JPH077120A - Mounting structure for semiconductor device, mounting board and semiconductor device - Google Patents

Abstract

PURPOSE:To avoid projection of a semiconductor device from a mounting board by forming a receiving recess in a mounting board body, inserting a semiconductor device therein, and connecting the outer leads of the semiconductor device electrically and mechanically with contacts formed around the opening of the recess. CONSTITUTION:A semiconductor device 15 is inserted into a receiving hole 24 made in a mounting board 22 with the end face side thereof, from which a group of outer leads 8 of a package 4 projects, directing upward. Consequently, each outer lead 8 of the semiconductor device 15 is connected, on the lower face side thereof, with a solder cream placed on each land 25 formed around the opening of the receiving hole 24 made in the upper face of the mounting board 22. When the solder cream is fused by reflow soldering and eventually solidified, each outer lead 8 is connected electrically and mechanically with the land 25 through a solder bump layer 27. This structure allows mounting of the semiconductor device 15 onto the mounting board 22 without projecting the device 15 from the upper face of the board 22 thus realizing reduction of overall height.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor device mounting technique, and more particularly to an epoch-making semiconductor device mounting technique capable of mounting a semiconductor device so as not to project from the main surface of a mounting substrate. Semiconductor integrated circuit device (hereinafter referred to as IC
Say. ) Related to the effective implementation technology.

[0002]

2. Description of the Related Art The conventional IC mounting technology is as follows. (1) IC equipped with a single in-line package or dual in-line package (SIP
-IC, DIP, IC, etc.) such as an IC having an outer lead of an in-line structure is mounted on a mounting board, the mounting board body is provided with a plurality of insertion openings having a contact structure. The outer lead group is inserted into the insertion port group, and the contact between the insertion port and the outer lead are soldered to each other, whereby the IC is mounted in a state of being lifted on the mounting substrate.

Incidentally, as an example in which the DIP type automatic component insertion technology is described, "Introduction to Automatic Assembly of Electronic Components" issued by Nikkan Kogyo Shimbun, July 30, 1981, P135-P1
There are 37.

(2) I equipped with a small outline package or a quad flat package
When an IC such as C (SOP / IC, QFP / IC) having an outer lead of an outline structure is mounted on a mounting board, a plurality of lands having a contact structure are provided on the main surface of the mounting board body. The outer lead groups are respectively brought into contact with the land group, and the land and the outer lead are soldered to each other, so that the IC is mounted on the mounting board in a state of being supported (surface mounted). To be done.

An example of the surface mount technology is "1989 Surface Mount Technology" issued by Press Journal Co., Ltd., issued August 25, 1988.

[0006]

However, the conventional semiconductor device mounting technology has the following problems.

(1) In a semiconductor device provided with an outer lead having an in-line structure, since the semiconductor device projects from the surface of the main body of the mounting substrate when the semiconductor device is mounted on the mounting substrate, the total thickness after mounting is as a whole. Get thicker.

(2) In a semiconductor device having an outer lead having an outline structure, since the outer lead is soldered to the land, not only the area occupied by the semiconductor device on the mounting board becomes large, but also the thickness of the package increases. Will inevitably project onto the mounting board.

An object of the present invention is to provide a semiconductor device mounting technique which can prevent the semiconductor device from protruding from the mounting substrate.

A second object of the present invention is to provide a semiconductor device mounting technique capable of reducing the occupied area of the semiconductor device on the mounting substrate.

The above and other objects and novel features of the present invention will be apparent from the description of this specification and the accompanying drawings.

[0012]

The typical ones of the inventions disclosed in the present application will be outlined below. That is, a mounting board in which a housing recess is formed in the main body, and a contact is arranged at an opening edge portion of the housing recess on one main surface of the main body, and a package housed in the housing recess of the mounting board are provided. And a semiconductor device in which an outer lead is provided so as to protrude from the one main surface side end portion of the outer peripheral surface of the package so as to face the contact, and the semiconductor device is mounted on the mounting substrate as the package. Is housed so as to be entirely immersed in the housing recess, and the outer lead is mounted in a state of being electrically connected to the contact.

[0013]

According to the above-mentioned means, since the semiconductor device is housed so as to be entirely submerged in the housing recess of the mounting substrate body, the semiconductor device is suppressed from projecting from the surface of the mounting substrate to an extremely small level. .

