JP5894221B2 - Interposer, mounting structure using the same, and electronic device - Google Patents

Description

  The present invention relates to an interposer used for electronic devices (for example, various audiovisual devices, home appliances, communication devices, computer devices and peripheral devices thereof), and a mounting structure using the interposer.

  2. Description of the Related Art Conventionally, as a mounting structure in an electronic device, an electronic component mounted on a wiring board is used.

  Patent Document 1 describes a mounting structure that includes a wiring board and a bare chip that is flip-chip mounted on the wiring board.

  Thus, when the bare chip is flip-chip mounted on the wiring board, the difference in thermal expansion coefficient between the wiring board and the bare chip when heat is applied to the mounting structure during mounting or operation of the bare chip. As a result, thermal stress is generated in the connection portion between the wiring board and the bare chip, and the thermal stress may be applied to the electrode of the bare chip having low durability to break down. As a result, the electrical reliability of the mounting structure It becomes easy to fall.

  On the other hand, Patent Document 2 includes a wiring board, an electronic element mounted on the wiring board, and an interposer interposed between the wiring board and the electronic element. There is described a mounting structure having a base made of a semiconductor material or glass and a conductor-embedded through hole that penetrates the base and is filled with a conductor.

  Thus, an interposer whose base is made of a semiconductor material or glass has a smaller difference in thermal expansion coefficient from the electronic element than the wiring board, and reduces the thermal stress generated at the connection between the interposer and the electronic element. As a result, the thermal stress applied to the electrode of the electronic element can be reduced.

  However, since the coefficient of thermal expansion of the substrate made of such a semiconductor material or glass is smaller than the coefficient of thermal expansion of the conductor-embedded through-hole, when heat is applied to the interposer during mounting or operation of the electronic element, When the conductor-embedded through hole is thermally expanded larger than the base, stress is applied to the inner wall of the penetrating portion, and as a result, cracks tend to occur from the inner wall of the penetrating portion toward the inside of the base. As a result, the conductive material of the conductor-embedded through hole penetrates into the crack, so that the conductor-embedded through holes are likely to be short-circuited, and the electrical reliability of the interposer is likely to be lowered.

JP-A-11-214449 JP 2004-31574 A

  The present invention provides an interposer that meets the demand for improving electrical reliability, a mounting structure using the interposer, and an electronic apparatus.

An interposer according to an aspect of the present invention includes an inorganic insulating layer in which a plurality of through holes along the thickness direction are formed, a resin layer disposed on one main surface of the inorganic insulating layer, and the through holes. The through-conductor has a wide portion located in the resin layer having a width larger than that of the opening on the inorganic insulating layer side of the resin layer in a cross-section along the through-direction. The inorganic insulating layer includes a first inorganic insulating particle bonded to each other and a second inorganic insulating particle having a particle size larger than that of the first inorganic insulating particle bonded to each other via the first inorganic insulating particle. Particles .

  A mounting structure according to an embodiment of the present invention includes a wiring board, the interposer according to claim 1 mounted on the wiring board, and an electronic component mounted on the interposer.

  According to the interposer according to one aspect of the present invention, by reducing the elastic modulus of the inorganic insulating layer, when stress is applied to the inorganic insulating layer, cracks in the inorganic insulating layer are reduced, and thus electrical reliability is improved. An interposer with excellent properties can be obtained.

1A is a cross-sectional view of the mounting structure according to the first embodiment of the present invention cut in the thickness direction, and FIG. 1B is an enlarged cross-sectional view of the R1 portion of FIG. FIG. 1C schematically shows a state in which the two first inorganic insulating particles are combined. 2A to 2D are cross-sectional views taken in the thickness direction for explaining the manufacturing process of the mounting structure shown in FIG. 1, and FIG. 2E shows the portion R2 in FIG. It is sectional drawing expanded. 3A, 3C, and 3D are cross-sectional views cut in the thickness direction illustrating the manufacturing process of the mounting structure shown in FIG. 1, and FIG. 3B is a cross-sectional view of FIG. It is sectional drawing which expanded and showed R3 part. FIG. 4 is a cross-sectional view of the mounting structure according to the second embodiment of the present invention cut in the thickness direction. FIG. 5 is a cross-sectional view of the mounting structure according to the third embodiment of the present invention cut in the thickness direction.

(First embodiment)
Hereinafter, a mounting structure including an interposer according to a first embodiment of the present invention will be described in detail based on the drawings.

  A mounting structure 1 shown in FIG. 1A is used for electronic devices such as various audiovisual devices, home appliances, communication devices, computer devices or peripheral devices thereof, and is an external circuit such as a motherboard. Is electrically connected. The mounting structure 1 includes an electronic component 2, a wiring board 3 on which the electronic component 2 is mounted, an interposer 4 interposed between the electronic component 2 and the wiring board 3, the interposer 4 and the electronic component 2. A first bump 5a that electrically connects the wiring board 3, a second bump 5b that electrically connects the interposer 4 and the wiring board 3, and a third bump 5c that electrically connects the wiring board 3 and an external circuit. Is included.

  The electronic component 2 is mounted on the wiring board 3 via the interposer 4 and is, for example, a semiconductor element such as an LSI or an IC. As this semiconductor element, a logic or memory semiconductor element such as a CPU or MPU can be used, and the base material includes a semiconductor material such as silicon, germanium, gallium arsenide, gallium arsenide phosphorus, gallium nitride, or silicon carbide. It is out. The electronic component 2 has a thickness set to, for example, 0.05 mm to 0.8 mm, a coefficient of thermal expansion in each direction, for example, set to 3 ppm / ° C. to 5 ppm / ° C., and a Young's modulus, for example, 100 GPa to 150 GPa Is set to

  Here, in the mounting structure 1 of the present embodiment, the electronic component 2 is desirably a logic semiconductor element. This logic-based semiconductor element has a larger number of terminals and finer wiring than a memory-based semiconductor element, and the circuit is likely to be disconnected when stress is applied. Electrical connection reliability tends to decrease. Therefore, by interposing the interposer 4 between the electronic component 2 and the wiring board 3, the stress applied to the circuit of the electronic component 2 is relieved, and the electrical connection reliability between the electronic component 2 and the wiring board 3 is reduced. Can increase the sex.

  The thickness of the electronic component 2 is obtained by observing a cross section of the electronic component 2 cut along the thickness direction (Z direction) with a scanning electron microscope, and calculating an average value of the length along the thickness direction (Z direction). Is measured. Moreover, the thermal expansion coefficient of the electronic component 2 is measured by a measuring method according to JISK7197-1991 using a commercially available TMA apparatus. Moreover, the Young's modulus of the electronic component 2 is measured using Nano Indentor XP / DCM manufactured by MTS Systems. Hereinafter, the thickness, thermal expansion coefficient, and Young's modulus of each member are measured in the same manner as the electronic component 2 described above.

  The wiring substrate 3 is a resin-made build-up substrate, and includes a core substrate 6 and a pair of build-up portions 7 formed above and below the core substrate 6. The wiring board 3 is set to have a thickness of, for example, 0.3 mm to 1.8 mm, a thickness of, for example, 2 to 20 times that of the electronic component 2, and a coefficient of thermal expansion in the plane direction (XY plane direction). Is set to, for example, 13 ppm / ° C. to 30 ppm / ° C., the coefficient of thermal expansion in the plane direction is set to, for example, 3 times to 8 times that of the electronic component 2, and the Young's modulus is set to 5 GPa to 40 GPa.

  The core substrate 6 increases the rigidity of the wiring substrate 3, and includes a resin substrate 8 in which a through hole penetrating in the thickness direction is formed, a through hole conductor 9 formed in a cylindrical shape along the inner wall of the through hole, And an insulator 10 formed in a columnar shape inside the through-hole conductor 9.

