JP2011210795A - Laminated board, method of manufacturing the same, printed-wiring board, and semiconductor device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a laminated board for a printed-wiring board having an excellent plating burying property in a through-hole and having a superior long-term connection reliability in response to the reduction of the diameter, the thinning and aspect ratio enhancing of the printed-wiring board, and also to provide the method of manufacturing the laminated board for the printed-wiring board and a semiconductor device.SOLUTION: In the laminated board 10 for the printed-wiring board, a first insulating layer 21 containing an inorganic-fiber base material, a second insulating layer 22 on one surface side of the first insulating layer 21 and a third insulating layer 23 and a first metallic layer 12 on the other surface side of the first insulating layer 21 are laminated in the order. In the laminated board 10 for the printed-wiring board, the through-hole 41 is formed to the laminated board 10 by irradiating a laser from the surface side of the second insulating layer 22. In the laminated board 10, the through-hole 41 has the minimum diameter at a fixed depth place from the surface of the second insulating layer to an interface between the third insulating layer and the first metallic layer while the diameter of the through-hole 41 is reduced towards the fixed depth place from the surface of the second insulating layer, and the diameter of the through-hole 41 is enlarged towards the interface between the third insulating layer 23 and the first metallic layer 12 from the fixed depth place.

Description

  The present invention relates to a laminated board, a manufacturing method of the laminated board, a printed wiring board, and a semiconductor device.

  In recent years, electronic devices such as mobile phones, personal computers, videos, game machines, etc. have been used with higher density, thinner and smaller parts, and the wiring density of printed wiring boards, etc. on which they are mounted has also increased. Is required. In addition, the above printed wiring board is generally provided with a minute through hole such as a blind via hole or a through hole in a laminated board, and wiring between each layer is electrically connected by a metal deposited in the minute through hole. ing.

  However, as the density of wiring increases, through holes and blind via holes used for interlayer connection of double-sided or multilayer printed wiring boards are also required to have smaller diameters and higher aspect ratios (for example, Patent Document 1).

  Although electrical conduction can be achieved by plating the above-described blind via hole or through hole, in recent years, it is required to fill the blind via hole or through hole by plating. However, because the printed wiring board has a smaller diameter, thinner thickness, and higher aspect, the plating may not be uniformly formed in the blind via hole or through hole embedded in the plating, and bubbles may be taken into the plating for long-term connection reliability. Was not enough.

JP 2008-004800 A

  The present invention has been made in view of the above circumstances, and is a laminate and a method for manufacturing a laminate corresponding to a reduction in diameter, thickness, or increase in aspect of a printed wiring board. It is an object of the present invention to provide a printed wiring board and a semiconductor device excellent in long-term connection reliability.

The laminate according to the present invention comprises a first insulating layer containing an inorganic fiber substrate, a second insulating layer on one surface side of the first insulating layer, and a third insulating layer on the other surface side of the first insulating layer. A laminated board for a printed wiring board in which an insulating layer and a first metal layer are laminated in this order,
Through holes are formed in the laminate by irradiating a laser from the surface side of the second insulating layer,
The through hole has a minimum diameter at a predetermined depth position from the surface of the second insulating layer to the interface between the third insulating layer and the first metal layer, and the through hole is formed of the second insulating layer. The diameter is reduced from the surface of the layer toward the predetermined depth position, and the diameter is increased from the predetermined depth position toward the interface between the third insulating layer and the first metal layer.

  According to this laminated board, the through hole has a minimum diameter at a predetermined depth position from the surface of the second insulating layer to the interface between the third insulating layer and the first metal layer. The diameter is reduced from the surface of the insulating layer toward a predetermined depth position, and the diameter is increased from the predetermined depth position toward the interface between the third insulating layer and the first metal layer. As a result, the hole diameter is reduced in the through hole of the laminated plate and has a constricted shape. Therefore, when plating is formed in the through hole, first, contact between the platings grown from the wall surface of the through hole in the constricted part. Begins and embedding begins. Subsequently, the plating grows toward the surface on each side by continuing the plating. Since the diameter of the through-hole is increased in the direction in which plating grows, it is possible to provide a laminated board that can provide a printed wiring board having excellent embedding characteristics without embedding bubbles during the growth.

  The ratio (d1) / (d2) of the diameter (d2) of the through hole provided on the surface of the second insulating layer and the minimum diameter (d1) of the through hole provided at a predetermined depth is 0.5. It may be -0.9. The diameter (d2) of the surface of the second insulating layer and the diameter (d3) of the interface between the third insulating layer and the first metal layer may be (d2)> (d3). Further, when the diameter of the through hole provided in the first metal layer is (d4), (d4) <(d3) may be satisfied.

  The second or third insulating layer may contain an inorganic filler. Further, when the thickness of the third insulating layer is (t3) and the thickness of the first insulating layer is (t1), (t3) / (t1) may be 0.1-1. .

  Further, the first insulating layer is obtained by impregnating an inorganic fiber base material with an insulating resin, and the second or third insulating layer has a configuration not including an inorganic fiber base material. Also good. As a result, the processing speed of the second or third insulating layer that does not include the inorganic fiber base material by laser processing is faster than the first insulating layer that includes the inorganic fiber base material, and the second or third insulating layer expands in diameter. Can be processed.

