CN107241855B - A kind of wiring board with shielding construction - Google Patents
A kind of wiring board with shielding construction Download PDFInfo
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- CN107241855B CN107241855B CN201710683973.3A CN201710683973A CN107241855B CN 107241855 B CN107241855 B CN 107241855B CN 201710683973 A CN201710683973 A CN 201710683973A CN 107241855 B CN107241855 B CN 107241855B
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- layer
- shielding
- wiring board
- insulating layer
- secondary shielding
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Classifications
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- H—ELECTRICITY
- H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
- H05K—PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS
- H05K1/00—Printed circuits
- H05K1/02—Details
- H05K1/0213—Electrical arrangements not otherwise provided for
- H05K1/0216—Reduction of cross-talk, noise or electromagnetic interference
-
- H—ELECTRICITY
- H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
- H05K—PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS
- H05K3/00—Apparatus or processes for manufacturing printed circuits
- H05K3/0011—Working of insulating substrates or insulating layers
-
- H—ELECTRICITY
- H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
- H05K—PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS
- H05K2201/00—Indexing scheme relating to printed circuits covered by H05K1/00
- H05K2201/07—Electric details
- H05K2201/0707—Shielding
-
- H—ELECTRICITY
- H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
- H05K—PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS
- H05K2203/00—Indexing scheme relating to apparatus or processes for manufacturing printed circuits covered by H05K3/00
- H05K2203/12—Using specific substances
Abstract
The present invention provides a kind of wiring board with shielding construction, the wiring board includes first screen layer, secondary shielding layer, line layer setting between first screen layer and secondary shielding layer, first insulating layer is set between line layer and first screen layer, second insulating layer is set between line layer and secondary shielding layer；It is slightly less than line layer in secondary shielding layer and second insulating layer setting line layer and in size, when secondary shielding layer and second insulating layer are covered on line layer, multiple metal electrodes for being connected with external circuit at least are set in the exposed edge portions on one side along partial denudation outside secondary shielding layer on line layer.Using technical solution of the present invention, shielded layer is all arranged by the two sides in line layer, without carrying out shielding processing to route using screening cover；It is directly exposed outside insulating layer by the metal electrode for being used to connect by line layer, the generation of parasitic capacitance is avoided, the anti-interference function of circuit board is greatly improved.
Description
The application is application No. is the divisional application of 2015105227548 patent application, and the applying date of female case is 2015
On August 24, a kind of denomination of invention are as follows: wiring board and preparation method thereof with shielding construction.
Technical field
The present invention relates to printed circuit board technology field more particularly to a kind of wiring boards with shielding construction.
Background technique
Some special application fields of assist side, for example, it is remote sensing satellite, aerospace, radar communication, high frequency antenna, micro-
The applications such as wave antenna, stability and anti-interference to wiring board require extremely harshness, in complexity such as very high temperature, extremely low temperature
Under environment, wiring board will keep stability；Any faint interference signal is likely to influence the normal work of wiring board,
It is thus typically necessary to carry out shielding processing to wiring board.The prior art generallys use welding metal screening cover in assist side and comes
The interference free performance of wiring board is promoted, metallic shield lid needs to weld under high temperature, increases one of process, not only increase
The complexity of processing technology, while it being be easy to cause in high-temperature soldering the softening of wiring board material, wiring board can generate certain
Deformation, and screening cover pyroconductivity and electronic circuit board comparing difference are larger, and screening cover heating is very fast, will result in screen in this way
The leading warpage of lid is covered, to influence electronic circuit board contour structures and cause other devices rosin joint.For example, Chinese patent literature
[201110199763.X] discloses the welding method of a kind of screening cover and electronic circuit board, solves wiring board and is crossing reflow ovens
When lead to the problem of warpage, can effectively reduce production cost.
Above-mentioned technical proposal solves the problems, such as that wiring board generates warpage when crossing reflow ovens, improves to a certain extent
Production technology, but still need using metallic shield lid, welding metal screening cover will affect line to a certain extent at high temperature
The performance of component on the plate of road.
Therefore for drawbacks described above present in currently available technology, it is really necessary to be studied, to provide a kind of scheme,
Solve defect existing in the prior art.
Summary of the invention
In view of this, the purpose of the present invention is to provide a kind of wiring boards with shielding construction, to solve the above problems.
