of the present invention is used by encapsulating the periphery of electronic components with an encapsulating resin. FIG. 1D is a cross-sectional view schematically showing an example in which the periphery of the electronic components of the module shown in FIG. 1A is encapsulated with an encapsulating resin. The encapsulating resin 70 covers the upper surface and the side surfaces of the electronic component 100, contacts the bottom surface 106 of the electronic component 100, and is injected into the lower space 50 of the electronic component. By injecting the encapsulating resin 70 into the lower space 50 of the electronic component, the position of the electronic component 100 is fixed and stabilized within the module. Further, contact of moisture, air, etc. with electrical elements such as the electronic component 100, solder 60, and component mounting land 20 from the outside is prevented.

[0041] The case where the thinnest resist portion in the lower space of the electronic component is a portion where the thickness of the resist layer is thinner than the thickness of the resist layer outside the component mounting land will be described.

[0042] FIG. 2 is a cross-sectional view schematically showing an example of a module in which the thinnest resist portion is a portion where the thickness of the resist layer is thinner than the thickness of the resist layer outside the component mounting land. In the module 2 shown in FIG. 2, a resist layer 33 is provided on the surface 16 of the substrate in the lower space 50 of the electronic component. The thickness of the resist layer 33 (indicated by the double-headed arrow t in FIG. 2) is thinner than the thickness of the resist layer in the region outside the component mounting land, that is, the land adjacent region 21a (indicated by the double-headed arrow t in FIG. 2). ４ shown) is thinner than the thickness of the resist layer in the region outside the component mounting land, that is, the land adjacent region 21a (indicated by the double-headed arrow t ２ shown) of the resist layer.

[0043] As described above, the lower space of the electronic component is a portion where the encapsulating resin is injected. Even when a resist layer is provided on the surface of the substrate in this portion, if the thickness of the resist layer is thin, the encapsulating resin can be sufficiently injected into the lower space of the electronic component from the thinnest resist portion. By doing so, it is possible to obtain a module that can perform good encapsulation with the encapsulating resin while having a resist layer for preventing solder short circuits. In the examples of the modules shown hereinafter, similar to FIG. 1A, the thinnest resist portion will be described as a portion where no resist layer exists on the surface of the substrate.

[0044] In the module of the present invention, in a top view, the outer peripheral shape of a region where the thickness of the resist layer is the same as that of the resist layer in the land-proximate region may be substantially similar to a shape that combines the outer peripheral shape of a region where the thickness of the surface layer of the substrate including the spatial area under the electronic component is same as that of the resist layer and the outer peripheral shape of the electronic component. This feature will be described with reference to FIG. 3. FIG. 3 is a top view schematically showing an example of the module. The basic configuration is the same as that of FIG. 1B.

[0045] In the module 3 shown in FIG. 3, the region where the thickness of the resist layer is the same as that of the resist layer 31a in the land-proximate region 21a is indicated by the same hatching as that of the resist layer 31a. The outer peripheral shape of that region is cross-shaped. This outer peripheral shape is indicated by a dashed line 3A. Also, the combined shape of the outer peripheral shape of the region where the thickness of the surface layer of the substrate including the spatial area under the electronic component is the same as that of the resist layer and the outer peripheral shape of the electronic component is also cross-shaped. This shape is indicated by a dashed line 3B. The dashed line 3B is located inside the dashed line 3A. Note that the region where the thickness of the surface layer of the substrate including the spatial area under the electronic component is the same as that of the resist layer is the thinnest resist region where no resist layer is provided.

[0046] In the case of this form, it can also be said that the inner cross shape is a shape in which the outer peripheral shape of the electronic component (shape not considering the thickness of the external electrode) is combined on both lateral sides with respect to the shape of the thinnest resist region. And it can be said that the region where the thickness of the resist layer becomes slightly thinner in the land-proximate region has a shape enlarged by a certain distance based on the combined region of the thinnest resist region and the outer peripheral shape of the electronic component (shape not considering the thickness of the external electrode). In this form, since the region where the resist layer becomes slightly thinner (resist layer 31a) is smaller than that in the form of FIG. 1A, it is considered that the effect of preventing solder short circuit with adjacent components (not shown) is improved compared to the form of FIG. 1A.

