JP2011018727A - Circuit wiring board, and method of manufacturing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a circuit wiring board having an interlayer via with specially high reliability, and to provide a method of manufacturing the circuit wiring board.SOLUTION: The circuit wiring board includes an insulating substrate 1 having an opening part 2a formed penetrating a board surface, the interlayer conductive via 4a composed of a metal single element 4A charged in the opening part and having both end surfaces flattened along the board surface, and first and second wiring metal layers 2 and 3 having pad parts 2a and 3a provided on both surfaces of the insulating substrate and bonded to both the end surfaces of the interlayer conductive via. The metal particle single element is made of a material which is diffused on respective wiring metal layer surfaces by heating to form alloy bonds, the pad part 2a of the first wiring metal layer is alloy-bonded to one end of the interlayer conductive via 4a by heating, and the pad part 3a of the second metal alloy layer is alloy-bonded to the other end surface of the conductive via 4a by heating and pressing.

Description

  The present invention relates to a circuit wiring board and a manufacturing method thereof, and more particularly to a circuit wiring board having a highly reliable interlayer conductive via and a manufacturing method thereof.

  Recently, with the demands for smaller, lighter, and more sophisticated electronic devices, the same requirements have been increasing for printed circuit boards mounted on electronic devices. There is an increasing trend to adopt wiring boards. In addition, it is desirable that the interlayer conductive vias for conducting electrical signals between the substrates have high electrical connection reliability, and in order to keep the signal circuit in the substrate in a small space, the circuit wiring layer in the substrate is more It has been desired to make the circuit wiring layer itself a fine pattern so that the pitch can be narrowed.

  By the way, in order to form an interlayer conductive via, various techniques have been developed and put into practical use. For example, a method of forming a through hole or a blind hole in a printed board and plating a conductive metal from the inner wall of the hole to the circuit wiring layers on both sides of the board is widely adopted.

  However, the plating method requires many processing steps such as pre-treatment, post-treatment and plating layer thickness management, the space part due to through holes and blind holes remains, and electronic parts cannot be mounted on that part, There are problems such as that the form of interlayer connection such as via-on-via and pad-on-via between multilayer substrates cannot be obtained, and that the wiring layer is thicker by the plating layer, and fine patterning is restricted.

  In addition, in order to solve the problem of the plating method, a method of forming an interlayer conductive via by printing / filling a conductive paste in which fine metal particles are mixed with an epoxy resin binder into a through hole or a blind hole, For example, it has already been disclosed in Patent Documents 1 to 3 and the like.

  However, in forming a large number of interlayer conductive vias, when filling the holes with the conductive paste, conductive vias containing voids are generated, and the interlayer connection resistance value and its variation increase, resulting in reliability of interlayer connections. There is a problem that the performance is lowered.

  Next, since a method of forming interlayer conductive vias using solder balls is disclosed in Patent Document 4, this prior art will be described with reference to FIG. In this prior art, a copper foil 54 is provided via a resin composition 53 on an inner layer panel in which a copper foil pattern 52 is provided on the upper surface of an insulating substrate 51. The copper foil 54 has a small-diameter hole formed by chemical etching at a position facing a part of the copper foil pattern 52, and the resin composition 53 is blinded so as to cause an undercut under the periphery of the small-diameter hole. Hole BH is formed by chemical etching.

  Then, the solder ball is pressed to narrow the peripheral edge 54a of the small diameter hole of the copper foil 54 downward and is pushed into the blind hole BH so as to come into contact with the copper foil pattern 52. Thus, the copper foil pattern 52 and the copper foil 54 are interlayer-connected. At this time, the small-diameter hole peripheral edge 54a of the copper foil 54 is in a state having a drawing tip bent downward as shown in the figure, and the solder 55 after melting is contained in an undercut below the small-diameter hole peripheral edge 54a. And the blind hole BH is filled.

