The specific embodiment
Below in conjunction with accompanying drawing embodiment of the invention electroless copper plating solution circulated filter system and method are described in detail.
Should be clear and definite, described embodiment only is a part of embodiment of the present invention, rather than whole embodiment.Based on the embodiment among the present invention, those of ordinary skills belong to the scope of protection of the invention not making all other embodiment that obtained under the creative work prerequisite.
Referring to Fig. 2, Fig. 4 or Fig. 5, comprise according to the electroless copper plating solution circulated filter system of the embodiment of the invention: heavy copper reaction major trough 1, this heavy copper reaction major trough 1 has the overfall 11 that is used to discharge electroless copper plating solution; Filter (comprising coarse filter and/or fine filtrator), this filter has entrance and exit, and this inlet is connected to overfall 11 by discharging solution circulating line 41; Enter solution circulating line 42, this enters solution circulating line 42 and has first end and second end, this first end links to each other with the outlet of described filter, and this second end extends to the backflow position of heavy copper reaction major trough 1, described backflow position refers to sprays the position that enters into heavy copper reaction major trough 1 when electroless copper plating solution after the filtration refluxes, preferably, described backflow position is positioned at the side-walls relative with described overfall; Wherein, the part that enters that enters described second end of being adjacent to of solution circulating line 42 can be along extending with the bottom surface of heavy copper reaction major trough 1 direction parallel or vertical or that tilt, this enters entering in the part of solution circulating line and has one or more openings 6, opening 6 can be located on the liquid level of the electroless copper plating solution in the heavy copper reaction major trough 1 or under, and the bottom that is in the heavy copper reaction of distance major trough 1 predetermined height at least.
The electroless copper plating solution circulated filter system that present embodiment provides; be provided with one or more openings 6 owing to enter entering in the part of solution circulating line 42; and the bottom that opening 6 is located at the heavy copper reaction of distance major trough 1 is predetermined height at least; therefore pass through the cushioning effect of this predetermined altitude; the deposit that the electroless copper plating solution that enters from opening 6 can directly not react major trough 1 bottom to heavy copper produced large impact; can make copper powder like this; copper residue and substrate break flour remain in the state in the bottom deposit of heavy copper reaction major trough 1 effectively; and then keep the cleaning of the middle and upper part electroless copper plating solution of heavy copper reaction major trough 1, it is bad to have avoided carrying out the print circuit board surface deposition shot copper of electroless copper plating or plug-hole etc. effectively.
In the various embodiments of the present invention, described filter can comprise coarse filter and fine filtrator simultaneously, also can only comprise coarse filter or only comprise fine filtrator.When described filter comprises coarse filter and fine filtrator simultaneously, the inlet of described filter can be the inlet of coarse filter, the outlet of described filter can be the outlet of fine filtrator, and described coarse filter can be connected by intermediate solution circulating line 43 with fine filtrator, that is, coarse filter is in the upstream of fine filtrator; But, if desired, coarse filter also can be in the downstream of fine filtrator.When described filter only comprised coarse filter, the inlet of described filter, outlet can be inlet, the outlet of described coarse filter respectively.When described filter only comprised fine filtrator, the inlet of described filter, outlet can be inlet, the outlet of described fine filtrator respectively.Preferably, coarse filter is provided with one or more screen packs; And/or fine filtrator is provided with one or more filter cores and/or fie screen.
Need to prove that wherein in the various embodiments of the present invention, described coarse filter can preferentially be selected the form of the attached groove of circulating filtration for use, described fine filtrator can preferentially be selected the form that is circulated throughout lauter tub for use.In following examples, be that example is described the solution of the present invention with the coarse filter of the attached flute profile formula of circulating filtration and the fine filtrator of the barrel-shaped formula of circulating filtration, but the invention is not restricted to this.
Below in conjunction with accompanying drawing and by specific embodiment electroless copper plating solution circulated filter system of the present invention is described.
Embodiment one
As shown in Figure 2, be a specific embodiment of electroless copper plating solution circulated filter system of the present invention.In the present embodiment, described electroless copper plating solution circulated filter system comprises heavy copper reaction major trough 1, the attached groove 2 of circulating filtration that connects by solution circulating line 4 and is circulated throughout lauter tub 3.Wherein, the overfall 11 of heavy copper reaction major trough 1 links to each other with the inlet of the attached groove 2 of circulating filtration by discharging solution circulating line 41, the outlet of the attached groove 2 of circulating filtration links to each other with the inlet that is circulated throughout lauter tub 3 by intermediate solution circulating line 43, the outlet that is circulated throughout lauter tub 3 is sprayed the position that enters into heavy copper reaction major trough 1 by entering the backflow position that solution circulating line 42 is connected to heavy copper reaction major trough 1 when reflux for the electroless copper plating solution after filtering in described backflow position.
