Multilayer circuit substrate and electronic component mounting multilayer substrate
By introducing a heat dissipation layer, through-holes in graphite sheets, and a recessed structure in the substrate, the problem of temperature reduction for both active and passive components is solved, achieving a more efficient heat dissipation effect.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- MURATA MFG CO LTD
- Filing Date
- 2021-06-07
- Publication Date
- 2026-05-12
AI Technical Summary
In multilayer circuit boards, with the miniaturization, high integration and high speed of electronic components, the requirements for heat dissipation are high, and existing technologies are difficult to effectively reduce the temperature of active and passive components at the same time.
A heat dissipation layer is introduced into a multilayer circuit board, through holes are set to cover the outer side of the pad pattern of passive components, and a recess is set on the surface of the main body of the substrate. Graphite sheets are combined as heat dissipation materials, and the heat conduction path is optimized through the through holes and recess structure.
It effectively reduces the temperature of both active and passive components, improves heat dissipation efficiency, and ensures the stability and performance of the components.
Smart Images
Figure CN115735419B_ABST
Abstract
Description
Technical Field
[0001] This invention relates to multilayer circuit boards and multilayer boards for mounting electronic components. Background Technology
[0002] In multilayer circuit boards where electronic components are mounted, the miniaturization, high integration, and high speed of electronic components necessitate higher heat dissipation.
[0003] Patent Document 1 discloses a printed wiring board characterized by having a structure in which a rigid substrate is integrally formed on a portion of a flexible substrate on at least one side, and the flexible substrate having a graphite layer. According to Patent Document 1, a lightweight printed wiring board with excellent heat dissipation characteristics that does not require dedicated cooling components can be provided.
[0004] Patent document 1: Japanese Patent Application Publication No. 2008-218618.
[0005] In the case of the printed wiring board described in Patent Document 1, where active and passive components are mounted, the heat generated by the active component, which is a heat-generating component, can be conducted to the entire substrate through the graphite layer and dissipated to the atmosphere or the casing, so the temperature of the active component is not easily raised. However, there is a concern that the temperature of the passive component may increase due to the heat conducted to the substrate, causing changes in the characteristics of the passive component. Summary of the Invention
[0006] The object of this invention is to provide a multilayer circuit board that, when active and passive components are mounted, prevents both the temperature of the active and passive components from rising excessively. Furthermore, the object of this invention is to provide an electronic component mounting multilayer board on which active and passive components are mounted.
[0007] The multilayer circuit board of the present invention includes: a substrate body comprising a plurality of stacked insulating layers; a first pad pattern disposed on the substrate body for mounting passive components; a second pad pattern disposed on the substrate body for mounting active components; and a heat dissipation layer disposed between the insulating layers and configured to run along the main surface of the insulating layers. The heat dissipation layer has a hole extending through the stacking direction of the insulating layers. When viewed from the stacking direction, the outer edge of the hole in the heat dissipation layer is located outward compared to the first pad pattern, or at a position overlapping with the first pad pattern.
[0008] The electronic component mounting multilayer substrate of the present invention comprises: a substrate body including a plurality of stacked insulating layers; passive components and active components mounted on the substrate body; a first pad pattern disposed on the substrate body for mounting the passive components and connected to the passive components; a second pad pattern disposed on the substrate body for mounting the active components and connected to the active components; and a heat dissipation layer disposed between the insulating layers and configured along the main surface of the insulating layers. The heat dissipation layer has a hole extending through the stacking direction of the insulating layers. When viewed from the stacking direction, the outer edge of the hole in the heat dissipation layer is located outside the first pad pattern or at a position overlapping the first pad pattern.
[0009] According to the present invention, a multilayer circuit board can be provided that, when active components and passive components are installed, not only prevents the temperature of the active components from rising, but also prevents the temperature of the passive components from rising. Attached Figure Description
[0010] Figure 1 This is a cross-sectional view schematically illustrating an example of a multilayer circuit board and an electronic component mounting multilayer board according to the present invention.
[0011] Figure 2 This is a top view illustrating an example of the relationship between the location of the holes in the heat dissipation layer and the shape of the first pad pattern.
[0012] Figure 3 This is another example of a top view schematically illustrating the relationship between the location of the holes in the heat dissipation layer and the shape of the first pad pattern.
[0013] Figure 4 This is another example of a top view schematically illustrating the relationship between the location of the holes in the heat dissipation layer and the shape of the first pad pattern.
[0014] Figure 5 This is a schematic cross-sectional view of the laminate in Embodiment 1-1.
[0015] Figure 6 This is a three-dimensional diagram illustrating a method for measuring the temperature of a laminate.
[0016] Figure 7 It means Figure 6 The graph shows the temperature distribution of the portion indicated by the dashed line. Detailed Implementation
[0017] The following describes the multilayer circuit board and the multilayer board for mounting electronic components according to the present invention.
[0018] However, the present invention is not limited to the following structures, and can be appropriately modified and applied without changing the spirit of the invention. Furthermore, structures combining two or more of the preferred structures described below are also part of the present invention.
[0019] Figure 1 This is a cross-sectional view schematically illustrating an example of a multilayer circuit board and an electronic component mounting multilayer board according to the present invention.