The method for producing a laminate according to the present invention comprises a first insulating layer containing an inorganic fiber substrate, a second insulating layer on one surface side of the first insulating layer, and a second insulating layer on the other surface side of the first insulating layer. Is a method for producing a laminated board for a printed wiring board in which a third insulating layer and a first metal layer are laminated in this order,
The first metal layer having a laser resistance greater than that of the third insulating layer;
Forming a hole reaching the first metal layer by laser drilling the second insulating layer, the first insulating layer, and the third insulating layer in this order;
Continue the laser irradiation using the first metal layer as a stopper for drilling,
Drilling the first metal layer to form a through hole,
The through hole has a minimum diameter at a predetermined depth position from the surface of the second insulating layer to the interface between the third insulating layer and the first metal layer, and the through hole is formed of the second insulating layer. The diameter is reduced from the surface of the layer toward the predetermined depth position, and the diameter is increased from the predetermined depth position toward the interface between the third insulating layer and the first metal layer.

  When the laser is irradiated from the first insulating layer side, the laser that has passed through the third insulating layer reaches the first metal layer that is more laser resistant than the third insulating layer formed on the outermost layer, and the first metal layer is processed. During this time, the first metal layer continues to be irradiated with laser as a stopper. For this reason, the energy of the laser stays in the third insulating layer, the time for processing the third insulating layer is increased by the energy, and the diameter of the through hole is increased.

  Furthermore, it is possible to provide a printed wiring board by processing a circuit on the above laminate.

  Furthermore, a semiconductor device in which a semiconductor element is mounted on the printed wiring board can be provided.

  According to the present invention, there is provided a laminated board and a method for producing a laminated board corresponding to a reduction in the diameter, thickness or aspect ratio of a printed wiring board, and excellent printed embedding in a through hole and excellent long-term connection reliability. A wiring board and a semiconductor device can be provided.

It is sectional drawing of the laminated board which shows one Embodiment of this invention. It is process sectional drawing which manufactures the laminated board which shows suitable embodiment of this invention. It is process sectional drawing which manufactures the laminated board which shows suitable embodiment of this invention. It is process sectional drawing of the plating embedding which shows a prior art example.

  Hereinafter, preferred embodiments of a laminated board, a laminated board manufacturing method, a printed wiring board, and a semiconductor device according to the present invention will be described in detail. In the description of the drawings, the same reference numerals are assigned to the same elements, and duplicate descriptions are omitted.

First, with reference to FIG. 1, the outline | summary of the laminated board 10 of this embodiment is demonstrated.
The laminated board 10 of the present embodiment includes a first insulating layer 21 containing an inorganic fiber substrate, a second insulating layer 22 on one surface side of the first insulating layer 21, and the other surface side of the first insulating layer 21. Is a laminated plate 10 in which a third insulating layer 23 and a first metal layer 12 are laminated in this order. In FIG. 1, the laminated board 10 by which the 2nd metal layer 11 was laminated | stacked also on the 2nd insulating layer 22 surface side is demonstrated as embodiment.
Through holes 41 are formed in the laminate 10 by irradiating laser from the surface side of the second insulating layer 22 of the laminate 10. The through hole 41 has a minimum diameter (d1) at a predetermined depth position from the surface of the second insulating layer 22 to the interface between the third insulating layer 23 and the first metal layer 12.
The through hole 41 is reduced in diameter from the surface of the second insulating layer 22 toward a predetermined depth position, and is increased in diameter from the predetermined depth position toward the interface between the third insulating layer 23 and the first metal layer 12. ing.

Next, when the diameter of the through hole 41 provided on the surface of the second insulating layer 22 is (d2), the ratio (d1) / (d2) between the minimum diameter (d1) and (d2) is 0.5. It is preferably within the range of -0.9, more preferably 0.5-0.8. When the ratio of the diameter (d2) of the through hole 41 provided on the surface of the second insulating layer 22 to the minimum diameter (d1) is within this range, the plating embedding property of the through hole 41 in the plating embedding process is excellent. When (d1) / (d2) is smaller than 0.5, plating grown at the minimum diameter (d1) from the early stage of embedded plating comes into contact. After that, the plating grows and starts embedding. However, since the plating grows from the side wall surface for the enlarged diameter portion, the plating takes time, so if there is a non-uniform portion in the through hole 41, the plating is performed. A difference in the growth of the bubbles makes it easier to embrace bubbles. When (d1) / (d2) is larger than 0.9, the plating grows in other regions at the minimum diameter (d1) while the plating grows, and the embedding distance becomes longer. Therefore, it becomes easy to entrain bubbles during the growth.
When the diameter of the through hole 41 provided in the first metal layer 12 is (d4) and the diameter of the through hole 41 provided in the interface between the third insulating layer 23 and the first metal layer 12 is (d3), It is preferable that (d4) <(d3). The first metal layer 12 is more laser resistant than the third insulating layer 23 at the time of laser processing, and may function as a stopper at the time of drilling by laser, and the first metal layer 12 has a through hole 41 provided in the first metal layer 12. The diameter (d4) may be such that the laser penetrates the first metal layer 12. If the first metal layer 12 is penetrated even a little, the through hole 41 is formed from the third insulating layer 23 by an etching process for removing the oxide film or the like of the first or second metal layer 12 or 11 in the plating process. The first metal layer 12 protruding like an eave toward the inside is removed by etching, and the diameter (d3) of the through hole 41 provided at the interface between the third insulating layer 23 and the first metal layer 12 It becomes substantially the same diameter.

