JP4283523B2 - Composite multilayer substrate and module using the same - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a composite multilayer substrate composed of a laminate composed of a plurality of layers in which at least one layer is a metal core layer, and a module using the same.
[0002]
[Prior art]
FIG. 12A is a cross-sectional view of a conventional composite multilayer substrate (see, for example, Patent Document 1). The illustrated composite multilayer substrate 1 is applied to a PGA (Pin Grid Array) package.
[0003]
In FIG. 12A, the composite multilayer substrate 1 has a five-layer structure, one of which is a metal core layer. That is, the insulating resin layer 2, the metal core layer 3, and the insulating resin layers 4 to 6 are sequentially laminated in order from the lowest layer. An opening 7 reaching the metal core layer 3 is formed in the lowermost insulating resin layer 2, and a buffer metal layer 9 in which base portions 8 a of pins 8, 8 inserted into the opening 7 are formed in the metal core layer 3. It is connected to the. Further, via conductors 10 and 11 and wiring patterns 12 and 13 are formed between the upper three insulating resin layers 4 to 6, respectively. Via these via conductors 10 and 11 and the wiring patterns 12 and 13, The flip chip connecting buffer metal layer 15 formed in the opening 14 of the uppermost insulating resin layer 6 and the external electrodes 16 and 16 of the metal core layer 3 are electrically connected, and the external electrodes 16 and 16 are connected. Are electrically connected to the pins 8 and 8 through the buffer metal layer 9.
[0004]
Here, the metal core layer 3 is formed by etching the metal plate with the insulating resin layer 4 pasted on the surface to form the external electrodes 16 and 16 corresponding to the pins 8 and 8, respectively, and then the insulating resin layer on the back surface. It is formed by laminating 3a or applying molten resin with a spin coater or the like. As described above, the composite multilayer substrate 1 is applied to a PGA package, and the PGA package is generally the entire back surface except for the peripheral portion of the IC package (or a portion avoiding the central chip mounting portion). Therefore, the external electrodes 16 and 16 are arranged in the same arrangement as the pins of the PGA package, that is, except for the peripheral portion in the layer of the metal core layer 3. It is arranged.
[0005]
In FIG. 12A, substrate reinforcing portions (hereinafter referred to as “substrate reinforcing bodies”) 17 and 17 are provided at the peripheral edge in the metal core layer 3. The substrate reinforcements 17 and 17 are produced by etching or the like from the same metal plate as the external electrodes 16 and 16, and as the name suggests, to increase the physical strength of the peripheral portion of the composite multilayer substrate 1. belongs to.
[0006]
In FIG. 12A, the substrate reinforcements 17 and 17 are drawn so as to be exposed on the side surfaces of the composite multilayer substrate 1, but this is not the case. As shown in FIG. 12B, the metal core layer 3 is formed by laminating the insulating resin layer 3a on the back surface of the metal plate, or applying molten resin with a spin coater or the like. This is because the insulating resin layer 3a (or molten resin) covers the side surfaces (see the X and Y portions in the figure) of the metal plate (substrate reinforcing bodies 17 and 17).
[0007]
[Patent Document 1]
JP 2000-3980 ([0029], [0053]-[0077], FIG. 24)
[0008]
[Problems to be solved by the invention]
The above-described composite multilayer substrate 1 according to the prior art is intended for application to a PGA package, and electrical connection with the substrate is made only through a large number of pins 8 and 8 protruding from the lower surface of the package. It is. And since these pins 8 and 8 are retrofitted, there existed a problem that the processing cost for that and the member cost of a pin were needed. Further, when the package is downsized, the pin pitch is reduced, and the pitch of the holes for inserting the pins on the board on which the package is to be mounted must also be reduced. However, there is a problem that there is a hole pitch limit due to insulation between adjacent holes and the like, which is disadvantageous for miniaturization due to a pin diameter that is dimensionally added to the hole pitch limit. Furthermore, in the high frequency application, the problem that the inductor component of the pin portion has an adverse effect is expected.