  Therefore, the melted solder 55 tends to generate notches or cracks C in the vicinity of the tip of the narrowed hole peripheral edge 54a. Particularly in a thermal shock test essential for a multilayer wiring board, it is necessary to be able to withstand thermal distortion resulting from a difference in thermal expansion coefficient between various metals and resin materials. C occurs, which causes problems such as inability to withstand mechanical strength and increase in interlayer connection resistance. Further, since a copper foil pattern is not seen on the lower surface of the insulating substrate 51, a form of interlayer connection such as via-on-via or pad-on-via between multilayer substrates is not assumed and can be obtained. Can not.

JP 2001-326465 A JP 2003-46244 A JP 2005-45187 A JP-A-8-307058

  The present invention solves the above-mentioned conventional problems, and in particular, an object thereof is to provide a circuit wiring board having a highly reliable interlayer conductive via and a manufacturing method thereof.

  According to a first aspect of the present invention, there is provided a circuit wiring board according to the present invention, comprising: an insulating substrate having an opening penetrating a plate surface; and a metal having both end surfaces filled in the opening and flattened along the plate surface An interlayer conductive via made of a single grain; and first and second wiring metal layers having pad portions respectively provided on both sides of the insulating substrate and bonded to both end faces of the interlayer conductive via; Is made of a material that diffuses to the surface of each wiring metal layer by heating to form an alloy joint and is flattened by pressurization, and the pad portion of the first wiring metal layer is alloyed to one end surface of the interlayer conductive via by heating. The pad part of the second wiring metal layer is bonded to the other end face of the conductive via by alloying by heating and pressing.

  According to a second aspect of the present invention, in the circuit wiring board according to the first aspect, the insulating substrate is made of a thermoplastic resin.

  According to a third aspect of the present invention, in the circuit wiring board according to the first aspect, the insulating substrate is made of a non-thermoplastic resin, and the first wiring metal layer is provided on one surface of the insulating substrate, The second wiring metal layer is provided on the other surface of the insulating substrate through a thermosetting resin adhesive layer.

  According to a fourth aspect of the present invention, in the circuit wiring board according to any one of the first to third aspects, the first and second wiring metal layers are made of copper, and the single metal particle is It is characterized by being composed of solder grains alone.

  The method for manufacturing a circuit wiring board of the present invention according to claim 5 includes: (A) a step of preparing a single-sided wiring substrate having a first metal layer on one surface of an insulating substrate made of a thermoplastic resin film; B) exposing the surface of the pad portion by forming an opening in the insulating substrate corresponding to the pad portion set in the first metal layer; and (C) the pad portion of the first metal layer. And (D) a material that is diffused to the surface of the first metal layer by heating to form an alloy joint and is flattened by pressurization, and is larger than the volume of the opening. A step of inserting a single metal particle for an interlayer conductive via having a volume into the opening; and (E) a surface of the first metal layer by alloy bonding with a surface of the first metal layer by heating and melting the single metal particle. Convex protruding from the opening due to tension A step of solidifying in a state in which the portion is formed, and (F) a pad portion that is heat-pressed to the other surface and alloy-bonded to the convex portion by heating and pressurizing the metal foil on the other surface of the insulating substrate. And (G) the first metal layer, and a step of forming an interlayer conductive via between the pad portions of the first and second metal layers by pressing and flattening the convex surface portion. Includes a step of forming first and second wiring metal layers by performing circuit patterning on the second metal layer after the step (F) after the step (A) or the step (F). It is characterized by.