  The minimum diameter (d1) of the through hole 41 provided at a predetermined depth position is preferably provided at the interface between the first insulating layer 21 and the third insulating layer 23. Since the minimum diameter (d1) is provided at the interface between the first insulating layer 21 and the third insulating layer 23, when the through hole 41 is embedded by plating, the plating that has started to grow contacts the minimum diameter (d1) portion. Since the plating grows in the direction in which the through hole 41 expands toward the second insulating layer 22 side and the third insulating layer 23 side, the through hole 41 is filled with the plating without embedding bubbles during the growth. Is possible.

  Next, when the thickness of the third insulating layer 23 is (t3) and the thickness of the first insulating layer 21 is (t1), even if (t3) / (t1) is 0.1-1. Good. This makes it possible to form the position where the minimum diameter (d1) is formed at a position suitable for performing embedded plating.

  When the thicknesses of the first, second, and third insulating layers 21, 22, and 23 are (t1), (t2), and (t3), (t1) + (t2) + (t3) is 200 μm or less. The diameter (d2) of the through hole 41 provided on the surface of the second insulating layer 22 is 100 μm or less, and ((t1) + (t2) + (t3)) / (d2) is 0.6 or more. Even if it exists, it is applicable, and even if it is two or more. Even if the aspect ratio is large, for example, when the total thickness of the insulating layers is 1.6 mm and the diameter of the through hole 41 is 0.4 mm, the aspect ratio is 4, but the hole diameter is as large as 0.4 mm, Since the film thickness of the plating deposited on the wall surface of the hole 41 is generally 20 to 50 μm, conventionally, the plating is deposited on the wall surface of the through hole 41 without embedding the through hole 41 by plating. A method of taking electrical continuity with the metal layer formed on the substrate is employed. Therefore, even if the aspect ratio is large, there is little problem with the plating property. On the other hand, for example, when the hole diameter is 50 μm or less and the thickness of the insulating layer is 100 μm or less, the hole processing is difficult with a drill, and the hole processing is usually performed by laser processing. When laser processing is performed, the hole diameter tends to decrease in the direction in which the laser exits from the laser irradiation surface due to the nature of the processing. When the hole diameter is reduced from one surface to the other surface, when performing hole-filling through-hole plating, the plating that has started to grow first merges in the region of the metal layer on the other surface side, and then expands in diameter. The plating grows in the direction. At this time, since the distance at which the plating grows to one surface side is long, it becomes easy to entrap bubbles during the growth. This is because the plating time until filling is long, so that the deposition of plating due to the current concentration on the peripheral portion of the through hole 41 becomes excessive, and it is considered that air bubbles are easily held. On the other hand, in the present invention, since the hole diameter is narrowed in the through hole 41 of the insulating layer and has a constricted shape, when the plating is formed in the through hole 41, first, the inner wall surface of the through hole 41 is plated. Then, the platings grown from the through-hole wall surface come into contact with each other at the constricted portion, and plating embedding into the through hole 41 starts. And by continuing the plating, the plating grows toward the surface on each side. However, since the through-hole 41 is expanded in the direction in which the plating grows, air bubbles are involved. Therefore, the through hole 41 can be embedded by plating, and a printed wiring board having excellent reliability can be obtained.

  Next, the manufacturing method of a laminated board is demonstrated.

  First, the first insulating layer 21 including the inorganic fiber base material, the second insulating layer 22 and the second metal layer 11 are laminated in this order on one surface side of the first insulating layer 21. On the other surface side, a laminated plate 10 in which a third insulating layer 23 and a first metal layer 12 are laminated in this order is prepared (FIG. 2A). Although the thickness of a laminated board is not specifically limited, 20 micrometers-200 micrometers are preferable, More preferably, they are 30 micrometers-100 micrometers.

Through-holes 41 are formed in the laminated plate 10 by irradiating a laser from the surface side of the second insulating layer 22 (FIG. 2C). The hole diameter to be processed is preferably 100 μm or less, more preferably 50 μm or less. Examples of the laser include a CO ₂ laser processing machine, a UV laser processing machine, and an excimer laser processing machine, and a CO ₂ laser processing machine is preferable. The reason why a CO ₂ laser processing machine is more preferable in this patent is that it is an oscillation wavelength region in which processing of an inorganic base material is relatively easy. Furthermore, since it is an oscillation wavelength region that takes time to process the metal layer, it takes a processing time until the through hole 41 is formed, and the laser energy is retained in the third insulating layer 23 longer, so that the third insulating layer 23 becomes the first metal layer. It can be set as the shape which expands toward 12 in diameter. The laser processing conditions are preferably a pulse width of 1 to 100 μm and a reference energy of 0.5 to 9.0 mJ, more preferably a pulse width of 1 to 20 μm and a reference energy of 1.0 to 3.0 mJ. The number of shots may be appropriately determined according to the thickness of the substrate. A copper foil having a thickness of 2 μm is laminated as the second metal layer 11 on the surface of the second insulating layer 22 that is a laser incident surface. Since the processing is performed by a conformal method, the second metal layer 11 is removed by etching in accordance with the diameter of the hole to be processed in the second metal layer 11 (FIG. 2B). Since the hole provided in the second insulating layer 22 is located in the incident portion, it is easy to form the maximum diameter. The first insulating layer 21 is reached while decomposing the second insulating layer 22. Since the first insulating layer 21 includes an inorganic fiber base material, the decomposition rate by the laser is lower than that of the second insulating layer 22. Further, laser processing proceeds and the through hole 41 is directed toward the third insulating layer 23 while being reduced in diameter. The laser advances and reaches the third insulating layer 23 that does not include the inorganic fiber base material again. The laser that has reached the third insulating layer 23 reaches the second metal layer 12 that is more laser resistant than the third insulating layer. When laser irradiation is further continued using the first metal layer 12 as a stopper for drilling processing, the energy of the laser stays in the third insulating layer 23, so that the through-hole 41 whose diameter has been reduced until now is formed in the first metal layer 12. The diameter expands toward you. Next, the drilling process ends when the laser penetrates the first metal layer 12 to form the through hole 41 (FIG. 2C). The minimum diameter (d1) is likely to be formed at the interface between the first insulating layer 21 and the third insulating layer 23 where the processability by laser changes.

