Summary of the invention
In order to overcome the shortcomings of that prior art, the present invention provide a kind of production method of multilayer printed circuit board, energyThe problem of effective solution background technique proposes.
The technical solution adopted by the present invention to solve the technical problems is:
A kind of production method of multilayer printed circuit board, includes the following steps:
Step 100, multilayer positioning, set calibration point on the equivalent position point of multilayer soft substrate plate, and before drillingMultilayer positioning is carried out according to calibration point, is locked after the positioning, production obtains soft substrate plate, and presses on soft substrate plateSeveral via holes are formed according to five-pointed star distribution drilling；
Step 200, etching development and wiring, by the pattern exposure on original image on photosensitive bottom plate, develop,And single side plate surface is etched, setting signal line group；
Multiport connecting pin is respectively set at both ends in step 300, port closed and molding, and with signal line group pairIt should connect, in the at a temperature of bent circuit board of thermoplastic, and fast cooling is formed；
Step 400, the three-dimensional of multilayer drilling are docked, and are connected on multilayer board corresponding to setting on the position of via holePin is connect, and is electrically connected by enameled wire with pin is connect in corresponding via hole, the signal line group of different layers position is also by mistakeHole connection.
As a preferred technical solution of the present invention, in step 100, the specific steps of drilling are as follows:
Step 101 demarcates five-pointed star distribution figure on soft substrate plate, and avoids track road sign on soft substrate plateFixed drilling position, the soft substrate plate for having demarcated drilling position is projected, retaining projection egative film is spare；
Step 102 drills according to the drilling position of calibration, is rinsed after drilling by dehydrated alcohol, and by nothingWater-ethanol drying；
Step 103, filling tackifying resin closes via hole in via hole, and is polished on two surfaces of via hole, makesHole end surface was obtained to flush with soft substrate plate surface；
Step 104 is fixed with hard fold sheath at soft substrate plate both ends, and center toughness item is embedding by wave strip fixationEnter in hard fold sheath, and it is embedding on soft substrate plate and center toughness item several punching presses to be arranged by stamping deviceEnter hole.
As a preferred technical solution of the present invention, in step 200, by the pattern exposure on original image photosensitiveSpecific steps on bottom plate are as follows:
Step 201 cleans to soft substrate plate, and greasy dirt, oxidation film and its sweat stain including soft substrate plate surface are removingIt rinses and dries by dehydrated alcohol after miscellaneous；
Step 202, preparation standard picture and text silk printing screen version, fix standard picture and text silk printing screen version after spraying photoresists 4-5 timesIt is bonded on soft substrate plate, is directly exposed development；
Step 203 carries out artificial glue less than the place of glue to product edge position and spray, until the metal portion of productPosition is baked to spare without exposing phenomenon.
As a preferred technical solution of the present invention, in step 300, the key step of port closed are as follows: firstly, willMultiport connecting pin is bonded on soft substrate plate, and by its T font edge and soft substrate plate to chimeric；Secondly, by multiportConnecting pin corresponds and is electrically connected with signal line group, and multiport is connected end seal by thermoplastic resin insulating layer laterIt closes.
As a preferred technical solution of the present invention, in step 300, the key step of sizing are as follows: to having already passed throughThe soft substrate plate progress low temperature of port closed is warm slowly, and average heating rate is 2-4 DEG C/min, and being heated to temperature is 50-60DEG C, keep this temperature-resistant, and its temperature fluctuation is no more than 5 DEG C of above-mentioned temperature range, at such a temperature to soft substrate plate intoRow slowly bending and rotation, forms it slowly, and the Mean Speed of bending and rotation is 1-2cm/min, is protected after formationFast cooling after above-mentioned position 5-8min is held, the Mean Speed of cooling is 10-12 DEG C/min.
It further include compacting joint face, on the slim bracket of cross hard as a preferred technical solution of the present inventionConnection structure is suppressed, and is fixed on soft substrate plate.
