JP4583711B2 - Quasi-CW diode pumped solid-state UV laser system and method of using the same - Google Patents

Description

Related Applications This patent application is a U.S. provisional patent application no. Claims priority based on 60 / 275,246.

Copyright notice (c) Electro Scientific Industries, Inc. The disclosure portion of this patent document includes what is subject to copyright protection. The copyright holder has no objection to copying the patent document or the disclosure part of the patent by facsimile because the patent document is in the Patent and Trademark Office patent file or record. However, it retains all copyrights under section 1.71 (d) of the US Patent Law Enforcement Regulations.

TECHNICAL FIELD The present invention relates to a diode-pumped solid-state laser, and more particularly to a quasi-CW diode-pumped solid-state UV laser system used for forming a via (conductive through hole) in a circuit board and a processing method using these. Is.

Various types of laser systems are used to form vias point to point at target locations on workpieces such as electronic devices and printed circuit boards (PCBs). The following will be described by using a diode Pont ping solid-state ultraviolet (UV) laser system and the target workpiece as an example, the description should not be considered as limiting the scope of the invention.

Acousto-optic (A-O) Q-switched continuous wave, such as Model 5200 of Electro Scientific Industries, Inc. (ESI), including Model 210 laser of Light Wave Electronics (LWE) when forming a via using (CW) diode-pumped (DP) solid (SS) laser system, one of the pumping diode or a plurality of pumping diodes continues to run continuously. By Rutoki is to close the Q-switch at any time for new target location of the workpiece positioning system, to suppress laser emission. After the positioning system is aligned to the new target location, by releasing the Q-switch opens at a repetition rate that is expected by the laser system to generate laser output comprising one or more laser pulses.

LWE model 210, was pumped using a CW diode two 20 watts (W), to generate the UV output power of 3W at a repetition rate of 10 KHz. The CW pumping current to the diode is limited by the thermal load of the diode. For applications that guarantee stronger UV output power, more diodes or higher current / power diodes must be used, such as two 30 W diode laser bars or four 20 W diode laser bars. In that design, about 8 W of UV output power can be expected. However, using a higher pumping power increases the thermal load of the solid state laser medium. Thermal overloading of the laser medium permanently damages the diode or significantly degrades the quality of the laser beam and limits the available power. Such limitations impose significant technical challenges on the design and manufacture of laser systems.

On the other hand, other pumping methods such as pulse pumping and quasi-CW pumping are available for laser design. Electro-optic (EO) Q-switched pulsed DPSSUV lasers, such as the early version of Lambda Physics UV “Gator” model, output higher laser pulse power, but with lower pulse repetition rate . Only one UV laser pulse is generated at each pumping pulse. Since the pumping duration is limited to a few hundred microseconds (μs), the repetition rate of the laser output pulse is usually limited to 2 kHz or less. This pumping method adversely affects the via formation efficiency (throughput) and is not suitable for via formation.
The “via formation efficiency (throughput)” herein refers to the production amount or the production efficiency (efficiency) of via formation, and in this case, refers to the time required for via formation. The shorter the working time, the higher the efficiency.

Traditional quasi-CW pumping is similar to pulse pumping, but has lower peak pumping power and longer pumping duration. Pumping method This is about 1~2kHz pumping repetition can coloration speed of the pumping duration hundreds milliseconds several hundred μs based on repetition rate and duty cycle in diodes used (ms ). This pumping method allows pumping at a higher level than CW pumping because the diode “rests” (and the thermal load is reduced or stopped) whenever pumping is off. Therefore, the laser output power during the pumping time period, it is possible to increase more than the power of comparable CW pump laser. The laser power is controlled by adjusting the current for one or more diodes. However, the pumping repetition rate of this pumping method still has significant drawbacks. Typical applications in quasi-CW pumping include those that utilize long laser pulse widths and moderate peak power, such as laser bonding and laser welding.

Therefore, a laser system that includes a pumping method that promotes both higher power and faster repetition rate is desirable to increase via formation throughput.

A typical UV laser via formation system converts the fundamental wavelength of the laser in the IR region to UV using a standard frequency conversion method . For such systems, it is preferable to achieve high throughput via formation using high UV power and high pulse repetition rate. Therefore , the A-OQ switch DPSS laser system has heretofore been suitable for forming vias.

