JP2003273611A - Wiring board - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a wiring board appropriate for packaging an electronic component to be operated at high speed by relaxing an inconsistency of characteristic impedance in the connection part of a connection pad to connect the high frequency signal electrode of the electronic component and a wiring conductor. <P>SOLUTION: In a wiring board 1, a connection pad 2 to connect the high frequency signal electrode of the electronic component, a wiring board 5 led out of the connection pad 2 for transmitting a high frequency signal and an insulation protecting layer 3 for covering the peripheral parts of the wiring conductor 5 and the connection pad 2 are formed on the surface of an insulated substrate 4, the insulation protecting layer 3 covers the wiring conductor 5 from an opening 8 on the connection pad 2 to the end of the length of (2n-1)/4 multiple ((n) is a natural number) of the wavelength of the high frequency signal and the wiring conductor 5 is exposed beyond the end of the length Inconsistency of characteristic impedance in the wiring conductor 5 caused by a nonuniformity in thickness of the insulation protecting layer 3 can be prevented, a transmission loss is reduced and signal delay does not occur, either. <P>COPYRIGHT: (C)2003,JPO

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention
Related to wiring boards on which conductive elements and electronic components are mounted
It is. [0002] Conventionally, microprocessors and ASICs
(Application Specific Integrated Circuit) etc.
Electronic components such as semiconductor elements
In multilayer wiring boards used for electronic circuit boards, etc.
When forming wiring conductors for internal wiring,
Insulation made of ceramics including ceramics
Layer and wiring conductor made of refractory metal such as tungsten (W)
The multilayer wiring board is formed by alternately stacking the body layers. However, in such a multilayer wiring board,
Is made of alumina ceramics whose insulating layer has a relative dielectric constant of about 10.
Because it is made of ceramics,
Crosstalk noise due to increased magnetic coupling
Increase the operating speed of semiconductor devices.
There was a problem that it could not be handled. Therefore, the insulating layer has a relative dielectric constant of about 10.
Instead of alumina ceramics, the relative dielectric constant is 3-5.
Polyimide or relatively small glass epoxy resin substrate
So-called formed using organic materials such as epoxy resin
Build-up multilayer wiring boards are being used
Was. [0005] Such a build-up multilayer wiring board has
Manufactured by the semi-additive method, etc.
Reinforced with about 0.6-1.6mm glass cloth
On a resin substrate, a wiring conductor made of copper etc. and an interlayer resin insulation layer
Are alternately laminated. This multilayer arrangement
The connection between the wiring conductors via the interlayer resin insulation layer of the wiring board
It is performed by a via hole. [0006] Conventionally, build-up multilayer wiring boards, for example,
For example, it is manufactured by a method disclosed in JP-A-9-130050.
It is built. That is, first, the copper foil was stuck
Forming through-holes in the copper-clad laminate, followed by electroless plating
To form a through hole. Then,
Distribute by etching the surface copper foil of the board into a wiring pattern
A wire conductor is formed, and an interlayer resin insulation layer is formed on the surface of the wire conductor.
After forming the coating, the via hole is formed by drilling such as laser processing.
Layer, followed by a hardening treatment
An interlayer insulating resin layer is formed. Further, a roughened surface forming process is performed on the interlayer insulating resin layer.
To form a thin electroless plating film on the roughened surface
And a plating resist is formed on the electroless plating film.
After plating, thicken the plating film by electrolytic plating.
After removing the resist, etching is performed, and the lower layer
Form a wiring conductor connected to the wire conductor by via holes
You. After repeating this, the wiring layer is formed as the outermost layer.
Insulation protection by covering the wiring conductor to protect the body
A layer is formed on the part of the wiring conductor that will become the connection pad.
An opening is formed in the insulating protective layer of
After applying the plating etc. to the wiring conductor for the minute to make the connection pad,
By forming solder bumps on these connection pads,
Manufacture a build-up multilayer wiring board. [0009] The conventional multilayer wiring board manufactured in this manner.
In the board, epoxy resin etc. is used for the insulation protection layer
However, epoxy resin has a relative dielectric constant of 3.0 in the GHz band.
