CN209462701U - Free ground film and wiring board - Google Patents

Abstract

The utility model embodiment provides a kind of free ground film and wiring board, free ground film includes the first conductor layer, the second conductor layer and adhesive film, and the resin protrusion for being flow to behind the other side by resin from the side of first through hole and solidifying formation is equipped at the first through hole of the first conductor layer；Second conductor layer is set to the first conductor layer close to the side of resin protrusion, to form lug boss in the outer surface of the second conductor layer position corresponding with resin protrusion；Adhesive film is set to side of second conductor layer far from the first conductor layer；When the free ground film is used for the ground connection of printed wiring board, it can mutually be pressed by its adhesive film and the electromagnetic shielding film in printed wiring board, the insulating layer of lug boss puncture adhesive film and electromagnetic shielding film, it is electrically connected with the shielded layer of electromagnetic shielding film, to which effectively the interference charge for accumulating in shielded layer be exported, it avoids the accumulation of interference charge and forms interference source, and then the integrality of signal transmission is effectively ensured.

Description

Free ground film and wiring board

Technical field

The utility model relates to electronic fields, more particularly to a kind of free ground film and wiring board.

Background technique

With the rapid development of electronics industry, electronic product is further to miniaturization, lightweight, assembling densification hair Exhibition greatly pushes the development of flexible electric circuit board, to realize component arrangement and conducting wire connecting integration.Flexible electric circuit board can be wide It is general to be applied to the industries such as mobile phone, liquid crystal display, communication and space flight.

Under the promotion of international market, function flexible electric circuit board is occupied an leading position in flexible electric circuit board market, and is evaluated One important indicator of function flexible electric circuit board performance is electromagnetic shielding (Electromagnetic Interference Shielding, abbreviation EMI Shielding).With the integration of the communication apparatus function such as mobile phone, internal component sharply high frequency High speed.Such as: for cell-phone function other than original audio communication function, camera function has become necessary function, and WLAN (Wireless Local Area Networks, WLAN), GPS (Global Positioning System, the whole world Positioning system) and function of surfing the Net popularized, along with the integration of following sensing component, sharply high-frequency high-speed becomes component Gesture is more inevitable.The component internal and the electromagnetic interference of outside, signal caused under the driving of high frequency and high speed exists Decaying and insertion loss and jitter problem are gradually serious in transmission.

Currently, commonly free ground film generally comprises conductor layer and conductive adhesive layer to existing line plate, conductor layer is by leading Electric glue-line contacts conducting with the shielded layer of electromagnetic shielding film, so that can pass through when printed wiring board is applied to electronic equipment Free ground film is electrically connected with the shell of electronic equipment, so that the interference charge of wiring board be exported.But it is practical implementing this In novel process, at least there are the following problems in the prior art for utility model people discovery: at high temperature, since conductive adhesive layer is swollen It is swollen, so that the conduction that the conducting particles to contact with each other originally in conductive adhesive layer pulls open or script is in contact with electromagnetic shielding film Particle pulls open, and leads to the Joint failure of free ground film and electromagnetic shielding film, to will effectively can not build up in electromagnetic shielding Interference charge export on film, and then interference source is formed, influence the signal transmission of wiring board.

Utility model content

The purpose of the utility model is to provide a kind of free ground film and wiring boards, can be realized free ground film and electromagnetism Screened film is reliably connected, to guarantee the interference charge export in electromagnetic shielding film, to guarantee the complete of signal transmission Whole property.

In order to solve the above-mentioned technical problem, the utility model provides a kind of free ground film, including the first conductor layer, second Conductor layer and adhesive film, first conductor layer are equipped with the first through hole through its upper and lower surface, set at the first through hole There is resin raised, the resin protrusion solidifies after flowing to the other side from the side of the first through hole by resin to be formed；Described Two conductor layers are set to first conductor layer close to the side of the resin protrusion, and cover the resin protrusion, thus in institute The outer surface position corresponding with the resin protrusion for stating the second conductor layer forms lug boss；The adhesive film is set to described second Side of the conductor layer far from first conductor layer；

When the free ground film is used for the ground connection of printed wiring board, electromagnetic shielding is equipped in the printed wiring board Film, the electromagnetic shielding film include the shielded layer and insulating layer being stacked, the free ground film by the adhesive film with The electromagnetic shielding film mutually presses, and the lug boss pierces through the adhesive film and the insulating layer and is electrically connected with the shielded layer It connects.

