JP4903320B2 - Manufacturing method of wiring board with electronic element - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve the problem that, when the size of a wiring board with electronic element is reduced and the packaging density of the board is increased, the thermal shock resistance and connection reliability of the board have not been improved. SOLUTION: The wiring board 5 with electronic element is provided with an insulating layer 1a, wiring conductors 2 arranged on the layer 1a, and through conductors 3b electrically connected to the conductors 2 and the electrodes 4a of an electronic element 4. The board 5 is also provided with the electronic element 4 the electrodes 4a of which are electrically connected to the through conductors 3b. The electrodes 4a of the element 4 are formed in projecting states and, at the same time, the front end sections of the electrodes 4a are embedded in the conductors 3b. Since the electrodes 4a of the element 4 are firmly connected to the conductors 3b by anchoring effects, no by peeling disconnection caused occurs between the element 4 and wiring conductors 2 even when the wiring board 5 is subjected to thermal shock tests and reflow soldering. Consequently, the thermal shock resistance and connection reliability of the wiring board 5 are improved.

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a wiring board used for various AV equipment, home appliances, communication equipment, computers and electronic equipment such as peripheral equipment thereof, and more particularly to a wiring board with electronic elements in which an electronic element is mounted on a part of the wiring board. About.
[0002]
[Prior art]
Conventionally, a wiring board with electronic elements has a plurality of wiring conductors formed inside and on the surface of an insulating layer made of a ceramic material such as alumina or an organic resin material such as glass epoxy resin, and a semiconductor element or capacitor is formed on the surface. It is formed by mounting and attaching an electronic element such as a resistance element and connecting these electrodes to each wiring conductor.
[0003]
However, in recent years, electronic devices have been required to be small, thin, and lightweight as represented by mobile communication devices, and wiring boards with electronic elements mounted on such electronic devices are also small and high density. There is a need to make it easier. For this reason, a small electronic element to be mounted on the wiring board with an electronic element is adopted, and it is necessary to reduce the mounting area as much as possible.
[0004]
Recently, in order to reduce the number of electronic elements mounted on the surface of the wiring board with electronic elements and reduce the size of the wiring board with electronic elements, it has also been proposed to mount electronic elements inside the wiring board.
[0005]
[Problems to be solved by the invention]
However, in recent years, more and more miniaturization and higher density have been demanded, and the wiring conductor of the wiring board with electronic elements has been miniaturized, and the electronic elements mounted on or inside the wiring board with electronic elements have also been downsized. When the thermal shock test, which is a high-temperature and low-temperature cycle test, is performed when the area of the connection portion between the electronic element and the wiring conductor is reduced, both of them are large due to the difference in thermal expansion coefficient between the electrode of the electronic element and the insulating layer There has been a problem that stress is generated and the electronic element and the wiring conductor are separated and disconnected.
[0006]
Further, in the high-temperature reflow process when mounting the electronic element on the wiring board, the position of the electronic element is shifted due to the difference between the thermal expansion of the insulating layer and the thermal expansion of the electronic element. There was also a problem that the connection between the electrode and the wiring conductor could not be performed normally.
[0007]
The present invention has been devised in view of the problems of the prior art, and an object of the present invention is to provide a small and lightweight wiring board with electronic elements that is excellent in thermal shock resistance and connection reliability.
[0010]
[Means for Solving the Problems]
According to the present invention, there is provided a method of manufacturing a wiring board with an electronic element incorporating an electronic element, the steps of preparing first, second and third insulating layers, and forming a through hole in the second insulating layer, after filling the conductive paste, the exposed portion of the conductive paste positioned on one principal surface of the second insulating layer, wherein the wiring conductor to be connected to the exposed portion of the conductive paste second A step of transferring to one main surface of the insulating layer, a step of forming a through hole in the third insulating layer, the one main surface of the second insulating layer being formed on the first insulating layer, and a step of forming the second insulating layer on the second insulating layer. The first to third insulating layers are sequentially stacked so that the other main surface is in contact with the third insulating layer, and an electronic element having a protruding electrode is accommodated in the through hole of the third insulating layer. and while mounted on the other main surface of the second insulating layer, the insulating layer distal end portion of the electrode Burying from the other main surface to the conductive paste, it is characterized in that it comprises a step of curing the conductive paste.
