Peel strength heat treatment

Peel strength was also affected by the heat treatment steps between metal deposition. The effect on adhesion of the bake time after electrolytic copper deposition is shown in Figure 11. Peel strength as high as 250 g/mm were observed on copper plated ULTEM 2312 with extended heatings at 110°C. Without a heat treatment, peel strength values were 50 g/mm. 

Figure 11. Effect of heat treatment on peel strength...

The relative distribution of the mechanical and chemical components of adhesion were assessed via cathodic chargingl. In this approach, the electrolessly-metallized specimen was employed as the cathode in an electrochemical cell containing a sulfuric acid/arsenic trioxide electrolyte. The adhesion component values were gleaned from peel strength/coulomb curves before and after the final heat treatment. 

Table HI. Effect of Post-Electrolytic Heat Treatment Environment on the Peel Strength of Copper to Polyetherimide. ...

The copper (200 nm) was deposited by evaporation. The temperature was 110°C and the heat treatment time 2 hours. The Ar/Air datum was measured on the Ar sample after an additional 2 hours at 110 C in an air environment. No improvement in peel strength was detected when the sample was heated for an additional 2 hours in Ar. 

Table V. Effect of Heat Treatment Atmosphere on the Peel Strength of Electrolessly-deposited Copper to Polyetherimide Film.

Sample Post- Electroless Heat Treatment (1 hat 110 C) Post- Electrolytic Heat Treatment (2 hat 110"C) Peel Strength (g/mm)... 

Metal Deposition Technique Heat Treatment Time (h) Copper Oxide Thickness (nm) Peel Strength (g/inm)... 

P/HT sample was patterned prior to the heat treatment step. The HT/P specimen was heat treated for 5 hours and then patterned. The HT/P/HT sample was heat treated, patterned, the peel strength assessed, and then heat treated for an additional 5 hours. 

The effect of heat-treatment time on adhesion and the impact of the metal trace width and filler content of the polymer is displayed in Table XI. The data show that for the lightly-filled polymers (20 and 30 % glass loading) that the peel strengths reached their ultimate values irrespective of line width within O.S hours. In contrast when the filler content was SO %, the O.S mm wide line approximated its final value within 0.5 hours while the 3.9 mm trace achieved only 53 % of its maximum value. A total heat-treatment time of 12.S hours was required in order to obtain the final peel strength for the 3.9 mm line and SO % glass loading sample. 

Table XI. Peel Strength of Copper to Glass-Filled Polyetherimide as a Function of Line Width and Heat-Treatment Hme.

Post-Electroless Copper Heat Treatment Peel Strength (g/mm)... 

The polyetherimide was treated according to the Standard 2312 process. Following the post-electroless heat-treatment step, the copper thickness was electrolytically increased, 3.2 mm wide traces created and a final heat treatment at 110°C performed for 16 hours. The peel strength vi as evaluated subsequent to this step. 

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