As an improvement of the above scheme, the resin protrusion is flow to from the side of the first through hole at normal temperature by resin Behind the other side, solidification is formed at curing temperatures；Or,

After the resin protrusion flow to the other side from the side of the first through hole under fusion temperature by resin, through moment It is cooled into.

As an improvement of the above scheme, the surface of the lug boss is equipped with the conductive particles of convex.

As an improvement of the above scheme, the height of the conductive particles is 20 μm -100 μm.

As an improvement of the above scheme, the adhesive film includes the adhesion layer containing conducting particles；Or, the adhesive film packet Include the adhesion layer without conducting particles.

As an improvement of the above scheme, first conductor layer and the second conductor layer respectively include metal conductor layer, carbon is received One of mitron conductor layer, ferrite conductor layer and graphene conductor layer are a variety of.

As an improvement of the above scheme, the number of the first through hole in first conductor layer every square centimeter is 5- 10⁶It is a；And/or the cross-sectional area of the first through hole is 0.01 μm²-1mm²。

As an improvement of the above scheme, the free ground film further includes antioxidation coating, and the antioxidation coating is set to described In one side of first conductor layer far from second conductor layer.

As an improvement of the above scheme, the free ground film further includes peelable protective film layer, the peelable protection Film layer is set in one side of the adhesive film far from second conductor layer.

Compared with prior art, the utility model embodiment discloses a kind of free ground film, by leading described first The resin protrusion is set at the first through hole of body layer, and second conductor layer is set to first conductor layer close to described The side of resin protrusion forms protrusion in the outer surface of second conductor layer position corresponding with the resin protrusion to realize Portion, while the adhesive film is set far from the side of first conductor layer in second conductor layer, so that in the freedom Connect ground film by its adhesive film mutually pressed with electromagnetic shielding film when, the lug boss can successively pierce through the adhesive film and institute The insulating layer of electromagnetic shielding film is stated, and is connect with the shielded layer of the electromagnetic shielding film, to will effectively accumulate in the electricity Interference charge export in magnetic shield film, and then ensure that the ground connection of electromagnetic shielding film, efficiently avoid at high temperature, due to Free ground film is mutually pressed with electromagnetic shielding film by conductive adhesive layer, lead to free ground film and electromagnetic shielding film Joint failure and The problem of interference charge can not being exported rapidly, therefore efficiently avoid interference charge buildup and influence printed wiring board just Often work.

In order to solve identical technical problem, the utility model also provides a kind of wiring board, including printed wiring board, electromagnetism Screened film and above-mentioned free ground film, the electromagnetic shielding film are set in the printed wiring board, the electromagnetic shielding film Including the shielded layer and insulating layer being stacked, the free ground film is mutually pressed by the adhesive film with the electromagnetic shielding film It closes, the lug boss pierces through the adhesive film and the insulating layer and is electrically connected with the shielded layer.

Compared with prior art, the utility model embodiment discloses a kind of wiring board, and the wiring board includes track Free ground film described in road plate, electromagnetic shielding film and above-mentioned any one passes through its adhesive film in the ground film that freely connects When mutually pressing with electromagnetic shielding film, the lug boss can successively pierce through the insulation of the adhesive film and the electromagnetic shielding film Layer, and connect with the shielded layer of the electromagnetic shielding film, thus effectively by the interference accumulated in the electromagnetic shielding film electricity Lotus export, and then ensure that the ground connection of electromagnetic shielding film, it efficiently avoids at high temperature, since free ground film passes through conduction Glue-line is mutually pressed with electromagnetic shielding film, and free ground film is caused charge can not will to be interfered rapid with electromagnetic shielding film Joint failure The problem of export, therefore efficiently avoid the accumulation of interference charge and influence the normal work of printed wiring board.

Detailed description of the invention

Fig. 1 is the structural schematic diagram of the free ground film in the utility model embodiment one；

Fig. 2 is the free ground film cross-sectional view in the utility model embodiment one；

Fig. 3 is the structural schematic diagram of the free ground film in the utility model embodiment two；

Fig. 4 is the structural schematic diagram of the wiring board in the utility model embodiment three；

Fig. 5 is the flow diagram of the preparation method of the free ground film in the utility model embodiment four.

Wherein, the 1, first conductor layer；11, first through hole；12, resin protrusion；13, first surface；14, second surface；2, Second conductor layer；21, lug boss；22, conductive particles；3, adhesive film；4, peelable protective film layer；5, antioxidation coating；6, electromagnetism Screened film；61, insulating layer；62, shielded layer；7, printed wiring board.

