Plasma polyimides

MPa and 380°C, was partially carbonized and brittle. This carbonization is thought to be due to the plasma. Polyimide is heat-resistant over 400°C, and cannot be carbonized at that temperature. 

Fig. 4. Examples of emission spectrometry as a diagnostic monitoring tool for plasma processing, (a) The removal of chlorine contamination from copper diode leads using a hydrogen—nitrogen plasma. Emissions are added together from several wavelengths, (b) The etching and eventual removal of a 50-p.m thick polyimide layer from an aluminum substrate, where (x ) and (° ) correspond to wavelengths (519.82 and 561.02 nm, respectively) for molecular CO2...

Exposure of the polyimide to an oxygen plasma for times as short as I s... 

After deposition of 0.5 nm of copper onto plasma modified polyimide, the peaks due to carbon atoms C8 and C9 and the oxygen atoms 03 and 04 were reduced in intensity, indicating that new states formed by the plasma treatment were involved in formation of copper-polyimide bonds instead of the remaining intact carbonyl groups. Fig. 28 shows the proposed reaction mechanism between copper and polyimide after mild plasma treatment. 

Fig. 28. Proposed mechanism for reaction of copper with PMDA/ODA polyimide that was treated in an oxygen plasma for 1 s. Reproduced by permission of John Wiley and Sons from Ref. [33].

Negative TOF-SIMS speetra of PMDA/ODA polyimide before and after plasma treatment are shown in Fig. 53. The speetra generally show inereas-ing fragmentation as a function of plasma treatment time. This tendency was especially evident for the peak at m/z = 215 (PMDA + H ). 

After metallization of the plasma-modified polyimide, there were a number of peaks in the TOF-SIMS spectra that confirmed the existence of Cu-N bonds as required by the proposed reaction mechanism (see Fig. 28). The most significant... 

While polymeric surfaces with relatively high surface energies (e.g. polyimides, ABS, polycarbonate, polyamides) can be adhered to readily without surface treatment, low surface energy polymers such as olefins, silicones, and fluoropolymers require surface treatments to increase the surface energy. Various oxidation techniques (such as flame, corona, plasma treatment, or chromic acid etching) allow strong bonds to be obtained to such polymers. 

The 02 reactive ion etching rates of poly(disilanylenephenylene) 10 and 11, and polyimide (PIQ) were measured. As can be seen in Figure 4, the polymers 10 and 11 show very high etching resistance against the oxygen plasma, compared with the PIQ. 

Plasma-deposited fluorocarbon polymers or vacuum-deposited Teflon, polyimide, or parylene... 

As stated, the capability of plasma deposits to reduce the access of water to corrosion-sensitive surfaces may be an important motivation for their application in corrosion protection. In order to study this property, Kapton polyimide film was selected as the substrate because of its high inherent permeability to water and its ability to resist elevated temperatures. The response of Kapton film overcoated by PPHMDSO to the permeation of water vapor is shown in Fig. 1. Clearly, the presence of the organo-silicone plasma film greatly reduces water permeation. The magnitude of the effect is much enhanced when plasma polymers are produced at high T and p. 

Three different dry etch techniques were investigated isotropic O2 plasma etching in a Tegal 200 reactor, R.I.E. in a parallel-plate in-house modified Tegal AOO reactor and R.I.M. in a Veeco, Model RG-830. The conditions of operation for each system were as follows where time is the time to etch 1.2 p of fully cured polyimide. 

Experiments like those described above have been performed to evaluate sodium ion barrier properties of Hitachi PIQ and DuPont PI 2540 polyimide films. Also included in the comparison were silicon nitride coatings plasma deposited in both tensile and compressive stress modes. The structure of the samples is illustrated in Figure 9. N-type, (111) oriented silicon substrates were cleaned and oxidized in dry oxygen ambient at 1100°C to form a 1060 A Si02 film. Wafers intended for polyimide characterization were coated with an organic silane film (gamma glycidal amino propyl trimethoxysilane) to promote adhesion of the polyimide to the oxide surface. The polyimide resins were spun onto the wafers at speeds to produce final... 

Research Focus Synthesis of polyaromatic ether polyimides as adhesives by plasma or thermal treatment of the film surface. 

Flexible copper-clad laminates with nonthermoplastic polyimides were prepared in a two-step process entailing isolating the polyamic acid and then thermally imidizing to the corresponding polyimide. Plasma or thermal treatments of selected polyimides generated materials with excellent bonding strength when evaluated on laminated copper foil. 

TABLE 2. Bonding Strength of Selected Thermoplastic Polyimides after Exposing Surfaces to Plasma Treatment or Heating Material to 380°C... 

---