  The resin substrate 8 is for increasing the rigidity of the core substrate 6. For example, epoxy resin, bismaleimide triazine resin, cyanate resin, polyparaphenylene benzbisoxazole resin, wholly aromatic polyamide resin, polyimide resin, aromatic liquid crystal polyester resin And resin materials such as polyetheretherketone resin or polyetherketone resin. Moreover, you may include the base material which consists of fibers, or an inorganic insulating filler.

  The through-hole conductor 9 electrically connects the upper and lower buildup portions 7 of the core substrate 6 and includes a conductive material such as copper, silver, gold, aluminum, nickel, or chromium.

  The insulator 10 forms a support surface of a via conductor 13 to be described later. For example, a resin such as a polyimide resin, an acrylic resin, an epoxy resin, a cyanate resin, a fluorine resin, a silicon resin, a polyphenylene ether resin, or a bismaleimide triazine resin. Contains material.

  On the other hand, the build-up portion 7 is formed with via holes penetrating in the thickness direction, the insulating layer 11 disposed on the core substrate 6, the wiring layer 12 disposed on the core substrate 6 or on the insulating layer 11, and via holes. And a via conductor 13 electrically connected to the wiring layer 12. The wiring layer 12 and the via conductor 13 are electrically connected to each other, and constitute a wiring portion including a grounding wiring, a power supply wiring, or a signal wiring.

The insulating layer 11 has a function as a support member of the wiring layer 12 and a function as an insulating member that suppresses a short circuit between the wiring layers 12, and the insulating layer 11 includes, for example, an epoxy resin, a bismaleimide triazine resin, and a cyanate. Resin materials such as resin, polyparaphenylene benzbisoxazole resin, wholly aromatic polyamide resin, polyimide resin, aromatic liquid crystal polyester resin, polyetheretherketone resin or polyetherketone resin are included.

  The wiring layer 12 is separated from each other in the thickness direction via the insulating layer 11 and includes, for example, a conductive material such as copper, silver, gold, aluminum, nickel, or chromium.

  The via conductor 13 connects the wiring layers 12 spaced apart from each other in the thickness direction, and is formed in a columnar shape (tapered shape) in which the cross-sectional area in the plane direction decreases toward the core substrate 6. For example, a conductive material of copper, silver, gold, aluminum, nickel, or chromium is included.

  On the other hand, the interposer 4 functions as a connecting member for the electronic component 2 and the wiring board 3, and is in contact with the base 14 in which the through hole P is formed along the thickness direction and one main surface of the base 14. And a through conductor 16 disposed in the through hole P and having one end electrically connected to the conductive layer 15.

  The base 14 functions as a support member and an insulating member for the interposer 4, is in contact with the inorganic insulating layer 17 and one main surface of the inorganic insulating layer 17, and has a smaller thickness than the inorganic insulating layer 17. And a resin layer 18. The substrate 14 is set to have a thickness of, for example, 30 μm to 200 μm, a thickness of, for example, 0.2 to 0.8 times that of the electronic component 2, and a thickness of, for example, 0.015 to 0 of the wiring board 3. .5 times or less, the coefficient of thermal expansion in each direction is set to, for example, 3 ppm / ° C. or more and 7 ppm / ° C. or less, and the coefficient of thermal expansion in the plane direction is, for example, 0.75 times or more and 1.25 times that of the electronic component 2. The coefficient of thermal expansion in the plane direction is set to, for example, 0.2 to 0.4 times that of the wiring board 3, the Young's modulus is set to, for example, 10 GPa to 45 GPa, and the Young's modulus is an electronic component. For example, 2 is set to 0.08 times or more and 0.35 times or less.

  The inorganic insulating layer 17 is a main part of the base 14 and has a function of making the base 14 have a low coefficient of thermal expansion. The thickness of the inorganic insulating layer 17 is set to, for example, 30 μm or more and 200 μm or less. The expansion coefficient is set to 0 ppm / ° C. or more and 7 ppm / ° C. or less, the thermal expansion coefficient in the plane direction is set to 0.1 to 2 times that of the electronic component 2, and the thermal expansion coefficient in the plane direction is set to the wiring board 3. The Young's modulus is set to, for example, 10 GPa to 45 GPa, the Young's modulus is set to, for example, 0.08 to 0.35 times that of the electronic component 2, and the dielectric The tangent is set to, for example, 0.0001 or more and 0.01 or less. In addition, the dielectric loss tangent of the inorganic insulating layer 17 is measured by a resonator method according to JIS R1627-11996. Hereinafter, the dielectric loss tangent of each member is measured in the same manner as the inorganic insulating layer 17.

  As shown in FIG. 1B, the inorganic insulating layer 17 has a particle diameter set to 3 nm or more and 110 nm or less, and is bonded to each other, and the first inorganic insulating particles 17a are bonded to each other. And a second inorganic insulating particle 17b having a large diameter and a particle size of 0.5 μm or more and 5 μm or less and bonded to each other via the first inorganic insulating particle 17a. The first inorganic insulating particles 17a are bonded to each other through a boundary surface 17a1 as shown in FIG.

The first inorganic insulating particles 17a and the second inorganic insulating particles 17b are confirmed by observing the polished surface or fracture surface of the inorganic insulating layer 17 with a field emission electron microscope. The particle size of the inorganic insulating particles 17b is obtained by observing the polished surface or fractured surface of the inorganic insulating layer 17 with a field emission electron microscope, photographing a cross section enlarged so as to include particles of 20 particles or more and 50 particles or less, It is measured by measuring the maximum diameter of each particle in the enlarged cross section.

  The first inorganic insulating particles 17a and the second inorganic insulating particles 17b contain silicon oxide. As a result, by reducing the thermal expansion coefficient in each direction of the inorganic insulating layer 17, the thermal expansion coefficient in the planar direction of the interposer 4 can be brought close to the thermal expansion coefficient in the planar direction of the electronic component 2. As a result, when heat is applied to the interposer 4 and the electronic component 2, the connection reliability between the interposer 4 and the electronic component 2 can be improved.

  The first inorganic insulating particles 17a and the second inorganic insulating particles 17b may be made of only silicon oxide. In addition to silicon oxide, aluminum oxide, magnesium oxide, calcium oxide, aluminum nitride, and hydroxide You may use what contains inorganic insulation materials, such as aluminum or calcium carbonate. In addition, as for the 1st inorganic insulating particle 17a and the 2nd inorganic insulating particle 17b, it is desirable to contain 65 to 100 weight% of silicon oxides.

  Moreover, it is desirable that the silicon oxide constituting the first inorganic insulating particles 17a and the second inorganic insulating particles 17b is in an amorphous state. As a result, since the anisotropy of the coefficient of thermal expansion due to the crystal structure of the inorganic insulating layer 17 can be reduced, when heat is applied to the mounting structure 1, the inorganic insulating layer is cooled during heating. The shrinkage of the layer 17 can be made more uniform in each direction, and as a result, the reliability of electrical connection between the interposer 4 and the electronic component 2 can be improved.

The silicon oxide in the amorphous state has a crystal phase region set to, for example, less than 10% by volume, and is preferably set to less than 5% by volume. The volume ratio of the crystal phase region in the inorganic insulating material is measured as follows. First, a plurality of comparative samples containing 100% crystallized sample powder and amorphous powder at different ratios were prepared, and the comparative samples were prepared as X
A calibration curve indicating the relative relationship between the measured value and the volume ratio of the crystal phase region is created by measurement using a line diffraction method. Next, the investigation sample to be measured is measured by the X-ray diffraction method, the measured value is compared with the calibration curve, and the volume ratio of the crystal phase region is calculated from the measured value, thereby obtaining the crystal of the investigation material. The volume ratio of the phase region is measured.