[0020] Figure 1 The electronic component mounting multilayer substrate 100 shown includes a multilayer circuit board 1 and a passive component PC and an active component AC mounted on the multilayer circuit board 1.
[0021] Passive components (PC) can include, for example, chip-shaped components such as resistors, capacitors, or inductors, oscillators, and filters. Active components (AC) can include, for example, semiconductor elements such as transistors, diodes, ICs, or LSIs.
[0022] The multilayer circuit board 1 includes a substrate body 10, a first pad pattern 20 for mounting passive components PC, a second pad pattern 30 for mounting active components AC, and a heat dissipation layer 40. The multilayer circuit board 1 also includes a conductor layer 51 serving as a wiring conductor 50 and wiring vias 52. Preferably, the multilayer circuit board 1 also includes thermal vias 60. The multilayer circuit board 1 may also include a protective layer 70.
[0023] The substrate body 10 is a laminate comprising a plurality of insulating layers 11. The substrate body 10 has a first surface S1 and a second surface S2 opposing each other in the lamination direction of the insulating layers 11. Figure 1 The diagram shows the boundaries of adjacent insulating layers 11 in the stacking direction. However, in reality, there are cases where the boundaries of insulating layers 11 cannot be visually confirmed.
[0024] The insulating layer 11 is, for example, a dielectric layer. The insulating layer 11 may also be flexible.
[0025] The insulating layer 11 is made of a resin material, for example. Examples of resin materials constituting the insulating layer 11 include liquid crystal polymer (LCP), polyetheretherketone (PEEK), polyetherimide (PEI), polyphenylene sulfide (PPS), and polyimide (PI). Preferably, the insulating layer 11 is a resin layer made of a thermoplastic resin such as LCP. By forming the insulating layer 11 using a resin sheet made of a thermoplastic resin, the substrate body 10 can be easily formed.
[0026] Alternatively, the insulating layer 11 may also be made of a ceramic material. Examples of ceramic materials constituting the insulating layer 11 include low-temperature sintered ceramics (LTCC). LTCC materials are ceramic materials that can be sintered at a firing temperature of 1000°C or below and can be co-fired with copper or silver.
[0027] A first pad pattern 20 is provided on the substrate body 10 for mounting passive components (PC). Figure 1 In the example shown, the passive component PC is mounted on the surface of the substrate body 10, specifically on the first surface S1 of the substrate body 10. In this case, the first pad pattern 20 is provided on the first surface S1 of the substrate body 10. Alternatively, the passive component PC can be embedded inside the substrate body 10. In this case, the first pad pattern 20 is provided inside the substrate body 10.
[0028] A second pad pattern 30 is provided on the substrate body 10 for mounting the active component AC. Figure 1 In the example shown, the active component AC is mounted on the surface of the substrate body 10, specifically on the first surface S1 of the substrate body 10. In this case, the second pad pattern 30 is provided on the first surface S1 of the substrate body 10. Alternatively, if the passive component PC and the active component AC are mounted on the surface of the substrate body 10, the passive component PC can be mounted on the first surface S1 of the substrate body 10, and the active component AC can be mounted on the second surface S2 of the substrate body 10. In this case, the second pad pattern 30 is provided on the second surface S2 of the substrate body 10. The active component AC can also be internally mounted within the substrate body 10. In this case, the second pad pattern 30 is provided inside the substrate body 10.
[0029] A heat dissipation layer 40 is disposed inside the substrate body 10. Specifically, the heat dissipation layer 40 is disposed between the insulating layers 11 and is configured to run along the main surface of the insulating layers 11.
[0030] The surface of the heat dissipation layer 40 can also be covered with a conductor such as copper.
[0031] Materials constituting the heat dissipation layer 40 include, for example, graphite sheets and carbon nanotube sheets. Preferably, the heat dissipation layer 40 is a graphite sheet. A graphite sheet is a sheet material formed by processing graphite into a sheet shape. Graphite sheets have higher thermal conductivity in the planar direction than in the thickness direction, and are inexpensive materials, making them a suitable material for the heat dissipation layer 40.
[0032] The heat dissipation layer 40 has a hole 40a that extends through the insulation layer 11 in the stacking direction. When viewed from the stacking direction, the outer edge of the hole 40a of the heat dissipation layer 40 is located outside the first pad pattern 20, or at a position that overlaps with the first pad pattern 20.
[0033] The heat generated by the active component AC, which is a heat-generating component, is mainly conducted through the heat dissipation layer 40 and dissipated to the atmosphere or the housing. By providing holes 40a of the heat dissipation layer 40 directly below the first pad pattern 20, the heat dissipation layer 40 directly below the passive component PC is removed, which can suppress heat conduction to the passive component PC. As a result, not only is it difficult for the temperature of the active component AC to rise, but it is also difficult for the temperature of the passive component PC to rise.
[0034] The shape of the holes 40a in the heat dissipation layer 40 when viewed from the stacking direction is not particularly limited, for example, polygons such as quadrilaterals, circles, ellipses, etc. can be listed.
[0035] The position of the mounting holes 40a in the heat dissipation layer 40 is determined according to the shape of the first pad pattern 20. The shape of the first pad pattern 20 varies depending on the external shape of the passive component PC, the length, width, position, number, etc. of the terminals.