Preferably, can in the attached groove 2 of the circulating filtration of present embodiment, be provided with one or more screen packs 7, be circulated throughout and be provided with one or more filter cores and/or fie screen in the lauter tub 3.Because the attached groove 2 of circulating filtration is located at the overfall 11 of heavy copper reaction major trough 1 and is circulated throughout between the inlet of lauter tub 3, be circulated throughout between the backflow position that lauter tub 3 is located at the outlet of the attached groove 2 of circulating filtration and heavy copper reaction major trough 1, when the electroless copper plating solution that flows out from overfall 11 enters into the attached groove 2 of circulating filtration by discharging solution circulating line 41 like this, at first it is filtered by screen pack 7, reach the purpose of preliminary filtration, be circulated throughout in the lauter tub 3 filter core (generally to alleviate, filter core can use the wound form cotton core, folding type filter element, integrate shaped type filter core etc.) and/or the filtration of fie screen burden, it is blocked that filter core and/or fie screen are difficult for, and prolonged the service life of filter core and/or fie screen.
Wherein, screen pack 7 can adopt double-deck 36t grenadine, and this screen pack 7 can be unpicked and washed, and long-term use need not change, and is economical and practical.Installing, screen pack 7 can be directly installed on the inlet of the attached groove 2 of circulating filtration, and one section preset distance of outlet of distance discharge solution circulating line 41, and this preset distance can be between 1 cun to 5 cun, for example preferably can be 3 cun.After screen pack 7 filtrations, electroless copper plating solution is discharged from the outlet of the attached groove 2 of circulating filtration again, and enter into by intermediate solution circulating line 43 and to be circulated throughout lauter tub 3, the filter core and/or the fie screen that are circulated throughout in the lauter tub 3 carry out secondary filter to this electroless copper plating solution, with impurity such as the most copper powder of filtering, copper ashes and substrate powder, electroless copper plating solution is cleaned more.Electroless copper plating solution after the filtration is discharged from the outlet that is circulated throughout lauter tub 3, and enters into heavy copper reaction major trough 1 by entering solution circulating line 43.
Though in the present embodiment screen pack 7 is arranged on the porch of the attached groove 2 of circulating filtration, but be not limited thereto, in other embodiments of the invention, also screen pack 7 can be arranged on the exit of the attached groove 2 of circulating filtration or screen pack 7 be arranged on any desired location place between the entrance and exit of the attached groove 2 of circulating filtration.And not only can in the attached groove 2 of circulating filtration, a screen pack 7 be set, and a plurality of screen packs 7 can also be set to form multistage filtering in the attached groove 2 of circulating filtration, strengthen filter effect.
Under state shown in Figure 2, the part that enters that enters solution circulating line 42 is vertically arranged in heavy copper reaction major trough 1, but the present invention is not limited thereto, and this enters part and also can arrange or along inclined direction arrange by along continuous straight runs.Preferably, this enters solution circulating line 42 and is arranged in the position relative with overfall 11 (in this case, the backflow position can be positioned at the side-walls relative with overfall), so that electroless copper plating solution circulates better, perhaps can also other positions that solution circulating line 42 is arranged on overfall 11 both sides will be entered.Enter solution circulating line 42 too near overfall 11 but preferably will avoid making, discharge via overfall 11 immediately via the electroless copper plating solution that enters after the filtration that solution circulating line 42 refluxes avoiding just.Wherein, enter and have one or more openings 6 in the solution circulating line 42.
According to an aspect of the present invention; the bottom that opening 6 is located at the heavy copper reaction of distance major trough 1 is at least on the predetermined altitude H place; the electroless copper plating solution that enters from opening 6 so can not impact the copper powder in the bottom deposit of heavy copper reaction major trough 1; copper residue and substrate break flour; therefore can make copper powder; copper residue and substrate break flour remain in the state in the bottom deposit of heavy copper reaction major trough 1 effectively; and then keep the cleaning of the middle and upper part electroless copper plating solution of heavy copper reaction major trough 1, it is bad to have avoided carrying out the print circuit board surface deposition shot copper of electroless copper plating or plug-hole etc. effectively.