  The first inorganic insulating particles 17a are preferably spherical. As a result, the filling density of the first inorganic insulating particles 17a can be increased, the first inorganic insulating particles 17a can be more firmly bonded, and the rigidity of the inorganic insulating layer 17 can be increased. The second inorganic insulating particles 17b are preferably spherical. As a result, the stress on the surface of the second inorganic insulating particle 17b can be dispersed, and the generation of cracks in the inorganic insulating layer 17 starting from the surface of the second inorganic insulating particle 17b can be reduced.

  On the other hand, the resin layer 18 is interposed between the inorganic insulating layer 17 and the conductive layer 15 and contains a resin material. The resin layer 18 has a thickness set to, for example, 0.5 μm or more and 3 μm or less, a thickness set to, for example, 0.002 to 0.1 times that of the inorganic insulating layer 17, and thermal expansion in the planar direction and the thickness direction. The rate is set to 50 ppm / ° C. to 120 ppm / ° C., the Young's modulus is set to, for example, 0.05 GPa to 5 GPa, and the Young's modulus is set to, for example, 0.001 to 0.2 times that of the inorganic insulating layer 17. The Young's modulus is set to be, for example, 0.0002 times to 0.05 times that of the conductive layer 15.

As a resin material which comprises the resin layer 18, resin materials, such as an epoxy resin, a polyurethane resin, cyanate resin, or a polyimide resin, can be used, for example. Further, the resin layer 18 may include an inorganic insulating filler made of an inorganic insulating material such as silicon oxide in order to enhance flame retardancy. This inorganic insulating filler has a particle size of, for example, 0.01 μm or more and 0.5 μm.
m or less, and the content in the resin material is set to, for example, 0.3 volume% or more and 10 volume% or less.

  In addition, the particle size of the inorganic insulating filler is obtained by observing the polished surface or fractured surface of the resin layer 18 with a field emission electron microscope, and photographing an enlarged cross section so as to include particles of 20 particles or more and 50 particles or less, It is measured by measuring the maximum diameter of each particle in the enlarged cross section. The content (volume%) of the inorganic insulating filler in the resin layer 18 is determined by photographing the polished surface of the resin layer 18 with a field emission electron microscope and using an image analyzer or the like to occupy the inorganic insulating filler in the resin layer 18. It is measured by calculating the average value of the area ratio (area%) and considering the content (volume%).

  The conductive layer 15 is disposed on one main surface (main surface on the electronic component 2 side) of the base 14 and has a function as a connection pad with the electronic component 2 and a function as wiring. As a result, the connection reliability between the one end of the through conductor 16 and the electrode of the electronic component 2 can be increased by the conductive layer 15. The conductive layer 15 includes a conductive material such as copper, silver, gold, aluminum, nickel, or chromium. The conductive layer 15 has a coefficient of thermal expansion in each direction set to 12 ppm / ° C. or more and 20 ppm / ° C. or less, and a coefficient of thermal expansion in each direction set to 3 to 7 times that of the inorganic insulating layer 17. The Young's modulus is set to 80 GPa or more and 200 GPa or less.

The through conductor 16 electrically connects the electronic component 2 and the wiring board 3, and is formed in a columnar shape (tapered shape) whose cross-sectional area in the planar direction decreases toward the electronic component 2. Including conductive material of silver, gold, aluminum, nickel or chromium. The through conductors 16 is set to the cross-sectional area in the planar direction, for example 0.0001 mm ² or more 0.01 mm ² or less, the thermal expansion coefficient in each direction is set to 20 ppm / ° C. or less than 12 ppm / ° C., each direction The thermal expansion coefficient is set to 3 to 7 times that of the electronic component 2, the thermal expansion coefficient in each direction is set to 3 to 7 times that of the inorganic insulating layer 17, and the Young's modulus is 80 GPa to 200 GPa. Is set to

  The through conductor 16 is filled in the through hole P. As a result, even when the diameter of the through hole P is further reduced and miniaturized, the reliability of electrical connection between the wiring board 3 and the electronic component 2 can be improved by reducing the disconnection in the through conductor 16.

  The first bump 5a functions as an electrical connection member between the electronic component 2 and the interposer 4, and is interposed between the electronic component 2 and the conductive layer 15 of the interposer 4, for example, lead, tin, It is made of a conductive material such as solder containing silver, gold, copper, zinc, bismuth, indium or aluminum.

  The second bump 5 b functions as an electrical connection member between the interposer 4 and the wiring board 3, and is interposed between the through conductor 16 of the interposer 4 and the uppermost wiring layer 12 of the wiring board 3. The conductive material is the same as that of the first bump 5a.

  The third bump 5c functions as an electrical connection member between the wiring board 3 and the external circuit, and is formed on the main surface of the lowermost wiring layer 12 of the wiring board 3. The same conductive material is used.

  By the way, the thermal expansion coefficient in each direction of the through conductor 16 is larger than that of the inorganic insulating layer 17 and the electronic component 2. Therefore, when the inorganic insulating layer 17 containing silicon oxide having a small coefficient of thermal expansion in each direction is used, the difference in the coefficient of thermal expansion in the planar direction between the inorganic insulating layer 17 and the electronic component 2 is easily reduced. The difference in coefficient of thermal expansion between the insulating layer 17 and the through conductor 16 in the planar direction tends to be large.

  On the other hand, in the interposer 4 of the present embodiment, the inorganic insulating layer 17 includes first inorganic insulating particles 17a bonded to each other. Here, the inorganic insulating layer 17 has a small Young's modulus and is easily elastically deformed as compared with silicon (Young's modulus of about 130 GPa) or silica glass (Young's modulus of about 75 GPa). This is because the first inorganic insulating particles 17a having a particle size of, for example, 3 nm to 110 nm and extremely fine are bonded to each other, so that an ultrafine gap is formed between the first inorganic insulating particles 17a. It is presumed to be due to the ease. Moreover, since the first inorganic insulating particles 17a having a particle size of, for example, 3 nm to 110 nm and extremely fine are produced under a low temperature condition as compared with silica glass as described later, the first inorganic insulating particles In the crystal structure of silicon oxide contained in 17a, since the three-membered ring structure is small and the multi-membered ring structure having five or more members is likely to increase, the Young's modulus of the first inorganic insulating particles 17a itself tends to be small. Presumed to be due.

  Therefore, the inorganic insulating layer 17 has a small Young's modulus and is easily elastically deformed. Therefore, when heat is applied to the interposer 4, the inorganic insulating layer 17 is caused by a difference in thermal expansion coefficient between the inorganic insulating layer 17 and the through conductor 16. Thus, the thermal stress applied to the inorganic insulating layer 17 is relaxed by elastic deformation. Therefore, it is possible to reduce the occurrence of cracks from the inner wall of the through hole P due to the thermal stress toward the inside of the inorganic insulating layer 14, thereby reducing the short circuit between adjacent through conductors 16.

  The inorganic insulating layer 17 includes second inorganic insulating particles 17b having a particle size larger than that of the first inorganic insulating particles 17a and bonded to each other through the first inorganic insulating particles 17a. Therefore, when a crack extends from the inner wall of the through-hole P toward the inside of the inorganic insulating layer 14, when the crack reaches the second inorganic insulating particle 17b having a large surface area, the stress of the crack is reduced in the second inorganic insulating particle 17b. Since it is dispersed on the surface, extension of cracks can be suppressed, and as a result, a short circuit between adjacent through conductors 16 can be reduced.

  Further, the inorganic insulating layer 17 is formed with a plurality of voids V surrounded by the first inorganic insulating particles 17a and the second inorganic insulating particles 17b. Therefore, when a crack extends from the inner wall of the through hole P toward the inside of the inorganic insulating layer 14, the extension direction changes when the crack reaches the gap V, and therefore the distance until the crack reaches the adjacent through conductor 16. Becomes longer and energy required for crack extension is easily consumed. Therefore, the possibility that the cracks reach the adjacent through conductors 16 can be reduced, and as a result, a short circuit between the adjacent through conductors 16 can be reduced.