In order to solve problems in the prior art, the technical solution of the present invention is as follows:
A kind of wiring board with shielding construction, the wiring board include first screen layer (1), secondary shielding layer (5), setting
Line layer (3) between the first screen layer (1) and the secondary shielding layer (5), in the line layer (3) and described
First insulating layer (2) are set between one shielded layer (1), is arranged between the line layer (3) and the secondary shielding layer (5)
Two insulating layers (4)；
The material of first insulating layer (2) is ceramic base material, epoxy glass fiber cloth, glass honeycomb core plate, polyamides Asia
Any one of amine foam substrate；
The material of the second insulating layer (4) is elastic insulating material；
The secondary shielding layer (5) and the second insulating layer (4) are arranged on the line layer (3) and are slightly less than in size
The line layer (3), when the secondary shielding layer (5) and the second insulating layer (4) are covered on the line layer (3),
On the line layer (3) at least on one side along part (6) it is exposed the secondary shielding layer (5) outside, in the exposed edge portions (6)
Multiple metal electrodes (7) for being connected with external circuit are set；
The circumferential direction of the wiring board is additionally provided with multiple exposed semicircle connections via hole (8), and the connection via hole (8) is for connecting
Lead to the first screen layer (1) and the secondary shielding layer (5)；
The line layer (3) is indium tin oxide films layer, is formed on circuit diagram by photoresist mask etch technique
Shape simultaneously directly forms resistive element on the circuitous pattern.
Preferably, circuitous pattern is formed on the line layer (3), the circuitous pattern includes for realizing circuit function
Main circuit figure and metal electrode (7) for being connected with external circuit.
Preferably, component is mounted on the circuitous pattern and forms intermediate wiring board.
Preferably, keep the metal electrode (7) of the circuitous pattern exposed outside and the main electricity by precision machinery processing
Road figure is completely encapsulated between the first screen layer (1) and the secondary shielding layer (5).
Preferably, connection via hole (8) the coating silver paste makes the connection via hole (8) be connected to the first screen layer (1)
With the secondary shielding layer (5).
Preferably, the first screen layer (1) and the secondary shielding layer (5) use copper foil.
Preferably, the first screen layer (1) and the secondary shielding layer (5) by first insulating layer (2) or
The mode that silver-bearing copper composite shielding coating is coated on the second insulating layer (4) is formed.
Preferably, the silver-bearing copper composite shielding coating the preparation method comprises the following steps:
A graininess copper powder is provided, the diameter of the copper powder particle is less than 50 microns；
Silver-coated layer, which is applied, on the copper powder particle surface forms wicker copper particle powder；
Wicker copper particle powder is dissolved in resin combination adhesive, the resin combination adhesive includes epoxy
Resin, polyurethane, phenolic aldehyde, polyimides and acrylic resin；
Being stirred continuously is evenly distributed on wicker copper particle powder in resin combination adhesive, forms silver-bearing copper composite shielding
Coating.
Preferably, the volume ratio range of the wicker copper particle powder and the resin combination adhesive be 1.1 to
1.8。
Preferably, the silver-bearing copper composite shielding coating by high-pressure spray gun even application in first insulating layer (2) and
The second insulating layer (4), then be dried to form the first screen layer (1) and described second by thermostatic drying chamber
Shielded layer (5)；
In spraying process, the silver-bearing copper composite shielding coating is kept stirring by magnetic stirrer.
Compared with the existing technology, the wiring board of shielding construction provided by the invention, by being all arranged on the two sides of line layer
Shielded layer, without carrying out shielding processing, since shielded layer and line layer are integrated, processing side to route using screening cover
Just and the performance of component on line layer will not be influenced because shielding process is increased；Pass through the metal for being used to connect by line layer
Electrode is directly exposed outside insulating layer, will draw connection metal electrode without processing via hole in assist side and be connected to route
Plate surface avoids the generation of parasitic capacitance, greatly improves the anti-interference function of circuit board；The circumferential direction of assist side is set simultaneously
Multiple exposed connection via holes are set, so that upper and lower shielded layer is become equipotentiality body, further promotes the shielding properties of wiring board.
Detailed description of the invention
Fig. 1 is the structural block diagram of the wiring board provided by the invention with shielding construction.
Fig. 2 is the facing structure block diagram for the wiring board with shielding construction that the embodiment of the present invention 1 provides.
Fig. 3 is the facing structure block diagram for the wiring board with shielding construction that the embodiment of the present invention 2 provides.
The step of Fig. 4 is the wiring board preparation method with shielding construction provided by the invention is schemed.
Fig. 5 is coating surface when shielding coating amplifies 500 times in the secure execution mode (sem.
Fig. 6 is coating surface when shielding coating amplifies 1000 times in the secure execution mode (sem.
Fig. 7 is the energy spectrum diagram under shielding coating EDS.
In above-mentioned attached drawing, wherein first screen layer 1, the first insulating layer 2, line layer 3, second insulating layer 4, secondary shielding
Layer 5, line layer edge portions 6, metal electrode 7 connect via hole 8.
Specific embodiment
Following is a specific embodiment of the present invention in conjunction with the accompanying drawings, technical scheme of the present invention will be further described,
However, the present invention is not limited to these examples.
