JP2004259995A - Circuit board mounted with electronic component and manufacturing method thereof - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a circuit board mounted with electronic components the yield of which can be enhanced and the entire structure of which can be downsized. <P>SOLUTION: In the electronic component mount circuit board 10, through-grooves 3 whose inner face is coated with an external connection conductor film 2 are formed to end faces of a board 1 that is formed nearly rectangular; connection pads 4 to which terminals of electronic components are soldered, and connection conductors 5 for electrically connecting the connection pads 4 to the external connection conductor films 2 are formed to the principal side of the board 1; and belt-like solder dam members 6 in crossing between the through-grooves 3 and the connection pads 4 are formed on the connection conductors 5. Each of the solder dam members 6 is placed in a way that at least part of the outer circumference is tangent to or close to an upper side opening of each of the through-grooves 3. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a circuit board for mounting electronic components used by being incorporated in various electronic devices such as electronic equipment and communication equipment, and a method for manufacturing the same.
[0002]
[Prior art]
BACKGROUND ART Conventionally, electronic component mounting circuit boards have been used for surface mounting electronic component elements such as semiconductor elements, piezoelectric elements, capacitors, and filters.
[0003]
As such a conventional circuit board for mounting electronic components, for example, as shown in FIG. 4, a through-groove 52 in which an external connection conductor film 51 is attached on an inner surface is formed on an end surface of a substrate 50 having a substantially rectangular shape. On a main surface of the substrate 50, a connection pad 53 to which terminals of electronic component elements are soldered and a connection conductor 54 for electrically connecting the connection pad 53 and the external connection conductor film 51 are formed. A structure in which a band-shaped solder dam member 55 that crosses the through groove 52 and the connection pad 53 on the connection conductor 54 on the main surface is known (for example, see Patent Document 1).
[0004]
The solder dam member 55 is for preventing the molten solder from flowing toward the external connection conductor film 51 and attaching to the connection pad 53 when the terminal of the electronic component element is soldered to the connection pad 53. For example, B ₂ O ₃ , SiO ₂ , Al ₂ O ₃ , ZnO or the like, and was formed at a position separated from the upper surface opening of the through groove 52.
[0005]
When the above-mentioned conventional circuit board for mounting electronic components is manufactured, a conventionally well-known green sheet laminating method is usually employed. Specifically, first, a green sheet laminate in a semi-cured state having a substantially rectangular substrate region is prepared, and a through hole serving as a through groove 52 is formed in an outer peripheral portion of the substrate region. A conductor paste for the external connection conductor film 51 is printed and formed on the inner surface of the hole, and a conductor paste for the connection pads 53 and the connection conductors 54 is printed in a predetermined pattern on the inside of the substrate area and dried. The glass paste for the solder dam member 55 is printed on the conductor paste for 54 so as to cross between the through hole and the application area of the conductor paste for the connection pad 53, and then the green sheet laminate is pressed from the upper surface with pressure. Is applied and press-formed, and finally, it is baked to obtain a circuit board for mounting electronic components.
[0006]
Then, the operation of mounting the electronic component element on the electronic component mounting circuit board obtained by the above-described manufacturing process is performed by first placing the electronic component element at a predetermined position on the upper surface of the electronic component mounting circuit board with the terminal thereof connected to the connection pad 53. This is carried out by placing the semiconductor chip so as to be brought into contact with the solder, and then heating and melting the solder to solder the connection pad 53 to the terminal of the electronic component element. At this time, even if the molten solder flows to the external connection conductor film 51 side, the solder is damped by the solder dam member 55, thereby preventing the adhesion of the solder to the external connection conductor film 51.
[0007]
The electronic component mounting circuit board on which the electronic component elements are mounted is divided for each substrate area, and then placed on an external wiring board such as a mother board, and the pads of the external wiring board and the electronic component mounting circuit board are mounted. The external connection conductor film 51 is mounted on an external wiring board by soldering.