LS using high frequency signals in the GHz band
When an I chip or the like is mounted, the insulating protective layer has a high dielectric constant
Signal delay and signal error
There was a problem that it would be. In order to solve such a problem,
As disclosed in, for example, JP 2001-94263 A
Using an insulating protective layer made of an insulating material with a low dielectric constant.
A multilayer wiring board has been proposed. In such a multilayer wiring board, the dielectric constant is 3.
The wiring conductor is formed under the insulating protective layer with a low dielectric constant of 0 or less.
Signal delay and signal error
Problem could be solved to some extent. [0012] However, in recent years, I
The distance between the electrode terminals of the IC chip due to the high integration of the C chip
Is becoming narrower, so the wiring width of the multilayer wiring board
It's getting thinner. Here, the wiring width and the thickness of the wiring conductor
The characteristic impedance due to the contrast is the wiring conductor and the
Between the power supply conductor layer and the ground conductor layer facing each other at a fixed distance
Matched by electromagnetic coupling. Therefore, the wiring width
As insulation becomes thinner, insulation between wiring conductors is ensured.
Edge resin layer and insulating protective layer are thinner and more stable
It was necessary to form with the thickness set. The function of the IC chip is as follows.
Circuits such as plexers and demultiplexers provide low-frequency signals.
Function to multiplex signals and output them as high-frequency signals.
Functions such as splitting a wave signal and outputting it as a low-frequency signal
Some are provided with. Such an IC chip is mounted
In multi-layer wiring boards, many low frequency signals and high frequency
There is a need to transmit a small number of waves together. So
In the case of, the wiring conductor that transmits the high-frequency signal is conductor resistance
Due to the need to reduce losses due to
Design with a wiring width wider than the wave signal wiring conductor
The need came out. However, organic resins such as epoxy resins
The thickness of the insulating protection layer formed of the material
Fill the dents affected by the unevenness of the formed wiring conductor
That the width of the wiring conductor is uneven
Therefore, it is difficult to uniformly form the thickness of the insulating protective layer.
There was a problem that. In addition, the characteristic impedance
Dance matching cannot be performed, and multiplexing is performed on the IC chip.
The transmission loss of high-frequency signals
There was a title. For example, a microprocessor is mounted.
In a multilayer wiring board, a clock signal that is a basic signal
Highest frequency signal, but transmission loss is large
Signal rise time is delayed
There is a problem that a malfunction of the device is easily caused. The present invention solves such problems of the prior art.
The purpose of this was Epoch.
Thickness of insulating protection layer formed of resin and other materials
Is affected by the unevenness of the wiring conductor formed on the underlayer.
Matching of characteristic impedance by uniform formation
Have variations that adversely affect
Eliminate the effects of geometric dimensional changes
Connects to the power supply conductor layer and the ground conductor layer around the insulation protection layer
By stabilizing the electromagnetic coupling,
When transmitting low-frequency signals and high-frequency signals in the band
Has an insulating protective film structure with low transmission loss
It is to provide a wiring board. According to the present invention, there is provided a wiring board comprising:
The electrodes for high-frequency signals of electronic components are connected to the surface of the edge substrate.
Connection pad and the height derived from this connection pad.
A wiring conductor for transmitting high-frequency signals,
An insulating protective layer covering the periphery of the connection pad is formed.
And the insulating protective layer is high from an opening on the connection pad.
(2n-1) / 4 times (n is a natural number) of the wavelength of the frequency signal
It covers the wiring conductor to the position of the length, from there
Characterized in that the wiring conductor is exposed.
It is. According to the wiring board of the present invention, the mounted
From the connection pad to which the high-frequency signal electrode of the
For derived wiring conductors that transmit high-frequency signals,
It is essential to cover this wiring conductor with the periphery of the connection pad.
The edge protection layer passes through the opening on the connection pad through (2)
(n-1) / 4 times (n is a natural number)
Not to expose the wiring conductor of the part from there.
Since the formation part is provided, the exposed part of the wiring conductor
The dielectric constant above is a small relative dielectric constant of 1 due to air.