Referring to shown in Figure 2, particularly, the ratio of the height of the predetermined altitude H in the present embodiment and heavy copper reaction major trough 1 can be more than or equal to 20% and smaller or equal to 50%, is preferably more than or equals 30% and smaller or equal to 50%, for example can be 40%.The numerical value of this predetermined altitude H can be set as required in the practical application.Generally speaking, the effect of avoiding having dashed the impurity that is deposited in copper reaction major trough 1 bottom when height H is high more is good more, but the circulating effect of the electroless copper plating solution in the heavy copper reaction major trough 1 is with possible deviation.For this reason, the ratio of the height of described predetermined altitude H and heavy copper reaction major trough 1 can be set between 20% to 50%, can avoid like this via the bottom of the electroless copper plating fluid challenge that enters solution circulating line 42 to heavy copper reaction major trough 1, and then avoid having dashed the impurity that is deposited in copper reaction major trough 1 bottom, and because overfall 11 is opened in the top of heavy copper reaction major trough 1 (because the liquid level of the electroless copper plating solution in the heavy copper reaction major trough 1 will flow out from overfall 11 when arriving overfall 11 places, for guaranteeing to have enough electroless copper plating solution in the heavy copper reaction major trough 1, overfall 11 can be arranged on the top of heavy copper reaction major trough 1), when by opening 6 electroless copper plating solution being drained into the middle and lower part of heavy copper reaction major trough 1 like this, guaranteed that the electroless copper plating solution of the middle and upper part of heavy copper reaction major trough 1 has circulating effect preferably.Wherein, when the ratio with the height of described predetermined altitude H and heavy copper reaction major trough 1 be set in 30% better between 50% the time, the ratio that for example described predetermined altitude H and heavy copper is reacted the height of major trough 1 be set in 40% o'clock best.
Mention the top that overfall 11 is arranged on heavy copper reaction major trough 1 above, guaranteeing when solution-stabilized district (impurity of avoiding being deposited on the bottom is dashed) is formed on the bottom of heavy copper reaction major trough 1, to form circulating effect preferably in the middle and upper part of heavy copper reaction major trough 1.And, heavy copper reaction can fully be carried out in order to guarantee circulating effect preferably further, the part (this enters in the part and is provided with one or more openings 6) that enters that enters solution circulating line 42 can also be immersed in the electroless copper plating solution.And another advantage of this structure is to avoid the solution of ejection from opening 6 to spill the outside that heavy copper reacts major trough 1, pollutes working environment.Certainly, in another embodiment, if desired, also the part that enters that is provided with one or more openings 6 can be remained on the liquid level of electroless copper plating solution, make the reflux solution that drops on the electroless copper plating liquid level of solution can not impact the bottom that heavy copper reacts major trough 1 fully.
As can be seen from Figure 2, discharge electroless copper plating solution by second end that enters solution circulating line 42 and can play ringing, discharge electroless copper plating solution by the opening 6 that enters solution circulating line 42 and then mainly play shunting action.This is because when entering electroless copper plating solution in the solution circulating line 42 and being discharged by opening 6, can reduce or avoid the electroless copper plating solution of from second end, discharging impact, make impurity such as copper powder, copper ashes and substrate powder be deposited on the bottom that copper reacts major trough 1 with remaining valid heavy copper reaction major trough 1 basic sediment.But rectify the bottom surface of heavy copper reaction major trough 1 and may produce greater impact the deposit of heavy copper reaction major trough 1 bottom owing to enter second of solution circulating line 42, therefore preferably also this second end sealing only can be discharged electroless copper plating solution by opening 6.
According to a further aspect in the invention, can regulate opening 6 towards, to avoid the deposit of heavy copper reaction major trough 1 bottom being produced large impact from the solution of opening 6 ejection.Preferably, these a plurality of openings 6 towards can be identical or different mutually, and it is parallel or vertical with the bottom surface of heavy copper reaction major trough 1 or be inclined upwardly or downward-sloping, make and can not impact the diapire that heavy copper reacts major trough 1 along the solution towards ejection of these a plurality of openings 6, can reduce sedimental impact like this, make the impurity on this diapire keep sedimentation state the diapire of heavy copper reaction major trough 1.
As shown in Figure 2, the opening injection direction of left-half opening opening injection direction parallel with the bottom surface of heavy copper reaction major trough 1, the right half part opening is downward-sloping towards the bottom surface of heavy copper reaction major trough 1; Perhaps as shown in Figure 3, on the branch road of level, the opening injection direction of the first half opening along the bottom surface of heavy copper reaction major trough 1 vertically upward, the opening injection direction of the latter half opening towards the bottom surface of heavy copper reaction major trough 1 vertically downward.
For example, in the present embodiment, when the part that enters that enters solution circulating line 42 is arranged on apart from the higher position of diapire or when being arranged on the liquid level top of electroless copper plating solution, the height of the heavy copper reaction of opening 6 distances major trough 1 is bigger, enough cushioning effects can be provided, even therefore opening 6 towards parallel or downward-sloping with respect to the diapire of heavy copper reaction major trough 1 or even downward vertically, can not produce large impact to the deposit of heavy copper reaction major trough 1 bottom yet.Again for example, when enter solution circulating line 42 enter that part is arranged on liquid level below and during apart from the lower position of diapire, the height of the heavy copper reaction of opening 6 distances major trough 1 is less, this moment is in order to provide enough cushioning effects, can make opening 6 towards parallel with respect to the diapire of heavy copper reaction major trough 1 or be inclined upwardly or even upwards vertical, to avoid that the deposit of heavy copper reaction major trough 1 bottom was produced large impact.Perhaps, enter being provided with of partial distance diapire when highly moderate when what enter solution circulating line 42, can make the diapire towards with respect to heavy copper reaction major trough 1 of opening 6 be arranged in parallel or be inclined upwardly or downward-sloping setting, and the angle that tilts can be determined as required, for example can to the scope of 60 degree, tilt, for example can tilt again with the angle of 45 degree at 30 degree.