[0008]
[Patent Document 1]
JP-A-10-75041 (FIGS. 1 and 4)
[0009]
[Problems to be solved by the invention]
By the way, according to the conventional electronic component mounting circuit board described above, since the glass paste for the solder dam member 55 is disposed at a position separated from the upper opening of the through groove 52, the green sheet laminate is formed. When a large pressure is applied in the thickness direction of the green sheet laminate during press molding, the green sheet laminate is greatly deformed in the plane direction by the pressure. At this time, since the conductor paste for the external connection conductor film 51 attached to the through holes of the green sheet laminate has been dried, cracks may occur in the conductor paste due to the above-described deformation, and cracks may occur. If it is large, it has a drawback that the production yield of the circuit board for mounting electronic components is greatly reduced due to electric disconnection or the like.
[0010]
Further, in the above-mentioned conventional electronic component mounting circuit board, the solder dam member 55 is disposed at a position separated from the through groove 52, and a useless space is formed between the solder dam member and the through groove. Therefore, the space for mounting the electronic component elements and arranging the surface wiring such as the connection pads 53 and the connection conductors 54 is limited, and the size of the electronic component mounting circuit board is not reduced. There was also.
[0011]
The present invention has been devised in view of the above-mentioned drawbacks, and an object of the present invention is to provide a circuit board for mounting electronic components and a method for manufacturing the same, which can improve the manufacturing yield and can be used for miniaturization of the entire structure. To provide.
[0012]
[Means for Solving the Problems]
The circuit board for mounting electronic components of the present invention is characterized in that a through-groove extending in the thickness direction of the substrate and having an external connection conductor film attached to the inner surface thereof is formed on an end surface of the substantially rectangular substrate, and the main surface of the substrate is formed. Forming a connection pad to which terminals of the electronic component element are soldered and a connection conductor for electrically connecting the connection pad and an external connection conductor film, and forming the connection conductor on the main surface of the substrate on the connection conductor. An electronic component mounting circuit board formed by forming a band-shaped solder dam member crossing between a through groove and a connection pad, wherein at least a part of an outer periphery of the solder dam member contacts an upper surface side opening of the through groove. Or are arranged close to each other.
[0013]
Further, in the circuit board for mounting electronic components according to the present invention, the solder dam member is arranged along an upper surface side opening of the through groove.
[0014]
Further, the circuit board for mounting electronic components of the present invention is characterized in that the solder dam member has a cutout window at a position in contact with or close to the upper surface opening of the through groove, to expose the connection conductor. It is assumed that.
[0015]
Still further, in the method of manufacturing a circuit board for mounting electronic components according to the present invention, a conductor paste for an external connection conductor film is applied to an inner surface of a green sheet laminate having a substantially rectangular substrate region, at an outer peripheral portion of the substrate region. Conductive paste for connecting pads to be soldered to the terminals of the electronic component element, and conductive paste for connecting conductors connecting the connecting pads to the external connecting conductive film, inside the substrate region, Applying, and in the substrate region of the green sheet laminate, on the conductive paste for the connection terminal, at least a part of the outer periphery is in contact with or close to the upper surface side opening of the through hole, and A step of applying a glass paste for a solder dam member in a strip shape so as to cross a region between the through-hole and the application area of the connection pad conductive paste, and a thickness of the green sheet laminate Press-forming by applying pressure in the direction, a step of impregnating the organic paste in the glass paste into the green sheet laminate and the conductor paste for the external connection conductor film located immediately below the glass paste for the solder dam member, Baking the green sheet laminate, the conductive paste and the glass paste.
[0016]
According to the present invention, the solder dam member is disposed so that at least a part of the outer periphery thereof is in contact with the upper surface side opening of the through groove. When the green paste is applied so as to be in contact with or close to the upper surface opening of the through hole and press-mold the green sheet, the organic solvent contained in the glass paste is disposed immediately below the green paste. The conductor paste for the connection conductor film is impregnated, whereby moderate toughness is imparted to the green sheet laminate around the through hole and the conductor paste for the external connection conductor film. Therefore, even if the green sheet laminate is greatly deformed in the plane direction due to the pressure applied to the green sheet laminate, the conductor paste for the external connection conductor film itself is flexibly deformed, thereby effectively generating cracks. The yield of the circuit board for mounting electronic components can be improved.
