SolidWorks can generally export its own drawings to eDrawings EASM format, so you can simply import IGS/IGES files to it and export it as EASM. Just keep in mind eDrawings are used for viewing and previewing purposes only and cannot be further edited by CAD programs.
Convert IGES 3D exchange format to SolidWorks eDrawing assembly data.
We have found one software suitable in our database for this conversion.
Microsoft Windows software - convert igs to easm on Windows
A 2D and 3D CAD construction software
Convert from igs file format
The table with program actions contains information about what each program is capable of doing with their files. This may be a good pointer for further searches for certain file conversions and help you find the converter you are looking for if our search result is insufficient for you. However, it is far from perfect and may sometimes show results which are not really usable because of the nature of the software handles the files. So a conversion that appears as possible, just because of matched actions, may in fact not be possible.