[0014]
DETAILED DESCRIPTION OF THE INVENTION
Next, the wiring board with electronic elements of the present invention will be described in detail with reference to the accompanying drawings.
[0015]
FIG. 1 is a cross-sectional view showing a reference example of the wiring board with electronic elements of the present invention. FIG. 2 shows a reference example when the electronic elements are mounted inside the wiring board in the wiring board with electronic elements of the present invention. FIG. In these figures, 1a is an insulating layer, 1 is an insulating substrate composed of a plurality of insulating layers 1a, 2 is a wiring conductor, 3a is a through hole, 3b is a through conductor, 4 is an electronic element such as a capacitor, The wiring board 5 with an electronic element of the present invention is configured. FIG. 1 shows an example in which two layers of insulating layers 1a are stacked, and FIG. 2 shows a case where the wiring substrate 5 with electronic elements is manufactured by stacking five layers of insulating layers 1a. In addition, in the reference example of FIG. 2, a through hole 6 that houses the electronic element 4 is provided in a part of the insulating layer 1 a (two layers in this example), and the electronic element 4 is embedded in the through hole 6. ing. Further, a wiring conductor 2 is disposed on the surface of the insulating layer 1a, and is electrically connected to the electrode 4a of the electronic element 4 through the through conductor 3b. Moreover, in the wiring board 5 with an electronic element of the present invention, the electrode 4a of the electronic element 4 has a protruding shape and is embedded in the through conductor 3b.
[0016]
The insulating layer 1a functions as a support for the wiring conductor 2 and the electronic element 4, and is made of a ceramic material such as alumina or glass ceramic, or an epoxy resin, a bismaleimide triazine resin, a thermosetting polyphenylene ether resin, or a liquid crystal polymer resin. In particular, from the viewpoints of weight reduction, miniaturization, high-frequency characteristics, and processability, it is preferably made of an organic resin material such as a thermosetting polyphenylene ether resin or a liquid crystal polymer resin.
[0017]
When the insulating layer 1a is made of an organic resin material, a coupling agent such as silane or titanate for improving mechanical strength, an antioxidant for improving thermal stability, or light resistance is improved. Light stabilizers such as ultraviolet absorbers, halogen or phosphoric acid flame retardants to improve flame retardancy, flame retardant aids such as antimony compounds, zinc borate, barium metaborate, zirconium oxide Agents, higher fatty acids to improve lubricity, lubricants such as higher fatty acid esters, higher fatty acid metal salts, fluorocarbon surfactants, aluminum oxide for adjusting thermal expansion coefficient and / or improving mechanical strength・ Silicon oxide, titanium oxide, barium oxide, strontium oxide, zirconium oxide, calcium oxide, zeolite, silicon nitride, aluminum nitride, Weaving fillers such as silicon hydride, potassium titanate, barium titanate, strontium titanate, calcium titanate, aluminum borate, barium stannate, barium zirconate, strontium zirconate, or fibrous glass Glass cloth or the like may be included.
[0018]
Such an insulating layer 1a is, for example, an inorganic insulating powder such as aluminum oxide, silicon nitride, aluminum nitride, silicon carbide, titanium oxide, barium oxide, strontium oxide, zirconium oxide, calcium oxide having a particle size of about 0.1 to 15 μm, Add thermosetting resin such as epoxy resin, phenol resin, polyimide resin, bismaleimide resin, thermosetting polyphenylene ether resin, or thermoplastic resin such as liquid crystal polyester, polyphenylene ether resin and solvent, plasticizer, dispersant, etc. The obtained paste is made into a sheet by adopting a sheet molding method such as a conventionally known doctor blade method, or a glass cloth glass in which a fibrous glass is woven into a cloth is immersed in the above paste so as to be vertical. Forming a precursor sheet to become the insulating layer 1a by pulling and drying After that, it is obtained by cutting into a desired size.