[0017]
According to the present invention, at least a part of the outer periphery of the solder dam member is in contact with or close to the opening on the upper surface side of the through groove. In this case, the useless space is reduced, and the entire structure of the electronic component mounting circuit board can be reduced accordingly.
[0018]
Further, according to the present invention, by disposing the solder dam member along the upper surface opening of the through groove, there is almost no useless space between the solder dam member and the through groove, and electronic component mounting In addition to being able to further reduce the overall structure of the circuit board for use, the organic solvent contained in the glass paste is evenly impregnated into the entire conductor paste for the external connection conductor film disposed immediately below the glass paste. Therefore, when the green sheet laminate is press-formed, the entire conductive paste for the external connection conductor film deforms more flexibly following the deformation of the green sheet laminate, and cracks are generated. The prevention can be more reliably achieved.
[0019]
Still further, according to the present invention, the solder dam member is formed with a cutout window that exposes the connection conductor at a position that is in contact with or close to the upper surface opening of the through groove, so that electronic component mounting can be performed. When connecting the external connection conductor film of the circuit board for soldering to the pad of the external wiring board such as a motherboard, if the amount of solder is controlled so that a part of the solder crawls up to the inside of the cutout window, Inspection of the connection can be easily performed only by visually checking whether or not the solder is attached, and the work of confirming the connection state after mounting the electronic component mounting circuit board is reliable and simple. It becomes.
[0020]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.
[0021]
FIG. 1 is a schematic perspective view of an electronic component mounting circuit board according to an embodiment of the present invention, and FIG. 2 is an enlarged perspective view of a main part of FIG. 1. The electronic component mounting circuit board 10 shown in FIG. A through groove 3 having an external connection conductor film 2 attached to the inner surface is formed on an end surface of the rectangular substrate 1, and a connection pad 4 to which a terminal of an electronic component element is solder-bonded is formed on the main surface of the substrate 1. A connection conductor 5 for electrically connecting the connection pad 4 and the external connection conductor film 2 is formed, and a band-shaped solder dam member traversing the through groove 3-the connection pad 4 on the connection conductor 5 on the main surface of the substrate 1. 6 is formed.
[0022]
The substrate 1 has, for example, a multilayer structure in which a plurality of insulating layers are stacked, and functions as a supporting base material for supporting an electronic component element on its main surface. Surface wiring such as connection pads 4 and connection conductors 5 formed on the main surface, internal wiring (not shown) interposed between insulating layers, via hole conductors (not shown) formed between layers, and the like. Forming an electric circuit.
[0023]
The insulating layer forming the substrate 1 has a thickness of, for example, 20 to 300 μm, and is preferably made of a glass-ceramic material that can be fired at a relatively low temperature of 800 to 1050 ° C. Used for As a ceramic component of the glass-ceramic material, for example, an insulating ceramic material such as cristobalite, quartz, corundum (α-alumina), mullite, cordierite, or the like is used.
As the glass component, for example, B ₂ O ₃ , SiO ₂ , Ai ₂ O ₃ , ZnO, a glass frit containing an alkaline earth metal oxide, or the like is used.
[0024]
Further, a plurality of through grooves 3 are formed on the end face of the substrate 1. The through-groove 3 is formed, for example, in a semi-cylindrical shape. When the external connection conductor film 2 is applied to the inner surface of the through-groove 3, the electronic component mounting circuit board 10 is mounted on an external wiring board such as a motherboard. And a conductive adhesive such as solder to be joined to the external connection conductor film 2.
[0025]
The external connection conductor film 2 adhered to the inner surface of the through groove 3 is made of a conductive material mainly containing an Ag alloy such as Ag, Ag-Pd, Ag-Pt, etc. When mounted on an external wiring board, the circuit board 10 functions as a terminal for electrically and mechanically connecting the circuit board 10 for mounting electronic components to pads of the external wiring board with a conductive adhesive such as solder.
