I think something is off. Sun IPO'd in 1986. The first SparcStation wasn't released until 1989. I can't find any evidence they ever declared bankruptcy of any sort...
Yes, the SPARC processor went under development in 1984ish, IPO in 1986, market "correction worst since 1928" in 1987, but SPARCstation 1, the first commercial system with SPARC, was not released until 1989 and SUN drifted sideways because of the difficult transition to RISC (and System V?) from CISC (and BSD4.2) until the Internet taking-off (due to Vincent Cerf releasing async-PPP as Microsoft RAS) generated massive server demand beginning around 1996 (followed by dot-com bubble, crash, nuclear winter, rise of free software particularly LINUX and ultimately death of SUN). Drifting sideways after 1989 on the remains of DEC's high-end business (with DEC's low-end aka "departmental" business going to the PC's running Windows NT "server") was preferable to what happened to virtually every other major computer manufacturer of that era (including IBM --those monsters simply laid off hundreds of thousands of Americans, sold off their PC assets to ChYna and opened massive plants in Bangalore to write code in SUN's Java set-top-box language).
The Sun 4/260 workstation and 4/280 server were introduced in 1987. I did a truly trivial port of a complex AI framework to it at that time. The lower priced 4/110 was introduced in early 1988 (I bought one at the huge Sun auction post SS1 introduction).
The first shipping SPARC implementation was Fujitsu’s MB86900 from 1986, which was used at 16.67 (260) and 14Mhz (110).
Solaris / System V was definitely a difficult transition for them. Early versions of Solaris 2.x were pretty bad. They had to maintain SunOS 4.x well into the 90's. I think it was finally obsolete in 1995 when the new Ultra line wouldn't run it.