  The method for producing a circuit wiring board of the present invention according to claim 6 includes: (A) preparing a single-sided wiring base material having a first metal layer on one surface of an insulating substrate made of a non-thermoplastic resin film; (B) A thermosetting resin adhesive layer is provided on the other surface of the insulating substrate, and openings are formed in the insulating substrate and the thermosetting resin adhesive layer corresponding to the pad portion set in the first metal layer. And (C) a step of cleaning the exposed surface of the pad portion of the first metal layer, and (D) diffusion to the surface of the first metal layer by heating. And (E) the step of inserting a single metal particle for an interlayer conductive via having a volume larger than the volume of the opening into the opening. By heating and melting the metal particles alone, the first Solidifying the surface of the pad portion of the metal layer with an alloy and forming a convex portion protruding from the opening by surface tension; and (F) overlaying the metal foil on the surface of the thermosetting resin adhesive layer. By applying heat and pressure, a second metal layer having a pad portion bonded to the surface of the thermosetting resin adhesive layer and alloy-bonded to the convex portion is formed, and the convex portion is pressed and flattened to form the first and A step of forming an interlayer conductive via between each pad portion of the second metal layer; and (G) the step of forming the first metal layer after the step (A) or step (F) and the step of forming the second metal layer. And (F) forming a first and second wiring metal layer by performing circuit patterning later.

  According to a seventh aspect of the present invention, in the method for manufacturing a circuit wiring board according to the fifth or sixth aspect, the first and second wiring metal layers are made of copper, and the single metal particles are solder particles. It consists of a single substance.

  According to the present invention, the interlayer conductive via is made of a single metal particle that can be alloy-bonded to the first and second wiring metal layers and can be flattened by pressurization, and one end surface of the metal via is a pad of the first wiring metal layer Because the alloy is joined to the part by heating and the other end surface is joined to the pad part of the second wiring metal layer by heating and pressing, the void and the interlayer connection resistance value and its variation can be greatly reduced. A remarkably reliable interlayer connection can be obtained. In addition, electronic components can be mounted on the interlayer conductive vias, via-on-vias or pad-on-vias between the multilayer substrates, and each wiring metal layer can be easily patterned.

  In particular, according to the manufacturing method of the present invention, the interlayer conductive via and the pad portion of the first metal layer can be easily and surely and satisfactorily bonded to each other by heating the pad portion after cleaning. In addition, the interlayer conductive via and the pad portion of the second metal layer have a convex surface portion of a single metal particle that is a base material of the interlayer conductive via abutted with the pad portion under heating and pressing conditions. Even if the surface of the metal foil, which is the base material of the metal layer, is oxidized, it is possible to achieve an effect such as easily and surely forming a good alloy bond with the pad portion by breaking through the oxide.

1 is a cross-sectional view showing a circuit wiring board according to a first embodiment of the present invention. It is a figure for demonstrating the manufacturing method of the circuit wiring board which concerns on 1st Embodiment of this invention, (a)-(i) is sectional drawing according to the process. It is sectional drawing which shows the circuit wiring board which concerns on 2nd Embodiment of this invention. It is a figure for demonstrating the manufacturing method of the circuit wiring board which concerns on 2nd Embodiment of this invention, (a)-(i) is sectional drawing according to the process. It is sectional drawing which shows an example of the circuit wiring board in a prior art.

  Hereinafter, a first embodiment of a circuit wiring board of the present invention will be described with reference to FIG. For example, in the insulating substrate 1 made of a film-like thermoplastic resin, a plurality of openings 1a to 1c penetrating the plate surface are formed in a portion where interlayer connection is planned. The opening is not limited to the illustrated form, and any number of shapes, shapes, and formation positions can be used. On one surface (lower surface) and the other surface (upper surface) of the insulating substrate 1, first and second wiring metal layers 2 and 3 made of, for example, copper foil are provided, respectively.

  The first wiring metal layer 2 has a plurality of first pad portions 2a to 2c in portions corresponding to the openings 1a to 1c, and the second wiring metal layer 3 similarly has a plurality of second pads. It has parts 3a-3c. Each of the openings 1a to 1c is filled with a single metal particle to form interlayer conductive vias 4a to 4c. The metal particles alone are made of a material that diffuses to the surface of each wiring metal layer by heating to form an alloy bond and is flattened by pressurization, and here, a diffusion promoting metal component that easily diffuses into copper foil For example, a single solder grain material mixed with tin or the like is used.