[0026]
On the main surface of the substrate 1, a pair of connection pads 4 corresponding to the terminal electrodes of the electronic component element in a one-to-one manner are formed in a mounting region of the electronic component element. The connection conductor 5 is formed so as to electrically connect the connection pad 4 on the side close to the external connection conductor film 2 and the external connection conductor film 2 on the inner surface of the through groove 3.
[0027]
The connection pads 4 and the connection conductors 5 are made of a conductive material mainly composed of an Ag alloy such as Ag, Ag-Pd, Ag-Pt, etc., and the connection pads 4 are used to solder the terminals of the electronic component element to the substrate 1. One of the pads is electrically connected to the external connection conductor film 2 on the inner surface of the through groove via the connection conductor 5 described above.
[0028]
Furthermore, a band-shaped solder dam member 6 is formed on the main surface of the substrate 1 so as to cross between the through-groove 3 and the connection pad 4 on the connection conductor 5, and the solder dam member 6 has at least a part thereof. Are arranged so as to be in contact with or close to the upper surface side opening of the through groove 3.
[0029]
As described in the section of the prior art, the solder dam member 6 tends to cause the molten solder to flow toward the external connection conductor film 2 when the terminals of the electronic component elements are soldered to the electronic component mounting circuit board 10. At this time, this is to prevent the solder from adhering to the external connection conductor film 2 by damming it.
[0030]
The solder dam member 6 has a part of its outer periphery in contact with or close to the opening on the upper surface side of the through groove 3, and is used for manufacturing the electronic component mounting circuit board 10. Is applied so as to be in contact with or close to the opening on the upper surface side of the through-groove 3, and when this is press-molded, the organic solvent contained in the glass paste is placed under the glass paste. The conductor paste for the connection conductor film is impregnated, whereby moderate toughness is imparted to the green sheet laminate around the through hole and the conductor paste for the external connection conductor film. Therefore, even if the green sheet laminate for forming the substrate 1 greatly changes in the plane direction due to the pressure due to the press molding, the conductor paste for the external connection conductor film itself is flexibly deformed and cracks are generated. Generation can be effectively prevented, thereby improving the production yield of the circuit board 10 for mounting electronic components.
[0031]
The distance d from the upper surface opening of the through groove 3 to the outer periphery of the solder dam member 6 is 0 to 150 μm (when d = 0 μm, the state in which the upper surface opening of the through groove 3 and the outer periphery of the solder dam member 6 are in contact with each other). Is set in the range.
[0032]
If the distance between the upper surface opening of the through groove 3 and the outer periphery of the solder dam member 6 exceeds 150 μm, it is included in the glass paste for the solder dam member when manufacturing the electronic component mounting circuit board 10. The organic solvent used may not sufficiently penetrate into the conductor paste for the external connection conductor film, and as a result, the conductor paste for the external connection conductor film may not be imparted with appropriate toughness and cracks may occur. There is. Therefore, it is desirable to set the closest distance from the upper surface opening of the through groove 3 to the outer periphery of the solder dam member 6 within 150 μm.
[0033]
Further, by making the solder dam member 6 and the through groove 3 contact or close to each other as described above, a useless space between the solder dam member 6 and the through groove 3 is reduced, and the wasteful space is reduced accordingly. There is also an advantage that the overall structure of the electronic component mounting circuit board 10 can be reduced in size.
[0034]
The material of the solder dam member 6 is selected in consideration of compatibility with the glass-ceramic material forming the substrate 1. For example, a glass capable of firing the solder dam member 6 at a relatively low temperature of 800 to 1050C. When formed of a material, B used for the substrate 1 ₂ O ₃ , SiO ₂ , Ai ₂ O ₃ , ZnO, glass materials such as glass frit containing alkaline earth metal oxides are preferably used.
[0035]
Thus, the above-described electronic component mounting circuit board 10 has the electronic component element mounted on the upper surface thereof at a predetermined position such that its terminals are in contact with the connection pads 4 via solder, and the solder is heated and melted. Then, the connection pad 4 and the terminal of the electronic component element are soldered to form a predetermined electronic component. At this time, even if the molten solder tries to flow to the external connection conductor film 2 side, it is effective that the molten solder is satisfactorily dammed by the solder dam member 6 and the solder tends to adhere to the external connection conductor film 2. Is prevented.