[0036] Figure 2 This is a top view illustrating an example of the relationship between the location of the holes in the heat dissipation layer and the shape of the first pad pattern.
[0037] exist Figure 2 In this configuration, the first pad pattern 20A includes two pads L1 and L2, forming a passive component capable of mounting two terminals. When the outer edge of the hole in the heat dissipation layer is at position X1, and is located outside of the pads L1 and L2, it can be said that the outer edge X1 of the hole in the heat dissipation layer is located outside of the first pad pattern 20A. Conversely, when the outer edge of the hole in the heat dissipation layer is at position X2, and overlaps with the pads L1 and L2, it can be said that the outer edge X2 of the hole in the heat dissipation layer is at a position overlapping with the first pad pattern 20A.
[0038] Figure 3 This is another example of a top view schematically illustrating the relationship between the location of the holes in the heat dissipation layer and the shape of the first pad pattern.
[0039] exist Figure 3 In the first pad pattern 20B, four pads L1, L2, L3, and L4 are provided, forming a passive component capable of mounting four terminals. When the outer edge of the hole in the heat dissipation layer is at position X1, and is located outward compared to all pads L1, L2, L3, and L4, it can be said that the outer edge X1 of the hole in the heat dissipation layer is outward compared to the first pad pattern 20B. On the other hand, when the outer edge of the hole in the heat dissipation layer is at position X2, and overlaps with all pads L1, L2, L3, and L4, it can be said that the outer edge X2 of the hole in the heat dissipation layer is at an overlapping position with the first pad pattern 20B.
[0040] Figure 4 This is another example of a top view schematically illustrating the relationship between the location of the holes in the heat dissipation layer and the shape of the first pad pattern.
[0041] exist Figure 4 In the first pad pattern 20C, nine pads L1, L2, L3, L4, L5, L6, L7, L8, and L9 are provided, forming a passive component capable of mounting nine terminals. When the outer edge of the hole in the heat dissipation layer is at position X1, and is located on the outer side compared to all the pads L1, L2, L3, L4, L6, L7, L8, and L9 located on the outer periphery, it can be said that the outer edge X1 of the hole in the heat dissipation layer is located on the outer side compared to the first pad pattern 20C. On the other hand, when the outer edge of the hole in the heat dissipation layer is at position X2, and overlaps with all the pads L1, L2, L3, L4, L6, L7, L8, and L9 located on the outer periphery, it can be said that the outer edge X2 of the hole in the heat dissipation layer is located at a position overlapping with the first pad pattern 20C.
[0042] In this specification, the number of pads provided with the first pad pattern 20 is irrelevant, but as... Figure 2 , Figure 3 as well as Figure 4 As shown, when the outer edge of the hole 40a of the heat dissipation layer 40 is located outside compared to all the pads located on the outer periphery, the outer edge of the hole 40a of the heat dissipation layer 40 is referred to as being located outside compared to the first pad pattern 20. On the other hand, when the outer edge of the hole 40a of the heat dissipation layer 40 overlaps with all the pads located on the outer periphery, the outer edge of the hole 40a of the heat dissipation layer 40 is referred to as being at a position overlapping with the first pad pattern 20.
[0043] like Figure 1 As shown, preferably, the substrate body 10 has a recess 10a on the surface opposite to the first pad pattern 20 in the stacking direction, separated by the heat dissipation layer 40. When the substrate body 10 has a recess 10a on its surface, when viewed from above in the stacking direction, the outer edge of the recess 10a of the substrate body 10 is located outside the first pad pattern 20, or at a position overlapping with the first pad pattern 20. Figure 1 In the example shown, the first pad pattern 20 is provided on the first surface S1 of the substrate body 10, so a recess 10a is provided on the second surface S2 of the substrate body 10.
[0044] The material of the insulating layer 11 comprising the substrate body 10 has a certain degree of thermal conductivity. Therefore, by recessing the surface of the substrate body 10 on the side opposite to the first pad pattern 20 across the heat dissipation layer 40, the thermal path from the heat dissipation layer 40 to the surface of the substrate body 10 can be shortened, and the surface area of the substrate body 10 can be increased, thus further promoting heat dissipation to the atmosphere. As a result, the temperature of the active component AC and the passive component PC can be made less prone to rise.
[0045] The shape of the recess 10a of the substrate body 10 when viewed from above in the stacking direction is not particularly limited, and for example, polygons such as quadrilaterals, circles, ellipses, etc. can be listed.
[0046] The position of the recess 10a in the substrate body 10 is determined according to the shape of the first pad pattern 20.
[0047] In this specification, the number of pads in the first pad pattern is irrelevant, but rather... Figure 2 , Figure 3 as well as Figure 4 The same relationship is illustrated. When the outer edge of the recess 10a of the substrate body 10 is located outside compared to all the pads located on the outer periphery, the outer edge of the recess 10a of the substrate body 10 is located outside compared to the first pad pattern 20. On the other hand, when the outer edge of the recess 10a of the substrate body 10 overlaps with all the pads located on the outer periphery, the outer edge of the recess 10a of the substrate body 10 is located at a position overlapping with the first pad pattern 20.