The interlayer conductive vias 4a to 4c have both end faces flattened along the plate surface of the insulating substrate 1,
One end surface of each of the conductive vias 4a to 4c is alloy-bonded to each of the pad portions 2a to 2c of the first wiring metal layer 2 by heating, and the other end surface of each of the conductive vias 4a to 4c is the second wiring metal layer. Each of the three pad portions 3a to 3c is alloy-bonded by heating and pressing.

  Further, since the insulating substrate 1 is a thermoplastic resin, it has an adhesive ability under heating and pressing conditions, so that the other end surfaces of the interlayer conductive vias 4 a to 4 c and the pad portions 3 a of the second wiring metal layer 3 are used. It adheres to each wiring metal layer at the time of heating and pressurizing with 3c. Each pad portion refers to a portion of the wiring metal layer that is electrically connected to the interlayer conductive via, and can also be referred to as a land portion.

  Next, a method for manufacturing the circuit wiring board according to the first embodiment will be described with reference to FIG. FIG. 2 shows the first and second pad portions 2a and 3a and the conductive via 4a in FIG. 1 and the vicinity thereof. However, these forming methods described below are the other first, This is also applied to the second pad portions 2b / 2c, 3b / 3c and the conductive vias 4b / 4c at the same time.

  First, in the step shown in FIG. 2A, a copper foil having a thickness of, for example, 10 to 12 μm is applied to one surface (lower surface) of the insulating substrate 1 made of a thermoplastic resin having a thickness of, for example, 20 to 30 μm. A single-sided wiring substrate (single-sided CCL) provided by laminating the first metal layer 2A (shown by a one-dot chain line in the figure) is prepared. Here, the first pad portion 2a of the first wiring metal layer 2 is formed by performing circuit patterning on the first metal layer 2A by a chemical etching method or the like.

  Specific examples of the thermoplastic resin for the insulating substrate include thermoplastic polyimide, liquid crystal polymer, polyphenylene sulfide (PPS), polyetheretherketone (PEEK), polytetrafluoroethylene (PTFE), polyetherimide (PEI). ), Polyarylate (PAR), polysulfone (PSF), polyethersulfone (PES), and polyamideimide (PAI).

  2B, the other surface (upper surface) of the insulating substrate 1 is covered with a mask layer 5 made of, for example, a polyimide resin film. In the step of FIG. 2C, the mask layer 5 and the insulating substrate are covered. Laser processing is performed from the upper surface side of 1 to form an opening 1a penetrating the mask layer 5 and the insulating substrate 1 so as to expose the inner surface of the first pad portion 2a.

  The shape of the opening 1a is an inverted conical shape having a maximum diameter of, for example, 100 μm so that the upper surface side has a large diameter and the lower surface side has a small diameter. This inverted conical shape is obtained by utilizing the fact that the intensity distribution at the tip of the laser beam exhibits a top hat or Gaussian distribution. Of course, the shape of the opening 1a may be a right cylindrical shape.

  In the process of FIG. 2D, the flux F is squeezed and printed using, for example, a squeegee S in order to remove and clean the native oxide on the exposed surface of the first pad portion 2a. It is applied or adhered to the exposed surface of the first pad portion 2a at the bottom of 1a.

  Then, as shown in FIG. 2E, a spherical metal particle 4A having a diameter larger than the thickness of the insulating substrate 1 is inserted into the opening 1a and placed on the flux F. Overlapping. This single metal particle 4A can be inserted by dropping into each opening using a squeezing printing technique or a guide plate having a mesh corresponding to the pad array pattern. The single metal particle 4A is made of the material of a single solder particle (solder ball) mixed with a metal component that easily diffuses into the copper foil, and the opening 1a in the thickness range of the insulating substrate 1 is formed. Have a volume greater than the volume.