[0019]
When the electronic element 4 to be mounted is formed inside the insulating substrate 1 as shown in a sectional view in FIG. 2, a through hole 6 for accommodating the electronic element 4 is formed in a part of the insulating layer 1a. It is installed. Such a through-hole 6 is formed in the insulating layer 1a in accordance with the size and shape of the electronic element 4 by performing drilling processing by a conventionally known laser processing method or punching processing by a punching method.
[0020]
In addition, the wiring conductor 2 is deposited on at least one of the upper and lower surfaces of the insulating layer 1a. The wiring conductor 2 has a thickness of about 2 to 30 μm and is made of a highly conductive metal foil such as copper or gold, or a conductive paste such as copper, silver, tungsten, or molybdenum, and is mounted on the wiring board 5 with an electronic element. It has a function of electrically connecting the electronic element 4 to an external electric circuit (not shown).
[0021]
Such a wiring conductor 2 is formed by depositing a metal foil made of copper, for example, formed by patterning by a subtractive method using a known photoresist on a precursor sheet to be an insulating layer 1a by a transfer method or the like. Alternatively, a conductive paste obtained by adding a metal powder such as copper, silver, tungsten, or molybdenum to a thermosetting resin or thermoplastic resin and a solvent, a plasticizer, a dispersant, or the like using a conventionally known screen printing method. It is formed by printing.
[0022]
Furthermore, a through conductor 3b having a diameter of about 20 to 150 μm is formed in the insulating layer 1a. The through conductor 3b has a function of electrically connecting the wiring conductors 2 positioned above and below the insulating layer 1a and the wiring conductor 2 and the electrode 4a of the electronic element 4. In such a through conductor 3a, a through hole 3a is formed by drilling the insulating layer 1a with a laser, and a conductive paste made of copper, silver, gold, solder, or the like is conventionally known in the through hole 3a. It is formed by embedding by the screen printing method.
[0023]
Each electrode 4a of the electronic element 4 to be mounted is electrically connected to a part of the through conductor 3b. In the wiring board 5 with an electronic element of the present invention, the electrode 4a of the electronic element 4 has a protruding shape. In addition, the tip is embedded in the through conductor 3b. This is also important.
[0024]
According to the wiring board 5 with an electronic element of the present invention, the electrode 4a of the electronic element 4 is formed in a protruding shape, and its tip is embedded in the through conductor 3b. Even when a thermal shock test, which is a high-temperature and low-temperature cycle test, is firmly connected to 3b by the anchor effect, the electronic element 4 and the wiring conductor 2 are not separated and disconnected. Further, even when a difference in thermal expansion occurs between the electronic element 4 and the insulating layer 1a during high-temperature reflow when the electronic element 4 is mounted, the protruding electrode 4a is firmly connected to the through conductor 3b by the anchor effect. Therefore, the positional shift of the electronic element 4 can be suppressed, and as a result, the wiring board 5 with an electronic element having excellent connection reliability with good connection between the electrode 4a of the electronic element 4 and the wiring conductor 2 can be obtained. it can.
