CN104668606A

CN104668606A - PCB substrate T type hole forming method

Info

Publication number: CN104668606A
Application number: CN201510023951.5A
Authority: CN
Inventors: 李泽清
Original assignee: APCB Electronics Kunshan Co Ltd
Current assignee: APCB Electronics Kunshan Co Ltd
Priority date: 2015-01-19
Filing date: 2015-01-19
Publication date: 2015-06-03

Abstract

The invention discloses a PCB substrate T type hole forming method. A first drill and a second drill are adopted to perform primary drilling and secondary drilling on a substrate; the diameter of the first drill is larger than that of the second drill; according to the primary drilling, the first drill is adopted to drill a blind hole on the substrate; according to the secondary drilling, the second drill is adopted to drill a through hole in the center of the blind hole; the blade angle of the first drill ranges from 170 DEG C to 180 DEG C. The T type hole is formed in a twice drilling manner, the height difference is formed between the center of the T type hole and the edge of the T type hole, since the first dill adopts the blade which is in a normal shape and which is provided with the angle ranging from 170 DEG C to 180 DEG C, the height difference between the center of the T type hole and the edge of the T type hole is smaller than 0.1 mm, namely an allowed range; thus, according to the T type hole structure and function, the same effect of the T type hole can be achieved, since the conventional drill is adopted, cost is reduced greatly, the difficulty in drilling form the conventional drill is low, and the machining control difficulty of the T type hole is lowered greatly.

Description

The T-shaped hole forming method of PCB substrate

Technical field

The invention belongs to field of printed circuit board fabrication, be specifically related to a kind of T-shaped hole forming method of substrate.

Background technology

The hole that PCB substrate is bored is generally circular port, and its processing technology difficulty is also little, only need select the drill bit of suitable types.At present, aluminium substrate boring is all adopt basil degree to be the bit drills screw of 155 °, but, along with the emergence of micro projector, its volume size requirements for projecting apparatus is very harsh, make every effort to exhaust minimum as much as possible most thinning, this just requires that the screw of aluminium base must be countersunk screw holes, namely the T-shaped hole that section is T-shaped, after making screw closure, its major part sinks in screw, to reduce aluminium base integral thickness, the processing and forming in T-shaped hole is very special, conventional drill bit machine-shaping can not be used, need to carry out drilling via formations with cross section special T-shaped brill A as shown in Figure 1, but various aspects of performance parameter is all unqualified at home at present for this T-shaped brill, purchased from Taiwan at present, its procurement price often props up 3300 New Taiwan Currencies (about RMB 650 yuan), price is about 20 times of normal drill bit, price is high, this just causes T-shaped brill consumption to become a no small cost, and the operating procedure of this T-shaped brill controls very strict, due to its chip removal, heat extraction performance is not good, all that requirement is high for time of contact of T-shaped brill and hole wall and drilling speed, Drilling operation difficulty is larger.

Summary of the invention

In order to solve the problem, the invention provides the T-shaped hole forming method of a kind of PCB substrate, the T-shaped hole forming method of this PCB substrate by the common drill bit of employing two kinds of different-diameters at twice Drilling operation mold T-shaped hole, reduce difficulty of processing and the cost of T-shaped hole forming.

The present invention in order to the technical scheme solving its technical problem and adopt is:

The T-shaped hole forming method of a kind of PCB substrate, adopt a drill bit and No. two drill bits to be taken up in order of priority once to hole and secondary drilling to substrate, the diameter of a described drill bit is greater than the diameter of described No. two drill bits, described once boring is with drill bit drilling blind hole on substrate, described secondary drilling is that the basil degree of a described drill bit is 170 °-180 ° with No. two drill bits at described blind hole centre drill through hole.

The present invention in order to the further technical scheme solving its technical problem and adopt is:

It is preferred that the basil degree of a described drill bit is 175 °.

It is preferred that the total depth in described T-shaped hole is 1.20 millimeters, described blind hole depth is 0.60 ± 0.10 millimeter.

It is preferred that the diameter of a described drill bit is 4.05 millimeters, the diameter of described No. two drill bits is 1.60 millimeters.

It is preferred that described PCB substrate is aluminium base.

It is preferred that a described drill bit is two cutting drill heads.

It is preferred that described No. two drill bits are two cutting drill heads.

It is preferred that the basil degree of described No. two drill bits is 155 °.