Further, since the outer lead group of the semiconductor device is arranged on the opening edge of the accommodation recess on the one main surface of the mounting substrate, the area occupied by the outer lead group on the mounting substrate can be suppressed to the minimum.

[0015]

1 shows a mounting structure of a semiconductor device according to an embodiment of the present invention, in which (a) is a front sectional view and (b) is a sectional view.
Is a partially omitted plan view with some parts omitted. FIG. 2 shows a mounting board used for it, (a) is a perspective view,
(B) is sectional drawing which follows the bb line | wire of (a). 3 and subsequent drawings are explanatory views showing a method of manufacturing a semiconductor device according to an embodiment of the present invention.

In this embodiment, a semiconductor device mounting structure 21 according to the present invention includes a mounting substrate 22 and a semiconductor device 15 including a semiconductor integrated circuit device.

The mounting substrate 22 which is an embodiment of the present invention includes a main body 23, and the main body 23 is formed in a desired flat plate shape using an insulating material such as resin or ceramic. The main body 23 has a housing hole 24 as a housing recess.
Are arranged at desired locations and are integrally formed so as to penetrate in the thickness direction, and the internal space of the accommodation hole 24 is formed in a substantially square pillar shape capable of accommodating the semiconductor device 15. .

One main surface of the main body 23 (hereinafter referred to as the upper surface).
A plurality of lands 25 as contacts are formed on the four sides of the opening edge of the accommodation hole 24 in the above. Each of the lands 25 is arranged at equal intervals in the circumferential direction with a predetermined pitch, and is formed so as to extend in the radial direction. The pitch of each land 25 group is set so as to correspond to the pitch of the outer leads of the semiconductor device described later.

The land 25 is formed in a substantially rectangular small plate shape, and its size is set to be slightly larger than the outer lead of the semiconductor device described later. Then, a solder cream (not shown) is applied to the upper surface of each land 25 by an appropriate means such as a screen printing method. With this solder cream, the solder layer 2
7 are formed.

Each land 25 is electrically connected to an electric wiring 26 formed on the upper surface of the main body 23 where the accommodation hole 24 is opened. The electric wiring 6 may be formed in advance on the upper surface of the main body 23 by an appropriate thick film forming technique such as a screen printing method, but as described later, the semiconductor device is immersed in the accommodation hole 24. After that, it can also be formed by a screen printing method or the like.

On the other hand, the semiconductor device 15 according to the present embodiment is
Silicon semiconductor pellet (hereinafter referred to as pellet) 1
2, the plurality of inner leads 7 arranged around the pellet, the outer leads 8 integrally connected to the inner leads 7, the bonding pads 12a of the pellet 12 and the inner leads 7. A wire 13 bridging and bridging both ends thereof to the tip part, and a package 14 for sealing them with resin
It has and. A group of outer leads 8 are provided so as to project outward in the radial direction on the one main surface side end portion of the outer peripheral surface of the resin-sealed package 14, and the radial length of each outer lead 8 is set to about 0.8 mm or less. It is formed to be short.

A method of manufacturing this semiconductor device, which is an embodiment of the present invention, will be described below. From this description, details of the configuration of the semiconductor device will be clarified together.

In this embodiment, the multiple lead frame 1 shown in FIG. 3 is used in the method of manufacturing the semiconductor device having the above structure. The multiple lead frame 1 is a thin plate made of a copper-based material (copper or its alloy) and is integrally formed by an appropriate means such as punching press working or etching working.

On this multiple lead frame 1, a plurality of unit lead frames 2 are arranged side by side in a row in the lateral direction. However, only one unit is shown and described. The unit lead frame 2 includes a pair of outer frames 3 each having a positioning hole 3a. The outer frames 3 and 3 are arranged in parallel at a predetermined interval and are extended in series.
A pair of section frames 4 are provided between the unit lead frames 2 and 2 adjacent to each other so as to be parallel to each other between the outer frames 3 and 3 and are integrally installed. The outer frames 3 and 3 and the section frame 4, The unit lead frame 2 is formed in a substantially square frame formed by 4.