[0048] When viewed from above in the stacking direction, the outer edge of the recess 10a of the substrate body 10 is not required to be at the same position as the outer edge of the hole 40a of the heat dissipation layer 40. Preferably, when viewed from above in the stacking direction, the outer edge of the recess 10a of the substrate body 10 is at the same position as the outer edge of the hole 40a of the heat dissipation layer 40, or is located inside the hole 40a of the heat dissipation layer 40. Furthermore, when viewed from above in the stacking direction, the area of the recess 10a of the substrate body 10 is not required to be the same as the area of the hole 40a of the heat dissipation layer 40. Preferably, when viewed from above in the stacking direction, the area of the recess 10a of the substrate body 10 is the same as the area of the hole 40a of the heat dissipation layer 40, or is smaller than the area of the hole 40a of the heat dissipation layer 40.
[0049] When the heat dissipation layer 40 is a graphite sheet, it is preferable that the graphite sheet is a layered graphene sheet formed by stacking graphene with multiple carbon atoms bonded into a hexagonal network structure using van der Waals forces. More preferably, the graphene sheet has a structure in which the planar direction (XY plane) of the stacked graphene is orthogonal to the thickness direction (Z direction). In this case, the planar thermal conductivity of the graphene sheet can be improved compared to the thermal conductivity in the thickness direction.
[0050] While the thickness of the graphite sheet is not particularly limited, it is preferably 10 μm or more, more preferably 20 μm or more. On the other hand, it is preferable that the thickness of the graphite sheet is 200 μm or less, more preferably 100 μm or less, and even more preferably 80 μm or less.
[0051] In addition, the thickness at any 10 points is measured, and the average of these measurements is used to calculate the thickness of the graphite sheet.
[0052] While the thermal conductivity in the planar direction of the graphite sheet is not particularly limited, it is preferably above 700 W / mk, more preferably above 1000 W / mk, even more preferably above 1500 W / mk, and particularly preferably above 1800 W / mk.
[0053] In addition, the thermal conductivity of the graphite sheet in the planar direction is calculated by the following formula (1).
[0054] A=α×d×Cp···· (1)
[0055] Here, A represents the thermal conductivity of the graphite sheet, α represents the thermal diffusivity of the graphite sheet, d represents the density of the graphite sheet, and Cp represents the specific heat capacity of the graphite sheet.
[0056] The thermal diffusivity of graphite sheets cut into 50 mm × 50 mm shapes was measured using a thermal diffusivity measuring device based on periodic heating radiation thermometry (e.g., the Bethel Thermal Wave Analyzer TA) at an ambient temperature of 25 °C.
[0057] The density of the graphite sheet is calculated by measuring the weight and thickness of a sample cut into 50mm×50mm shapes and dividing the measured weight by the calculated volume (50mm×50mm×thickness).
[0058] The specific heat capacity of graphite sheets was determined using a differential scanning calorimeter (e.g., the DSC Q2000 from TA Instruments) at a heating rate of 10 °C / min from 20 °C to 260 °C.
[0059] While the conductivity of the graphite sheet is not particularly limited, it is preferably 7000 S / cm or higher, more preferably 10000 S / cm or higher, even more preferably 13000 S / cm or higher, and particularly preferably 18000 S / cm or higher. On the other hand, it is preferable that the conductivity of the graphite sheet is 25000 S / cm or lower, more preferably 20000 S / cm or lower.
[0060] Furthermore, for example, the conductivity of graphite sheets can be determined by applying a constant current using a four-probe method, using the Loresta-GP manufactured by Mitsubishi Chemical Analysis Co., Ltd.
[0061] While the density of graphite sheets is not particularly limited, it is preferably around 0.8 g / cm³. 3 More preferably, it is 1.8 g / cm³. 3 That's all. On the other hand, the preferred density of the graphite sheets is 2.2 g / cm³. 3 the following.
[0062] The graphite sheets sold can be, for example, graphite manufactured by Kaneka Corporation, or PGS (registered trademark) manufactured by Panasonic Corporation.
[0063] like Figure 1 As shown, the multilayer circuit board 1 further includes a conductor layer 51 serving as a wiring conductor 50 and wiring vias 52. The conductor layer 51 is disposed on the surface or inside the substrate body 10. Specifically, the conductor layer 51 is disposed along the main surface of the insulating layer 11, on the surface of the insulating layer 11, or disposed between the insulating layers 11. The wiring vias 52 are configured to penetrate at least one insulating layer 11 in the stacking direction.
[0064] The conductor layer 51 is composed, for example, of metal monomers such as copper, silver, aluminum, stainless steel (SUS), nickel, and gold, or of alloys of two or more different metals selected from these metals.
[0065] The wiring via 52 is made of metallic materials such as silver, copper, silver alloys, or copper alloys. A silver alloy is an alloy with silver as the main component, and a copper alloy is an alloy with copper as the main component. Furthermore, the main component of an alloy refers to the component with the highest weight percentage, preferably exceeding 50% by weight.
[0066] like Figure 1 As shown, the multilayer circuit board 1 preferably also includes a thermal via 60. The thermal via 60 is configured to penetrate at least one insulating layer 11 in the stacking direction. When the multilayer circuit board 1 includes the thermal via 60, it is preferable that one end of the thermal via 60 is connected to the second pad pattern 30, and the other end of the thermal via 60 is connected to the heat dissipation layer 40.