  Next, the mask layer 5 is removed from the surface of the insulating substrate 1. The mask layer 5 is used to prevent surface contamination of the insulating substrate 1 through the opening 1a forming process, the surface cleaning process, and the metal grain simple substance 4A insertion process. On the other hand, the supply of the flux F can employ other methods such as spraying or dispenser. If a method of selectively and locally supplying the flux F to each opening by using a dispenser, for example, the formation of the mask layer 5 can be omitted.

  Thereafter, in the step of FIG. 2F, the molten metal 4A1 is formed by heating and melting the single metal particle 4A at a temperature of 260 ° C., for example. The molten metal 4A1 diffuses to the interface with the inner surface of the first pad portion 2a cleaned by removing the oxide with the flux F on the bottom surface side to form an alloy bond, and has low resistance or high conductivity. Sexual electrical connection is made.

  Further, the molten metal 4A1 forms a spherical convex surface portion protruding from the opening portion higher than the upper surface of the insulating substrate 1 due to surface tension on the upper surface side during the melting, and in the subsequent cooling and solidifying step, It is solidified while maintaining its shape.

  In the step of FIG. 2G, the second metal layer 3A made of a copper foil having a thickness of, for example, 10 to 12 μm for the second wiring metal layer is formed on the upper surface of the insulating substrate 1 and the solidified molten metal 4A1. In the process of FIG. 2H, for example, the insulating substrate 1, the first wiring layer 2 and the second metal layer 3A are formed for 10 to 30 minutes under the conditions of a heating temperature of 260 ° C. and a pressure of 1 to 5 Mpa. Heating and pressing is performed in a direction in which the laminate is sandwiched from both the upper and lower sides.

  At this time, since the convex surface portion of the solidified molten metal 4A1 that is thermocompression bonded to the second metal layer 3A is abutted against the second pad portion 3a of the second metal layer 3A, the base material of the second metal layer 3A is used. Even if the surface of a certain metal foil is oxidized, the oxide is pierced and a good alloy joint is easily and reliably formed with the pad portion and is flattened by pressing.

  Thus, an interlayer conductive via 4a is formed between the first and second pad portions 2a and 3a, and the first and second wiring metal layers 2 and 3 are formed on both surfaces of the insulating substrate 1 with their heat. Bonded and fixed according to the characteristics of the plastic resin.

  In the step of FIG. 2I, circuit patterning is performed on the second metal layer 3A to form the second wiring metal layer 3 (see FIG. 1) and the second pad portion 3a. Further, the formation of the first wiring metal layer 2a with respect to the first metal layer 2A may be performed in the step of FIG. 2A as described above. However, even if it is performed in the step of FIG. It does not affect the essence.

  Incidentally, in FIG. 2 (h) showing the heating and pressurizing step, the shape of the opening 1a is shown in the same shape as the steps before and after that, but the opening 1a is actually the solidified molten metal. When 4A1 is crushed, it is inflated in the direction of expanding its diameter. Since it is better that this bulge is not so large, the volume of the single metal particle 4A is such that the molten metal 4A1 does not fill the entire volume of the opening 1a, as indicated by reference numeral 6 in FIG. It is preferable to create a gap between the convex portion and the insulating substrate 1 and design the volume so as to cancel the gap 6 when the tip portion of the convex portion is crushed.

  When the opening 1a is an inverted cone, the lower half surface of the sphere of the single metal particle 4A is close to the conical surface of the opening 1a and there are few gaps. Therefore, it is easier to set the volume of the single metal particle 4A with respect to the volume of the opening 1a than in the case of the right cylindrical shape.

  According to the circuit wiring board and the manufacturing method according to the first embodiment, the interlayer conductive via and the pad portion of the first metal layer can be easily and reliably a good alloy by cleaning and heating the pad portion. Bonding is obtained. Further, the interlayer conductive via and the pad portion of the second metal layer are easily and easily configured because the convex surface portion of the single metal particle that is the base material of the interlayer conductive via is abutted against the pad portion under heating and pressing conditions. A good alloy joint can be surely obtained.