[0025]
The protruding electrode 4a of the electronic element 4 is formed by repeatedly printing a conductive paste such as copper, silver, tungsten, or molybdenum on the surface of the electronic element 4 by using a conventionally well-known screen printing method. The
[0026]
The protrusion shape of the electrode 4a of the electronic element 4 may be circular, elliptical, or polygonal in cross section in the direction parallel to the insulating layer 1a. However, from the viewpoint of relaxing the stress at the connection portion, circular or elliptical. It is preferable that In addition, the cross-sectional area of the electrode 4a in the direction parallel to the insulating layer 1a is determined from the connection with the electronic element 4 from the viewpoint of preventing air entrapment when the protruding electrode 4a is embedded in the through conductor 3b. Also, it is preferable that the tip portion is smaller. Further, the height T of the electrode 4a is preferably in the range of 0.1t to 0.5t, where t is the thickness of the insulating layer 1a. If the height T of the electrode 4a is less than 0.1t, a sufficient anchor effect is obtained. As a result, the connection part tends to be disconnected in the thermal shock test, and when it exceeds 0.5 t, the conductive paste is used when the wiring board 5 with electronic elements is finally pressed and heated to form a multilayer. May protrude significantly from the through-holes 3a, and there is a risk of causing poor adhesion between the insulating layers 1a. Therefore, the height T of the electrode 4 a is preferably 0.1 t to 0.5 t with respect to the thickness t of the insulating layer 1.
[0027]
Further, the diameter of the cross section of the protruding electrode 4a in the direction parallel to the insulating layer 1a is slightly smaller than the diameter of the through hole 6, and may be determined by the required position accuracy. Further, the connection between the electronic element 4 and the through conductor 3b is performed by inserting the protruding electrode 4a of the electronic element 4 into the uncured through conductor 3b, and then heating to cure the through conductor 3b. Such a wiring board 5 with an electronic element is manufactured by the following method. First, a through hole 3a is formed at a desired position of the precursor sheet to be the insulating layer 1a by laser drilling or the like, and the through hole 3a is filled with a conductive paste made of copper or the like using, for example, a screen printing method. After forming the through conductors 3b, a patterned metal foil of copper, for example, is hot-pressed at a temperature of 100 to 200 ° C. and a pressure of 0.5 to 10 MPa for 10 minutes to 1 hour and transferred to the insulating layer 1a. Thus, the wiring conductor 2 and the through conductor 3b are electrically connected to obtain the first insulating layer 1a in which the wiring conductor 2 and the through conductor 3b are formed. At this time, the through conductor 3b is preferably left in an uncured state that is not completely cured. Next, apart from the insulating layer 1a, a through hole 3a is formed by laser drilling or the like at a desired position of the precursor sheet to be the insulating layer 1a, and a conductive paste made of copper or the like is formed in the through hole 3a. After the through conductor 3b is formed by using, for example, a screen printing method, the electronic element 4 is mounted so that the protruding electrode 4a is embedded in the through conductor 3b. 2 insulating layers 1a are obtained. Then, the first and second insulating layers 1a are laminated so that the wiring conductor 2 of the first insulating layer 1a and the through conductor 3b of the second insulating layer 1a overlap each other. The precursor sheet and the conductive paste are completely cured by hot pressing at 300 ° C. and a pressure of 0.5 to 10 MPa for 30 minutes to 24 hours.
[0028]
When the electronic element 4 is formed inside the wiring board, a first through hole 6 slightly larger than the electronic element 4 is formed in a region corresponding to the electronic element 4 on the upper surface of the second insulating layer 1a. The insulating layer 1a is laminated and then hot-pressed under the same conditions as described above. Further, the wiring conductor 2 may be formed on the second insulating layer 1 on which the electronic element 4 is mounted. In this case, by setting the through conductor 3b to an uncured state that is not completely cured, the protruding electrode 4a of the electronic element 4 can be easily embedded in the through conductor 3b.
[0029]
Thus, according to the wiring board 5 with an electronic element of the present invention, the electrode 4a of the electronic element 4 is formed in a protruding shape, and its tip is embedded in the through conductor 3b. Even when a thermal shock test, which is a high-temperature and low-temperature cycle test, is firmly connected to the conductor 3b by an anchor effect, the electronic element 4 and the wiring conductor 2 are not separated and disconnected. Further, even when a difference in thermal expansion occurs between the electronic element 4 and the insulating layer 1a during high-temperature reflow when mounting the electronic element 4, the protruding electrode 4a is embedded in the through conductor 3b. The positional deviation can be suppressed, and as a result, the wiring board 5 with an electronic element having excellent connection reliability in which the connection between the electrode 4a of the electronic element 4 and the wiring conductor 2 can be obtained.