[0067] The heat-perforated hole 60 is made of a metallic material such as silver, copper, a silver alloy, or a copper alloy. Preferably, the heat-perforated hole 60 is made of the same metallic material as the wiring via 52. Alternatively, the heat-perforated hole 60 may be made of a ceramic material such as nitride ceramic, oxide ceramic, or a mixture of these ceramics. Examples of nitride ceramics include aluminum nitride (AlN), boron nitride (BN), and silicon nitride (Si3N4). Examples of oxide ceramics include alumina (Al2O3).
[0068] like Figure 1As shown, the multilayer circuit board 1 may further include a protective layer 70. The protective layer 70 is disposed on the surface of the substrate body 10. The protective layer 70 is, for example, a solder resist film, a cover film, etc. The protective layer 70 may be disposed on both the first surface S1 and the second surface S2 of the substrate body 10, or on either one. The protective layer 70 is not a necessary structure, so it may not be disposed on the first surface S1 and the second surface S2 of the substrate body 10.
[0069] The multilayer circuit board of the present invention is manufactured as follows. As an example of the multilayer circuit board of the present invention, a method for manufacturing a resin multilayer board having a resin layer as an insulating layer, i.e., a dielectric layer, will be described.
[0070] First, prepare a resin sheet with a conductor foil. A resin sheet with a conductor foil is a sheet material with a conductor foil attached to one side of a resin layer. The resin layer is, for example, composed of a thermoplastic resin such as LCP. Alternatively, PEEK, PEI, PPS, PI, etc., can be used instead of LCP as the material for the resin layer. The conductor foil is, for example, a copper foil with a thickness of 18 μm. Alternatively, silver, aluminum, stainless steel, nickel, gold, or other metal monomers can be used instead of copper as the material for the conductor foil, or an alloy of two or more different metals selected from these metals. The thickness of the conductor foil only needs to be sufficient for circuit formation, for example, between 3 μm and 40 μm.
[0071] Next, a through-hole is formed by irradiating the resin layer side of the resin sheet with the conductor foil using a carbon dioxide laser. The through-hole penetrates the resin layer but not the conductor foil. Afterward, any contaminants in the through-hole are removed. Alternatively, other types of lasers can be used instead of a carbon dioxide laser to form the through-hole. Furthermore, methods other than laser irradiation can also be used to form the through-hole.
[0072] Next, using methods such as screen printing, a resist pattern corresponding to the desired circuit pattern is printed on the surface of the conductor foil of the resin sheet with conductor foil.
[0073] Subsequently, the resist pattern is used as a mask for etching to remove the portions of the conductor foil not covered by the resist pattern. By removing the resist pattern, a conductor layer with the desired conductor pattern is formed on one surface of the resin layer.
[0074] Next, conductive paste is filled into the through-holes using methods such as screen printing. The conductive paste can be silver-based, but it can also be copper-based, for example, instead of silver. Preferably, the conductive paste contains an appropriate amount of metal powder that forms an alloy layer between itself and the metal material serving as the conductor pattern at the temperature during subsequent hot-pressing of the laminated resin layers (hereinafter referred to as the "hot-pressing temperature"). When the conductive paste contains copper as the main component, it is preferable to also contain at least one of silver and nickel, and at least one of tin, bismuth, and zinc, in addition to the main component. This forms the wiring through-holes. Furthermore, it is preferable to form the heat-sealed through-holes at predetermined locations.
[0075] As needed, the resin layer is stamped in the recessed portion that forms the main body of the substrate. Methods other than stamping can also be used to create holes for forming the recesses. For example, laser processing can also be used to create the holes.
[0076] Prepare graphite sheets separately. Stamp the graphite sheets on the parts directly beneath the passive component where there are no graphite sheets, and on the parts through which wiring passes. Alternatively, the method for creating the holes can be other than stamping. For example, laser processing can also be used.
[0077] A temporary laminate is formed by stacking resin sheets and graphite sheets to form a conductor layer and wiring vias. The temporary laminate is then heated and pressurized to obtain a resin multilayer substrate.
[0078] The multilayer circuit board of the present invention is not limited to the above-described embodiments as long as the outer edge of the holes in the heat dissipation layer is located outside the first pad pattern or overlaps with the first pad pattern when viewed from the stacking direction. Therefore, various applications and modifications can be added to the structure and manufacturing conditions of the multilayer circuit board within the scope of the present invention. Similarly, various applications and modifications can be added to the electronic component mounting multilayer board of the present invention within the scope of the present invention.
[0079] For example, multiple passive components may be mounted on the multilayer circuit board of the present invention. That is, the multilayer circuit board of the present invention may also have multiple first pad patterns for mounting each passive component. For example, when both passive components are mounted on the surface of the substrate body, both passive components may be mounted on the first surface of the substrate body, or one passive component may be mounted on the first surface of the substrate body and the other passive component may be mounted on the second surface of the substrate body.
[0080] When multiple passive components are mounted on the multilayer circuit board of the present invention, for at least one passive component, a hole is provided in the heat dissipation layer according to the position of the first pad pattern for mounting the passive component. Preferably, a recess is provided in the substrate body for the first pad pattern in which the hole is provided in the heat dissipation layer. Furthermore, when two or more passive components are mounted, and a hole is provided in the heat dissipation layer according to the position of the first pad pattern for mounting each passive component, a combination of a first pad pattern with a recess and a first pad pattern without a recess in the substrate body may also be used.