Specific embodiment

The following will be combined with the drawings in the embodiments of the present invention, carries out the technical scheme in the embodiment of the utility model Clearly and completely describe, it is clear that the described embodiments are only a part of the embodiments of the utility model, rather than whole Embodiment.Based on the embodiments of the present invention, those of ordinary skill in the art are without creative efforts Every other embodiment obtained, fall within the protection scope of the utility model.

Embodiment one

Referring to figs. 1 and 2, including the first conductor layer 1, the second conductor layer 2 and adhesive film 3, first conductor layer 1 It is equipped with the first through hole 11 through its upper and lower surface, resin protrusion 12, the resin protrusion are equipped at the first through hole 11 12 are flow to behind the other side to solidify and are formed by resin from the side of the first through hole 11；Second conductor layer 2 is set to described the One conductor layer 1 covers the resin protrusion 12 close to the side of the resin protrusion 12, thus in second conductor layer 2 Outer surface position corresponding with resin protrusion 12 form lug boss 21；The adhesive film 3 is set to second conductor layer 2 Side far from first conductor layer 1；

As shown in figure 4, being set in the printed wiring board 7 when the free ground film is used for the ground connection of printed wiring board There is electromagnetic shielding film 6, the electromagnetic shielding film 6 includes the shielded layer 62 and insulating layer 61 being stacked, the free ground film It is pressed by the adhesive film 3 and 6 phase of electromagnetic shielding film, the lug boss 21 pierces through the adhesive film 3 and the insulation Layer 61 is simultaneously electrically connected with the shielded layer 62.

In the utility model embodiment, by the way that the resin is arranged at the first through hole 11 of first conductor layer 1 Protrusion 12, and second conductor layer 2 is set to first conductor layer 1 close to the side of the resin protrusion 12, to realize Lug boss 21 is formed in the outer surface of second conductor layer 2 position corresponding with resin protrusion 12, while described the The adhesive film 3 is arranged far from the side of first conductor layer 1 in two conductor layers 2, so that passing through in the ground film that freely connects When its adhesive film 3 is pressed with 6 phase of electromagnetic shielding film, the lug boss 21 can successively pierce through the adhesive film 3 and the electromagnetism The insulating layer 61 of screened film 6, and connect with the shielded layer 62 of the electromagnetic shielding film 6, to will effectively accumulate in the electricity Interference charge export in magnetic shield film 6, and then ensure that the ground connection of electromagnetic shielding film 6, efficiently avoid at high temperature, by It is mutually pressed by conductive adhesive layer with electromagnetic shielding film in free ground film, leads to free ground film and electromagnetic shielding film Joint failure And the problem of interference charge can not being exported rapidly, therefore efficiently avoid interference charge buildup and influence printed wiring board It works normally, ensure that the integrality of signal transmission.

In the utility model embodiment, in a wherein preferred embodiment, the process of the resin protrusion 12 is formed, specifically After showing themselves in that resin protrusion 12 flow to the other side from the side of the first through hole 11 under fusion temperature by resin, It is formed through instantaneous cooling.And in another preferred embodiment, the resin is solidification glue, the forming process of the resin protrusion 12 Specific manifestation are as follows: at normal temperature, after liquefied resin flow to the other side by the side of the first through hole 11, at curing temperatures Solidification is formed.Wherein, the resin for forming the resin protrusion 12 can be set on the first through hole 11 far from described One end of two conductor layers 2 is also possible to be set in one side of first conductor layer 1 far from second conductor layer 2；In addition, The resin can be thermoplastic resin, be also possible to thermosetting resin.

In the utility model embodiment, it should be noted that the structure of the resin protrusion 12 shown in the drawings is only It is exemplary.Since the resin protrusion 12 is to solidify shape after flowing to the other side from the side of the first through hole 11 by resin At therefore, in a kind of wherein situation, resin is almost flowed out from the first through hole 11, in the first through hole 11 Without remnants, therefore the resin protrusion 12 formed can be as shown in the picture, and the resin protrusion 12 is formed in described first The boundary of through-hole 11 and second conductor layer 2；In another scenario, remnants have resin in the first through hole 11, institute The one end for the resin protrusion 12 stating first through hole 11 or even being filled up by resin, therefore formed is located at the first through hole 11 Interior, the other end of the resin protrusion 12 stretches out the first through hole 11；In another situation, in first conductor layer 1 Side remained on surface far from second conductor layer 2 has resin, and therefore, the resin protrusion 12 of formation can be through institute State first through hole 11.In addition, the resin protrusion 12 in the utility model is by illustrating and above-mentioned shape is limited, as long as It is the resin protrusion with penetration ability, both is within the protection scope of the present invention.

