NH Series

Point autofocus probe 3D measuring instrument

Perfect solution for measuring all kinds of surface topography

NH Series solves various measurement problems

・Non-contact measurement preserves the workpiece surface
・Easily measures steep slopes and rough surfaces
・Directly measures mirror surfaces and transparant materials without surface treatments

Features

Live camera image of the measurement point

The laser probe (non-contact probe) offers “no stylus wear” which leads to non-destructive measurement of a workpiece surface. Repetitive form and areal surface texture measurements of a costly precision mold can be easily done.

Live camera image of the measurement point

The built-in CCD camera offers a live view of the laser beam spot. Image processing function* offers edge detection and circle measurement.

Large measuring area and high precision measurement

The laser probe with a radius of 0.5 μm and the precision XY scanning stage directly measure an area of several tens of millimeters down to the sub-micrometer level (measuring range: XYZ = 150 x 150 x 10 mm, scale resolution: XY = 0.01 μm, Z = 0.001 μm (model: NH-3SPs))

Straightness of the XY scanning stage ± 0.107 μm (Measuring length: 150 mm)

Flatness of the XY scanning stage: 0.437 μm (Measuring area: 150 × 150 mm)

Excellent angle tracking capability

The highly sensitive autofocus sensor captures low levels of light reflected from the workpiece surface, allowing for the direct precision measurement of steep angles and step heights.

Small diameter gear (module 0.3)

Maximum measurable angle: 87degrees

No influence of surface colors / reflectance

NH Series directly measures various types and materials of surfaces, such as coated glass with very low reflectance (approximately 0.5 %), mirror surfaces with reflectance of 90 % or greater, plastics, rubber, paper, thin films, etc.

Solution

Problem with contact probe

The stylus scratches the workpiece surface

・Cannot measure soft and sticky workpiece
・Cannot accurately set the measurement position
・Stylus wears out

NH Series solution

Non-contact measurement preserves the workpiece surface

Problem with laser microscope

The measurement range is its filed of view

・Patching is necessary for large area measurement
・Cannot program automatic measuremen

NH Series solution

Stage movable range is the measuring range which directly measures a large area

Problem with interferometry

Unable to measure large form changes

・Cannot measure slopes
・Only measures within the field of view
・Cannot measure warpage in the order of several millimeters

NH Series solution

Easily measures steep slopes and rough surfaces

Problem with focus variatio

Unable to measure mirror surface

・Cannot meausre surface roughness of mirror-finished surfaces
・Surface treatments are necessary for transparant workpiece

NH Series solution

Directly measures mirror surfaces and transparant materials without surface treatments

ISO-approved measurement method

Measurement principle comformed to the ISO standard (ISO 25178-605) offers highly reliable data.

The NH Series consists of an autofocus laser beam microscope (AF microscope) and a high precision XY scanning stage. In the figure above, the laser beam incorporated in the AF microscope passes through the objective (indicated by the red line) and forms a laser spot on the surface of the workpiece as a “probe”. The reflected laser beam from the workpiece surface passes through the objective again and forms an image on the autofocus sensor (AF sensor). The AF sensor detects the laser spot displacement in real time and adjusts the AF microscope back to the in-focus position. This measuring method, point autofocus profiling, is immune to the surface colors and reflectivity as the AF sensor detects the position of the laser spot. In addition to the conventional index measurement mode, the scan autofocus measurement mode provides high speed measurement and high precision measurement.

High correlation with international standards for roughness measurement

Point autofocus profiling (PAP) has a high correlation with roughness standards for stylus instruments and obtains highly reliable data.

Measurement method: stylus
・Roughness standard: TypeD1 (ISO5436-1)
・Calibration: PTB (Germany)
・Measurement method: stylus
・Tip radius: 5 μm
・Evaluation lenght (ln): 4 mm
・Cutoff value (λc): 0.8 mm

Measurement precision with different standards

Step master (Mitutoyo)

Specification: (10 ± 1.5) μm
Measurement result: 10.012 μm
*Measuring instrument: NH-3SP

Step Height Standards by VLSI Standards

Specification: (1.779 ± 0.011) μm
Measurement result: 1.788 μm
*Measuring instrument: NH-3SP

Unique optical system and measurement methods

Autofocus optical sytem cuts ghost and stray light

The autofocus optical system cuts out unnecessary light to achieve targetted measurement.

Transmissive surface

Secondary reflection of a Vee-groove

Edge detection function that measures xy coordinates of step heights

Many non-contact size measuring instruments use CCD cameras to detect edges by setting an image gradient as a threshold*. On the other hand, NH Series measures forms and detects edges of a workpiece by setting the ∆Z from the surface height as a threshold. Hence, NH Series is immune to color and reflectance ratio of a surface and capable of measuring a large area in high precision. This function is essential for measuring dimensions of high precision, high density and enlarging semiconductor products and optical devices.

*Image processing software (Optional) offers this funciton

Outer diameter measurement
Detects more than 3 edges and measures each radius and the central coordinate

Groove width measurement
Detect 4 or more edges Measure Radius and Center Coordinates

Measurement functions

Spatial coordinates

NH Series has various spatial coordinate construction functions to assist workpiece-oriented measurement. These auxiliary functions offer pinpoint measurements for efficient quality control.

Alignment

Reference plane creation

Point measurement

Height measurement

Curve

Edge

Circle

Width

Macro measurement

Macro measurement offers automatic measurement and evaluation by linking image processing function*, spacial coordinate function and specified point measurment function of the point autofocus probe.