Commercial desired system, by choosing a high UV power than Rather, forming vias to "difficult for via formation" material somewhat like Luke reduce the via formation time, or copper or FR4 It was suitable to do . Therefore, high UV output power at high pulse repetition rate (several tens of kHz from several kHz) (15W from 5W) has been considered suitable.

To be useful as commercial systems, the via formation to example PCB, it is necessary to capable of forming a laser system 400 via 300 via per second. Therefore, the laser positioning system must be moved to 300 to 400 new locations per second. In general, the laser system takes less than 1 ms to form one via, but in some cases it takes more than 1 ms to move to a new location for the next via formation . Therefore, the laser ON time is actually shorter than the laser OFF time, which is quite poor use efficiency of the laser.

The present invention synchronizes the timing of quasi-CW pumping to stop or reduce pumping while the positioning system moves from one target location to the next, and CW pump while forming vias. A quasi-CW diode or lamp pump A-OQ switch solid state UV laser is provided that increases the pumping level to exceed the level . Therefore, the heat load of the average pump power and pumping diode to the laser medium is to be the same as the normal CW pumping normally available laser diodes, UV power available for via formation is increased. Quasi-CW pumping current profile be changed, it is possible to realize a profile suitable UV pulse amplitude.

Such quasi-CW diode or lamp pumped A-OQ-switched solid-state UV lasers are novel, synchronization of quasi-CW pump beam scanning also novel, the use of laser systems for such via formation Is also new.

Additional objects and advantages of the present invention will be apparent from the following detailed description of the preferred embodiment, which will be described with reference to the accompanying drawings.

Figure 1 is a simplified for forming vias in high throughput rate, pumping targeted product synchronously, and a preferred embodiment of a quasi-CW diode pumped A-OQ-switched solid-state UV laser system 10 for laser irradiation FIG . Referring to FIG. 1, the laser resonator 12 of the laser system 10 is shown with a diode 14 that pumps the laser medium 16 from the side. However, to one of ordinary skill in the art, it is possible to fold the resonator 12, the pumping method can be a "end pumping (end-pumping)", also be used other possible known arrangement the laser system 10 Obviously we can do it. The exemplary diode 14, which California, 100W quasi-CW array and 960W high-efficiency stack array of model SDL-3200 series, which is sold by SDL, Inc. of San Jose whereabouts including Murrell is limited to these is not. The exemplary solid state laser medium (16), YAG, laser medium having a composition of YLF and YVO ₄ is free Murrell. Resonator 12, IR-between the reflecting mirror 18 and a UV (third harmonic) transmission output coupler 20, an acousto-optic (A-O) Q switch 24 along the optical axis 22, the intra-cavity frequency conversion It also has a frequency doubler 26 and a frequency tripler 28. It will be apparent to those skilled in the art that the frequency conversion can be performed outside the resonator 12.

FIGS. 2A and 2B (collectively FIG. 2) are simplified graphs of exemplary waveforms of quasi-CW pumping diode current pulses or intervals 50a, 50b and 50c (collectively current interval 50) , respectively , and FIG. 2A. exemplary a-OQ-switched laser pulses 60a superimposed on the quasi-CW pumping diode current waveform is a simplified graphical illustration of an exemplary waveform of 60b and 60c (laser pulses 60 collectively). Referring to Figures 1 and 2, operation of the laser system, the laser system 10 finishes make the one via the first target point 31 of the workpiece 30, central processing unit (CPU) 32 controls the power supply 34 it allows to stop the pumping diode (or a diode current to zero), or synchronous schedule was to reduce the pumping of a low current level diode is taken. Exemplary in power supply 34 is typically a model SDL-820 for 10-15 amperes of CW laser diode driver having a 10μs current transition time, the model SDL-830 or about 150 amps peak for CW laser driver about 50 amps model SDL928 is free Murrell for the quasi-CW laser diode array driver is not intended to be limited to these. Both of these are California, the SDL, Inc. of San Jose whereabouts are selling.