The invention has the beneficial effects as follows: the T-shaped hole forming method of PCB substrate of the present invention, adopt a drill bit and No. two drill bits to be taken up in order of priority once to hole and secondary drilling to substrate, the diameter of a drill bit is greater than the diameter of No. two drill bits, once boring is with drill bit drilling blind hole on substrate, secondary drilling is at blind hole centre drill through hole with No. two drill bits, the basil degree of a drill bit is 170 °-180 °, the present invention goes out T-shaped hole by the mode machine-shaping of twice boring, although the center and peripheral in T-shaped hole has some differences in height, but because a drill bit have selected the special drill bit at 170 °-180 ° of the common but basil degree of shape, so the difference in height of the center and peripheral in T-shaped hole is within 0.1 millimeter, in allowed limits, therefore, with regard to T-shaped hole structure and function, the effect same of T-shaped boring can be reached, and owing to have employed the drill bit of common shape, cost reduces greatly, difficulty again due to common shape bit bore is lower, greatly reduce the machining control difficulty in T-shaped hole.

Accompanying drawing explanation

Fig. 1 is the T-shaped brill sectional schematic diagram of prior art;

Fig. 2 is the blind hole sectional schematic diagram after the present invention once holes;

Fig. 3 is the T-shaped pore cross section schematic diagram after secondary drilling of the present invention.

Detailed description of the invention

Below by way of specific instantiation, the specific embodiment of the present invention is described, those skilled in the art can understand advantage of the present invention and effect easily by content disclosed in the present specification.The present invention also can be implemented in further, different ways, that is, not departing under disclosed category, can give different modifications and change.

Embodiment: the T-shaped hole forming method of a kind of PCB substrate, adopt a drill bit and No. two drill bits to be taken up in order of priority once to hole and secondary drilling to substrate, the diameter of a described drill bit is greater than the diameter of described No. two drill bits, described once boring is with drill bit drilling blind hole on substrate, after once holing as shown in Figure 2, described secondary drilling is with No. two drill bits at described blind hole centre drill through hole, after secondary drilling as shown in Figure 3.

The basil degree of a described drill bit is 175 °, and this basil degree is best angle.Actually add man-hour, the common shape drill bit with the basil degree between 170 °-180 ° is all feasible, but do not advise that employing basil degree is the drill bit of 180 °, basil degree less than 170 ° can cause the height difference H of T-shaped hole centerand edge excessive, basil degree 180 ° and above, can cause drill bit resistance too disaster down to bore.

The total depth in described T-shaped hole is 1.20 millimeters, and described blind hole depth is 0.60 ± 0.10 millimeter.

The diameter of a described drill bit is 4.05 millimeters, and the diameter of described No. two drill bits is 1.60 millimeters.

Described PCB substrate is aluminium base.

A described drill bit and No. two drill bits are all two cutting drill heads.

The basil degree of described No. two drill bits is 155 °.

Claims

1. the T-shaped hole forming method of PCB substrate, it is characterized in that: adopt a drill bit and No. two drill bits to be taken up in order of priority and substrate once holed and secondary drilling, the diameter of a described drill bit is greater than the diameter of described No. two drill bits, described once boring is with drill bit drilling blind hole on substrate, described secondary drilling is that the basil degree of a described drill bit is 170 °-180 ° with No. two drill bits at described blind hole centre drill through hole.

2. the T-shaped hole forming method of PCB substrate as claimed in claim 1, is characterized in that: the basil degree of a described drill bit is 175 °.

3. the T-shaped hole forming method of PCB substrate as claimed in claim 1, is characterized in that: the total depth in described T-shaped hole is 1.20 millimeters, and described blind hole depth is 0.60 ± 0.10 millimeter.

4. the T-shaped hole forming method of PCB substrate as claimed in claim 1, it is characterized in that: the diameter of a described drill bit is 4.05 millimeters, the diameter of described No. two drill bits is 1.60 millimeters.

5. the T-shaped hole forming method of PCB substrate as claimed in claim 1, is characterized in that: described PCB substrate is aluminium base.

6. the T-shaped hole forming method of PCB substrate as claimed in claim 1, is characterized in that: a described drill bit is two cutting drill heads.

7. the T-shaped hole forming method of PCB substrate as claimed in claim 1, is characterized in that: described No. two drill bits are two cutting drill heads.

8. the T-shaped hole forming method of PCB substrate as claimed in claim 1, is characterized in that: the basil degree of described No. two drill bits is 155 °.