Above-mentioned to opening 6 towards various settings, purpose is to avoid from the solution of opening 6 ejections the deposit of heavy copper reaction major trough 1 bottom to be caused large impact.This makes and can powerfully not impact copper powder, copper residue and the substrate break flour that the bottom surface of heavy copper reaction major trough 1 deposits from electroless copper plating solution of these openings 6 ejections, can reduce or be avoided the impact to heavy copper reaction major trough 1 basic sediment better.Need to prove, above-mentioned opening 6 towards only being some examples, be not a kind of limitation, according to opening be provided with the position (as liquid level down or liquid level first-class) can be provided with needed opening towards.
Preferably, opening 6 parallel or be inclined upwardly with respect to the bottom surface of heavy copper reaction major trough 1 towards (that is, the injection direction of reflux solution) impacts to the impurity on the bottom surface that is deposited in copper and reacts major trough 1 with the electroless copper plating solution avoiding ejecting.
In one embodiment, opening 6 towards (promptly, the injection direction of reflux solution) be downward-sloping, at this moment, opening 6 towards extended line preferably do not intersect with the bottom surface of heavy copper reaction major trough 1, directly impact the impurity that is deposited on the bottom surface that copper reacts major trough 1 with the electroless copper plating solution of avoiding ejecting.
Preferably, can make the madial wall setting of opening 6 towards heavy copper reaction major trough 1, so that be ejected on the madial wall of heavy copper reaction major trough 1 from the solution of opening 6 ejections, can play cushioning effect better like this, react on the diapire of major trough 1 to avoid being directly injected to heavy copper better from the solution of opening 6 ejections.
Preferably, enter the structure that part can form translation and/or rotation that enters of solution circulating line 42 in the present embodiment.Can adjust this like this and enter part and in heavy copper reaction major trough 1, the position is set, so that the electroless copper plating solution in the heavy copper reaction major trough 1 reaches better circulating effect.
In the present embodiment, the part that enters that enters solution circulating line 42 is slender type, opening 6 is that the electroless copper plating solution that enters like this in the solution circulating line 42 can be along the outflow radially outward that enters solution circulating line 42 (for example shown in Fig. 2 and 4) along longilineal described one or more groups opening vertical or that circumferentially distribute that enters part.
In another embodiment, enter entering partly of solution circulating line 42 and can also be bent to annular (not shown), opening 6 is described one or more groups opening that enters the part distribution along annular.In this case, opening 6 towards preferably with respect to the center of annular and radially outside, that is, solution is from radially outwards ejection of opening 6, and the tiltedly ejection that can abreast or be inclined upwardly or dip down.More preferably, each opening 6 that is provided with along annular is in the center position of heavy copper reaction major trough 1.
According to another aspect of the invention, can be by the flow velocity of valve regulation, to avoid the deposit that heavy copper reacts major trough 1 bottom being produced large impact from the solution of opening 6 ejections from the solution of opening 6 ejections.Preferably, can also in entering solution circulating line 42, valve be installed in the present embodiment, with reflux state, back-flow velocity and the spouting velocity of control electroless copper plating solution.Wherein said reflux state refers to and allows electroless copper plating solution to be back to heavy copper reaction major trough 1 or stop electroless copper plating solution to be back to heavy copper reaction major trough 1, as realizing by opening or closing of switch valve; Described back-flow velocity refers to the flowing velocity of electroless copper plating solution in entering solution circulating line 42; Described spouting velocity refers to the speed of electroless copper plating solution when spraying from opening 6.For example, can in entering solution circulating line 42, switch valve be installed, open this switch valve, electroless copper plating solution is back in the heavy copper reaction major trough 1, close this switch valve, can stop electroless copper plating solution to flow in the heavy copper reaction major trough 1.More preferably, one or more choke valves can be installed in entering solution circulating line 42, this choke valve not only can be controlled the reflux state (opening or closing) of electroless copper plating solution, can also control back-flow velocity and/or spouting velocity by the flow that this choke valve is flow through in control; The valve that is used to control spouting velocity can certainly be installed separately in the described backflow position that is adjacent to opening 6.In addition, according to user demand, the valve of other types can also be installed in entering solution circulating line 42.
