JP2003179176A - Wiring board - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve a problem that a wiring board cannot be bonded rigidly to an external electric circuit board due to the solder creeping up. <P>SOLUTION: The wiring board 7 comprises an insulating substrate 1 having an electronic component mounting part and a frame-like metal layer 3 surrounding the mounting part on the upper surface and a connection pad 4 at the outer circumferential part of the lower surface, and a castellation conductor 5 formed on the side face of the insulating substrate 1 and connecting the connection pad 4 with the frame-like metal layer 3. The castellation conductor 5 has a first region 5b being led out from the connection pad 4, and a second region 5c being led out from the frame-like metal layer 3 wherein the first region 5b and the second region 5c are shifted in the widthwise direction on the side face of the insulating substrate 1 and connected through a wiring layer 10 formed in the insulating substrate 1. Furthermore, a nickel layer 11 having mean crystal particle diameter of 100 nm or above is applied to the surface of the connection pad 4 and the first region 5b. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wiring board for mounting electronic components such as semiconductor elements and piezoelectric vibrators.

[0002]

2. Description of the Related Art Conventionally, a wiring board for mounting electronic components such as semiconductor elements and piezoelectric vibrators is generally made of a substantially rectangular plate-shaped ceramic material, and an insulating substrate having an electronic component mounting portion on its upper surface. A plurality of wiring layers led out from the electronic component mounting portion of the insulating substrate to the side surface through the inside of the insulating substrate, and a frame shape formed so as to surround the electronic component mounting portion on the upper surface of the insulating substrate. A metal layer, a plurality of connection pads formed on the outer peripheral surface of the lower surface of the insulating base, and a plurality of connection pads formed on the side surface of the insulating base for electrically connecting each wiring layer and each connection pad. An electronic component is mounted on the electronic component mounting portion of the insulating base, and each electrode for signal and ground of the electronic component is connected to each wiring layer by a conductive connecting member such as a bonding wire. After that, the metal lid made of iron-nickel-cobalt alloy or iron-nickel alloy is brazed to the frame-shaped metal layer on the upper surface of the insulating substrate so as to cover the electronic parts. An electronic device is obtained by joining the components through the above and sealing the electronic component.

In such an electronic device, a connection pad formed on the outer peripheral portion of the lower surface of the insulating substrate and a part of the castellation conductor are connected to a wiring conductor of an external electric circuit board through solder such as tin-lead solder or the like. The electrodes of the electronic component are mounted on the circuit board, and at the same time, the electrodes of the electronic component are electrically connected to the external electric circuit via the wiring layer, the castellation conductor, and the connection pads.

Of the castellation conductors, at least the electrode for grounding the electronic component is connected (usually about 20 to 50% of all the connection pads), a part of which is formed on the upper surface of the insulating substrate. The frame-shaped metal layer is also led out so that the frame-shaped metal layer can be grounded.

The castellation conductors are formed vertically on the side surfaces of the insulating base, and the castellation conductors connected to the frame-shaped metal layer are formed on the side surfaces of the insulating base from the lower surface to the upper surface. .

Further, a nickel layer is usually deposited and formed on the surface of each of the connection pads and the castellation conductor by an electroless method that does not require supply of plating power in order to increase the connection strength with solder. The nickel layer has a small average grain size of less than 20 nm because the nickel crystal growth is hindered by the co-deposition of the boron component and the phosphorus component which are decomposition products of the reducing agent in the electroless plating solution. Has become.

[0007]

However, in recent years,
Various electronic devices do not contain lead, such as tin-silver-bismuth type and tin-silver-copper-bismuth type, so-called lead-free, instead of tin-lead solder that is conventionally used to prevent adverse effects on the environment and human body. It is becoming more common to use solder to connect to an external electric circuit board, and lead-free solder is more likely to flow when melted than conventional tin-lead solder, so when mounting electronic devices on an external electric circuit board. , The solder propagates along the castellation conductor and crawls up to the frame-shaped metal layer on the upper surface of the insulating substrate or the metal lid attached to the frame-shaped metal layer, and as a result, the connection pad of the insulating substrate and the external electric circuit. However, the amount of solder intervening between the wiring conductor and the wiring conductor is extremely small, so that the electronic device cannot be firmly mounted on the external circuit board.

