JPH0319262A - Mounting structure of semiconductor device - Google Patents

Abstract

PURPOSE:To prevent the bending and the imperfect contact of a lead and improve the yield by connecting a clad wire between an electrode on a board and a metallized electrode, after a semiconductor device is mounted on the wiring board. CONSTITUTION:A semiconductor element is mounted on the inside of a ceramic substrate 1, and metallized electrodes 2 having electric conduction to the semiconductor element are arranged on the periphery of the upper surface. Then a semiconductor device is bonded on a printed wiring board 3; wiring electrodes 4 of a copper foil patterned on the board 3 and the electrodes 2 on the substrate 1 are subjected to solder connection by using insulative clad wires. The wires 5 of solder connection part 6 on the package side and solder connection part 7 on the board 3 side are subjected to solder connection by exfoliating the coating of the connection parts 6, 7. Thereby the imperfect fixing of outer leads and the bending of leads are not necessary to be considered, and the electrodes 2, 4 are precisely connected.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a mounting structure for a semiconductor device, and particularly to a connection structure for external leads of a flat package type semiconductor device.

[Conventional technology]

The structure of a conventional semiconductor device of this type is shown in FIG. The external lead 9 is etched or pressed into a shape that is supported by the tieper 10. External leads 9 are connected to metalized electrodes 2 arranged on the outer periphery of the upper surface of the ceramic substrate 1 on which the LSI chip is mounted.
) By brazing, a ceramic flat package type semiconductor device is constructed. here typer 10
This prevents deformation of the external lead 9 and enables lead brazing and handling after brazing. The ceramic package (flat package) manufactured in this way goes through processes such as mounting the semiconductor element, sealing, shaping the leads (tie bar cutting and bending or shaping the leads), and sorting at the semiconductor device manufacturer, and then becomes a semiconductor device. It will be completely destroyed.

As shown in FIGS. 5(a) and 5(b), when mounted on the printed wiring board 14 using glass epoxy or the like, four rows of wiring electrodes patterned by etching, for example, a row of copper foil electrodes, are After positioning the external leads 9 of the package, they were mechanically and electrically connected by solder reflow or the like.

[Problem to be solved by the invention]

Currently, semiconductor devices are required to have multiple bins in packages due to the higher integration of semiconductor elements. Therefore, as the wiring mounting density of printed wiring boards such as glass epoxy improves, the package external lead pitch becomes finer (0.
．． 4mm pitch or less) is required.

In the conventional semiconductor device described above, when the external leads are brazed to the metallized electrodes arranged around the outer periphery of the package,
When the metallized electrode pitch and metallized width are small (pitch 0.4 mm or less), the external lead brazing position protrudes from the metallized electrode due to dimensional variations during ceramic firing, resulting in a decrease in the manufacturing yield of ceramic packages. In addition, it has the disadvantage of increasing the unit price of the package, and handling of the package during assembly processes such as semiconductor element mounting, wire bonding, sealing, finishing, and sorting can lead to lead bending defects, which causes a decrease in yield. There was a problem. Next, there is a possibility that lead bending may occur during processes such as lead cutting and lead bending that involve separating tie bars.

Furthermore, during the sorting process, packages with fine-pitch external leads require a complicated and expensive carrier that serves as a guide between the external leads in order to make accurate electrical contact between the socket electrodes attached to the LSI tester and the external leads. I needed it.

Moreover, even with this carrier, perfect electrical contact was not guaranteed.

Furthermore, when mounting a conventional semiconductor device on a glass epoxy wiring board, there is a drawback that high precision is required for positioning the external leads with respect to the copper foil electrode array.

〔the purpose〕

The purpose of this example is that in the assembly process performed before mounting on the wiring board, external leads are not attached to the metallized electrodes of the ceramic board, and after mounting on the wiring board, the electrodes on the wiring board and the metallized To provide a semiconductor device mounting structure that prevents lead bending, electrical contact failure, etc. that occur during the assembly process by connecting a covered conductor between electrodes, and improves assembly workability and product yield. It is something.

[Means to solve the problem]

The semiconductor device mounting structure of the present invention is a semiconductor device having metallized electrodes arranged on the outer periphery of the upper surface of a ceramic substrate on which a semiconductor element is mounted and electrically connected to the semiconductor element. When mounted on a wiring board or the like, the metallized electrode of this semiconductor device and the corresponding wiring electrode on the printed circuit board are connected using an insulated conductive wire.

This mounting structure eliminates external leads that cause deformation of leads and poor electrical contact during the various assembly and sorting processes performed before mounting on a printed circuit board, and improves the reliability of semiconductor devices that are mounted after mounting. This prevents short circuits between leads when electrically connecting to a printed circuit board. [Example] Next, a first example of the present invention will be described with reference to the drawings.