[0036]
In the case where the electronic component mounting circuit board 10 on which the electronic component elements are mounted is mounted on an external wiring board such as a motherboard to form an electronic device, the electronic component mounting circuit board 10 is mounted on one main surface of the external wiring board. The external connection conductor film 2 of the electronic component mounting circuit board 10 is soldered to pads of the external wiring board.
[0037]
Next, a method of manufacturing the above-described electronic component mounting circuit board 10 will be described.
[0038]
In the present embodiment, an example will be described in which the electronic component mounting circuit board 10 is manufactured by a “multiple-cavity” method of simultaneously obtaining a plurality of electronic component mounting circuit boards 10 from a large green sheet laminate. .
[0039]
(Step 1)
First, a through-hole in which a conductor paste for an external connection conductor film is formed on the inner surface is formed on the outer periphery of the substrate region of the green sheet laminate having a substantially rectangular substrate region, and inside the substrate region, A conductor paste for a connection pad to be soldered to a terminal of an electronic component element and a conductor paste for a connection conductor for connecting the connection pad to the external connection conductor film are applied.
[0040]
The ceramic green sheet constituting the green sheet laminate is formed by half-molding a slurry obtained by uniformly mixing a glass raw material powder, a frit of a low-melting glass component, an organic binder, and an organic solvent to a predetermined thickness by a conventionally known doctor blade method. A green sheet laminate is formed by laminating a predetermined number of such ceramic green sheets by setting them in a cured state.
[0041]
The substrate region of such a green sheet laminate has a shape corresponding to the circuit board 10 for mounting electronic components, and a plurality of such substrate regions are arranged in a matrix on the main surface of the green sheet laminate. ing.
[0042]
When such a ceramic green sheet is made of a glass-ceramic material that can be fired at a relatively low temperature of, for example, 800 to 1050 ° C., the composition ratio of the ceramic component is, for example, 10 to 60 wt%, and the glass component is, for example, 40 to 50%. It is set to 90 wt%, and as the ceramic raw material powder, for example, cristobalite, quartz, corundum (α-alumina), mullite, cordierite pulverized to an average particle size of 0.5 to 6.0 μm, preferably 0.5 to 2.0 μm Insulating ceramic material such as MgTiO ₃ , CaTiO ₃ , BaTiO ₃ , TiO ₃ And magnetic ceramic materials such as Ni-Zn ferrite and Mn-Zn ferrite. ₂ O ₃ , SiO ₂ , Ai ₂ O ₃ , ZnO, a glass frit containing an alkaline earth metal oxide, or the like is used. The glass frit used here precipitates a crystal phase of cordierite, mullite, anorthite, serdian, spinel, garnite, willemite, dolomite, petalite or a substituted derivative thereof or a crystal phase having a spinel structure by firing. Any glass may be used.
[0043]
Further, the organic binder is preferably one having excellent thermal decomposability so that it can be eliminated in a relatively low-temperature and short-time firing step. In addition, in consideration of the wettability of ceramic powder and glass components with frit, acrylic binder is preferably used. It is preferable to use an ethylenically unsaturated compound having a carboxyl group or an alcoholic hydroxyl group such as an acid or methacrylic acid-based polymer.
[0044]
In addition, as the organic solvent, for example, 2.2.4-trimethyl-1.3-pentadiol monoisoventate or the like is used.
[0045]
The through-hole is formed by punching and drilling a green sheet laminate so as to straddle a boundary part that divides each substrate region, and a conductor such as an Ag-based conductor paste is formed on an inner surface of such a through-hole. The paste is printed and applied and dried. The external connection conductor film 2 is formed on the inner surface of the through-groove by firing this conductor paste in Step 4 described later.
[0046]
In addition, a conductor paste for forming connection pads, connection conductors, internal wiring, and the like in a single-layer state before forming the laminate is formed on the main surface of each ceramic green sheet constituting the green sheet laminate. The conductor paste for connection pads and connection conductors is printed and applied on the uppermost ceramic green sheet, and the conductor paste for internal wiring is printed and applied on other ceramic green sheets except for the uppermost layer, and dried. It is processed.
