4.3 Self calibration and linearity verification of load sensors
The Noxin DAGE 4000 supports two calibration modes:
Mode 1: Traceability calibration using standard weights
The operator selects the sensor to be calibrated and installs a dedicated hook on the force measuring end.
Load certified standard weights in order (e.g. 2g, 5g, 10g, 20g, 50g, accuracy level F1 or above).
The software records the output code value corresponding to each weight and automatically fits a polynomial calibration curve with the highest order up to 7 degrees.
Calibration information is directly written into the internal EEPROM of the sensor, and a printed report with a UKAS traceability statement can be generated.
Mode 2: Quick verification without weights
For daily inspections, users can choose the "electronic calibration" function. The system injects known equivalent electrical signals into the sensor bridge through a built-in precision resistor network to simulate standard force input.
This mode can quickly verify the linearity of the sensor within 30 seconds and determine whether it is still within the tolerance range. Although it cannot replace the legal traceability of weight calibration, it is sufficient for daily functional confirmation before class starts.
4.4 Calibration Fixtures and GR&R Identification
For customers who require Measurement System Analysis (MSA), Norsen DAGE provides a dedicated calibration fixture kit. This fixture contains multiple metal blocks with fixed geometric dimensions (such as 1mm high solder balls, 0.5mm long gold wires, etc.), which can be repeatedly installed at the same position on the XY worktable. By continuously measuring the same standard part more than 20 times and using the built-in GR&R calculation template, the repeatability and reproducibility of the equipment can be quickly calculated. Typical results show that the% GR&R of the 4000 system is typically below 10%, meeting the stringent requirements of automotive electronics (IATF 16949) and medical equipment manufacturing.
Detailed explanation of core testing applications
Based on the precise mechanical and control foundation mentioned above, the Norsen DAGE 4000 is capable of performing various industry standard tests. The following are four typical application scenarios and their key parameter settings.
5.1 Cold ball drawing
Applicable objects: Lead free solder balls in chip level packaging (CSP) or ball grid array (BGA), especially when there is bottom filling glue below the solder balls, conventional ball pushing can easily cause premature cracking of the glue layer, while cold ball pulling can directly evaluate the bonding strength between the solder balls and copper pads from the vertical direction.
Operation process:
Select a dedicated "hook and loop style claw" with slight serrations on the inside, which can firmly bite the upper hemisphere of the solder ball.
Set the drawing speed to 2mm/s (to avoid brittle fracture caused by impact load).
The maximum pulling force can reach 10kg (requires the use of a 10kg sensor).
After the test is completed, the fracture modes are usually divided into: ductile fracture inside the solder ball (qualified), IMC layer brittle fracture (requiring optimization of reflow curve), and copper pad peeling (PCB quality issue).
Compliant with standards: JETTA EIAJ ET-7407 and JEDEC JESD22-B115A.
5.2 Chamber Shear
Applicable object: Convex points in ultra-thin chips or inverted chips. Due to the extremely small spacing between adjacent convex points (<100 μ m), traditional flat cutting knives are prone to deformation and short circuiting of adjacent convex points.
Technical characteristics:
Use a V-shaped or U-shaped section shear blade, only in contact with the top area of the solder ball, with the blade tip extending between adjacent rows of solder balls.
Set the cutting height to 30%~40% of the original height of the solder ball to avoid the blade crushing the sphere.
The recommended shear speed is 1mm/s, which makes it easier to capture the maximum shear force.
The cavity shear can provide the maximum possible shear force value without damaging the surrounding structure, especially suitable for fan out wafer level packaging.
5.3 Vector Pulling
Application scenario: External pins (such as TQFP, LQFP) in lead frame packaging, which may experience interface delamination after bending testing or thermal cycling. Traditional vertical drawing cannot simulate the actual direction of force.
Implementation method:
The equipment is equipped with a rotatable pulling module, and the pulling hook can apply tension at any angle of 0 °~90 ° in the XZ plane.
The operator first selects the edge of the target pin under the microscope, and then sets the pulling direction (for example, at a 45 ° angle to the extension direction of the pin).
The Z-axis drives the hook to move along the set vector while recording the force displacement curve.
Vector drawing can effectively expose the bonding defects between the lead and the plastic package, and is commonly used in failure analysis laboratories.
5.4 Regional cutting
Background: In advanced BGA or CSP packaging, solder balls are arranged in multiple rows and high-density arrays (such as 0.35mm pitch, 10 rows x 10 columns). The traditional method requires ball by ball cutting, which is extremely inefficient.