[0047] In the module of the present invention, multiple electronic components are mounted on the surface of a substrate, and the spaces beneath different electronic components may be connected by connecting portions where the thickness of the resist layer is the same as the thickness of the resist layer at the thinnest part of the resist in each electronic component's space beneath the component. This feature will be explained with reference to Figures 4A and 4B. Figure 4A is a schematic cross-sectional view showing an example of the module. Figure 4B is a top view of the module, and Figure 4A is also a cross-sectional view taken along line B-B in Figure 4B.

[0048] In module 4 shown in Figure 4A, the shape of the external electrode 111 of electronic component 101 differs from that of the external electrode 110 of electronic component 100 shown in Figure 1A. While the external electrode 111 of electronic component 101 is a land shape provided on the bottom surface of the electronic component 101, the method of forming the external electrode is not particularly limited. The electronic component 100 shown in Figure 1A can also be used in module 4 shown in Figure 4A. Except for the external electrode of the electronic component, the basic configuration shown in the cross-sectional view of Figure 4A is the same as in Figure 1A.

[0049] As shown in Figure 4B, multiple electronic components are mounted on the surface of the substrate in module 4. In Figure 4B, the electronic component shown at the top is called electronic component 101a, and the electronic component shown at the bottom is called electronic component 101b. For each of electronic components 101a and 101b, the thinnest part 40 of the resist is extended to the area outside (upper and lower) of the space 50 below the electronic component. The area extended upward is the upper extension 41a of the thinnest part of the resist, and the area extended downward is the lower extension 41b of the thinnest part of the resist.

[0050] The lower extension portion 41b of the thinnest resist portion of electronic component 101a and the upper extension portion 41a of the thinnest resist portion of electronic component 101b are connected to form a connecting portion 42. The thickness of the resist layer in the connecting portion 42 is the same as the thickness of the thinnest resist portion, and in the module 4 shown in Figure 4B, there is no resist layer on the substrate surface in the connecting portion 42. With this configuration, even when the gap between electronic components is small, the resin filling performance at the bottom of the electronic components can be improved.

[0051] Furthermore, in module 4 shown in Figure 4B, the thinnest resist portion 40 of each electronic component 101a and 101b is extended to the area outside (upper and lower) of the space 50 below the electronic component. However, the extended portion does not need to be provided on the side opposite to the connecting portion when viewed from the electronic component, i.e., the upper side of electronic component 101a and the lower side of electronic component 101b.

[0052] In the module of the present invention, when viewed from above, multiple component mounting lands are provided vertically and horizontally for a single electronic component, and the thinnest resist portion may be provided on the surface of the substrate in both the space below the electronic component between vertically opposing component mounting lands and the space below the electronic component between horizontally opposing component mounting lands. This feature will be explained with reference to Figures 5A and 5B. Figure 5A is a schematic cross-sectional view showing an example of the module. Figure 5B is a top view of the module, and Figure 5A is also a cross-sectional view taken along line C-C in Figure 5B.

[0053] In the module 5 shown in Figures 5A and 5B, multiple (two) component mounting pads are provided vertically and multiple (three) horizontally for each electronic component 102. The component mounting pads are named 20a, 20c, and 20b from the top left, and 20d, 20f, and 20e from the bottom left.

[0054] The electronic component 102 is provided with a total of six external electrodes corresponding to the positions of the component mounting pads. Figure 5A shows the external electrodes 112a, 112c, and 112b located in the upper positions in Figure 5B.

