JP4671511B2 - Wiring board manufacturing method - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention provides a semiconductor element is mounted, a method for manufacturing a wiring board to be incorporated in various electronic apparatuses.
[0002]
[Prior art]
As a conventional wiring substrate, for example, as shown in FIG. 3, a plurality of conductor layers 12 are deposited in a predetermined pattern on the upper surface of a substrate 11 made of glass or ceramic, and a semiconductor element or the like is formed on the upper surface of the conductor layer 12. It is made of a metal with excellent corrosion resistance such as chromium, nickel, gold, etc. for the purpose of improving the bonding property when bonding an external electric circuit such as a flexible wiring board or preventing the conductor layer 12 from being corroded. A structure having a plating layer 13 is known.
[0003]
The plating layer 13 is generally formed by a conventionally known electroplating method. When the plating layer 13 is formed by such a method, the conductor layer 12 is formed on the upper surface of the substrate 11 in the electroplating process. A part of the plating lead layer 12a for connecting the power supply terminal to the left portion remains.
[0004]
In manufacturing such a wiring board, a substrate body that is slightly larger than the substrate 11 is used. After the plating layer 13 is formed on the surfaces of the conductor layer 12 and the plating lead layer 12a by the above-described electroplating method, the plating lead is formed. A predetermined wiring board is formed by externally processing an outer peripheral portion of a substrate body provided with a connection portion between the layer 12a and a power supply terminal by using a sharp cutter such as a dicing wheel, and cutting an unnecessary portion of the outer peripheral portion of the substrate body. Is obtained.
[0005]
[Problems to be solved by the invention]
By the way, when a wiring board is manufactured through the processes as described above, the end portion of the plating lead layer 12a is exposed when the substrate body is cut and the outer shape is processed.
[0006]
When such a plating lead layer 12a is formed of a conductive material containing silver (Ag), the silver contained in the plating lead layer 12a comes into contact with moisture in the atmosphere on the exposed surface, Oxidized and corroded. When such corrosion progresses over time, the silver corrosion reaches the conductor layer 12 formed continuously with the plating lead layer 12a, and as a result, it cannot function as a wiring board. Had drawbacks.
[0007]
Further, when such a conventional wiring board is used, if a potential difference occurs between adjacent conductor layers, migration may occur between adjacent plating lead layers on the end face of the substrate 11, and in this case, adjacent conductor layers may be Also had the disadvantage of being electrically shorted.
[0008]
The present invention has been made in view of the above drawbacks, and its object is provide a method of manufacturing a highly reliable wiring board capable of effectively preventing the corrosion of adjacent conductors interlayer short of the conductor layer There is to do.
[0010]
[Means for Solving the Problems]
In the method for manufacturing a wiring board according to the present invention, a conductor layer made of a conductive material is applied to the pattern forming region of the upper surface of the substrate body having the pattern forming region, and the conductor is applied from the pattern forming region to an area outside the region. A step of depositing a plating lead layer extending from the layer, a step of depositing a plating layer on the surfaces of the conductor layer and the plating lead layer, and an outer periphery of the pattern formation region with respect to the substrate body In addition to pressing from above, the substrate body, the plating lead layer, and the plating layer were cut at the outer periphery of the pattern formation region, so that the plating layer was rolled and covered so as to cover the end surface of the plating lead layer. And attaching to the end face of the substrate body.
In the method for manufacturing a wiring board according to the present invention, a plurality of conductor layers made of a conductive material containing silver in the pattern formation region of the upper surface of the substrate body having the pattern formation region may be disposed from the pattern formation region to the region. A step of depositing a plating lead layer extending from the conductor layer over a region outside the substrate, and connecting a power supply terminal for electroplating to the plating lead layer extending outside the pattern formation region and the substrate A step of depositing a plating layer made of at least one of nickel and gold on the surface of the conductor layer and the plating lead layer by immersing the element body in a plating solution; and a pattern forming region for the substrate element body The scribe wheel is pressed from above along the outer periphery of the substrate to cut the substrate body, the plating lead layer and the plating layer at the outer periphery of the pattern formation region, The end surface of the plating lead layer facing the cross, is characterized in that comprises a step of coating at the edge of the plating layer was allowed rolled by the pressing force of the scribing wheel, the.
[0011]
According to the present invention, since the end surface of the plating lead layer extending to the outer peripheral portion of the substrate is covered with the end portion of the plating layer deposited thereon, the conductive material containing silver is provided. The plating lead layer made of material is hardly corroded by contact with the atmosphere. Therefore, corrosion of the conductor layer etc. continuously formed with the plating lead layer is effectively prevented, and the wiring board is kept for a long time. It can function well.