Fig. 1 and Fig. 2 are please referred to, the structural block diagram of the wiring board provided by the invention with shielding construction is shown, it is a kind of
Wiring board with shielding construction, including first screen layer 1, secondary shielding layer 5, setting are in the first screen layer 1 and described
The first insulating layer 2 between the line layer 3 and the first screen layer 1 is arranged in line layer 3 between secondary shielding layer 5,
Second insulating layer 4 between the line layer 3 and the secondary shielding layer 5 is set；
The secondary shielding layer 5 and the second insulating layer 4 are arranged on the line layer 3 and are slightly less than the line in size
Road floor 3, when the secondary shielding layer 5 and the second insulating layer 4 are covered on the line layer 3, the line layer 3 up to
Few edge portions 6 are exposed outside the secondary shielding layer 5, and multiple be used for and external circuit is arranged in the exposed edge portions 6
The metal electrode 7 being connected.
Technical solution of the present invention uses three-decker, by the way that shielded layer is all arranged on the two sides of line layer 3, without adopting
Shielding processing is carried out to route with screening cover, shielded layer is integrated with line layer, it is easy to process and will not because of increase shield
Technique influences the performance of component on line layer.
The line layer of wiring board in the prior art simultaneously, middle layer will connect with lower circuit thereon or outside line
It connects, generallys use the mode for processing metallic vias in assist side, due to formation metal layer inside metallic vias, can generate in this way
Parasitic capacitance.The presence of this parasitic capacitance makes traditional circuit plate be unable to satisfy application in the application of some high requests
It is required that.Technical solution of the present invention is directly exposed outside insulating layer by the metal electrode 7 for being used to connect by line layer 3, thus
Connection metal electrode 7 will be drawn without processing via hole in assist side and be connected to PCB surface, and avoid the generation of parasitic capacitance,
Greatly improve the anti-interference function of circuit board.
In the above-mentioned technical solutions, the material of first insulating layer 2 is ceramic base material, epoxy glass fiber cloth, glass
Any one of honeycomb core plate, polyimide foam substrate；Epoxy glass fiber cloth and ceramic base material are that the prior art is common
Board substrate, epoxy glass fiber cloth wiring board and ceramic base circuit board are relatively conventional in general circuit application field.One
A little special applications, generally use performance more preferably glass honeycomb core plate and polyimide foam substrate.Polyimides bubble
Foam material is resistant to 250 DEG C~300 DEG C of temperature, is resistant to 400 DEG C~500 DEG C high temperature in short-term, and have good mechanicalness
(for tensile strength in 100MPa or more), elasticity modulus is usually 3GPa~4GPa to energy, can be used as load structure in the high temperature environment
Part uses, and meets the needs of industry such as Aeronautics and Astronautics and electronics.Polyimide foams have very high radioresistance
Can, after 5 × 109rad dose delivery, intensity still keeps 80% or so, and has good dielectric properties, and dielectric constant is
3.4 or so, Polyimide foams dielectric loss is 10-3, and dielectric strength is 100kV/mm~300kV/mm, volume resistance
Rate is the 1017 Ω cm orders of magnitude, and the copper-clad plate that these performances prepare polyimide foam base is in wide temperature range
With higher level is still able to maintain in frequency range, make it in spies such as remote sensing satellite, aerospace, microstrip antenna, high frequency antennas
There is unrivaled performance advantage in different application.Glass honeycomb core plate has glass honeycomb sandwich construction, higher with having
Strength and stiffness and quality it is lighter, compared with the epoxy glass-fiber-fabric circuit board, weight saving 80% has very high than strong
Degree, specific stiffness, flatness is good, is unlikely to deform, and structure is simple, easy for installation.It is preferably carried out in mode in one kind, the first insulation
Layer 2 uses glass honeycomb core plate or polyimide foam substrate.
Due to being additionally provided with component on line layer 3, second insulating layer 4 need to cover the component on line layer 3, therefore
Two insulating layers 4 need certain deformation space, select elastic insulating material.Preferably, second insulating layer 4 uses elastic insulated rubber
Glue.
Referring to Fig. 3, it is shown the facing structure block diagram of the wiring board with shielding construction of the offer of the embodiment of the present invention 2,
The circumferential direction of the wiring board is additionally provided with multiple exposed semicircle connection via holes 8, and the connection via hole 8 is for being connected to first screen
Layer 1 and the secondary shielding layer 5 are covered, so that upper and lower shielded layer is become equipotentiality body, further promotes the shielding properties of wiring board.Simultaneously
Since connection via hole 8 is exposed outside, without forming connection via hole 8 in assist side, the generation of parasitic capacitance is avoided, further
Improve the anti-interference function of circuit board.
In a preferred embodiment, line layer 3 uses copper foil, further, after forming circuitous pattern on copper foil,
It is adhered by the first insulating layer 2.
In a preferred embodiment, line layer 3 is indium tin oxide films layer, and the effect of indium tin oxide films layer is similar
Copper foil is formed on circuitous pattern by photoresist mask etch technique.Indium tin oxide films layer has electricity conduction simultaneously
Characteristic and good shielding properties, in the prior art as EMI shielding conduction plated film be widely used.In the present invention, directly
Circuitous pattern is formed using indium tin oxide films layer, further promotes the shielding properties of wiring board.