[0055] As shown in Figure 5B, the vertically opposing component mounting lands are component mounting lands 20a and 20d, component mounting lands 20c and 20f, and component mounting lands 20b and 20e, respectively. The thinnest resist areas 43ad, 43cf, and 43be are provided in the space below the electronic components between the vertically opposing component mounting lands. Each of these thinnest resist areas is a region on the substrate surface where no resist layer exists.

[0056] The component mounting lands facing each other laterally are component mounting lands 20a and 20c, and component mounting lands 20c and 20b in the upper row, and component mounting lands 20d and 20f, and component mounting lands 20f and 20e in the lower row. In the space below the electronic components between the laterally facing component mounting lands, the thinnest resist areas 44ac and 44cb are provided in the upper row, and 44df and 44fe are provided in the lower row. Each thinnest resist area is a part of the substrate surface where there is no resist layer.

[0057] Upper extensions 41ac and 41c are provided at the thinnest resist portions 44ac and 44cb in the upper section, and lower extensions 41df and 41fe are provided at the thinnest resist portions 44df and 44fe in the lower section.

[0058] In this configuration, the sealing resin is easily injected into the space below the electronic component from the thinnest part of the resist located in the space below the electronic component between the laterally facing component mounting lands. In particular, the presence of upper and lower expansion sections allows the sealing resin to be injected into the space below the electronic component from these expansion sections. In other words, even when the gap between component mounting lands is small, the resin filling performance between component mounting lands, which is difficult to fill with resin, can be improved.

[0059] Figure 5B shows an example of a module in which an upper extension and a lower extension are provided as extensions to the thinnest part of the resist. However, a left extension and a right extension may also be provided as extensions to the thinnest part of the resist. This configuration will be explained with reference to Figure 6. Figure 6 is a schematic top view showing another example of the module.

[0060] The configuration of module 6 shown in Figure 6 is similar to the configuration of module 5 shown in Figure 5B. A left extension portion 41ad is provided as an extension of the thinnest resist portion 43ad on the left side, located in the space below the electronic components between vertically opposing component mounting lands. A right extension portion 41be is provided as an extension of the thinnest resist portion 43be on the right side, located in the space below the electronic components between vertically opposing component mounting lands.

[0061] In this configuration, the sealing resin is easily injected into the space below the electronic component from the thinnest part of the resist located in the space below the electronic component between vertically opposing component mounting lands. The presence of left and right expansion sections allows the sealing resin to be injected into the space below the electronic component from these expansion sections.

[0062] Next, a configuration of the module of the present invention in which resist-coated wiring is arranged on the surface of the substrate in the space below the electronic component will be described. In this configuration, resist-coated wiring, which is wiring covered with resist, is arranged on the surface of the substrate in the space below the electronic component. In a top view, multiple component mounting lands are provided for one electronic component, and the thinnest resist portion is provided in the space below the electronic component between the component mounting lands. In addition, in a top view, multiple component mounting lands are provided vertically and / or horizontally for one electronic component, and the thinnest resist portion may extend from the space below the electronic component between opposing component mounting lands to the area outside the electronic component.

[0063] The thinnest part of the resist can be located at any position in the space below the electronic components between the component mounting lands, but it is preferable that the thinnest part of the resist be located between the component mounting lands and the resist-coated wiring. This configuration will be explained with reference to Figures 7A and 7B. Figure 7A is a schematic cross-sectional view showing an example of a module.

[0064] In the module 7 shown in Figure 7A, resist-coated wiring 80 is arranged on the surface 16 of the substrate in the space 50 below the electronic components. Resist-coated wiring 80 is wiring in which the surface of wiring 81 is covered with a resist layer 82.

[0065] The areas between the resist-coated wiring 80 and the component mounting land 20a, and between the resist-coated wiring 80 and the component mounting land 20b, are areas 40 where the resist layer is not provided on the surface 16 of the substrate, making them the thinnest resist areas. In other words, the thinnest resist areas are provided between the component mounting land and the resist-coated wiring. Furthermore, since the location where these thinnest resist areas 40 are provided is also the location between the component mounting land 20a and the component mounting land 20b, it can also be said that the thinnest resist areas are provided in the space below the electronic components between the component mounting lands.

