Multi line cutting machine is the core equipment for precision machining of
quartz crystals (used for electronic components and optical devices),
responsible for cutting quartz crystal rods into ultra-thin chips (requiring
cutting surface smoothness Ra ≤ 0.2 μ m and line trace depth deviation ≤ 0.05 μ
m), which directly affects the efficiency of subsequent polishing processes and
the performance of finished products. If there are many scratches on the cutting
surface (with a scratch depth exceeding 0.3 μ m) and uneven depth of line marks,
it will lead to an increase in polishing volume and a product qualification rate
of less than 85%. Based on the characteristics of quartz crystals such as
brittleness, hardness, easy edge breakage, and high surface sensitivity, a
three-step troubleshooting method is summarized to quickly restore precision
cutting performance.
Step 1: Optimize cutting line configuration and wear control - core
consumables determine surface quality
Improper material, diameter, and wear condition of the cutting line are the
main causes of multiple scratches and uneven line marks.
Poor adaptability or quality defects of cutting lines: ordinary high carbon
steel wire is used, with insufficient wear resistance (service life<8 hours),
and the surface is prone to pricking and scratching; Deviation of wire diameter
exceeding 0.002mm can result in inconsistent cutting depth and uneven line marks
for a single wire; The cutting line contains impurities or has high surface
roughness, which directly scratches the surface of the quartz crystal. Replace
the diamond electroplating cutting wire (wire diameter accuracy ± 0.001mm,
surface roughness Ra ≤ 0.05 μ m) with a quartz crystal cutting specific model;
Before going online, check the appearance of the cutting line, remove any burrs
or nodules, and ensure that the wire diameter is uniform and consistent.
Cutting line wear too fast or uneven wiring: cutting line tension fluctuates
greatly, and local wear intensifies; If the spacing deviation of the cable
exceeds 0.01mm, there may be overlapping or uneven spacing of the line marks; If
the usage time exceeds 12 hours, the cutting line wear exceeds the standard, and
the cutting force decreases, it is easy to produce scratches. Stabilize the
tension at 8-10N and control the fluctuation range within ± 0.5N through a
tension controller; Calibrate the wiring mechanism to ensure precise spacing of
0.005mm; set the cutting line replacement cycle (≤ 10 hours) to avoid expired
use.
Step 2: Calibrate tension control and operating parameters - precise control
of reducing line marks
Line speed fluctuations, improper matching of feed rate and tension can
exacerbate surface defects.
Imbalance between line speed and feed speed: When the line speed is below
8m/s, the friction between the cutting line and the crystal intensifies, which
can easily cause scratches; Above 12m/s, the vibration of the cutting line is
enhanced, and the depth of the line mark fluctuates greatly; The feed rate
exceeds 0.5mm/min, the cutting load is too high, and the crystal is prone to
edge breakage and increased scratches. Through precise control of the frequency
converter, the line speed is stable at 9-11m/s, and the feed rate is controlled
at 0.3-0.4mm/min; Adopting the "gradient line speed" mode, start at a low speed
(6m/s) in the initial stage, and then increase to the target line speed after
stabilization to avoid impact damage.
Delayed or untimely tension feedback: The response time of the tension sensor
exceeds 0.1 seconds, making it unable to capture real-time changes in wire
tension; If the adjustment amplitude exceeds 0.8N, it will cause a sudden change
in cutting depth and uneven depth of line marks. Replace the high-precision
tension sensor (response time ≤ 0.05 seconds), activate the tension closed-loop
adjustment system, and immediately fine tune when the tension deviation exceeds
0.3N; Regularly calibrate the tension controller to ensure that the detection
accuracy error is ≤ 0.1N.
Step 3: Optimize cooling lubrication and tooling protection - environmental
adaptation and scratch prevention
Insufficient cooling and lubrication, improper fixture accuracy, and
environmental cleanliness can affect cutting stability.
Poor adaptation or insufficient supply of cooling lubricant: ordinary cutting
fluid is used, with insufficient lubricity (friction coefficient>0.15), which
cannot effectively isolate the cutting line from the crystal; Flow rate below
20L/min, unable to timely remove chips, chip residue scratches the surface; The
concentration is below 5%, the cooling effect is poor, and local high
temperature leads to surface deterioration of the crystal. Replace the
specialized cooling and lubricating fluid for quartz crystals (friction
coefficient<0.1, concentration 8% -10%), ensuring a stable flow rate of
25-30L/min; Install a filtration system (filtration accuracy ≤ 1 μ m) to
promptly remove chips and avoid impurities circulating and scratching.
Insufficient tooling accuracy or low environmental cleanliness: The crystal
rod is not firmly fixed (with clamping force fluctuations exceeding 2N),
slightly displaced during cutting, and uneven line marks; The flatness deviation
of the tooling table exceeds 0.005mm, resulting in a deviation of the cutting
angle of the crystal rod; The cleanliness level of the workshop is below 100000,
and dust falls into the cutting area, causing scratches. Calibrate the fixture
table with a dial gauge to ensure that the flatness deviation is ≤ 0.002mm; use
vacuum and mechanical double clamping to ensure stable clamping force without
fluctuations; Maintain a cleanliness level of ≥ 100000 in the workshop, and
install dust covers in the cutting area to avoid dust pollution.
Daily maintenance should pay attention to: checking the wear of cutting
lines, the condition of cooling and lubricating fluids, and the stability of
tension every day; Weekly calibration of line speed, feed rate, and wire layout
accuracy; Clean the filtration system and inspect the tension sensor every
month; Check the flatness of the tooling table every quarter and replace aging
seals. By implementing the above measures, the cutting surface smoothness Ra can
be reduced to ≤ 0.15 μ m, the depth deviation of line marks can be reduced to ≤
0.03 μ m, and the finished product qualification rate can be increased to over
95%. If there are still problems, it is recommended to contact the manufacturer
to optimize the compatibility of cutting lines and parameters, and match the
precision machining requirements of quartz crystals.