In addition, lead-free solder such as tin-silver-bismuth-based solder tends to segregate components such as bismuth as compared with conventional tin-lead solder, and is formed on the surface of the connection pad or castellation conductor. The average grain size of the crystals of the nickel layer is as small as less than 20 nm and the reactivity with bismuth is low,
The size of the wiring board has reduced the size of the connection pads and castellation conductors, and the area of solder joints has become smaller. When lead-free solder such as tin-silver-bismuth-based solder is connected, the components such as bismuth of the lead-free solder segregate and the connection becomes weak.As a result, heat is generated between the electronic device and the external electric circuit board. When a thermal stress occurs due to the difference in thermal expansion coefficient between the insulating base of the electronic device and the external electric circuit board, the thermal stress causes lead-free solder to move from the connection pad or castellation conductor. There is also a disadvantage that the reliability of the connection of the electronic device to the external circuit board is low due to peeling.

The present invention has been devised in view of the above-mentioned drawbacks, and an object thereof is to firmly bond a connection pad to a wiring conductor of an external electric circuit board via lead-free solder, whereby an external electric circuit is formed. An object of the present invention is to provide a wiring board that can be mounted on the board firmly and with high reliability.

[0010]

According to the present invention, there is provided an insulating base having an electronic component mounting portion and a frame-shaped metal layer surrounding the mounting portion on an upper surface and a connection pad on an outer peripheral portion of a lower surface, and the insulating base. And a castellation conductor formed on the side surface of the connection pad for connecting the connection pad and the frame-shaped metal layer, wherein the castellation conductor has a first region extending from the connection pad and a frame-shaped A second region extending from the metal layer, wherein the first region and the second region are misaligned in the width direction of the side surface of the insulating base and are connected via an internal wiring layer formed inside the insulating base. And a nickel layer having an average crystal grain size of 100 nm or more is deposited on the surface of the connection pad and / or the first region.

Further, the wiring board of the present invention is characterized in that the thickness of the nickel layer deposited on the surface of the connection pad and / or the first region is 2 μm or more.

According to the wiring board of the present invention, the castellation conductor for electrically connecting the frame-shaped metal layer formed on the upper surface of the insulating base and the connection pad formed on the lower surface of the insulating base is provided from the connection pad. The connecting pad and the external electric circuit are composed of the first region to be led out and the second region to be led out from the metal layer, and the first region and the second region are displaced in the width direction of the side surface of the insulating substrate. Even if the lead conductor is connected to the wiring conductor using lead-free solder, the lead-free solder does not crawl up through the castellation conductor to the frame-shaped metal layer or metal lid, and as a result, the connection pad and external electrical A sufficient amount of solder can be interposed between the wiring conductor of the circuit board and the wiring board (electronic device).
Can be connected extremely firmly to the external electric circuit board.

Further, according to the wiring board of the present invention, on the surface of the first region of the connection pad and / or the castellation conductor, the average grain size of the crystal is 100 nm or more and the reactivity with the bismuth component in the lead-free solder is provided. The nickel layer having improved heat resistance is deposited to a thickness of, for example, 2 μm or more, so that the connection pad and the surface of the first region of the castellation conductor derived from the connection pad are lead-free soldered to the wiring conductor of the external electric circuit. When connected using, even if the bismuth component in the lead-free solder tries to segregate, this bismuth component forms an intermetallic compound with nickel and the bismuth component is effectively absorbed and segregation is effectively prevented, As a result, the connection pads of the wiring board and the first of the castellation conductors are
The area and the wiring conductor of the external electric circuit board are firmly connected via lead-free solder such as tin-silver-bismuth system, heat is applied to the wiring board and the external electric circuit board, and thermal expansion of both occurs. Even if thermal stress is generated due to the difference in the coefficient, the lead-free solder is not separated from the connection pad or the castellation conductor by the thermal stress, and the connection pad is firmly and highly connected to the wiring conductor of the external electric circuit board. It is possible to connect with reliability.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, the present invention will be described in detail with reference to the accompanying drawings. 1 (a) to 1 (c) show an embodiment in which the wiring board of the present invention is applied to a semiconductor element housing package for housing a semiconductor element, 1 is an insulating base,
Reference numeral 2 is a wiring layer, 3 is a frame-shaped metal layer, 4 is a connection pad, and 5 is a castellation conductor. The insulating substrate 1, the wiring layer 2, the frame-shaped metal layer 3, the connection pads 4, and the castellation conductors 5 form a wiring board 7 for mounting the semiconductor element 6.

