SPI 50T - 3D Solder Paste Inspection System

SPI 50T - 3D Solder Paste Inspection System Description:

The most reliable 3D data and 100 % inspection

Our innovative 3D laser triangulation sensor, the RSC profiles real shape of features and also provides highly robust 3D data against considerable variations of PCB color and finishing condition, solder material, paste shape, and warpage. This highest quality of 3D data backs up top level performance of SPI 50T system concerning about the reliability and accuracy. This high performance is due to PARMI’s unique signal processing technology that is implemented as hardware logic.

By virtue of the affordable profiling speed of the 3D sensor, the SPI 50T system provides 100% whole pads inspection in even fast assembly lines. The lateral resolution is set at 18 ㎛ along the X axis direction and the scan resolution along the Y axis is set at 20㎛ . This provides the system enables to inspect an area of 30㎠ per second. This utmost inspection speed with best quality 3D data differentiates the SPI 50T system from other systems and leads the SPI 50T system to the top level.

Authentic Inspection and measurement

Our intelligent vision algorithm applied to the high quality 3D data detects every kind of solder paste defects. The measurable items are height, area, volume, and positional offset that deviate from tolerance limits. And also the algorithm detects bridged pads in a very reliable manner. The remarkable design concept such as rotating the laser sheet beam against the scan direction and maintaining the small angle between laser sheet beam and camera optical axis for negligible shadow effect secure much better performance for repeatability and accuracy. Even for small CSPs and fine pitch QFPs, the Gage R&R is much less than 10% for both height and volume data.

Monitoring the printing process

The user interface of inspection program SPIworks is based on the voice of able field engineers, therefore it features intuition and easiness to field engineers. And the UI also provides diverse useful functions for printing process monitoring and analysis.

3D shape viewer

After inspecting a PCB, the operators can designate some area to see the real 3 dimensional shapes. The area could be a pad location or a component location or even the entire PCB. Due to the vivid 3D shape, the operator can get meaningful information about the screen printer. The operator can track how shapes of solder pastes are changing according to the printer parameter changing such as the squeezing direction, squeezing pressure, snap-off distance, etc. Seeing is believing! This 3D shape viewer is the best window for seeing real shapes of solder pastes.

Monitoring printing status over all pads on the current PCB

The coloring pads locations according to the magnifications of measured data (Height, Area, Volume, offset) on every pads helps the operator to know status of printed solder pastes with ease. The locations with near green color mean that the actual values are close to the target values and the locations with far from the green color are out of the tolerance limits. The operator can adjust printer parameters or give some treatment on the stencil mask until colors over entire paste locations become close to the green. Making a decision by seeing colors is very intuitive and straight forward.

Monitoring printing status over the recent PCBs

Two types of functions are supported to monitor printing process variation. For every pad locations , standard deviations(Sigma) are calculated and every pads are colored according to the sigma values. The other function named X-bar & variance chart shows mean value and variance trend for selected pads in the 10 histogram graphs. Besides these function, the fault frequency is also colored on every pad location to show how often the pad locations have made fault up to now. Operator’s correct treatment could prevent defect and secure quality of printing process. We know that it is PARMI’s unique and elegant attitude to move one more step toward valuable and useful machine for customers.

Statistical Process Control

The SPI 50T system provides the powerful SPC program named SPCworks that is based on the classical statistical process control theory. All the measured data by the SPI 50T system are saved on the SQL data base in the 50T’s computer. The SPCworks is another windows application program with network connectivity to the SQL DB. So the SPCworks could be used at any computer networked to the SPI 50T computer. After connection to the DB, the user can selects panel by designating a period, and make a subgroup composed of some pads for the SPC analysis. The supported data types are height, Area, Volume, and positional offset. The pad selection window lets the user make up a subgroup with ease and also classifies pads into components or pad shapes. The supported tools in the SPCworks are as followings.

• X-bar and X charts
• Moving range, Range, and Sigma charts
• Histogram chart
• Numeric display for Process capability analysis
• Tolerance setting

For user’s convenience for making some report, the SPCworks provides two types of file forms. The Predefined excel form can be open by Microsoft Excel program and is ready to use without user programming. To help user make up their own report form, a text file including measure data in a asci format. 

Fast teaching and easy operation

The inspection job change consists of two stages. First stage is making a teaching file. Teaching process using Gerberworks takes normally less than a half hour even in the case of complex PCBs. The Gerberworks inputs the industry standard RS274 format file to prepare a hierarchy of information on a pad, component, and array board level, that information is used during a PCB inspection. For the component level measurement and analysis, some CAD and BOM files can be imported. Teaching process using Gerberworks is done off-line. And machine setting such as tolerance setting, that is second stage, only requires 10 minutes. This extremely short job change time save customer’s valuable time.