Further, in some special dimensions, in order to guarantee the stability of wiring board, in the circuitous pattern of line layer 3
It is upper directly to form resistive element.Such as in microstrip circuit or high frequency antenna, the resistive element of use is more, using the prior art
Resistive element, consistency and stability it is difficult to ensure that, while minor change can also occur for resistance welding procedures its resistance values.At this
In inventive embodiments, due to forming line layer 3 using indium tin oxide material, the resistivity of tin indium oxide is much larger than the metals such as copper,
Therefore resistance can be set on direct-on-line road floor 3 when forming circuitous pattern.Actual resistance figure can be according to indium oxide
The resistivity of tin material is calculated.I.e. in the resistive element position of line pattern, sunk in the preparation according to the size of its resistance value
Product resistance pattern corresponding with its resistance value.
In a preferred embodiment, first screen layer 1 and secondary shielding layer 5 use copper foil, and metal is natural screen
Body is covered, line layer 3 is wrapped in copper foil layer up and down, shield effectiveness can be played.
But since the copper atom of these high activities of copper foil surface is easy to be oxidised with air to Cu2The film of O and CuO, especially
The big oxidization of copper powder speed of its surface area faster, greatly reduces shielding properties.In a preferred embodiment, using
The mode of one insulating layer 2 and 4 surface of second insulating layer spraying silver-bearing copper composite shielding coating forms first screen layer 1 and secondary shielding
Layer 5.Silver is to be used as conductive filler in all metals earliest, the conductive good (ρ of energyv=1.62 × 10-6Ω cm), it is anti-
Oxidability is strong, steady performance, but silver is under Dc bias effect, or under wet heat condition, is easy to happen migration and leads
Short circuit is caused, the safety coefficient of application is substantially reduced.In addition, the price of silver is expensive compared with copper very much, will be made using silver as shielded layer
Cost greatly improves.Due to being blended in resin after forming silver-coated copper powder in silver-bearing copper composite shielding coating, copper powder is not and outside
Boundary directly contacts, and improves the antioxygenic property of copper powder, while obtaining the electric conductivity close to silver, and in cost with use
Copper foil is similar.
Of the existing technology in order to solve the problems, such as, the present invention also provides a kind of systems of wiring board with shielding construction
Preparation Method, referring to fig. 4, the step of showing as the wiring board preparation method with shielding construction provided by the invention figure, including
Following steps:
Step S1: the first insulating layer 2 is provided and forms first screen layer 1 in 2 one side of the first insulating layer；
Step S2: being arranged a line layer 3 in 2 another side of the first insulating layer and form circuitous pattern on the line layer 3,
The circuitous pattern includes the metal electrode for realizing the main circuit figure of circuit function and for being connected with external circuit
7；
Step S3: component is mounted on the circuitous pattern with SMT technique, forms intermediate wiring board；
Step S4: second insulating layer 4 is provided and forms secondary shielding layer 5 in 4 one side of second insulating layer；
Step S5: one layer of semi-liquefied resin is set in the another side of second insulating layer 4；
Step S6: before the semi-liquefied resin solidification, the intermediate wiring board is had to the one side of line pattern
It is placed on the semi-liquefied resin, and presses the intermediate wiring board until the semi-liquefied resin under certain pressure effect
It is fully cured；
Step S7: keep the metal electrode 7 of the circuitous pattern exposed outside and the main circuit by precision machinery processing
Figure is completely encapsulated between the first screen layer 1 and the secondary shielding layer 5.
The wiring board prepared using the above method, since shielded layer is all arranged on the two sides of line layer 3, without using
Screening cover carries out shielding processing to route, simplifies preparation process and will not influence on line layer 3 because shielding process is increased
The performance of component；By by line layer 3 be used for connect metal electrode 7 directly it is exposed outside insulating layer, without
Processing via hole, which will draw connection metal electrode 7, in wiring board is connected to PCB surface, avoids the generation of parasitic capacitance, mentions significantly
The anti-interference function of circuit board is risen；
In above-mentioned steps S1 and step S4, using copper foil as the first screen layer 1 and the secondary shielding layer 5.But
Since the copper atom of these high activities of copper foil surface is easy to be oxidised with air to Cu2The film of O and CuO, especially surface area are big
Oxidization of copper powder speed faster, greatly reduce shielding properties.In a preferred embodiment, by first insulation
The mode that silver-bearing copper composite shielding coating is coated on layer 2 or the second insulating layer 4 forms the first screen layer 1 and described second
Shielded layer 5.
Further, above-mentioned silver-bearing copper composite shielding coating the preparation method comprises the following steps:
A graininess copper powder is provided, the diameter of the copper powder particle is less than 50 microns；
Silver-coated layer, which is applied, on the copper powder particle surface forms wicker copper particle powder；
Wicker copper particle powder is dissolved in resin combination adhesive；
Being stirred continuously is evenly distributed on wicker copper particle powder in resin combination adhesive, forms silver-bearing copper composite shielding
Coating.