[0012]
In this case, even if a potential difference occurs between adjacent conductor layers when the wiring board is used, the end surface of the plating lead layer is well covered with the plating layer, so that migration between adjacent plating lead layers on the end surface of the board is possible. Does not occur, and an electrical short circuit between adjacent conductor layers can be effectively prevented.
[0013]
In addition, according to the present invention, the above-described covering structure by the plating layer can be applied to the pattern forming region of the conductor layer with respect to the substrate body on which the conductor layer and the plating lead layer are adhered in a predetermined pattern in the external processing of the wiring board. When the substrate body, plating lead layer and plating layer are cut at the outer periphery of the pattern forming area by pressing the scribe wheel from above at the outer periphery of the substrate, it is made of nickel or gold having excellent malleability and corrosion resistance. Since the plating layer is simultaneously realized by rolling with the pressing force of the scribe wheel, such a coating structure can be obtained relatively easily without separately attaching the coating layer, and the productivity of the wiring board can be increased. There is also an advantage that it can be kept high.
[0014]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.
FIG. 1 is a cross-sectional view of a wiring board according to an embodiment of the present invention, wherein 1 is a substrate, 2 is a base layer, 3 is a conductor layer, 3a is a plating lead layer, and 4 is a plating layer.
[0015]
The substrate 1 is made of a glass material having a high softening point such as alumina ceramics, mullite, aluminum nitride, glass ceramics, quartz ceramic material, soda lime glass, alkali-free glass, and the like. A number of conductor layers 3 are deposited and function as a support base material that supports them.
[0016]
The underlayer 2 applied to the upper surface of the substrate 1 functions as an adhesion layer for firmly attaching a conductor layer 3 and a plating lead layer 3a, which will be described later, onto the substrate 1. For example, a low softening point glass material such as lead glass or bismuth glass, or a low softening point resin material such as polyimide resin or fluorine resin, and a plurality of conductor layers 3 have a predetermined pattern on the upper surface thereof. It is deposited and formed as it is.
[0017]
The conductor layer 3 is made of a conductive material containing, for example, 85 wt% or more of silver (Ag), and an adjacent conductor layer 3-3 is provided with an interval of, for example, 10 μm to 100 μm. For example, power of 5 mW to 15 mW is selectively applied individually.
[0018]
Further, a plating lead layer 3a is deposited and formed on the base layer 2 so as to extend from each conductor layer 3 to the outer periphery of the substrate.
[0019]
The plating lead layer 3a is for applying electric power to the conductor layer 3 when the plating layer 4 is formed on the surface of the conductor layer 3 by a conventionally known electroplating method. The conductive layer 3 is made of the same material as the layer 3 and contains silver, and is formed continuously with the conductive layer 3 with a substantially equal film thickness.
[0020]
A plating layer 4 made of nickel or gold is deposited on the surfaces of the conductor layer 3 and the plating lead layer 3a.
[0021]
The plated layer 4 is used to improve the bonding property when an external electric circuit such as a semiconductor element or a flexible wiring board is bonded to the conductor layer 3, or to prevent the conductor layer 3 from being corroded. And the thickness is set to 10% or more of the thickness of the conductor layer 3 or the plating lead layer 3a, and the end portions of the plating lead layers 3a located on the outer periphery of the substrate are covered with the end portions. It extends to the end surface.
[0022]
Since the end surface of the plating lead layer 3a extending to the outer peripheral portion of the substrate 1 is thus covered with the end portion of the plating layer 4, the silver contained in the conductor material forming the plating lead layer 3a. Is hardly corroded by contact with the atmosphere, and therefore corrosion of the plated lead layer 3a and the conductor layer 3 formed continuously can be effectively prevented, and the wiring board can function well over a long period of time. it can.
[0023]
In this case, even if a potential difference is generated between the adjacent conductor layers 3-3 when the wiring board is used, the end surface of the plating lead layer 3a is satisfactorily covered with the plating layer 4, so that the substrate 1 and the underlayer Migration does not occur between the adjacent plating lead layers 3a-3a at the end faces of the same, and electrical shorts between adjacent conductor layers can be effectively prevented.
[0024]
In order to achieve the above-described effect more reliably, it is preferable to extend the end of the plating layer 4 further downward to reach the end surface of the base layer 2 or the end surface of the substrate 1.