[0066] By providing a thinnest resist layer on the substrate surface, the sealing resin can be injected into the space beneath the electronic components from this thinnest resist layer, even when resist-coated wiring is present. This allows for a module that provides a resist layer to prevent solder shorts while also enabling good sealing with the sealing resin.

[0067] The overall thickness of the resist-coated wiring, the thickness of the wiring constituting the resist-coated wiring, and the thickness of the resist layer constituting the resist-coated wiring are not particularly limited, but from the viewpoint of facilitating the injection of the encapsulating resin into the space beneath the electronic component, it is preferable that the overall thickness of the resist-coated wiring, the thickness of the wiring constituting the resist-coated wiring, and the thickness of the resist layer constituting the resist-coated wiring are all thin.

[0068] It is preferable to perform the process of forming resist-coated wiring on the surface of the substrate simultaneously with the formation of component mounting lands and the formation of a resist layer covering a portion of the component mounting lands, in order to shorten the number of processes. From this viewpoint, the thickness of the resist layer in the resist-coated wiring may be approximately the same as the thickness of the resist layer outside the component mounting lands. Also, the thickness of the wiring in the resist-coated wiring may be approximately the same as the thickness of the component mounting lands.

[0069] Furthermore, the thickness of the resist layer may change outside the component mounting land, and the thickness of the resist layer in the land proximity region adjacent to the component mounting land may be thinner than the thickness of the resist layer in the region outside the land proximity region. This characteristic is the same as the description with reference to Figure 1A, where the thickness of the resist layer 31a in the land proximity region 21a outside the component mounting land 20a is thinner than the thickness of the resist layer 32a in the region 22a outside the land proximity region 21a.

[0070] Figure 7B is a top view of the module, and Figure 7A is a cross-sectional view along line D-D in Figure 7B. In Figure 7B, in a top view, multiple component mounting lands are provided vertically and multiple component mounting lands are provided horizontally for a single electronic component, and the thinnest part of the resist is provided on the surface of the substrate in the space below the electronic component between the horizontally opposing component mounting lands.

[0071] In the module 7 shown in Figure 7B, multiple (two) component mounting pads are provided vertically and horizontally for each electronic component 103. The component mounting pads are named 20a and 20b from the upper left, and 20d and 20e from the lower left.

[0072] The electronic component 103 is provided with a total of four external electrodes corresponding to the positions of the component mounting pads. Figure 7A shows the external electrodes 112a and 112b located in the upper positions in Figure 7B.

[0073] The thinnest part of the resist 40 extends into the external (upper and lower) areas of the space 50 below the electronic component. The area extended upward is the upper extension 41ab of the thinnest part of the resist, and the area extended downward is the lower extension 41de of the thinnest part of the resist. The top view shape of the thinnest part of the resist 40 is rectangular, and the shape shown in Figure 7B can also be described as a shape in which a rectangular upper extension is connected on top of the rectangle of the thinnest part of the resist, and a rectangular lower extension is connected below it.

[0074] The resist-coated wiring is provided in the space below the electronic components between laterally opposing component mounting lands. Specifically, the resist-coated wiring 80 is provided between laterally opposing component mounting lands 20a and 20b in the upper section, and between laterally opposing component mounting lands 20d and 20e in the lower section.

[0075] The resist-coated wiring 80 extends vertically through the module 7, from the upper extension 41ab of the thinnest part of the resist, through the lower electronic component space 50 which is the space between the electronic component 103 and the surface 16 of the substrate, to the lower extension 41de of the thinnest part of the resist. Furthermore, the resist-coated wiring 80 extends vertically beyond the range shown in Figure 7B.

[0076] In module 7 shown in Figure 7B, the thinnest part of the resist extension is provided between multiple (two) component mounting lands (two locations) that are oriented laterally.