In above-mentioned steps, the resin combination adhesive include epoxy resin, polyurethane, phenolic aldehyde, polyimides and
Acrylic resin；Most of physical property of resin base-material decision coating.Many Fundamental Physical Properties of shielding coating and common
Coating is identical, such as: adhesive force, adherence, wearability and resistance to scraping etc..These performances are mainly by matrix resin and auxiliary
Resin shared.Coating is applied to surface of insulating layer, it is desirable that the adhesive strength of coating is high, shielding coating has stronger cohesion
Power.Coating based on thermoplastic resin ester group adhesive is influenced unlike two-component coating by construction and baking temperature,
The activation time limit not used.
Further, it applies in the step of silver-coated layer forms wicker copper particle powder on the copper powder particle surface, first uses
Inhibitors On Copper powder is handled, such as with organic acid, organic titanium corrosion inhibiter；Again anti-using silver mirror commonly used in the prior art
Should be silver-plated in Copper Powder Surface, form silver-coated copper powder.
The shielding properties (namely electric conductivity, determined by resistance of coating value height) and silver-coated copper powder of shielding coating are (i.e. following
Conductive filler) itself resistance value it is related, and concentration of the conductive filler in shielding coating is similarly important.How to be shielded
Cover the design of formulation for coating material so that shielding coating there should be good electric conductivity, and have good physical property, each material group
For the fixing fabric structure divided just at the key of formula design, the volume ratio of especially conductive material and adhesive has relationship.Passing through
Repetition test and test, the results showed that, when the volume ratio of conductive material and adhesive is less than 1, the surface of conductive particle is complete
It being covered entirely by resin binder, almost without good electrical contact between particle, shielding coating cannot embody good electric conductivity,
Cause shielding properties bad.When the volume ratio of conductive material in coating is much larger than the volume of adhesive, partially electronically conductive particle
Outside, binder resin is not enough to fill up void among particles surface exposure, causes the compactness of shielding coating is too low (to have air
In the presence of), it easily loses powder, surface roughness is excessive, easily remains various dirts, is greatly reduced in terms of physical property.Pass through reason again below
By the volume ratio for calculating analysis conductive material and adhesive.The volume of the volume of conductive material and coating in coating is indicated with P
Than reflecting that the proportion relation of coating, formula are expressed as follows with P:
P=Va/(Va+Vb)
=(ma/ρa)/[(ma/ρa)+(mb/ρb)]
=ma/[ma+mb×(ρa/ρb)]
=1/ [1+ (mb/ma)×(ρa/ρb)]
In formula, Va is the volume of conductive material in formula；VbFor the volume of non-conducting material in formula；maTo be led in formula
The quality of electric material；mbFor the quality of non-conducting material in formula；ρaFor the density of conductive material in formula；ρbIt is non-in formula
The density of conductive material.After being formulated determining, ρ a and ρ b are constant.Enable k=ρa/ρb, x=mb/maWherein, k is constant, and x is to become
Amount.Then the expression formula of P can simplify are as follows: P=1/ (1+kx)=(1+kx) -1.By the knowledge of exponential function it is found that P and x value exist
Reference axis first quartile has one-to-one relationship, it is possible to the m in formulab/maTo reflect the variation of P.For coating, m is
It is the quality of conductive filler.Influence of the P to conductivity can turn to be considered as m in formulab/maInfluence to conductivity.When adhesive is
More than one when, Vb、mbAnd ρbRespectively represent the volume, quality and density of mixed resin.
On the basis of theory analysis, in conjunction with experimental results, in a preferred embodiment, wicker copper
The volume ratio range of grain powder and resin combination adhesive is 1.1 to 1.8, in the embodiment of the present invention, the volume ratio used for
1.5。
Referring to Fig. 5, Fig. 6, Fig. 7, it show silver when the volume of wicker copper particle powder and resin combination adhesive is 1.5
Copper composite shielding coating observes coating surface figure, Cross Section Morphology figure and energy spectrum diagram under scanning electron microscope.Uniformly mixed coating
Even application after solidification to be dried, observes coating surface and Cross Section Morphology, such as on pmma substrate under scanning electron microscope
Shown in Fig. 5 and Fig. 6, picture is shot when amplifying 500 times and 1000 times respectively under 20KV voltage.At 1000 times, Ke Yiguan
That examines is more clear.Conduction pattern of the charge in shielding coating is that particle contact is conductive, is formed and is led to physical contact between particle
Road.This electrically conducting manner determines two key factors for influencing electric conductivity: first is that interparticle contact number, actually
It is the number of conductive path；Second is that interparticle degree of closeness.It can be seen from the figure that being that face connects between the particle of laminated structure
Touching, contact is abundant, and the non-uniform platy particle of size is more advantageous to the raising of electric conductivity.And the aligning property of flakelike powder
It is good, it is not easy to reunite, there is stronger albedo to light.