[0081] Multiple active components can also be mounted on the multilayer circuit board of the present invention. That is, the multilayer circuit board of the present invention can also have multiple second pad patterns for mounting each active component. For example, when both active components are mounted on the surface of the substrate body, both active components can be mounted on the first surface of the substrate body, or one active component can be mounted on the first surface of the substrate body and the other active component can be mounted on the second surface of the substrate body.
[0082] In the case where multiple active components are mounted on the multilayer circuit board of the present invention, it is preferable to provide a thermal via for at least one active component, which connects the second pad pattern for mounting the active component to the heat dissipation layer.
[0083] The multilayer circuit board of the present invention can be either a flexible substrate or a rigid substrate.
[0084] Example
[0085] The following describes more specific embodiments of the multilayer circuit board and the multilayer board for mounting electronic components according to the present invention. However, the present invention is not limited to these embodiments.
[0086] (Example 1-1)
[0087] Figure 5 This is a schematic cross-sectional view illustrating the laminate in Embodiment 1-1. In this embodiment, a laminate of a resin multilayer substrate, considered as an example of a multilayer circuit board, is fabricated. Due to concerns about thermal properties, conductor layers, wiring vias, and protective layers are not formed.
[0088] Using the above-described method for fabricating a resin multilayer substrate, a laminate 200 with dimensions of 50mm × 50mm × 0.14mm (of which the graphite sheet has a thickness of 0.04mm) is fabricated. Figure 5In this embodiment, at the location corresponding to the active component AC which serves as a heat-generating component, a 10mm × 10mm ceramic heater is provided via a TIM (Thermal Interface Material) with a thermal conductivity of 2 W / mK and a thickness of 0.2mm. Nine heat-permeable holes 60 with a diameter of 0.15mm are evenly arranged directly below the ceramic heater. At the location in the center of the laminate 200, corresponding to the passive component PC, a 10mm × 10mm hole 40a is formed in the graphite sheet serving as the heat dissipation layer 40, and a 10mm × 10mm recess 10a with a thickness of 0.04mm is provided on the back side of the substrate body 10. That is, in this embodiment, neither an active component nor a passive component is provided.
[0089] Figure 6 This is a three-dimensional diagram illustrating a method for measuring the temperature of a laminate.
[0090] like Figure 6 As shown, a laminate 200 is mounted on top of four insulating blocks (5mm × 5mm, 20mm high) 210, and a thermal imaging camera (not shown) mounted on the upper part of the laminate 200 is used to capture the temperature distribution when the ceramic heater 220 is heated at 8W. Measurements are then taken. Figure 6 The temperature distribution is shown by the dashed line in the image.
[0091] Figure 7 It means Figure 6 The graph shows the temperature distribution of the portion indicated by the dashed line. According to... Figure 7 It can be seen that there are holes in the graphite sheet and a recessed part on the back of the substrate body, which reduces the temperature.
[0092] (Examples 1-2)
[0093] Except for not providing a recess on the back side of the substrate body, the laminate was fabricated in the same manner as in Example 1-1, and the temperature distribution was measured.
[0094] (Comparative Example 1-1)
[0095] Except for not setting holes in the graphite sheet, the laminate was fabricated in the same manner as in Example 1-1, and the temperature distribution was measured.
[0096] (Comparative Examples 1-2)
[0097] Except for not providing a recess on the back of the substrate body and not providing holes in the graphite sheet, the laminate was fabricated in the same manner as in Example 1-1, and the temperature distribution was measured.
[0098] For Examples 1-1, 1-2, Comparative Example 1-1 and Comparative Example 1-2, Table 1 shows the heater temperature and the temperature of the passive component configuration section.
[0099] [Table 1]
[0100]
[0101] Compared to Comparative Examples 1-2, which do not have holes in the graphite sheet and recesses in the substrate body, in Comparative Example 1-1, where recesses are provided in the substrate body, the temperature of the passive component placement area remains unchanged. However, in Examples 1-2, where holes in the graphite sheet are provided, although the heater temperature increases by 5°C, the temperature of the passive component placement area decreases. Furthermore, in Example 1-1, where holes in the graphite sheet and recesses in the substrate body are provided, the temperature of the passive component placement area decreases by 5°C compared to Examples 1-2. Therefore, by providing both holes in the graphite sheet and recesses in the substrate body, the temperature of the passive component placement area can be reduced.
[0102] (Example 2-1)
[0103] Except for changing the size of the holes in the graphite sheet in the configuration section of the passive component and the recesses in the substrate body to 5mm×5mm, the laminate was made in the same manner as in Example 1-1, and the temperature distribution was measured.
[0104] (Example 2-2)
[0105] Except for not providing a recess on the back side of the substrate body, the laminate was fabricated in the same manner as in Example 2-1, and the temperature distribution was measured.
[0106] (Comparative Example 2-1)
[0107] Except for not setting holes in the graphite sheet, the laminate was fabricated in the same manner as in Example 2-1, and the temperature distribution was measured.
[0108] (Comparative Example 2-2)
[0109] Except for not providing a recess on the back of the substrate body and not providing holes in the graphite sheet, the laminate was fabricated in the same manner as in Example 2-1, and the temperature distribution was measured.