[0077] The following describes another example of a module having resist-coated wiring. In the module of the present invention, when viewed from above, multiple component mounting lands are provided vertically and multiple component mounting lands are provided horizontally for a single electronic component, and the thinnest resist portion may be provided in the space below the electronic component between the component mounting lands, in the area where resist-coated wiring does not exist between the component mounting lands. This embodiment will be described with reference to Figure 8. Figure 8 is a schematic top view showing another example of the module.

[0078] The configuration of module 8 shown in Figure 8 is similar to the configuration of module 7 shown in Figure 7B. The top view shape of the thinnest resist portion 40 is cross-shaped, and it has a left thinnest resist portion 43ad and a right thinnest resist portion 43be, which are provided in the space below the electronic components between vertically opposing component mounting lands. A left extension portion 41ad is provided as an extension of the left thinnest resist portion 43ad, and a right extension portion 41be is provided as an extension of the right thinnest resist portion 43be.

[0079] No resist-coated wiring 80 is provided between vertically opposing component mounting lands 20a and 20d, nor is it provided between vertically opposing component mounting lands 20b and 20e. In other words, the thinnest part of the resist is located in the area of ​​the space below the electronic components between the component mounting lands where no resist-coated wiring exists between the component mounting lands.

[0080] In module 8 shown in Figure 8, the thinnest part of the resist is extended in a total of four locations: between multiple (two) component mounting lands in the horizontal direction (two locations) and between multiple (two) component mounting lands in the vertical direction (two locations).

[0081] In this configuration, the thinnest part of the resist is provided in the area between component mounting lands where resist-coated wiring does not exist, allowing the sealing resin to be injected into the space below the electronic component from this thinnest part of the resist. Therefore, even if resist-coated wiring is present, good sealing with the sealing resin can be achieved.

[0082] In the module of the present invention, when viewed from above, multiple component mounting lands are provided vertically and horizontally for a single electronic component, and resist-coated wiring is provided between horizontally opposing component mounting lands, bends in the space below the electronic component, and may also be provided continuously between vertically opposing component mounting lands. This embodiment will be described with reference to Figure 9. Figure 9 is a schematic top view showing another example of the module.

[0083] The configuration of module 9 shown in Figure 9 is similar to that of module 8 shown in Figure 8, and the shape of the thinnest part of the resist and the extended part are the same.

[0084] Module 9 is provided with resist-coated wiring 83. The resist-coated wiring 83 is provided between component mounting lands 20d and 20e that are facing each other horizontally, extends from bottom to top, bends 90 degrees to the right at the bend 84 in the space below the electronic component, and the resist-coated wiring 83 is also continuously provided between component mounting lands 20b and 20e that are facing each other vertically.

[0085] In this configuration, the thinnest part of the resist exists around the resist-coated wiring, allowing the sealing resin to be injected into the space below the electronic component from this thinnest part of the resist around the resist-coated wiring. Furthermore, since the thinnest part of the resist is also provided in areas where resist-coated wiring does not exist between component mounting lands, the sealing resin can be injected into the space below the electronic component from this thinnest part of the resist. Therefore, even in the presence of resist-coated wiring, good sealing with the sealing resin can be achieved.

[0086] In the module of the present invention, in a top view, there are first and second lands which serve as multiple component mounting lands, and resist-coated wiring is provided between the opposing first and second lands, and the width of the thinnest part of the resist may differ on the first land side and the second land side with respect to the resist-coated wiring. Furthermore, multiple electronic components are mounted on the surface of the substrate, and the thickness of the resist layer of the resist-coated wiring may be greater in the portion that extends from the space below the electronic components to the region between the multiple electronic components than the thickness of the resist layer in the space below the electronic components. This embodiment will be explained with reference to Figure 10. Figure 10 is a schematic top view showing another example of the module.

[0087] In the module 10 shown in Figure 10, three electronic components (electronic components 101a, 101b, and 101c) are mounted. Electronic component 101a is in the upper row, electronic component 101b is on the left side of the lower row, and electronic component 101c is on the right side of the lower row.

