1. A prepreg comprising:
a fibrous substrate; and
a resin composition with which the substrate is impregnated, and which is heated and dried,
wherein a resin flow of the prepreg measured under conditions of 170\xb0 C. and 30 kgfcm2 according to IEC 60249-3-1, 1981, is 0% or more and 5% or less, and
in a dynamic viscoelasticity test under conditions of a temperature of 30\xb0 C. or higher and 200\xb0 C. or lower, a temperature rising rate of 3\xb0 C.min, and a frequency of 0.5 Hz, a relation of 1\u2266VbVa\u226615 is established, where Va is a minimum melt viscosity of the resin composition collected from the prepreg, Vb is a melt viscosity of the collected resin composition at a temperature Tb, Tb=Ta+20\xb0 C., and Ta is a temperature when the melt viscosity is the minimum melt viscosity Va.
2. The prepreg according claim 1,
wherein a gel time, of the resin composition collected from the prepreg, measured according to IEC 60249-3-1, 1981, at 200\xb0 C. is 90 seconds or longer and 360 seconds or shorter.
3. The prepreg according claim 1,
wherein the resin composition includes
a polymer having a glass transition temperature of 100\xb0 C. or lower and a weight average molecular weight of 10,000 or more and 1,000,000 or less,
an epoxy resin curing agent having a phenolic hydroxyl group equivalent of 400 geq or more and 1,000 geq or less,
an epoxy resin having two or more epoxy groups in one molecule, and
an inorganic filler.
4. The prepreg according claim 3,
wherein the polymer has repeating units expressed by following structural formulae (I) and (II), and an epoxy group:
where a relation of 0\u2266x(x+y)\u22660.35 is established, R1 represents H or CH3, and R2 represents H or an alkyl group, in the formulae (I) and (II).
5. The prepreg according claim 3,
wherein the epoxy resin curing agent is a polyphenylene ether copolymer having a number average molecular weight of 500 or more and 2,000 or less.
6. The prepreg according claim 3,
wherein the epoxy resin curing agent is a polyphenylene ether copolymer having an average number of phenolic hydroxyl groups of 1.5 or more and 3 or less at a molecule terminal in one molecule.
7. The prepreg according claim 3,
wherein the epoxy resin curing agent includes 2,6-dimethylphenol and at least one of a bifunctional phenol and a trifunctional phenol.
8. A metal-clad laminate comprising:
an insulting layer that is a cure product of the prepreg as defined in claim 1; and
a metal foil laminated on the insulating layer.
9. A printed wiring board comprising:
an insulting layer that is a cure product of the prepreg as defined in claim 1; and
a conductor pattern formed on the insulting layer.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. A method for processing data from a scanning electron beam apparatus, the method comprising:
scanning an area of a specimen with an electron beam;
storing detected pixel intensity data from the scan into a separate one of multiple frame buffers;
repeating the scanning and the storing; and
image analysis of the pixel intensity data as a function of a frame number, which designates one of the multiple frames in the frame buffer.
2. The method of claim 1, wherein the image analysis includes projecting the pixel intensity data to calculate pixel intensities at a hypothetical frame number zero so as to generate a pixel intercept image therefrom.
3. The method of claim 1, wherein the image analysis includes determining a rate of change of pixel intensity per successive frame so as to generate a pixel slope image therefrom.
4. A method for processing image data from a scanning electron beam apparatus, the method comprising:
processing the image data as a function of pixel position with a filter function having a series of filter strengths; and
measuring a critical dimension (CD) in the processed image data at each filter strength.
5. The method of claim 4, further comprising generating a critical dimension curve as a function of filter strength.
6. The method of claim 5, wherein the critical dimension curve includes a split therein into two curves.
7. The method of claim 6, wherein a first curve tracks a main edge measurement of the CD, and a second curve tracks a \u201cfooting included\u201d measurement of the CD.
8. The method of claim 6, wherein a first curve tracks a dominant aspect of a feature of interest and a second curve tracks a combined aspect of the feature of interest.
9. The method of claim 8, wherein the feature of interest comprises a line formed on a semiconductor substrate, the dominant aspect comprises a main edge of the line, and the combined aspect comprises the main edge plus a shoulder of the line.
10. The method of claim 8, wherein the feature of interest comprises a hole formed on a semiconductor substrate, the dominant aspect comprises a main edge of the hole, and the combined aspect comprises the main edge plus footings in the hole.
11. A scanning electron beam apparatus, the apparatus comprising:
an electron beam column configured to generate a primary electron beam;
a scanning system configured to scan the electron beam over an area of a specimen;
a detection system coordinated with the scanning system and configured to generate pixel data from each scan;
circuitry configured to store detected pixel data from each scan into one of the multiple frame buffers; and
a multi-frame data processor coupled to the multiple frame buffers and configured to analyze the pixel data as a function of frame number.
12. The apparatus of claim 11, wherein the analysis projects the pixel data to calculate pixel values at a frame number zero and generates a pixel intercept image from the calculated pixel values.
13. The apparatus of claim 11, wherein the analysis includes calculating a rate of change in pixel value per successive frame and generates a pixel slope image from the calculated rate of change in pixel value.
14. A scanning electron beam apparatus, the apparatus comprising:
an electron beam column configured to generate a primary electron beam;
a scanning system configured to scan the electron beam over an area of a specimen;
a detection system coordinated with the scanning system and configured to generate pixel data from each scan; and
a data processor coupled to the detection system,
wherein the data processor is configured to process the image data as a function of pixel position with a filter function having a series of filter strengths, and to measure a critical dimension in the processed image data at each filter strength.
15. The apparatus of claim 14, wherein the data processor is further configured to generate a critical dimension curve as a function of filter strength.
16. The apparatus of claim 15, wherein the critical dimension curve includes a split therein into two curves.
17. The apparatus of claim 16, wherein a first curve tracks a main edge measurement of the critical dimension, and a second curve tracks a \u201cfooting included\u201d measurement of the critical dimension.
18. The apparatus of claim 16, wherein a first curve tracks a dominant aspect of the critical dimension and a second curve tracks a combined aspect of the critical dimension.