In the utility model embodiment, ensures that and form the resin protrusion at the first through hole 11 12, while guaranteeing that first conductor layer 1 is not easily broken, it is preferable that the cross section face of first through hole 11 described in the present embodiment Product is 0.01 μm²-1mm²。

In addition, in order to guarantee to be capable of forming enough resin protrusions 12 in first conductor layer 1, to ensure The lug boss 21 formed in second conductor layer 2 can smoothly pierce through the insulation of the adhesive film 3 and the electromagnetic shielding film 6 Layer 61 is simultaneously connect with the shielded layer 62, while guaranteeing that first conductor layer 1 is not easily broken, every square centimeter in the present embodiment The number of the first through hole 11 in first conductor layer 1 is 5-10¹⁰It is a.Correspondingly, it every square centimeter described first leads The number of the resin protrusion 12 in body tunic 1 is 5-10¹⁰It is a；It should be noted that since second conductor layer 2 covers The resin protrusion 12, to be formed in the outer surface of second conductor layer 2 with the raised 12 corresponding positions of the resin convex Portion 21 is played, therefore, the number of the lug boss 21 is corresponding with the number of the resin protrusion 12, so that ensure that can be smooth Pierce through the insulating layer 61 of the adhesive film 3 and the electromagnetic shielding film 6 in ground.

In the utility model embodiment, the first through hole 11 can regularly or irregularly be distributed in the screen first It covers on layer 1；Wherein, the first through hole 11, which is regularly distributed in first conductor layer 1, refers to each first through hole 11 Shape is identical, and is evenly distributed in first conductor layer 1；The first through hole 11 is irregularly distributed in described first Refer to the different of each first through hole 11 in conductor layer 1, and is disorderly distributed in first conductor layer 1.Preferably, The shape of each first through hole 11 is identical, and each first through hole 11 is evenly distributed in first conductor layer 1, such as Fig. 2 institute Show.In addition, the first through hole 11 can be circular through hole, it can also be that the through-hole of other arbitrary shapes, the utility model are attached Figure is only that circular through hole is illustrated, but the first through hole 11 of other any shapes all exists with the first through hole 11 Within the protection scope of the utility model.

In the utility model embodiment, it should be noted that the shape of the lug boss 21 can be convex with the resin Rise 12 shape it is identical, can also be different from the shape of the resin protrusion 12, the shape of the lug boss 21 shown in the drawings It is only exemplary.

In the utility model embodiment, the thickness of first conductor layer 1 is preferably 2 μm -45 μm；Second conductor The thickness of layer 2 is preferably 2 μm -45 μm, so that it is guaranteed that first conductor layer 1 and second conductor layer 2 are not easily broken and have There is good flexibility.In order to guarantee that first conductor layer 1 and second conductor layer 2 have good electric conductivity, described the One conductor layer 1 includes one of metal conductor layer, carbon nanotube conductor layer, ferrite conductor layer and graphene conductor layer or more Kind；Second conductor layer 2 includes in metal conductor layer, carbon nanotube conductor layer, ferrite conductor layer and graphene conductor layer It is one or more.Wherein, the metal conductor layer includes monometallic conductor layer and/or alloy conductor layer；Wherein, the Dan Jin Belong to conductor layer be made of any one material in aluminium, titanium, zinc, iron, nickel, chromium, cobalt, copper, silver and gold, the alloy conductor layer by Two or more any material in aluminium, titanium, zinc, iron, nickel, chromium, cobalt, copper, silver and gold is made.

In the utility model embodiment, first conductor layer 1 includes the first surface 13 and the second table being oppositely arranged Face 14, the first surface 13 are in contact with second conductor layer 2；The second surface 14 connects with the protective film layer 4 Touching.It should be noted that the first surface 13 and second surface 14 can be the surface of any shape, for example, can be for such as Flat surface shown in FIG. 1, or contoured non-smooth surface or other rough surfaces；In addition, the first surface 13 and second surface 14 can be rule surface, be also possible to irregular surface.The utility model attached drawing is only with described One surface 13 and second surface 14 are that flat surface is illustrated, the first surface 13 and the second table of other any shapes Face 14 is within the protection scope of the utility model.In addition, what second conductor layer 2 was in contact with the first surface 13 It is also possible to the surface of any shape on one side, for example, can be flat surface as shown in Figure 1, or contoured non- Flat surface or other rough surfaces, do not do more repeat herein.