Next, the positioning system 36 moves the beam output position to the new target location 31. Beam positioning system 36 preferably includes a translation stage positioner, this positioner between the target point 31 in the same workpiece 30, or a different workpiece 30, using at least two orthogonal stages can be quickly moved . In the preferred embodiment, the translation stage positioner, Y stage moves the workpiece 30, split shaft X stage moves the high-speed beam positioner and associated focusing lens (more lenses) (split-axis) and the system To do . Z-axis direction size between X stage and Y stage may also be adjustable. By positioning the mirror to adjust the optical path 22 between the laser resonator 12 and the high-speed beam positioner several times. For example, a high-speed beam positioner, it is possible to use a high-resolution linear motor and / or a set of galvanometer, the motor and / or mirrors, specific processing operations or repeatedly based on a given test or design data The processing operation can be performed. The stage and positioner can be individually controlled and moved or adjusted to move relative to each other.

Or beam positioning system 36 according to the normal vision, or beam alignment system can be operated using this alignment system, via the objective lens, or to operate in off-axis of a separate camera. Such alignment systems are well known to those skilled in the art . In one embodiment, an HRVX vision box using free library software in the positioning system 36 sold by Electro Scientific Industry is used to provide a gap between the laser resonator 12 and the target location 31 of the workpiece 30. Align . Other suitable alignment systems are also commercially available.

In addition, the beam positioning system 36 preferably uses a non-contact type small displacement sensor to determine Abbe errors due to stage pitch, wobble or rotation not indicated by on-axis position indicators such as linear scale encoders or laser interferometers. To do. Since Abbeera correction system may be calibrated to correct reference standard value, the correction is dependent only to detect small changes in the time of reading the sensor and not on the reading of the absolute accuracy of the sensor . Such an Abbe error correction system is disclosed in International Publication No. No. 1 published on July 19, 2001. WO01 / 52004A1 and U.S. Publication No. 1 published on Oct. 18, 2001. 2001-0029674A1. Corresponding US patent application no. Parts related to the disclosure part of 09 / 755,950 are also included here for reference.

Many variations of the positioning system 36 are well known to those skilled in the art, and several embodiments of the positioning system 36 are described in US Pat. 5,751,585. The ESI Model 5320 microvia drilling system, commercially available from Electro Scientific Industry, Inc., located in Portland, Oregon , is suitable for performing the positioning system 36 , which is suitable for the electronics industry. It has been used to drill holes in laser-coated copper packages . Model Series Number 27xx, 43xx, such as 44xx or 53xx, can also be used other preferred positioning system manufactured by Electro Scientific Industries of Portland, Oregon whereabouts. It will be apparent to those skilled in the art that a system having a single XY stage for workpiece positioning and an identification beam positioning and / or stationary galvanometer for beam positioning can be used. Such a system, the output pulse 40 which is focused in the UV laser system is positioned dynamically fast, use a periodic or aperiodic wide range of toolpath Ru to generate useful patterns (toolpath) file Subeku Those skilled in the art recognize that they can be programmed.

CPU32 when it reaches the positioning system 36 is a new or second target location 31, or when nearly reached, or the course and after the diode of the scheduled time interval pumping either when inhibited or reduced At some point, current is supplied to the diode 14 or the current is increased. CPU32 instructs to release the Q-switch 24 opens the Q-switch control 38 causes emits until laser pulse 60 spaced second via at a repetition rate that is expected.

The profile of the pumping current interval 50 is such that the shape of the peak power profile of the laser pulse 60 during quasi-CW pumping is flat from low to high (shown in FIG. 2A) or from high to low during the pumping period . Can be adjusted to control . Further, the current profile may be adjusted to have a different amplitude, for example, if desired, or use of a high peak power in order to form the vias in the metal layer, to form vias in the dielectric layer or you can use a low peak power. Similarly, the time period of the current pumping interval 50, the vias larger diameter so as to increase the current interval 50, the size of the to be processed via, it can be adjusted to match the depth and material. 2A and 2B, but not necessarily, while maintaining the duty cycle the same, that the laser system 10 to change the duration of current pumping intervals 50, and it is possible to change the period between the current pumping intervals 50 Show. However, the duty cycle can be varied as well if desired for the laser power profile.

The quasi-CW pumping repetition rate can easily be as high as 2 kHz. The time period between quasi-CW pumping may not be constant as long as the average heat load on the laser pumping diode 14 and / or the laser medium 16 is approximately constant or below the thermal damage level.