According to a preferred embodiment of the invention, can with opening be provided with height, opening towards and opening in the jet velocity triplicity of electroless copper plating solution use, promptly, control any combination among this three, thereby avoid the deposit that heavy copper reacts major trough 1 bottom being produced large impact, more effectively make copper powder, copper residue and substrate break flour etc. remain in the state that reacts the bottom deposit of major trough 1 at heavy copper from the electroless copper plating solution that the opening that enters part 6 backflows that enter solution circulating line 42 are sprayed.
In various embodiments of the present invention, for fear of the electroless copper plating solution that enters from the opening 6 that enters part that enters solution circulating line 42 deposit that heavy copper reacts major trough 1 bottom was produced large impact, make copper powder, copper residue and substrate break flour etc. remain in the state that reacts the bottom deposit of major trough 1 at heavy copper effectively, can use following three kinds of features.First kind of feature can be arranged on opening 6 predetermined height at least that the heavy copper of distance reacts major trough 1 bottom, with the solution that sprays from opening 6 by the solution buffering in the heavy copper reaction major trough 1; Second kind of feature, can make opening 6 towards parallel or vertical with the bottom surface of heavy copper reaction major trough 1 or be inclined upwardly or downward-sloping, to avoid the deposit that heavy copper reacts major trough 1 bottom being produced large impact from the solution of opening 6 ejections; The third feature can be controlled from the jet velocity of the heavy copper solution of refluxing chemical of opening 6 ejections by being installed in the valve that enters in the solution circulating line.
Above-mentioned three kinds of features can be used separately or be used in combination as the case may be.For example, when the jet velocity of the electroless copper plating solution that refluxes is very fast, opening 6 can be located at the higher position, bottom of the heavy copper reaction of distance major trough 1, can also make opening 6 towards parallel or upwards vertical with respect to the bottom surface of heavy copper reaction major trough 1 or be inclined upwardly.Again for example, when opening 6 towards downward vertically the time with respect to the bottom surface of heavy copper reaction major trough 1, can make the jet velocity of electroless copper plating solution of backflow slower, perhaps opening 6 can also be located at the higher position, bottom of the heavy copper reaction of distance major trough 1.The example that above-mentioned three kinds of features are used in combination can reach the Expected Results of the embodiment of the invention above, and the electroless copper plating fluid challenge of promptly avoiding refluxing is deposited in the impurity that copper reacts major trough 1 bottom.
As shown in Figure 3, in other embodiments of the invention, enter solution circulating line 42 and can have one or more branch roads, for example can be provided with first branch road and second branch road of two levels, and one or more openings can be set on each branch road in the both sides that enter solution circulating line 42.Certainly, the described bearing of trend that enters solution circulating line 42, first branch road and second branch road also is not limited to vertical direction or horizontal direction, can also be incline direction as required.
In sum, and learn, use electroless copper plating solution circulated filter system in this enforcement can avoid printed substrate plate face deposition shot copper effectively and to cross hole plug etc. bad, and can reduce use cost by test of many times.Wherein, the filter effect and the use cost of electroless copper plating solution circulated filter system seen as following table 1 in the filter effect of present embodiment electroless copper plating solution circulated filter system and use cost and the prior art.
Table 1
Embodiment two
As shown in Figure 4, be another specific embodiment of electroless copper plating solution circulated filter system of the present invention.In the present embodiment, described electroless copper plating solution circulated filter system comprises heavy copper reaction major trough 1 and the attached groove 2 of circulating filtration that connects by solution circulating line 4, the overfall 11 of wherein heavy copper reaction major trough 1 links to each other with the inlet of the attached groove 2 of circulating filtration by discharging solution circulating line 41, and the outlet of the attached groove 2 of circulating filtration is by entering the backflow position that solution circulating line 42 is connected to heavy copper reaction major trough 1.
In the present embodiment, the porch of the attached groove 2 of circulating filtration has screen pack 7, and the attached groove 2 of circulating filtration is located between the overfall 11 and backflow position of heavy copper reaction major trough 1.Like this, when the electroless copper plating solution that flows out from overfall 11 enters into the attached groove 2 of circulating filtration by discharging solution circulating line 41, can filter it by screen pack 7, with the impurity such as copper powder, copper ashes and substrate powder that carry in the filtering electroless copper plating solution.After screen pack 7 filtrations, electroless copper plating solution is discharged from the outlet of the attached groove 2 of circulating filtration, and enters into heavy copper reaction major trough 1 by entering solution circulating line 42.Because the impurity that deposits in the heavy copper reaction major trough 1 is difficult to be dashed, therefore the attached groove 2 of circulating filtration can only be set and filters in the present embodiment.For attached groove 2 of circulating filtration and screen pack 7 can adopt with aforementioned first embodiment in identical mode, do not repeat them here.Difference is only described below.