[0030]
Next, the manufacturing method of the wiring board with an electronic element of this invention is demonstrated in detail based on FIG. FIG. 3 is a cross-sectional view for each process for manufacturing the wiring board with electronic elements of FIG.
[0031]
First, as shown in a cross-sectional view in FIG. 3A, an uncured precursor sheet to be an insulating layer 11a is prepared, and this precursor sheet is penetrated into a desired portion by a diameter of about 20 to 150 μm by laser processing. Hole 13a is drilled.
[0032]
Such an uncured precursor sheet to be the insulating layer 11a is made of ceramic materials such as alumina and glass ceramics, or organic resin materials such as epoxy resin, bismaleimide triazine resin, thermosetting polyphenylene ether resin, and liquid crystal polymer resin. When the insulating layer 11a is made of an organic resin material, a coupling agent such as silane or titanate for improving mechanical strength, an antioxidant for improving thermal stability, or light resistance is improved. Light stabilizers such as ultraviolet absorbers, halogen or phosphoric acid flame retardants to improve flame retardancy, flame retardant aids such as antimony compounds, zinc borate, barium metaborate, zirconium oxide Lubricants, higher fatty acid esters, higher fatty acid esters, higher fatty acid metal salts, fluorocarbon surfactants, etc. to improve lubricity Aluminum oxide, silicon oxide, titanium oxide, titanium oxide, barium oxide, strontium oxide, zirconium oxide, calcium oxide, zeolite, silicon nitride, aluminum nitride, silicon carbide for adjusting the thermal expansion coefficient and / or improving the mechanical strength・ Potassium titanate ・ Barium titanate ・ Strontium titanate ・ Calcium titanate ・ Aluminum borate ・ Barium stannate ・ Barium zirconate ・ Strontium zirconate Etc. may be included.
[0033]
Such a precursor sheet is manufactured by the following method when, for example, a composite material of a thermosetting resin and an inorganic insulating powder is used as an insulating material. First, a mixture is obtained by adding a thermosetting resin to the above-mentioned inorganic insulating powder together with a solvent so that the amount of the inorganic insulating powder is 20 to 80% by volume, and this mixture is used in a kneader (kneader), three rolls, or the like. Mix by means to make a paste. Then, this paste is formed into a sheet by using a sheet forming method such as a rolling method, an extrusion method, an injection method, or a doctor blade method, and then dried by heating to a temperature at which the thermosetting resin is not completely cured. A precursor sheet to be the insulating layer 11a is manufactured. The paste is preferably prepared by adding a solvent such as toluene, butyl acetate, methyl ethyl ketone, methanol, methyl cellosolve acetate, isopropyl alcohol, methyl isobutyl ketone, dimethylformamide to a composite material of thermosetting resin and inorganic insulating powder. The fluid having a predetermined viscosity is preferably 100 to 3000 poise depending on the sheet molding method.
[0034]
Next, as shown in the cross-sectional view of FIG. 3B, the through-hole 13a is filled with a conductive paste made of copper, silver, gold, solder, or the like by using a conventionally known screen printing method or the like. A conductor 13b is formed.
[0035]
Next, as shown in a cross-sectional view in FIG. 3C, a wiring conductor 12 to be attached to the front and back surfaces of the precursor sheet is prepared. Then, as shown in a cross-sectional view in FIG. 3D, the wiring conductor 12 is superimposed and transferred onto the front and back surfaces of the precursor sheet so that the necessary wiring conductor 12 and the through conductor 13a are electrically connected. To do.
