Background technology
In the slotted eye processing of pcb board (printed circuit board (PCB)), particularly when processing the short slotted eye of flute length/groove footpath < 2 times, generally formed by after the boring of multiple circular hole overlap, namely the drill point adopting diameter to equal slotted eye minor axis during boring bores a hole in short slotted eye one end along its length, bore a hole at the other end of correspondence again, then bore along folded on the length direction of short slotted eye.Due to when the other end boring of short slotted eye, one end of short slotted eye is drill-through, drill point cannot borrow power, when drill point clockwise High Rotation Speed (50000 revs/min ~ 60000 revs/min), apex point knife face produces torsion left, and torsion is greater than the resistance of base material to drill point, thus cause not boring substrate regions to the active force being greater than the left side on the right of drill point generation, thus make the short slotted eye distortion after processing, center along slotted eye length direction offsets 5 ° ~ about 15 ° counterclockwise, as slotted eye minor axis < 1.0 ㎜, its phenomenon is more obviously given prominence to, when particularly processing multi-disc plate at the same time, base plate skew is more serious, cause the finished product yield of PCB plate low, increase production cost.
To this, have when making boring formula, in advance to the angle compensation that short slotted eye carries out to the right, but, when folded brill, because base material remainder is less, also less to apex point active force, the default location after angle compensation can be dropped in the lower brill position of apex point, easily occurs broad bean type slotted eye (special-shaped slotted eye).
Application number is 201010509170.4, the applying date is 2010.10.14, denomination of invention is the method that application discloses the quality problem such as a kind of distortion can effectively avoided in short slotted eye process, groove is large, groove is little of the preparation method of the short slotted eye of a kind of PCB plate, namely in the two edges of the length direction of slotted eye figure, a guide hole is bored respectively, and guide hole diameter is less than the half of slotted eye major diameter, the brill then adopting diameter to equal slotted eye minor axis on guide hole basis is chewed and is carried out superposition boring.Equally, during due to folded brill, its slotted eye is drill-through on one side, drill point cannot borrow power, when drill point clockwise High Rotation Speed (50000 revs/min ~ 60000 revs/min), do not bore substrate regions is greater than left side active force to drill point generation the right, still cause the short slotted eye after processing to deform, the center along slotted eye length direction offsets 5 ° ~ about 15 ° counterclockwise.Simultaneously, due to the edge inscribe of its guide hole and short slotted eye, after first circular hole of short slotted eye has bored, when boring under second circular hole, base material can produce the active force under being greater than to drill point at short slotted eye length direction, cause short slotted eye length can about 0.1 ㎜ shorter in former design length, thus guide hole cannot be covered completely, make the salient point (i.e. guide hole position) that not boring completely appears in short slotted eye edge.
Summary of the invention
The object of this invention is to provide a kind of short slotted eye processing method of pcb board preventing offseting at the short slotted eye process middle slot bore deformation of slotted eye minor axis < 1.0 ㎜.
The present invention adopts following technical scheme to realize its goal of the invention, and the short slotted eye processing method of a kind of pcb board, it comprises the following steps:
(1) in the corresponding edge of waiting out short slotted eye length direction, bore two bullports respectively, slotted eye minor axis < 1.0 ㎜ of described short slotted eye and flute length/groove footpath < 2, the aperture of described bullport is (slotted eye minor axis-0.1)/2 ㎜ ~ (slotted eye minor axis-0.25) ㎜, the line of centres of two bullports and the anticlockwise angle α of slotted eye length direction center line are 10 ° ~ 35 °, and the distance at described bullport and short slotted eye edge is 1 ㏕ ~ 3 ㏕;
(2) the drill point adopting diameter to equal slotted eye minor axis bores a hole in short slotted eye one end along its length, then bores a hole at the other end of correspondence, holes respectively with the edge inscribe of short slotted eye length direction;
(3) then along the folded brill of length direction of short slotted eye.
The present invention is when flute length/groove footpath≤1.3, and described α angle is preferably 29 ° ~ 35 °.
The present invention is when 1.3 < flute length/groove footpath≤1.5, and described α angle is preferably 17 ° ~ 28 °.
The present invention is as 1.5 < flute length/groove footpath < 2, and described α angle is preferably 10 ° ~ 16 °.
The aperture of bullport of the present invention is preferably slotted eye minor axis/2 ㎜.
The distance at bullport of the present invention and short slotted eye edge is preferably 2 ㏕.
Folded brill of the present invention is the length direction along short slotted eye, alternately folds toward center bore from two ends.
Owing to adopting technique scheme, the present invention achieves goal of the invention preferably, by arranging bullport the both sides of short slotted eye length direction center line are oblique, effectively prevent the quality problem such as the short slotted eye distortion in path short slotted eye process, improve the finished product yield of PCB plate, reduce enterprise's production cost.
Detailed description of the invention
Below in conjunction with drawings and Examples, the invention will be further described.
As shown in Figure 1, in the processing of short slotted eye, be generally formed by after the boring of multiple circular hole overlap, the drill point namely adopting diameter to equal slotted eye minor axis during boring bores a hole in short slotted eye one end along its length, bore a hole at the other end of correspondence again, then bore along folded on the length direction of short slotted eye.Due to when the other end boring of short slotted eye, one end of short slotted eye is drill-through, drill point cannot borrow power, when drill point clockwise High Rotation Speed (50000 revs/min ~ 60000 revs/min), apex point knife face produces torsion left, and torsion is greater than the resistance of base material to drill point, thus cause not boring substrate regions to the active force being greater than the left side on the right of drill point generation, thus make the short slotted eye distortion after processing, center along slotted eye length direction offsets 5 ° ~ about 15 ° counterclockwise, as slotted eye minor axis < 1.0 ㎜, its phenomenon is more obviously given prominence to, when particularly processing multi-disc plate at the same time, base plate skew is more serious.