[0025]
Next, the manufacturing method of the wiring board described above will be described with reference to FIG.
(1) First, a substrate body 1 ′ that is slightly larger than the substrate 1 described above is prepared, and a base layer 2 is deposited on the upper surface thereof as shown in FIG.
[0026]
The substrate body 1 ′ has a pattern forming region corresponding to the substrate 1, and when the substrate body 1 ′ is made of alumina ceramics, an organic solvent suitable for ceramic raw material powders such as alumina, silica, and magnesia. Etc. are added and mixed to make a mud, and this is processed into a ceramic green sheet (ceramic green sheet) by a conventionally known doctor blade method or the like, and the green sheet is punched into a predetermined shape to obtain a high temperature (about 1600 ° C.) It is manufactured by baking.
[0027]
When the underlayer 2 is made of glass, for example, a predetermined glass paste obtained by adding and mixing a suitable organic solvent or the like to the powder of bismuth-based glass, for example, is formed on the upper surface of the substrate body 1 ′ by conventional well-known screen printing. The whole is printed and applied, and this is baked at a high temperature (for example, 500 ° C. to 580 ° C.) to be deposited and formed on the upper surface of the substrate body 1 ′ to have a thickness of, for example, 1 μm to 100 μm.
[0028]
(2) Next, as shown in FIG. 2 (b), a plurality of conductor layers 3 made of a conductor material containing silver in the pattern formation region in the upper surface of the substrate body 1 'to which the base layer 2 is applied. The plating lead layer 3a extending from the conductor layer 3 is deposited from the pattern formation region to the region outside the region.
[0029]
The conductor layer 3 and the plating lead layer 3a are formed on the upper surface of the underlayer 2 with a predetermined conductive paste 3 'obtained by adding and mixing an appropriate organic solvent, resin binder, glass frit, etc. to silver powder. A predetermined pattern is printed and applied by a printing method or the like, and this is baked at a high temperature (for example, 500 ° C. to 580 ° C.) to be simultaneously deposited and formed on the substrate body 1 ′. At this time, the plating lead layer 3 a is a pattern The shape extends across the outer periphery of the formation region to the outer region.
[0030]
(3) Next, as shown in FIG. 2 (c), a plated layer made of nickel or gold having excellent malleability and corrosion resistance on the surface of the conductor layer 3 and the plating lead layer 3a by a conventionally known electroplating method. 4 is formed.
[0031]
The plating layer 4 is connected to a plating lead layer 3a extending outside the pattern formation region with a power supply terminal for electric field plating, and in this state, the substrate body 1 'is placed in a plating solution for nickel plating or gold plating. By immersing and continuing to apply power to the conductor layer 3 and the plating lead layer 3a, the conductor layer 3 and the plating lead layer 3a are formed to have a thickness of, for example, 1 μm to 10 μm.
[0032]
At this time, it is important that the thickness of the plating layer 4 is set to 10% or more of the thickness of the conductor layer 3 or the plating lead layer 3a.
[0033]
(4) Finally, as shown in FIG. 2D, the substrate body 1 ′ is cut along the outer periphery of the pattern formation region, and an unnecessary portion of the outer periphery of the substrate body is cut off to obtain a wiring board. .
[0034]
The substrate body 1 ′ is cut by pressing the scribe wheel A from above along the outer periphery of the pattern formation region against the substrate body 1 ′, so that the substrate body 1 ′, the plating lead layer 3a, and the plating layer 4 are pressed. Is cut at the outer periphery of the pattern forming region. At this time, the plating layer 4 in the vicinity of the cut surface is rolled and thinly stretched by the pressing force of the scribe wheel A, and simultaneously faces the cut surface of the wiring board. Since the end portion of the plating lead layer 3a is pressure-bonded to the end surface of the plating lead layer 3a, the end portion of the plating lead layer 3a is satisfactorily covered with the end portion of the plating layer 4 and is not exposed to the outside.
[0035]
Therefore, as described above, corrosion of the plating lead layer 3a and the conductor layer 3 formed continuously with the plating lead layer 3a can be effectively prevented, and a potential difference is generated between the adjacent conductor layers 3-3 when the wiring board is used. Even if it occurs, migration of the plating lead layers 3a-3a on the end face of the substrate 1 can be effectively prevented, and the wiring substrate can be made to function well for a long time.
