The structure of the flexible circuit board of ink-jet printing head and manufacture method
Technical field
The present invention relates to a kind of structure and manufacture method that applies to the flexible circuit board of ink-jet printing head, make in card casket assembling manufacture method, can more properly carry out the bending manufacture method, and in follow-up manufacture method or use problems such as being undermined the caused warpage of residual stress in the time of can avoiding side swipe.
Background technology
Ink-jet printing head is by a flexible circuit board and printer, provide it to transmit and the effect that receives control signal, thereby accurately ink-jet is with printed text or pattern.The assembling of this flexible circuit board, from the side of ink-jet printing head device ink-jet chip through at least bending 90 ° of angles and smooth nearly in adjacent side.
Present flexible circuit board, its specification can generally be divided into double-deck with three layers these two kinds, normally with Polyimide (Polyimide) as base material, there are layer of copper or copper alloy in the surface and so as to being processed as predetermined conducting wire.These two kinds of specifications, its difference is the material on conductive copper wire road, manufacture method and adhere to the mode of Polyimide.Two-layer person is to implement sputter, evaporation or other manufacture method on the surface of its base material in advance, so as to adding a set metal level (as nickel, copper, nickel alloy or copper alloy); Then utilize this metal level of exposure imaging manufacture method etching again, make the transmission line that becomes on the flexible circuit board, and implement again and electroplate or electroforming metal material (as copper).And three layers of person of what is called then are to add the last layer adhesion coating on a flexible substrate surface, paste one deck Copper Foil again after gluing, and then utilize at present known development, etching means this layer Copper Foil to be processed the transmission line that becomes on the flexible circuit board.And open circuit in order to prevent that transmission line oxidation or unexpected scratch from causing, understand usually selectivity on completed circuit top layer with hot pressing attaching, screen painting screen material or coating sensing optical activity cladding material or plate metal level.As a complete unit, no matter use the flexible circuit board of which kind of specification, itself all has certain rigid and is difficult for bending.
Therefore, when carrying out the flexible circuit board assembling manufacture method of ink-jet printing head, in order to ensure the smooth property between flexible circuit board and the ink cartridges, allow automation equipment can accurately aim at the applying position, after generally must utilizing tool with flexible circuit board bending in advance setting, just implement follow-up fixing and applying step.But because due to the rigidity of existing flexible circuit board structure, have stress-retained generation in bending place in advance, so can making, angle bending changes voluntarily, therefore when implementing the automation assembling, aligning accuracy is extremely difficult to be grasped, can't guarantee that each sheet flexible circuit board all can be smooth accurately on the ink-jet casket, thereby cause the instability of assembling quality; But if try to increase the right strong folding of power that pre-folds tool,, easily make transmission line on the flexible circuit board impaired or open circuit the unexpected on the contrary flaw that causes product then in the backfin process.In addition, above-mentioned existing manufacture method, the bending part of the flexible circuit board on the ink-jet casket does not apply cover layer and strengthens protection, will be impaired easily when last casket or during side swipe; Simultaneously, existing manufacture method produces residual stress in the backfin process, causes the warpage issues of flexible circuit board easily, is difficult for overcoming.
In the manufacture method of improving ink-jet printing head; what increase flexible circuit board pre-folds the manufacture method effect; overcome the stress-retained problem of sharp-pointed bending place simultaneously and strengthen protection at its bending part; the present invention proposes evolutionary approach at structure and manufacture method, can be suitable for the utilization of ink-jet printing head.
Summary of the invention
Technical problem to be solved by this invention is to propose a kind of manufacture method that can be applicable to the flexible circuit board of producing ink-jet printing head; make original material promptly pre-fold effect; and effective stress-retained degree that when pre-folding flexible circuit board, produces that reduces; promote the protection of the transmission line of its smooth property and angle position, thereby avoid the transmission line of circuit board corner impaired by side swipe.
Manufacture method of the present invention, its step comprises at least: one, the base material of preparation one flexible circuit board, slotted eye is offered in the position of predetermined bending on base material; Two, metal level on cloth on the base material makes the metal level that has one deck conduction property on the base material of finishing fluting; Three, utilize exposure imaging manufacture method etch metal layers, make the transmission line that becomes flexible circuit board; And four, add a cover layer (is material Solder Mask such as resin as epoxy system or acryl) offering the slotted eye place; by last step finish a residual stress few, can promote its accurate contraposition and smooth property, and have the covering layer or the film of screening strengthen the flexible circuit board of protection in the bending place.
In order to implement above-mentioned purpose better, the invention provides a kind of structure of flexible circuit board of ink-jet printing head, smooth in order to bending in the end and the side person of an ink-jet casket, comprise at least:
One substrate is provided with slotted eye in the predetermined bending of this flexible circuit board part;
One metal transmission line strides across this slotted eye; And
One covering layer, covering are positioned at this slotted eye scope and metal transmission line on every side.
The structure of the flexible circuit board of above-mentioned ink-jet printing head, wherein this base material is a Polyimide (Polyimide) thin slice.