Fig. 7 is energy spectrum diagram of the shielding coating at ESD, and in figure, horizontal axis is X-ray energy, and the longitudinal axis is x-ray photon number
Spectrogram.It is assured that the type of element according to its energy value, and containing for each element can be determined by the intensive analysis of spectrum
Amount.For the shielding coating of the embodiment of the present invention, its ingredient, and each ingredient institute of quantitative display can be equally determined using energy spectrum diagram
The scale accounted for.Ingredient included in this kind of coating material can be explicitly found out in figure, wherein copper (Cu) is applying
Content in material is most；Carbon (C) content is higher, be because this paper prepared by coating be using organic glass as substrate, it is organic
Contain a large amount of C element in glass, also contains C element in resin based adhesive and organic solvent.Oxygen (O) element is also above-mentioned object
Contained in matter.
Further, shielding coating is coated uniformly on insulating layer in order to realize, it in a preferred embodiment, will
Silver-bearing copper composite shielding coating passes through high-pressure spray gun even application in first insulating layer 2 and the second insulating layer 4, then passes through
Thermostatic drying chamber is dried to form the first screen layer 1 and the secondary shielding layer 5；In spraying process, pass through
Magnetic stirrer keeps stirring the silver-bearing copper composite shielding coating.
When spraying, shielding coating is first kept stirring into painting by magnetic stirrer magnetic stirrer as in container for paint
Shielding coating in material container；Shielding coating in container for paint is passed through spray gun by the high pressure for recycling air compressor to generate,
On even application to insulating layer.Spraying rate and spray area can be adjusted freely, but spray pressure is used no more than highest
Pressure.Preferably, the maximum working (operation) pressure (MWP) of spray head is 0.5~1.5MPa.
Further, in order to realize automation large area even application spray gun is fixed in a preferred embodiment
In on a movable fixture, the movable fixture uniform motion is driven using stepper motor, drives spray gun mobile, meets large area
Spraying requirement.
Further, in the step S7, when second insulating layer 4 is laminated on line layer 3, second insulating layer 4 is complete
All standing line layer 3 is processed a part of edge of removal secondary shielding layer 5 and second insulating layer 4 by precision machinery, makes circuit
Metal electrode 7 in figure is exposed outside, and main circuit figure is still completely covered under second insulating layer 4, and then makes line layer 3
In main circuit figure be completely encapsulated between the first screen layer 1 and the secondary shielding layer 5.
It is relatively high to the required precision of machining using aforesaid way, once machining accuracy is not high, it is easy to failure line
The electrograph figure of road floor 3.In a preferred embodiment, the first insulating layer 2 is dimensioned to and the line layer 3
Size is adapted, and second insulating layer 4 is dimensioned to be adapted with the size of the main circuit figure, in lamination, is made
The main circuit figure is completely covered in second insulating layer 4, and at least one side is exposed in the secondary shielding along part 6 on line layer 3
Outside layer 5, multiple metal electrodes 7 for being connected with external circuit are set in the exposed edge portions 6.In which, first root
Factually the first insulating layer of dimensioned 2 and second insulating layer 4 of border line layer 3 and its circuitous pattern, so after lamination
It no longer needs to be machined, so that the circuitous pattern of circuit layer will not be destroyed.
Further, line layer 3 is that copper foil further includes steps of in the step S2
Copper foil is printed, etching process, obtains a copper foil with circuitous pattern；
One layer of semi-solid preparation resin is set far from the one side of first screen layer 1 in first insulating layer 2；
The copper foil with circuitous pattern is placed in the surface of the semi-solid preparation resin, forms one to laminate structures, by
The temperature that edges up is until the semi-solid preparation tree is melted, and under certain pressure effect, the copper foil is had being pressed together on for circuitous pattern
The surface of glass dimension honeycomb core plate, then gradually cooling makes first insulation until the semi-solid preparation resin is fully cured
Line layer 3 is formed on layer 2.
In a preferred embodiment, in above-mentioned semi-solid preparation resin curing process, at the uniform velocity to heat up (less than 5 DEG C/min)
50 DEG C to 70 DEG C are warming up to, is cooled down (less than 5 DEG C/min) after resin melts completely, then at the uniform velocity, it is straight under certain pressure effect
It is fully cured to resin.
Further, above-mentioned semi-solid preparation resin or semi-liquefied resin are Epoxy resin composition solution, and difference is
The difference of the matched proportion density of Epoxy resin composition solution.Further, which includes epoxy resin
Composition and the organic solvent that the composition epoxy resin can be dissolved.Composition epoxy resin is by epoxy resin, end amine
The composition of based polyurethanes and inorganic filler composition.
Further, line layer 3 is that indium tin oxide films layer further includes steps of in the step S2
Indium tin oxide films layer is arranged in the first insulating layer 2 using the same steps of above-mentioned copper foil setting on the insulating layer
On；Circuitous pattern is formed on by photoresist mask etch technique.
The effect of indium tin oxide films layer similar to copper foil, the characteristic that there is oxidable indium tin thin film layer electricity to conduct simultaneously and
Good shielding properties, the conduction plated film as EMI shielding is widely used in the prior art.In the present invention, oxidation is directlyed adopt
Indium tin thin film layer forms circuitous pattern, further promotes the shielding properties of wiring board.