As shown in Figure 2, the distortion in man-hour is added for solving short slotted eye, have when making boring formula, in advance to the angle compensation that short slotted eye carries out to the right, but, when folded brill, because base material remainder is less, also less to apex point active force, the default location after angle compensation can be dropped in the lower brill position of apex point, easily occurs broad bean type slotted eye (special-shaped slotted eye).
As shown in Figure 3, the distortion in man-hour is added for solving short slotted eye, application number is 201010509170.4, the applying date is 2010.10.14, denomination of invention be the patent application of the preparation method of the short slotted eye of a kind of PCB plate provide a kind of length direction at slotted eye figure two edges in bore a guide hole respectively, and guide hole diameter is less than the half of slotted eye major diameter, the brill then adopting diameter to equal slotted eye minor axis on guide hole basis is chewed and is carried out superposition boring.Equally, during due to folded brill, its slotted eye is drill-through on one side, drill point cannot borrow power, when drill point clockwise High Rotation Speed (50000 revs/min ~ 60000 revs/min), do not bore substrate regions is greater than left side active force to drill point generation the right, still cause the short slotted eye after processing to deform, the center along slotted eye length direction offsets 5 ° ~ about 15 ° counterclockwise.Simultaneously, due to the edge inscribe of its guide hole and short slotted eye, after first circular hole of short slotted eye has bored, when boring under second circular hole, base material can produce the active force under being greater than to drill point at short slotted eye length direction, cause short slotted eye length can about 0.1 ㎜ shorter in former design length, thus guide hole cannot be covered completely, make the salient point (i.e. guide hole position) that not boring completely appears in short slotted eye edge.
Embodiment 1:
As shown in Figure 4, the short slotted eye processing method of a kind of pcb board, it comprises the following steps:
(1) in the corresponding edge of waiting out short slotted eye length direction, bore two bullports respectively, slotted eye minor axis < 1.0 ㎜ of described short slotted eye and flute length/groove footpath < 2, the aperture of described bullport is (slotted eye minor axis-0.1)/2 ㎜ ~ (slotted eye minor axis-0.25) ㎜, the line of centres of two bullports and the anticlockwise angle α of slotted eye length direction center line are 10 ° ~ 35 °, and the distance at described bullport and short slotted eye edge is 1 ㏕ ~ 3 ㏕;
The aperture of bullport of the present invention is preferably slotted eye minor axis/2 ㎜.
The distance at bullport of the present invention and short slotted eye edge is preferably 2 ㏕.
(2) the drill point adopting diameter to equal slotted eye minor axis bores a hole in short slotted eye one end along its length, then bores a hole at the other end of correspondence, holes respectively with the edge inscribe of short slotted eye length direction;
(3) then along the folded brill of length direction of short slotted eye.
Folded brill of the present invention is the length direction along short slotted eye, alternately folds toward center bore from two ends.
The present invention is when 1.3 < flute length/groove footpath≤1.5, and described α angle is preferably 17 ° ~ 28 °.
The present embodiment slotted eye minor axis is 0.6 ㎜, slotted eye major diameter/slotted eye minor axis is 1.5, the aperture of bullport is preferably 0.3 ㎜, the distance at described bullport and short slotted eye edge is preferably 2 ㏕, as shown in Figure 4, one hole is centrally located at the lower left quarter of short slotted eye length direction, and another hole is centrally located at the upper right quarter of short slotted eye length direction, and the line of centres of two bullports and the anticlockwise angle α of slotted eye length direction center line are 17 °.
Add man-hour, make boring formula according to designing requirement, formula of holing imports drilling machine.Drilling machine carries out bore operation by instruction, first processes bullport, then one end of the short slotted eye of subdrilling, then bores a circular hole at the other end of short slotted eye, then along the length direction of short slotted eye, from two ends toward middle alternately folded brill.
Owing to being provided with certain distance (the present embodiment is 2 ㏕) between bullport and short slotted eye edge, when making to bore under the second hole, namely can not produce at short slotted eye edge and not bore salient point (bullport position), the effect playing the short slotted eye of correcting can be ensured again.
Embodiment 2:
The present invention is when flute length/groove footpath≤1.3, and described α angle is preferably 29 ° ~ 35 °.
The present embodiment slotted eye minor axis is 0.6 ㎜, and slotted eye major diameter/slotted eye minor axis is 1.3, and the aperture of bullport is preferably 0.3 ㎜, and the line of centres of two bullports and the anticlockwise angle α of slotted eye length direction center line are 31 °.
Remaining with embodiment 1.
Embodiment 3:
The present invention is as 1.5 < flute length/groove footpath < 2, and described α angle is preferably 10 ° ~ 16 °.
The present embodiment slotted eye minor axis is 0.6 ㎜, and slotted eye major diameter/slotted eye minor axis is 1.8, and the aperture of bullport is preferably 0.3 ㎜, and the line of centres of two bullports and the anticlockwise angle α of slotted eye length direction center line are 12 °.
Remaining with embodiment 1.