In one embodiment, the diode 14 and the power source 34 in the UV laser system 10 for CW pumped 5W is Ru is modified to perform a variety of current pumping. As a result, the laser system 10 can operate at a 2: 1 duty cycle at 500 Hz. The diodes 14 pump the laser medium 16 for a period of 1 ms before these diodes stop for another 1 ms. Thus , approximately twice the magnitude of current can be supplied to the diode 14 during the pumping period ( without adversely affecting the average thermal load of the diode 14 and the laser medium 16). Therefore, the laser power during the pumping period of 1ms may be more than twice the power due to the CW pump laser comparable (especially after nonlinear frequency conversion). The A-OQ switch 24 used in the laser resonator 12 is repeatedly switched to emit the laser pulse 60 at a predetermined repetition rate of, for example, 10 kHz or 50 kHz.

The workpiece 30 can be, for example, an IC chip package, MCM, capacitor, circuit board, resistor, hybrid microcircuit, or semiconductor microcircuit. For convenience, a workpiece having only four layers is described below. Conductive layer of the top and bottom, for example, aluminum, copper, gold, molybdenum, nickel, palladium, Purachiumu, silver, titanium, tungsten, metal nitrides, or to contain standard metals such as combinations thereof I can . A typical thickness of metallic layers generally varying between 9-36μm Erareru is, its thickness may be or thinner or thicker. These conductive layers are generally made of the same material.

A dielectric substrate or dielectric layer is sandwiched between conductive layers such as benzocyclobutane (BCB), bismaleimide triazine (BT), cardboard, cyanate ester, epoxy, phenol, polynomid, polytetrafluoroethylene ( Standard organic dielectric materials such as PTFE), various polymer alloys or combinations thereof may be included. Although Ru can is a typical thickness of organic dielectric layer may significantly varying thickness than general metal layer Kusuru. An exemplary thickness range for the organic dielectric layer is about 30-400 μm.

The dielectric layer can also include standard reinforcing components that can include, for example, glass fiber mats or dispersed particles woven or dispersed in aramid fibers, ceramics, or organic dielectric materials. Typical reinforcing component is generally sized to the individual filaments or particles, and / or bundles I write woven several hundred microns from 10μm to about 1-10 .mu.m. The person skilled in the art, can be introduced into the organic dielectric reinforcing component as a powder, it is clear that it is not a non-continuous and uniform. Such composite or reinforced dielectric layers generally require higher power laser processing than that required to remove the non-reinforced dielectric layer. Those skilled in the art, these various layers within the non-contiguous, non-uniform, it is also clear that not uniform height. A laminate with several layers of metal, dielectric and reinforcing material can be thicker than 2 mm.

The via diameter is preferably in the range of 25-300 μm, but the laser system 10 can form vias having a diameter as small as about 5-20 μm or larger than 1 mm. Since the diameter of the spot size you suitably removed by the laser pulse 60 is about 25-75Myuemu, the greater the via than 25 [mu] m, punching can be formed by concentric circles treatment or spiral processing. Those skilled in the art, square vias, rectangular, oval, it is clear that it is also possible to non-circular shape such as a shape or other surface features such as grooves hole.

Through-hole vias cleanly and uniformly penetrate all layers and materials of the workpiece 30 and preferably form a negligible taper from the top of the via to the bottom of the via. Blind vias do not penetrate all layers and materials and generally stop at the bottom or bottom conductive layer. Also the lower portion of the conductive layer or the bottom of the conductive layer be composed of the same metal component as the uppermost metal layer, by selecting the parameters of the laser properly, so as not to affect the conductive layer of the lower conductive layer or bottom Can be.

The laser output 40 parameters are extremely clean and sequential for various metal targets, dielectric targets and other material targets that exhibit different light absorption characteristics, removal thresholds or other characteristics for UV or visible light. drilling, i.e. chosen to facilitate via formation. The laser system output 40 parameters include an average energy per pulse greater than about 120 μJ, preferably greater than 200 μJ, measured at the work surface, preferably a spot size diameter or space principal axis less than about 50 μm, preferably Includes a diameter of about 1-50 μm and includes a repetition rate higher than about 1 kHz, preferably higher than about 5 kHz, most preferably higher than 20 kHz, preferably a wavelength between about 190-532 nm, Most preferably, it comprises a wavelength between about 250 nm and 400 nm. Preferred wavelengths especially is, 1064 nm, 532 nm, including 349nm or 266 nm, but is not limited to these wavelengths.