For allowing above and other objects of the present invention, feature and advantage become apparent more, some preferred embodiments cited below particularly, and the conjunction with figs. mark describes in detail.
Description of drawings
Fig. 1 is the end view of general ink-jet printing head;
Fig. 2 is the Facad structure schematic diagram according to flexible circuit board of the present invention;
Fig. 3 is the side cross-sectional view according to flexible circuit board of the present invention; And
Fig. 4 is the flow chart according to manufacture method embodiment of the present invention.
Embodiment
In Fig. 1, the flexible circuit board 20 of ink-jet printing head 10 has the bending place 211 of a wide-angle.In assembling process, if utilize known structure, then be difficult for utilizing the mold pressing fixating shape step to make it to be flattened on the ink-jet casket as this flexible circuit board 20, simultaneously, also be difficult for utilizing automation equipment to make it and be scheduled to the applying position and accurately aim at.
According to embodiments of the invention, can finish as Fig. 2 or flexible circuit board 20 shown in Figure 3; Comprising a substrate 21, a metal transmission line 22 and a covering layer 23; Substrate 21 is offered slotted eye 212 in its predetermined bending part, and metal transmission line 22 then strides across slotted eye 212 along the surface of substrate 21, around the scope of slotted eye 212 reaches, adds that a covering layer 23 is to cover metal transmission line 22 then.
One of best implementation method of the present invention:
As described above: comprise a substrate 21, a metal transmission line 22 and a covering layer 23; And still comprise an adhered layer at metal transmission line 22 and 21 of this substrates.Substrate 21 is offered slotted eye 212 in its predetermined bending part, and metal transmission line 22 strides across slotted eye 212 along substrate 21 surfaces, around the scope of slotted eye 212 reaches, utilizes covering layer 23 to cover metal transmission lines 22 then.And wherein this substrate 21 with Polyimide (Polyimide) material for the most common, this metal transmission line 22 with copper foil material for the most common.
The manufacture method of this most preferred embodiment comprises following each step:
One, fluting A1 gets a flexible circuit board 20 base materials, 211 grooved bore 212 in the needs bending place;
Two, paste the adhered layer material, finishing on the base material of previous step, attaching the material that one deck has viscosity;
Three, metal layer A 2 on the cloth is finished on the base material of previous step, attaches the tinsel (for example copper foil) that one deck has conduction property;
Four, scribe transmission line A3, utilize the manufacture method etching metal paillon foil of exposure imaging, make the transmission line 22 of the flexible circuit board 20 that becomes an ink-jet printing head 10, this transmission line 22 can stride across slotted eye 212; And
Five, add cover layer A4, have the cover layer of protective effect in grooved bore 212 parts interpolation one; For example the part is coated with anti-welding lacquer of last layer (Solder Mask) or membranaceous cover layer, becomes the covering layer 23 that can protect transmission line 22 in the bending place.
Two of best implementation method of the present invention:
According to the present invention, the structure of embodiment can comprise again: a substrate 21, a metal transmission line 22 and a covering layer 23; And still comprise an evaporation or jet-plating metallization material layer at metal transmission line 22 and 21 of this substrates.Substrate 21 is offered slotted eye 212 in its predetermined bending part, and metal transmission line 22 strides across slotted eye 212 along substrate 21 surfaces, around the scope of slotted eye 212 reaches, utilizes covering layer 23 to cover metal transmission lines 22 then.And wherein this substrate 21 with Polyimide (Polyimide) material for the most common, this metal transmission line 22 with copper foil material for the most common.
The manufacture method of this most preferred embodiment comprises following each step:
One, fluting A1 gets a flexible circuit board 20 base materials, 211 grooved bore 212 in the needs bending place;
Two, evaporation or jet-plating metallization material are finished on the base material of previous step, with evaporation or sputtering method cloth last layer metal material;
Three, scribe transmission line A3, utilize the manufacture method etching metal paillon foil of exposure imaging, make the transmission line 22 of the flexible circuit board 20 that becomes an ink-jet printing head 10, this transmission line 22 can stride across slotted eye 212;
Four, metal layer A 2 on the cloth is finished on the base material of previous step, electroplates or the electroforming metal material; And
Five, add cover layer A4, have the cover layer of protective effect in grooved bore 212 parts interpolation one; For example the part is coated with anti-welding lacquer of last layer (Solder Mask) or membranaceous cover layer, becomes the covering layer 23 that can protect transmission line 22 in the bending place.
Manufacture method of the present invention; can make the flexible circuit board of spray ink box be difficult for the accumulation residual stress at bending part; thereby precision, smooth property and the yield of enhancement automation assembling; the protection of one deck cladding material is added in its corner, can avoid transmission line impaired because of the slight friction or the collision of extraneous foreign matter.
Though the present invention discloses as above with preferred embodiment, so its purpose is not in order to limiting the present invention, anyly has the knack of the skill person of this invention, without departing from the spirit and scope of the present invention, does some the design and the retouching of the equivalence of being permitted when having the ability; The inventor will advocate that the right of these equivalence designs must be included in the claim of the present invention.