BS EN 60749-39-2006 Semiconductor devices - Mechanical and climatic test methods - Measurement of moisture diffusivity and water solubility in organic materials used for semiconduc.pdf

1、 g49g50g3g38g50g51g60g44g49g42g3g58g44g55g43g50g56g55g3g37g54g44g3g51g40g53g48g44g54g54g44g50g49g3g40g59g38g40g51g55g3g36g54g3g51g40g53g48g44g55g55g40g39g3g37g60g3g38g50g51g60g53g44g42g43g55g3g47g36g58methods Part 39: Measurement of moisture diffusivity and water solubility in organic materials used

2、 for semiconductor componentsThe European Standard EN 60749-39:2006 has the status of a British StandardICS 31.080.01Semiconductor devices Mechanical and climatic test BRITISH STANDARDBS EN 60749-39:2006BS EN 60749-39:2006This British Standard was published under the authority of the Standards Polic

3、y and Strategy Committee on 29 December 2006 BSI 2006ISBN 0 580 49866 2Amendments issued since publicationAmd. No. Date Commentssecretary.This publication does not purport to include all the necessary provisions of a contract. Users are responsible for its correct application.Compliance with a Briti

4、sh Standard cannot confer immunity from legal obligations.National forewordThis British Standard was published by BSI. It is the UK implementation of EN 60749-39:2006. It is identical with IEC 60749-39:2006. It partially supersedes BS EN 60749:1999 which will be withdrawn when the last part in the s

5、eries is published. The UK participation in its preparation was entrusted to Technical Committee EPL/47, Semiconductors.A list of organizations represented on EPL/47 can be obtained on request to its EUROPEAN STANDARD EN 60749-39 NORME EUROPENNE EUROPISCHE NORM August 2006 CENELEC European Committee

6、 for Electrotechnical Standardization Comit Europen de Normalisation Electrotechnique Europisches Komitee fr Elektrotechnische Normung Central Secretariat: rue de Stassart 35, B - 1050 Brussels 2006 CENELEC - All rights of exploitation in any form and by any means reserved worldwide for CENELEC memb

7、ers. Ref. No. EN 60749-39:2006 E ICS 31.080.01 English version Semiconductor devices - Mechanical and climatic test methods Part 39: Measurement of moisture diffusivity and water solubility in organic materials used for semiconductor components (IEC 60749-39:2006) Dispositifs semiconducteurs - Mthod

8、es dessais mcaniques et climatiques Partie 39: Mesure de la diffusion dhumidit et de lhydrosolubilit dans les matriaux organiques utiliss dans les composants semiconducteurs (CEI 60749-39:2006) Halbleiterbauelemente - Mechanische und klimatische Prfverfahren Teil 39: Messung des Feuchtediffusionskoe

9、ffizienten und der Wasserlslichkeit in organischen Werkstoffen, welche bei Halbleiter-Komponenten verwendet werden (IEC 60749-39:2006) This European Standard was approved by CENELEC on 2006-08-01. CENELEC members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the condi

10、tions for giving this European Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references concerning such national standards may be obtained on application to the Central Secretariat or to any CENELEC member. This European Standard exists in th

11、ree official versions (English, French, German). A version in any other language made by translation under the responsibility of a CENELEC member into its own language and notified to the Central Secretariat has the same status as the official versions. CENELEC members are the national electrotechni

12、cal committees of Austria, Belgium, Cyprus, the Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, the Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and the Unite

13、d Kingdom. Foreword The text of document 47/1860/FDIS, future edition 1 of IEC 60749-39, prepared by IEC TC 47, Semiconductor devices, was submitted to the IEC-CENELEC parallel vote and was approved by CENELEC as EN 60749-39 on 2006-08-01. The following dates were fixed: latest date by which the EN

14、has to be implemented at national level by publication of an identical national standard or by endorsement (dop) 2007-05-01 latest date by which the national standards conflicting with the EN have to be withdrawn (dow) 2009-08-01 _ Endorsement notice The text of the International Standard IEC 60749-

15、39:2006 was approved by CENELEC as a European Standard without any modification. _ EN 60749-39:2006 2 CONTENTS 1 Scope 4 2 Apparatus.4 3 Samples.4 4 Procedure 5 4.1 Sample preparation .5 4.2 Absorption measurements below 100 C 5 4.3 Solubility and diffusivity calculation 7 4.4 Desorption measurement

16、s above 100 C7 5 Calculation of activation energy for moisture diffusion 8 6 Summary .9 Figure 1 Example of linearly increasing mass gain6 EN 60749-39:2006 3 SEMICONDUCTOR DEVICES MECHANICAL AND CLIMATIC TEST METHODS Part 39: Measurement of moisture diffusivity and water solubility in organic materi