Further, further include the steps that directly forming resistive element on the circuitous pattern of line layer 3.Some special
In field, in order to guarantee the stability of wiring board, for example in microstrip circuit or high frequency antenna, the resistive element of use is more,
Using the resistive element of the prior art, consistency and stability it is difficult to ensure that, while resistance welding procedures its resistance values can also occur
Minor change.In embodiments of the present invention, due to forming line layer 3 using indium tin oxide material, the resistivity of tin indium oxide is remote
Greater than metals such as copper, therefore resistance can be set on direct-on-line road floor 3 when forming circuitous pattern.Actual resistance figure can
To be calculated according to the resistivity of indium tin oxide material.I.e. in the resistive element position of line pattern, according to the big of its resistance value
It is small to deposit resistance pattern corresponding with its resistance value in the preparation.Phase is formed by etching and sputtering technology on the resistance pattern
Answer the resistance of resistance value.
It in a preferred embodiment, further include that the circumferential direction of assist side is additionally provided with multiple semicircle connection via holes 8
The step of, and so that the connection via hole 8 is connected to the first screen layer 1 and described second in the connection via hole 8 coating silver paste
Shielded layer 5.Since multiple exposed connection via holes 8 are arranged in the circumferential direction of assist side, upper and lower shielded layer is set to become equipotentiality body, into one
Step promotes the shielding properties of wiring board.
The above description of the embodiment is only used to help understand the method for the present invention and its core ideas.It should be pointed out that pair
For those skilled in the art, without departing from the principle of the present invention, the present invention can also be carried out
Some improvements and modifications, these improvements and modifications also fall within the scope of protection of the claims of the present invention.To these embodiments
A variety of modifications are it will be apparent that the general principles defined herein can be not for those skilled in the art
It is realized in other embodiments in the case where being detached from the spirit or scope of the present invention.Therefore, the present invention is not intended to be limited to this
These embodiments shown in text, and it is to fit to the widest scope consistent with the principles and novel features disclosed herein.
Claims (10)
1. a kind of wiring board with shielding construction, which is characterized in that the wiring board includes first screen layer (1), secondary shielding
Layer (5), the line layer (3) being arranged between the first screen layer (1) and the secondary shielding layer (5), in the line layer
(3) it is arranged between the first screen layer (1) the first insulating layer (2), in the line layer (3) and the secondary shielding layer
(5) second insulating layer (4) are set between；
The material of first insulating layer (2) is ceramic base material, epoxy glass fiber cloth, glass honeycomb core plate, polyimides bubble
Any one of foam substrate；
The material of the second insulating layer (4) is elastic insulating material；
The secondary shielding layer (5) and the second insulating layer (4) are arranged on the line layer (3) and are slightly less than in size described
Line layer (3), it is described when the secondary shielding layer (5) and the second insulating layer (4) are covered on the line layer (3)
On line layer (3) at least on one side along part (6) it is exposed the secondary shielding layer (5) outside, be arranged in the exposed edge portions (6)
Multiple metal electrodes (7) for being connected with external circuit；
The circumferential direction of the wiring board is additionally provided with multiple exposed semicircle connections via hole (8), and the connection via hole (8) is for being connected to institute
State first screen layer (1) and the secondary shielding layer (5)；
The line layer (3) is indium tin oxide films layer, is formed on circuitous pattern simultaneously by photoresist mask etch technique
Resistive element is directly formed on the circuitous pattern.
2. the wiring board according to claim 1 with shielding construction, which is characterized in that formed on the line layer (3)
Circuitous pattern, the circuitous pattern include for realizing the main circuit figure of circuit function and for being connected with external circuit
Metal electrode (7).
3. the wiring board according to claim 2 with shielding construction, which is characterized in that mount member on the circuitous pattern
Device simultaneously forms intermediate wiring board.
4. the wiring board according to claim 2 with shielding construction, which is characterized in that make institute by precision machinery processing
State circuitous pattern metal electrode (7) it is exposed outside and the main circuit figure be completely encapsulated in the first screen layer (1) and
Between the secondary shielding layer (5).
5. the wiring board according to claim 1 with shielding construction, which is characterized in that connection via hole (8) coating
Silver paste makes the connection via hole (8) be connected to the first screen layer (1) and the secondary shielding layer (5).
6. the wiring board according to claim 1 with shielding construction, which is characterized in that the first screen layer (1) and
The secondary shielding layer (5) uses copper foil.
7. the wiring board according to claim 1 with shielding construction, which is characterized in that the first screen layer (1) and
The secondary shielding layer (5) on first insulating layer (2) or the second insulating layer (4) by coating silver-bearing copper composite shielding
The mode of coating is formed.