  Therefore, voids and interlayer connection resistance values and variations thereof are significantly reduced, and a highly reliable interlayer connection can be obtained. In addition, it is possible to mount electronic components on interlayer conductive vias, via-on-vias or pad-on-vias between multi-layer boards, etc., and each wiring metal layer is formed without plating, so the layer thickness Can be made thin and fine patterns can be easily obtained.

  Next, a circuit wiring board and a manufacturing method thereof according to the second embodiment of the present invention will be described with reference to FIGS. Since the second embodiment is common to the first embodiment in many respects, the same parts and configurations as those of the first embodiment are denoted by the same reference numerals, and detailed description thereof may be omitted.

  In the circuit wiring board shown in FIG. 3, the first surface (lower surface) of the insulating substrate 10 made of a non-thermoplastic resin film (for example, a polyimide resin film called Kapton manufactured by DuPont) is made of copper foil. One wiring metal layer 2 is provided, and, for example, an epoxy thermosetting resin adhesive layer 11 is bonded to the other surface.

  The overlapping insulating substrate 10 and thermosetting resin adhesive layer 11 are formed with a plurality of openings 1a to 1c penetrating therethrough, and the lower surface of the insulating substrate 10 and the upper surface of the thermosetting resin adhesive layer 11 are formed of copper. First and second wiring metal layers 2 and 3 made of foil are provided, respectively. The first wiring metal layer 2 has a plurality of first pad portions 2a to 2c, and the second wiring metal layer 3 has a plurality of second pad portions 3a to 3c.

  Interlayer conductive vias 4a-4c based on single metal grains filled in the openings 1a-1c have both end surfaces flattened along the plate surface of the insulating substrate 10, and each conductive via 4a One end surface of each of the first wiring metal layers 2 is alloy-bonded to each other by heating, and the other end surfaces of the respective conductive vias 4a to 4c are connected to the respective pad portions 3a of the second wiring metal layer 3. Alloy bonded to 3c by heat and pressure.

  Next, a method for manufacturing the circuit wiring board will be described with reference to FIG. FIG. 4 shows the first and second pad portions 2a and 3a and the conductive via 4a in FIG. 3 and the vicinity thereof, but these forming methods described below are the other first, This is also applied to the second pad portions 2b / 2c, 3b / 3c and the conductive vias 4b / 4c at the same time.

  First, in the process shown in FIG. 4A, the first surface (lower surface) of the insulating substrate 10 made of a non-thermoplastic resin film such as Kapton is formed with a copper foil having a thickness of 10 to 12 μm, for example. A single-sided wiring substrate (single-sided CCL) provided by laminating one metal layer 2A is prepared, and the other surface (upper surface) of the insulating substrate 10 is made of, for example, a thermosetting resin made of an epoxy-based thermosetting resin adhesive film. The resin adhesive layer 11 is adhered.

  4B, the upper surface of the thermosetting resin adhesive layer 11 is covered with the mask layer 5, and in the process of FIG. 4C, the mask layer 5, the thermosetting resin adhesive layer 11 and the insulating layer are insulated. Laser processing is performed on the substrate 10 from the upper surface side to form an opening 1a penetrating so as to expose an inner surface of a portion corresponding to the first pad portion 2a (see FIG. 3) of the first metal layer 2A.

  4D, in order to clean the exposed surface of the first pad portion 2a, the flux F is squeezed and the exposed surface of the first pad portion 2a is formed at the bottom of the opening 1a. Adhere to. The supply of the flux F can employ other methods such as spraying or dispenser. If a method of locally supplying the flux F to each opening 1a is employed, the formation of the mask layer 5 can be omitted.

