摘要:
A method and structure for forming a metalized blind via. A dielectric layer is formed on a metallic layer, followed by laser drilling a depression in the dielectric layer such that a carbon film that includes the carbon is formed on a sidewall of the depression. If the laser drilling does not expose the metallic layer, then an anisotropic plasma etching, such as a reactive ion etching (RIE), may be used to clean and expose a surface of the metallic layer. The dielectric layer includes a dielectric material having a carbon based polymeric material, such as a permanent photoresist, a polyimide, and advanced solder mask (ASM). The metallic layer includes a metallic material, such as copper, aluminum, and gold. The carbon film is in conductive contact with the metallic layer, and the carbon film is sufficiently conductive to permit electroplating a continuous layer of metal (e.g., copper) directly on the carbon film without need of an electrolessly plated layer underneath the electroplated layer. The laser drilling is accomplished using a laser radiation having a wavelength between about 180 nanometers and about 600 nanometers. The depression may have any cross-sectional shape and any spatial distribution of depths. As an example, the depression may include a blind via, a rectangular channel, or a combination thereof.
摘要:
Wire bond packages which mount encapsulated semiconductor chips, such as plastic ball grid array (PBGA) packages providing for the mounting of so-called flip-chips. The chips are overlaid with heat spreading perforated cap wherein the perforations are filled with an adhesive to prevent delamination caused by mismatches in the coefficients of thermal expansion, resulting in contractions which cause the entire package arrangement to warp, leading to delamination between an encapsulant and cap and resulting in failure of connect joints and the ball grid arrays.
摘要:
The present invention provides a method of creating a circuit board having burr free castellated plated through holes. In particular, the leading edge of the plated through hole, that tends to produce burr formation using conventional profiling methods, is removed or pre-profiled. The pre-profiled plated through hole is then profiled at a distance slightly off-set from the pre-profiled edge to further prevent burr formation.
摘要:
A method and apparatus for optimizing the drilling position of a multi-layer printed circuit board prior to drilling. Each board is x-rayed to determine location coordinates information of the inner layers of multi layer circuit board panels. An optimization process determines optimal locations for drilling. The board is then drilled according to the optimized coordinates. By minimizing misregistration between the drilled holes and inner layers of the multi layer semiconductor circuit board, the present invention reduces a significant cause of scrap to the circuit board industry as well as removing a major impediment to further increasing circuit density and wireability.
摘要:
The present invention provides a circuit board having burr free castellated plated through holes. In particular, the leading edge of the plated through hole, that tends to produce burr formation during conventional profiling, is removed or pre-profiled to off-set the leading edge of the plated through hole from a surface of the circuit board.
摘要:
An apparatus for fabricating holes in a thin film has an elongated holding block for holding a column of electromagnetic driving coils. The holding block acts as a single unit, and is magnetically attached to a punch diebar. The magnetic attraction between the holding block and diebar provides easy assembly and disassembly of the parts.
摘要:
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..
摘要:
Flexure means are provided for holding a tip member of an ultrasonically reciprocating element against lateral movement while freely permitting its longitudinal movement. The reciprocating element is held fixed at a nodal point distant from the tip member. The flexure means having a natural frequency substantially the same as the reciprocating element so as to resonate in concert therewith. In one embodiment, a flexible disc fixed around its periphery is centrally pierced to receive and engage the reciprocating element. In another embodiment, a plurality of elongated resonant supports are mounted at spaced radial positions on a fixture provided with a central opening through which the reciprocating element extends so that free ends of the resonant supports are directed at and engage the reciprocating element. In this embodiment, at least two of the resonant supports are adjustable toward and away from the longitudinal axis of the reciprocating element so as to properly position it. Also, at least one other of the resonant supports is biased into engagement with the reciprocating element thereby holidng the reciprocating element against the ends of the other resonant supports.
摘要:
Multiple pins are affixed in the holes of a ceramic substrate by simultaneously impacting the pins with a piston assembly which temporarily places the pins in a viscoelastic fluid state. Upon return of the pins and the resultant fluid flow to its undisturbed solid state, each pin is left with an extension that is in interlocking engaged relationship with the ceramic particles of the substrate in the region surrounding the particular holes in which the pins have been located.The piston assembly is driven by a pneumatic high pressure system which is adjustable to the number of pins being simultaneously impacted. Release of the piston assembly is delayed until the air pressure becomes stabilized prior to impact. A vacuum pressure system returns the piston to its originating position after impact whereupon the piston assembly is ready for the next impact cycle.
摘要:
A method and structure for forming a metalized blind via. A dielectric layer is formed on a metallic layer, followed by laser drilling a depression in the dielectric layer such that a carbon film that includes the carbon is formed on a sidewall of the depression. If the laser drilling does not expose the metallic layer, then an anisotropic plasma etching, such as a reactive ion etching (RIE), may be used to clean and expose a surface of the metallic layer. The dielectric layer comprises a dielectric material having a carbon based polymeric material, such as a permanent photoresist, a polyimide, and advanced solder mask (ASM). The metallic layer includes a metallic material, such as copper, aluminum, and gold. The carbon film is in conductive contact with the metallic layer, and the carbon film is sufficiently conductive to permit electroplating a continuous layer of metal (e.g., copper) directly on the carbon film without need of an electrolessly plated layer underneath the electroplated layer. The laser drilling is accomplished using a laser radiation having a wavelength between about 180 nanometers and about 600 nanometers. The depression may have any cross-sectional shape and any spatial distribution of depths. As an example, the depression may include a blind via, then the blind via may have any cross-sectional shape, such as circular or non-circular, a rectangular channel, or a combination thereof.