As shown in FIG. 1(a), in a semiconductor device in which a semiconductor element is mounted inside a ceramic substrate 1 and metallized electrodes 2 that are electrically connected to the semiconductor element are arranged on the outer periphery of the upper surface, a material such as glass epoxy is used. Finishing processes, sorting, burn-in, etc. are performed before mounting the printed wiring board. Thereafter, as shown in FIGS. 1(b) and 1(C), the semiconductor device is mounted on the printed wiring board 3 with an adhesive or the like, and wiring electrodes 4 such as copper foil patterned on the printed wiring board 3. and metallized electrode 2 on the top surface of ceramic substrate 1.
and are electrically connected by soldering using an insulated conductive wire 5. At this time, the coated conductive wires 5 in the package side solder connection part 6 and the printed wiring board side solder connection part 7 are connected by soldering after peeling off the coating of the solder connection part.

With such a mounting structure, there is no need to take into account poor attachment of external leads, bending of leads, etc. in various steps before semiconductor device mounting. In addition, the coated conductive wire that connects the metallized electrode and the electrode on the printed circuit board can be made with high precision by optionally improving the wire bonding device, etc.
Can be installed.

Next, a case where the first embodiment is applied to a semiconductor device having a multi-terminal structure will be described using FIG. Figure 2 (a
), As shown in (b), the ceramic substrate 1' is
It has a two-tier ceramic laminated structure, with a lower metallized electrode 2' and an upper metallized electrode 2'' arranged on the outer periphery of the upper surface of the ceramic substrate 1'.Furthermore, the printed wiring board 3' has a metallized Electrode 2'
and 2'', a lower wiring electrode 4' and an upper wiring electrode 4'' are provided. First, the lower metallized electrode 2' and the lower wiring electrode 4' are connected by soldering with the lower coated conductor 5' in the same manner as in the first embodiment.
Next, as shown in FIGS. 2(c) and 2(d), the upper metallized electrode 2'' and the upper wiring electrode 4'' are connected by soldering with the upper coated conductor 5''.This application example is based on the implementation shown in FIG. For example, by taking advantage of the feature that short circuits between leads can be prevented by using coated conductor wires, by arranging coated conductor wires, which are external leads, in two or more stages in the height direction, semiconductor devices can have multiple terminals and high It has the characteristic of being able to handle functionalization.

FIG. 3 is a perspective view showing a second embodiment of the invention. In this embodiment, the metallized electrode 2 and the wiring electrode 4 such as copper foil do not use separate covered conductor wires in a one-to-one correspondence.
Match the wiring pitch of metallized electrode 2 and wiring electrode 4,
It is characterized in that a flat cable 8 shaped to match this pitch is used for solder connection instead of a coated conductor.

In this embodiment, the flat cables 8 can be soldered to each side of the ceramic substrate 1 all at once, which has the advantage of improving workability, simplifying the structure, and increasing the connection strength of the external leads.

〔Effect of the invention〕

As explained above, the present invention mounts a flat package type semiconductor device to which no external leads are attached on a printed wiring board, etc., and uses a coated conductive wire as the external lead to connect the metallized electrode of the semiconductor device and the electrode of the printed wiring board. By making a solder connection between the two, it becomes unnecessary for the package manufacturer to braze the external leads to the ceramic substrate, thereby improving product yield and reducing the unit price of the package. Furthermore, it is possible to prevent lead bending during the assembly process by semiconductor device manufacturers, improve assembly workability and assembly yield, improve workability during sorting, and simplify the sorting box structure. Furthermore, when mounting this semiconductor device on a printed wiring board or the like, for example, when connecting external leads to wiring electrodes by soldering, it is possible to prevent defects such as short-circuiting between the leads due to bending of the external leads.

FIG. 2(b) and (d) are sectional views of main parts of FIGS. 2(a) and (c); FIG. 3 is a perspective view showing the second embodiment; FIG. 4 is a perspective view showing a conventional example, and FIG.
FIG. 5(b) is a sectional view of a main part of FIG. 5(a).

1,1'...Ceramic substrate, 2.2'2''・
...Metallized electrode, 3,3'...Printed wiring board, 4.4'4"...Wiring electrode, 5,5',5"... Covered conductor, 6...
・Package side solder connection part, 7...Solder connection part on glass epoxy board side, 8...Flat cable, 9...External lead, 10...Tie bar .

Claims (1)

[Claims] In a structure in which a semiconductor device is mounted on a printed wiring board, in which metallized electrodes electrically connected to the semiconductor element are arranged on the outer periphery of the upper surface of a ceramic substrate on which a semiconductor element is mounted, the metallized electrode of the semiconductor device and the metallized electrode of the semiconductor device are arranged. A mounting structure for a semiconductor device, characterized in that a wiring electrode formed on the printed wiring board corresponding to the metallized electrode is connected using an insulated conductive wire.