  As described above, in the interposer 4 of the present embodiment, it is possible to reduce the occurrence of cracks extending from the inner wall of the through hole P toward the inside of the inorganic insulating layer 17 and the possibility of reaching the adjacent through conductor 16. Therefore, the short circuit between the adjacent through conductors 16 can be reduced, and as a result, the interposer 4 excellent in electrical reliability can be obtained.

  Further, as described above, since the Young's modulus of the inorganic insulating layer 17 becomes small and is easily elastically deformed, cracks along the thickness direction of the inorganic insulating layer 17 can be reduced, and as a result, the conductive layer caused by the crack. 15 disconnections can be reduced.

  The void V formed in the inorganic insulating layer 17 is filled with air. Therefore, the dielectric loss tangent of the inorganic insulating layer 17 can be increased by the gap V, and consequently the signal transmission characteristics of the conductive layer 15 and the through conductor 16 can be improved.

The ratio of the volume of the void V to the total volume of the inorganic insulating layer 17 (the total value of the volumes of the first inorganic insulating particles 17a, the second inorganic insulating particles 17b, and the void V) is, for example, 2% by volume or more and 12% by volume.
It is set as follows. Note that the ratio (volume%) of the volume of the void V to the total volume of the inorganic insulating layer 17 is obtained by photographing the polished surface of the inorganic insulating layer 17 with a field emission electron microscope and using an image analysis apparatus or the like. It is measured by calculating the average value of the area ratio (area%) of the voids V occupying the entire layer 17 and considering it as the content (volume%).

  In addition, the gap V has a first gap V1 and a second gap V2 having an elongated shape with an aspect ratio larger than that of the first gap V1 in the cross section along the thickness direction of the inorganic insulating layer 17, The second gap V <b> 2 has a longitudinal direction that intersects both the thickness direction of the inorganic insulating layer 17 and the surface direction (plane direction) of the inorganic insulating layer 17 in a cross section along the thickness direction of the inorganic insulating layer 17. Therefore, the volume of the gap V is efficiently increased by the first gap V1 having a small aspect ratio, the dielectric loss tangent of the inorganic insulating layer 17 is increased, and the second gap V2 having a large aspect ratio is inorganic from the inner wall of the through hole P. It is possible to efficiently change the extending direction of the cracks extending into the insulating layer 17.

  The aspect ratio of the first void V1 is set to 1 or more and 4 or less, for example, and the volume ratio with respect to the entire inorganic insulating layer 17 is set to 1 volume% or more and 10 volume% or less, for example. In addition, the second void V2 has an aspect ratio set to, for example, 5 or more and 20 or less, an aspect ratio set to, for example, 1.2 to 20 times that of the first void V1, and a volume ratio with respect to the entire inorganic insulating layer 17. Is set to, for example, 1 volume% or more and 10 volume% or less.

  In addition, the aspect ratio of the 1st space | gap V1 and the 2nd space | gap V2 image | photographs the grinding | polishing surface of the inorganic insulating layer 17 with a field emission electron microscope, and is measured using an image analysis apparatus etc.

  Further, the first gap V <b> 1 is preferably polygonal in a cross section along the thickness direction of the inorganic insulating layer 17. In addition, it is desirable that a part of the second inorganic insulating particles 17b protrude in the first gap V1.

  Moreover, it is desirable that the second gap V2 has a waveform that extends while meandering. As a result, the extending direction of cracks extending from the inner wall of the through hole P to the inside of the inorganic insulating layer 17 can be efficiently changed. Further, it is desirable that the second gaps V2 have different longitudinal directions. As a result, the extending direction of cracks extending from the inner wall of the through hole P to the inside of the inorganic insulating layer 17 can be efficiently changed.

  Meanwhile, since the inorganic insulating layer 17 and the conductive layer 15 have different thermal expansion coefficients in the plane direction, when heat is applied to the interposer 4, stress is easily applied between the inorganic insulating layer 17 and the conductive layer 15.

  On the other hand, in the interposer 4 of the present embodiment, a resin layer 18 having a thickness smaller than that of the inorganic insulating layer 17 is interposed between the inorganic insulating layer 17 and the conductive layer 15. Here, since the resin layer 18 includes a resin material, the Young's modulus is smaller than that of the inorganic insulating layer 17. Therefore, since the resin layer 18 having a small thickness and a small Young's modulus is interposed between the inorganic insulating layer 17 and the conductive layer 15, the thin and easily elastically deformable resin layer 18 is deformed. The stress caused by the difference in thermal expansion coefficient between the layer 17 and the conductive layer 15 can be relieved, and peeling of the inorganic insulating layer 17 and the conductive layer 15 can be reduced. In addition, since the resin layer 18 containing the resin material has a smaller thermal expansion coefficient than the inorganic insulating layer 17, the contribution of the resin layer 18 to the thermal expansion coefficient of the base 14 is reduced, and the heat of the base 14 is reduced. The expansion coefficient can be reduced. The resin layer 18 is preferably set to have a thickness and Young's modulus smaller than those of the conductive layer 15.

Further, the through conductor 16 penetrates the inorganic insulating layer 17 and the resin layer 18 in the thickness direction, and one end thereof is electrically connected to the conductive layer 15. Therefore, since the resin layer 18 having a Young's modulus smaller than that of the inorganic insulating layer 17 is in contact with the connection portion between the through conductor 16 and the conductive layer 15 where stress tends to concentrate, the stress applied to the connection portion is reduced. The resin layer 18 can mitigate, and consequently, the disconnection between the through conductor 16 and the conductive layer 15 can be reduced.

  The through conductor 16 has a width at one end smaller than that at the other end in a cross section along the through direction. Therefore, the conductive layer 15 electrically connected to the electronic component 2 can be further miniaturized by connecting one end portion of the through conductor 16 having a small width to the conductive layer 15. Further, if the width of one end portion of the through conductor 16 is reduced, the connection reliability with the conductive layer 15 is likely to be lowered. However, in the interposer 4 of this embodiment, as described above, the through conductor 16 and the conductive layer 15 are reduced. Since the resin layer 18 is brought into contact with the connecting portion, disconnection between one end portion of the through conductor 16 and the conductive layer 15 can be favorably reduced.

  Further, the through conductor 16 has a wide portion in the resin layer 18 that is wider than the upper side and the lower side thereof. As a result, the stress at the connection portion between the through conductor 16 and the conductive layer 15 can be relaxed.

  Further, the other end of the through conductor 16 has an end surface exposed from the inorganic insulating layer 17 and is directly connected to the second bump 5b as a connection terminal. Here, since the penetration conductor 16 has a cross section along the penetration direction, the width of the other end portion is larger than that of the one end portion, so that the adhesive strength with the second bump 5b can be increased.

  Further, the other main surface of the inorganic insulating layer 16 is exposed. That is, the resin layer 18 is not formed on the other main surface of the inorganic insulating layer 16. As a result, the coefficient of thermal expansion of the base body 14 can be reduced.

  The other end of the through conductor 16 protrudes from the other main surface of the inorganic insulating layer 17. Here, when heat is applied to the interposer 4 and the wiring board 3, the thermal expansion coefficient in the planar direction between the interposer 4 and the wiring board 3 is changed along the planar direction of the inorganic insulating layer 17. When the stress is applied to the connection portion between the other end portion of the through conductor 16 and the second bump 5b, the stress can be dispersed by the protruding portion, and therefore, the other end portion of the through conductor 16 and the second bump. Connection reliability with 5b can be improved. Moreover, since this protrusion part is embedded in the 2nd bump 5b, the adhesive strength of the other end part of the penetration conductor 16 and the 2nd bump 5b can be raised by an anchor effect.

