PFATSDR

Bulk Data Entry Defines properties for solder fatigue analysis.

Format

(1) (2) (3) (4) (5) (6) (7) (8) (9) (10)
PFATSDR ID C4GAMMA K1 K2 K3 K4      

Definition

Field Contents SI Unit Example
ID Entry identification number.

Each PFATSDR entry must have a unique ID. This is referenced by the FATDEF Subcase Information Entry.

No default (Integer > 0)

 
C4GAMMA Empirical model constraint for solder fatigue.

No default (Real > 0)

 
K1 Constant in crack initiation equation in Darveaux method. 2

No default (Real)

 
K2 Constant in crack initiation equation in Darveaux method.

No default (Real)

 
K3 Constant in crack growth equation in Darveaux method. 2

No default (Real)

 
K4 Constant in crack growth equation in Darveaux method.

No default (Real)

 

Comments

  1. C4GAMMA is used to calculate the strain range of the solder joint in DIFFCTE method:(1)
    Δ γ = C L D h s Δ α Δ T MathType@MTEF@5@5@+= feaahqart1ev3aqatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq=Jc9 vqaqpepm0xbba9pwe9Q8fs0=yqaqpepae9pg0FirpepeKkFr0xfr=x fr=xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaGaeyiLdqKaeq 4SdCMaeyypa0Jaam4qamaalaaabaGaamitamaaBaaaleaacaWGebaa beaaaOqaaiaadIgadaWgaaWcbaGaam4CaaqabaaaaOGaeyiLdqKaeq ySdeMaeyiLdqKaamivaaaa@4411@
    Where,
    L D MathType@MTEF@5@5@+= feaahqart1ev3aqatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq=Jc9 vqaqpepm0xbba9pwe9Q8fs0=yqaqpepae9pg0FirpepeKkFr0xfr=x fr=xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaGaamitamaaBa aaleaacaWGebaabeaaaaa@37BA@
    Component length.
    α MathType@MTEF@5@5@+= feaahqart1ev3aqatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq=Jc9 vqaqpepm0xbba9pwe9Q8fs0=yqaqpepae9pg0FirpepeKkFr0xfr=x fr=xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaGaeqySdegaaa@3793@
    Coefficient of thermal expansion (CTE).
    h s MathType@MTEF@5@5@+= feaahqart1ev3aqatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq=Jc9 vqaqpepm0xbba9pwe9Q8fs0=yqaqpepae9pg0FirpepeKkFr0xfr=x fr=xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaGaamiAamaaBa aaleaacaWGZbaabeaaaaa@3805@
    Solder joint height.
    Δ α = C T E p C T E c MathType@MTEF@5@5@+= feaahqart1ev3aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq=Jc9 vqaqpepm0xbba9pwe9Q8fs0=yqaqpepae9pg0FirpepeKkFr0xfr=x fr=xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaGaeyiLdqKaeq ySdeMaeyypa0Jaam4qaiaadsfacaWGfbWaaSbaaSqaaiaadchaaeqa aOGaeyOeI0Iaam4qaiaadsfacaWGfbWaaSbaaSqaaiaadogaaeqaaa aa@4201@
    Difference between thermal expansion coefficients of the PCB and the component soldered onto the board.
    T MathType@MTEF@5@5@+= feaahqart1ev3aqatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq=Jc9 vqaqpepm0xbba9pwe9Q8fs0=yqaqpepae9pg0FirpepeKkFr0xfr=x fr=xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaGaamivaaaa@36CD@
    Input temperature.
    Δ T = T p T c MathType@MTEF@5@5@+= feaahqart1ev3aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq=Jc9 vqaqpepm0xbba9pwe9Q8fs0=yqaqpepae9pg0FirpepeKkFr0xfr=x fr=xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaGaeyiLdqKaam ivaiabg2da9iaadsfadaWgaaWcbaGaamiCaaqabaGccqGHsislcaWG ubWaaSbaaSqaaiaadogaaeqaaaaa@3E17@
    Difference between temperatures of the PCB and the component soldered onto the board.
    C MathType@MTEF@5@5@+= feaahqart1ev3aqatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq=Jc9 vqaqpepm0xbba9pwe9Q8fs0=yqaqpepae9pg0FirpepeKkFr0xfr=x fr=xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaGaam4qaaaa@36BC@
    Empirical model constant for solder fatigue (specified using the C4GAMMA field). It is equal to 1 2 MathType@MTEF@5@5@+= feaahqart1ev3aqatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq=Jc9 vqaqpepm0xbba9pwe9Q8fs0=yqaqpepae9pg0FirpepeKkFr0xfr=x fr=xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaWaaSaaaeaaca aIXaaabaWaaOaaaeaacaaIYaaaleqaaaaaaaa@3796@ for leadless joint type. For BGA type, you can define the empirical model constant.

    Refer to Solder Fatigue Analysis for additional information.

  2. K1 and K3 are dependent on the modeling of solder joints such as the thickness of solder joint interface layers and the creep constitutive model. Therefore, K1 and K3 are not material constants. Units of dimension for K1 and K3 should be consistent with those of length and stress on FATPARM. Dimension of K1 is cycles/stressK2. The dimension of K3 is (length/cycle)*(1/stressK4). For example, if length units and stress units in FATPARM are mm and MPa respectively, the units of K1 and K3 should be cycles/MPaK2 and (mm/cycle)*(1/MPaK4), respectively.
    The constants are used in the following equations to calculate life (N) of a solder joint:
    • Crack initiation:(2)
      N 0 = K 1 Δ W a v e K 2 MathType@MTEF@5@5@+= feaahqart1ev3aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq=Jc9 vqaqpepm0xbba9pwe9Q8fs0=yqaqpepae9pg0FirpepeKkFr0xfr=x fr=xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaGaamOtamaaBa aaleaacaaIWaaabeaakiaaysW7cqGH9aqpcaaMe8Uaam4samaaBaaa leaacaaIXaaabeaakiaabs5acaWGxbWaa0baaSqaaiaadggacaWG2b GaamyzaaqaaiaadUeadaWgaaadbaGaaGOmaaqabaaaaaaa@443E@
    • Crack growth:(3)
      da dN = K 3 Δ W ave K 4 MathType@MTEF@5@5@+= feaahqart1ev3aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq=Jc9 vqaqpepm0xbba9pwe9Q8fs0=yqaqpepae9pg0FirpepeKkFr0xfr=x fr=xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaWaaSaaaeaaca WGKbGaamyyaaqaaiaadsgacaWGobaaaiaaysW7cqGH9aqpcaaMe8Ua am4samaaBaaaleaacaaIZaaabeaakiaabs5acaWGxbWaa0baaSqaai aadggacaWG2bGaamyzaaqaaiaadUeadaWgaaadbaGaaGinaaqabaaa aaaa@461A@
    • Life:(4)
      N = N 0 + a d a d N MathType@MTEF@5@5@+= feaahqart1ev3aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq=Jc9 vqaqpepm0xbba9pwe9Q8fs0=yqaqpepae9pg0FirpepeKkFr0xfr=x fr=xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaGaamOtaiaays W7cqGH9aqpcaaMe8UaamOtamaaBaaaleaacaaIWaaabeaakiaaysW7 cqGHRaWkcaaMe8+aaSaaaeaacaWGHbaabaWaaSGaaeaacaWGKbGaam yyaaqaaiaadsgacaWGobaaaaaaaaa@4538@

    Where, α is the joint diameter at the interface defined FATSDR.