[0009]
As described above, the substrate reinforcements 17 and 17 are only for increasing the physical strength of the peripheral portion of the composite multilayer substrate 1, and are therefore actively used as electrical connection terminals. In addition, as shown in FIG. 12B, when the laminate or the molten resin is applied, the substrate reinforcing bodies 17 and 17 are covered with the laminate material or the molten resin. Therefore, the substrate reinforcing bodies 17 and 17 are only used for the purpose (substrate reinforcement) as the name suggests.
[0010]
Therefore, the object of the present invention is to expose the metal core layer on the side surface of the package so that it can be used as a terminal for electrical connection, so that signal transmission can be performed without using a pin terminal or the like, An object of the present invention is to provide a composite multilayer substrate capable of reducing transfer loss for high frequency applications and a module using the same.
[0011]
[Means for Solving the Problems]
  The composite multilayer substrate according to claim 1 is a flat core member made of a material having good electrical conductivity, good thermal conductivity and high rigidity, a resin layer covering the core member, A composite multi-layer substrate that includes a bottomless hole formed in the core member through the front and back or a bottomed hole that does not penetrate through the front and back, and an electronic component is embedded and mounted in the bottomed hole or the bottomed hole with a resin In the core memberThe portion following the end face excluding the bottomed hole or the bottomed hole forming portion is cut, the cut portion is used as a signal transmission portion, and the end face of the signal transmission portion is exposed to the outside, and the signal transmission is performed. Power supply to the electronic component or signal input or signal output using the unitWith featuresTo do.
  Claim2A composite multilayer substrate according to claim1In the composite multilayer substrate described above, a wiring pattern is provided on a resin layer that covers the core member continuous with an exposed portion of an end surface of the core member.And
  Claim3The module according to claim 1Or claim 2A composite multilayer board according to any one of the above is used.And
  Here, the “material having good electrical conductivity, good thermal conductivity and high rigidity” is not particularly limited as long as it has the above three properties, but typically, A metal (metal) core member is preferable, and copper, 42 alloy, invar and the like are particularly preferable.
[0012]
In addition, “bottomed hole” and “bottomed hole” are both electronic components (an electronic component is an active component such as a semiconductor chip or a transistor, a passive component such as a resistive element, a capacitive element or an inductance element, or other The former is different from the former in terms of “holes without bottom (or through holes)” and the latter in terms of “holes with bottom (or recesses)”. . In addition, the opening shape of the “bottom hole” and “bottom hole” should have an appropriate shape (for example, a shape slightly larger than the outer shape of the electronic component) that can easily mount the target electronic component. That's fine.
[0013]
  In the composite multilayer substrate having these characteristics, by providing an exposed portion on the end surface excluding the front and back surfaces of the core member in which the electronic component is embedded and mounted, it can be used as a terminal for electrical connection. To provide a composite multilayer substrate capable of transmitting a signal without passing through a pin terminal and the like and capable of reducing transfer loss in high frequency applications and a module using the sameit can.
  In addition, by providing a wiring pattern in the resin layer covering the core member that is continuous with the exposed portion of the end surface of the core member, the area of the exposed conductor portion when the exposed portion is used as a terminal for electrical connection Can be expanded to increase the bonding strength. Further, it is possible to ensure that the solder continues up to the exposed portion of the end surface of the core member.
[0014]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
FIG. 1 is a cross-sectional view of a module made by applying the technical idea of the present invention.
In addition, “module (English: module)” generally means “standardized structural unit”. A module is also considered a type of unit or part, but a unit is usually positioned as a replaceable component, and a part is itself positioned as a minimal unit, whereas a module is It is often not assumed, and is often designed and manufactured as having a specific function. However, since it is also true that no strict division is defined, this term (“module”) is defined and used in the present specification as follows. That is, a module includes one or a plurality of semiconductor chips, resistor elements, capacitor elements or other electronic components (collectively referred to as “electronic components”) (a combination of different types of electronic components). ) A device that has been mounted to realize a required electronic circuit function and that can be circulated independently in the market. The ease of replacement after being mounted (mounted) on any electronic device is not particularly considered. A mounting form that can be attached and detached by a pin, a connector, or the like may be used, or a form that is mounted in a substantially fixed state by soldering or the like.
[0015]
The module 40 may function as, for example, a power amplifier module, an antenna switch module, or an RF module that integrates them, which is a component of an RF (high frequency) unit in a mobile phone or a portable information terminal with a wireless communication function. It can be distributed as a product in the market.