Under state shown in Figure 4, entering solution circulating line 42 arranges along horizontal-extending at the inwall place of major trough 1, and enter and have one or more openings 6 that along continuous straight runs distributes in the solution circulating line 42, opening 6 is located on the bottom predetermined altitude H of the heavy copper reaction of distance major trough 1, and opening 6 towards with the bottom surface almost parallel or the inclination of heavy copper reaction major trough 1, and opening 6 is arranged on below the liquid level of heavy copper reaction major trough 1.The electroless copper plating solution that enters from opening 6 so can not produce large impact to the deposit of heavy copper reaction major trough 1 bottom; can make copper powder, copper residue and substrate break flour be deposited on the bottom of copper reaction major trough 1 with remaining valid; and then keep heavy copper to react the cleaning of the middle and upper part electroless copper plating solution of major trough 1, avoided print circuit board surface deposition shot copper or plug-hole etc. bad better.
Embodiment three
As shown in Figure 5, be another specific embodiment of electroless copper plating solution circulated filter system of the present invention.In the present embodiment, described electroless copper plating solution circulated filter system comprises the heavy copper reaction major trough 1 that connects by solution circulating line 4 and is circulated throughout lauter tub 3, the overfall 11 of wherein heavy copper reaction major trough 1 links to each other with the inlet that is circulated throughout lauter tub 3 by discharging solution circulating line 41, and the outlet that is circulated throughout lauter tub 3 links to each other with the backflow position of heavy copper reaction major trough 1 by entering solution circulating line 42.
In the present embodiment, be circulated throughout between the backflow position that lauter tub 3 is located at the outlet of the attached groove 2 of circulating filtration and heavy copper reaction major trough 1.Like this, the electroless copper plating solution that flows out from overfall 11 enters into and is circulated throughout lauter tub 3 by discharging solution circulating line 41, and the cotton core that is circulated throughout in the lauter tub 3 filters this electroless copper plating solution, with impurity such as filtering copper powder, copper ashes and substrate powder.Electroless copper plating solution after the filtration is discharged from the outlet that is circulated throughout lauter tub 3, and enters into heavy copper reaction major trough 1 by entering solution circulating line 43.
Wherein, the arrangement that enters solution circulating line 42 embodiment illustrated in fig. 5 is identical with the arrangement that enters solution circulating line 42 embodiment illustrated in fig. 2.Enter and have opening 6 in the solution circulating line 42; opening 6 is located on the bottom predetermined altitude H of the heavy copper reaction of distance major trough 1; the electroless copper plating solution that enters from opening 6 so can not produce large impact to the deposit of heavy copper reaction major trough 1 bottom; can make copper powder, copper residue and substrate break flour be deposited on the bottom of copper reaction major trough 1 effectively; keep the cleaning of heavy copper reaction major trough 1 middle and upper part electroless copper plating solution, avoided print circuit board surface deposition shot copper or plug-hole etc. bad better.In the present embodiment since in the heavy copper reaction major trough 1 impurity of deposition be difficult to be dashed, so can only be provided with and be circulated throughout lauter tub 3 and filter.For be circulated throughout lauter tub 3 adopt with aforementioned first embodiment in identical mode, do not repeat them here.
In addition, the embodiment of the invention also provides a kind of electroless copper plating circulating filtration method.As shown in Figure 6, described electroless copper plating solution circulating filtration method comprises:
S601 enters the electroless copper plating solution in the heavy copper reaction major trough in the filter;
S602 filters described electroless copper plating solution by described filter;
S603, the predetermined height at least in the heavy copper reaction of distance major trough bottom refluxes electroless copper plating solution after the filtration and is ejected in the described heavy copper reaction major trough.
Present embodiment electroless copper plating solution circulating filtration method; owing to be in the heavy copper reaction of distance major trough bottom at least during predetermined height; electroless copper plating solution backflow after filtering is ejected in the described heavy copper reaction major trough; therefore the electroless copper plating solution that enters from described opening can be not directly produce large impact to the deposit bottom the described heavy copper reaction major trough; can make copper powder like this; copper residue and substrate break flour are deposited on the bottom of described heavy copper reaction major trough effectively; keep the cleaning of described heavy copper reaction major trough middle and upper part electroless copper plating solution, avoided print circuit board surface deposition shot copper or plug-hole etc. bad better.
Specify described electroless copper plating solution circulating filtration method below in conjunction with accompanying drawing.As shown in Figure 7, this method comprises:
S701 enters the electroless copper plating solution in the heavy copper reaction major trough in the filter.
Particularly, on the sidewall of described heavy copper reaction major trough, offer overfall, can electroless copper plating solution be drained in the described filter by the discharge solution circulating line that is connected on the overfall.
