Mitsubishi Denki Kabushiki Kaisha

Ryoden Semiconductor System Engineering Corporation

Yoshirou Nishinaka

Shunichi Abe

Naoto Ueda

Yoshihiro Tomita

Hideyuki Ichiyama

Toshio Takeuchi

Katsuyuki Fukutome

Yoshihiro Kashiba

Goro Izuta

Seizou Ohumae

Katunori Asai

Masaaki Namatame

A leadframe for producing a semiconductor device having a lead-on chip (LOC) structure with leads extending across a semiconductor chip, the leadframe includes a frame for a die pad having an outer frame section, a die pad displaced from the outer frame section, and a suspending lead connecting the die pad to the outer frame section with the die pad disposed inside the outer frame section; and a frame for leads including an outer frame portion and leads extending from opposite sides of the outer frame portion, connected to the frame for a die pad, the die pad being connected to the frame for leads at the suspending lead, wherein one of the frame for a die pad and the frame for leads includes a projection and the other of the frame for a die pad and the frame for leads includes a hole, the hole receiving the projection, the projection being disposed parallel to the frame for leads, connecting the frame for a die pad to the frame for leads.

Lead frame including frame-cutting slit for lead-on-chip (LOC)

A high-reliability semiconductor device and a method of producing the device. Absorption of moisture into a semiconductor device is effectively avoided by using a hard solder material, such as common solder having no moisture absorption, for die-bonding a semiconductor chip to a die pad. Thus, in the semiconductor device in accordance with the present inventions there are no corrosion problems nor package-cracking due to absorbed moisture.

Leadframe including frame-cutting slit for lead-on-chip (LOC)

A method of making a semiconductor device having a lead-on-chip structure includes bending a die pad extending from an outer frame outwardly from the outer frame. Thereafter, with the die pad in a convenient position, a semiconductor chip is die-bonded to the die pad. Thereafter, the die pad is bent back toward the outer frame so that it is generally parallel to but spaced from the outer frame with leads extending from the outer frame being generally parallel to the semiconductor chip. Electrodes of the semiconductor chip are connected by wire-bonding to the leads extending from the outer frame. After resin molding, the outer frame lying outside the resin package is severed and removed, completing the lead-on-chip semiconductor device.

Method of making leadframe for lead-on-chip (LOC) semiconductor device

A solder material comprises a first solder plate and a second solder plate having a thickness equal to or larger than 1 micron provided at the both surfaces of the first solder plate comprising material-having a lower melting point than the first solder or material which reacts with the first solder to produce an alloy having a lower melting point than the first solder. A junctioning method comprise putting the above-described solder material inserted between two objects to be junctioned to each other; heating the solder material to a temperature higher than the melting point of the second solder or the alloy and lower than the melting point of said first solder thereby to melt the second solder or the alloy; and thereafter cooling or keeping the solder material at a temperature in the vicinity of the melting point thereby to junction the objects to be junctioned to each other. The second solder plate has preferably a thickness less than 5 microns and the first solder plate has preferably a thickness equal to or larger than 30 microns. By this construction, the interval between the objects to be junctioned can be controlled to a predetermined thickness and the stress functioning to the objects can be relaxed as well as there arises no positional deviation between the objects.

Solder material, junctioning method, junction material, and

A semiconductor device including a lead on chip structure employs two frames. One of the frames includes a die pad and an outer frame portion and the other frame includes a plurality of leads and an outer lead portion. After a semiconductor chip is die bonded to the die pad, the two frames are connected to each other with the leads extending across the semiconductor chip. Slits within the second frame provide access to parts of the outer frame of the first frame and the first frame is severed at those slits. The severed portions of the first frame are removed after which the leads of the second frame are connected by wire bonding to the semiconductor chip. Finally, the semiconductor chip, the remaining part of the first frame, and the second frame are encapsulated in a resin with leads extending from the resin. The remaining parts of the outer frame of the second frame are removed by cutting and the exposed leads outside the resin are formed into a desired shape.

Method of making a lead on chip (LOC) semiconductor device

A solder material comprises a first solder plate and a second solder plate having a thickness equal to or larger than 1 micron provided at the both surfaces of the first solder plate comprising material having a lower melting point than the first solder or material which reacts with the first solder to produce an alloy having a lower melting point than the first solder. A junctioning method comprises putting the above-described solder material inserted between two objects to be junctioned to each other; heating the solder material to a temperature higher than the melting point of the second solder or the alloy and lower than the melting point of said first solder thereby to melt the second solder or the alloy; and thereafter cooling or keeping the solder material at a temperature in the vicinity of the melting point thereby to junction the objects to be junctioned to each other. The second solder plate has preferably a thickness less than 5 microns and the first solder plate has preferably a thickness equal to or larger than 30 microns. By this construction, the interval between the objects to be junctioned can be controlled to a predetermined thickness and the stress functioning to the objects can be relaxed as well as there arises no positional deviation between the objects.

Growing community of inventors

Itami, Japan

Yoshirou Nishinaka