  The diameter (d3) of the through hole 41 provided here at the interface between the third insulating layer 23 and the first metal layer 12 is the diameter (d3) of the through hole 41 provided on the surface of the second insulating layer 22 ( Compared with d2), (d2)> (d3) may be satisfied. Since the laser processing is completed through the first metal layer 12, the diameter (d4) of the through hole 41 formed in the first metal layer 12 is provided at the interface between the third insulating layer 23 and the first metal layer 12. The hole diameter is smaller than the diameter (d3) of the through-hole 41 formed. Thus, in the method of forming the through hole 41 in the laminated plate 10 by irradiating the laser from the surface side of the second insulating layer 22 of the laminated plate 10, the through hole 41 is formed from the surface of the second insulating layer 22. And having a minimum diameter (d1) at a predetermined depth position leading to the interface between the third insulating layer 23 and the first metal layer 12, and the through hole 41 is located at a predetermined depth position from the surface of the second insulating layer 22. The laminated board 10 can be provided that is reduced in diameter toward the interface between the third insulating layer 23 and the first metal layer 12 from a predetermined depth.

As shown in FIG. 3, since the hole diameter is reduced in the through hole 41 of the laminated plate and has a constricted shape (FIG. 3A), when plating is formed in the through hole 41, first, the through hole The plating starts growing on the inner wall surface 41 (FIG. 3 (b)), and then the platings grown from the through-hole wall surface come into contact with each other at the constricted portion and the embedding of the plating begins (FIG. 3 (c)). By continuing the plating, the plating grows toward the surface on each side. In the direction in which the plating grows, the through hole 41 is enlarged in diameter, so that the through hole 41 embedded by plating is formed without embedding bubbles. Since the embedded plating does not contain bubbles, a laminated board having excellent connection reliability when used as a printed wiring board can be provided.
The diameter (d3) of the interface between the third insulating layer 23 and the first metal layer 12 can be adjusted by the thickness of the first metal layer 12. This is because the thicker the first metal layer 12 is, the longer the time until the laser penetrates, so that the amount of energy storage increases and the diameter (d3) can be increased. Furthermore, the diameter (d3) of the interface between the third insulating layer 23 and the first metal layer 12 can also be adjusted depending on the type of the insulating layer. If the material is easily decomposed by a laser, for example, an insulating material that does not include an inorganic fiber substrate and has an inorganic material filling rate of 70% or less, the diameter of the interface between the third insulating layer 23 and the first metal layer 12 (d3 ) Will grow. Therefore, it is suitable for the through hole 41 having a thick insulating layer and a small hole diameter, that is, a large aspect ratio.

Next, a method usually performed for clarifying the effect of the present invention will be described.
Usually, as shown in FIG. 4, the laminated plate 30 includes a single-layer insulating layer 20, a second metal layer 11 on one surface side of the single-layer insulating layer 20, and a second metal layer 12 on the other surface side. Are stacked. The preparation performed by the conformal method is the same as that of the present embodiment. Laser processing is performed on the second metal layer 11 on one surface side. Since the hole provided in the single-layer insulating layer 20 is located in the incident part, it forms the maximum diameter. Since it is a single-layer insulating layer, the laser processability during the processing does not change and penetrates the single-layer insulating layer 20. Since there is no insulating layer that can be easily processed even if laser processing proceeds, the single-layer insulating layer 20 is processed without expanding its diameter, and the second metal layer 11 on one surface side is changed to the first metal layer 12 on the other surface side. A through hole 40 having a reduced diameter is formed. Accordingly, the through hole 40 is formed without forming a minimum diameter at a depth position from one surface side to the other surface side of the single-layer insulating layer.
Since the through-hole 40 is unilaterally reduced in diameter from the second metal layer 11 on one surface side of the single-layer insulating layer toward the first metal layer 12 on the other surface side, growth occurs when filling through-hole plating is performed. The plating that has started has contact with the plating in the vicinity of the interface with the first metal layer 12 on the other surface side of the single-layer insulating layer forming the minimum diameter (FIG. 4B). Next, the plating grows in the direction of expanding the diameter (FIG. 4C). At this time, since the distance at which the plating grows to one surface side is long, the bubbles 43 are likely to be entrained during the growth. This is because the plating time until filling is long, so that excessive deposition of plating due to current concentration at the peripheral portion of the through-hole 40 occurs, and air bubbles are easily held.