The insulating substrate 1 is made of an aluminum oxide sintered body, an aluminum nitride sintered body, a mullite sintered body,
It is made of an electrically insulating material such as a glass ceramic sintered body, and has a mounting portion on which the semiconductor element 6 is mounted, and the semiconductor element 6 is bonded to the mounting portion via an adhesive material such as glass, resin, or brazing material. Fixed.

When the insulating substrate 1 is made of, for example, an aluminum oxide sintered body, an appropriate organic binder and solvent are added to and mixed with raw material powders of aluminum oxide, silicon oxide, calcium oxide, magnesium oxide and the like. A ceramic green sheet (ceramic green sheet) which is not formed into a slurry-like ceramic slurry, and is then formed into a sheet shape by a conventionally known sheet forming technique such as a doctor blade method or a calendar roll method.
Finally, a plurality of the ceramic green sheets are laminated and fired at a temperature of about 1600 ° C. in a reducing atmosphere.

A plurality of wiring layers 2 are formed on the upper surface of the insulating substrate 1 from around the mounting portion on which the semiconductor element 6 is mounted to the side surface through the inside of the insulating substrate 1 and the wiring layer 2 is a semiconductor. The signal and ground electrodes of the element 6 act as conductive paths for connecting to the connection pads 4, and the signal and ground electrodes of the semiconductor element 6 have bonding wires 8 at one end on the mounting portion side. Electrically connected via.

The wiring layer 2 is made of metal powder such as tungsten, molybdenum, manganese, copper, silver, gold and palladium. A metal paste obtained by adding and mixing a suitable organic binder or solvent to the metal powder such as tungsten. The ceramic green sheet to be the insulating substrate 1 is printed and applied in advance in a predetermined pattern by a conventionally known screen printing method, so that the ceramic green sheet is adhered and formed from the upper surface of the insulating substrate 1 to the side surface through the inside of the insulating substrate 1.

A frame-shaped metal layer 3 is deposited on the upper surface of the insulating substrate 1 so as to surround a mounting portion on which the semiconductor element 6 is mounted. The frame-shaped metal layer 3 will be described later. It acts as a base metal layer when attaching the metallic lid 9 to the insulating substrate 1, and is formed of a metal powder such as tungsten, molybdenum, manganese, copper, silver, gold, or palladium.

The frame-shaped metal layer 3 has a metal lid 9 made of gold.
The semiconductor element 6 mounted on the semiconductor element mounting portion of the insulating substrate 1 is hermetically sealed from the atmosphere by being brazed and attached via a brazing material such as tin.

The frame-shaped metal layer 3 is the wiring layer 2 described above.
It is formed on the upper surface of the insulating base 1 so as to surround the semiconductor element mounting portion by a method similar to.

Further, a plurality of connecting pads 4 are formed on the outer peripheral portion of the lower surface of the insulating substrate 1, and the connecting pads 4 are connected to the wiring conductors of the external electric circuit board via lead-free solder, and the semiconductor element is formed. 6 serves to electrically connect the signal and ground electrodes 6 to an external electric circuit.

The connection pad 4 is made of metal powder such as tungsten, molybdenum, manganese, copper, silver, gold, palladium, etc. It is formed.

Further, a plurality of castellation conductors 5 (conductors formed in the recesses having a semicircular cross section on the side surfaces of the insulating base 1 and formed in the recesses) are attached to the side surface of the insulating base 1. The castellation conductor 5 serves to electrically connect the wiring layer 2 and the connection pad 4.

The castellation conductor 5 is made of a metal powder such as tungsten, molybdenum, manganese, copper, silver, gold, palladium, etc., and a semicircular recess is formed on the side surface of the ceramic green sheet to be the insulating substrate 1 by a punching method. In addition, a metal paste obtained by adding and mixing a suitable organic binder or solvent to a metal powder such as tungsten is mixed and printed in a predetermined pattern by a conventionally known screen printing method in the concave portion of the insulating substrate 1. The side surface is formed in a predetermined shape.

