Flip-Chip modules were used in the DEC

Digital Equipment Corporation

Digital Equipment Corporation was a major American company in the computer industry and a leading vendor of computer systems, software and peripherals from the 1960s to the 1990s...

 PDP-7

PDP-7

The DEC PDP-7 is a minicomputer produced by Digital Equipment Corporation. Introduced in 1965, it was the first to use their Flip-Chip technology. With a cost of only $72,000 USD, it was cheap but powerful by the standards of the time. The PDP-7 was the third of Digital's 18-bit machines, with...

 (referred to in documentation as the "FLIP CHIP"), PDP-8

PDP-8

The 12-bit PDP-8 was the first successful commercial minicomputer, produced by Digital Equipment Corporation in the 1960s. DEC introduced it on 22 March 1965, and sold more than 50,000 systems, the most of any computer up to that date. It was the first widely sold computer in the DEC PDP series of...

, PDP-9 and PDP-10

PDP-10

The PDP-10 was a mainframe computer family manufactured by Digital Equipment Corporation from the late 1960s on; the name stands for "Programmed Data Processor model 10". The first model was delivered in 1966...

, beginning on August 24, 1964. The trademark "Flip-Chip"' was filed on August 27, 1964.

There appeared to be some confusion inside DEC at the time, as various manuals refer to it as "FLIP CHIP", "Flip Chip", "FLIP-CHIP", and "Flip-Chip", with trademark and registered trademark symbols.

The modules were called Flip-Chip because early versions of some of these modules used flip chip

Flip chip

Flip chip, also known as Controlled Collapse Chip Connection or its acronym, C4, is a method for interconnecting semiconductor devices, such as IC chips and Microelectromechanical systems , to external circuitry with solder bumps that have been deposited onto the chip pads...

 mounting for individual diode

Diode

In electronics, a diode is a type of two-terminal electronic component with a nonlinear current–voltage characteristic. A semiconductor diode, the most common type today, is a crystalline piece of semiconductor material connected to two electrical terminals...

 chips, but these were eventually found to be unreliable so conventional discrete diodes replaced the flip chips. In later computers where DEC used integrated circuit

Integrated circuit

An integrated circuit or monolithic integrated circuit is an electronic circuit manufactured by the patterned diffusion of trace elements into the surface of a thin substrate of semiconductor material...

s, they continued to use "Flip-Chip" despite the fact that actual flip chip mounting was not used, so that they could retain their trademark

Trademark

A trademark, trade mark, or trade-mark is a distinctive sign or indicator used by an individual, business organization, or other legal entity to identify that the products or services to consumers with which the trademark appears originate from a unique source, and to distinguish its products or...

. Eventually, on June 6, 1987, the trademark was allowed to expire.