  Next, each component of the laminated board 10 of this embodiment is demonstrated in detail.

The first insulating layer 21 includes an inorganic fiber base material. As an inorganic fiber base material, inorganic fiber base materials, such as glass fiber base materials, such as a glass fiber cloth and a glass non-woven cloth, or the fiber cloth or non-fiber cloth which contain inorganic compounds other than glass, for example are mention | raise | lifted. Among these, a glass woven fiber base material is preferable from the viewpoint of rigidity when used as a printed wiring board.
As a material which comprises resin of the 1st insulating layer 21, it is preferable that the thermosetting resin and the hardening | curing agent are included, for example. As the thermosetting resin, an epoxy resin, a cyanate resin, a phenol resin, or the like can be used alone or in combination. Although it does not specifically limit as an epoxy resin, For example, bisphenol type epoxy resins, such as a bisphenol A type epoxy resin, a bisphenol F type epoxy resin, a bisphenol AD type epoxy resin, etc. which are generally used for laminated boards, for example Novolak-type epoxy resins, cresol novolak-type epoxy resins, etc. novolak-type epoxy resins, brominated bisphenol A-type epoxy resins, brominated phenol novolac-type epoxy resins, etc. brominated epoxy resins, and heterocyclic epoxy resins such as triglycidyl isocyanate In addition, alicyclic epoxy resin, biphenyl type epoxy resin, naphthalene type epoxy resin, glycidyl ester type epoxy resin and the like can be mentioned. These can be used alone or in combination of two or more.
The cyanate resin can be obtained, for example, by reacting a halogenated cyanide compound with a phenol and prepolymerizing it by a method such as heating as necessary. Specific examples include bisphenol type cyanate resins such as novolac type cyanate resin, bisphenol A type cyanate resin, bisphenol E type cyanate resin, and tetramethylbisphenol F type cyanate resin. Among these, novolac type cyanate resin is preferable. Thereby, the heat resistance improvement by a crosslinking density increase and flame retardance, such as a resin composition, can be improved.

  Although it does not specifically limit as a hardening | curing agent, For example, it is a hardening | curing agent which has an amino group generally used for laminated boards, Comprising: Metaphenylenediamine, paraphenylenediamine, paraxylenediamine, 4,4'- Diaminodiphenylmethane, 4,4′-diaminodiphenylpropane, 4,4′-diaminodiphenyl ether, 4,4′-diaminodiphenylsulfone, 4,4′-diaminodicyclohexane, bis (4-aminophenyl) phenylmethane, 1, 5-Diaminonaphthalene, metaxylylenediamine, paraxylene naphthalene, 1,1-bis (4-aminophenyl) cyclohexane, dicyandiamide, diaminodiethyldimethylphenylmethane, and the like are used. In view of heat resistance, curability and the like, preferred curing agents are 4,4'-diaminodiphenylmethane, dicyandiamide, and diaminodiethyldimethylphenylmethane. Some of these may be used in combination.

  The first insulating layer 21 may contain an inorganic filler. For example, silicates such as talc, calcined clay, unfired clay, mica and glass, oxides such as titanium oxide, alumina, silica and fused silica, carbonates such as calcium carbonate, magnesium carbonate and hydrotalcite, aluminum hydroxide , Hydroxides such as magnesium hydroxide, calcium hydroxide, sulfates or sulfites such as barium sulfate, calcium sulfate, calcium sulfite, zinc borate, barium metaborate, aluminum borate, calcium borate, sodium borate, etc. Borate, aluminum nitride, boron nitride, silicon nitride, carbon nitride and other nitrides, strontium titanate, titanates such as barium titanate, and the like. As the inorganic filler, one of these can be used alone, or two or more can be used in combination. Among these, aluminum hydroxide and silica are particularly preferable, and fused silica (particularly spherical fused silica) is preferable in terms of excellent low thermal expansion. The shape is crushed and spherical, but in order to reduce the melt viscosity of the resin composition in order to ensure the impregnation property to the substrate, a usage method suitable for the purpose is used such as using spherical silica. The content of the inorganic filler is preferably 30 to 70 parts by weight, more preferably 40 to 60 parts by weight with respect to 100 parts by weight of the resin component.

  The average particle diameter of the inorganic filler is not particularly limited, but is preferably 0.05 to 10 μm, and particularly preferably 0.3 to 5 μm. This average particle diameter can be measured, for example, by a particle size distribution meter (manufactured by HORIBA, LA-500).

  The inorganic filler is not particularly limited, and an inorganic filler having a monodispersed average particle diameter can be used, and an inorganic filler having a polydispersed average particle diameter can be used. Furthermore, one or two or more inorganic fillers having an average particle size of monodisperse and / or polydisperse can be used in combination. The thickness of the first insulating layer 21 is preferably 20 μm to 150 μm, more preferably 30 μm to 80 μm.