[0016]
The module 40 has a desired circuit function (power amplifier module, antenna switch module, or the like) by mounting required electronic components on the surface and inside of the composite multilayer substrate having a structure to which the technical idea of the present invention is applied. An integrated RF module or the like) is realized.
[0017]
The structure of the module 40 is largely divided into, for example, “intermediate layer A”, “upper layer B” stacked on the upper surface of the intermediate layer A, and “lower layer C” stacked on the lower surface of the intermediate layer A. Can be divided.
[0018]
The intermediate layer A has a front-side resin layer 42 and a back-side resin layer 43 on both surfaces of a flat core member 41 made of a material (Cu, 42 alloy, Invar, etc.) having good thermal conductivity and high rigidity, respectively. A plurality of (four in the cross-sectional view) bottomless holes 44 to 47 are formed in the core member 41, and appropriate electronic parts 48 to 51 are embedded in the bottomless holes 44 to 47 with a resin and mounted. It has the structure.
[0019]
For convenience of explanation, the leftmost electronic component 48 is a semiconductor chip having a small height, the second electronic component 49 from the left is a capacitor (the height is about the thickness of the core member 41), and the third from the left. It is assumed that the electronic component 50 is a resistor (height dimension is about the thickness dimension of the core member 41), and the electronic component 51 at the right end is a semiconductor chip having a large height dimension.
[0020]
Electronic components 49 and 50 having a height dimension approximately equal to the thickness dimension of the core member 41 are embedded and mounted in the bottomless holes 45 and 46 corresponding thereto. As described above, the electronic components 49 and 50 are capacitors and resistors, respectively, and are components with relatively little heat generation. Therefore, unless special heat countermeasures are required, the electronic components 49 and 50 are fixed on the back surface. Although it may be performed by the adhesives 52 and 53 filled between the side resin layers 43, when the heat generation of the part is large, the adhesives 52 and 53 having good thermal conductivity are used.
[0021]
In the case of the electronic component 48 having a small height dimension, the height dimension adjusting member 54 having an appropriate height is inserted to adjust the height dimension, and when the heat generation of the electronic component 48 is large, A material having good thermal conductivity is used as the material of the height dimension adjusting member 54. Further, in the case of the electronic component 51 having a large height dimension, the height dimension is adjusted by being embedded so as to reach the back surface side resin layer 43, and when the heat generation of the electronic component 51 is large, A heat conductive resin 55 is applied so as to cover the side and bottom surfaces of the electronic component 51. In any case, the height dimension adjusting member 54 and the heat conductive resin 55 are partially in contact with the core member 41 and the bottom surface portion is exposed from the lower surface of the intermediate layer A.
[0022]
Further, columnar portions 56 and 57 are provided at arbitrary positions of the core member 41, and the columnar portions 56 and 57 are intermediated by electrodes 58, 59, 60 and 61 provided so as to be in contact with both end faces thereof. A signal transmission path or a power transmission path that penetrates the front and back of the layer A is formed. In addition, 62, 63, 64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 75a of the intermediate layer A are electrodes.
[0023]
The lower layer C forms electrode patterns (details will be described later) on both surfaces of the resin layer 76, and the upper layer B also forms electrode patterns (details will be described later) on both surfaces of the resin layer 77. In addition, the electronic components 78 to 82 are surface-mounted on a predetermined electrode pattern, and further, a cover 40a that covers the electronic components 78 to 82 (desirably serving as electromagnetic shielding for EMI countermeasures) Is attached. Although not particularly limited, the electronic components 78, 79, and 81 are capacitors, and the electronic components 80 and 82 are resistors.
[0024]
As described above, the module 40 is based on the flat core member 41 made of a material (Cu, 42 alloy, Invar, etc.) having good electrical conductivity, good thermal conductivity and high rigidity. The front surface side and the back surface side of 41 are built up by resin layers 76 and 77. Here, each of the two resin layers 76 and 77 is made of, for example, an epoxy resin, a polyimide resin, a cyanate ester resin, or a Teflon (registered trademark) resin as a main material (dielectric powder, magnetic powder, etc., if desired). In which the functional powder may be mixed) or an insulating material used for a printed wiring board as a main material, and does not require a reinforcing material such as glass cloth (ie, glass cloth-less It is characteristic in that it is a layer. This is because the bending rigidity of the module 40 is ensured exclusively by the core member 41 which is the base of the intermediate layer A, and a reinforcing material such as a glass cloth is not required.