[0088] A first land 20g on the left and a second land 20h on the right are provided as component mounting lands on which the electronic component 101a is mounted. A resist-coated wiring 85 is provided between the opposing first land 20g and second land 20h, and bends 90 degrees to the right at a bend 86 below the electronic component 101a, extending into the area between the electronic component 101a and the electronic component 101c.

[0089] The resist layers constituting the resist-coated wiring 85 have different widths: the resist layer 82g on the first land 20g side (indicated by the double-headed arrow g) and the resist layer 82h on the second land 20h side (indicated by the double-headed arrow h). The width of resist layer 82g is greater than the width of resist layer 82h. The resist-coated wiring 85 is located exactly in the center between the opposing first land 20g and second land 20h. Therefore, due to the difference in the width of the resist layers, the area of ​​the thinnest resist portion 45g located between the first land 20g and the resist-coated wiring 85 is different from the area of ​​the thinnest resist portion 45h located between the second land 20h and the resist-coated wiring 85. The thinnest resist portion 45h is wider than the thinnest resist portion 45g.

[0090] Furthermore, the method for making the width of the thinnest resist portion between the first land and the resist-coated wiring different from the width of the thinnest resist portion between the second land and the resist-coated wiring is not limited to making the width of the resist layer constituting the resist-coated wiring different. The position of the resist-coated wiring may also be offset from the center of the first and second lands, so that it is closer to either the first or the second land.

[0091] The resist-coated wiring 85 bends 90 degrees to the right at the bending portion 86 and extends into the region between electronic component 101a and electronic component 101c. The thickness of the resist layer (resist layer 82h, resist layer 82g) of the resist-coated wiring 85 in the space 50 below the electronic component is the same as the thickness of the resist layer 31a in the land proximity region 21a.

[0092] In the portion of the resist-coated wiring 85 that extends to the area between electronic component 101a and electronic component 101c, the resist layer 82ac of the resist-coated wiring 85 is integrated with the resist layer 32a in the area 22a outside the land proximity area 21a. The thickness of the resist layer in the extended portion is thicker than the thickness of the resist layer (resist layer 82h, resist layer 82g) of the resist-coated wiring 85 in the space 50 below the electronic component. This configuration allows for a narrow gap arrangement between electronic components and enables the routing of surface wiring between electronic components in a narrow gap arrangement. Furthermore, it is possible to place new electronic components in the direction of the area to the right of the resist layer 82ac, for example, which is not shown in the figure.

[0093] In the module of the present invention, there is an electronic component underspace between component mounting lands, which includes a first space between component mounting lands where resist-coated wiring exists, a second space between component mounting lands which does not constitute the first space between component mounting lands and does not have resist-coated wiring, and the thinnest part of the resist may be provided in the second space between component mounting lands. This embodiment will be explained with reference to Figure 11. Figure 11 is a schematic top view showing another example of the module.

[0094] In the module 11 shown in Figure 11, multiple (two) component mounting pads are provided vertically and multiple (five) horizontally for each electronic component 102. The component mounting pads are named 20i, 20j, 20k, 20l, and 20m from the top left, and 20n, 20o, 20p, 20q, and 20r from the bottom left.

[0095] The resist-coated wiring 80 is provided between component mounting lands 20j and 20k in the upper section, and between component mounting lands 20o and 20p in the lower section. The space below the electronic components between component mounting lands 20j and 20k, and between component mounting lands 20o and 20p, are the first space between component mounting lands 51jk and the first space between component mounting lands 51op, respectively.

[0096] The second set of component mounting lands is the space under the electronic components between the component mounting lands 20j, 20k, 20o, or 20p that constitute the first set of component mounting lands, and other component mounting lands, where resist-coated wiring does not exist. Specifically, the spaces under the electronic components between component mounting lands 20i and 20j, between component mounting lands 20k and 20l, between component mounting lands 20n and 20o, and between component mounting lands 20p and 20q are the second set of component mounting lands 52ij, 52kl, 52no, and 52pq, respectively.

