TWI415701B - Printed board for printing substrates - Google Patents

Abstract

The invention provides a rotary cutting tool. Compared with a conventional rotary cutting tool with a constant helical angle cuttings chute, the rotary cutting tool keeps good cutting machining for a long distance and has very excellent practicability. A plurality of spiral cuttings chutes (3) towards the proximal end side from the end of the tool are formed on the cirumference of the tool main body (1) and after the front tool surface of the cuttings chute (3) is crossed with the cirumferential surface of the tool main body (1) or the front tool surface of the cuttings chute (3) is crossed with the cirumferential back tool surface formed at the cirumference of the tool main body (1), a cirumferential cutting edge is formed at the crosses edge part and the helical angle (alpha) of the cirumferential cutting edge gradually increases from the end of the tool towards the proximal end side.

Description

Luda knife for printing substrate processing

The present invention relates to rotary cutting tools, particularly road blades for printing substrate processing.

Generally, a printed circuit board is produced by cutting a plurality of small-sized printed boards of the same specification from a mother board. For example, after a plurality of mother boards are superimposed and subjected to hole processing, various mother boards are subjected to etching and plating treatment to form a pattern, and the mother sheets subjected to the above processes are overlapped in plurality, and individually cut out using a rotary cutting tool. Manufactured from a small-sized printed substrate of the same specification. This cutting process is generally referred to as profile processing. Further, in the hole processing and the outer shape processing, in order to allow a predetermined substrate to pass through so as to be able to be processed, it is common to superimpose the substrate on the disposal board, and to stack a plurality of substrates in order to improve the production efficiency.

As a rotary cutting tool for performing such external shape processing, for example, a router bit for processing a printed circuit board disclosed in Patent Document 1 is known.

For such a road milling cutter, the cutting dust discharge groove is generally spirally formed at a predetermined twist angle on the outer circumference of the tool body, and the rake face of the chip discharge groove and the outer peripheral surface of the tool body are generally provided. (or a peripheral ridge portion formed on the outer peripheral retracting surface of the outer periphery of the tool body) to form a peripheral cutting blade.

However, as illustrated in Fig. 1, the torsion angle α of the outer peripheral cutter 2 of the tool body 1 is generally set to a fixed angle from the front end to the base end. also In order to exert the effect of cutting off the chips, a cutting chip cutting groove (hereinafter referred to as a chip breaker) is generally provided, which is recessed in the outer peripheral cutting blade 2' for cutting the spiral continuous outer circumference. Cutting knife 2'. Further, the symbol B' in Fig. 1 is a schematic view showing a chip breaker which is disposed on the outer circumference of the tool body only in a predetermined number of spiral rotation directions, and specifically refers to a plurality of peripheral cutters which are cut by the chip breaker. The end point is connected to the imaginary line of the spiral rotation direction of the chip breaker. The angle (cutting angle β') of the imaginary line B' is also a fixed angle from the front end to the base end. Further, Fig. 1 shows that the spiral rotation direction of the chip discharge groove or the outer peripheral cutter 2' is right (right twist), and the spiral rotation direction of the chip breaker is left (left twist).

[Advanced technical literature]

[Patent Literature]

[Patent Document 1] Japanese Patent Laid-Open Publication No. 2004-202591

As described above, in general, when the outer shape of the mother board is processed, a plurality of overlapping processes are performed. Fig. 2(a) shows a schematic diagram and cutting resistance when the outer shape is processed by a router having a peripheral cutter having an extremely right right-knife twist. In this case, the cutting resistance R represents the feeding force component Fy of the feeding direction and the reverse direction of the Luda knife, the back component force Fx acting on the feeding component Fy in the right angle direction, and the axial direction of the road knife. The component force is the resultant force of the vertical component force Fz, and the cutting resistance R is actuated to the left oblique rearward direction of the feeding direction of the road knife. As shown in Fig. 2(b), as a result of the machining of the Luda knife in the profile machining by the cutting resistance R, the machined side surface is formed into a collapsed shape, particularly the amount of collapse of the portion of the tool leading end side which is subjected to the cutting process. (equivalent to the deflection of the front end of the tool) becomes larger.