[0036]
In this embodiment, the wiring conductor 12 is formed by a transfer method. Such a wiring conductor 12 is formed by the method described below. First, an electrolytic metal foil having a thickness of 1 to 35 μm made of one or more alloys selected from copper, gold, silver, aluminum, etc., which is manufactured on the surface of the support 20 such as a release sheet by plating. And a resist layer is formed on the surface so as to be a mirror image pattern of a desired wiring pattern, and then a wiring conductor 12 having a mirror image of a predetermined wiring pattern is formed by etching and resist removal. Next, the deposition of the wiring conductor 12 on the front and back surfaces of the precursor sheet is performed by superimposing the support 20 on which the wiring conductor 12 is formed on the front and back surfaces of the precursor sheet, and then the pressure is 0.5 to 10 MPa. After pressurizing and heating at a temperature of 60 to 150 ° C., the support 20 is peeled off, so that the wiring conductor 12 is attached to the precursor sheet as shown in the sectional view of FIG. At this time, it is important that the through conductor 13b is in an uncured state that is not completely cured.
[0037]
As the support 20, known materials such as polyethylene terephthalate, polyethylene naphthalate, polyimide, polyphenylene sulfide, vinyl chloride, and polypropylene can be used. The thickness of the support is suitably 10-100 μm, preferably 25-50 μm. If the thickness of the support is less than 10 μm, the wiring conductor 12 formed by deformation or bending of the support is likely to break, and if the thickness exceeds 100 μm, the support becomes inflexible and the support from the precursor sheet Twenty peels tend to be difficult. Further, in order to form the electrolytic metal foil on the surface of the support 20, a known adhesive such as acrylic, rubber, silicon or epoxy may be used.
[0038]
Then, as shown in a sectional view in FIG. 3 (f), a plurality of precursor sheets manufactured through the steps (a) to (f) and an electronic element 14 having a protruding electrode 14a are prepared. Next, the tip of the electrode 14a is embedded in the through conductor 13b made of a conductive paste and a precursor sheet is laminated, and the temperature is 150 to 300 ° C. and the pressure is 0.5 to 10 MPa. The precursor sheet and the conductive paste are completely cured by pressing to complete the electronic element-equipped wiring board 15 of the present invention shown in a sectional view in FIG.
[0039]
Note that FIG. 3 shows an example in which the electronic element 14 is formed inside the wiring board. However, the through hole 16 that accommodates the electronic element 14 has an electronic element on the precursor sheet before the precursor sheet is laminated. It is only necessary to drill the part 14 to be accommodated by a laser method or a punching method.
[0040]
As described above, according to the method for manufacturing the wiring board 15 with an electronic element of the present invention, when the protruding electrode 14a of the electronic element 14 is embedded in the conductive paste forming the through conductor 13b, the conductive paste Since it is in an uncured state, it can be embedded easily, and by curing the conductive paste, the electrode 14a of the electronic element 14 can be firmly fixed to the through conductor 13b made of the conductive paste. Even when an impact test is performed, it is possible to easily manufacture the wiring board 15 with an electronic element that is not peeled off and disconnected between the electronic element 14 and the wiring conductor 12.
[0041]
The protruding electrode 14a of the electronic element 14 is formed by repeatedly printing a conductive paste such as copper, silver, tungsten, or molybdenum on the surface of the electronic element 14 using a conventionally known screen printing method. . Furthermore, the protrusion shape of the electrode 14a of the electronic element 14 may be circular, elliptical, or polygonal in cross section in the direction parallel to the insulating layer 11a. From the viewpoint of relieving the stress at the connection portion, circular or elliptical. It is preferable that Further, the cross-sectional area of the electrode 14a in the direction parallel to the insulating layer 11a is larger than the connection with the electronic element 14 from the viewpoint of preventing air entrapment when the protruding electrode 14a is embedded in the through conductor 13b. Also, it is preferable that the tip portion is smaller. Further, the height T of the electrode 14a is preferably in the range of 0.1t to 0.5t, where t is the thickness of the insulating layer 11a. If the height T of the electrode 14a is less than 0.1t, a sufficient anchor effect is obtained. As a result, there is a tendency that the connection part is disconnected in the thermal shock test, and when it exceeds 0.5 t, the conductive paste is used when the wiring board 15 with electronic elements is finally pressed and heated to form a multilayer. However, there is a risk that it will protrude greatly from the through-hole 13a and cause poor adhesion between the insulating layers 11a. Therefore, the height T of the electrode 14a is preferably 0.1 t to 0.5 t with respect to the thickness t of the insulating layer 11a. Further, the diameter of the cross section of the projecting electrode 14a in the direction parallel to the insulating layer 11a is slightly smaller than the diameter of the through hole 16, and may be determined according to the required position accuracy.
