Belgacem Haba

Large scale two-step selective aluminum CVD on laser patterned palladium lines

Abstract In the present report we first outline and characterize the details of uniform deposition of PdAc from an acetone solution on a large area. Then, we investigate the parameters that highly influence the thickness and quality of the laser direct-written palladium lines (spin coating speed among others). Currently, good quality and uniform patterning of laser written thin lines of Pd have been achieved on samples as large as 4 inches in diameter. The Pd lines are well resolved (minimum of 3 μm in width now) and exhibit fairly good resistivity around 30 μΩ⋯cm. They also showed good adhesion to the SiO 2 substrate as they endure repeated Scotch tape adhesion tests. Moreover, the second step of highly selective Al-CVD has been investigated under various conditions and gave rise to resistivities of about 6.5 μΩ⋯cm and 3000 A thickness for a 7 min deposition. This process stands out as very promising for packaging and high density interconnect technologies.

Novel drilling technique in polyimide using visible laser

We report a new and fast laser‐drilling technique in polyimide. This drilling process consists of two steps. First, the polyimide is irradiated with millisecond pulse of visible laser light. Second, the debris inside and around the holes are ultrasonically cleaned in water in a short time. In this report, we also analyze the emitted light originated from the laser induced polyimide decomposition that leads to the drilling. The mechanism behind the drilling is believed to be associated to a volcano‐eruption‐like behavior. This inexpensive technique provides good quality drilling, high throughput, and very promising applications in packaging technology.

Novel Technique of Laser Through-Hole Drilling in Teflon.

A novel technique of laser drilling of reinforced Teflon films with SiO2 particles is demonstrated. The new process consists of three simple steps. First, 300 A of gold is deposited on Teflon to allow laser absorption. Second, drilling is done by pulsed irradiation at a rate of one hole per pulse. At this stage the Teflon is only modified by the laser irradiation. Third, the modified Teflon is removed by ultrasonic cleaning, leaving behind clean through-holes of 50 µm in diameter. A potential drilling speed as high as 60000 holes/min with fairly high spatial resolution is the main attraction of this simple technique.

Novel technique of through-hole laser drilling in teflon

Abstract In this manuscript, we report a novel technique in laser drilling of teflon films. The new process surpasses the conventional techniques in simplicity, throughput and spatial resolution. The process consists of three simple steps. First, a thin absorbing layer (in this case 300 A of gold) is deposited on the teflon to allow for the laser absorption. Second, the drilling is laser induced at the rate of one hole per one-millisecond pulse. At this stage, the hole is not completely open and debris still fills the hole. Third, the ultrasonic cleaning in water is used to remove the modified and weakly cleaning in water is used to remove the modified and weakly bound material inside the drilled holes. This new technique is desirable for packaging technique because of its drilling speed as high as 60 000 holes per minute and its low laser equipment cost.

Laser through-hole drilling and laser cutting in teflon

We report a novel technique for laser high-speed drilling and cutting in teflon films. The new laser drilling surpasses the conventional techniques in simplicity, throughput and spatial resolution. The laser cutting and drilling process consists of three simple steps. First, a thin absorbing layer (in this case 300 Å of gold) is deposited on the teflon to allow for laser absorption. Second, the drilling is performed by pulsed-laser irradiation at the rate of one hole per pulse. The irradiation process does not completely open the holes in which debris still remain. Third, the ultrasonic cleaning in water is used to remove the modified and weakly bound material inside the drilled holes, leaving behind 50 μm diameter through holes in 25 μm thick teflon sheets. The drilling process-window is well mapped. The cutting process is obtained by fast scanning the laser beam at laser powers above a threshold value. This new technique is desirable for packaging because of its drilling speed as high as 60 000 holes per minute, its fast cutting and its low laser equipment cost.