  Then, as shown in FIG. 4 (e), spherical metal particles 4A having a diameter larger than the total thickness of the insulating substrate 10 and the resin adhesive layer 11 that overlap each other are formed in the opening 1a. And put on the flux F. The single metal particle 4A is made of the material of the single solder particle as described above in which a metal component that is easily diffused into the copper foil is mixed, and the opening 1a in the thickness range of the insulating substrate 10 and the resin adhesive layer 11 is used. Having a volume greater than

  Next, in the step of FIG. 4F, after the mask layer 5 is removed, the single metal particle 4A is heated and melted at a temperature of 260 ° C., for example, to form a single molten metal particle 4A1. The molten metal 4A1 diffuses to the interface with the inner surface of the first pad portion 2a cleaned by removing the oxide with the flux F on the bottom surface side to form an alloy bond, and has low resistance or high conductivity. Sexual electrical connection is made. Further, during the melting, the molten metal 4A1 forms a spherical convex surface portion protruding from the opening portion higher than the upper surfaces of the insulating substrate 1 and the resin adhesive layer 11 due to surface tension on the upper surface side, and thereafter cooling In the solidification step, the solidification is performed while maintaining the shape.

  In the step of FIG. 4G, the second metal layer 3A made of a copper foil having a thickness of, for example, 10 to 12 μm for the second wiring metal layer extends over the upper surfaces of the resin adhesive layer 11 and the molten metal 4A1. In the step of FIG. 4 (h), the insulating substrate 10, the resin adhesive layer 11, the first metal layer 2A, and the second metal layer are heated for 10 to 30 minutes under the conditions of a heating temperature of 260 ° C. and a pressure of 1 to 5 MPa. Heat and pressurize the 3A laminate from above and below.

  At this time, the convex portion of the molten metal 4A1 thermocompression bonded to the second metal layer 3A is abutted against the pad portion of the second metal layer 3A, and alloy bonding is obtained and flattened. In this manner, the interlayer conductive via 4a is formed between the first and second metal layers 2A and 3A, and the second metal layer 3A is bonded and fixed to the upper surface of the resin adhesive layer 11.

  In the step of FIG. 4I, the first and second metal layers 2A and 3A are subjected to circuit patterning, and the first and second pad portions 2a and 3a bonded to both end surfaces of the interlayer conductive via 4a are alloyed. Including first and second wiring metal layers 2 and 3 are formed. The first wiring metal layer 2 may be formed by patterning the first metal layer 2A in the step of FIG.

  According to the circuit wiring board and the manufacturing method according to the second embodiment, the same effect as in the first embodiment can be obtained. In the first embodiment, since the insulating substrate 1 is formed of a thermoplastic resin and there is no need to separately use an adhesive layer for bonding the wiring metal layer, the number of materials used can be reduced, and the material cost and manufacturing can be reduced. There is an advantage that the cost can be reduced and the circuit wiring board can be thinned. On the other hand, in the second embodiment, since the insulating substrate 10 is made of a non-thermoplastic resin, when a high bending rigidity is required for the circuit wiring board, it is easy to select a material that meets the requirement. There is an advantage that an inexpensive material can be selected.

  The material of the metal particle simple substance 4A is most preferably solder particles or balls. However, a copper particle simple substance (ball) coated with a solder layer is used, or tin is used as a metal component having a high diffusion coefficient with respect to the wiring metal layer. (Other metal particles (balls) such as copper, silver, bismuth, or indium can also be used. In each of the above embodiments, there are a plurality of portions such as interlayer conductive vias and openings corresponding thereto. However, the present invention includes the case where each of the above-described parts is singular.

DESCRIPTION OF SYMBOLS 1, 10 Insulating board | substrate 1a-1c Opening part 2, 3 1st, 2nd wiring metal layer 2a-2c, 3a-3c 1st, 2nd pad part 2A, 3A 1st, 2nd metal layer 4a-4c Interlayer conduction Via 4A Metal grain simple substance 4A1 Molten metal 5 Mask layer 6 Gap 11 Thermosetting resin adhesive layer

Claims (7)