It further include multilayer board, including soft substrate plate as a preferred technical solution of the present invention, it is described softMatter substrate is equipped with thermoplastic resin insulating layer on two surfaces, it is characterised in that: insulate in soft substrate plate and thermoplastic resinThe signal line group being parallel to each other is equipped between layer, the signal line group is fixed by thermoplastic resin；
It further include center toughness item, the center toughness item is fixedly mounted on soft substrate plate central axis, the centerThe length of toughness item is greater than the long axis length of soft substrate plate, and passes through wave strip and soft substrate plate at the both ends of center toughness itemFixed bonding connection, is uniformly coated with hard fold sheath, the soft base in the junction of the soft substrate plate and wave stripSeveral punching press embedded holes are equipped on plate and center toughness item.
As a preferred technical solution of the present invention, thermoplastic resin insulating layer outer surface is bonded by hot melt adhesiveThere is EMI electromagnetic shielding film, and the connecting sewing for being located at two sides EMI electromagnetic shielding film passes through soldering airtight connection.
As a preferred technical solution of the present invention, it is fixedly installed with and signal line group electricity at the both ends of signal line groupProperty connection multiport connecting pin, the multiport connecting pin is in that T font is embedded in soft substrate plate end, and the signal wireSignal wire in group, which is corresponded with several separate ports of multiport connecting pin, to be electrically connected.
As a preferred technical solution of the present invention, the soft substrate plate includes polyimides or polyester film materialBase sheet, and fixed in above-mentioned base sheet and be bonded with copper clad laminate, the copper clad laminate back side and front are set respectivelyThere are stiffening plate and cover film protection film, wherein the stiffening plate is in hollow rectangular box-like, and in copper clad laminate and basic pieceMaterial is equipped with several via holes being distributed at Five-pointed star.
Compared with prior art, the beneficial effects of the present invention are:
The present invention meets the demand of single-layer-flex circuit, and protecting by the soft substrate plate of setting single layer firstWhile protection circuit hardened structure, additionally it is possible to realize the demand on spatial, spatial stability is very good, three-dimensional convenient for being formedThe Multi-layer circuit board structure of formula, since spatiality is good, thermally conductive and heat dissipation performance is greatly improved, and further,By the way that in circuit board preparation process, directly progress fold, rotation and sizing ensure that the disposal molding of flexible circuit board,The thickness and intensity that ensure that bending part edge are not susceptible to be broken, in production technology, phase can be employed many times in bendingSame template realizes the production of mass, simplifies technique, improves production efficiency.
Specific embodiment
Following will be combined with the drawings in the embodiments of the present invention, and technical solution in the embodiment of the present invention carries out clear, completeSite preparation description, it is clear that described embodiments are only a part of the embodiments of the present invention, instead of all the embodiments.It is based onEmbodiment in the present invention, it is obtained by those of ordinary skill in the art without making creative efforts every otherEmbodiment shall fall within the protection scope of the present invention.
As shown in Figures 1 to 5, described soft the present invention provides a kind of flexible printed circuit board, including soft substrate plate 1Substrate is equipped with thermoplastic resin insulating layer 2 on 1 two surfaces, is equipped between soft substrate plate 1 and thermoplastic resin insulating layer 2The signal line group 3 being parallel to each other, the signal line group 3 are fixed by thermoplastic resin.
Among the above, it should be further noted that soft substrate plate 1 is the basis of circuit board in present embodiment, leadIf being a kind of printed circuit board good with height reliability, pliability made of substrate polyimides or polyester film,And thermoplastic resin insulating layer 2 therein is then capable of providing optimal insulating effect, protects internal electricity structure.
Specifically, in the present embodiment, line can also be sprayed as desired in 2 outer surface of thermoplastic resin insulating layerRoad plate marine glue, so that circuit board has hydrophobic moisture-proof, anti-radiation and anti-aging advantage.
As preferred embodiment, 2 outer surface of thermoplastic resin insulating layer has EMI electromagnetism by melt viscosityScreened film 8, and be located at the connecting sewing of two sides EMI electromagnetic shielding film 8 by soldering airtight connection, among the above, although can be byThe function that wiring board marine glue can have waterproof need to be sprayed, but wiring board is very sensitive for extraneous electromagnetic radiation, therefore, it is necessary to the shielding of electromagnetic signal is carried out, and the EMI electromagnetic shielding film 8 in present embodiment neither interferes other setIt is standby, while also not influenced by other equipment, in a lesser range, it can accomplish the independence of electromagnetic signal, that is,Even when same circuit board on, electromagnetic signal will not be there is a situation where interfering with each other, the effect of shielded signalMost preferably.