In the various embodiments of the present invention, described filter can comprise coarse filter and fine filtrator simultaneously, also can only comprise coarse filter or only comprise fine filtrator.Preferably, coarse filter is provided with one or more screen packs; And/or fine filtrator is provided with one or more filter cores and/or fie screen.Wherein when described filter not only comprised coarse filter but also comprises fine filtrator, coarse filter was in the upstream of fine filtrator; But, if desired, coarse filter also can be in the downstream of fine filtrator.Need to prove that wherein in the various embodiments of the present invention, described coarse filter can preferentially be selected the form of the attached groove of circulating filtration for use, described fine filtrator can preferentially be selected the form that is circulated throughout lauter tub for use.In following examples, be that example is described the solution of the present invention with the coarse filter of the attached flute profile formula of circulating filtration and the fine filtrator of the barrel-shaped formula of circulating filtration, but the invention is not restricted to this.
S702, described coarse filter tentatively filters electroless copper plating solution, preferably uses screen pack that electroless copper plating solution is tentatively filtered, with impurity such as filtering part copper powder, copper ashes and substrate powder.And the electroless copper plating solution after will tentatively filtering enters in the described fine filtrator by pipeline.
S703, the described fine filtrator electroless copper plating solution after to preliminary filtration carries out secondary filter, with impurity such as the most copper powder of filtering, copper ashes and substrate powder, electroless copper plating solution is cleaned more.
S704, make electroless copper plating solution after the filtration in the heavy copper reaction of distance major trough bottom at least predetermined height reflux and be ejected in the described heavy copper reaction major trough.
Preferably, the electroless copper plating solution after will filtering described in the present embodiment refluxes to be ejected in the described heavy copper reaction major trough and is specifically as follows: the electroless copper plating solution after will filtering is ejected into described heavy copper and reacts in the major trough by refluxing dispersedly towards identical or different a plurality of openings.By described a plurality of openings solution is refluxed dispersedly, can reduce the amount of the electroless copper plating solution of each described opening discharge, and then the electroless copper plating solution that reduces to discharge further makes impurity such as copper powder, copper ashes and substrate powder be deposited on the bottom of described heavy copper reaction major trough effectively to the impulsive force of described heavy copper reaction major trough basic sediment.
Preferably, when the electroless copper plating solution in the present embodiment after will filtering is ejected in the described heavy copper reaction major trough by refluxing dispersedly towards identical or different a plurality of openings, the flow direction of the electroless copper plating solution after the described filtration is parallel or vertical with the bottom surface of described heavy copper reaction major trough or be inclined upwardly or downward-sloping, so also can reduce described heavy copper is reacted the impulsive force of major trough basic sediment.For example, the position that enters described heavy copper reaction major trough when electroless copper plating solution apart from the diapire height of described heavy copper reaction major trough hour, the flow direction that can make electroless copper plating solution is parallel with the bottom surface of described heavy copper reaction major trough or be inclined upwardly, so that entering of electroless copper plating solution produced certain cushioning effect, avoid the deposit on the described heavy copper reaction major trough diapire is caused excessive shock.Wherein, the flow direction of the electroless copper plating solution after can controlled filter by described a plurality of openings.
At this on the one hand, preferably, can be provided with described a plurality of openings towards and make its towards extended line do not intersect with the bottom surface of heavy copper reaction major trough 1, and therefore avoid electroless copper plating solution that the impurity on the bottom surface that is deposited in copper and reacts major trough 1 is impacted.For example, with reference to shown in Figure 2, the opening injection direction of its left-half opening is parallel with the bottom surface of heavy copper reaction major trough 1, the opening of this part opening towards extended line crossing with the bottom surface of heavy copper reaction major trough 1; The opening injection direction of its right half part opening is downward-sloping towards the bottom surface of heavy copper reaction major trough 1, by regulate this part opening height is set or from the spouting velocity of the electroless copper plating solution of this opening ejection, also can reach the opening that makes this part opening towards the effect that do not intersect with the bottom surface of heavy copper reaction major trough 1 of extended line.Perhaps horizontal branches as shown in Figure 3, the opening injection direction of the first half opening along the bottom surface of heavy copper reaction major trough 1 vertically upward, the opening of this part opening towards extended line do not intersect with the bottom surface of heavy copper reaction major trough 1.The opening injection direction of its latter half opening towards the bottom surface of heavy copper reaction major trough 1 vertically downward, similarly, by regulate this part opening height is set or from the spouting velocity of the electroless copper plating solution of this opening ejection, also can reach the opening that makes this part opening towards the effect that do not intersect with the bottom surface of heavy copper reaction major trough 1 of extended line.In the present embodiment by the jet velocity triplicity that electroless copper plating solution in height and the opening is set of opening injection direction, opening is used, make and can not impact the bottom surface that heavy copper reacts major trough 1 along the solution towards ejection of these a plurality of openings 6, can reduce sedimental impact like this, make the impurity on this bottom surface keep sedimentation state the diapire of heavy copper reaction major trough 1.