And made of epoxy resin and other materials
The thickness of the insulating protective layer depends on the wiring conductor formed on the underlayer.
Is unevenly formed under the influence of uneven
Variation that adversely affects the impedance matching
The effect of geometric dimensional changes
Can be eliminated. As a result, insulation from the wiring conductor is maintained.
To the power supply conductor layer and the ground conductor layer
Because magnetic coupling can be stabilized,
Impedance does not change and high-frequency signals
Characteristic impedance mismatch in transmitting wiring conductors
Can be effectively prevented from occurring. Further, the insulating protective layer may be formed in an opening on the connection pad.
To (2n-1) / 4 times the length of the high-frequency signal
Not covered with an insulating protective layer
High frequency signal from the opening on the wiring conductor and connection pad of the part
To the position of (2n-1) / 4 times the wavelength of
The amount of high-frequency signal reflection at the connection point with the
(2n-) of the wavelength of the high-frequency signal from the opening on the connection pad.
1) Connect the part covered up to the position / 4 times the length
Equal to the amount of high-frequency signal reflection at the connection point
Become. As a result, it arises from characteristic impedance mismatch
Efficient suppression of high frequency signal reflection noise
can do. Also, electronic parts and the like are mounted on the connection pads.
When joining with solder, etc., keep the insulation on the connection pads.
(2n-1) / 4 of the wavelength of the high-frequency signal from the opening of the protective layer
Wiring conductors up to double the length are covered with an insulating protective layer.
Prevents the flow of solder or other liquid onto the wiring conductor.
It can be stopped, so that solder etc. flows into the wiring conductor
Resulting from the characteristic impedance mismatch
And efficiently suppress high frequency signal reflection noise
Can be. DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a wiring board of the present invention will be described.
This will be described in detail with reference to the accompanying drawings. FIG. 1 shows an embodiment of a wiring board according to the present invention.
It is a perspective view showing an example. In FIG. 1, 1 is a wiring board,
4 is an insulating resin layer as an insulating substrate, 2 is an insulating resin layer 4
The connection pads 5 formed on the surface are connected to the connection pads 2.
The output wiring conductor for transmitting the high-frequency signal and the wiring conductor 3
Insulation protection for covering the periphery of the body 5 and the connection pad 2
The layer 7 is formed on substantially the entire back surface of the insulating resin layer 4.
Ground conductor or power supply conductor that also serves as the ground. The peripheral portions of the wiring conductor 5 and the connection pad 2 are
The insulating protective layer 3 to be covered is protected from oxidation by air or the like.
For the wiring board 1 of the present invention.
Is transmitted from the opening 8 on the connection pad 2 by the wiring conductor 5.
The position of the length L of about 1/4 of the wavelength of the transmitted high frequency signal
A non-formed portion 6 is provided on the insulating protective layer 3 at the tip, and
The portion of the wiring conductor 5 is exposed. Here, the wiring conductor 5 is a ground conductor or
Due to the electromagnetic coupling with the power supply conductor 7, the exposed
Set the characteristic impedance of the part to be, for example, 50Ω.
It is desirable that it be measured. In particular,
Impedance is within 10% of 50Ω
Is desirable. For example, if the insulating resin layer 4
A resin with a relative dielectric constant of about 4 and a thickness of about 90 μm
In this case, the wiring conductor 5 has a wiring width of about 180 μm.
You. At this time, the thickness of the wiring conductor 5 is in the range of 1 to 50 μm.
It is possible to match the characteristic impedance
However, in order to reduce the resistance of the wiring conductor 5,
The thickness of the body 5 should be 5 μm or more and the resistance should be small.
Is preferred. The wiring conductor 5 has a high frequency signal.
In order to reduce the resistance to
It is more effective to apply it. The wiring conductor 5 includes electronic components (not shown).
) Is mounted and the connection to which the high-frequency signal electrode is connected
The connection pad 2 is connected, and the wiring conductor 5 is connected to this connection pad.