[0047]
As the conductive paste used here, for example, Ag, Ag-Pd, Ag-Pt or other Ag-based powder, borosilicate-based low-melting glass frit, organic binder such as ethylcellulose, or a mixture obtained by homogeneously mixing an organic solvent is used. Can be
[0048]
(Step 2)
Next, in the substrate region of the green sheet laminate, on the conductor paste for the connection conductor, at least a part of the outer periphery is in contact with or close to the upper surface side opening of the through hole, and the through hole -A glass paste for the solder dam member is applied in a strip shape so as to cross between the application areas of the connection pad conductor paste.
[0049]
In order to approximate the sintering behavior of the glass paste for the solder dam member to the sintering behavior of the green sheet laminate, the same glass material in the ceramic green sheet constituting the green sheet laminate is used. A low-melting glass material is preferably used. ₂ O ₃ , SiO ₂ , Ai ₂ O ₃ , ZnO, a glass frit such as an alkaline earth metal oxide, an organic binder, and an organic solvent are homogeneously mixed.
[0050]
The material composition ratio of such a glass paste is, for example, 60 to 70 wt% of glass frit and 1 to 5 wt% of organic binder in consideration of impregnating an organic solvent into the green sheet laminate and the external connection conductor film. % And the organic solvent are set in the range of 25 to 30 wt%.
[0051]
In addition, as an organic solvent used for the above-mentioned glass paste, for example, 2.2.4-trimethyl-1.3-pentadiol monoisoventate or the like is used.
[0052]
The glass paste as described above is printed and applied on the main surface of the green sheet laminate by screen printing or the like, which is conventionally known, so that at least a part of the outer periphery is in contact with or close to the upper opening of the through hole. .
[0053]
(Step 3)
Next, while applying pressure in the thickness direction of the green sheet laminate to press-mold, the glass paste is applied to the green sheet laminate and the conductor paste for the external connection conductor film located immediately below the glass paste for the solder dam member. Impregnate the organic solvent inside.
[0054]
At this time, the organic solvent contained in the glass paste is impregnated into the conductor paste for the external connection conductor film disposed immediately therebelow, whereby the green sheet laminate and the external connection conductor film around the through hole are formed. Moderate toughness is imparted to the conductive paste. Therefore, even if the green sheet laminate is greatly deformed in the plane direction due to the pressure applied to the green sheet laminate, the conductor paste for the external connection conductor film itself is flexibly deformed, thereby effectively generating cracks. And the production yield of the circuit board for mounting electronic components can be improved.
[0055]
Further, after such a pressing step, it is preferable to form a scribe line (divided groove) for dividing each substrate region on the main surface of the green sheet laminate with a cutter or the like.
[0056]
(Step 4)
Next, the green sheet laminate, the conductive paste and the glass paste are fired.
[0057]
The baking process includes a debinding step and a sintering step. In the first debinding step, the green sheet laminate, the conductor paste such as the external connection conductor film 2 and the connection pad 4 and the glass paste for the solder dam member are used. Burn out organic components contained in. This binder removal step is performed in a temperature range of, for example, 500 to 600 ° C.
[0058]
The subsequent sintering process is performed in an oxidizing atmosphere or an air atmosphere so that the peak temperature reaches 800 to 1050 ° C., whereby the glass component of the glass-ceramic green sheet laminate and the glass paste for the solder dam member are removed. At the same time, the glass component in the green sheet laminate is uniformly dispersed at the grain boundaries of the ceramic powder to impart appropriate strength to the green sheet laminate, and the external connection conductor film 2 and the conductor for surface wiring are simultaneously crystallized. The metal powder, Ag powder and the like contained in the paste are grown.
[0059]
(Step 5)
Finally, the green sheet laminate is divided into individual substrate regions along the scribe line, whereby a plurality of electronic component mounting circuit boards 10 are obtained at the same time.