[0042]
Thus, according to the method for manufacturing a wiring board with an electronic element of the present invention, it is possible to provide a wiring board with an electronic element having excellent connection reliability in which the electrodes of the electronic element and the wiring conductor are well connected.
[0043]
In the above-described example, an example in which the number of electronic elements mounted on the wiring board with electronic elements is one is shown. However, there is no problem in forming a plurality of electronic elements on the surface or inside of the wiring board.
[0046]
【Effect of the invention】
According to the present invention, there is provided a method of manufacturing a wiring board with an electronic element incorporating an electronic element, the steps of preparing first, second and third insulating layers, and forming a through hole in the second insulating layer, after filling the conductive paste, the exposed portion of the conductive paste positioned on one principal surface of the second insulating layer, wherein the wiring conductor to be connected to the exposed portion of the conductive paste second A step of transferring to one main surface of the insulating layer, a step of forming a through hole in the third insulating layer, the one main surface of the second insulating layer being formed on the first insulating layer, and a step of forming the second insulating layer on the second insulating layer. The first to third insulating layers are sequentially stacked so that the other main surface is in contact with the third insulating layer, and an electronic element having a protruding electrode is accommodated in the through hole of the third insulating layer. and while mounted on the other main surface of the second insulating layer, the insulating layer distal end portion of the electrode Burying from the other main surface to the conductive paste, since it comprises a step of curing the conductive paste, when embedding the protruding electrodes of the electronic element to the through conductors, to form the through conductors Since the conductive paste is in an uncured state, it can be embedded easily and by hardening the conductive paste, the electrodes of the electronic device can be firmly fixed to the through conductor, and as a result, a thermal shock test is performed. Even in this case, it is possible to easily manufacture a wiring board with an electronic element that does not peel off and break between the electronic element and the wiring conductor.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view showing a reference example of a wiring board with an electronic device of the present invention.
FIG. 2 is a cross-sectional view showing a reference example of a wiring board with electronic elements of the present invention.
FIGS. 3A to 3G are cross-sectional views for each process for explaining a method for manufacturing a wiring board with an electronic device according to the present invention. FIGS.
[Explanation of symbols]
1a ··············· Insulating layer 1, 11a ··········· Insulated substrate 2, 12 ······ Wiring conductors 3a, 13a .... Through-holes 3b, 13b ..... Penetration conductors 4,14 ..... Electronic elements 4a, 14a ..... Projection-like electrode 5. , 15 ... Wiring board with electronic elements

Claims (1)

Preparing first, second and third insulating layers;
After forming a through hole in the second insulating layer and filling the through hole with a conductive paste, the conductive paste is formed on an exposed portion of the conductive paste located on one main surface side of the second insulating layer. Transferring a wiring conductor to one main surface of the second insulating layer so as to be connected to the exposed portion of
Forming a through hole in the third insulating layer;
The first to third insulating layers are sequentially arranged so that the one main surface of the second insulating layer is in contact with the first insulating layer and the other main surface of the second insulating layer is in contact with the third insulating layer. as well as laminated, while accommodating the electronic device having a protruding electrode in the through hole of the third insulating layer mounted on the other main surface of the second insulating layer, the second insulating the tip of the electrode Embedding in the conductive paste from the other principal surface side of the layer;
And a step of curing the conductive paste. A method of manufacturing a wiring board with an electronic element incorporating the electronic element.

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