The outer frame 3 of each unit lead frame 2
Further, dam suspension members 5 are arranged at substantially right angles to the connecting portion of the section frame 4 and are integrally projected.
Four dam members 6 are arranged on the dam suspension member 5 so as to have a substantially square frame shape and are integrally suspended.

A plurality of inner leads 7 are arranged on the dam member 6 at equal intervals in the longitudinal direction, and are radially inwardly projected so as to extend substantially radially. Each of the inner leads 7 is provided. The tips are arranged in a line.

On the other hand, the inner lead 7 in the dam member 6
On the opposite side, a plurality of outer leads 8 are arranged so that each is integrally continuous with each inner lead 7, and are integrally projected so as to be parallel to each other and at right angles to the dam member 6. It is set up. The outer ends of the outer leads 8 are connected to the outer frame 3 or the section frame 4, respectively. The distance from the dam member 6 of the outer lead 8 to the outer frame 3 or the section frame 4 is set to be extremely short. Therefore, the outer ends of the outer leads 8 may be separated from the outer frame 3 or the section frame 4 in advance.

The portion of the dam member 6 between the adjacent inner leads 7, 7 and outer leads 8, 8 is
A dam 6a that substantially blocks the flow of the resin at the time of molding a resin-sealed package, which will be described later, is substantially configured.

In the present embodiment, the inner lead 7 group is separated from the plane including the dam member 6 in the vicinity of the dam member 6 in one direction (hereinafter, referred to as downward direction) by about 45.
It is bent with an inclination angle of degrees. Further, the inner lead 7 group is bent inward in the horizontal direction near the inclined lower end which is near the tip of the inner lead. Therefore, the inner end portion of the inner lead 7 group is lowered downward from the plane including the dam member 6, and the lowered height is set to be equal to or more than the thickness of the pellet.

Then, the tab member mounting portion 9 is substantially formed by the lowered and horizontally formed portion of the inner lead 7 group, and the tab member 1 is formed on the lower surface of this mounting portion 9.
0 is fixed. The tab member 10 is formed by using a tape made of an insulating resin, and is fixed to the lower surface of the mounting portion 9 by an appropriate means such as adhesion.

Pellet bonding work and then wire bonding work are carried out on the multiple lead frame having the above-mentioned structure, and by these works, an assembly as shown in FIG. 4 is manufactured. Become.

First, by pellet bonding work,
A pellet 12 as a semiconductor integrated circuit structure in which a bipolar type integrated circuit element or the like (not shown) is formed in the previous step is arranged on the tab member 10 in each unit lead frame 2 at a substantially central portion. , A silver paste or the like is used as a bonding material, and the bonding layer 11 is fixed. The silver paste is a bonding material composed of an epoxy resin adhesive, a curing accelerator, and a solvent mixed with silver powder.
The bonding layer 11 is formed by pressing the pellets onto the silver paste coated on the surface of the substrate 0 and then curing (curing) at an appropriate temperature.

In this embodiment, the pellet 12
Is bonded to the tab member 10, the tab member 1
It is also possible to bond the pellets 12 to 0 in advance and bond the tab member 10 to which the pellets 12 are bonded to the tab attachment portion 9 of the unit lead frame 2. In this case, by connecting a plurality of tab members 10 in a tape shape arranged so as to correspond to each unit lead frame 2 of the multiple lead frame 1, a plurality of pellets 12 are multiply joined. The lead frame 1 can be collectively bonded. Further, the tapes of the tab member group 10 and the multiple lead frame 1 are sent in synchronism with each other in the same direction, whereby the pellet bonding work can be executed sequentially and continuously.

Then, the bonding pad 12a of the pellet 12 fixedly bonded to the tab member 10 is formed.
And a wire 13 formed of a gold-based material, a copper-based material, an aluminum-based material, or the like between the unit lead frame 2 and each inner lead 7 are suitable such as ultrasonic thermocompression bonding type. By using such a wire bonding device, both ends thereof are bonded and bridged. As a result, the integrated circuit built in the pellet 12 is electrically drawn to the outside through the bonding pad 12a, the wire 13, the inner lead 7 and the outer lead 8.

For the multiple lead frames thus pellet-bonded and wire-bonded as described above, a package group for resin-sealing each unit lead frame is used by using a transfer molding apparatus as shown in FIG. The unit lead frame group is simultaneously molded.

