JPH06120417A - Multi-chip module mounting structure and manufacturing method thereof - Google Patents

Abstract

(57) [Abstract] [Purpose] To prevent damage to the pads of the wiring board in the inspection process to improve productivity, and to improve reliability of the connection of each part during manufacturing. [Structure] A mounting structure of a multi-chip module in which a semiconductor device in which four semiconductor elements 100a to 100d are mounted on one wiring board 200 is housed in a hermetically sealed package, and a lead 300 is connected to a printed circuit board. The semiconductor element connecting material 610 having a melting point higher than that of the lead connecting material 630 is used to connect the semiconductor elements 100a to 100d to the wiring board 200, and the wiring board connecting has a melting point higher than that of the semiconductor element connecting material 610. The encapsulating material 70 that connects the lead 300 and the wiring board 200 with the application material 620 and cures at a temperature lower than the temperature required to connect the semiconductor element connection material 610.
The package 400 is hermetically sealed by 0.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention
The present invention relates to a mounting method of a multi-chip module mounted on one wiring board and a manufacturing method thereof.

[0002]

2. Description of the Related Art A multi-chip module in which a plurality of semiconductor elements are mounted on one wiring board and the wiring boards are packaged in one package does not have a uniform mounting form, and various forms are invented. It has been implemented. For example, there is one in which a semiconductor element and a wiring board are connected by a flip chip method. This will be described with reference to FIGS. 4 and 5.

As shown in FIG. 5, the general manufacturing process of the multi-chip module having such a form is as follows.
100a to 100d (However, in FIG. 4, semiconductor elements 100b and 100d
(Only shown) and the wiring board 200 (see FIG. 5).
S reference _1), after the test and the connection state between the test and the semiconductor elements 100a to 100d and the wiring board 200 of the electrical characteristics of the semiconductor devices 100a to 100d, the replacement of defective elements if necessary Perform (see S _{2 in} FIG. 5) and finally package.

The hermetically sealed package 400 is of a type in which a cap is simply attached to the package base, such as a pin grid array, and between the cap 420 and the package base 410, as shown in FIG. Lead 300
There is a type (hereinafter referred to as a "circled package") that is sealed by sandwiching. The cost of the sarkud package can be lower than that of the pin grid array.

In the final packaging step of the circud package, a sealing material 700 is applied to the package base 410 and the cap 420 in advance (see S _{7 in} FIG. 5),
The lead 300 with a frame is mounted on the package base 410 (see S _{8 in} FIG. 5), and the wiring board 200 on which the semiconductor elements 100a to 100d are previously mounted is adhered to the package base 410 (see S _{3 in} FIG. 5). After wire-bonding the pad of the wiring substrate 200 and the lead 300 with the thin metal wire 800 (see S _{4 in} FIG. 5), the package base 410 is covered with the cap 420 to heat and seal the sealing material 700 (see FIG. 5 S ₅ ). Further, the lead 300 is separated from the frame and the shape of the lead 300 is adjusted to complete a series of steps (see S _{6 in} FIG. 5).

[0006]

However, the above-mentioned circd package has the following problems. That is, the inspection of the electrical characteristics of the semiconductor element, etc.
Since the tester probe is brought into contact with the pad of the wiring board, the pad may be damaged after the defective element is replaced. Therefore, wire bonding performed thereafter may become uncertain. Further, since wire bonding is performed by reciprocally moving the capillary between the pad and the lead, the productivity is inferior to the collective connection. Further, since a low melting point glass is usually used for sealing the circd package, a temperature of about 300 to 400 ° C. is required for sealing, but flip chip connection between the semiconductor element and the wiring board is required. Melting point 300
Since the solder bumps of about ℃ are used, the reliability of the solder bumps is deteriorated at the time of sealing.

The present invention was devised in view of the above circumstances, and prevents damage to the pads of the wiring board in the inspection process to improve productivity and improves reliability of the connection of each part during manufacturing. An object is to provide a mounting structure of a multi-chip module and a manufacturing method thereof.

[0008]

A mounting structure of a multi-chip module according to the present invention is a mounting of a multi-chip module in which a semiconductor device having a plurality of semiconductor elements mounted on one wiring board is housed in a hermetically sealed package. The structure is such that the semiconductor element and the wiring board are connected by a semiconductor element connecting material having a melting point higher than that of the lead connecting material for connecting the lead and the printed circuit board, and a melting point higher than that of the semiconductor element connecting material. The lead and the wiring board are connected by the wiring board connecting material having the above, and the package is hermetically sealed by the sealing material which is cured at a temperature lower than the temperature required for connecting the semiconductor element connecting material.