[0110] For Examples 2-1, 2-2, Comparative Example 2-1 and Comparative Example 2-2, the heater temperature and the temperature of the passive component configuration section are shown in Table 2.
[0111] [Table 2]
[0112]
[0113] Compared to Comparative Example 2-2, which does not have holes in the graphite sheet and recesses in the substrate body, in Comparative Example 2-1, where recesses are provided in the substrate body, the temperature of the passive component placement area remains unchanged. However, in Example 2-2, where holes in the graphite sheet are provided, although the heater temperature increases by 1°C, the temperature of the passive component placement area decreases. Furthermore, in Example 2-1, where holes in the graphite sheet and recesses in the substrate body are provided, the temperature of the passive component placement area decreases by 9°C compared to Example 2-2. Therefore, by providing both holes in the graphite sheet and recesses in the substrate body, the temperature of the passive component placement area can be reduced to the maximum extent.
[0114] (Example 3-1)
[0115] Except for changing the size of the holes in the graphite sheet in the configuration section of the passive component and the recesses in the substrate body to 3mm×3mm, the laminate was made in the same manner as in Example 1-1, and the temperature distribution was measured.
[0116] (Example 3-2)
[0117] Except for not providing a recess on the back side of the substrate body, the laminate was fabricated in the same manner as in Example 3-1, and the temperature distribution was measured.
[0118] (Comparative Example 3-1)
[0119] Except for not setting holes in the graphite sheet, the laminate was fabricated in the same manner as in Example 3-1, and the temperature distribution was measured.
[0120] (Comparative Example 3-2)
[0121] Except for not providing a recess on the back of the substrate body and not providing holes in the graphite sheet, the laminate was fabricated in the same manner as in Example 3-1, and the temperature distribution was measured.
[0122] For Examples 3-1, 3-2, Comparative Example 3-1 and Comparative Example 3-2, Table 3 shows the heater temperature and the temperature of the passive component configuration section.
[0123] [Table 3]
[0124]
[0125] Compared to Comparative Example 3-2, which did not have holes in the graphite sheet and recesses in the substrate body, in Comparative Example 3-1, where recesses were provided in the substrate body, the temperature of the passive component placement area remained unchanged. However, in Example 3-2, where holes were provided in the graphite sheet, the heater temperature remained unchanged, but the temperature of the passive component placement area decreased. Furthermore, in Example 3-1, where holes in the graphite sheet and recesses in the substrate body were provided, the temperature of the passive component placement area decreased by 8°C compared to Example 3-2. Therefore, by providing both holes in the graphite sheet and recesses in the substrate body, the temperature of the passive component placement area can be significantly reduced.
[0126] (Example 4-1)
[0127] Except for changing the size of the holes in the graphite sheet in the configuration section of the passive component and the recesses in the substrate body to 2mm×2mm, the laminate was made in the same manner as in Example 1-1, and the temperature distribution was measured.
[0128] (Example 4-2)
[0129] Except for not providing a recess on the back side of the substrate body, the laminate was fabricated in the same manner as in Example 4-1, and the temperature distribution was measured.
[0130] (Comparative Example 4-1)
[0131] Except for not setting holes in the graphite sheet, the laminate was fabricated in the same manner as in Example 4-1, and the temperature distribution was measured.
[0132] (Comparative Example 4-2)
[0133] Except for not providing a recess on the back of the substrate body and not providing holes in the graphite sheet, the laminate was fabricated in the same manner as in Example 4-1, and the temperature distribution was measured.
[0134] For Examples 4-1, 4-2, Comparative Examples 4-1 and 4-2, Table 4 shows the heater temperature and the temperature of the passive component configuration section.
[0135] [Table 4]
[0136]
[0137] Compared to Comparative Example 4-2, which does not have holes in the graphite sheet and recesses in the substrate body, in Comparative Example 4-1, where recesses are provided in the substrate body, the temperature of the passive component placement area remains unchanged. However, in Example 4-2, where holes are provided in the graphite sheet, the heater temperature remains unchanged, but the temperature of the passive component placement area decreases. Furthermore, in Example 4-1, where holes in the graphite sheet and recesses in the substrate body are provided, the temperature of the passive component placement area decreases by 5°C compared to Example 4-2. Therefore, by providing both holes in the graphite sheet and recesses in the substrate body, the temperature of the passive component placement area can be reduced.
[0138] (Example 5-1)
[0139] Except for changing the size of the holes in the graphite sheet in the configuration section of the passive component and the recesses in the substrate body to 1mm×1mm, the laminate was made in the same manner as in Example 1-1, and the temperature distribution was measured.
[0140] (Example 5-2)
[0141] Except for not providing a recess on the back side of the substrate body, the laminate was fabricated in the same manner as in Example 5-1, and the temperature distribution was measured.
[0142] (Comparative Example 5-1)
[0143] Except for not setting holes in the graphite sheet, the laminate was fabricated in the same manner as in Example 5-1, and the temperature distribution was measured.
[0144] (Comparative Example 5-2)
[0145] Except for not providing a recess on the back of the substrate body and not providing holes in the graphite sheet, the laminate was fabricated in the same manner as in Example 5-1, and the temperature distribution was measured.