  By the way, since the through conductor 16 and the inorganic insulating layer 17 have different coefficients of thermal expansion in the thickness direction, the through conductor 16 and the inorganic insulating layer 17 are formed on the inner wall of the through hole P when heat is applied to the interposer 4. Stress is easily applied between the two.

  On the other hand, in the interposer 4 of the present embodiment, the inorganic insulating layer 17 has a convex portion 17 bp made of a part of the second inorganic insulating particles 17 b on the inner wall of the through hole P, and the convex portion 17 bp is a through conductor. 16 is covered. Since a part of the second inorganic insulating particle 17b is embedded in the through conductor 16 as described above, the adhesive strength between the through conductor 16 and the inorganic insulating layer 17 can be increased by the anchor effect. Therefore, peeling between the through conductor 16 and the inorganic insulating layer 17 on the inner wall of the through hole P can be reduced, and consequently disconnection of the through conductor 16 or the conductive layer 15 can be reduced.

In addition, the inorganic insulating layer 17 is formed with a recess C partially surrounded by the first inorganic insulating particles 17a and the second inorganic insulating particles 17b and having an opening on the inner wall of the through hole P. C is partially filled with the through conductor 16. As a result, the adhesive strength between the through conductor 16 and the inorganic insulating layer 17 can be increased by the anchor effect. The concave portion C includes a first concave portion C1 partially surrounded by a spherical curved surface and a second concave portion C2 partially surrounded by a plurality of planes having a polyhedron shape. In the cross section along the thickness direction, the first recess C1 has a circular shape and the second recess C2 has a polygonal shape.

  Thus, the mounting structure 1 described above exhibits a desired function by driving or controlling the electronic component 2 based on the power supply or signal supplied from the wiring board 3 via the interposer 4.

  Next, the manufacturing method of the mounting structure 1 mentioned above is demonstrated based on FIG.2 and FIG.3.

(Production of wiring board)
(1) As shown in FIG. 2A, the core substrate 6 is produced. Specifically, for example, it is performed as follows.

  First, for example, a plurality of resin sheets including an uncured resin and a base material are laminated, and the resin substrate 8 is produced by curing the uncured resin by heating and pressing. The uncured state is an A-stage or B-stage according to ISO 472: 1999. Next, a through hole penetrating the resin substrate 8 in the thickness direction is formed by, for example, drilling or laser processing. Next, a conductive material is deposited on the inner wall of the through hole by, for example, an electroless plating method, an electroplating method, a vapor deposition method, a CVD method, or a sputtering method to form the cylindrical through hole conductor 9. In addition, a conductive material is deposited on the upper and lower surfaces of the resin substrate 8 to form a conductive material layer. Next, the inside of the cylindrical through-hole conductor 9 is filled with a resin material or the like to form the insulator 10. Next, after a conductive material is deposited on the exposed portion of the insulator 10, the conductive layer material layer is patterned by a conventionally known photolithography technique, etching, or the like to form the wiring layer 12.

  The core substrate 6 can be manufactured as described above.

  (2) As shown in FIG. 2 (b), a pair of build-up portions 7 are formed on both sides of the core substrate 6 to fabricate the wiring substrate 5. Specifically, for example, it is performed as follows.

  First, an uncured resin is disposed on the wiring layer 12, and the insulating layer 11 is formed on the wiring layer 12 by further heating and curing the resin while heating and fluidly adhering the resin. Next, a via hole is formed in the insulating layer 11 by, for example, a YAG laser device or a carbon dioxide laser device, and at least a part of the wiring layer 12 is exposed in the via hole. Next, by using, for example, a semi-additive method, a subtractive method, or a full additive method, the via conductor 13 is formed in the via hole and the wiring layer 12 is formed on the upper surface of the insulating layer 11, thereby forming the buildup portion 7. Form. In addition, the buildup part 7 in which the insulating layer 11 is multilayered can be formed by repeating this process.

  The wiring board 3 can be produced as described above.

(Production of interposer)
(3) As shown in FIGS. 2C to 2E, a copper foil 15x with which the resin layer 18 abuts is prepared, and an inorganic insulating layer 17 is formed on the resin layer 18, whereby the substrate 14 is produced. To do. Specifically, for example, it is performed as follows.

First, as shown in FIG. 2 (c), a resin varnish is applied to one main surface of the copper foil 15x using a bar coater, a die coater, a curtain coater, and the like, and dried.
A resin layer 18 is formed thereon. The resin layer 18 formed in this step is, for example, a B stage or a C stage, and is in a desired cured state by heating. Next, an inorganic insulating sol containing first inorganic insulating particles 17 a, second inorganic insulating particles 17 b and a solvent is prepared, and the inorganic insulating sol is applied to one main surface of the resin layer 18. Next, as shown in FIGS. 2D and 2E, after drying the inorganic insulating sol and evaporating the solvent, the solid content of the inorganic insulating sol is heated to bond the first inorganic insulating particles 17a together. In addition, the inorganic insulating layer 17 is formed on the resin layer 18 by combining the first inorganic insulating particles 17a and the second inorganic insulating particles 17b.

  Here, when the inorganic insulating sol is dried and the solvent is evaporated, the first inorganic insulating particles 17a and the second inorganic insulating particles 17b are closely packed by flowing the first inorganic insulating particles 17a having a small particle diameter. Therefore, the flatness of the inorganic insulating layer 17 can be improved.

  Further, since the solvent evaporates in the gap between the second inorganic insulating particles 17b having a large particle size, a gap is formed by the amount of the solvent evaporated in the gap, so that the gap is formed between the second inorganic insulating particles 17b. A first gap V1 is formed.

  Further, since the solvent has good wettability with the second inorganic insulating particles 17b, the solvent is likely to remain at a proximity point between the second inorganic insulating particles 17b. As a result, since the first inorganic insulating particles 17a move to the proximity point as the solvent moves to the proximity point, the first void V1 is formed in a region other than the proximity point between the second inorganic insulating particles 17b. It can be formed large. In addition, by forming the first gap V1 in this way, it is possible to form a large first gap V1 in which gaps in the middle of formation are combined in a region other than the proximity point. Further, the first inorganic insulating particles 17a can be interposed between the second inorganic insulating particles 17b by moving the first inorganic insulating particles 17a to the proximity point.

  Further, when the solid content of the inorganic insulating sol is heated, the first inorganic insulating particles 17a having a small particle size and easily bonded together are bonded to each other, and the first inorganic insulating particles 17a and the second inorganic insulating particles 17b are bonded to each other. For this reason, the second inorganic insulating particles 17b having a large particle size that are difficult to bond can be bonded to each other via the first inorganic insulating particles 17a, and the inorganic insulating layer 17 can be formed.

  In addition, since the inorganic insulating layer 17 contracts due to the first inorganic insulating particles 17a being bonded to each other, an elongated second gap V2 is formed along with the contraction.

  The inorganic insulating sol includes a solid content and a solvent. The inorganic insulating sol preferably contains 5% to 50% by volume of solid content and 50% to 95% by volume of solvent. As a result, by containing 50% by volume or more of the solvent in the inorganic insulating sol, the viscosity of the inorganic insulating sol can be reduced and the flatness of the upper surface of the inorganic insulating layer 17 can be improved. Moreover, the productivity of the inorganic insulating layer 17 can be improved by increasing the solid component amount of the inorganic insulating sol by including 95% by volume or less of the inorganic insulating sol. The solid content preferably includes 20% by volume to 50% by volume of the first inorganic insulating particles 17a and 50% by volume to 80% by volume of the second inorganic insulating particles 17b.