  An insulating substrate formed with an opening penetrating the plate surface; an interlayer conductive via made of a single metal grain having both end surfaces filled in the opening and flattened along the plate surface; and both surfaces of the insulating substrate Each of the first and second wiring metal layers having pad portions respectively joined to both end faces of the interlayer conductive via, and the metal particles alone diffuse to the surface of each wiring metal layer by heating to form an alloy. The pad portion of the first wiring metal layer is alloy-bonded by heating to one end surface of the interlayer conductive via, and the pad portion of the second wiring metal layer is formed of the material that forms a bond and is flattened by pressurization. A circuit wiring board, wherein the other end surface of the conductive via is alloy-bonded by heating and pressing.   The circuit wiring board according to claim 1, wherein the insulating substrate is made of a thermoplastic resin.   The insulating substrate is made of a non-thermoplastic resin, the first wiring metal layer is provided on one surface of the insulating substrate, and the second wiring metal layer is disposed on the other side of the insulating substrate via a thermosetting resin adhesive layer. The circuit wiring board according to claim 1, wherein the circuit wiring board is provided on the surface of the circuit wiring board.   4. The circuit wiring board according to claim 1, wherein the first and second wiring metal layers are made of copper, and the metal particles are made of solder particles. 5. (A) preparing a single-sided wiring base material having a first metal layer on one surface of an insulating substrate made of a thermoplastic resin film;
(B) exposing the surface of the pad portion by forming an opening in the insulating substrate corresponding to the pad portion set in the first metal layer;
(C) cleaning the exposed surface of the pad portion of the first metal layer;
(D) A single metal particle for an interlayer conductive via made of a material that diffuses to the surface of the first metal layer by heating to form an alloy bond and is flattened by pressurization, and has a volume larger than the volume of the opening. Inserting into the opening;
(E) by solidifying the single metal particle by heating and solidifying in a state in which a convex surface portion protruding from the opening portion by surface tension is formed by alloy bonding with the surface of the pad portion of the first metal layer;
(F) forming a second metal layer having a pad portion that is thermocompression-bonded to the other surface and alloy-bonded to the convex surface portion by superposing and heating the metal foil on the other surface of the insulating substrate; A step of pressing and flattening the convex surface portion to form an interlayer conductive via between the pad portions of the first and second metal layers;
(G) A circuit pattern is formed on the first metal layer after the step (A) or step (F), and the second metal layer is formed on the first metal layer after the step (F). Forming a layer;
A method for manufacturing a circuit wiring board, comprising: (A) preparing a single-sided wiring substrate having a first metal layer on one surface of an insulating substrate made of a non-thermoplastic resin film;
(B) A thermosetting resin adhesive layer is provided on the other surface of the insulating substrate, and openings are formed in the insulating substrate and the thermosetting resin adhesive layer corresponding to the pad portion set in the first metal layer. Exposing the surface of the pad portion by:
(C) cleaning the exposed surface of the pad portion of the first metal layer;
(D) A single metal particle for an interlayer conductive via made of a material that diffuses to the surface of the first metal layer by heating to form an alloy bond and is flattened by pressurization, and has a volume larger than the volume of the opening. Inserting into the opening;
(E) by solidifying the single metal particle by heating and solidifying in a state in which a convex surface portion protruding from the opening portion by surface tension is formed by alloy bonding with the surface of the pad portion of the first metal layer;
(F) A second metal having a pad portion bonded to the surface of the thermosetting resin adhesive layer and alloy-bonded to the convex surface portion by superposing and heating the metal foil on the surface of the thermosetting resin adhesive layer. Forming a layer, and forming the interlayer conductive via between the pad portions of the first and second metal layers by pressing and flattening the convex surface portion;
(G) A circuit pattern is formed on the first metal layer after the step (A) or step (F), and the second metal layer is formed on the first metal layer after the step (F). Forming a layer;
A method for manufacturing a circuit wiring board, comprising:   7. The method of manufacturing a circuit wiring board according to claim 5, wherein the first and second wiring metal layers are made of copper, and the metal particles are made of solder particles.

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