[0025]
Semiconductor chips (electronic components 48 and 51), capacitors (electronic components 49), and resistors (electronic components 50) are embedded in the four cavities (formed by the bottomless holes 44 to 47) of the core member 41, respectively. It is. Of those electronic components that generate a large amount of heat (electronic components 48 and 51), a part of the bottom surface (and the side surface if necessary) of each component is made of a material with good thermal conductivity (height dimension adjusting member). 54, the heat conductive resin 55) is brought into contact with the core member 41, and is also brought into contact with the upper surface electrode patterns 82 and 83 of the lower layer C. The upper surface electrode patterns 82 and 83 of the lower layer C are connected to the lower surface electrode pattern 86 of the lower layer C via the internal electrodes 84 and 85 of the lower layer C, and eventually the heat generated in the electronic components 48 and 51 is obtained. Is released to the core member 41 through the inner wall surfaces of the bottomless holes 44 and 47, and is also released to the substrate of the electronic device on which the module 40 is mounted via the lower surface electrode pattern 86 of the lower layer C. Thus, a sufficient heat dissipation effect can be obtained.
[0026]
In addition, a semiconductor chip (electronic component 48) having a small height was placed in a cavity (formed by a through hole at the same position as the bottomless hole 44 of the core portion 41) in the lower layer C. Height dimension adjusting member 54 (may be an independent member or may be a plated layer. It has good thermal conductivity and can adjust the height dimension of the electronic component 48. The mounting height is raised to a desired position, and the relationship between the upper surface height position of the electronic component 48 and the upper surface height position of the core member 41 can be appropriately maintained. It has become.
[0027]
In addition, a semiconductor chip (electronic component 51) having a large height dimension is placed in a cavity (formed by a through hole at the same position as the bottomless hole 47 of the core portion 41) formed in the lower layer C. The relationship between the upper surface height position of the electronic component 51 and the upper surface height position of the core member 41 can be maintained appropriately.
[0028]
Patterning of the core member 41 of the intermediate layer A (formation of the bottomless holes 44 to 47 and the columnar portions 56 and 57) should be performed in a state where the back surface side resin layer 43 is bonded to the lower surface of the core member 41. This is because, when the core member 41 is patterned in this state, in particular, the “island” portion in the sea-island structure portion does not fall off, so that the portion can be used as the columnar portions 56 and 57. Therefore, a columnar structure for connecting the front and back of the intermediate layer A (so-called “post”: formed by the columnar portions 55, 57 and the electrodes 58, 59, 60, 61 connected to both ends thereof) is a core member. 41 can be easily formed by physical processing (for example, etching). For example, when the core member 41 is etched with a normal etchant such as ferric chloride, the material of the core member 41 can be Cu, 42 alloy, Invar, or the like in view of the resin physical properties. However, when 42 alloy or invar is selected, it is preferable to perform Cu plating on the surface of 42 alloy or invar from the viewpoint of preventing ion migration or the like.
[0029]
Next, the manufacturing process of the module 40 will be described.
(First step: FIG. 2 (a))
First, a flat core member 41 having good electrical conductivity, good thermal conductivity, and high rigidity, for example, a lower surface of a core member 51 such as Cu, 42 alloy or Invar (when the upper and lower sides face the drawing) A thin film 90 having good electrical conductivity and good thermal conductivity is attached to the lower surface of the back surface side resin layer 43. Stick together.
[0030]
Here, as a material of the back surface side resin layer 43, for example, an epoxy-based, polyimide-based, cyanate ester-based, or Teflon (registered trademark) -based resin material or an insulating material used for a printed wiring board can be used. . Moreover, as the thin film 90, what has said characteristic, typically a copper foil can be used.
[0031]
In addition, you may use what integrated the back surface side resin layer 43 and the thin film 90. FIG. For example, a copper foil with resin may be used. Or you may use what laminated | stacked copper foil on the dry film.