The first inorganic insulating particles 17a having a small particle diameter are obtained by purifying a silicate compound such as a silicate compound such as a sodium silicate aqueous solution (water glass) and chemically depositing silicon oxide by a method such as hydrolysis. Can be produced. Moreover, by producing in this way, crystallization of the 1st inorganic insulating particle 17a can be suppressed and an amorphous state can be maintained. Moreover, by producing in this way, the Young's modulus of the 1st inorganic insulating particle 17a can be reduced. This is because, by producing the first inorganic insulating particles 17a under a low temperature condition, the crystal structure of silicon oxide contained in the first inorganic insulating particles 17a has a three-membered ring structure and a five-membered or more multi-membered ring. It is presumed that the structure is likely to increase. In addition, when produced in this way, the 1st inorganic insulating particle 17a may contain 1 ppm or more and 5000 ppm or less of impurities, such as sodium oxide.

  Moreover, it is desirable that the particle diameter of the first inorganic insulating particles 17a is set to 3 nm or more. As a result, the viscosity of the inorganic insulating sol can be reduced and the flatness of the upper surface of the inorganic insulating layer 17 can be improved.

  The second inorganic insulating particle 17b having a large particle size is formed by, for example, purifying a silicate compound such as an aqueous sodium silicate solution (water glass) and spraying a solution in which silicon oxide is chemically deposited in a flame to It can be manufactured by heating to 800 ° C. or higher and 1500 ° C. or lower while suppressing formation. Here, since the second inorganic insulating particles 17b can be easily produced by heating at a high temperature while reducing the formation of aggregates compared to the first inorganic insulating particles 17a, the second inorganic insulating particles 17b. Is produced by heating at a high temperature, the Young's modulus of the second inorganic insulating particles 17b can be increased more easily than that of the first inorganic insulating particles 17a. Thus, the inorganic insulating layer 17 is adjusted by adjusting the volume ratio of the first inorganic insulating particles 17a and the second inorganic insulating particles 17b using the first inorganic insulating particles 17a and the second inorganic insulating particles 17b having different Young's moduli. The Young's modulus can be adjusted.

  In addition, it is desirable that the heating time for producing the second inorganic insulating particles 17b is set to 1 second or more and 180 seconds or less. As a result, by shortening the heating time, the crystallization of the second inorganic insulating particles 17b can be suppressed and the amorphous state can be maintained even when heated to 800 ° C. or higher and 1500 ° C. or lower.

  Examples of the solvent include organic solvents such as methanol, isopropanol, n-butanol, ethylene glycol, ethylene glycol monopropyl ether, methyl ethyl ketone, methyl isobutyl ketone, xylene, propylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, or dimethylacetamide. Things can be used. Among these, it is desirable to use one containing methanol, isopropanol or propylene glycol monomethyl ether. As a result, the inorganic insulating sol can be uniformly applied and the solvent can be efficiently evaporated.

  The inorganic insulating sol can be applied using, for example, a dispenser, a bar coater, a die coater, or screen printing.

  The inorganic insulating sol is dried by, for example, heating and air drying, and the temperature is set to 20 ° C. or higher and lower than the boiling point of the solvent (the boiling point of the lowest boiling point when two or more solvents are mixed). The drying time is preferably set to 20 seconds or more and 30 minutes or less. As a result, by reducing the boiling of the solvent, the packing density of the first inorganic insulating particles 17a and the second inorganic insulating particles 17b can be increased, and the flatness of the inorganic insulating layer 17 can be increased.

The heating temperature of the inorganic insulating sol is desirably set to be not lower than the boiling point of the solvent and not higher than the crystallization start temperature of the first inorganic insulating particles 17a and the second inorganic insulating particles 17b. As a result, when the heating temperature is equal to or higher than the boiling point of the solvent, the remaining solvent can be efficiently evaporated. Further, when the heating temperature is lower than the crystallization start temperature of the first inorganic insulating particles 17a and the second inorganic insulating particles 17b, the crystallization of the first inorganic insulating particles 17a and the second inorganic insulating particles 17b is reduced. Therefore, the ratio of the amorphous state can be increased and cracks caused by the phase transition accompanying crystallization in the inorganic insulating layer 17 can be reduced. Moreover, since this heating temperature is low temperature, the increase in the Young's modulus of the 1st inorganic insulating particle 17a can be suppressed. Note that the crystallization start temperature is a temperature at which the amorphous inorganic insulating material starts to crystallize, that is, a temperature at which the volume of the crystal phase region increases. For example, the crystallization start temperature of silicon oxide is about 1300 ° C.

  Moreover, it is desirable that the heating temperature of the inorganic insulating sol is set to be lower than the thermal decomposition temperature of the resin layer 18. As a result, the inorganic insulating layer 17 can be formed while suppressing damage to the resin layer 18. The thermal decomposition temperature is a temperature at which the mass of the resin is reduced by 5% in thermogravimetry according to ISO11358: 1997. Moreover, the thermal decomposition temperature of the resin layer 18 is about 300 degreeC, for example.

  Note that the heating temperature of the inorganic insulating sol is set to 100 ° C. or more and less than 600 ° C., and more preferably 100 ° C. or more and less than 300 ° C. In addition, the heating time of the inorganic insulating sol is desirably set to, for example, not less than 0.5 hours and not more than 24 hours. The inorganic insulating sol can be heated, for example, in an air atmosphere. When the temperature is raised to 150 ° C. or higher, it is desirable to heat the inorganic insulating sol in an inert atmosphere such as vacuum or argon or a nitrogen atmosphere in order to suppress oxidation of the copper foil 15x.

  Here, the particle size of the first inorganic insulating particles 17a is desirably set to 110 nm or less. As a result, even when the heating temperature of the inorganic insulating sol is lower than the crystallization start temperature of the first inorganic insulating particles 17a and the thermal decomposition temperature of the resin layer 18, the first inorganic insulating particles 17a are firmly bonded to each other. Can be made.

  This is because the first inorganic insulating particles 17a have a particle size of 110 nm or less, and the atoms of the first inorganic insulating particles 17a, particularly the atoms on the surface, actively move. It is estimated that 1 inorganic insulating particle 17a couple | bonds firmly.

  Note that the first inorganic insulating particles 17a can be firmly bonded to each other at a lower temperature by setting the particle size of the first inorganic insulating particles 17a to be smaller. The temperature at which the first inorganic insulating particles 17a can be firmly bonded to each other is, for example, about 250 ° C. when the particle size is set to 110 nm or less, and 150 ° C. when the particle size is set to 50 nm or less. Degree.

  The particle diameter of the second inorganic insulating particles 17b is preferably set to 0.5 μm or more. As a result, since the particle diameter of the second inorganic insulating particles 17b is as large as 0.5 μm or more, a gap in which the solvent and the first inorganic insulating particles 17a are disposed between the second inorganic insulating particles 17b can be efficiently formed. The first gap V1 can be efficiently formed by evaporating the solvent in the gap.

  The solid content of the inorganic insulating sol preferably includes 20% by volume or more of the first inorganic insulating particles 17a. As a result, the amount of the first inorganic insulating particles 17a interposed between the adjacent points of the second inorganic insulating particles 17b is secured, and the area where the second inorganic insulating particles 17b are in contact with each other is reduced, whereby the inorganic insulating layer 17 The rigidity of can be increased.

  The solid content of the inorganic insulating sol desirably includes 50% by volume or more of the second inorganic insulating particles 17b. As a result, the number of the second inorganic insulating particles 17b increases, and the second inorganic insulating particles 17b are close to each other from the stage before drying, so that a skeleton is easily formed. For this reason, the formation area of the 1st space | gap V1 can be increased between this frame | skeleton.

In addition, the shape of the space | gap V is the particle size or content of the 1st inorganic insulating particle 17a or the 2nd inorganic insulating particle 17b, the kind or quantity of the solvent of an inorganic insulating sol, drying time, drying temperature, the air volume or wind speed at the time of drying. Alternatively, the gap V can be formed in a desired shape by appropriately adjusting the heating temperature or heating time after drying.

