What preparations should be made in advance to test IC chips? Detailed explanation of the whole process

Date：2022-02-16 18:14:27Views：1249

When testing the chip, pay attention not to cause a short circuit between the pins. The short circuit at any moment can be caught, resulting in the chip burning out. Failure analysis is an important part of chip testing. Whether for mass-produced samples, design links or customer returned products, failure analysis can help reduce costs and shorten the cycle.

Common failure analysis methods include decap, X-ray, IV, Emmi, FIB, SEM, EDX, probe, OM, RIE, etc. because failure analysis equipment is expensive, most demand units can not match or complete the required equipment. Therefore, it is also a good choice to use external forces and open resources to complete their own analysis. What preparations should we make in advance to test IC chips? Let's take a look at the relevant introduction:

1、 Decap: write down the sample size, quantity, packaging form, material, unsealing requirements and subsequent tests.

1. IC unsealing (front / back) QFP, QFN, sot, to, dip, BGA, cob, etc

2. Sample thinning (except ceramics and metals)

3. Laser marking

4. Chip unsealing (front / back)

5. IC etching and plastic package removal

2、 X-ray: write down the sample size, quantity, material (high density can be seen, low density can be directly penetrated), key observation area and accuracy.

1. Observe electronic components such as semiconductors, resistors and capacitors in different packages such as dip, SOP, QFP, QFN, BGA and flipchip, as well as small PCB printed circuit boards

2. Observe the chip size, quantity, stacking die and wire binding inside the device

3. Observe chip crack, uneven dispensing, broken wire, grounding, internal bubbles and other packages

Defects, as well as solder ball cold welding, false welding and other welding defects

3、 IV: write the number of pigging pins, packaging form, power on mode, voltage and current limit range. It needs to be confirmed in advance to build a suitable analysis environment. If the sample is not suitable, you don't have to go in vain.

1.Open/Short Test

2.I/V Curve Analysis

3.Idd Measuring

4. Powered leakage test

4、 Emmi: write down the power on mode, voltage and current of the sample, whether it is a bare die, whether it has been opened, special requirements, etc. Emmi is a power on test, which can connect various source meters to confirm the power on requirements. If the laboratory does not have a suitable source meter, it can be brought by itself to avoid useless work.

1. Leakage of p-n interface; P-n interface collapse

2. Hot electron of saturation region transistor

3. Photon excitation caused by oxide leakage current

4.Latch up、Gate Oxide Defect、Junction Leakage、

Hot carriers effect, ESD and other problems

5、 FIB: write down whether the sample size, material and conductivity are good. If the size is large, it needs to be cut in advance. Generally, the sample table is about 1-3cm, too large samples can not be put in, and image positioning is also required. Samples with good conductivity can be analyzed faster, and samples with poor conductivity need auxiliary measures to be analyzed better. For tangent point observation, the requirements of tangent point shall be clearly marked. Write a plan for tangent connection and send positioning documents.

1. Chip circuit modification and layout verification

2. Cross section analysis

3.Probing Pad

4. Fixed point cutting

6、 SEM: write down whether the sample size, material and conductivity are good. If the size is large, it needs to be cut in advance. Generally, the sample table is about 1-3cm, too large samples can not be put in, and image positioning is also required. Samples with good conductivity can be analyzed faster, and samples with poor conductivity need auxiliary measures to be analyzed better.

1. Material surface morphology analysis and micro area morphology observation

2. Analysis of material shape, size, surface, section and particle size distribution

3. Surface morphology observation, film roughness and film thickness analysis of film samples

4. Nano size measurement and marking

7、 EDX: write down the sample size and material. EDX is a qualitative analysis, which can see the material and approximate proportion of the sample, which is suitable for metal element analysis.

1. Qualitative analysis of micro component

8、 Probe: write down the requirements of the sample test environment, what source table to match and what probe to use. Generally, there are hard needle and soft needle. The soft needle is thin, which is not easy to cause secondary damage to the sample.

1. Small connection point signal leading out

2. Failure analysis and failure confirmation

3. Confirmation of electrical characteristics after modification of FIB circuit

4. Wafer reliability verification

9、 Om: write down the sample and the requirements for magnification. Om belongs to surface observation and cannot see the internal situation.

1. Sample appearance and morphology inspection

2. Metallographic and microscopic analysis of prepared samples

3. Search for various defects

4. Transistor spot welding and inspection

10、 RIE: write down the sample material and the area to be seen.

1. For isotropic and anisotropic etching of materials using fluorine based chemistry, including carbon, epoxy resin, graphite, indium, molybdenum, nitrogen oxide, photoresist, polyimide, quartz, silicon, oxide, nitride, tantalum, tantalum nitride, titanium nitride, tungsten titanium and tungsten

2. Etching of device surface pattern.