[0146] For Examples 5-1, 5-2, Comparative Examples 5-1 and 5-2, the heater temperature and the temperature of the passive component configuration section are shown in Table 5.
[0147] [Table 5]
[0148]
[0149] Compared to Comparative Example 5-2, which does not have holes in the graphite sheet and recesses in the substrate body, in Comparative Example 5-1, where recesses are provided in the substrate body, the temperature of the passive component placement area remains unchanged. However, in Example 5-2, where holes are provided in the graphite sheet, the heater temperature remains unchanged, and the temperature of the passive component placement area decreases. Furthermore, in Example 5-1, where holes in the graphite sheet and recesses in the substrate body are provided, the temperature of the passive component placement area decreases by 2°C compared to Example 5-2. Therefore, by providing both holes in the graphite sheet and recesses in the substrate body, the temperature of the passive component placement area can be reduced.
[0150] Explanation of reference numerals in the attached figures
[0151] 1…Multilayer circuit board, 10…Substrate body, 10a…Recess of substrate body, 11…Insulating layer, 20, 20A, 20B, 20C…First pad pattern, 30…Second pad pattern, 40…Heat dissipation layer, 40a…Hole of heat dissipation layer, 50…Wire conductor, 51…Conductor layer, 52…Wire through-hole, 60…Heat via, 70…Protective layer, 100…Multilayer board for mounting electronic components, 200…Laminated structure, 210…Heat insulation block, 220…Ceramic heater, AC…Active component, PC…Passive component, S1…First side of substrate body, S2…Second side of substrate body, L1, L2, L3, L4, L5, L6, L7, L8, L9…Pads, X1, X2…Outer edge of hole in heat dissipation layer.
Claims
1. A multilayer circuit board, wherein, have: The substrate body comprises multiple stacked insulating layers; The first pad pattern is provided on the substrate body for mounting passive components; The second pad pattern is provided on the substrate body for mounting active components; as well as A heat dissipation layer is disposed between the aforementioned insulating layers and is configured to run along the main surface of the aforementioned insulating layers. The aforementioned heat dissipation layer has holes that extend through the stacking direction of the aforementioned insulating layers. When viewed from the stacking direction, the holes in the heat dissipation layer are located directly below the passive component, and the outer edge of the holes in the heat dissipation layer is located outside the first pad pattern, or the outer edge of the holes in the heat dissipation layer is located at a position overlapping with the first pad pattern.
2. The multilayer circuit board according to claim 1, wherein, The substrate body has a recess on the surface opposite to the first pad pattern, separated by the heat dissipation layer, in the aforementioned stacking direction. When viewed from the stacking direction, the outer edge of the recess of the substrate body is located on the outside compared to the first pad pattern, or the outer edge of the recess of the substrate body is located at a position overlapping with the first pad pattern.
3. The multilayer circuit board according to claim 1 or 2, wherein, It also includes a heat-permeable hole configured to penetrate the insulating layer in the aforementioned stacking direction. One end of the aforementioned heat-perforated hole is connected to the aforementioned second pad pattern, and the other end of the aforementioned heat-perforated hole is connected to the aforementioned heat dissipation layer.
4. The multilayer circuit board according to claim 1 or 2, wherein, The aforementioned heat dissipation layer is a graphite sheet.
5. The multilayer circuit board according to claim 1 or 2, wherein, The aforementioned insulating layer is a resin layer composed of thermoplastic resin.
6. A multilayer substrate for mounting electronic components, wherein, have: The substrate body comprises multiple stacked insulating layers; Passive components and active components are mounted on the aforementioned substrate body; The first pad pattern is provided on the substrate body for mounting the passive component and is connected to the passive component. The second pad pattern is provided on the substrate body for mounting the aforementioned active component and is connected to the aforementioned active component; and A heat dissipation layer is disposed between the aforementioned insulating layers and is configured to run along the main surface of the aforementioned insulating layers. The aforementioned heat dissipation layer has holes that extend through the stacking direction of the aforementioned insulating layers. When viewed from the stacking direction, the holes in the heat dissipation layer are located directly below the passive component, and the outer edge of the holes in the heat dissipation layer is located outside the first pad pattern, or the outer edge of the holes in the heat dissipation layer is located at a position overlapping with the first pad pattern.
7. The electronic component mounting multilayer substrate according to claim 6, wherein, The substrate body has a recess on the surface opposite to the first pad pattern, separated by the heat dissipation layer, in the aforementioned stacking direction. When viewed from the stacking direction, the outer edge of the recess of the substrate body is located on the outside compared to the first pad pattern, or the outer edge of the recess of the substrate body is located at a position overlapping with the first pad pattern.
8. The electronic component mounting multilayer substrate according to claim 6 or 7, wherein, It also includes a heat-permeable hole configured to penetrate the insulating layer in the aforementioned stacking direction. One end of the aforementioned heat-perforated hole is connected to the aforementioned second pad pattern, and the other end of the aforementioned heat-perforated hole is connected to the aforementioned heat dissipation layer.
9. The electronic component mounting multilayer substrate according to claim 6 or 7, wherein, The aforementioned heat dissipation layer is a graphite sheet.
10. The electronic component mounting multilayer substrate according to claim 6 or 7, wherein, The aforementioned insulating layer is a resin layer composed of thermoplastic resin.