  As described above, the substrate 14 can be manufactured.

  (4) As shown in FIGS. 3A and 3B, the interposer 16 is formed by forming the through conductor 16 penetrating the base 14 in the thickness direction and forming the conductive layer 15 on one main surface of the base 14. 4 is produced. Specifically, for example, it is performed as follows.

  First, as shown in FIG. 3A, the other main surface of the substrate 14 (the main surface on which the conductive layer 15 is not formed) is irradiated with a laser beam such as a carbon dioxide laser or a YAG laser to thereby form the substrate 14. Is formed in the through hole P, and a part of the copper foil 15x disposed on one main surface of the substrate 14 is exposed in the through hole P. Next, as shown in FIG. 3 (b), by using an electroplating method, a conductive material is deposited on the exposed surface of the copper foil 15x, and the conductive material is filled in the through holes P. The through conductor 16 is formed. Next, as shown in FIG. 3C, the conductive layer 15 is formed from the copper foil 15x by using a photolithography technique, etching, or the like.

  Here, when the through hole P is formed, the other main surface of the base 14 is irradiated with laser light, and thus the through hole P having a narrow width is formed from the other main surface of the base 14 toward the one main surface. be able to. In addition, since a part of the gap V described above opens into the through hole P, the first recess C1 is formed. Further, the second recess C <b> 1 is formed when the second inorganic insulating particles 17 b are peeled off from the inner wall of the through hole P. On the other hand, since a part of the second inorganic insulating particles 17b remaining on the inner wall of the through hole P protrudes from the inner wall of the through hole P toward the inside of the through hole P, the convex portion 17bp is formed.

  Further, when the desmear process is performed in the through hole P after the laser light irradiation, the inner wall of the through hole P is etched in the resin layer 18, so that a wide portion can be formed in the through hole P in the resin layer 18. . When the wide portion is formed in this way, when the conductive material is filled in the through hole P, convection of the plating solution is likely to occur in the through hole P, and the conductive material is satisfactorily filled in the through hole P. Can do.

  In addition, when the conductive material is filled into the through hole P, the protruding portion 16p of the through conductor 16 can be formed by filling the conductive material so that it protrudes from the other main surface of the base 14. In addition, the first concave portion C1 and the second concave portion C2 are filled with a part of the through conductor 16, and the convex portion 17bp is covered with the through conductor 16.

  The interposer 4 can be produced as described above.

(Production of mounting structure 1)
(5) By mounting the interposer 4 on the wiring board 3 via the second bump 5b and mounting the electronic component 2 on the interposer 4 via the first bump 5a, the mounting shown in FIG. The structure 1 can be produced.

  In the first embodiment described above, the configuration using a resin build-up substrate as the wiring substrate has been described as an example. However, the wiring substrate may be, for example, a ceramic substrate or a resin-ceramic composite substrate. A resin coreless substrate or a single-layer printed board may be used.

  Moreover, although 1st Embodiment mentioned above demonstrated to the example the structure where the insulating layer of the buildup part of a wiring board is one layer, you may form how many insulating layers of the buildup part are formed.

In the first embodiment described above, in the step (4), a conductive material is deposited on the copper foil exposed in the through hole using the electroplating method, and the conductive material is filled in the through hole. However, for example, an electroless plating method, a sputtering method, a vapor deposition method, or the like is used to deposit a conductive material on the inner wall of the through hole, and then an electroplating method is used. Then, a conductive material may be applied to the base layer, and the conductive material may be filled into the through holes.

  Moreover, although 1st Embodiment mentioned above demonstrated the example in which the penetration conductor was electrically connected to the 1st bump via the conductive layer, the one end part of the penetration conductor was directly connected to the 1st bump. It doesn't matter.

  Moreover, although 1st Embodiment mentioned above demonstrated the example in which the other end part of the penetration conductor protruded from the other main surface of the inorganic insulating layer, the end surface of the other end part of the penetration conductor is other than the inorganic insulation layer. The main surface may be flush with the main surface, and the end surface of the other end of the through conductor may be recessed in the through hole from the other main surface of the inorganic insulating layer.

(Second Embodiment)
Next, a mounting structure including an interposer according to a second embodiment of the present invention will be described in detail based on FIG. In addition, description is abbreviate | omitted regarding the structure similar to 1st Embodiment mentioned above.

  Unlike the first embodiment, the second embodiment differs from the first embodiment in that the interposer 4A is not interposed between the wiring board and the electronic component, but is interposed between the electronic components 2A separated from each other in the thickness direction. The electronic structure 2A and the interposer 4A are alternately stacked along the thickness direction to constitute the mounting structure 1A. Therefore, by enabling the three-dimensional mounting of the electronic component 2A, the mounting structure 1A can be reduced in size and the signal transmission characteristics can be improved.

  In the mounting structure 1A, the interposer 4A has conductive layers 15A on both main surfaces of the base 14A, and the interposers 4A and the interposers 4A stacked alternately along the thickness direction via the conductive layers 15A. The electronic component 2A is electrically connected. Further, the interposer 4A located at the lowermost layer is electrically connected to an external circuit such as a mother board via the third bump 5cA connected to the conductive layer 15A formed on the lower surface of the base 14A.

  In the mounting structure 1A, the electronic components 2A and the interposers 4A that are alternately stacked in the thickness direction are electrically connected to each other as follows.

  Here, for the sake of convenience, among the interposers 4A adjacent to each other in the thickness direction, the upper one is the first interposer 4aA and the lower one is the second interposer 4bA. Of the electronic components 2A, the component mounted on the first interposer 4aA is referred to as a first electronic component 2aA, and the component mounted on the second interposer 4bA is referred to as a second electronic component 2bA. Of the conductive layer 15A, the first conductive layer 15aA is formed on one main surface of the substrate 14, and the second conductive layer 15bA is formed on the other main surface of the substrate 14.

First, as in the first embodiment, the first interposer 4aA is configured such that the conductive layer 15A connected to the upper end of the through conductor 16A is electrically connected to the first electronic component 2aA via the first bump 5aA connected to the upper surface. Connected. On the other hand, the first interposer 4aA is different from the first embodiment in that the second conductive layer 15bA connected to the lower end of the through conductor 16 is routed from the area directly below the through conductor 16A to the outside of the first electronic component 2aA mounting area. In addition, outside the first electronic component 2aA mounting region, the second conductive layer 15bA is mounted on the third conductive layer 15cA of the second interposer 4bA and the second electronic component 2bA via the fourth bump 5dA connected to the lower surface of the second conductive layer 15bA. It is electrically connected outside the area. The second interposer 4bA includes the second conductive component 15b from the outside of the second electronic component 2bA mounting area to which the third conductive layer 15cA is connected to the fourth bump 5dA.
The third conductive layer 15cA is electrically connected to the second electronic component 2bA via the fifth bump 5eA connected to the upper surface of the second electronic component 2bA. It is connected. Further, in the second interposer 4bA, the conductive layer 15A connected to the upper end of the through conductor 16A is electrically connected to the second electronic component 2bA via the first bump 5aA connected to the upper surface thereof.

  As described above, the electronic components 2A and the interposer 4A that are alternately stacked in the thickness direction are electrically connected to each other.

  The fourth bump dA and the fifth bump 5eA can be made of the same conductive material as the other bumps, and the third conductive layer 15cA can be made of the same conductive material as the other conductive layers. The formed one can be used.

  On the other hand, the second embodiment is different from the first embodiment, and the electronic component 2A is preferably a memory semiconductor element. A memory-based semiconductor element has fewer pads than a logic-based semiconductor element, and miniaturization of a circuit is mitigated. Therefore, three-dimensional mounting can be performed while maintaining electrical connection reliability.