  As the metal layers 11 and 12, when a metal thin film is used, a vacuum deposition method or a sputtering method is preferably used as a dry method, and an electrolytic plating method or an electroless plating method is used as a wet method. The film thickness is preferably 0.05 μm to 5 μm, more preferably 0.1 μm to 2 μm. The metal species is preferably a single metal such as nickel, chromium, cobalt, molybdenum, vanadium, tungsten or copper, or an alloy thin film thereof. Moreover, when using ultra-thin metal foil, as a metal seed | species, stainless steel, nickel, aluminum, iron, copper etc. are used, and copper is used more suitably from etching property. The thickness of the metal foil is preferably 2 μm to 12 μm.

As a material which comprises resin of the 2nd insulating layer 22, it is preferable that the thermosetting resin and the hardening | curing agent are included, for example. As the thermosetting resin, an epoxy resin, a cyanate resin, a phenol resin, or the like can be used alone or in combination. Although it does not specifically limit as an epoxy resin, For example, bisphenol type epoxy resins, such as a bisphenol A type epoxy resin, a bisphenol F type epoxy resin, a bisphenol AD type epoxy resin, etc. which are generally used for laminated boards, for example Novolak-type epoxy resins, cresol novolak-type epoxy resins, etc. novolak-type epoxy resins, brominated bisphenol A-type epoxy resins, brominated phenol novolac-type epoxy resins, etc. brominated epoxy resins, and heterocyclic epoxy resins such as triglycidyl isocyanate In addition, alicyclic epoxy resin, biphenyl type epoxy resin, naphthalene type epoxy resin, glycidyl ester type epoxy resin and the like can be mentioned. These can be used alone or in combination of two or more.
The cyanate resin can be obtained by, for example, reacting a halogenated cyanide compound with a phenol and prepolymerizing it by a method such as heating as necessary. Specific examples include bisphenol type cyanate resins such as novolac type cyanate resin, bisphenol A type cyanate resin, bisphenol E type cyanate resin, and tetramethylbisphenol F type cyanate resin. Among these, novolac type cyanate resin is preferable. Thereby, the heat resistance improvement by a crosslinking density increase and flame retardance, such as a resin composition, can be improved.

  Although it does not specifically limit as a hardening | curing agent, For example, it is a hardening | curing agent which has an amino group generally used for laminated boards, Comprising: Metaphenylenediamine, paraphenylenediamine, paraxylenediamine, 4,4'- Diaminodiphenylmethane, 4,4′-diaminodiphenylpropane, 4,4′-diaminodiphenyl ether, 4,4′-diaminodiphenylsulfone, 4,4′-diaminodicyclohexane, bis (4-aminophenyl) phenylmethane, 1, 5-Diaminonaphthalene, metaxylylenediamine, paraxylene naphthalene, 1,1-bis (4-aminophenyl) cyclohexane, dicyandiamide, diaminodiethyldimethylphenylmethane, and the like are used. In view of heat resistance, curability and the like, preferred curing agents are 4,4'-diaminodiphenylmethane, dicyandiamide, and diaminodiethyldimethylphenylmethane. Some of these may be used in combination.

  The second insulating layer 22 may contain an inorganic filler. For example, silicates such as talc, calcined clay, unfired clay, mica and glass, oxides such as titanium oxide, alumina, silica and fused silica, carbonates such as calcium carbonate, magnesium carbonate and hydrotalcite, aluminum hydroxide , Hydroxides such as magnesium hydroxide, calcium hydroxide, sulfates or sulfites such as barium sulfate, calcium sulfate, calcium sulfite, zinc borate, barium metaborate, aluminum borate, calcium borate, sodium borate, etc. Borate, aluminum nitride, boron nitride, silicon nitride, carbon nitride and other nitrides, strontium titanate, titanates such as barium titanate, and the like. As the inorganic filler, one of these can be used alone, or two or more can be used in combination. Among these, aluminum hydroxide and silica are particularly preferable, and fused silica (particularly spherical fused silica) is preferable in terms of excellent low thermal expansion. The shape is crushed and spherical, but in order to reduce the melt viscosity of the resin composition in order to ensure the impregnation property to the substrate, a usage method suitable for the purpose is used such as using spherical silica. The content of the inorganic filler is preferably 30 to 70 parts by weight, more preferably 40 to 60 parts by weight with respect to 100 parts by weight of the resin component.

  The average particle diameter of the inorganic filler is not particularly limited, but is preferably 0.05 to 10 μm, and particularly preferably 0.3 to 5 μm. This average particle diameter can be measured, for example, by a particle size distribution meter (manufactured by HORIBA, LA-500).

  The inorganic filler is not particularly limited, and an inorganic filler having a monodispersed average particle diameter can be used, and an inorganic filler having a polydispersed average particle diameter can be used. Furthermore, one or two or more inorganic fillers having an average particle size of monodisperse and / or polydisperse can be used in combination.

  As the third insulating layer 23, a material constituting the resin used for the second insulating layer 22 described above can be used. The second insulating layer 22 and the third insulating layer 23 may have the same configuration or may be different. Further, the first insulating layer 21 may have the same resin configuration or may be different except that the inorganic fiber base material is not included. Here, the first insulating layer 21 is obtained by impregnating an inorganic fiber base material with an insulating resin, and the second or third insulating layers 22 and 23 do not include the inorganic fiber base material. It may be.