[0097] In the first component mounting lands 51jk and 51op, where resist-coated wiring 80 is provided, the resist layer is thick, and there are no areas with the thinnest resist layer. On the other hand, in the second component mounting lands 52ij, 52kl, 52no and 52pq, where resist-coated wiring is not provided, there is no resist layer, and these areas have the thinnest resist layer.

[0098] Furthermore, the thinnest part of the resist between the second component mounting lands each has either an upper or lower extended portion.

[0099] In this configuration, it is difficult to inject the sealing resin into the space below the electronic component from between the first component mounting lands surrounding the resist-coated wiring. However, since there is a thinnest part of the resist between the second component mounting lands adjacent to the first component mounting lands, the sealing resin can be injected into the space below the electronic component from the thinnest part of the resist between the second component mounting lands.

[0100] 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11 Module 15 Substrate 16 Surface of the substrate 20, 20a, 20b, 20c, 20d, 20e, 20f, 20i, 20j, 20k, 20l, 20m, 20n, 20o, 20p, 20q, 20r Component mounting land 20g First land (component mounting land) 20h Second land (component mounting land) 21a Land proximity region 22a Region outside the land proximity region 30 Resist layer 31a Resist layer in the land proximity region 32a Resist layer in the region outside the land proximity region 33 Resist layer (resist layer that is the thinnest part of the resist) 40 Thinnest resist region 41a, 41ab, 41ac, 41cb Upper extension of the thinnest resist region 41b, 41de, 41df, 41fe Lower extension of the thinnest part of the resist 41ad Left extension of the thinnest part of the resist 41be Left extension of the thinnest part of the resist 42 Connecting part 43ad, 43cf, 43be Thinnest part of the resist in the space below the electronic component between vertically opposing component mounting lands 44ac, 44cb, 44df, 44fe Thinnest part of the resist in the space below the electronic component between horizontally opposing component mounting lands 45g Thinnest part of the resist between the resist-coated wiring and the first land 45h Thinnest part of the resist between the resist-coated wiring and the second land 50 Space below the electronic component 51jk, 51op Between the first component mounting lands 52ij, 52kl, 52no, 52pq Between the second component mounting lands 60 Solder 70 Sealing resin 80, 83, 85 Resist-coated wiring 81 Wiring within the resist-coated wiring 82, 82g, 82h Resist layer on the surface of the resist-coated wiring 82ac Resist layer on the surface of the resist-coated wiring in the region extended between two electronic components 84, 86 Bent portion 100, 101, 101a, 101b, 101c, 102, 103 Electronic component 106 Bottom surface of electronic component 110, 111, 112a, 112b, 112c External electrode

Claims

1. A module comprising a substrate having component mounting lands and a resist layer on its surface, and an electronic component mounted on the component mounting lands, wherein in the space below the electronic component, which is the space between the bottom surface of the electronic component and the surface of the substrate, there is a resist thinning area where the resist layer is absent from the surface of the substrate, or where the thickness of the resist layer is thinner than the thickness of the resist layer outside the component mounting lands.

2. The module according to claim 1, wherein the thickness of the resist layer changes outside the component mounting land, and the thickness of the resist layer in the land proximity region in contact with the component mounting land is thinner than the thickness of the resist layer in the region outside the land proximity region.

3. The module according to claim 1 or 2, wherein, in a top view, the outer periphery shape of the region where the thickness of the resist layer is the same as the thickness of the resist layer in the land proximity region is substantially similar to the outer periphery shape of the electronic component.

4. The module according to claim 1 or 2, wherein, in a top view, the outer periphery shape of the region where the thickness of the resist layer is the same as the thickness of the resist layer in the land proximity region is substantially similar to the combined shape of the outer periphery shape of the region where the thickness of the resist layer is the same as the surface of the substrate including the space below the electronic component, and the outer periphery shape of the electronic component.

