Abstract: In the process of forming a through-hole or blind-hole at desired positions of a the substrate material, the present invention sets a drilling target position for each hole and a plurality of auxiliary drilling positions at a periphery of the drilling target position, and performs a plurality of drillings at the drilling target position and the plurality of auxiliary drilling positions. In another preferred embodiment of the present invention, a plurality of drillings are performed only at the auxiliary drilling positions per one hole at the desired position. According to the present invention, through-holes or blind-holes having several sizes of diameters can be formed by using one drilling jig under a single drilling condition. Accordingly, it is possible to efficiently produce circuit boards at low costs.

Abstract: A small drill includes one chip-discharging flute which is helically formed in the exterior surface of a cutting portion of the small drill. The small drill also includes a flute-shaped portion which is formed in the front region of the chip-discharging flute in the rotating direction, which is connected to the chip-discharging flute, and which is open at the exterior surface of the cutting portion. The core diameter ratio d/D, in percent, of the small drill is set to 60% or more, and a margin angle &thgr; thereof is set to 120° or more.

Abstract: The present invention relates to the production of an improved via for attaching electrical connection pins to printed circuit boards. The inventive via provides a connection having robust mechanical attachment and minimal capacitance effects. The via provides a wide diameter for accepting an electrical connection pin and a reduced diameter along other portions of the length of the via for reduced capacitance and reduced electrical discontinuity.

Abstract: An improved drill bit for high speed, small diameter drilling of printed circuit boards uses flute/land ratio tapering in combination with the appropriate web thickness and point, cutting or flute angles to obtain high quality, accurately positioned holes. In one embodiment, the web thickness at the tip is 15% of the drill diameter, the flute/land ratio is 2.0, the tip angle is 130.degree., the second cutting angle is 20.degree., the third cutting angle is 30.degree., the flute angle is 32.degree., the relief groove depth is 0.001", body length is 0.256" and the distance between the body end and the flute end is 0.01". Such a bit is used in connection with an air jet cooling/cleaning system and a step feed drilling method wherein the first step is between four-six times drill diameter, the second step is between two-three times the drill diameter, and the third step and subsequent steps are between 1.5-2.5 times the drill diameter.

Abstract: A drill bit for forming holes in a printed circuit board. The drill bit includes a first end including a tip for contacting the material of the circuit board. A second end of the drill bit is attached to apparatus for rotating the drill bit. A cutting edge is in the vicinity of the first end. A pressure pad is opposite the cutting edge. A flute winds upwardly about the drill bit in a helix. An angle of the helix with respect to a longitudinal axis of the drill bit varies continuously, wherein the angle is about from about 15.degree. to about 35.degree. in the vicinity of the first end and increases with increasing distance from the first end to at least from about 35.degree. to about 65.degree..

Abstract: A method for fabricating at least one via or hole in a multi-layer printed circuit board comprises separately drilling the board layers, stacking and laminating the drilled board layers utilizing conformal mapping digital imaging in a computer, and then finish drilling the holes. The invention also provides a method for correcting artwork to compensate for lamination distortion.

Abstract: An arrangement for driving a rotary tool is provided in which the tool shank is engaged and frictionally driven by the engagement of three or more drive rollers. Axial movement of the tool is accomplished by tilting the axes of the rollers as permitted by flexible portions of the shafts which drive the rollers. The tool is released by moving one roller away from the other two. A pressure foot is provided at the bottom of the assembly reciprocated by a cam arrangement to engage the workpiece when the tool is in operation. A position pick-off senses the axial position of the tool so that the tilt angle of the rollers can be controlled by a dual feedback path servo loop having an improved preconditioning circuit for its feedback position counter.

Abstract: An improved drill bit having a shank of larger diameter than the body of the drill has an intermediate section rearward of the point section of the drill of smaller diameter than the point, and a longitudinally elongated, enlarged diameter root section joining the rear end of the intermediate section to the shank. The reduced diameter of the intermediate section provides a clearance space, preventing rubbing of the wall of a hole drilled by the bit, while the enlarged diameter root section increases the resistance of the bit to breaking. An improved method of making the enlarged-root drill bit includes inclining a relieving wheel at a substantially smaller angle to the longitudinal axis of a blank than the angle at which the blank was fluted. In one embodiment having a front tapered tip made by the novel method, rearwardly directed teeth are formed at the rear plane of the drill point, by fluting and relieving steps alone, without requiring an additional machining step.

Abstract: A device and method are provided for side-drilling of catheters. The method comprises storing side-drilling hole patterns, selecting a side-drilling hole pattern, positioning the catheter at successive locations defined by the pattern, and drilling holes at the locations. The device carries out the method to side-drill catheters.

Abstract: A machine tool produces a tapered slot by moving a tool laterally of the workpiece as well as directly into it. The lateral movement is shortened at the end of each half reciprocation, so as to form the taper. The shortened stroke is achieved by use of electronic circuitry in which transducers are utilized to indicate by voltage output, the magnitude of movement of the tool into the workpiece relative to the magnitude of the movement of the tool laterally thereof and on positive or negative numerical pair being noted, deriving a further signal therefrom and utilizing it to change the direction of reciprocation.