In the utility model embodiment, it should be noted that first conductor layer 1 of the present embodiment attached drawing and described Second conductor layer 2 all can be single layer structure, or multilayered structure.In addition, according to the needs of actual production and application, this First conductor layer 1 and the second conductor layer 2 of embodiment attached drawing may be configured as latticed, foaming shape etc..

In the utility model embodiment, one of structure of the adhesive film 3, specific manifestation are as follows: the adhesive film 3 Including the adhesion layer containing conducting particles.By making the adhesive film 3 include the adhesion layer containing conducting particles, so that the glue Film layer 3 has the function of bonding, so that the free ground film and the electromagnetic shielding film 6 closely bind, while the glue film Layer 3 also has the function of conduction, matches with second conductor layer 2 and first conductor layer 1, electronics will be interfered rapid Export.Wherein, the conducting particles can be the conducting particles being separated from each other, or bulky grain conductive particle made of reunion Son；When the conducting particles is the conducting particles being separated from each other, the area of electrical contact can further improve, raising electrically connects The uniformity of touching；And bulky grain conducting particles made of being to reunite when the conducting particles, puncture intensity can be increased.

In the utility model embodiment, another structure of the adhesive film 3, specific manifestation are as follows: the adhesive film 3 wraps Include the adhesion layer without conducting particles.By making the adhesive film 3 include the adhesion layer without conducting particles, so that the glue film Layer 3 has the function of bonding, so that the free ground film and the electromagnetic shielding film 6 closely bind, simultaneously because the glue Film layer 3 includes improving the bending of wiring board to reduce the insertion loss of wiring board in use process without conducting particles.

In the utility model embodiment, the adhesive film 3 with a thickness of 0.1 μm -80 μm.Material used in the adhesive film 3 Material is selected from following several: modified epoxy class, acrylic compounds, modified rubber class, modified thermoplastic polyimide.In addition, The outer surface of the adhesive film 3 can be the flat surface without fluctuating, be also possible to the non-smooth surface gently to rise and fall.

As shown in Figure 1, free ground film described in the present embodiment further includes peelable guarantor in order to protect the adhesive film 3 Cuticular layer 4, the peelable protective film layer 4 are set in one side of the adhesive film 3 far from second conductor layer 2.It is described can Removing protective film layer 4 plays a protective role, and is using preceding generation damaged to avoid the adhesive film 3, so that it is guaranteed that the freedom Ground film can be pressed by the adhesive film 3 and 6 phase of electromagnetic shielding film.It should be noted that freely being connect by described When mulch is pressed on the electromagnetic shielding film 6, need to remove on the peelable protective film layer 4, then make the free ground film It is pressed by the adhesive film 3 and 6 phase of electromagnetic shielding film.

In addition, the peelable protective film layer 4 is thin including PPS film layer, PEN film layer, laminated polyester film, polyimides It is film layer that film layer that film layer, epoxy resin ink are formed after solidifying, polyurethane ink are formed after solidifying, acrylic resin modified solid The film layer that the film layer or polyimide resin formed after change is formed after solidifying.

In the utility model embodiment, in order to protect first conductor layer 1, to guarantee charge will be interfered to lead Out, free ground film described in the present embodiment further includes antioxidation coating 5, and it is remote that the antioxidation coating 5 is set to first conductor layer 1 In one side from second conductor layer 2.By being arranged in first conductor layer 1 far from the one side of second conductor layer 2 The antioxidation coating 5 is aoxidized with preventing first conductor layer 1 from contacting with air, to guarantee through the freedom Ground film exports the interference charge in the electromagnetic shielding film 6.

In a kind of wherein preferred embodiment, the material of the antioxidation coating 5 is metal material, ferrite, graphite, carbon nanometer One of pipe, graphene, silver paste；Wherein, the metal material is aluminium, in titanium, zinc, iron, nickel, chromium, cobalt, copper, silver, gold, molybdenum Any one；Or the metal material be aluminium, titanium, zinc, iron, nickel, chromium, cobalt, copper, silver, gold, two kinds or two kinds in molybdenum with The alloy of upper formation；At this point, the antioxidation coating 5 with a thickness of 0.01 μm -5 μm, the thickness of the antioxidation coating 5 is preferably 0.1μm-1μm.In addition, the antioxidation coating 5 can be plated by chemical plating, physical vapour deposition (PVD), chemical vapor deposition, evaporation, be splashed At least two combination process penetrated in one of plating, plating or process above is formed.