The castellation conductor 5 is partially connected to the wiring layer 2 which is electrically connected to the ground electrode of the semiconductor element 6, and a part thereof is the frame-shaped metal layer 3 on the upper surface of the insulating substrate 1.
And the frame-shaped metal layer 3 is grounded.

The wiring layer 2 and the frame-shaped metal layer 3
The wiring layer 2 or the frame-like structure is formed by depositing a plating layer made of a metal having good corrosion resistance such as nickel or gold, bonding property of the bonding wire 8 and wettability of the brazing material on the exposed surface. It is possible to effectively prevent the oxidative corrosion of the metal layer 3 and the like, and securely and firmly attach the metal lid 9 to the frame-shaped metal layer 3. Therefore, the wiring layer 2 and the frame-shaped metal layer 3 have nickel, nickel,
It is preferable to deposit a metal having good corrosion resistance such as gold, bonding property, and wettability of a brazing material by a plating method. Particularly, for example, a nickel plating layer having a thickness of 1 to 10 μm, 0.05 to It is preferable to successively deposit a gold plating layer having a thickness of 3 μm.

In this case, the thickness of the gold plating layer may be different depending on the part to be deposited, the crystal orientation of the gold plating layer, etc. For example, the crystal orientation in the X-ray diffraction of the gold plating layer is (111) as much as possible. ) Make sure that it is aligned with the surface,
The entire area including the area to which the bonding wire 8 is connected may be set to about 0.3 to 1 μm, and only the brazing area should be thin, about 0.3 μm or less. It is also possible to suppress the formation of the compound and further improve the reliability of brazing.

Thus, according to the wiring board 7 of the present invention, the semiconductor element 6 is mounted on the mounting portion on the upper surface of the insulating substrate 1, and the signal and ground electrodes of the semiconductor element 6 are provided with the bonding wires 8 on the wiring layer 2. After that, a metal lid 9 made of an iron-nickel-cobalt alloy, an iron-nickel alloy or the like is joined to the frame-shaped metal layer 3 on the upper surface of the insulating substrate 1 via a brazing material, An electronic device (semiconductor device) as a product is completed by hermetically sealing the semiconductor element 6 with the lid 9.

The semiconductor device is mounted on the external electric circuit board by connecting the connection pads 4 on the outer peripheral surface of the lower surface of the insulating substrate 1 to the wiring conductors of the external electric circuit board via lead-free solder, and at the same time, the semiconductor element 6 is mounted. The signal and ground electrodes are electrically connected to the wiring conductors of the external electric circuit board.

In the wiring board 7 of the present invention, of the castellation conductors 5, the castellation conductors 5a connecting the frame-shaped metal layer 3 and the connection pads 4 are led out from the connection pads 4 as shown in FIG. The first region 5b is divided into the first region 5b and the second region 5c derived from the frame-shaped metal layer 3, and the first region 5b and the second region 5c are displaced in the width direction of the side surface of the insulating substrate 1 and the insulating substrate 1 is formed. It is important to be electrically connected internally via the internal wiring layer 10.

The castellation conductor 5a connecting the frame-shaped metal layer 3 and the connection pad 4 is divided into a first region 5b extending from the connection pad 4 and a second region 5c extending from the frame-shaped metal layer 3. Separately, if the respective positions are shifted in the width direction of the side surface of the insulating substrate 1, even if the connection pad 4 and the wiring conductor of the external electric circuit are connected by using lead-free solder,
The lead-free solder does not reach the frame-shaped metal layer 3 and the metal lid 9 along the castellation conductor, and as a result, a sufficient amount is provided between the connection pad 4 and the wiring conductor of the external electric circuit board. The solder can be interposed, and the wiring board (electronic device) can be connected extremely firmly to the external electric circuit board.

The division position between the first region 5b and the second region 5c of the castellation conductor 5a connecting the frame-shaped metal layer 3 and the connection pad 4 is determined by the type of solder used and the insulating substrate. The thickness of the wiring layer 2 and the design convenience of the wiring layer 2 may be appropriately determined. For example, the castellation conductor 5a has a semi-circular shape with a diameter of 0.3 mm to 0.7 mm, and tin is used as solder. If silver-bismuth solder is used, set the length of the first region 5b to 0.3 mm to 1 mm.
The range may be.

In the present invention, as shown in FIG.
Connection pad 4 and / or castellation conductor 5
Of the nickel layer 11 having an average crystal grain size of 100 nm or more on the surface of the first region 5b derived from the connection pad 4
It is important to keep it on.