When the amount of collapse δ is too large, not only the dimensional accuracy required for the printed substrate cannot be satisfied, but also the peripheral cutting blade is formed because the processed side forms a collapsed shape at the end of the outer shape processing. It is a peripheral cutting blade on the front end side of the tool. It is easy to contact the machined side surface, and there is a problem that the outer peripheral cutting blade is damaged and the durability of the tool is deteriorated.

Further, since the plurality of mother boards are stacked and the outer shape is processed, if the cutting of the chips is not smoothly performed, when the machining is performed only for a short distance, there is a problem that the tools are broken due to the accumulation of the chips.

Furthermore, the inventors of the present invention have obtained the finding that the torsion angle of the outer peripheral cutting blade (chip discharge groove) that actually exerts the cutting action is simply such that the tool base end side is larger than the tool front end side because The influence of the torsion angle of the cutting dust discharge groove on the base end side improves the chip discharge performance. On the other hand, since the torsion angles of the outer peripheral cutting blades are different, the cutting impedance is different in the boundary of the torsion angle. This causes the accuracy of the machined surface to deteriorate, the peripheral cutting blade to be damaged, or the damage of the tool itself.

According to the present invention, the inventors of the present invention have studied the twist angle of the chip discharge groove (outer peripheral cutting blade) of the rotary cutting tool, and obtained a method in which the twist angle is gradually increased from the tool tip toward the base end side. In order to achieve further improvement in workability and durability, a rotary cutting tool with excellent practicality is provided, which can maintain good cutting work over a long distance compared to a conventional rotary cutting tool in which the torsion angle is fixed. .

The gist of the present invention will be described with reference to the drawings.

A rotary cutting tool is formed on a periphery of the tool body 1 with a plurality of spiral chip discharge grooves 3 from a tool tip toward a base end side, a rake face of the chip discharge groove 3 and the tool body 1 The outer peripheral surface or the intersecting ridge portion formed on the outer peripheral retracting surface of the outer periphery of the tool body 1 is formed with a peripheral cutting blade 2, which is characterized in that the torsion angle α of the outer peripheral cutting blade 2 is gradually changed from the front end of the tool toward the proximal end side. increase.

A rotary cutting tool according to the first aspect of the invention, wherein the torsion angle α is set to 20 to 35°.

A rotary cutting tool according to the first aspect of the invention, wherein the torsion angle α is set to an angle difference of 1 between the tool tip end portion and the tool base end portion. ~10°.

Further, a rotary cutting tool according to the second aspect of the invention, wherein the torsion angle α is set to an angle difference of 1 between the tool tip end portion and the tool base end portion. ~10°.

Further, a rotary cutting tool according to any one of claims 1 to 4, wherein the cutting blade 4 recessed in the outer peripheral cutting blade 2 for cutting chips is along the cutting tool The predetermined spiral rotation direction is provided with a plurality of branches, and the chip breaker 4 is installed such that the spiral rotation direction intersects with the outer circumference cutter 2 at a predetermined intersection angle γ, and the intersection angle γ is oriented from the tool front end. The base end side is constant or increasing.

Further, a rotary cutting tool according to claim 5, wherein the intersection angle γ is set such that the angle of intersection γ is an angle difference between the tool tip end and the tool base end. ~15°.

A rotary cutting tool according to claim 6, wherein the diameter of the tool body 1 is set such that the diameter gradually increases from a front end of the tool toward a proximal end side.

A rotary cutting tool according to the seventh aspect of the invention, wherein the taper angle of the diameter is set to 0.5 to 4°.

Further, a rotary cutting tool according to claim 6 is a rotary cutting tool for printing a substrate having a tool diameter of 0.5 to 2 mm.

Further, a rotary cutting tool according to claim 8 is a rotary cutting tool for processing a printed circuit board having a tool diameter of 0.5 to 2 mm.

Since the present invention is configured as described above, it is a conventional rotary cutting tool in which the torsion angle of the chip discharge groove is fixed, and it is possible to maintain a good cutting process over a long distance, and is a rotary cutting tool which is extremely practical.

The embodiments considered to be suitable for the present invention will be briefly described with reference to the drawings and the functions of the present invention are shown.