[0036]
Further, such a coating structure of the plating lead layer end portion by the plating layer 4 is a scribe wheel at the outer peripheral portion of the pattern forming region with respect to the substrate body 1 ′ to which the conductor layer 3 and the plating lead layer 3a are attached. Is pressed at the same time to cut the substrate body 1 ′, the plating lead layer 3a and the plating layer 4 at the same time, so that it can be obtained relatively easily without attaching a separate coating layer. High productivity of the wiring board can be maintained.
[0037]
In addition, this invention is not limited to the above-mentioned form, A various change, improvement, etc. are possible in the range which does not deviate from the summary of this invention.
[0038]
For example, in the above-described embodiment, gold plating or nickel plating is used as the plating layer 4. However, instead of this, nickel plating and gold plating may be laminated to form the plating layer 4.
[0039]
In the above-described embodiment, the conductor layer 3 and the plating lead layer 3a are formed on the substrate 1 via the base layer 2. However, the conductor layer 3 and the plating lead layer 3a are formed on the substrate without providing the base layer 2. It may be made to deposit and form directly on the upper surface of 1.
[0040]
Further, in the above-described embodiment, it is a matter of course that a part of the conductor layer 3 may be covered with a protective film made of epoxy resin or the like. In that case, the plating layer 4 is deposited on the entire surface of the conductor layer 3. Instead, it is deposited at least on the portion where the protective film is not present.
[0041]
【The invention's effect】
According to the present invention, since the end surface of the plating lead layer extending to the outer peripheral portion of the substrate is covered with the end portion of the plating layer deposited thereon, the conductive material containing silver is provided. The plating lead layer made of material is hardly corroded by contact with the atmosphere. Therefore, the corrosion of the conductor layer continuously formed with the plating lead layer is effectively prevented, and the wiring board is kept for a long time. It can function well.
[0042]
In this case, even if a potential difference occurs between adjacent conductor layers when the wiring board is used, the end surface of the plating lead layer is well covered with the plating layer, so that migration between adjacent plating lead layers on the end surface of the board is possible. Does not occur, and an electrical short circuit between adjacent conductor layers can be effectively prevented.
[0043]
In addition, according to the present invention, the above-described covering structure by the plating layer can be applied to the pattern forming region of the conductor layer with respect to the substrate body on which the conductor layer and the plating lead layer are adhered in a predetermined pattern in the external processing of the wiring board. When the substrate body, plating lead layer and plating layer are cut at the outer periphery of the pattern forming area by pressing the scribe wheel from above at the outer periphery of the substrate, it is made of nickel or gold having excellent malleability and corrosion resistance. Since the plating layer is simultaneously realized by rolling with the pressing force of the scribe wheel, such a coating structure can be obtained relatively easily without separately attaching the coating layer, and the productivity of the wiring board can be increased. There is also an advantage that it can be kept high.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view of a wiring board manufactured by a manufacturing method of the present invention.
FIGS. 2A to 2D are cross-sectional views for each step for explaining the manufacturing method of the present invention.
FIG. 3 is a cross-sectional view of a conventional wiring board.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Board | substrate, 3 ... Conductor layer, 3a ... Plating lead layer, 4 ... Plating layer

Claims (2)

Of the upper surface of the substrate body having a pattern formation region, a conductor layer made of a conductive material is provided in the pattern formation region, and a plating lead layer extending from the conductor layer from the pattern formation region to a region outside the region. A process of depositing;
Applying a plating layer to the surfaces of the conductor layer and the plating lead layer;
The substrate body is pressed from above along the outer periphery of the pattern formation region, and the substrate layer, the plating lead layer, and the plating layer are cut at the outer periphery of the pattern formation region, whereby the plating layer is A method of manufacturing a wiring board, comprising: attaching to the end face of the substrate body that is cut by rolling so as to cover the end face of the plating lead layer. A plurality of conductor layers made of a conductive material containing silver in the pattern formation region of the upper surface of the substrate body having the pattern formation region extend from the conductor layer from the pattern formation region to a region outside the region. Depositing the plated lead layer,
By connecting a power supply terminal for electroplating to a plating lead layer extending outside the pattern formation region and immersing the substrate body in a plating solution, nickel is formed on the surfaces of the conductor layer and the plating lead layer. Applying a plating layer made of at least one kind of gold;
A scribe wheel is pressed from above along the outer periphery of the pattern formation region against the substrate element body to cut the substrate element body, the plating lead layer and the plating layer at the outer periphery of the pattern formation region, and to the cut surface. Covering the end surface of the plating lead layer facing the substrate with the end portion of the plating layer rolled by the pressing force of the scribe wheel.

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