In another preferred embodiment, the antioxidation coating 5 is made of the mixture of glue and conducting particles；Wherein, described to lead Charged particle and the volume ratio of the glue are 5%-80%；At this point, the thickness of the antioxidation coating 5 is preferably 0.1 μm -5 μm.Separately Outside, which can be formed by cured technique after coating.

Embodiment two

As shown in figure 3, the free ground film in the present embodiment, difference from the first embodiment is that the protrusion The surface in portion 21 is equipped with the conductive particles 22 of convex.By the way that the conductive particles 22 are arranged on the surface of the lug boss 21, make The lug boss 21 be easier to pierce through the insulating layer 61 of the adhesive film 3 and the electromagnetic shielding film 6, thus guarantee by Interfere charge to export.

Preferably, on the position outwardly protruded on surface of 22 integrated distribution of conductive particles in the lug boss 21, It is easier to pierce through the adhesive film 3 in this way.Certainly, the non-protrusion on the surface of the lug boss 21 can also have conductive particles 22 to divide Cloth.In addition, the conductive particles 22 can also be distributed in second conductor layer 2 close to the adhesive film 3 one side other On position, and it is not only distributed in the surface of the lug boss 21, as shown in Figure 3.Certainly, the conductive particles 22 can also only divide It is distributed in the lug boss 21.

In specific implementation, as shown in figure 3, second conductor layer 2 can be initially formed, then pass through other techniques again The conductive particles 22 are formed far from the side of first conductor layer 1 in second conductor layer 2.Certainly, it described second leads Body layer 2 and conductive particles 22 are also possible to the overall structure formed by one-shot forming technique.

In the utility model embodiment, the conductive particles 22 can exist certain with the outer surface of the adhesive film 3 Distance can also be in contact with the outer surface of the adhesive film 3 or extend the outer surface of the adhesive film 3.

In the utility model embodiment, the highly preferred of the conductive particles 22 is 20 μm -100 μm, the adhesive film 3 Thickness be preferably 0.1 μm -80 μm, the thickness of the insulating layer 61 is preferably 1 μm -20 μm.By the way that the conductive particles are arranged 22 highly preferred is 20 μm -100 μm, and the thickness of the adhesive film 3 is preferably 0.1 μm -80 μm, to ensure the conductive particles 22 can pierce through the insulating layer 61 of the adhesive film 3 and the electromagnetic shielding film 6, ensure that the free ground film can The interference charge gathered on the electromagnetic shielding film 6 is exported.

In the utility model embodiment, the conductive particles 22 include metallic particles, carbon nanotube particulate and ferrite One of particle is a variety of.In addition, the metallic particles includes monometallic particle and/or alloying pellet；Wherein, the Dan Jin Metal particles are made of any one material in aluminium, titanium, zinc, iron, nickel, chromium, cobalt, copper, silver and gold, the alloying pellet by aluminium, Two or more any material in titanium, zinc, iron, nickel, chromium, cobalt, copper, silver and gold is made.Furthermore, it is necessary to explanation It is that the conductive particles 22 can be identical as the material of second conductor layer 2, it can not also be identical.

In the utility model embodiment, it should be noted that the shape of the conductive particles 22 as shown in Figure 3 is only It is exemplary, due to the difference on process means and parameter, the conductive particles 22 can also be cluster-shaped, extension ice-like, clock The other shapes such as mammary calculus shape, dendroid.In addition, the conductive particles 22 in the utility model are not illustrated and above-mentioned shape Limitation, as long as have pierce through and conducting function conductive particles, both be within the protection scope of the present invention.

In addition, the other structures and working principle of the free ground film of the embodiment of the present invention are the same as example 1, herein It does not do and more repeats.

Embodiment three

As shown in figure 4, the utility model embodiment also provides a kind of wiring board, including printed wiring board 7, electromagnetic shielding film 6 and free ground film as described in embodiment 1 or 2, the electromagnetic shielding film 6 is set in the printed wiring board 7, the electricity Magnetic shield film 6 includes the shielded layer 62 and insulating layer 61 that are stacked, the free ground film pass through the adhesive film 3 with it is described The pressing of 6 phase of electromagnetic shielding film, the lug boss 21 pierce through the adhesive film 3 and the insulating layer 61 and with 62 electricity of the shielded layer Connection.