For example, in the present embodiment, when the part that enters that enters solution circulating line 42 is arranged on apart from the higher position of diapire or when being arranged on the liquid level top of electroless copper plating solution, the height of the heavy copper reaction of opening 6 distances major trough 1 is bigger, enough cushioning effects can be provided, even therefore opening 6 towards parallel or downward-sloping with respect to the diapire of heavy copper reaction major trough 1 or even downward vertically, can not produce large impact to the deposit of heavy copper reaction major trough 1 bottom yet.Again for example, when enter solution circulating line 42 enter that part is arranged on liquid level below and during apart from the lower position of diapire, the height of the heavy copper reaction of opening 6 distances major trough 1 is less, this moment is in order to provide enough cushioning effects, can make opening 6 towards parallel with respect to the diapire of heavy copper reaction major trough 1 or be inclined upwardly or even upwards vertical, to avoid that the deposit of heavy copper reaction major trough 1 bottom was produced large impact.Perhaps, enter being provided with of partial distance diapire when highly moderate when what enter solution circulating line 42, can make the diapire towards with respect to heavy copper reaction major trough 1 of opening 6 be arranged in parallel or be inclined upwardly or downward-sloping setting, and the angle that tilts can be determined as required, for example can to the scope of 60 degree, tilt, for example can tilt again with the angle of 45 degree at 30 degree.
Above-mentioned to opening 6 towards various settings, purpose is to avoid from the solution of opening 6 ejections the deposit of heavy copper reaction major trough 1 bottom to be caused large impact.This makes and can powerfully not impact copper powder, copper residue and the substrate break flour that the bottom surface of heavy copper reaction major trough 1 deposits from electroless copper plating solution of these openings 6 ejections, can reduce or be avoided the impact to heavy copper reaction major trough 1 basic sediment better.Need to prove, above-mentioned opening 6 towards only being some examples, be not a kind of limitation, according to opening be provided with the position (as liquid level down or liquid level first-class) can be provided with the opening that needs towards.
Preferably, electroless copper plating solution in the present embodiment after making filtration refluxes when being ejected in the described heavy copper reaction major trough, can make on the madial wall that is ejected into described heavy copper reaction major trough of the electroless copper plating solution after the described filtration.The concrete madial wall setting that can make opening 6 in realization towards heavy copper reaction major trough 1, so that be ejected on the madial wall of heavy copper reaction major trough 1 from the solution of opening 6 ejections, can play cushioning effect better like this, react on the diapire of major trough 1 to avoid being directly injected to heavy copper better from the solution of opening 6 ejections.
Perhaps, electroless copper plating solution after the filtration is refluxed be ejected in the described heavy copper reaction major trough specifically and can also be ejected into described heavy copper and react in the major trough for: the electroless copper plating solution after will filtering refluxes with predetermined back-flow velocity and/or jet velocity.This can be by installing valve on the pipeline that enters electroless copper plating solution, and the flow velocity of the solution that sprays from described opening by valve regulation is realized.
In various embodiments of the present invention, for fear of the electroless copper plating solution that enters the deposit bottom the described heavy copper reaction major trough was produced large impact, make copper powder, copper residue and substrate break flour etc. be in the state of the bottom deposit of described heavy copper reaction major trough effectively, can use following three kinds of features.First kind of feature can be at the heavy copper reaction solution after predetermined height enters filtration at least of the described heavy copper reaction of distance major trough bottom; Second kind of feature, the flow direction when electroless copper plating solution is entered is parallel or vertical with the bottom surface of described heavy copper reaction major trough or be inclined upwardly or downward-sloping; The third feature can be controlled the back-flow velocity and/or the jet velocity of the electroless copper plating solution that enters.
Above-mentioned three kinds of features can be used separately or be used in combination as the case may be.For example, when the jet velocity of the electroless copper plating solution that refluxes is very fast, described opening can be located at the higher position, bottom of the described heavy copper reaction of distance major trough, can also make the parallel or upwards vertical or be inclined upwardly with respect to the bottom surface of heavy copper reaction major trough 1 of described opening towards (and electroless copper plating solution flow direction when entering).Again for example, when described opening towards downward vertically the time with respect to the bottom surface of described heavy copper reaction major trough, can make the jet velocity of electroless copper plating solution of backflow slower, perhaps described opening can also be located at the described heavy copper reaction of distance higher position, major trough 1 bottom.The example that above-mentioned three kinds of features are used in combination can reach the Expected Results of the embodiment of the invention above, and the electroless copper plating fluid challenge of promptly avoiding refluxing is deposited in the impurity that copper reacts major trough 1 bottom.
The above; only be the specific embodiment of the present invention, but protection scope of the present invention is not limited thereto, anyly is familiar with those skilled in the art in the technical scope that the present invention discloses; can expect easily changing or replacing, all should be encompassed within protection scope of the present invention.Therefore, protection scope of the present invention should be as the criterion by described protection domain with claim.