[0032]
(Second step: FIG. 2B)
Next, the core member 41 is patterned to form bottomless holes 44 to 47 and columnar portions 56 and 57. The bottomless holes 44 to 47 become cavities for embedding the electronic components 48 to 51, respectively. The patterning of the core member 41 can be performed by, for example, a subtractive method. In this case, an etchant used in a normal printed wiring board such as ferric chloride or cupric chloride can be used.
[0033]
(Third step: FIG. 2 (c))
Next, with respect to the bottomless holes 44 and 47 corresponding to the electronic parts (electronic parts 48 and 51) that generate a large amount of heat, the bottom-side resin layer 43 below is removed with the same opening shape as the bottomless holes 44 and 47. The thin film 90 is exposed (see the wavy line). The removal of the back surface side resin layer 43 can be performed by, for example, laser ablation or plasma etching.
[0034]
3A and 3B are external views after the third step, where FIG. 3A is a top perspective view and FIG. 3B is a bottom perspective view. Note that FIG. 3 and the above process diagram (FIG. 2) do not correspond exactly. The points to be understood in FIG. 3 are “cavities” and “posts” formed in the core member 41. That is, in FIG. 3, a resin layer 91 (corresponding to the back surface side resin layer 43 in FIG. 2) and a copper foil 92 (corresponding to the thin film 90 in FIG. 2) are bonded to the lower surface of the core member 41. Are formed to form several cavities 93 to 95 (corresponding to the bottomless holes 44 to 47 in FIG. 2) and several posts 96 to 103 (corresponding to the columnar portions 56 and 57 in FIG. 2). .
[0035]
(Fourth step: FIG. 4A)
Next, the height dimension adjusting member 54 is inserted into the bottomless hole 44 at the left end, and the heat conductive resin 104 is applied on the height dimension adjusting member 54. Adhesives 52 and 53 are applied to the second and third bottomless holes 45 and 46 from the left, and a heat conductive resin 55 is applied to the bottomless hole 47 at the right end. The height dimension adjusting member 54 may be an independent member, or may be one obtained by growing a plating such as Cu. Any material having good thermal conductivity and capable of adjusting the height of the electronic component 48 may be used. As the name suggests, the thermally conductive resins 104 and 55 have a function of radiating heat, and also have a function of temporarily fixing the embedded electronic components 48 and 51. The adhesives 52 and 53 need only have a function of fixing the embedded electronic components 49 and 50.
[0036]
Here, the electronic components 49 and 50 that do not require special heat dissipation measures are fixed with adhesives 52 and 53, but the present invention is not limited to this. For example, in the first step (FIG. 2 (a)), when the core member 41 and the resin layer (back side resin layer 43) are laminated and bonded, the resin layer is not fully cured, leaving an uncured portion. Lamination is completed in a state, and when the electronic components 49 and 50 are mounted in the fifth step (FIG. 4B), the adhesive strength of the resin layer is slightly recovered by raising the temperature to a high temperature. , 50 may be fixed. In this way, the application work of the adhesives 52 and 53 can be made unnecessary.
[0037]
(Fifth step: FIG. 4B)
Next, the electronic components 48 to 51 corresponding to the bottomless holes 44 to 47 are mounted. With respect to one electronic component 48 that requires heat dissipation, the heat can be released to the core member 41 and the thin film 90 through the heat conductive resin 104 and the height dimension adjusting member 54, With respect to the electronic component 51, the heat can be released to the core member 41 and the thin film 90 via the heat conductive resin 55.
[0038]
(Sixth step: FIG. 4C)
Next, the core member 41 after mounting the electronic components 48 to 51 is sealed with resin. By this sealing, the surface side resin layer 42 in the first to third embodiments is formed, and by this surface side resin layer 42, the surface of the core member 41, cavities (bottomless holes 44 to 47), and via posts. The gap around the (columnar portions 56, 57) is completely blocked, and the side surface (see the X portion and the Y portion) of the core member 41 is also covered with the surface side resin layer 42.
[0039]
Here, as the material of the surface-side resin layer 42, for example, an epoxy-based, polyimide-based, cyanate ester-based, or Teflon (registered trademark) -based resin material or an insulating material used for a printed wiring board can be used. .