The tool body 1 is brought into contact with the workpiece while rotating, and the workpiece is processed. At this time, since the torsion angle α of the outer peripheral cutting blade 2 (the chip discharge groove 3) is smaller as the tip end of the tool becomes larger, the larger the base end side is, the collapse can be suppressed, and the outer peripheral cutting blade can be prevented when the tool is pulled out from the substrate or the like. Damaged. Further, it is less likely to cause chipping on the base end side, and the workability and the fracture resistance are improved.

Specifically, the torsion angle α due to the tip end side of the tool is small, the collapse of the tool body 1 is suppressed, and in particular, the amount of collapse δ of the tip end portion of the tool is remarkably small, and when the outer shape processing is finished, the road knife is turned upward. At the time of pulling out, the contact between the peripheral cutting blade and the machined side is suppressed, and the peripheral cutting blade is prevented from being damaged. Further, the torsion angle α due to the proximal end side of the tool is large, the chip discharge property is improved, and the accumulation of chips is prevented, and the fracture resistance of the tool is improved. Further, since the torsion angle α is gradually increased from the tip end of the tool toward the proximal end side, unlike the case where the torsion angle α is simply different between the tool distal end side and the tool proximal end side, the outer circumferential cutting blade 2 is solved. The difference in the torsion angle is caused by the fact that the cutting impedance is deteriorated by the change point of the torsion angle, the accuracy of the machined surface is deteriorated, the peripheral cutting blade is damaged, or the damage of the tool itself is induced.

Further, the chips cut by the outer peripheral cutting blade 2 are guided to the chip discharge grooves 3 and discharged, but a part of the chips are moved rearward in the rotation direction of the tool through the chip breaker 4. At this time, as shown in FIG. 3, if the crossing angle γ of the outer peripheral cutter 2 and the chip breaker 4 is small, the movement of the chips is difficult, and the chip discharge property is deteriorated and broken. Therefore, for example, in order to improve the chip discharge property and improve the fracture resistance of the tool, the intersection angle γ of the outer circumferential cutting blade 2 and the chip breaking blade 4 (in the spiral rotation direction) can be configured so as not to be from the tool tip end toward the base end side. Change or increase. In this case, the tool base end side is formed to have a larger crossing angle γ than the tool tip end side, and the chip discharge property can be improved to improve the fracture resistance.

Further, in the case where the Luda knife having a small diameter is designed to have a front tapered shape in order to maintain the strength of the Luda knife, an effect equivalent to or equal to that of the straight type can be obtained, and therefore, the front tapered shape can also be designed.

[Examples]

Specific embodiments relating to the invention are illustrated in accordance with Figures 3 through 8.

The present embodiment is a rotary cutting tool which is formed on the outer circumference of the blade portion of the tool body 1 which is formed by the blade portion and the shank portion, and is formed with a plurality of spiral chip discharge grooves from the tool tip end toward the base end side. 3, the rake face of the chip discharge groove 3 and the outer peripheral surface of the tool body or the intersection ridge line formed on the outer peripheral retracting surface of the outer periphery of the tool body, the peripheral cutting blade 2 is formed; and the outer circumference is configured The torsion angle α of the cutter 2 is gradually increased from the tip end of the tool toward the proximal end side, and the diameter D of the blade portion is 0.5 to 2 mm. Further, in the present embodiment, the outer peripheral cutting blade 2 is formed at the intersecting ridge line portion so that the adjacent chip discharge grooves 3 intersect in the tool circumferential direction, that is, the face in the direction in which the chip discharge groove 3 faces the tool rotation direction is the front blade. The surface (the surface) facing the direction opposite to the direction of rotation of the tool is a peripheral retracting surface having a predetermined outer peripheral retracting angle of the outer peripheral cutting blade 2.

In addition, since the diameter D (tool diameter D) of the blade portion is less than 0.5 mm, the fracture resistance is extremely low, so that the blade breakage occurs before the outer peripheral cutter is damaged or the amount of collapse becomes a problem, and the effect described later cannot be surely exerted. . Moreover, when it is larger than 2 mm, the rigidity is increased, and the amount of collapse is small, and the effect of the later described effects cannot be reliably exhibited. In this embodiment, the diameter D is 1.0 mm.

Specifically explain each part.