In the present embodiment, the implementation about free ground film can refer to the description of above-described embodiment, herein no longer It repeats.

Preferably, the printed wiring board 7 is flexible single-side, flexibility double face, flexible multi-layer plate, one in rigid-flex combined board Kind.

It, can be by making the free ground film when the wiring board is applied to electronic equipment in specific implementation It is electrically connected with the shell of electronic equipment, to be exported the interference charge in the electromagnetic shielding film 6 is built up.

In the utility model embodiment, by above structure, pressed in the free ground film and the electromagnetic shielding film 6 During conjunction, successively the adhesive film 3 and the insulating layer 61 are pierced using the lug boss 21 in second conductor layer 2 It wears, so that outer surface at least part of second conductor layer 2 is connect with the shielded layer 62 of the electromagnetic shielding film 6, Interference charge is exported to realize under the cooperation of first conductor layer 1 and the second conductor layer 2, avoids interference charge Accumulation and form interference source, to influence the normal work of wiring board.

Example IV

As shown in figure 5, this method is suitable for the preparation of free ground film described in embodiment one, including step S1 to S4:

S1, the first conductor layer is formed；Wherein, first conductor layer has the first through hole through its upper and lower surface；

Wherein, first conductor layer is formed in the following manner in step sl:

Antioxidation coating is formed on a carrier film, forms first conductor layer in the side of the antioxidation coating.

Or, forming strippable coating on a carrier film, first conductor layer is formed on the surface of the strippable coating, After first conductor layer forms antioxidation coating far from the side of the strippable coating, the carrier layer is removed.

In the utility model embodiment, the cross-sectional area of the first through hole is 0.01 μm²-1mm²；It is every square centimeter The number of the first through hole in first conductor layer is 5-10⁶It is a.

S2, resin protrusion is formed at the first through hole；Wherein, the resin protrusion stretches out the first through hole；

It is wherein, described that resin protrusion is formed at the first through hole specifically:

Resin is set at the first through hole, and after so that the resin is flow to the other side from the side of the first through hole Solidification, to form resin protrusion at the first through hole.

Specifically, in a kind of wherein preferred embodiment, resin is set at the first through hole, and makes the resin normal It after flowing to the other side from the side of the first through hole under temperature, solidifies at curing temperatures, thus the shape at the first through hole At resin protrusion；And in another preferred embodiment, resin is set at the first through hole, and makes the resin in fusing temperature After flowing to the other side from the side of the first through hole under degree, through instantaneous cooling, to form resin at the first through hole Protrusion.

S3, the second conductor layer is formed in the side that first conductor layer is formed with the resin protrusion, and makes described the Two conductor layers cover the resin protrusion, thus in the outer surface of second conductor layer position corresponding with the resin protrusion Form lug boss；

S4, adhesive film is formed far from the side of first conductor layer in second conductor layer；The free ground film When ground connection for printed wiring board, it is equipped with electromagnetic shielding film on a printed-wiring board, the electromagnetic shielding film includes that stacking is set The shielded layer and insulating layer set, the free ground film is mutually pressed by the adhesive film with the electromagnetic shielding film, described convex It pierces through the adhesive film and the insulating layer and is electrically connected with the shielded layer in the portion of rising.

It is wherein, described to form adhesive film far from the side of first conductor layer in second conductor layer, specifically:

It is coated with adhesive film on release film, adhesive film pressing is then transferred to second conductor layer far from described The side of first conductor layer, to form adhesive film far from the side of first conductor layer in second conductor layer；Or

It directly is coated with adhesive film far from the side of first conductor layer in second conductor layer, thus described second Conductor layer forms adhesive film far from the side of first conductor layer.

Suitable for another preferred embodiment for preparing electromagnetic shielding film described in embodiment two, after step s 3, And it is further comprised the steps of: before step S4

It plated by physics feather plucking, chemical plating, physical vapour deposition (PVD), chemical vapor deposition, evaporation, sputter plating, be electroplated and is mixed It closes one of plating or kinds of processes and forms conductive particles in the outer surface of the lug boss.

