Hello, everyone. I’m Sasatani with the package design section of the Tokyo office.

Packing materials for semiconductor products need to be designed to ensure that the products can be properly protected against vibration, shock and compression pressure during transportation, and to be evaluated by performance test. In this article, we will introduce a technique to evaluate whether the packaging materials are properly designed.

 

 

1. Evaluation for possible transportation stress

You first determine the expected level of vibration during transport (Table 1) and perform randomized vibration tests (Table 2) depending on the level.

 

(1) Vibration in transportation packing materials receives

 

Table 1. Expected level of vibration during transportation

	Short distance (≤ 200 km)	Long distance (≥ 2500 km)	Good transportation infrastructure	Poor transportation infrastructure
Domestic transport	Level 3	Level 1	Level 3	–
Overseas transport	–	Level 1	Level 2	Level 1

(Severity: Level 1 > Level 2 > Level 3)

 

Table 2. Conditions for randomized vibration test

Test Time
Level	Level 1	Level 2	Level 3
Time (min.)	180	90	15
Acceleration Power Spectral Density
Frequency	For all levels
Hz	(m/s2)2/Hz	,	(g2/Hz)a)
3	0.048	,	(0.0005)
6	1.15	,	(0.012)
18	1.15	,	(0.012)
40	0.096	,	(0.001)
200	0.048	,	(0.0005)
Effective acceleration value :5.8 m/s2 [0.59 ga)] Note a)  g=9.806 658 m/s2

 

(2) Drop impact at transportation / transshipment

Assume the impact of transshipment to and from trucks, ships, freight cars, or transshipment across carriers during the transportation process.
Then you can determine the drop height of the free fall test from the assumed level and the total package mass. (Table 3)

Level I: When transshipment frequency is high and very large external forces are expected to be applied.

Level Ⅱ: When transshipment frequency is high and relatively large external forces are expected to be applied.

Level III: When transshipment frequency and magnitude of external force applied are expected as normal.

Level IV: When transshipment frequency is low and there is no risk of significant external force.

 

Table 3. Drop height (free fall test)

Total package mass (kg/case)	Drop height (cm)
	Level I	Level II	Level III	Level IV
<10	80	60	40	30
10≤      <20	60	55	35	25
20≤      <30	50	45	30	20
30≤      <40	40	35	25	15
40≤      <50	30	25	20	10
50≤      <100	25	20	15	10

 (Severity: Level Ⅰ > Level Ⅱ > Level Ⅲ > Level Ⅳ)

 

 

2. Packing Boxes Strength Evaluation

To perform a quantitative strength evaluation, determine the conditions of the evaluation test in accordance with JIS Z0212:1998 (Packaged freights and containers — Method of compression test).

For the compression test, apply pressure to the boxes at a constant velocity across the boxes with parallel plates. The boxes under pressure will not crumble until it exceeds their load capacity, but once it exceeds the limit, they lose repulsive force and begin to crumble. Compression testing allows you to observe how the boxes crumble evenly or unevenly, so you can determine if your designed boxes have the desired strength (i.e., load-bearing capacity) from the appearance of the beginning of crumbling and the result of maximum load.

If you have multiple factories producing the same product, the packing box materials and specifications that differ from one manufacturer to another. In case you standardize packing boxes, it is unthinkable to manage materials and specifications that differ from one manufacturer to another.
Since packing boxes materials and specifications vary from region to region and country to country, strength comparisons in compression tests are a useful evaluation method.

A lot of WTI’s experience in packing materials design for semiconductor products and evaluation of them allows us to offer you a suitable packing materials design. If you have any problems with packing materials for semiconductor products, please feel free to contact us.