The torsion angle α of the outer peripheral cutter 2 (chip discharge groove 3) is set to 20 to 35°. When the torsion angle α is less than 20°, the discharge property of the chips is deteriorated. Moreover, when it is more than 35 degrees, burrs are likely to occur, and the breaking life is shortened.

Further, the torsion angle α is set such that the angular difference between the tip end portion of the tool and the end portion of the tool base is 1 to 13°. Specifically, the torsion angle α of the outer peripheral cutter 2 is formed to gradually increase from the front end of the tool toward the base end side, and the angle of twist α of the predetermined position on the front end side of the tool and the angle of the twist angle α of the predetermined position on the base end side of the tool are formed. The difference is set to 1~13°. In the present embodiment, the angular difference between the torsion angle α at the position twice or less from the tool diameter D and the torsion angle α at the tool length position from the tip end of the tool is set to 1 to 13°. More specifically, for example, in the embodiment No. 1 (diameter: 1 mm, knife length: 6.5 mm) of Fig. 6, the torsion angle α of the position of 1.5 mm (two times or less of the tool diameter D) from the tip end of the tool The angular difference of the torsion angle α at the 6.5 mm position (the tool length position) from the front end of the tool is set to 2.5°. Further, the measurement position of the cutting angle β to be described later is also the same as the measurement position of the torsion angle α.

When the angle of twist of the twist angle is less than 1° between the tip end portion of the tool and the end portion of the tool base, the effect of improving workability and fracture resistance cannot be obtained. Further, when it is more than 10°, the change in the cutting resistance becomes large, so that it is easily broken, and therefore it is preferably 10 or less.

Further, the torsion angle α is set to be in the range of 20 to 40° at any point. In the present embodiment, the torsion angle α of the tip end portion of the tool is set to 27.5°, and the torsion angle α of the tool base end portion is set to 30°, so that the angle difference between the torsion angle α at the tool front end portion and the tool base end portion is about 2.5°. Further, the torsion angle α is preferably in the range of 20 to 35°.

Further, in the present embodiment, on the outer circumference of the tool body 1 (knife portion), in addition to the chip discharge groove 3 and the outer peripheral cutter 2, a plurality of cuts for cutting chips are provided along a predetermined spiral rotation direction. Chip cutter 4. The chip breaking blade 4 is disposed to intersect the outer peripheral cutting blade 2, and in FIG. 3, the cutting edge angle β indicates that the end of the plurality of outer peripheral cutting blades that are cut by the chip breaker is coupled to the spiral rotation of the chip breaker. The angle formed by the imaginary line B of the direction and the central axis of the tool.

Here, as shown in Fig. 3, the sum of the above-described cutting angle β and the above-mentioned torsion angle α is defined as the intersection angle γ, and the 180°-crossing angle γ is defined as the outer peripheral cutting blade angle θ.

In the present embodiment, the adjustment is performed such that the crossing angle γ is constant or increasing toward the proximal end side of the tool, so that the cutting angle β is constant, decreasing, or increasing from the tip end of the tool toward the proximal end side. Further, as shown in Fig. 3, the torsion angle α of the outer peripheral cutter 2 indicates that the right direction of the angle formed with the tool center axis is measured squarely with respect to the tool center axis, and the chip breaker is also used. The cutting angle β of 4 indicates that the left direction of the angle formed with the tool center axis is measured as a square with respect to the tool center axis. In the present embodiment, the angle difference between the intersection angle γ of the tool leading end side and the intersection angle γ of the tool base end side is 0 to 16°. For example, the embodiment No. 1 (diameter: 1 mm, knife length: 6.5 mm) of Fig. 6 is that the spiral direction of the outer peripheral cutting blade 2 is right (right twist: the twist angle α is less than 90°), and the chip breaker 4 The direction of the spiral is right (right twist: the cut angle β is over 90°). The torsion angle α of the tip end portion of the tool (the position of 1.5 mm from the tip end of the tool) is set to 27.5°, and the cutting angle β is set to 100°. Therefore, the crossing angle γ of the tip end portion of the tool is 127.5°, and the outer peripheral cutting blade angle θ is 52.5°. On the other hand, the torsion angle α of the tool base end portion (the blade length position: 6.5 mm from the tool tip end) is set to 30°, and the cutting angle β is set to 99°, so the intersection angle γ of the tool base end portion At 129°, the peripheral cutting blade angle θ is 51°. Therefore, from the tool front end toward the tool base end side, the angular difference of the torsion angle α is set to be 2.5° (30° to 27.5°), and the cutting angle β is set to be smaller by 1° (100° to 99°). The angular difference of the angle is set to be 1.5° (129°-127.5°).