2 is derived. The shape of this connection pad 2
Means square, rectangle, in addition to the circle as shown
Shape, diamond shape, hexagonal shape or octagonal shape and other irregularities
The shape may be, but the viewpoint corresponding to the operation of the high-speed signal
From a circular shape to reduce excess stray capacitance.
It is desirable to keep. The connection pad 2 has an electronic part.
For connecting the high-frequency signal electrode
Fields, etc., are joined to each other.
Plating, gold plating, etc. are preferred
No. Further, the connection pad 2 and the wiring conductor
5 and cover the periphery of the connection pad 2 and open the center.
Exposed by the opening 8 and covers the wiring conductor 5
An insulating protective layer 3 is provided, and the insulating protective layer 3
If you use an organic insulating material such as epoxy resin or polyimide,
Good, but a high frequency signal is applied to the connection pad 2 and the wiring conductor 5.
From the viewpoint of transmission, especially high-frequency signals such as 10 GHz or more
In order to reduce the transmission loss of a signal,
It is desirable to use an insulating material having an electric conductivity of 4 or less. Ma
The insulating protective layer 3 is made of alumina ceramic or glass
An inorganic insulating material such as Lamix may be used.
Can achieve the same effect. The non-forming portion 6 is provided on the insulating protective layer 3 and arranged.
When exposing the wire conductor 5, the shape of the non-formed portion 6 is
FIG. 1 shows that the wire conductor 5 can maintain constant electrical characteristics.
To expose the wiring conductor 5 as a shape along the wiring conductor 5
It is desirable to make it. In addition, the shape of the non-formed portion 6 is a wiring
With a different shape that is not parallel to the conductor 5 but gradually spreads
FIG. 2 is a perspective view similar to FIG.
A plurality of adjacent wiring conductors together with the wiring conductor 5
(Not shown) from the opening 8 on the connection pad 2
From the position of (2n-1) / 4 times the frequency signal
A wide non-forming portion 6a that exposes
You may. In addition, prevention of mismatch of characteristic impedance
From the viewpoint of suppressing the reflection noise and reflection noise.
High-frequency signal wave transmitted from the opening 8 by the wiring conductor 5
Cover the wiring conductor 5 to the position of 1/4 of the length.
So that the wiring conductor 5 at the end is exposed therefrom.
It is desirable to provide the non-formed portions 6, 6a in the insulating protective layer 3.
However, for example, wiring for transmitting a high-frequency signal of 5 to 10 GHz
For the conductor 5, (2n-1) /
Insulation protection on the wiring conductor 5 in the portion beyond the four-fold length
Non-forming portions 6 and 6a are provided in the protective layer 3 to expose the wiring conductor 5.
To prevent characteristic impedance mismatch and reflection.
For noise suppression, etc.
it can. In the wiring board 1 of the present invention, the insulating protective layer
Reference numeral 3 denotes the wavelength of the high-frequency signal from the opening 8 on the connection pad 2.
(2n-1) / 4 (n is a natural number)
It is important to coat the wire conductor 5. This is not covered with the insulating protective layer 3
From the portion 8 of the wiring conductor 5 and the opening 8 on the connection pad 2
Up to a position (2n-1) / 4 times the wavelength of the wave signal
Reflected waves generated at the connection point with the coated part,
From the opening 8 on the connection pad 2, the wavelength (2) of the high-frequency signal
(n-1) / 4 times as long as the part covered
The reflected wave generated at the connection point with the connection pad 2 is
In the portion of the wiring conductor 5 not covered with the edge protection layer 3
Cancel each other out by inverting the phase by 180 °
Impedance mismatch due to equal reflection coefficient
Can be effectively suppressed and high frequency signals can be passed smoothly.
Because you can do it. The wiring board 1 is, for example, a microprocessor
If the wiring board is mounted with
For the clock signal that is not
-1) Insulating protective layer 3 in a portion beyond the position of / 4 times length
The wiring conductor 5 is exposed by providing a non-formed portion 6
Low-frequency signals such as data signals and address signals
A similar non-formed portion 6 is provided for the wiring conductor 5 to be exposed.