Further, in the method for manufacturing a multi-chip module according to the present invention, leads are collectively connected to a wiring board on which a plurality of semiconductor elements are mounted, then the semiconductor elements are mounted on the wiring board, and then Then, a semiconductor element inspection step is performed, and then the semiconductor element is hermetically sealed.

[0010]

FIG. 1 is a view showing a manufacturing process of a mounting structure of a multi-chip module according to an embodiment of the present invention,
1A is a flowchart, FIG. 2B is an explanatory diagram corresponding to the flowchart, FIG. 2 is a schematic sectional view of a semiconductor device having a mounting structure of this multichip module, and FIG. 3 is mounting of this multichip module. FIG. 3 is a plan view of a semiconductor device having a structure with a package cap removed. It should be noted that parts and the like that are substantially the same as the conventional ones will be given the same reference numerals for the description.

The semiconductor device having the mounting structure of the multi-chip module according to this embodiment has four semiconductor elements 100a.
˜100d, a wiring board 200 on which the wiring board 200 is mounted, leads 300 connected to the wiring board 200, and the semiconductor element 10
And a package 400 that hermetically seals 0a to 100d.

The package 400 includes a package base 41 having a base-side recess 411 in which the wiring board 200 is fitted.
0 and the cap that covers this package base 410
And 420. On the back side of the cap 420, the cap-side recess 42 corresponding to the base-side recess 411 is formed.
1 is recessed. Further, a sealing material filling groove 412 is provided so as to surround the base side recess 411 of the package base 410.

A plurality of wiring boards 200 (4 in the drawing)
Individual semiconductor devices 100a to 100d are mounted. Further, the wiring board 200 is formed with a plurality of pads (not shown). This pad is the semiconductor device 100a ~
This is the portion that will be the extraction electrode of 100d. The wiring board 200 is, of course, formed in a shape and size corresponding to the base side recess 411.

The lead 300 is a semiconductor device printed circuit board.
It is used for mounting on the package 500, and is connected to the pad and led out to the outside of the package 400.

The melting point of the semiconductor element connecting material 610 for connecting the semiconductor elements 100a to 100d and the wiring board 200 is T ₁ , and the wiring board connecting material for connecting the wiring board 200 and the lead 300.
620 melting point T _2, when the melting point of the lead connecting material 630 which connects the connection of the leads 300 and the printed circuit board 500 and T _3, the _{T 3 <T 1 <T 2} . This is because if the eutectic solder, which is the most commonly used solder, is used for the lead connecting material 630, the semiconductor element connecting material 610 has a higher lead content than the eutectic solder, and the wiring board The connecting material 620 is realized by further increasing the lead content.

Next, the manufacturing process of the semiconductor device having the mounting structure of the multi-chip module according to this embodiment will be described. First, connect the wiring board 200 to the package base 410
Fit into the base-side recessed part 411 to connect (Fig. 1 (A)
(See S _{1 in} Figure ₁ and Figure (B)). The material used for this connection must have sufficient heat resistance to withstand the subsequent steps.

Next, the lead 300 with a frame is connected to the pad of the wiring board 200 (S _{2 in} FIG. 1A and the same figure).
(See (B)). For this connection, the wiring board connecting material 620 having the highest melting point T ₂ is used. Reed 30
When the connection of 0 to the wiring board 200 is completed, the lead 30
Disconnecting the 0 from the frame (see S ₃ of FIG. 1 (A)).

[0018] connecting the semiconductor element 100a~100d the wiring board 200 (see S ₄ in FIG. 1 (A)). For this connection, a semiconductor element connecting material 610 having a melting point T ₁ lower than that of the wiring board connecting material 620 is used. That is, the treatment is performed at a lower temperature than the previous step (the step of connecting the lead frame 300 and the wiring board 200).

The electrical characteristics of the semiconductor devices 100a to 100d are inspected. This inspection is performed by bringing the probe of the tester into contact with the lead 300. If a defective element, defective connection, etc. are found, they are replaced and repeated until they pass the inspection (see S _{5 in} FIG. 1 (A)).

All the semiconductor devices 100a to 100d are good products,
If the connection is good, the encapsulating material filling groove 412 is filled with the encapsulating material 700 (see S _{6 in} FIG. 1A and FIG. 1B), and the package base 410 is covered with the cap 420. . Then, the encapsulating material 700 is immediately cured to enclose the package 400 (S _{7 in} FIG. 1A and FIG. 1B).
). The sealing material 700 is hardened at a temperature lower than the melting point T ₂ of the semiconductor element connecting material 620.