17、als used for semiconductor components 1 Scope This part of IEC 60749 details the procedures for the measurement of the characteristic properties of moisture diffusivity and water solubility in organic materials used in the packaging of semiconductor components. These two material properties are impo

18、rtant parameters for the effective reliability performance of plastic packaged semiconductors after exposure to moisture and being subjected to high-temperature solder reflow. NOTE It is recommended that the moisture absorption parameters used in this standard be obtained from the material suppliers

19、 (such as the resin supplier). 2 Apparatus 2.1 Analytical balance capable of a resolution of either 0,000 01 g or 0,001 % of sample mass. 2.2 High-temperature oven capable of maintaining uniform temperatures from 100 C to 250 C 2 C. 2.3 Temperature/humidity chamber(s) capable of maintaining temperat

20、ures in a range from 30 C to 85 C and relative humidities (HR) in a range from 60 % HRto 85 % HR. Within the chamber working area, temperature tolerance shall be 2 C and the HRtolerance shall be 3 % HR. 2.4 Perforated stainless steel trays or stainless steel wire mesh baskets used for holding sample

21、s and for placement into ovens. 2.5 Large aluminium plate or disk used for heat sink capability. 2.6 Desiccator for holding dry samples. 3 Samples Samples must be flat parallel-sided discs or coupons. The linear dimensions shall be accurately measured to within 0,02 mm. To approximate one-dimensiona

22、l diffusion behaviour with edge effects limited to less than 5 % of the total diffusional moisture mass uptake, the free surface area in the thickness dimension must be less than 5 % of the flat-sided free surface area of the sample. For a disc of radius, r, and thickness, h, the following relation

23、shall be met: h 0,05r (1) EN 60749-39:2006 4 for a coupon of length, L, and width, W, )()(0,05LWWLh+= (2) Recommended sample thickness should be in the range from 0,3 mm to 1,0 mm. It is recommended that the maximum sample thickness should not exceed 1,0 mm, because the time to achieve moisture satu

24、ration at temperatures below 60 C will be excessively long for compounds with slow diffusivity. 4 Procedure 4.1 Sample preparation 4.1.1 Process and cure the samples using recommended processing conditions in accordance with the manufacturers specification. 4.1.2 To obtain the appropriate sample thi

25、ckness as given by equations (1) or (2), samples may be sectioned and finely polished from larger specimens. Care must be taken to maintain near parallel-sided flatness for samples prepared in this manner. The prepared samples should be inspected for voids, both internal and surface. The ideal sampl

26、es should be nearly void-free. 4.2 Absorption measurements below 100 C 4.2.1 Measure the linear dimensions of the prepared sample to the nearest 0,02 mm. Record the sample thickness, h, and calculate the sample volume, V, using the appropriate geometric relationship based on the sample shape. 4.2.2

27、Bake the sample at 125 C for 24 h. Longer bake times may be required depending on the sample mass loss characteristics. The sample is considered dry when successive measurements result in less than 0,002 % difference between readings. 4.2.3 Remove the sample from the bake oven and immediately cool b

28、y placing in contact with the heat sink of 2.5. If more than one sample is to be measured, the samples and heat sink should be placed into a desiccator to limit moisture uptake during the mass measurements. 4.2.4 Measure the mass of the sample according to 2.1 and record the mass as MComp,dry,1The m

29、ass gain/loss measurement shall be made within a few minutes after removal of the sample from the environmental chamber. Time delays longer than 5 min after removal from the environmental chambers could affect the resultant diffusivity measurements. EN 60749-39:2006 5 4.2.5 Place the sample into a s

30、tainless steel holder and transfer to a temperature/humidity chamber stabilized at a pre-set temperature and humidity. It is suggested that the sample be transferred into a stainless-steel holder that has been preheated and stabilized to the set chamber temperature. 4.2.6 At accumulative times, remo

31、ve the sample from the temperature/humidity chamber, cool in accordance with 4.2.3 and measure the sample mass. Time intervals should be spaced so as to allow adequate measurement duration to capture the initial quick mass response and to provide a good spread in the data points during the later sta

32、ges of the mass response curve. The total number of times the temperature/humidity chamber is disturbed for sample removal should be minimized. Care should be taken that no condensed moisture from the chamber walls comes into contact with the sample during removal from the temperature/humidity chamb

33、er. If condensed water should contact the sample, immediately dry the sample using nitrogen or dry air. The sample should then be returned to the chamber for re-equilibration and another data point taken at a later time. 4.2.7 Place the sample back into the temperature/humidity chamber and continue

34、mass measurements until either of the following conditions are met. a) Additional weight gain after a 24 h period is less than 0,002 % from the previous measurement. b) A plot of the weight gain verses time shows a linearly increasing weight gain after an initial decreasing change in mass with time