Abstract: Disclosed is an improved back-up sheet for backing a workpiece during a small bore drilling process. The sheet also possesses electrical properties making it an ideal candidate as a laminate (reinforcing layer or bonding sheet) in the construction of multi-layer printed wiring boards. The sheet or laminate comprises the cured residue of:(a) polyphenylene oxide;(b) a bisphenol A-type epoxy resin; and(c) an amine hardener for said epxoy resin, the weight ratio of a:b+c ranging from about 1:10 to 1:2.

Abstract: A solution and a method of using it for preventing smear in the manufacture of printed circuit boards includes monoethanolamine combined with a fatty acid for neutralizing the active amine except in the presence of relatively high heat, and a surface tension reducing agent. The solution is applied to the printed circuit board as holes are being drilled. The friction of the drill bit on the printed circuit board generates heat which activates the amine allowing it to attack the inner glass epoxy walls of the printed circuit board and prevent smear.

Abstract: A rotary carbide drill for drilling clean holes in aramid fiber composites is made from a cylindrical rod having a planar elliptical end surface. The drill has a longitudinally extending arcuate flute that becomes shallower as it progresses away from the end surface. The arcuate flute is generated with a diamond wheel or disc having a periphery with a semi-cylindrical cross-section in a manner so that each of two radial segments alternate as the lead cutting surfaces, providing essentially equal wear on the segments so that frequent dressing of the wheel is eliminated.

Abstract: A multi-lip drill is proposed in which an additional auxiliary swarf flute is arranged in the core region of one or more principal swarf flutes in order to enlarge the swarf space.

Abstract: This invention is directed to a boring machine provided with a spindle supported rotatably in a spindle housing, a driving means for rotating the spindle, and a spindle feed mechanism supporting the spindle housing so that the spindle housing can be moved up and down. This boring machine includes a means for detecting the level of axial displacement of the spindle in boring motion with the detecting means not contacting the spindle, and a comparator for comparing the level of the actual axial displacement of the spindle or the thrust force applied thereto and corresponding to this displacement with a predetermined threshold level of axial displacement or a threshold level of thrust force. The spindle feed mechanism is controlled in response to the output from the comparator.

Abstract: The flute terminus or carry out of a microdrill is located spaced from cross-sectional changes of the drill and away from such areas of stress concentration and permits a slight flexing of the drill to compensate for standard production environment in efficiencies such as spindle runout, nonperpendicularity of drill to workpiece and workpiece material which is not homogeneous.

Abstract: A machining center convertible between micro and macro machining operations with elimination of reactive spring back infeed pressures in the macro machining mode.

Abstract: A hard metal drill is disclosed for drilling contact holes in multi-legend printed circuit boards formed of synthetic resin. The drill has a diameter of not more than 1.5 mm. and has main and secondary cutting edges and spiral-shaped flutes lying opposite the drill longitudinal axis. At least one of these edges has a different angle or a different legend with respect to a corresponding other edge. The amount of difference of the two cutting angles or lengths to be compared is selected such that a gap between the drill and an edge of the drill hole is at least 20 .mu.m and not more than 50 .mu.m. In order to produce such holes more readily, the two spiral-shaped flutes have different depths.

Abstract: A method is disclosed for producing accretion-free holes with a diameter of less than 1.5 mm in circuit boards made of plastic. A hard metal drill is employed having a cylindrical chucking shank and a fluted twist section. A central axis of the twist section of the drill is moved eccentrically in relation to a central axis of rotation and therefore to a central axis of the drilled hole while drilling such that a widening of the hole occurs which is at least 20/.mu.m but not more than 50/.mu.m.

Abstract: This invention provides a drill, drilling apparatus, and methods for their use, in which a plastic shank of uniform external diameter is molded onto one end of an insert made of hard drill material. The end of the insert which is encompassed by plastic has dimensions and configurations designed to prevent axial and rotational slippage of the insert inside the plastic shank when the drill is in use. The unattached end of the insert is provided with a cutting tip and drilling flutes. High speed automatic drilling and drill-changing operations are described in which a number of drills having different flute diameters, but uniform shank diameters, are used consecutively.

Abstract: An abrasive drill of small diameter is provided with a cored portion that is eccentric, i.e., lacking a substantial concentric portion, relative to the longitudinal axis of the drill. The core, regardless of shape, is located so that during drill rotation all of the surface of a workpiece within the outline of the end of the drill is abraded by some part of the rotating end of the drill. The drill composition comprises abrasive particles in a less abrasive matrix, and the core is not hollow but comprises relatively non-abrasive material. The drill is formed by deposition of matrix material entraining abrasive particles onto a taut filamentary mandrel. The mandrel preferably comprises one or more round filaments, either straight or twisted together, alongside the longitudinal axis of the drill, and may be metallic, such as copper wire or may be non-metallic, such as nylon or other synthetic polymeric textile fiber composition. The drill diameter may be on the order of a millimeter or so or smaller.

Abstract: A tool such as a drill, etc. made of a hard metal, e.g., a cemented carbide, having applied thereto a coating film of a noble metal such as gold, silver, platinum, etc. by means of an ion-plating treatment.