[0040]
FIG. 5 is an external view (a) after the fifth step and an external view (b) after the sixth step. Note that FIG. 5 and the above process diagram (FIG. 4) do not correspond exactly. The points to be understood in FIG. 5 are the mounting state of the electronic component in the “cavity” formed in the core member 41 and the sealing state by the resin (surface-side resin layer 42). That is, in FIG. 5, corresponding electronic components 105 to 107 (corresponding to the electronic components 48 to 51 in FIG. 4) are mounted in the cavities 93 to 95 formed in the core member 41, respectively. The core member 41 in a state in which 107 is mounted is completely sealed with a resin 108 (corresponding to the front surface side resin layer 42 in FIG. 4). In FIG. 5B, the side surface of the core member 41 after being sealed with the resin 108 is exposed, but this is for convenience of illustration. Actually, the side surface of the core member 41 is also completely covered with the resin 108.
[0041]
(Seventh step: FIG. 6A)
Next, the thin film 90 is patterned. By this patterning, a heat radiation pattern 83 for directly releasing heat is formed in the thin film 90 through the thermally conductive resin 55 among the electronic components 48 and 51 requiring heat radiation countermeasures. That is, the thin film 90 is etched out so as to leave only the heat radiation pattern 83.
[0042]
(Eighth step: FIG. 6B)
Next, small holes 109, 110, 111, 112, 113, 114, 115, 116, 117, 118, 118 a, 119, 120, 121, 122, 123, are formed in the front surface side resin layer 42 and the back surface side resin layer 43, respectively. Open 124, 125, 125a. For example, the resin of each layer is changed to CO₂After partial removal with a gas laser, UV laser, excimer laser, or the like, the resin residue is removed with permanganic acid or plasma ashing, whereby small holes 109, 110, 111, 112, 113, 114, 115, 116 are obtained. 117, 118, 118a, 119, 120, 121, 122, 123, 124, 125, 125a are formed.
[0043]
(Ninth step: FIG. 6C)
Next, copper plating is applied to the small holes 109110, 111, 112, 113, 114, 115, 116, 117, 118, 118a, 119, 120, 121, 122, 123, 124, 125, 125a, and the electronic components 48-49. Through the electrodes 62, 63, 64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 75a and the core member 41 for electrical interlayer connection with the terminals of Electrodes 58 to 61 for performing the interlayer connection are formed. In addition, in order to ensure the adhesiveness of resin and plated copper, the surface of the resin may be roughened by permanganic acid or the like as necessary to increase the surface area. Reference numerals 126 to 154 denote electrodes or wiring patterns formed on the exposed surfaces of the front surface side resin layer 42 and the rear surface side resin layer 43. By the ninth step, the intermediate layer A in FIG. 1 is formed.
[0044]
(Tenth step: FIG. 7A)
Next, the upper layer B and the lower layer C in FIG. 1 are formed by laminating resins to the front surface side resin layer 42 and the back surface side resin layer 43 respectively and forming necessary solder resist patterns on the front and back surfaces of those resins. It is done.
[0045]
(Eleventh step: FIG. 7B)
Next, the vicinity of the four side end portions of the upper layer B, the intermediate layer A, and the lower layer C is cut to expose the end surfaces (see the X and Y portions) of the core member 41.
[0046]
8A and 8B are external views after the eleventh step. FIG. 8A is a top perspective view, and FIG. 8B is a bottom perspective view. The important point to understand in FIG. 8 is that the core member 41 is exposed from each end face of the four sides of the substrate.
[0047]
After executing the above steps, required surface mount components (electronic components 78 to 82 in FIG. 1) are attached, and if necessary, a cover 40a is attached, thereby completing the module 40 shown in FIG.