  Next, a printed wiring board obtained by processing a circuit on a laminated board will be described.

  As shown in FIG. 2, first, a laminate 10 is prepared in which copper foil having a thickness of 2 μm is laminated on the front and back surfaces as first and second metal layers 11 and 12 (FIG. 2A). Next, as shown in FIG. 2B, the second metal foil 11 on the surface side of the second insulating layer 22 is removed by etching into a shape corresponding to the hole diameter. Next, the through-hole 41 is formed using a laser (FIG.2 (c)). Next, plating for filling the through holes 41 by plating is performed (FIG. 3). A desired wiring circuit was formed on the laminated plate in which the through hole 41 was filled by using a photolithography method, and then the first and second metal layers 11 and 12 were etched to form a wiring circuit. Next, an insulating coating layer was formed while leaving a part of the wiring circuit, and a metal surface treatment was performed on the opening not covered with the insulating coating layer to obtain a printed wiring board.

  Next, a semiconductor device in which a semiconductor element is mounted on a printed wiring board will be described.

  A semiconductor device in which a semiconductor element is mounted on a printed wiring board is not particularly limited. For example, a semiconductor device in which a printed wiring board and a semiconductor element are connected by a bonding wire, or a printed wiring board and a semiconductor element are connected. A flip chip type semiconductor device connected through solder bumps is exemplified. An example of a flip chip type semiconductor device will be described below.

  In a flip chip type semiconductor device, a semiconductor element having a solder bump is mounted on a printed wiring board, and the printed wiring board and the semiconductor element are connected via the solder bump. A liquid sealing resin is filled between the printed wiring board and the semiconductor element to form a semiconductor device. The solder bump is preferably made of an alloy made of tin, lead, silver, copper, bismuth or the like. The method for connecting the semiconductor element and the printed wiring board is to align the connection electrode portion on the printed wiring board and the solder bump of the semiconductor element using a flip chip bonder, etc. In addition, the solder bumps are heated to the melting point or higher by using a heating device, and the printed wiring board and the solder bumps are connected by fusion bonding. In order to improve connection reliability, a metal layer having a relatively low melting point, such as solder paste, may be formed in advance on the connection electrode portion on the printed wiring board. Prior to this joining step, the connection reliability can be improved by applying flux to the solder bumps and / or the surface layer of the connection electrode portion on the printed wiring board.

  Hereinafter, although an example and a comparative example explain the present invention, the present invention is not limited to this.

Example 1
(1) As a laminate, a glass fiber substrate having a first insulating layer of 30 μm was impregnated with an epoxy resin composition and cured to obtain a first insulating layer having a thickness of 40 μm. Next, on both sides of the first insulating layer, an epoxy resin composition that does not include an inorganic filler so that the second and third insulating layers each have a thickness of 30 μm on a copper foil having a thickness of 2 μm as a metal layer, The epoxy resin composition side was laminated on each side of the first insulating layer and laminated to form a laminate having a thickness of 100 μm.

(2) A 45 μm through-hole was formed in the laminate using a carbon dioxide laser processing machine (manufactured by Mitsubishi Electric Corporation, 605GTXIII). Next, electroless plating and electrolytic plating were performed, and the through holes 41 were filled by plating. Next, circuit formation was performed by photolithography. Next, a solder resist (PSR4000 / AUS308 manufactured by Taiyo Ink Manufacture Co., Ltd.) is formed on each surface side, an opening is provided in a circuit portion on which a semiconductor element is mounted, nickel gold plating is applied to the opening, and 50 mm × The printed wiring board was obtained by cutting into a size of 50 mm.

(3) Manufacture of Semiconductor Device A semiconductor element (TEG chip, size 15 mm × 15 mm, thickness 0.8 mm) has a solder bump formed of a eutectic of Sn / Ag composition, and a circuit protective film formed of a positive photosensitive resin (Sumitomo). Bakelite CRC-8300) was used. In assembling the semiconductor device, first, a flux material was uniformly applied to the solder bumps by a transfer method, and then mounted on the package substrate by thermocompression bonding using a flip chip bonder device. Next, after solder bumps were melt-bonded in an IR reflow furnace, a liquid sealing resin (manufactured by Sumitomo Bakelite Co., Ltd., CRP-4152S) was filled and the liquid sealing resin was cured to obtain a semiconductor device. The liquid sealing resin was cured at a temperature of 150 ° C. for 120 minutes.

  Each configuration of the printed wiring board used for the created semiconductor device is as shown in Table 1. Each of the following evaluations was performed on the semiconductor devices obtained in the examples and comparative examples. Each evaluation is shown below together with the evaluation method. The obtained results are shown in Table 1.

1. Evaluation method (1) Plating embedding property Cross section polishing of the via portion was performed at n = 30, and the embedding property in the via was confirmed. The case where there was no void, the case where there was a micro void of 3 μm or less, and the case where a void larger than 3 μm was generated were marked as x.
(2) Temperature cycle continuity test As test conditions, a temperature cycle (−60 ° C. to 150 ° C.), a holding time of 10 minutes, a temperature change time of 20 minutes, and a temperature cycle testing machine, n = 5 and 10 The conduction resistance was confirmed at each cycle, 100 cycles, and 1000 cycles.