When the package 400 is completely sealed,
The lead 300 led out of the package 400 is shaped into a predetermined shape (see S _{8 in} FIG. 1A).

As a result, the semiconductor device is completed. When mounting such a semiconductor device on the printed circuit board 500,
A lead connecting material 630 having a melting point T _{1 of} the semiconductor element connecting material 610 and a melting point T ₃ lower than the melting point T _{2 of} the wiring board connecting material 620, that is, eutectic solder is used. Therefore, the semiconductor element connecting material 610 and the wiring board connecting material 620 are not melted by the mounting work of the semiconductor device with the lead connecting material 630.

In the embodiment described above, the wiring board 200
After connecting the lead 300 to the package base 410, the lead 300 was connected to the wiring board 200.
After connecting the wiring board 200 to the package base
It may be connected to 410. However, in this case, the connection between the wiring board 200 and the package base 410 needs to be performed with a material having sufficient heat resistance to withstand the subsequent steps.

Further, in the above-described embodiment, the wiring board 200 is fitted in the base side recess 411 of the package base 410, but the wiring board 20 is previously mounted in the package base 410.
It is also possible to integrally form 0.

[0025]

The mounting structure of a multi-chip module according to the present invention is a mounting structure of a multi-chip module in which a semiconductor device having a plurality of semiconductor elements mounted on one wiring board is housed in a hermetically sealed package. A wiring board having a melting point higher than that of the semiconductor element connecting material, while connecting the semiconductor element and the wiring board with a semiconductor element connecting material having a melting point higher than that of the lead connecting material for connecting the lead and the printed board Since the lead and the wiring board are connected with a connecting material, and the package is hermetically sealed by a sealing material that is cured at a temperature lower than the temperature required for connecting the semiconductor element connecting material,
In each process, the treatment can be performed at a lower temperature than the previous process. Therefore, it is possible to secure the reliability of the portion where the connection is completed by the previous process.

In the method for manufacturing a multi-chip module according to the present invention, leads are collectively connected to a wiring board on which a plurality of semiconductor elements are mounted, and then the semiconductor elements are mounted on the wiring board, and then Since the semiconductor element is inspected, the semiconductor element is hermetically sealed thereafter, so that the probe can be brought into contact with the lead in the inspection of the semiconductor element. Therefore, the pad of the wiring board is not damaged unlike the conventional case, and the productivity can be improved.

[Brief description of drawings]

1A and 1B are drawings showing a manufacturing process of a mounting structure of a multi-chip module according to an embodiment of the present invention, wherein FIG. 1A is a flowchart and FIG. 1B is an explanatory diagram corresponding to the flowchart. .

FIG. 2 is a schematic cross-sectional view of a semiconductor device having a mounting structure of this multichip module.

FIG. 3 is a plan view of the semiconductor device having the mounting structure of the multi-chip module with the cap of the package removed.

FIG. 4 is a schematic cross-sectional view of a semiconductor device having a conventional mounting structure for a multi-chip module of this type.

FIG. 5 is a flowchart of a manufacturing process of a semiconductor device having a conventional mounting structure of a multi-chip module of this type.

[Explanation of symbols]

 100a to 100d Semiconductor element 200 Wiring board 300 Lead 400 Package 610 Semiconductor element connecting material 620 Wiring board connecting material 630 Lead connecting material

Claims (4)

[Claims] 1. A lead connection for connecting a lead and a printed circuit board in a mounting structure of a multi-chip module in which a semiconductor device having a plurality of semiconductor elements mounted on one wiring board is housed in a hermetically sealed package. While connecting the semiconductor element and the wiring board with a semiconductor element connecting material having a higher melting point than the material, connecting the lead and the wiring board with a wiring board connecting material having a higher melting point than the semiconductor element connecting material, A packaging structure for a multi-chip module, wherein a package is hermetically sealed with a sealing material that cures at a temperature lower than a temperature required for connecting a semiconductor element connecting material. 2. The mounting structure for a multi-chip module according to claim 1, wherein the wiring board is formed integrally with a package base that constitutes a package. 3. A groove for filling a sealing material, which is filled with a sealing material connecting the package base and the cap, which form the package, is formed in at least one of the package base and the cap. The mounting structure for a multi-chip module according to claim 1 or 2. 4. A lead is collectively connected to a wiring board on which a plurality of semiconductor elements are mounted, then the semiconductor element is mounted on the wiring board, and then a semiconductor element inspection step is performed, and then the semiconductor is mounted. A method for manufacturing a multi-chip module, characterized in that an element is hermetically sealed.