8. the wiring board according to claim 7 with shielding construction, which is characterized in that the silver-bearing copper composite shielding coating
The preparation method comprises the following steps:
A graininess copper powder is provided, the diameter of the copper powder particle is less than 50 microns；
Silver-coated layer, which is applied, on the copper powder particle surface forms wicker copper particle powder；
Wicker copper particle powder is dissolved in resin combination adhesive, the resin combination adhesive includes asphalt mixtures modified by epoxy resin
Rouge, polyurethane, phenolic aldehyde, polyimides and acrylic resin；
Being stirred continuously is evenly distributed on wicker copper particle powder in resin combination adhesive, forms silver-bearing copper composite shielding and applies
Material.
9. the wiring board according to claim 8 with shielding construction, which is characterized in that the wicker copper particle powder with
The volume ratio range of the resin combination adhesive is 1.1 to 1.8.
10. the wiring board according to claim 8 with shielding construction, which is characterized in that the silver-bearing copper composite shielding applies
Material passes through high-pressure spray gun even application in first insulating layer (2) and the second insulating layer (4), then passes through thermostatic drying chamber
It is dried to form the first screen layer (1) and the secondary shielding layer (5)；
In spraying process, the silver-bearing copper composite shielding coating is kept stirring by magnetic stirrer.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201710683973.3A CN107241855B (en) | 2015-08-24 | 2015-08-24 | A kind of wiring board with shielding construction |
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201510522754.8A CN105101622B (en) | 2015-08-24 | 2015-08-24 | A kind of wiring board with shielding construction and preparation method thereof |
| CN201710683973.3A CN107241855B (en) | 2015-08-24 | 2015-08-24 | A kind of wiring board with shielding construction |
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| CN201510522754.8A Division CN105101622B (en) | 2015-08-24 | 2015-08-24 | A kind of wiring board with shielding construction and preparation method thereof |
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| CN107241855A CN107241855A (en) | 2017-10-10 |
| CN107241855B true CN107241855B (en) | 2019-07-30 |
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| CN201710683973.3A Active CN107241855B (en) | 2015-08-24 | 2015-08-24 | A kind of wiring board with shielding construction |
| CN201510522754.8A Active CN105101622B (en) | 2015-08-24 | 2015-08-24 | A kind of wiring board with shielding construction and preparation method thereof |
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| CN201510522754.8A Active CN105101622B (en) | 2015-08-24 | 2015-08-24 | A kind of wiring board with shielding construction and preparation method thereof |
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| CN208570149U (en) * | 2018-09-13 | 2019-03-01 | 重庆惠科金渝光电科技有限公司 | Insulating coating, soft arranging wire and display device |
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| CN102215630A (en) * | 2010-04-07 | 2011-10-12 | 株式会社藤仓 | Flexible printed board and method of manufacturing same |
| CN102279678A (en) * | 2010-06-12 | 2011-12-14 | 宸鸿科技(厦门)有限公司 | Touch circuit graphic structure, manufacturing method thereof, touch panel and touch display screen |
| CN202121860U (en) * | 2011-06-16 | 2012-01-18 | 湖北奕宏精密制造有限公司 | Flexible circuit board used for precision electronic device |
| CN102559118A (en) * | 2012-02-16 | 2012-07-11 | 莱芜金鼎电子材料有限公司 | High-temperature-resistant conductive adhesive and preparation method thereof |
| CN103687459A (en) * | 2012-09-14 | 2014-03-26 | 昆山雅森电子材料科技有限公司 | Electromagnetic wave shielding structure and flexible printed circuit board with same |
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2011018873A (en) * | 2009-05-22 | 2011-01-27 | Sony Ericsson Mobilecommunications Japan Inc | Electromagnetic shielding method and electromagnetic shielding film |
| CN203721263U (en) * | 2014-03-04 | 2014-07-16 | 吴晶 | High definition security signal transmission line |
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- 2015-08-24 CN CN201510522754.8A patent/CN105101622B/en active Active
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102215630A (en) * | 2010-04-07 | 2011-10-12 | 株式会社藤仓 | Flexible printed board and method of manufacturing same |
| CN102279678A (en) * | 2010-06-12 | 2011-12-14 | 宸鸿科技(厦门)有限公司 | Touch circuit graphic structure, manufacturing method thereof, touch panel and touch display screen |
| CN202121860U (en) * | 2011-06-16 | 2012-01-18 | 湖北奕宏精密制造有限公司 | Flexible circuit board used for precision electronic device |
| CN102559118A (en) * | 2012-02-16 | 2012-07-11 | 莱芜金鼎电子材料有限公司 | High-temperature-resistant conductive adhesive and preparation method thereof |
| CN103687459A (en) * | 2012-09-14 | 2014-03-26 | 昆山雅森电子材料科技有限公司 | Electromagnetic wave shielding structure and flexible printed circuit board with same |
Also Published As
| Publication number | Publication date |
|---|---|
| CN105101622B (en) | 2017-10-03 |
| CN107241855A (en) | 2017-10-10 |
| CN105101622A (en) | 2015-11-25 |
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