WO2017076092A1

WO2017076092A1 - Drill bit for drilling pcb

Info

Publication number: WO2017076092A1
Application number: PCT/CN2016/093911
Authority: WO
Inventors: 郭强; 付连宇
Original assignee: 深圳市金洲精工科技股份有限公司
Priority date: 2015-11-04
Filing date: 2016-08-08
Publication date: 2017-05-11
Also published as: CN105562788B; CN105562788A

Abstract

A drill bit for drilling a PCB comprises a body (10). One end of the body (10) is a drill tip, and a groove and breadth ratio constant segment and a groove and breadth ratio alternating change segment are sequentially disposed from the end where the drill tip is located to the other end of the body (10). A long spiral groove (101) and a short spiral groove (102) that are spirally surrounding and that are not intersected are formed in the outer side of the body. The groove and breadth ratio of each of the long spiral groove (101) and the short spiral groove (102) is constant at the groove and breadth ratio constant segment. The groove and breadth ratio of each of the long spiral groove (101) and the short spiral groove (102) changes alternately at the groove and breadth ratio alternating change segment. The short spiral groove of the groove and breadth ratio constant segment is connected to a staggered groove staggered with the short spiral groove. In the drill bit for drilling a PCB, the double-spiral-groove non-intersection design is used, the groove and breadth ratio alternately changes on the rear section of the drill bit, the two grooves discharge cuttings independently, the drill bit is unlikely to be blocked by the cuttings, and the cutting temperature can be controlled in a small range. In addition, the area of a cross section entity of the spiral groove and the core thickness taper can be increased, the bend resistance strength of the drill bit is improved, the hole site machining precision is high, and the machining quality of a drilled hole is good.

Description

Drill bit for PCB board drilling

Technical field

[0001] The present invention belongs to the technical field of drill bit structures, and more particularly to a drill bit for drilling a PCB board.

Background technique

[0002] At present, electronic device motherboards are becoming smaller and smaller, and chips are highly integrated and densely packed, which places higher demands on the positional accuracy of printed circuit board (PCB) holes that connect chip pins. Different designers have multiple angles and ways to improve the drilling accuracy of PCB micro-drills. Designers generally believe that for micro-drilling, the hole accuracy of drilling depends mainly on the stiffness of the drill bit, specifically, the cross-sectional shape and drilling. Factors affecting stiffness such as core thickness, spiral groove angle, and edge length.

[0003] Japanese scholar Xing Xingyi has adopted a method of changing the helix angle and tapping the core taper to provide a hole drill with a small hole diameter of 0.4 mm or less, which is excellent in hole position accuracy, and has excellent practicability. Hole tool. The above design for the micro-drill structure parameters has not yet got rid of the traditional design concept. However, the optimization of the traditional drill bit parameters has caused a bottleneck in the improvement of the drilling performance, and it is necessary to start from the overall structure of the drill bit and carry out structural improvement.

[0004] Yuki Hideo proposed a new structural drill with a non-central symmetry of the double flutes relative to the center of rotation. The first chip flute is used to ensure the wall thickness (rigidity) structure. Of course, the main cutting edge of the drill bit. There is also only one, the other chip flute is non-centralally offset with respect to the first flute, does not form the main cutting edge, does not have a cutting action, and its groove length is smaller than the first flute groove length. The wind is arranged by providing one main flute and one or more auxiliary flutes, wherein the auxiliary flutes are in the 50%~95<3⁄4 part of the main flute length and the main row The flute connection setting enables stable drilling. However, the asymmetric design of the double spiral groove relative to the center and the intersection of the middle and rear spiral grooves have an adverse effect on the drilling hole accuracy and the cuttings discharge. Asymmetric design Because the tip of the drill is offset, the boring is prone to yaw, and chip clogging is prone to occur in the blind groove, resulting in excessive cutting temperatures and severe wear on the edge of a single main cutting edge. In the middle and rear section spiral groove intersection design, the front end of the bit meets easily due to insufficient rigidity, resulting in low hole position accuracy, and the chip removal at the two-slot intersection is likely to cause congestion, and the chips are not easily discharged, which affects the processing quality of the hole.

technical problem [0005] The object of the present invention is to overcome the above-mentioned deficiencies of the prior art, and to provide a drill bit for drilling a PCB board, which has good rigidity, easy chip discharge, and high hole machining precision.

Problem solution

Technical solution

[0006] The technical solution of the present invention is: a drill bit for drilling a PCB board, comprising a body, one end of the body is a drill tip, and the body is provided with a groove width from one end of the drill tip to the other end. The outer side of the body is provided with a long spiral groove and a short spiral groove which are spirally wound and do not meet, and the short spiral groove and the short spiral groove are constant in the groove width ratio. The groove width ratio is constant, and the long spiral groove and the short spiral groove alternately change in the groove width ratio of the groove width to the constant groove, and the groove width is connected to the short spiral groove of the constant segment to be misaligned with the short spiral groove The wrong slot.