Wherein, the multiport connecting pin 9 being electrically connected with signal line group 3 is fixedly installed at the both ends of signal line group 3,The multiport connecting pin 9 is embedded in 1 end of soft substrate plate in T font, and the signal wire in the signal line group 3 with it is moreSeveral separate ports of port connecting pin 9, which correspond, to be electrically connected.
Related signal line group 3 is specially that can be fine signal wire among the above, is also possible to directly pass through etchingMode the foil section on circuit board is removed, to make characteristic impedance match in order to high-speed transfer, be exactly in a word so thatThe main structure and signal transmission structure of circuit board distinguish, the scheme of other signal transmission for meeting the technical programIt is also possible.
Further include center toughness item 4, the center toughness item 4 is fixedly mounted on 1 central axis of soft substrate plate, it is described inThe length of heart toughness item 4 be greater than soft substrate plate 1 long axis length, and the both ends of center toughness item 4 pass through wave strip 5 with it is softThe fixed bonding connection of matter substrate 1 is uniformly coated with hard fold sheath 6 in the junction of the soft substrate plate 1 and wave strip 5,Several punching press embedded holes 7 are equipped on the soft substrate plate 1 and center toughness item 4.
An innovative point of the above-mentioned part as the application, which is characterized in that firstly, 4 one side of center toughness item of settingThe mechanical tenacity of whole circuit board can be improved in face, so that whole circuit board has preferable toughness, can satisfy in the applicationIn flexible circuit board demand.Due in the present embodiment, not only require nothing more than be single sided board circuit board, be also required ofDual platen or even be multiple panel structure, therefore, in the demand of toughness, than general flexible printed circuit board flexibility requirementsIt is much bigger.Another aspect, due to the structures such as the transmission that in this application, has also related to signal, therefore, peripheral device structureGeneral flexible printed board will be more than, and increased peripheral device structure relies solely on the structural strength hardly possible in flexible printing plate itselfTo meet it in mechanical strength the needs of, therefore, if without enough support strengths, it will due to the intensity of structure itselfThe shape in demand and moulding not enough is not achieved, can not meet the demand of flexible circuit board substantially.There are also be exactly to matchInstallation center toughness item 4 is closed, matched hard fold sheath 6 is provided in 1 end of soft substrate plate, further improves circuit boardThe mechanical protection ability at edge, avoids the breakage of board edge.
In addition, the soft substrate plate 1 is equipped with several irregular fold belts 101, and it is located at the hard fold at both endsSheath 101 is rotated on soft substrate plate 1 along two opposite directions around the long axis of spindle of soft substrate plate 1 and forms rotation band 102,The back side and positive two sides of the rotation band 102 are equipped with U-shaped film winding side 103, among the above, the effect of fold belt 101It is to improve the length of practical soft substrate plate 1, and rotation band 102 is formed by turning effort and then can be improved its lateral shearPower enables whole circuit board that can meet the needs of flexible circuit board on horizontal and vertical upper and shear direction,When ensure that circuit board has sufficiently ductile and anti-shearing force, so that it may specifically be produced as desired.
In the present embodiment, the soft substrate plate 1 includes the base sheet 104 of polyimides or polyester film material,It is with polyimides or polyester film for the reason of basic material: there is height reliability, excellent pliability, printing electricityRoad plate has the characteristics that Distribution density is high, light-weight, thickness is thin, bending is good.Fixation is bonded in above-mentioned base sheet 104Copper clad laminate 105,105 back side of copper clad laminate and front are respectively equipped with stiffening plate 106 and cover film protection film 107,In, for the stiffening plate 106 in hollow rectangular box-like, its role is to the mechanical strengths of reinforcement bottom plate, and surface actual load is facilitated to makeIndustry, common thickness have 3mil to 9mil, and are equipped with several into Five-pointed star on copper clad laminate 105 and base sheet 104The via hole of distribution, the via hole of setting are the multiple layer combinations for the ease of circuit board, after being provided with via hole, in the group of circuit boardWhen conjunction, directly internal circuit and signal line can be connected by via hole, avoid the electricity for being additionally provided with peripheral hardware in combinationLine structure.