Suitable parameters of the laser output 40 is an attempt, about shorter pulse width than 150ns, preferably selected to avoid the influence of thermal damage by using about 40-90ns or shorter pulse width than . Those skilled in the art, the spot area of the laser pulse 60 typically is you circular, it is apparent that it is also possible to somewhat elliptical. For suitable UV laser via formation parameters, see US Pat. No. 5,593,606 and It is disclosed in the specification of 5,841,099.

Blind vias and especially large diameter of the blind via is preferably formed by a two-step process. In the first step, to remove the conductive layers of all of the target location, during the second step, the dielectric layer of all the target location is removed by the laser output action of or below the ablation threshold of the conductive layer. After removal of the uppermost conductive layers of all the target location, by defocusing the laser spot, and / or by accelerating the repetition rate and by decreasing the current to the laser pumping diode 14, a second step During this period, the laser output action can be reduced.

But for the person skilled in the art, it is clear that it is also possible to form a blind via in the process of a single step. In process of a single step of this, before the positioning system 36 is moved to the target location 31 of the next, to remove both layers of conductive and dielectric layers of each target. A single step process is suitable for forming smaller diameter vias. In a single pass process, it is more effective to maintain a fairly strong action when the laser pulse 60 begins to remove the dielectric layer. However, since the bottom conductive layer absorbs heat from the laser output 40 when the laser pulse 60 removes the dielectric layer and exposes the bottom conductive layer, damage to the bottom conductive layer has less impact. Reduced by. Thus, by gradually reducing the or pumping current gradually defocused laser spot while removing the dielectric layer, than the case of removing at a certain single power during removal period of the dielectric layer It is effectively removed at high speed and the bottom metal layer is better protected . These and other laser power schematic techniques for the via formation process are described in US Pat. 09 / 823,922 and U.S. Pat. Details are described in US 2001-0045419. US patent application no. 09 / 823,922 of the detailed description and the drawings also here to include in as a reference.

It will be apparent to those skilled in the art that many changes can be made in the details of the embodiments of the invention described above without departing from the essence of the invention. Accordingly, the scope of the invention should be determined only by the claims.

It is the simplification schematic of one Example of the quasi-CW diode pump type A-OQ switch laser which performs intra cavity 3 time frequency conversion. FIG. 6 is a simplified graph diagram of an exemplary waveform of a quasi-CW pumping diode current. FIG. 2B is a simplified graph of an exemplary A-OQ switch laser pulse superimposed on the quasi-pumping diode current shown in FIG. 2A.

Claims (27)