[0007] Optionally, the groove width is alternately changed, the long spiral groove and the short spiral groove have alternating first width and second width, and the first width is greater than the first Two widths; the groove width is constant, the long spiral groove and the short spiral groove have a constant width, and the second width is greater than 0 mm and smaller than the constant width.

[0008] Optionally, the length of the groove width is greater than the length of the constant section and is less than 50% of the long spiral groove.

[0009] Optionally, the groove width ratio of the groove width to the constant segment is greater than or equal to 1; and the groove width ratio of the groove width to the alternating segment is greater than 1.

[0010] Optionally, the wrong slot is engaged with the short spiral groove, and the groove width of the wrong groove is equal to or larger than the groove width of the short spiral groove.

[0011] Optionally, the width of the groove width of the wrong groove and the width of the groove width of the short spiral groove are greater than

0 and less than 0.8 times the groove width of the short spiral groove.

[0012] Optionally, the core has a taper thickness equal to or greater than a core taper of the long spiral groove.

[0013] Optionally, the wrong groove is parallel to the long spiral groove, and the groove width of the wrong groove is equal to or smaller than the groove width of the long spiral groove.

[0014] Optionally, the short spiral groove and the wrong groove have a clear boundary line.

[0015] Optionally, the slot length of the short spiral groove is greater than or equal to the drill bit UC segment.

Advantageous effects of the invention

Beneficial effect In the drill bit for drilling a PCB board provided by the embodiment of the present invention, the long spiral groove and the short spiral groove have a constant groove ratio of the groove width to the constant section, and the long spiral groove and the short spiral groove are The groove width alternates with a groove width ratio of the constant section, and the groove width is connected with a short spiral groove of the constant section to be offset from the short spiral groove. In this way, the double spiral groove non-intersection design is adopted. In the latter part of the drill bit, the ratio of the groove width is alternately changed, the double groove is independently discharged, the chips are not easily blocked, the cutting temperature can be controlled in a lower range, and the spiral groove cross section can be increased. The area of the solid and the taper of the core thickness increase the bending strength of the drill bit, the machining accuracy of the hole position is high, and the machining quality of the drilling hole is good.

DRAWINGS

In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings to be used in the embodiments will be briefly described below. It is obvious that the drawings in the following description are only some embodiments of the present invention, Those skilled in the art will be able to obtain other drawings based on these drawings without any creative work.

Figure 5 (a) is a schematic cross-sectional view of B-B in Figure 4;

Figure 5 (b) is a schematic cross-sectional view of A-A in Figure 4;

Figure 5 (c) is a schematic cross-sectional view of C-C in Figure 4;

Fig. 6 is a plan view showing a drill bit for drilling a PCB board having a spiral groove width profile according to an embodiment of the present invention.

detailed description

The present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It is understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

It should be noted that when an element is referred to as being "fixed" or "in" another element, it can be directly on the other element or possibly the central element. When an element is referred to as being "connected" to another element, it can be either directly connected to the other element or the. Replacement page (Article 26) [0027] It should also be noted that the left, right, upper, lower, and the like orientations in the embodiments of the present invention are only relative concepts or reference to the normal use state of the product, and should not be considered as having Restrictive.

[0028] As shown in FIG. 1 and FIG. 2, a drill bit for drilling a PCB board includes a body 10, one end of the body 10 is a drill tip, and the body 10 is self-described. One end of the drill tip is sequentially provided with a groove width constant section L1 and a groove width ratio alternating section L2, and the outer side of the body 10 is provided with a long spiral groove 101 and a short spiral groove 102 which are spirally wound and do not meet, The ratio of the groove width of the long spiral groove 101 and the short spiral groove 102 to the groove width constant section L1 is constant, and the ratio of the groove width of the long spiral groove 101 and the short spiral groove 102 to the groove width is constant. The groove width is smaller than the short spiral groove 102 of the constant segment L1, and the groove 103 is misaligned with the short spiral groove 102. In this way, the double spiral groove non-intersection design is adopted. In the rear section of the drill bit, the ratio of the groove width is alternately changed, the double groove is independently chipped, the chips are not easily blocked, the cutting temperature can be controlled in a lower range, and the spiral groove cross-section entity can be increased. The area and the thickness of the core increase the bending strength of the drill bit, the machining accuracy of the hole position is high, and the machining quality of the drilling hole is good.

[0029] Specifically, in the groove width ratio alternating section L2, the long spiral groove 101 and the short spiral groove 102 have alternating first width wl and second width w2, and the first width The width wl is greater than the second width w2. In the groove width constant section L1, the long spiral groove 101 and the short spiral groove 102 have a constant width w3. In the figure, w4 is the groove width. The second width w2 is greater than 0 mm and less than the constant width w3. The first width wl can be greater than or equal to the constant width w3, and the drill has good bending strength and good chip removal effect.

[0030] Specifically, the groove width is longer than the length of the constant section L1 and is less than 50% of the long spiral groove 101 or the short spiral groove 102, and the bit has good bending strength and good chip removal effect.