  As is clear from Table 1, Examples 1 to 15 had good embeddability. On the other hand, in Comparative Examples 1 to 4, voids occurred during plating embedding. In Examples 1 to 15, since the through hole has a constricted shape, when plating is formed in the through hole, the plating first grows on the inner wall surface of the through hole, and then the through hole is formed in the constricted portion. The plating grown from the wall surface sticks to each other and embedding begins. And it is thought that the bubble etc. did not get involved in the growth process of plating because plating grew toward the surface of each surface side by continuing plating. On the other hand, in Comparative Examples 1 to 4, the through hole has a shape in which the diameter decreases from one surface to the other surface, and since the distance that the plating grows to one surface side is long, bubbles are generated during the growth. It is considered that the entrapment is easy and the plating time until embedding is long, so that plating deposition due to current concentration on the peripheral portion of the through-hole is excessively generated and the bubbles are easily held. As a result of the temperature cycle test in the semiconductor device, those in which bubbles were embedded in the embedded plating were defective in 10 cycles even in the cycle test.

10 Laminated plate 11 Second metal layer 12 First metal layer 20 Single layer insulating layer 21 First insulating layer 22 Second insulating layer 23 Third insulating layer 30 Laminated plate 40 Through hole 41 Through hole 43 Bubble d1 Minimum diameter d2 Second Diameter d3 of through hole provided on the surface of the insulating layer Diameter d4 of through hole provided at the interface between the third insulating layer and the metal layer Diameter t1 of through hole provided in the metal layer Thickness t2 of the first insulating layer Second insulating layer thickness t3 Third insulating layer thickness

Claims (14)

A first insulating layer containing an inorganic fiber substrate; a second insulating layer on one side of the first insulating layer; a third insulating layer and a first metal layer on the other side of the first insulating layer; Is a laminated board for printed wiring boards laminated in this order,
Through holes are formed in the laminate by irradiating a laser from the surface side of the second insulating layer,
The through hole has a minimum diameter at a predetermined depth position from the surface of the second insulating layer to the interface between the third insulating layer and the first metal layer, and the through hole is formed of the second insulating layer. The diameter is reduced from the surface of the layer toward the predetermined depth position, and the diameter is increased from the predetermined depth position toward the interface between the third insulating layer and the first metal layer. Laminated board.   When the diameter of the through hole provided on the surface of the second insulating layer is (d2) and the minimum diameter of the through hole provided at the predetermined depth position is (d1), (d1) / (d2 ) Is 0.5 to 0.9.   When the minimum diameter of the through hole provided at the predetermined depth position is (d1), (d1) is provided at the interface between the first insulating layer and the third insulating layer. Item 3. The laminated sheet according to item 1 or 2.   When the diameter of the through hole provided on the surface of the second insulating layer is (d2) and the diameter of the through hole provided at the interface between the third insulating layer and the first metal layer is (d3), The laminate according to any one of claims 1 to 3, wherein d2)> (d3). The first insulating layer is obtained by impregnating an inorganic fiber base material with an insulating resin,
The laminated board according to any one of claims 1 to 4, wherein at least one of the second and third insulating layers does not include an inorganic fiber substrate.   The laminate according to any one of claims 1 to 5, wherein at least one of the second and third insulating layers includes an inorganic filler.   The laminate according to any one of claims 4 to 6, wherein (d4) <(d3), where (d4) is a diameter of a through hole provided in the first metal layer.   The (t3) / (t1) is 0.1 to 1, where (t3) is the thickness of the third insulating layer and (t1) is the thickness of the first insulating layer. The laminated board in any one of 7.   When the thicknesses of the first, second, and third insulating layers are (t1), (t2), and (t3), respectively, (t1) + (t2) + (t3) is 200 μm or less, The diameter (d2) of the through hole provided on the surface of the second insulating layer is 100 μm or less, and ((t1) + (t2) + (t3)) / (d2) is 2 or more. The laminated board in any one. A first insulating layer containing an inorganic fiber substrate; a second insulating layer on one side of the first insulating layer; a third insulating layer and a first metal layer on the other side of the first insulating layer; Is a method of manufacturing a laminated board for a printed wiring board laminated in this order,
The first metal layer having a laser resistance greater than that of the third insulating layer;
Forming a hole reaching the first metal layer by laser drilling the second insulating layer, the first insulating layer, and the third insulating layer in this order;
Continue the laser irradiation using the first metal layer as a stopper for drilling,
Drilling the first metal layer to form a through hole,
The through hole has a minimum diameter at a predetermined depth position from the surface of the second insulating layer to the interface between the third insulating layer and the first metal layer, and the through hole is formed of the second insulating layer. The diameter is reduced from the surface of the layer toward the predetermined depth position, and the diameter is increased from the predetermined depth position toward the interface between the third insulating layer and the first metal layer. A manufacturing method of a laminated board.   The said (d1) is provided in the interface of a said 1st insulating layer and a said 3rd insulating layer when the said minimum diameter of the through-hole provided in the said predetermined depth position is set to (d1). A method for producing a laminate as described in 1.   The manufacturing method of the laminated board of Claim 10 or 11 including the process of embedding the said through-hole by electroplating.   A printed wiring board obtained by processing a circuit on the laminated board according to claim 1.   A semiconductor device comprising a semiconductor element mounted on the printed wiring board according to claim 13.

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