Custom System Examples
Huntron has had the opportunity to assemble several custom prober systems based on customer provided specifications. The initial consideration is how to best automate a particular
test process and implement it in a cost effective manner. The Huntron Access and Access 2 Probers will, in some cases, require additional cabling to be added to the existing harness.
The Access DH is better suited to customization since it was designed with this mind. Several different types of control interfaces (i.e. USB, Ethernet, Firewire, etc...) are available on
the probe heads.
Below are some examples of actual custom systems assembled for customers.
Multi-point RF Injection and Measurement
Multi-point RF meassurement probe head mounted on Access 2 Prober (left) and the Prober in custom cabinet (right)This system used a custom head design added to a Huntron Access 2 Prober. The entire system was enclosed in a custom cabinet. The customer required the ability to test unpackaged
RF FET modules by precisely placing eight pins and executing the test.
Mounted on the test head are a Holsworth RF synthesizer, Aeroflex fixed coaxial attenuator, Boonton RF power sensor meter interfacing to a multi-point sping probe assembly.
The multi-point spring probe is lower to the PCB under test using a leadscrew motor assembly. This motor assembly allowed the system to handle the heavier load of the
combined assemblies mounted on the head. A version of this leadscrew design was later incorporated into the new Access DH head assemblies. Separate power and USB cables were installed into the
Access Prober cable harness for control and power.
The customer wrote their own instrument measurement software but used Huntron Workstation with Remote Control to control the test point locations and Prober movement.
Automated Oscilloscope Measurements
National Instruments USB Oscilloscope on Access Prober and waveform displayed in Huntron Workstation
This system uses full integration of an Access Prober to take and display oscilloscope measurements with Huntron Workstation using the
Huntron Workstation SDK.
The oscilloscope used is a National Instrumnts USB-5133 that is mounted in close proximity to the Access probe tip to minimize scope lead length.
An existing USB cable to the Z axis head supplied the interface and power to the oscilloscope so a minimal amount of additional modifications to the Prober
were necessary to operate.
Huntron Workstation was used for all of the database development, test point position teaching and waveform storage functions.
The oscilloscope measurements were displayed and stored directly into the Huntron Workstation software using the DLLs supplied in the Huntron Workstation
SDK. The measurements could be compared to stored measurements and used to assist in fault location on the circuit board under test. In this system, amplitude was
the only parameter compared.
The PCB under test was powered remotely and positioned within the Prober bed using an optional mounting plate and board holder system. The board holder system ensured
that the PCB remained isolated from conductive surfaces.
Access Prober Integrated with JTAG Boundary Scan
Access Prober with Boundary Scan
This system uses an Access Prober in combination with JTAG Boundary Scan tools.
When running boundary-scan tests one can easily test the connections between the devices that
have boundary-scan capabilities. Now assume a boundary-scan device is connected to a connector.
In order to test the connection from that boundary-scan device to a connector pin a second
boundary-scan driver/sensor needs to be connected to that connector pin. This is
what the prober is used to accomplish. The probe is connected to connector pin (although this could
also be other pins) and then drive/sense the probe via boundary-scan while at the same time also
driving/sensing the boundary-scan device connected to that connector. This system eliminates the need for a
bed-of-nails type interface to connect to non-boundary-scan devices for interconnect testing. The Prober provides a
moving "nail" that can be placed where it is needed.
The specific hardware used in this system are a Huntron Access Prober, JTAG JT3717 Boundary-scan Controller (installed in PC) and a JTAG JT2148 Quad Pod.
The JTAG ProVision software was used for boundary-scan control and was running simultaneously with Huntron Workstation operating through the Remote Control option.
Access Prober with Custom Probe Holder
Access Prober with Custom Probe HolderThis system was developed for a customer wishing to make specific bandwidth measurements on a powered circuit board. The customer provided the specification for the oscilloscope probe. This probe utilizes a spring probe in the tip. A custom scope probe holder that could easily be interchanged was designed to replace the stock Huntron spring probe holder. The probe was mounted on an Access Prober controlled using Huntron Workstation. The Huntron Workstation SDK was used to integrate the oscilloscope waveform measurement and display directly into the Workstation display. The PCB under test was powered using remote hardware with cabling routed to the bottom side of the PCB by removing the Access Prober base plate cover to expose the base plate cut-out. The images to the right were taken prior to shipping the Prober to the customer.
Automated Mechanical Placement
Custom Prober Head used for Mechanical Component Placement
The system shown here was one of several made for a customer who needed to place a specialized hybrid component into a custom test fixture for long term testing. The components are picked up
by the Prober Z axis head using a custom suction system and placed into a bed-of-nails type fixture that requires significant downward pressure. A long term stress test is
then carried out for several hours. The suction is routed through durable tube placed into the cable bundle of the Prober (see red arrows).
The Z axis drive was designed to handle heavier loads and have increased downforce. A leadcsrew system was used to achieve this goal.
Control of the system uses a custom software application developed by the customer using the Huntron Hardware SDK.
The image on the left shows the inside of the Z axis head mechanism. The customers fits the final pieces of the suction system to the Z axis shaft when they receive the Prober.
The image on the right shows the Z axis head with the covers installed.