5. The module according to any one of claims 1 to 4, wherein a plurality of the electronic components are mounted on the surface of the substrate, and the spaces below different electronic components are connected by connecting portions in which the thickness of the resist layer is the same as the thickness of the resist layer at the thinnest part of the resist in each space below the electronic component.

6. The module according to any one of claims 1 to 5, wherein, in a top view, a plurality of component mounting lands are provided vertically and horizontally for one electronic component, and the thinnest portion of the resist is provided on the surface of the substrate in both the space below the electronic component between vertically opposing component mounting lands and the space below the electronic component between horizontally opposing component mounting lands.

7. The module according to any one of claims 1 to 6, wherein, in a top view, a plurality of component mounting lands are provided vertically and / or horizontally for one electronic component, and the thinnest portion of the resist extends from the space below the electronic component between opposing component mounting lands to an area outside the electronic component.

8. A module comprising a substrate having component mounting lands and a resist layer on its surface, and an electronic component mounted on the component mounting lands, wherein in the electronic component lower space, which is the space between the bottom surface of the electronic component and the surface of the substrate, resist-coated wiring, which is wiring covered with resist, is arranged on the surface of the substrate, and in a top view, a plurality of component mounting lands are provided for one electronic component, and in the electronic component lower space between the component mounting lands, there is a resist thinning area on the surface of the substrate where the resist layer is absent, or where the thickness of the resist layer is thinner than the thickness of the resist layer outside the component mounting lands.

9. The module according to claim 8, wherein the thinnest portion of the resist is provided between the component mounting land and the resist-coated wiring.

10. The module according to claim 8 or 9, wherein the thickness of the resist layer in the resist-coated wiring is substantially the same as the thickness of the resist layer outside the component mounting land.

11. The module according to any one of claims 8 to 10, wherein the thickness of the resist layer changes outside the component mounting land, and the thickness of the resist layer in the land proximity region in contact with the component mounting land is thinner than the thickness of the resist layer in the region outside the land proximity region.

12. The module according to any one of claims 8 to 11, wherein, in a top view, a plurality of component mounting lands are provided vertically and a plurality of component mounting lands for one electronic component, and the thinnest portion of the resist is provided in the space below the electronic component between the component mounting lands, in a region where the resist-coated wiring does not exist between the component mounting lands.

13. The module according to any one of claims 8 to 12, wherein, in a top view, a plurality of component mounting lands are provided vertically and horizontally for one electronic component, and the resist-coated wiring is provided between the horizontally opposing component mounting lands, bends in the space below the electronic component, and is also provided continuously between the vertically opposing component mounting lands.

14. The module according to any one of claims 8 to 13, wherein, in a top view, a plurality of first lands and second lands are provided as component mounting lands, the resist-coated wiring is provided between the opposing first lands and the second lands, and the width of the thinnest portion of the resist differs on the first land side and the second land side with respect to the resist-coated wiring.

15. The module according to any one of claims 8 to 14, wherein a plurality of the electronic components are mounted on the surface of the substrate, and with respect to the thickness of the resist layer of the resist-coated wiring, in the portion extended from the space below the electronic components to the region between the plurality of electronic components, the thickness of the resist layer is greater than the thickness of the resist layer in the space below the electronic components.

16. The module according to any one of claims 8 to 15, wherein the electronic component lower space between the component mounting lands comprises a first space between component mounting lands where the resist-coated wiring exists, a second space between component mounting lands between component mounting lands that constitute the first space between component mounting lands and other component mounting lands that do not constitute the first space between component mounting lands, wherein the resist-coated wiring does not exist, and the thinnest portion of the resist is provided in the second space between component mounting lands.

17. The module according to any one of claims 8 to 16, wherein, in a top view, a plurality of component mounting lands are provided vertically and / or horizontally for one electronic component, and the thinnest portion of the resist extends from the space below the electronic component between opposing component mounting lands to an area outside the electronic component.

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