Thus, the average grain size of the crystal is 1 on the surface of the connection pad 4 and the first region 5b of the castellation conductor 5.
When the nickel layer 11 having a large size of 00 nm or more is deposited, the nickel layer 11 having a large average grain size of the crystal is formed on the surface of the connection pad 4 and the surface of the first region 5b of the castellation conductor 5 derived from the connection pad 4. When the lead-free solder is connected to the wiring conductor of the external electric circuit using the bismuth component in the lead-free solder, the bismuth component forms an intermetallic compound with nickel and the bismuth component is effective. Are effectively absorbed and segregation is effectively prevented. As a result, the connection pad 4 of the wiring board 7 and the first region 5b of the castellation conductor 5 and the wiring conductor of the external electric circuit board are made of a tin-silver-bismuth system or the like. It is firmly connected via lead-free solder, heat acts on the wiring board 7 and the external electric circuit board, and thermal stress is generated between them due to the difference in thermal expansion coefficient between them. The first region 5b lead-free solder of the connection pads 4 and castellation conductor 5 by heat stress
The connection pad 4 can be firmly and highly reliably connected to the wiring conductor of the external electric circuit board without further peeling.

The nickel layer 11 having an average crystal grain size of 100 nm or more has a grain size of less than 100 nm (usually 2 nm by an electroless plating method using a boron-based reducing agent).
It can be formed by depositing a nickel layer (less than 0 nm) on the surfaces of the connection pad 4 and the castellation conductor 5 and then heat treating the nickel layer at about 800 ° C. to grow crystals.

If the average grain size of crystals of the nickel layer 11 is less than 100 nm, segregation of components such as bismuth in the lead-free solder cannot be effectively prevented, and the connection pad 4 of the external electric circuit board is prevented. It cannot be firmly and reliably connected to the wiring conductor. Therefore, the nickel layer 11 is specified to have an average crystal grain size of 100 nm or more. In particular, the average grain size of the crystals of the nickel layer 11 is set to 2
When it is set to be in the range of 00 to 4000 nm (0.2 μm to 4 μm), the crystal plane becomes larger and at the same time, grain boundaries are appropriately present, so that the bismuth component can be more surely absorbed and at the grain boundaries, nickel can be absorbed. The connection pad 4 and the castellation conductor 5 are relieved by relaxing the internal stress of the layer 11.
On the other hand, the nickel layer 11 can be applied more firmly. Therefore, the nickel layer 11 has an average crystal grain size of 200 nm to 4000 nm (0.2 μm to 4 μm).
The range of m) is preferable.

Further, the nickel layer 11 has a thickness of 2
If it is set to be not less than μm, the components such as bismuth in the lead-free solder and nickel in the nickel layer 11 satisfactorily generate intermetallic compounds, and the segregation of the components such as bismuth in the lead-free solder can be effectively prevented. Therefore, the connection pad 4 can be firmly and highly reliably connected to the wiring conductor of the external electric circuit board. Therefore, it is preferable that the nickel layer 11 has a thickness of 2 μm or more.

Furthermore, the nickel layer 11 has a gold layer (not shown) on its exposed surface, for example, 0.05 to 3 μm.
If it is adhered with a thickness of 1, the oxidation and corrosion can be effectively prevented, and the reliability of connection of lead-free solder or the like can be further improved. Therefore, the nickel layer 1
1 is a gold layer on its exposed surface, for example 0.05-3 μm
It is preferable to apply the same thickness.

Furthermore, as shown in FIG. 4, the first region 5b extending from the connection pad 4 of the castellation conductor 5 is formed with a protruding portion 12 protruding inward, so that the connection pad 4 is electrically connected to the outside. When the wiring conductors of the circuit board are joined via solder, the protrusions 12 are joined so as to dig into the solder, and the joining strength is further strengthened. Therefore, the first region 5b derived from the connection pad 4 of the castellation conductor 5 is, as shown in FIG.
It is preferable to form a protrusion 12 that protrudes inward.

The present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the gist of the present invention. For example, in the above-mentioned embodiments, the wiring of the present invention is used. Although the substrate is applied to the semiconductor element housing package that houses the semiconductor element, it may be applied to other applications such as a hybrid integrated circuit board.