When the angle difference between the intersection angle γ of the tool leading end side and the intersection angle γ of the tool base end side is greater than 15°, the peripheral cutting blade angle θ of the outer peripheral cutting blade on the tool base end side is too small, is liable to be damaged, and has low diameter stability. (It is measured to be small when the diameter is measured at the damaged portion), or burrs or breakage are likely to occur, so 15 or less is preferable.

The diameter of the tool body (knife portion) is as shown in Fig. 3, and can also be set to be fixed (straight type). To further suppress the collapse of the tool body 1, as shown in Fig. 4, it can also be set as a tool. The so-called front cone shape in which the front end gradually increases toward the base end. In this embodiment, the front tapered shape is set. The taper angle of the diameter is set to 0.5 to 5°. If the taper angle is less than 0.5°, the collapse suppressing effect of the tool body 1 will be substantially the same as that of the straight type, and the difference cannot be remarkably exhibited. Further, when it is more than 4°, the rigidity of the tool base end side becomes high, and the difference in cutting resistance between the tool tip end side and the tool base end side becomes too large, and it becomes difficult to perform uniform machining in the tool axis direction, and it is difficult to obtain a desired one. The dimensional accuracy of the processing and the roughness of the machined surface are preferred, so that it is preferably 4 or less. In this embodiment, it is set to 1.12°.

Therefore, in the conventional example (the twist angle α' is fixed and the straight type) shown in Fig. 5(a), for example, when the laminated substrate X' is processed, a significant collapse occurs (the amount of collapse of the tool tip δ) However, the amount of collapse δ at the tip end portion of the tool can be suppressed so that the torsion angle α of the outer peripheral cutter 2 is as small as the tip end of the tool to the base end side (Fig. 5(b)), further as described above. In the present embodiment (Fig. 5(c)), when the rigidity of the base end side of the tool is high and the impedance of the front end side is small, it is possible to suppress the collapse of the laminated substrate X during processing, and it is possible to pull out from the substrate. The front end of the peripheral cutting blade 2 is prevented from being damaged. Further, reference numeral 3' in the figure is a chip discharge groove, and 4' is a chip breaker. As in the present embodiment, in the case of designing the front tapered shape, as in Fig. 5(a), since the machining side is less likely to be located above the left side surface (Z portion) of the front end of the tool, the side and outer peripheral cutting blades should be processed. (2) It is difficult to contact, and the outer peripheral cutting blade 2 can be suppressed from being damaged. Therefore, an effect equivalent to or equal to that of the straight type can be obtained (see the experimental example and the eighth drawing described later).

Since the present embodiment is configured as described above, when the tool body 1 is rotated and the workpiece is brought into contact with the workpiece to process the workpiece, the torsion angle α of the outer peripheral cutter 2 (chip discharge groove 3) is obtained. Since the degree of the front end of the tool is as large as the base end side, it is possible to suppress collapse (especially, the amount of collapse δ of the tip end portion of the tool is remarkably small), and it is possible to prevent the outer peripheral cutter from being damaged when the tool is pulled out from the substrate or the like. Further, it is less likely to cause chipping on the base end side, and the workability and the fracture resistance are improved.

Therefore, the present embodiment is excellent in the practicality of maintaining a good cutting process over a long distance compared to a conventional rotary cutting tool in which the torsion angle of the chip discharge groove is fixed.

Experimental examples regarding the effects according to the present embodiment will be described below.