A method of processing at least one target material layer at a plurality of target locations on a workpiece with a laser system, the laser system comprising a solid state laser and a laser pumping diode for pumping the solid state laser, the laser The pumping power that can be supplied to the solid-state laser when the pumping diode is operated continuously has a limit determined by the heat load of the pumping diode;
Addressing the beam positioner towards a first target location on the workpiece;
Supplying a current to the laser pumping diode at a first current level to pump the solid state laser;
Actuating an intracavity acousto-optic Q-switch to generate a first laser output having at least two laser pulses at a repetition rate of at least 2 kHz from the solid state laser;
Irradiating the first target location with the first laser output to remove material of the target from the first target location;
The current supplied to the laser pumping diode is reduced to a second current level to reduce the load on the laser pumping diode, where the second current level is greater than zero current level or zero current And less than the first current level,
Addressing the beam positioner towards a second target location different from the first target location on the workpiece;
Increasing the current supplied to the laser pumping diode to a third current level to pump the solid state laser, wherein the third current level is greater than the second current level;
Actuating the Q switch to generate a second laser output having at least two laser pulses from the solid state laser at a repetition rate of at least 2 kHz;
A processing method using a laser system that irradiates the second target position with the second laser output and removes the material of the target from the second target position. Is supplied to the first current level and the first time interval, respectively the supply current to the third the laser pumping diode at a current level and third time intervals,
The supply current to the laser pumping diode at the second current level is supplied to the second time interval,
The beam positioner changes the output position to the second target location from the first target location during the second time interval,
Wherein the first laser output and the second laser output of when the current level increases, increasing the output level, and as the output level when the current level decreases to decrease, supplied to the laser pumping diode an output power level which varies as a function of the electrodeposition flows through the bell,
The laser pumping diode, during the first of said first time interval to the end of the third time interval, supplied from the laser diode to said solid laser when the the laser pumping diode was operated continuously maximum CW current level has a predetermined pulse period corresponding to a period from the first pre-Symbol first time interval to the end of the third time interval representative of the current level of the amount of obtained pumping power up in repetition rate, when the output of the solid state laser is defined as the maximum CW pump laser power at which a was pumped to the solid-state laser by the laser pumping diode by the maximum CW current level,
By the second current level to be supplied during the second time interval less than said maximum CW current level, said first and said supplied into the first and the third time interval at least one of the third current level, greater than said maximum CW current level, whereby at least one output levels of said first and said second laser output, the maximum CW pump laser output processing method using a laser system according to claim 1 to be output by the solid-state laser at a predetermined pulse repetition rate beyond. The laser system, the laser system has a via drilling efficiency is improved according to the increase in the power level of the laser output (throughput), the via formation efficiency, which occurs when operating at the maximum C W port Npureza output to exceed the vias drilling efficiency, processing method using the laser system of claim 2. Wherein any one of the first current level and the third current level, lower than said maximum CW current level, processing method using the laser system of claim 2. Wherein the first time interval and said third time interval is equal to the amount of time, processing method using the laser system of claim 2. And said first time interval and said third time different amounts of time interval, processing method using the laser system of claim 2. Is supplied to the first current level and the first time interval, respectively the current supplied to the third said laser pumping diode at a current level and third time intervals,
The current supplied to the laser pumping diode at the second current level is supplied to the second time interval,
The beam positioner, during the second time interval, and change the output position to the second target location from the first target location,
Wherein the first time interval and said third time interval is equal to the amount of time, processing method using a laser system according to claim 1. Is supplied to the first current level and the first time interval, respectively the current supplied to the third said laser pumping diode at a current level and third time intervals,
Generating a current supplied to the laser pumping diode at the second current level at a second time interval,
The beam positioner, during the second time interval, and change the output position to the second target location from the first target location,
And said first time interval and said third time different amounts of time interval, processing method using a laser system according to claim 1. The first during the time interval and the third time to supply an equal amount of current during the interval, the processing method using the laser system according to any one of claims 5-8. The processing method using the laser system according to claim 5, wherein different amounts of current are supplied during the first time interval and during the third time interval. It said second current level, the level including zero current, processing method using a laser system according to claim 1. It said second current level, the level containing enough current to generate light output from the laser pumping diode, processing method using a laser system according to claim 1 or 2. Generated in the first current level and the third, respectively at a current level current supplied to the laser pumping diode of the first time interval and the third time interval,
Generating a current supplied to the laser pumping diode at the second current level at a second time interval,
The beam positioner changes the output position to the second target location from the first target location during the second time interval,
The first current level and the third current level, respectively, during the during the first time interval and said third time interval, a first current level value and it is different from the second even without least The processing method using the laser system according to claim 1, comprising : The first current level and the third current level, respectively, during the during the first time interval and said third time interval, a first current level value and it is different from the second even without least The processing method using the laser system according to claim 2, comprising : The first current level value and the second current level value is applied during the processing of a single layer of target location material processing method using the laser system of claim 13. Increasing the first current level value than the second current level value, said first current level value applied while processing a metal layer at the target location, said second current level value The processing method using the laser system according to claim 13 or 14, wherein the method is applied while the dielectric layer at the target location is being processed. The Q-switch operates at a faster repetition rate than 20 kHz, it causes generating laser pulses, machining method using a laser system according to claim 1 or 2. The processing method using the laser system according to claim 1, wherein wavelengths of the first laser output and the second laser output are shorter than 400 nm. Wherein the first laser output and the second laser output of include 532 nm, 355 nm, YAG laser such as the wavelength of the harmonic including 349nm or 266 nm, the wavelength of the harmonic wave emitted by a YLF laser or YVO4, wherein Item 3. A processing method using the laser system according to item 1 or 2. The current supplied to the laser pumping diode at the first current level and the third current level and generates a first time interval and the third time interval, respectively,