You can leave it out. Opening 8 of insulating protective layer 3 on connection pad 2
Is the same as the shape of the connection pad 2,
In addition to the circular shape shown, square, rectangular,
Diamond, hexagonal or octagonal shapes and other irregular shapes
The connection pad 2 inside the opening 8
The flow of solder and other components on the
Nose electrode and connection pad 2 are firmly joined and connected well
In order to achieve this, it is desirable to have a circular shape. Ma
In addition, the size of the connection pad 2 and the opening 8 depends on the characteristic impedance.
The size is such that the dance matches the wiring conductor 5
It is desirable to set as follows. Here, one of the conventional wiring boards is described.
An example is shown in a perspective view similar to FIG.
This will be described in detail. In FIG. 3, 21 is a wiring board, and 24 is an insulating substrate.
It is an insulating resin layer as a plate, and
A connection pad 22 and a wiring conductor 25 derived therefrom are formed.
Ground conductor or power conductor 27 on the back
Being shielded. A connection pad made of a metal conductor such as copper
Air around the wiring conductors 25 and around the wiring conductors 25
An insulating protective layer 23 for preventing oxidation of the body covers them.
Formed over almost the entire surface of the insulating resin layer 24 so as to cover it
Have been. Therefore, the relative permittivity of the wiring conductor 25 is
An insulating protective layer 23 made of a high insulating material is interposed.
Thus, the high-frequency signal transmitted by the wiring conductor 25
, A signal delay occurs. The wiring conductor 25 has an insulating material that covers it.
The surface is roughened to improve the adhesion to the edge protection layer 23.
In this conventional wiring board 21, the wiring conductor
Since the entire surface of 25 is covered with the insulating protective layer 23, the wiring conductor
Roughening treatment will be performed on the entire surface of 25. As a result,
Process results in the formation of irregularities on the conductor surface of the wiring conductor 25.
In particular, the effect of the skin effect is particularly significant when operating high-frequency signals.
Because of its large size, high frequency signal
Signal delay and noise are likely to occur. Further, an IC chip mounted on the wiring board 21 is provided.
The integration of high-frequency electrodes for IC chips
In response to the narrowing of the electrode terminals, wiring
The width of the wiring on the substrate 21 has also become smaller,
The characteristic impedance based on the comparison between 25 wiring width and thickness is
A power supply conductor layer and a ground conductor layer facing each other at a predetermined distance
Wiring is matched by the electromagnetic coupling of
As the width becomes narrower, the insulating resin layer 24,
The thickness of the protective layer 23 also becomes thinner, and the wiring conductor becomes more prominent.
Form a stable thickness under the influence of unevenness due to 25
And it is becoming difficult. On the other hand, if the IC chip is a multiplexer or
It has functions such as a multiplexor and multiplexes low-frequency signals.
Output as a high-frequency signal by
A large number of low frequency signals of 1 GHz or less and 10
Must transmit a small number of high-frequency signals above GHz
Absent. However, in the conventional wiring board 21, the air
Insulation protective layer formed of insulating material such as oxy resin
The thickness of 23 affects the unevenness of the wiring conductor 25 and uneven width.
It is difficult to make it uniform because of the influence. That
Therefore, matching of the characteristic impedance in the wiring conductor 25 is not performed.
High frequency signal multiplexed by IC chip
There is a problem that transmission loss is large when transmitting
Was. Further, for example, a microprocessor is mounted.
Clock signal, which is the basic signal,
It becomes a high-frequency signal, but the relative dielectric constant of the insulating protective layer 23 is large.
Therefore, the transmission loss in the wiring conductor 25 is large.
Signal rise time is delayed and the data signal malfunctions.
There is a problem that it is easy to occur. On the other hand, according to the wiring board 1 of the present invention,
For example, as shown in FIG.
From (2n-1) / 4 times the wavelength of the high-frequency signal
Non-formed portion on the insulating protective layer 3 on the wiring conductor 5 in the part beyond
6 is provided, from which the wiring conductor 5 is exposed.
Therefore, the wiring conductor 5 in that portion is insulated with a high relative dielectric constant.