[0048]
The module 40 having such a structure is based on (1) a flat core member 41 made of a material (Cu, 42 alloy, Invar, etc.) having good electrical conductivity, good thermal conductivity and high rigidity. Therefore, the bending stress of the substrate can be received by the rigidity of the core member 41, and undesirable substrate deformation can be avoided or suppressed. Therefore, since a reinforcing material such as a glass cloth is not required, various problems related to the glass cloth (problem of ion migration and increase in manufacturing cost associated with cutting of the glass cloth at the time of forming the cavity) do not occur. In addition, when “sea island” is formed in a required portion in a state where the resin (back surface side resin layer 43) is attached to one surface (back surface in the embodiment) of the core member 41, the “island” portion does not fall off. Therefore, the portion can be used as the island portions 56 and 57. In addition, the electrical signal transmission path and the power transmission path between the layers can be simply configured through the island portions 56 and 57, and the module design can be facilitated. (3) Core member 41 Cavities (bottomless holes 44 to 47) can be formed in the substrate, and the electronic components 48 to 51 can be easily embedded in the cavities, and the mounting density of the substrate can be improved in combination with the surface mounting. (4) Further, when embedding an electronic component having a large height dimension or a small height dimension, the height dimension adjusting member 54 is inserted or the hole of the back surface side resin layer 43 is used to increase the height of the electronic component. The height dimension can be easily adjusted, and the upper surface height position of the core member 41 can be set appropriately so that the upper surface height position of the electronic component does not exceed. For this reason, the load at the time of manufacturing the multilayer substrate can be received by the core member 41, and damage to the electronic component can be prevented. (5) When the heat of the electronic component is released, the core member 41 is used as a heat dissipation path. The heat dissipation pattern (electrode pattern 166 in FIG. 8B) formed on the exposed surface of the lower layer C can be used as a heat dissipation path, and the electronic components 48 and 51 that generate particularly large heat are embedded. The module 40 can be suitable for use.
[0049]
(6) Moreover, since the core member 41 is actively exposed by cutting each end face of the four sides of the substrate, for example, as shown in FIG. The portion 41b located at the lower right end of the core member 41 in the drawing can be exposed to the outside. These parts 41a and 41b are similarly connected to electrodes 62, 71, 70, and 75a exposed to the outside, and in short, are used as transmission paths for power, ground, signals, etc. The signal transmission path can be taken out from the side surface of the substrate through the exposed portions 41a and 41b (and the electrodes 62, 71, 70, and 75a). Therefore, since the exposed portions 41a and 41b are not signals transmitted through the prior art pins 8 and 8 (see FIG. 12) described at the beginning, for example, the signal delay in high frequency applications can be reduced. Obtainable.
[0050]
The present invention is not limited to the above embodiment. It goes without saying that various modifications are included within the scope of the idea of the invention.
FIG. 9 is a diagram showing a first modification. In this figure, a flat core member 200 made of a material (Cu, 42 alloy, Invar, etc.) having good electrical conductivity, good thermal conductivity and high rigidity includes a cavity 201 for mounting electronic components and The signal transmission parts 202 and 203 are formed, and each of the front and back surfaces of the core member 200 is made of an epoxy-based, polyimide-based, cyanate ester-based, or Teflon (registered trademark) -based resin (dielectric material as desired). It may be sealed with insulating resin layers 204 and 205 whose main material is an insulating material used for a printed wiring board. Further, cutting or the like is performed in the vicinity of the four side end portions of the composite multilayer substrate 206 having such a structure, and at least the end faces 202a and 203a of the signal transmission portions 202 and 203 formed on the core member 200 are externally provided. It is supposed to be exposed.
[0051]
In such a structure, an arbitrary electronic component such as a semiconductor chip is mounted in the cavity 201, and the electrodes of the electronic component and the signal transmission units 202 and 203 are connected by, for example, bonding wires or the like. Supply of a power supply potential and ground potential to an electronic component, or exchange of input / output signals can be performed via the end faces 202a and 203a of the signal transmission units 202 and 203. Since signals are directly transmitted to the respective end faces 202a and 203a of the signal transmission units 202 and 203, for example, signals can be transmitted without using the pins 8 and 8 (see FIG. 12) described at the beginning. Thus, it is possible to obtain a special effect that transfer loss can be reduced.
[0052]
FIG. 10 is a diagram showing a second modification. In this figure, 206 corresponds to the core member 41 of FIG. 1 (hereinafter also referred to as the core member), and 207 corresponds to the back surface side resin layer 43 of FIG. On the surface of the bottomless hole or the bottomed hole in which at least the electronic component of the core member 206 is embedded and mounted, fine irregularities 206a are formed, and so-called “roughening treatment” is performed.