[0042]

According to the wiring board of the present invention, the castellation conductor for electrically connecting the frame-shaped metal layer formed on the upper surface of the insulating base and the connection pad formed on the lower surface of the insulating base is connected. The first region is derived from the pad and the second region is derived from the metal layer, and
Since the first region and the second region are displaced in the width direction of the side surface of the insulating substrate, the lead-free solder is castellated even if the connection pad and the wiring conductor of the external electric circuit are connected by using the lead-free solder. It does not crawl along the conductor to the frame-shaped metal layer or metal lid, and as a result, a sufficient amount of solder can be interposed between the connection pad and the wiring conductor of the external electric circuit board, The wiring board (electronic device) can be connected extremely firmly to the external electric circuit board.

Further, according to the wiring board of the present invention, on the surface of the first region of the connection pad and / or the castellation conductor, the average grain size of the crystal is 100 nm or more, and the reactivity with the bismuth component in the lead-free solder is obtained. The nickel layer having improved heat resistance is deposited to a thickness of, for example, 2 μm or more, so that the connection pad and the surface of the first region of the castellation conductor derived from the connection pad are lead-free soldered to the wiring conductor of the external electric circuit. When connected using, even if the bismuth component in the lead-free solder tries to segregate, this bismuth component forms an intermetallic compound with nickel and the bismuth component is effectively absorbed and segregation is effectively prevented, As a result, the connection pads of the wiring board and the first of the castellation conductors are
The area and the wiring conductor of the external electric circuit board are firmly connected via lead-free solder such as tin-silver-bismuth system, heat is applied to the wiring board and the external electric circuit board, and thermal expansion of both occurs. Even if a thermal stress caused by the difference in the coefficient is generated, the lead-free solder is not separated from the connection pad or the castellation conductor by the thermal stress, the connection pad is firmly attached to the wiring conductor of the external electric circuit board, and It is possible to connect with high reliability.

[Brief description of drawings]

1A, 1B and 1C are a side view, a plan view and a bottom view showing an embodiment of a wiring board of the present invention.

FIG. 2 is an enlarged perspective view of a main part of the wiring board of the present invention.

FIG. 3 is an enlarged cross-sectional view of a main part of the wiring board of the present invention.

FIG. 4 is an enlarged view of a main part of another embodiment of the wiring board according to the present invention.

[Explanation of symbols]

1 ... Insulating substrate 2 ... Wiring layer 3 ... Frame-shaped metal layer 4 ... Connection pad 5 ... Castellation conductor 5a ... Castellation conductor 5b connecting the pad and the frame-shaped metal layer ... First region 5c ... Second region 6 ... Semiconductor element 7 ... Wiring substrate 8 ... ... Bonding wire 9 ... Lid 10 ... Internal wiring layer 11 ... Nickel layer 12 ... Projection

Front page continuation (51) Int.Cl. ⁷ Identification code FI theme code (reference) H05K 3/46 H01L 23/12 LF term (reference) 5E317 AA22 BB04 BB11 CC22 CC31 CC52 CD21 CD31 GG07 5E338 AA03 AA18 BB02 BB19 BB63 BB65 BB75 CC01 CC04 CC06 CD02 CD32 EE51 5E346 AA12 AA15 AA41 BB01 BB16 CC17 CC31 CC32 CC35 CC37 CC38 CC39 DD02 DD22 DD34 EE24 FF42 GG03 GG06 GG08 GG10 HH07

Claims (2)

[Claims] 1. An insulating base having an electronic component mounting portion on the upper surface and a frame-shaped metal layer surrounding the mounting portion, and a connection pad on the outer peripheral portion of the lower surface, and formed on a side surface of the insulating base.
A wiring board comprising a castellation conductor that connects the connection pad and a frame-shaped metal layer, wherein the castellation conductor is a first region derived from the connection pad and a first region derived from the frame-shaped metal layer. Two regions, the first region and the second region are displaced from each other in the width direction of the side surface of the insulating base, and are connected through an internal wiring layer formed inside the insulating base, and the connection is made. On the surface of the pad and / or the first region, the average crystal grain size is 10
A wiring board having a nickel layer of 0 nm or more deposited thereon. 2. The wiring board according to claim 1, wherein the thickness of the nickel layer deposited on the surface of the connection pad and / or the first region is 2 μm or more.