[0031] Specifically, the groove width ratio of the groove width to the constant segment L1 is greater than or equal to 1; the groove width ratio of the groove width to the alternating change segment L 2 is greater than 1, and is improved under the condition of ensuring the bending strength of the drill bit. Chip removal effect.

[0032] Specifically, the wrong groove 103 is engaged with the short spiral groove 102, and the groove width of the wrong groove 103 is equal to or larger than the groove width of the short spiral groove 102 to improve the processing quality.

Specifically, the center of the groove width of the offset groove 103 and the center of the groove width of the short spiral groove 102 have a width greater than 0 and less than 0.8 times the groove width of the short spiral groove 102.

[0034] Specifically, the core groove of the wrong groove 103 is equal to or larger than the core thickness taper of the long spiral groove 101, the core thickness value is small, the spiral groove is large, and the taper is thick, and the core thickness taper is the drill tip. The core thickness is divided by the core thickness at the end of the groove.

[0035] Specifically, the wrong groove 103 is parallel to the long spiral groove 101, and the groove width of the wrong groove 103 is equal to or It is smaller than the groove width of the long spiral groove 101.

[0036] Specifically, the short spiral groove 102 and the wrong groove 103 have a clear boundary line.

[0037] Specifically, the slot length of the short spiral groove 102 is greater than or equal to the drill bit UC segment.

[0038] In a specific application, the long spiral groove 101 and the short spiral groove 102 may be ground first, and then the short spiral groove 102 may be continued to the long spiral groove 101 groove length by the wrong groove 103. Then the drill bit sharpens, the drill bit grinds back and cuts the UC.

[0039] The drill bit for drilling a PCB board provided by the embodiment of the present invention has a groove width ratio of the long spiral groove 101 and the short spiral groove 102 to the groove width constant section L1, the long spiral The groove 101 and the short spiral groove 102 alternately change in the groove width ratio of the groove width constant section L1, and the groove width is connected to the short spiral groove 102 of the constant section L1 with a wrong groove which is offset from the short spiral groove 102. 103. In this way, the double spiral groove non-intersection design is adopted. In the rear section of the drill bit, the ratio of the groove width is alternately changed, the double groove is independently chipped, the chips are not easily blocked, the cutting temperature can be controlled in a lower range, and the spiral groove cross-section entity can be increased. The area and the thickness of the core increase the bending strength of the drill bit, the machining accuracy of the hole position is high, and the machining quality of the drilling hole is good.

The above description is only the preferred embodiment of the present invention, and is not intended to limit the present invention, and any modifications, equivalent substitutions or improvements made within the spirit and principles of the present invention should be included in the present invention. Within the scope of protection of the invention.

Claims

Claim

A drill bit for drilling a PCB board, comprising a body, wherein one end of the body is a drill tip, wherein the body is provided with a groove width ratio constant section and a groove width from one end of the drill tip to the other end The outer side of the body is provided with a long spiral groove and a short spiral groove which are spirally wound and do not meet each other, and the groove ratio of the long spiral groove and the short spiral groove to the groove width is constant. The long spiral groove and the short spiral groove alternately change in the groove width ratio of the groove width to the constant section, and the groove width is connected with the short spiral groove of the constant section to have a wrong groove which is wrong with the short spiral groove.

The drill bit for drilling a PCB board according to claim 1, wherein the groove width is alternately changed, and the long spiral groove and the short spiral groove have alternating first width and second width Width, and the first width is greater than the second width; the groove width is constant, the long spiral groove and the short spiral groove have a constant width, and the second width is greater than 0 mm and smaller than Said constant width.

A drill bit for drilling a PCB board according to claim 1, wherein the groove width is longer than the constant length of the drill UC section and smaller than 50% of the long spiral groove.

The drill bit for drilling a PCB board according to claim 1, wherein a groove ratio of the groove width to the constant section is greater than or equal to 1; and a groove width ratio of the groove width ratio is more than 1 .

The drill bit for drilling a PCB board according to claim 1, wherein the groove is engaged with the short spiral groove, and the groove width of the groove is equal to or larger than the groove width of the short spiral groove.

[Claim 6] The drill bit for drilling a PCB board according to any one of claims 1 to 5, characterized in that

The width of the groove width of the offset groove and the width of the center of the groove width of the short spiral groove are greater than 0 and less than 0.8 times the groove width of the short spiral groove.

[Claim 7] The drill bit for drilling a PCB board according to any one of claims 1 to 5, characterized in that

The core groove of the wrong groove is equal to or larger than the core thickness taper of the long spiral groove.

[Claim 8] A drill bit for drilling a PCB board according to any one of claims 1 to 5, characterized in that

The wrong groove is parallel to the long spiral groove, and the groove width of the wrong groove is equal to or smaller than the The groove width of the long spiral groove.

[Claim 9] The drill bit for drilling a PCB board according to any one of claims 1 to 5, characterized in that

The short spiral groove and the wrong groove have a clear boundary line.

[Claim 10] The drill bit for drilling a PCB board according to any one of claims 1 to 5, characterized in that

The slot length of the short spiral groove is greater than or equal to the UC segment of the drill bit.