Since it is not covered by the protective layer 3, the transmission of high-frequency signals
Signal delay can be prevented. Further, a non-formed portion 6 is provided in the insulating protective layer 3,
An insulating protective layer 3 is formed on the wiring conductor 5 in that portion.
Therefore, the insulating protective layer 3 is not provided with the wiring conductor 5 as in the prior art.
Has uneven thickness due to the unevenness of
Do not cause characteristic impedance mismatch.
No. Further, for the non-formed portion 6 of the insulating protective layer 3,
Therefore, it is not necessary to perform a roughening treatment on the conductor surface of the wiring conductor 5.
Therefore, the skin resistance of the wiring conductor 5 does not deteriorate,
Has a wiring conductor 5 with small conductor loss for high frequency signals
Wiring board 1 can be obtained. In addition, the wiring conductor 5
Even when the non-formed portion 6 is provided after performing the roughening process,
Nickel plating or gold plating on the exposed surface of the wiring conductor 5
To fill the roughened uneven surface.
Signal with the skin effect that affects the operation of high-frequency signals
Delay and noise can be effectively prevented. Also, electronic components are mounted on the connection pads 2.
When connecting high-frequency signal electrodes with solder, etc.
The opening of the insulating protective layer 3 exposing the connection pad 2
8 and (2n-1) / 4 times the wavelength of the high-frequency signal
The wiring conductor 5 is covered between the placement and the previous non-formed portion 6.
Connection insulating pad 3
2. Prevents the flow of solder or the like from 2 into the wiring conductor 5
High-frequency signal transmitted by the wiring conductor 5
Noise caused by characteristic impedance mismatch
Noise can be suppressed efficiently. Then, such a wiring board 1 of the present invention
Is a package for storing electronic components such as a package for storing semiconductor elements.
Package, electronic component mounting board, and many semiconductor elements.
So-called multi-chip module or multi-chip
Package, or used as a motherboard
You. In the wiring board 1 of the present invention, the insulating substrate
Each insulating resin layer 4 is made of, for example, polyimide or epoxy resin.
Fat, fluororesin, polynorbornene or benzocyclo
It is formed using an organic insulating material such as butene. Also
Uses an inorganic resin powder such as ceramic powder
Of composite insulating material etc.
It is formed using a gas insulating material. The insulating substrate made of these insulating resin layers 4 is as follows.
It is produced as follows. For example, made of epoxy resin
In general, aluminum oxide-based sintered bodies
Epoxy on cloth woven from ceramics and glass fibers
Glass epoxy resin or the like formed by impregnating resin
Organic resin precursor is spin-coated on the upper surface of the insulating layer made of
Applied by a coating technique such as
And heat-curing it to form an epoch.
An insulating resin layer 4 made of an organic resin such as a xy resin is obtained. Next
In addition, thin film forming technologies such as electroless plating and vapor deposition of copper
And wiring by adopting photolithography technology
The conductor 5 and the connection pad 2 are formed. And obtained
The insulating resin layer 4 and the wiring conductor 5 are alternately laminated,
By heating and curing at a temperature of about
The wiring board 1 is manufactured as a plate. Further, for example, inorganic powders such as ceramic powders may be used.
The edge powder is bonded with a thermosetting resin such as epoxy resin.
If it is an electrical insulating material such as a composite insulating material,
Varnish-like resin such as epoxy resin
A slurry is formed by adding and mixing an insulating powder and a solvent. this
The sheet is formed by adopting the well-known doctor blade method.
By doing so, the sheet in the B stage state (semi-cured state)
To get Then, a metal foil to be each wiring conductor 5 is laminated.
After curing, the specified pattern is etched
Formed, and the sheets in the B-stage state are stacked up and down,
Finally, an epoxy resin or the like to be the insulating protective layer 3 is applied.