  On the other hand, the second embodiment differs from the first embodiment in that the base 14A has resin layers 18A on both principal surfaces of the inorganic insulating layer 17A. Here, for convenience, the resin layer 18A formed on one main surface of the inorganic insulating layer 17A is referred to as a first resin layer 18aA, and the resin layer 18A formed on the other main surface of the inorganic insulating layer 17A is a second resin layer 18bA. Then, the first resin layer 18aA is interposed between the inorganic insulating layer 17A and the first conductive layer 15aA, and the second resin layer 18bA is interposed between the inorganic insulating layer 17A and the second conductive layer 15bA. ing. As a result, the first resin layer 18aA reduces the separation between the inorganic insulating layer 17A and the first conductive layer 15aA, and the second resin layer 18bA reduces the separation between the inorganic insulating layer 17A and the second conductive layer 15bA. Can do.

  The base 14A and the conductive layer 15A can be manufactured, for example, as follows.

  First, in the step (3) of the first embodiment described above, after preparing the first copper foil with which the first resin layer 18aA is in contact, and forming the inorganic insulating layer 17 on the first resin layer 18aA, The second copper foil is brought into contact with the other main surface of the inorganic insulating layer 17A via the second resin layer 18bA. Next, in the step (4) of the first embodiment described above, the first conductive layer 15aA is formed on the first resin layer 18aA, and the second resin layer 18bA is formed similarly to the first conductive layer 15aA. By forming the second conductive layer 15bA, the base body 14A can be manufactured.

(Third embodiment)
Next, a mounting structure including an interposer according to a third embodiment of the present invention will be described in detail based on FIG. In addition, description is abbreviate | omitted regarding the structure similar to 1st and 2nd embodiment mentioned above.

  As in the second embodiment, the third embodiment forms the mounting structure 1B by alternately stacking the electronic components 2B and the interposer 4B along the thickness direction. The electrical connection mode between the electronic component 2B and the interposer 4B is different from that of the second embodiment.

  Below, the electrical connection aspect of the electronic component 2B and the interposer 4B which were laminated | stacked alternately is demonstrated concretely.

As in the second embodiment, the first interposer 4aB is configured such that the conductive layer 15B connected to the upper end of the through conductor 16B is electrically connected to the first electronic component 2aB via the first bump 5aB connected to the upper surface thereof. It is connected. Here, unlike the second embodiment, the mounting structure 1 </ b> B of the present embodiment has a conductive through via conductor 19 </ b> B that penetrates in the thickness direction. Thereby, the first interposer 4aB has the second conductive layer 15bB connected to the lower end of the through conductor 16 and the upper end of the through via conductor 19B of the second electronic component 2bB via the first bump 5aB connected to the upper surface thereof. Electrically connected. In the second interposer 4bB, the conductive layer 15B connected to the upper end of the through conductor 16B is electrically connected to the lower end of the through via conductor 19B of the second electronic component 2bB via the first bump 5aB connected to the upper surface. It is connected.

  As described above, the electronic component 2B and the interposer 4B that are alternately stacked in the thickness direction are electrically connected to each other, so that the interposer 4B can connect the second conductive layer 15bB from the electronic component 2B mounting region. There is no need to draw out the electronic component 2B mounting area, and the signal transmission characteristics can be improved by downsizing the interposer 4B and shortening the wiring length.

  The through via conductor 19B described above is formed by filling a conductive material into a through via that penetrates the electronic component 2B in the thickness direction. For example, copper, silver, gold, aluminum, nickel, or the like can be used as the conductive material. it can.

  On the other hand, in the third embodiment, unlike the first and second embodiments, the base body 14B does not have the resin layer 18B, and the conductive layer 15B is in direct contact with the inorganic insulating layer 17B. As a result, the signal transmission characteristics of the conductive layer 15B can be enhanced by the inorganic insulating layer 17B having a low dielectric loss tangent.

  The base body 14B and the conductive layer 15B can be formed as follows, for example.

  First, in the step (3) of the first embodiment described above, the inorganic insulating layer 17B is directly formed on one main surface of the copper foil without forming a resin layer. Next, in the step (4) of the first embodiment described above, the first conductive layer 15aB is formed, and the second conductive layer 15bA is formed on the other main surface of the inorganic insulating layer 17B. Here, the second conductive layer 15bB is formed by depositing a conductive material on the other main surface of the inorganic insulating layer 17B by using an electroless plating method, a sputtering method, a vapor deposition method, or the like, and then performing electroplating. It can be formed by depositing a conductive material on the base layer using a method.

  Here, as for copper foil, it is desirable that one principal surface is roughened by the etching liquid which has organic acids, such as formic acid, as the main ingredients, and unevenness is formed, for example. As a result, since the inorganic insulating layer 17B is formed along the unevenness, the anchoring effect of the unevenness can increase the adhesive strength between the inorganic insulating layer 17B and the copper foil, and the unevenness on the surface of the inorganic insulating layer 17B. As a result, the adhesive strength between the inorganic insulating layer 17B and the first conductive layer 15aB can be increased.

  The present invention is not limited to the above-described embodiments, and various modifications, improvements, combinations, and the like can be made without departing from the spirit of the present invention. For example, in the mounting structure of each embodiment, the interposer may be replaced, or each member such as a base, a through conductor, or a conductive layer included in the interposer may be replaced.

DESCRIPTION OF SYMBOLS 1 Mounting structure 2 Electronic component 3 Wiring board 4 Interposer 5a 1st bump 5b 1st bump 5c 1st bump 6 Core board 7 Build-up part 8 Resin board
9 Through-hole conductor 10 Insulator 11 Insulating layer 12 Wiring layer 13 Via conductor 14 Base body 15 Conductive layer 16 Through conductor 17 Inorganic insulating layer 18 Resin layer V Void C Recess

Claims (8)

A plurality of through-holes along the thickness direction, formed with an inorganic insulating layer, a resin layer disposed on one main surface of the inorganic insulating layer, and a through conductor disposed in the through-hole,
The penetrating conductor has a wide portion located in the resin layer having a width larger than the opening of the resin layer on the inorganic insulating layer side in a cross section along the penetrating direction,
The inorganic insulating layer includes first inorganic insulating particles bonded to each other and second inorganic insulating particles having a particle size larger than that of the first inorganic insulating particles bonded to each other via the first inorganic insulating particles. Interposer characterized by having. The interposer according to claim 1, wherein
The through conductor has one end located on the resin layer side and the other end located on the inorganic insulating layer side,
An interposer characterized in that a width of the one end portion is smaller than the other end portion in a cross section along the penetrating direction. The interposer according to claim 1, wherein
The interposer is characterized in that a portion of the through conductor disposed in the inorganic insulating layer is formed in a tapered shape in which a cross-sectional area cut in a plane direction becomes smaller toward the resin layer. The interposer according to claim 1, wherein
A conductive layer disposed on one main surface of the resin layer and connected to one end of the through conductor;
The interposer characterized in that the wide portion of the penetrating conductor has a width larger than that of the one end portion of the penetrating conductor in a cross section along the penetrating direction. The interposer according to claim 1, wherein
The through conductor has one end located on the resin layer side,
The interposer is characterized in that a cross-sectional area in a planar direction of the penetrating conductor becomes smaller from the wide part toward the one end part. The interposer according to claim 1, wherein
In the inorganic insulating layer, a recess having an opening on the inner wall of the through hole is formed,
The interposer, wherein the recess is filled with a part of the through conductor. 2. The interposer according to claim 1 , wherein the through conductor has one end located on the resin layer side and the other end located on the inorganic insulating layer side, An electronic component mounted on the one end side of the through conductor of the interposer;
A mounting structure comprising: a wiring board disposed on the other end side of the through conductor of the interposer. An external circuit;
An electronic apparatus comprising: the mounting structure according to claim 7 mounted on the external circuit.

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