The results of the fracture life of the comparative example (Example 1 in Fig. 6) and the conventional example (Example 14 in Fig. 6) of the experimental conditions shown in the upper part of Fig. 7 are shown in the graph of Fig. 7 (Experimental example) 1), this embodiment (example 1 in Fig. 6) is a Luda knife having a diameter of 1.0 mm × a knife length of 6.5 mm and a taper angle of 1.12 °, and has a parameter as shown in Fig. 6, the conventional example (the first example) In the example 14), the torsion angle and the cutting angle are not changed, and the torsion angle is the base end side torsion angle of Fig. 6 and is fixed, and the cutting angle is the base end side cutting angle of Fig. 6 and is fixed. The tool body has the same diameter as the embodiment except that the diameter of the tool body is straight. Further, the diameter of the front tapered shape road blade is the diameter of the base end side in this embodiment.

Further, for each of the knives, the damaged and worn state of the outer peripheral dicing blade after 1 m cutting was observed with a digital microscope, and the results are shown in Fig. 8 (Experimental Example 2). Further, the portion surrounded by ○ in Fig. 8 is a portion where the outer peripheral cutter is damaged.

According to Figs. 7 and 8, it can be confirmed that the embodiment is not only difficult to cause damage to the outer peripheral cutting blade, but also the wear life is improved as compared with the conventional example. Therefore, it is confirmed that the present embodiment can maintain a good long distance compared to the conventional rotary cutting tool. Cutting process.

1. . . Tool body

2. . . Peripheral cutting knife

3. . . Chip discharge groove

4. . . Chip Break

α. . . Torsion angle

γ. . . Cross angle

Fig. 1 is a schematic side view showing the main part of a conventional example.

Figure 2 is an explanatory diagram of cutting impedance and collapse.

Fig. 3 is a schematic side view showing the main part of the embodiment.

Fig. 4 is a schematic side view showing the main part of the embodiment.

Fig. 5 is a schematic explanatory view showing a state at the time of processing in the present embodiment and the conventional example.

Fig. 6 is a table showing the parameters of the present embodiment and the conventional examples.

Fig. 7 is an explanatory view showing experimental conditions and experimental results of Experimental Example 1.

Fig. 8 is a photograph showing the experimental results of Experimental Example 2.

1. . . Tool body

2. . . Peripheral cutting knife

α. . . Torsion angle

β. . . Cutting angle

γ. . . Cross angle

θ. . . Peripheral cutting angle

Claims (9)

A router for processing a printed circuit board, wherein a plurality of spiral chip discharge grooves from a tool tip toward a base end side are formed on an outer circumference of the tool body, and a rake face of the chip discharge groove is An outer peripheral surface of the tool body or an intersecting ridge line formed on an outer peripheral retracting surface of the outer periphery of the tool body is formed with an outer peripheral cutting blade, wherein the torsion angle of the outer peripheral cutting blade is gradually increased from the front end of the tool toward the proximal end side. a chip breaking cutter recessed in the outer peripheral cutting blade for cutting chips, and is provided along a predetermined spiral rotating direction, and the plurality of cutting blades are predetermined in the spiral rotating direction and the outer peripheral cutting blade The manner in which the intersecting angles intersect is provided such that the crossing angle is gradually increased from the tip end of the tool toward the base end side. A road blade for processing a printed circuit board according to the first aspect of the invention, wherein the torsion angle is set to 20 to 35 degrees. A road blade for processing a printed circuit board according to the first aspect of the invention, wherein the twist angle is set such that the angle of twist between the tool tip end portion and the tool base end portion is 1 to 10 degrees. A road-drawing knife for processing a printed circuit board according to the second aspect of the invention, wherein the twist angle is set such that the angle of twist between the tool tip end portion and the tool base end portion is 1 to 10 degrees. The Luda knife for processing a printed circuit board according to any one of claims 1 to 4, wherein the intersection angle is set such that the angle of intersection between the tool tip end portion and the tool base end portion is 1.5 to 15 °. A road blade for processing a printed circuit board according to claim 5, wherein the diameter of the tool body is set such that the diameter gradually increases from a front end of the tool toward a proximal end side. A road blade for processing a printed circuit board according to the sixth aspect of the invention, wherein the taper angle of the diameter is set to 0.5 to 4°. A Luda knife for processing a printed circuit board according to the fifth aspect of the patent application, wherein the tool has a diameter of 0.5 to 2 mm. A Luda knife for processing a printed circuit board according to the seventh aspect of the patent application, wherein the tool has a diameter of 0.5 to 2 mm.