A portion where a predetermined insulating protective layer 3 is not formed by light and development
After setting 6, heat curing at a temperature of 160 to 200 ° C
Produced by The thickness of these insulating resin layers 4 is
Corresponds to the required specifications according to the characteristics of the material used
Appropriately installed to satisfy conditions such as mechanical strength and electrical characteristics
Is determined. Each wiring conductor 5 and connection pad 2
Are, for example, copper (Cu), silver (Ag), nickel (N
i), chrome (Cr), titanium (Ti), gold (Au)
Or thin films of metallic materials such as niobium (Nb) and their alloys
Etc. may be used. Specifically, for example, a thin film of a metal material is formed.
When using sputtering, vacuum deposition or mesh
After a metal film is formed by the
To form a predetermined wiring conductor 5 and connection pad 2
be able to. The present invention is limited to the above embodiment.
It is not specified and does not deviate from the gist of the present invention.
Various changes can be made in. example
For example, the shape of the non-formed portion 6 is not parallel to the wiring conductor 5 but arranged.
It becomes gradually thinner as long as it does not cover the wire conductor 5.
Is also good. According to the wiring board of the present invention, the insulating substrate
Connections to which high-frequency signal electrodes of electronic components are connected on the surface
Pads and high-frequency signals derived from these connection pads
Conductor for transmitting the
And an insulating protective layer covering the periphery of the pad.
The insulating protective layer is used to transmit a high frequency signal from the opening on the connection pad.
(2n-1) / 4 times (n is a natural number) wavelength
To cover the wiring conductor up to
Since the wiring conductor is exposed,
The dielectric constant on the conductor is as small as the relative dielectric constant of air is 1.
And formed of epoxy resin and other materials.
Wiring conductor formed on the underlayer with the thickness of the insulating protection layer
Due to unevenness due to unevenness due to
If it adversely affects the characteristic impedance matching
The shadow of geometric dimensional change that results in fluctuation
The sound can be eliminated. As a result, disconnection from the wiring conductor
It goes around the edge protection layer and is connected to the power supply conductor layer and the ground conductor layer.
Electromagnetic coupling can be stabilized.
Impedance does not change.
The characteristic impedance of the wiring conductor
The occurrence of alignment can be effectively prevented. Also, electronic parts and the like are mounted on the connection pads.
When joining with solder, etc., keep the insulation on the connection pads.
(2n-1) / 4 of the wavelength of the high-frequency signal from the opening of the protective layer
Wiring conductors up to double the length are covered with an insulating protective layer.
Prevents the flow of solder or other liquid onto the wiring conductor.
It can be stopped, so that solder etc. flows into the wiring conductor
Resulting from the characteristic impedance mismatch
And efficiently suppress high frequency signal reflection noise
Can be. As a result, according to the present invention, the high-frequency signal
The mismatch of characteristic impedance in wiring conductors
And a low frequency signal in the GHz band.
Low transmission loss even when transmitting high-frequency signals
Structure of the insulating protective film, which is less likely to cause signal delay and signal error.
Electronic components such as semiconductor devices that operate at high speed
To provide a wiring board suitable for an electronic circuit board to be mounted.
I was able to.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view showing an example of an embodiment of a wiring board of the present invention. FIG. 2 is a perspective view showing another example of the embodiment of the wiring board of the present invention. FIG. 3 is a perspective view showing an example of a conventional wiring board. [Description of Signs] 1 ・ ・ ・ Wiring board 2 ・ ・ ・ Connection pad 3 ・ ・ ・ Insulating protective layer 4 ・ ・ ・ Insulating resin layer (insulating substrate) 5 ・ ・ ・ Wiring conductors 6 and 6a ・ ・ ・ Non-formed part 7: ground conductor, power supply conductor 8: opening L: length of (2n-1) / 4 times wavelength of high frequency signal

Claims (1)

Claims: 1. A connection pad to which a high-frequency signal electrode of an electronic component is connected on a surface of an insulating substrate, a wiring conductor for transmitting a high-frequency signal derived from the connection pad, and the wiring A conductor and an insulating protective layer covering a peripheral portion of the connection pad are formed, and the insulating protective layer is (2n-1) / 4 times the wavelength of the high-frequency signal (n is a natural number) from an opening on the connection pad. A) the wiring conductor is covered to a position corresponding to the length of the wiring substrate, and the wiring conductor is exposed from the wiring conductor;