Specifically, in the present embodiment, being respectively and fixedly provided with cross hard on the front and back in the soft substrate plate 1Slim bracket 10, point is embroidered with several ellipses respectively on the upper slim bracket 10 of cross hard in the back side and front12 shapes and sizes of protrusion one of the protrusion 12 of recess 11 and several ellipses, the oval depressions 11 and ellipse are a pair ofIt answers, and is welded with several coarse points 13 on 11 inner surface of oval depressions.
In the above-mentioned slim bracket 10 of cross hard, its main function is to combine the circuit board of multilayer, stillAfter being provided with above structure, the mechanical strength of integrated circuit plate can also be improved by the slim bracket 10 of cross hard,Being located at the external slim bracket 10 of cross hard can protect internal electrical components, and be located at internal ten for connectionOn the one hand the slim bracket 10 of font hard provides the chimeric position of connection, another aspect is then to be to protect internally positioned electricityLearn component.
In addition, in the present invention, as shown in fig. 6, additionally providing a kind of production method of flexible printed circuit board, including such asLower step:
The processing of step 100, soft substrate plate, production obtain soft substrate plate, and according to five-pointed star point on soft substrate plateCloth drills to form several via holes.
In above-mentioned production stage, the soft substrate plate directly using production is referred to, and the basic composition of the soft substrate plate existsThere is detailed elaboration among the above, it may be assumed that the soft substrate plate 1 includes the base sheet of polyimides or polyester film material104, and fixed in above-mentioned base sheet 104 and be bonded with copper clad laminate 105,105 back side of copper clad laminate and front pointNot She You stiffening plate 106 and cover film protect film 107, wherein the stiffening plate 106 is in hollow rectangular box-like, and in copperFoil substrate 105 and base sheet 104 are equipped with several via holes being distributed at Five-pointed star.Using the excellent of above-mentioned soft substrate plate 1Point is that hierarchical structure clearly demarcated with medium first is convenient for subsequent operation, in addition, in the present embodiment, justIn setting via hole, and the purpose that via hole is arranged is further to be convenient for forming multilayered structure.
Before carrying out step 100, further includes multilayer positioning, calibration is set on the equivalent position point of multilayer soft substrate platePoint, and multilayer positioning is carried out according to calibration point before drilling, it is locked after the positioning.
So-called equivalent position point in the present embodiment, refers specifically to, opposite on the circuit board of different layers positionIn the other circuit boards of circuit board, electrical functions are identical, and identical in electrical functions it is also desirable to ensure its positionThe matching set.Understand in other words and is exactly that on adjacent two pieces of circuit boards, the identical position of electrical functions has very much, and in electricityFunction must also match specific position key point while identical, and such point is on a batch of circuit boardIt is relatively unique.
In step 100, the specific steps of drilling are as follows:
Step 101 demarcates five-pointed star distribution figure on soft substrate plate, and avoids track road sign on soft substrate plateFixed drilling position, the soft substrate plate for having demarcated drilling position is projected, and retaining projection egative film is spare, and the autochrome retainedCan repeatedly utilize, again using when will not need to demarcate again, and mass directly can be carried out by projectionProduction can also improve the harmony and uniformity of same batch production while simplifying process；
Step 102 drills according to the drilling position of calibration, is rinsed after drilling by dehydrated alcohol, and by nothingWater-ethanol drying, the part free matter for rinsing its clast and being adsorbed on soft substrate plate reduce the remaining of impurity, reduceInfluence to subsequent production, and the use of dehydrated alcohol can be repeated several times；
Step 103, filling tackifying resin closes via hole in via hole, and is polished on two surfaces of via hole, makesIt obtained hole end surface to flush with soft substrate plate surface, why close via hole, its role is to make circuit board be in sameOn potential surface, has preferable electromagnetic shielding capability in entire plane；
Step 104 is fixed with hard fold sheath at soft substrate plate both ends, and center toughness item is embedding by wave strip fixationEnter in hard fold sheath, and it is embedding on soft substrate plate and center toughness item several punching presses to be arranged by stamping deviceEnter hole, the punching press embedded hole of setting preferably plays punching press fixed function, and soft substrate plate and the fixation of center toughness item are formed oneBody structure.