35、(dM/dt), as depicted in Figure 1. dM/dt = constant Time MMoisturemassIEC 1186/06 Figure 1 Example of linearly increasing mass gain 4.2.8 Record the final wet mass of the sample as MComp,wet,f4.2.9 Bake the sample again at 125 C until dry as determined by 4.2.2. 4.2.10 Record the second final dry mas

36、s as MComp,dry,2EN 60749-39:2006 6 4.3 Solubility and diffusivity calculation 4.3.1 Calculate the solubility at the given temperature and humidity by using: VMMHTCdry,2Comp,fComp,wet,Rsat),(= = VHTM ),(Rsat(3) where Csat(T,HR) is the moisture solubility at temperature T and HR(in mg cm3); MComp,wet,

37、fis the final wet sample mass (in mg); MComp,dry,2is the final dry sample mass after the second bake (in mg); V is the sample volume (in cm3); Msat(T,HR) is the saturated moisture content at temperature T and HR(in mg). 4.3.2 Plot mass gain curve verses time using change in mass as M(t) MComp,dry,14

38、.3.3 Using the plotted curve, calculate the moisture diffusivity from 0,5219 049,0)(thTD = (4) where D(T) is the diffusivity at temperature T (in mm2s1); H is the sample thickness (in mm); t0,5 is the sorption half-time defined as the time at which the sorbed mass of moisture is equal to one-half th

39、e saturated mass, for example, Mt/Msat = 0,5; Mtis the mass of moisture at time t. NOTE An alternate method for determining D(T) is to use a best-fit curve-fitting approach of the experimental weight gain data. Equation (4) above is recognized as an approximation to the analytical closed form soluti

40、on, however, it will provide an accurate approximation of an error of less than a few per cent. The value of D(T) determined by a curve-fitting technique should be compared to the value determined by equation (4) as a reference check. Repeat the sorption measurements 4.2 to 4.3.3 using different tem

41、perature and humidity conditions. Suggested environmental conditions are 30 C/60 % HR, 60 C/60 % HR, and 85 C/60 % HR. 4.4 Desorption measurements above 100 C 4.4.1 Place the sample in a chamber maintained at 85 C/60 % HRor 85 C/85 % HRfor 168 h or until Msat is achieved as determined by a calculati

42、on using a previously determined diffusivity at 85 C. 4.4.2 Remove the sample from the temperature/humidity chamber, cool in accordance with 4.2.3 and record the saturated sample weight, Msat. 4.4.3 Immediately place the sample into a bake oven stabilized at a temperature greater than 100 C. It is s

43、uggested that the sample be transferred into a stainless-steel holder that has been preheated and stabilized at the set bake temperature. EN 60749-39:2006 7 4.4.4 Remove the sample after a recorded elapsed period of time, immediately cool in accordance with 4.2.3 and measure the sample weight in acc

44、ordance with 4.2.4. 4.4.5 Repeat steps 4.4.3 and 4.4.4 until the sample is dry. Appropriate times for recording weight losses can be determined by using a first-order extrapolation of the value for the diffusivity by using an Arrhenius fit (see Clause 5) of the absorption diffusivities determined in

45、 4.3.3. Estimated weight losses can be assessed by using the following equation: satt +=222202)12(exp)12(181htDnnMMn(5) where D is the diffusivity; t is the time. 4.4.6 Calculate D(T) using Equation (4), where t0,5is now defined as the time at which the desorbed mass of moisture is equal to one-half

46、 of the saturated mass. 4.4.7 Reset the bake oven to a higher bake temperature and repeat measurements following 4.4.1 to 4.4.6. 5 Calculation of activation energy for moisture diffusion The activation energy for moisture diffusion is calculated from the slope of a plot of lnD(T) versus 1/T where T

47、is in degrees Kelvin. Report the best fit line as: kexp)(a0=TEDTD (6) where D0is the pre-exponential factor for fitted line (in mm2/s); Eais the activation energy (in eV); k is Boltzmans constant, 8,617 105eV/K. NOTE 1 Diffusion of moisture may show a dependency on the glass transition temperature (

48、Tg) of the material. Measurements above the Tgof the material should be reported as a separate activation energy and pre-exponential factor. NOTE 2 For accurate determination of the activation energy, it is recommended that a minimum of three temperatures differing by 20 C to 30 C for both above and

49、 below Tg be used. EN 60749-39:2006 8 6 Summary The following information shall be tabulated. a) Mould compound identification (see Clause 4) b) Test temperature (see Clause 4) c) D0(see Clause 5) d) Ea(see Clause 5) e) Csat(T,HR) (see 4.3.1) f) D(T) (see 4.3.1) _ EN 60749-39:2006 9 BS EN BSI389 Chiswick High RoadLondonW4 4AL60749-39:2006BSI British Standards InstitutionBSI is the independent national body res