[0060]
When mounting electronic component elements on the electronic component mounting circuit board 10 obtained by the above-described manufacturing process, first, the electronic component elements are placed at predetermined positions on the upper surface of each electronic component mounting circuit board 10, and the terminals of the electronic component elements are connected to the connection pads. Then, the connection pad 4 and the terminal of the electronic component element are soldered by heating and melting the solder so that the connection pad 4 and the terminal of the electronic component element are soldered. At this time, even if the molten solder flows to the external connection conductor film 2 side, it is blocked by the solder dam member 6, thereby preventing the solder from adhering to the external connection conductor film 2.
[0061]
The electronic component mounting circuit board 10 on which the electronic component elements are mounted is further mounted on an external wiring board such as a motherboard, and the pads on the external wiring board and the external connection conductor film of the electronic component mounting circuit board 10 are mounted. 2 is mounted on an external wiring board by soldering.
[0062]
The present invention is not limited to the above-described embodiment, and various changes and improvements can be made without departing from the gist of the present invention.
[0063]
In the above-described embodiment, the solder dam member 6 is arranged such that at least a part of the outer periphery is in contact with the upper opening of the through groove 3. However, as shown in FIG. It may be arranged along the opening on the upper surface side of the through groove 3. In this case, since there is almost no useless space between the solder dam member 6 and the through groove 3, the overall structure of the electronic component mounting circuit board 10 can be further reduced in size, and in addition, the glass paste contains Since the organic solvent contained is evenly impregnated into the entire conductor paste for the external connection conductor film disposed immediately below the glass paste, when the green sheet laminate is press-formed, the conductor for the external connection conductor film is used. The paste as a whole is more flexibly deformed following the deformation of the green sheet laminate, and the occurrence of cracks can be more reliably prevented.
[0064]
Further, in the above-described embodiment, as shown in FIG. 3, if a cutout window 7 for exposing the connection conductor 5 is formed at a position in contact with or close to the upper surface opening of the through groove 3, the electronic component can be formed. When soldering the external connection conductor film 2 of the mounting circuit board 10 to pads of an external wiring board such as a motherboard, the amount of solder is controlled so that a part of the solder crawls up to the inside of the cutout window 7. Accordingly, the inspection for connection can be easily performed only by visually checking whether or not solder is attached to this portion, and the connection state confirmation work performed after mounting the circuit board 10 for mounting electronic components. Will be reliable and simple.
[0065]
Further, in the above-described embodiment, the shape of the through groove 3 is formed in a semi-cylindrical shape, and at least a part of the outer periphery of the solder dam member 6 is disposed so as to be in contact with the through groove 3. Needless to say, the shape of the solder dam member 6 may be arranged such that a part of the outer periphery of the solder dam member 6 is in contact with or close to such a through groove 3.
[0066]
Furthermore, in the above embodiment, after the individual electronic component mounting circuit boards 10 are divided for each substrate region from the large green sheet laminate, the electronic component elements are mounted on the electronic component mounting circuit boards 10. Alternatively, the electronic component elements may be mounted on the respective substrate areas of the large-sized green sheet laminate, and then the individual electronic component mounting circuit boards 10 may be divided.
[0067]
Furthermore, in the above-described embodiment, after forming the green sheet laminate by laminating the ceramic green sheets, the through holes are formed in the green sheet laminate by punching. Before laminating the ceramic green sheets, through holes may be formed in the individual ceramic green sheets, and then the ceramic green sheets may be laminated to form a green sheet laminate.
[0068]
【The invention's effect】
According to the present invention, at least a portion of the outer periphery of the solder dam member is in contact with or close to the upper surface side opening of the through groove, so that in manufacturing the electronic component mounting circuit board, When the glass paste for the solder dam member is applied so as to be in contact with the upper opening of the through-hole and the green sheet is press-formed, the organic solvent contained in the glass paste is disposed immediately below the external connection. The conductive paste for the conductive film is impregnated, whereby moderate toughness is imparted to the green sheet laminate around the through hole and the conductive paste for the external connection conductive film. Therefore, even if the green sheet laminate is greatly deformed in the plane direction due to the pressure applied to the green sheet laminate, the conductor paste for the external connection conductor film itself is flexibly deformed, thereby effectively generating cracks. The yield of the circuit board for mounting electronic components can be improved.