In above-mentioned steps, the distribution figure of five-pointed star type why is selected, can be prolonged because five-pointed star type radioactivity is goodMalleability is good, and also has traceability while guaranteeing ductility, convenient for carrying out punching positioning on different circuit boards.
Step 200, etching development and wiring, by the pattern exposure on original image on photosensitive bottom plate, develop,And single side plate surface is etched, setting signal line group.
In step 200, the specific steps by the pattern exposure on original image on photosensitive bottom plate are as follows:
Step 201 cleans to soft substrate plate, and greasy dirt, oxidation film and its sweat stain including soft substrate plate surface are removingIt rinses and dries by dehydrated alcohol after miscellaneous；
Step 202, preparation standard picture and text silk printing screen version, fix standard picture and text silk printing screen version after spraying photoresists 4-5 timesIt is bonded on soft substrate plate, is directly exposed development；
Step 203 carries out artificial glue less than the place of glue to product edge position and spray, until the metal portion of productPosition is baked to spare without exposing phenomenon.
In above-mentioned steps, it should be noted that the specific steps of preparation standard picture and text silk printing screen version are as follows: first by picture and textIt is come out by flat image design software fair drawing, and by picture and text duplicate copy to printing plate output device, picture and text output is being mouldedExpect on film.
Multiport connecting pin is respectively set at both ends in step 300, port closed and molding, and with signal line group pairIt should connect, in the at a temperature of bent circuit board of thermoplastic, and fast cooling is formed.
The key step of port closed are as follows: firstly, multiport connecting pin is bonded on soft substrate plate, and by its T wordType edge and soft substrate plate are to chimeric；Secondly, multiport connecting pin is corresponded and is electrically connected with signal line group, Zhi HoutongThermoplastic resin insulating layer is crossed to close multiport connecting pin.
Wherein, the key step of sizing are as follows: it is hot slowly to the soft substrate plate progress low temperature for having already passed through port closed, it is average to addHot rate is 2-4 DEG C/min, and being heated to temperature is 50-60 DEG C, keeps this temperature-resistant, and its temperature fluctuation is no more than upper5 DEG C for stating temperature range, are slowly bent and are rotated to soft substrate plate at such a temperature, form it slowly, bending andThe Mean Speed of rotation is 1-2cm/min, keeps fast cooling after above-mentioned position 5-8min, the average speed of cooling after formationRate is 10-12 DEG C/min.
Further include following step before carrying out step 400: the three-dimensional docking of multilayer drilling, in multilayer boardSetting connection pin on the upper position corresponding to via hole, and be electrically connected by enameled wire with pin is connect in corresponding via hole,The signal line group of different layers position is connected also by via hole.
Step 400, compacting joint face, suppress connection structure on the slim bracket of cross hard, and be fixed inOn soft substrate plate.
Based on above-mentioned, in this application, it is also necessary to further explanation, the binder resin etc. stated in above contentAdhesive is and to be included the fine grain anisotropic conductive adhesion of conductive extract based on tackifying resin and formed.
It is obvious to a person skilled in the art that invention is not limited to the details of the above exemplary embodiments, Er QieIn the case where without departing substantially from spirit or essential attributes of the invention, the present invention can be realized in other specific forms.Therefore, no matterFrom the point of view of which point, the present embodiments are to be considered as illustrative and not restrictive, and the scope of the present invention is by appended powerBenefit requires rather than above description limits, it is intended that all by what is fallen within the meaning and scope of the equivalent elements of the claimsVariation is included within the present invention.Any reference signs in the claims should not be construed as limiting the involved claims.