[0053]
According to this, as shown in (b), when the core member 206 is covered with the sheet-like insulating resin 208 (corresponding to the surface-side resin layer 42 in FIG. 1), the unevenness 206a on the surface of the core member 206 is formed. Since the sheet-like insulating resin 208 and the core member 206 are in contact with each other (see the portion indicated by the symbol Z in the figure), the substantial contact area between both is enlarged by the unevenness 206a, and the sheet-like insulating resin 208 and the core are By making the bonding strength with the member 206 firm, inconveniences such as peeling can be avoided and the reliability can be improved.
[0054]
In addition, FIG. 11 is a figure which shows the surface photograph of the core member 206 for comparing before a roughening process (a) and after a roughening process (b). These photographs were taken with an SEM (scanning electron microscope). The photographing conditions are all 15 KV (applied voltage) and × 5000 (magnification). Comparing the two, in (a), only a negligible minute and smooth undulation is observed, whereas in (b), the surface is filled with minute irregularities that are repeated at almost equal intervals. Obviously, traces of surface roughening are observed in (b).
Furthermore, by providing a wiring pattern in the resin layer that covers the core member continuous to the exposed portion of the end surface of the core member, the area of the exposed conductor when the exposed portion is used as a terminal for electrical connection is reduced. It can be expanded to increase the bonding strength.
In addition, by providing a wiring pattern on at least the lower surface side resin layer covering the core member continuous with the exposed portion of the end surface of the core member, the solder wet-up to the exposed portion of the end surface of the core member is improved. be able to.
[0055]
【The invention's effect】
  According to the composite multilayer substrate according to the present invention, since the exposed portion is provided on the end surface excluding the front and back surfaces of the core member, the exposed portion can be used as a terminal for electrical connection. Provided is a composite multilayer substrate that can transmit signals without any problem and can reduce transfer loss in high frequency applications, and a module using the sameit can.
  Furthermore, by providing a wiring pattern in the resin layer covering the core member continuous to the exposed portion of the end surface of the core member, the area of the exposed conductor when the exposed portion is used as a terminal for electrical connection is reduced. It can be expanded to increase the bonding strength.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view of a module made by applying the technical idea of the present invention.
FIG. 2 is a manufacturing process diagram (first process to third process) of the module 40;
FIG. 3 is an external view after a third step.
FIG. 4 is a manufacturing process diagram (fourth process to sixth process) of the module 40;
FIG. 5 is an external view after a fifth step.
6 is a manufacturing process diagram (seventh process to ninth process) of the module 40; FIG.
7 is a manufacturing process diagram of the module 40 (tenth process to eleventh process). FIG.
FIG. 8 is an external view after an eleventh step.
FIG. 9 is a diagram showing a first modification.
FIG. 10 is a diagram showing a second modification.
FIG. 11 is a diagram showing the surface state before and after the roughening treatment.
FIG. 12 is a cross-sectional view of a conventional composite multilayer substrate.
[Explanation of symbols]
41 Core member
42 Surface side resin layer (resin layer)
43 Back side resin layer (resin layer)
44 to 47 Bottomless hole
48-51 electronic components
40 Composite multilayer board
202, 203 Signal transmission unit

Claims (3)

A flat core member made of a material having good electrical conductivity, good thermal conductivity and high rigidity;
A resin layer covering the core member;
A bottomed hole formed in the core member through the front and back of the core member or a bottomed hole that does not penetrate the front and back; and
In the composite multilayer substrate used by embedding and mounting electronic components with resin in the bottomless hole or the bottomed hole,
Cutting a portion following the end surface excluding the bottomed hole or the bottomed hole forming portion of the core member , the cutting portion as a signal transmission unit, and
Expose the end face of this signal transmission part to the outside,
A composite multilayer board characterized in that power supply, signal input or signal output is performed to the electronic component using the signal transmission unit . The composite multilayer substrate according to claim 1 , wherein a wiring pattern is provided in a resin layer that covers the core member continuous with an exposed portion of the end surface of the core member. A module comprising the composite multilayer substrate according to claim 1 .

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