Generating a current supplied to the laser pumping diode at the second current level at a second time interval,
The beam positioner changes the output position from the first target location during this second time interval to the second target location,
The beam positioner, during the fourth time interval is the amount different times from the time of the second time interval, and change the output position from the second target point to a third alternative target location of ,
The laser pumping diode is lower than the fourth of the first current level and the third current level during the time interval, and supplies a large fourth level of current than zero or zero, claim A processing method using the laser system according to 1 or 2. Wherein the second current level and said fourth current level and different levels, processing method using the laser system of claim 20.   The processing method using the laser system according to claim 1, wherein the first layer is removed before removing the second layer, and then the second layer is removed in the plurality of target regions. The vias are formed through more layers than the one target layer of the first target location in the plurality of target locations , and then the beam positioner addresses the second target location to form the second via. A processing method using the laser system described in 1. A laser system for processing at least one target material layer at a plurality of individual target locations on a workpiece,
A solid state laser that generates at least a first laser output and a second laser output along an optical path toward an output position;
A laser pumping diode for pumping the solid state laser during at least a first time interval and a non-overlapping third time interval;
Supplying first and third levels of current to the laser pumping diode during the first time interval and during the third time interval, the first time interval and the third time interval. A variable controllable power supply providing a second level of current less than the first and third levels of current during a second time interval between
During the first time interval, operating the solid state laser to produce the first laser output comprising at least two laser pulses at a repetition rate of at least 2 KHz, and for the third time interval An intracavity acousto-optic Q-switch that operates the solid state laser to produce the second laser output including at least two laser pulses at a repetition rate of at least 2 KHz in between.
The output position of the first laser output is addressed toward a first target location during the first time interval, and the output position of the second laser output is set to the first position during the third time interval. A beam positioner that addresses toward a second target location and changes an output position from the first target location to the second target location during the second time interval;
The power source includes the first level of current and the first time interval during the first time interval and the third time interval when the first laser output and the second laser output are generated. The beam positioner, the power supply, and the power supply to supply the second level of current to the laser pumping diode during the second time interval in changing the output position. Interface control means for operating the Q switch directly or indirectly in cooperation;
A laser system characterized by comprising: 25. A laser system according to claim 24 for performing the method of any of claims 1-23 to process at least one target material layer at a plurality of target locations on a workpiece.   A method of processing at least one target material layer at a plurality of target locations on a workpiece with a laser system, the laser system using a solid state laser medium and a pumping source for pumping the solid state laser medium The solid-state laser medium is limited in the amount of pumping power by a thermal load applied to the solid-state laser medium during continuous operation of the pumping source;
  Addressing the beam positioner towards the first target location on the workpiece;
  Supplying a current to the pumping source at a first current level during a first time interval to pump the solid state laser medium;
  Actuating an intracavity acousto-optic Q-switch during the first time interval to generate a first laser output having at least two laser pulses at a repetition rate of at least 2 kHz;
  Irradiating the first target location with the first laser output to remove material of the target from the first target location;
  Reducing the current supplied to the pumping source during a second time interval to a second current level to reduce the load on the pumping source;
  Addressing the beam positioner towards a second target location different from the first target location on the workpiece during the second time interval;
  During a third time interval, increasing the current supplied to the pumping source to a third current level to pump the solid state laser medium;
  During the third time interval, operating the Q switch to generate a second laser output having at least two laser pulses at a repetition rate of at least 2 kHz from the solid state laser;
  A processing method using a laser system that irradiates the second target position with the second laser output and removes the material of the target from the second target position.   The pumping source includes a laser pumping diode, and the first laser output and the second laser output have an output level that varies according to a current level supplied to the laser pumping diode, And the laser pumping diode has a limit determined by the heat load of the pumping diode generated by the current, so that from the beginning of the first time interval to the end of the third time interval. In the meantime, a pumping output amount that can be supplied to the laser medium from the laser pumping diode is limited, and thereby the first and second current levels are supplied by the second current level supplied during the second time interval. The first current level supplied during each of the three time intervals. And the third current level can be supplied when the laser pumping diode is operated continuously during a CW time interval corresponding to the beginning of the first time interval to the end of the third time interval. The CW current level can be exceeded, whereby the output power level of the first laser output and the second laser output at a predetermined pulse repetition rate is determined by the pump diode as the solid state laser medium. 27. The method of claim 26, wherein the power level of the maximum CW pump laser output, which is the power delivered under constant and continuous operating conditions pumped at a predetermined pulse repetition rate at the maximum CW current level, is exceeded.

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