[0069]
According to the present invention, at least a part of the outer periphery of the solder dam member is in contact with or close to the opening on the upper surface side of the through groove. In this case, the useless space is reduced, and the entire structure of the electronic component mounting circuit board can be reduced accordingly.
[0070]
Further, according to the present invention, by disposing the solder dam member along the upper surface opening of the through groove, there is almost no useless space between the solder dam member and the through groove, and electronic component mounting In addition to being able to further reduce the overall structure of the circuit board for use, the organic solvent contained in the glass paste is evenly impregnated into the entire conductor paste for the external connection conductor film disposed immediately below the glass paste. Therefore, when the green sheet laminate is press-formed, the entire conductive paste for the external connection conductor film deforms more flexibly following the deformation of the green sheet laminate, and cracks are generated. The prevention can be more reliably achieved.
[0071]
Still further, according to the present invention, a notch window for exposing the connection conductor is formed at a position in contact with or close to the upper surface opening of the through groove of the solder dam member, so that electronic component mounting is achieved. When soldering the external connection conductor film of the circuit board for soldering to the pad of an external wiring board such as a motherboard, if the amount of solder is controlled so that a part of the solder climbs up to the inside of the cutout window, Inspection of the connection can be easily performed only by visually checking whether or not the solder is attached, and the work of confirming the connection state after mounting the electronic component mounting circuit board is reliable and simple. It becomes.
[Brief description of the drawings]
FIG. 1 is a schematic perspective view of an electronic component mounting circuit board according to an embodiment of the present invention.
FIG. 2 is an enlarged perspective view of a main part of the circuit board for mounting electronic components of FIG. 1;
FIG. 3 is an enlarged perspective view of a main part of a circuit board for mounting electronic components according to another embodiment of the present invention.
FIG. 4 is a schematic perspective view of a conventional circuit board for mounting electronic components.
[Explanation of symbols]
1 ... substrate
2 ... External connection conductor film
3 ... through-groove
4: Connection pad
5 Connection conductor
6 ... Solder dam member
7 ... cutout window
10 Circuit board for mounting electronic components

Claims (4)

Terminals of electronic component elements are solder-bonded to an end surface of the substantially rectangular substrate, a through groove extending in the thickness direction of the substrate, and having an inner surface covered with an external connection conductor film, to a main surface of the substrate. And a connection conductor for electrically connecting the connection pad and the external connection conductor film, and a strip-shaped solder crossing the connection groove and the connection pad on the connection conductor on the main surface of the substrate. A circuit board for mounting electronic components formed with a dam member,
The electronic component mounting circuit board according to claim 1, wherein at least a part of the outer periphery of the solder dam member is in contact with or close to an upper surface side opening of the through groove. 2. The circuit board for mounting electronic components according to claim 1, wherein the solder dam member is arranged along an upper opening of the through groove. 3. 3. The electronic component according to claim 1, wherein the solder dam member has a cutout window that exposes the connection conductor at a position in contact with or close to an upper surface opening of the through groove. 4. Circuit board for mounting. A through-hole in which a conductive paste for an external connection conductive film is formed on an inner surface is formed in an outer peripheral portion of the substrate region of the green sheet laminate having a substantially rectangular substrate region, and an electronic component is formed inside the substrate region. A step of applying a conductor paste for a connection pad to be solder-bonded to a terminal of the element and a conductor paste for a connection conductor for connecting the connection pad to the external connection conductor film,
In the substrate region of the green sheet laminate, at least a part of the outer periphery is in contact with or close to the upper surface side opening of the through hole on the conductor paste for the connection terminal, and the through hole-connection pad A step of applying a glass paste for the solder dam member in a strip shape so as to cross between the application regions of the conductor paste,
While applying pressure in the thickness direction of the green sheet laminate and press-forming, the organic paste in the glass paste is applied to the green sheet laminate and the external connection conductor film conductor paste located immediately below the solder dam member glass paste. A step of impregnating the solvent,
Baking the green sheet laminate, the conductive paste and the glass paste.

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