To sum up, the utility model embodiment provides a kind of free ground film and wiring board, wherein the free ground film packet The first conductor layer 1, the second conductor layer 2 and adhesive film 3 are included, first conductor layer 1 is equipped with first through its upper and lower surface Through-hole 11, is equipped with resin protrusion 12 at the first through hole 11, and the resin protrusion 12 is by resin from the first through hole 11 Side solidifies formation after flowing to the other side；Second conductor layer 2 is set to first conductor layer 1 close to the resin protrusion 12 Side, and the resin protrusion 12 is covered, so that the outer surface in second conductor layer 2 is corresponding with the resin protrusion 12 Position formed lug boss 21；The adhesive film 3 is set to side of second conductor layer 2 far from first conductor layer 1；Institute When stating ground connection of the free ground film for printed wiring board, electromagnetic shielding film 6, the electromagnetic screen are equipped in printed wiring board 7 Covering film 6 includes the shielded layer 62 and insulating layer 61 being stacked, and the free ground film passes through the adhesive film 3 and the electromagnetism The pressing of 6 phase of screened film, the lug boss 21 pierce through the adhesive film 3 and the insulating layer 61 and are electrically connected with the shielded layer 62 It connects, to effectively export the interference charge accumulated in the electromagnetic shielding film 6, and then ensure that electromagnetic shielding film 6 Ground connection efficiently avoids at high temperature, since free ground film is mutually pressed by conductive adhesive layer with electromagnetic shielding film, causing certainly The problem of interference charge can not being exported rapidly by ground film and electromagnetic shielding film Joint failure, therefore efficiently avoid doing It disturbs charge buildup and influences the normal work of printed wiring board.

The above is only the preferred embodiment of the utility model, it is noted that for the common skill of the art For art personnel, without deviating from the technical principle of the utility model, several improvement and replacement can also be made, these change It also should be regarded as the protection scope of the utility model into replacement.

Claims (10)

1. a kind of free ground film, which is characterized in that including the first conductor layer, the second conductor layer and adhesive film, described first is led Body layer is equipped with the first through hole through its upper and lower surface, is equipped with resin protrusion at the first through hole, the resin protrusion by Resin solidifies after flowing to the other side from the side of the first through hole to be formed；Second conductor layer is set to first conductor layer Close to the side of the resin protrusion, and cover that the resin is raised, thus second conductor layer outer surface with it is described The corresponding position of resin protrusion forms lug boss；The adhesive film is set to second conductor layer far from first conductor layer Side；

When the free ground film is used for the ground connection of printed wiring board, electromagnetic shielding film, institute are equipped in the printed wiring board Stating electromagnetic shielding film includes the shielded layer and insulating layer being stacked, and the free ground film passes through the adhesive film and the electricity Magnetic shield film mutually presses, and the lug boss pierces through the adhesive film and the insulating layer and is electrically connected with the shielded layer.

2. free ground film as described in claim 1, which is characterized in that the resin protrusion is by resin at normal temperature from described After the side of first through hole flow to the other side, solidification is formed at curing temperatures；Or,

After the resin protrusion flow to the other side from the side of the first through hole under fusion temperature by resin, through instantaneous cooling It is formed.

3. free ground film as described in claim 1, which is characterized in that the surface of the lug boss is equipped with the conductor of convex Grain.

4. free ground film as claimed in claim 3, which is characterized in that the height of the conductive particles is 20 μm -100 μm.

5. free ground film as described in claim 1, which is characterized in that the adhesive film includes sticking together containing conducting particles Layer；Or, the adhesive film includes the adhesion layer without conducting particles.

6. free ground film as described in any one in claim 1-5, which is characterized in that first conductor layer and the second conductor Layer respectively includes one of metal conductor layer, carbon nanotube conductor layer, ferrite conductor layer and graphene conductor layer or a variety of.

7. free ground film as described in any one in claim 1-5, which is characterized in that first conductor layer every square centimeter In the first through hole number be 5-10⁶It is a；And/or the cross-sectional area of the first through hole is 0.01 μm²-1mm²。

8. free ground film as described in any one in claim 1-5, which is characterized in that the free ground film further includes oxygen Change layer, the antioxidation coating is set in one side of first conductor layer far from second conductor layer.

9. free ground film as described in any one in claim 1-5, which is characterized in that the free ground film further includes peelable From protective film layer, the peelable protective film layer is set in one side of the adhesive film far from second conductor layer.

10. a kind of wiring board, which is characterized in that including printed wiring board, electromagnetic shielding film and claim 1-9 any one The free ground film, the electromagnetic shielding film are set in the printed wiring board, and the electromagnetic shielding film includes that stacking is set The shielded layer and insulating layer set, the free ground film is mutually pressed by the adhesive film with the electromagnetic shielding film, described convex It pierces through the adhesive film and the insulating layer and is electrically connected with the shielded layer in the portion of rising.