The transfer molding apparatus 50 shown in FIG. 5 includes an upper mold 51 and a lower mold 52 which are clamped to each other by a cylinder device or the like (not shown). Lower mold 52
The lower mold cavity recess 53 is provided on the mating surface with the upper mold 51.
A plurality of sets of b are submerged so as to cooperate with the mating surface 53a of the upper mold 51 to form the cavity 53 having substantially the same depth as the accommodation hole 24 in the mounting substrate 22. However, only one unit is shown.

A pot 54 is provided on the mating surface of the upper die 51, and a cylinder device (not shown) is provided in the pot 54.
A tablet made of a resin as a molding material is put into the plunger 55 which is moved forward and backward by this, and a resin (hereinafter, referred to as a resin) made by melting the tablet can be fed.

On the mating surface of the lower mold 52, a cull 56 is arranged at a position facing the pot 54 and is sunk.
A plurality of runners 57 are radially arranged so as to be respectively connected to the pots 54 and are recessed. The other end of each runner 57 is connected to the lower cavity recess 53b, and a gate 58 is formed at that connection so that the resin can be injected into the cavity 53. In addition, in the mating surface of the lower mold 52, a rectangular shape slightly larger than the outer shape of the multiple lead frame 1 is provided so that an escape recess 59 can escape the thickness of the lead frame, and a constant depth approximately equal to the thickness thereof. It is buried in.

When the resin-sealed package is transfer-molded by using the multiple lead frame 1 having the above structure, each cavity 53 in the upper mold 51 and the lower mold 52 has a pair of dams in each unit lead frame 2. It corresponds to the space between 6a and 6a, respectively.

At the time of transfer molding, the multiple lead frame 1 having the above-described structure has the recesses 59 formed in the lower mold 52, and the pellets 12 in each unit lead frame 2 are accommodated in the lower mold cavity recess 53b. It is arranged and set so as to be housed in each. In this state, the pellet 12 is lowered and bonded to the tab member 10 of the inner lead 7 group.
It is located near the bottom surface of the lower mold cavity recess 53b.

Subsequently, when the upper mold 51 and the lower mold 52 are clamped to form the respective cavities 53, the resin 60 as the molding material is passed from the pot 54 to the plunger 55 through the runner 57 and the gate 58. It is sent to the cavity 53 and injected.

After the injection, when the resin is thermoset to mold the resin-sealed package 14, the upper mold 51 and the lower mold 52 are formed.
The mold is opened and the group of resin-sealed packages 14 is released from the mold by ejector pins (not shown). In this way, the multiple lead frame 1 on which the group of resin-sealed packages 14 is molded is detached from the transfer molding device 50.

The resin-sealed package 14 resin-molded in this manner has a substantially square flat plate shape slightly smaller than the internal space of the accommodation hole 24 formed in the mounting substrate 22. Inside the resin-sealed package 14, the pellet 12, the tab member 10, the inner lead 7 and the wire 13 are resin-sealed. In addition, each outer lead 8 is in a state of protruding from the four sides on the upper surface side of the resin-sealed package 14 at right angles to the outside.

The multiple lead frame 1 in which the resin-sealed package is molded is sequentially processed for each unit lead frame by a lead cutting device (not shown) in the lead cutting molding process, and the outer frame 3, the section frame 4, and the dam are formed. 6a is cut off.

When the outer frame 3 and the section frame 4 are cut off, each outer lead 8 is in a molded state. At this time, each of the outer leads 8 is cut and formed on the four sides on the upper surface side of the resin-sealed package 14 so as to project to the outside extremely shortly. For example, the length of the outer lead 8 is set to 0.8 mm or less.

Next, the mounting work of the mounting structure of the semiconductor device which is an embodiment of the present invention in which the mounting substrate and the semiconductor device having the above-mentioned structure are used will be described. This description clarifies the configuration of the mounting structure of the semiconductor device which is an embodiment of the present invention.

The semiconductor device 15 having the above structure is inserted into the accommodation hole 24 of the mounting substrate 22 having the above structure with the end surface side of the package 14 on which the outer lead 8 group is provided protruding upward. By this insertion, the lower surface of each outer lead 8 of the semiconductor device 15 is accommodated in the accommodation hole 2 on the upper surface of the mounting substrate 22.
4 is adhered on the solder cream of each land 25 formed on the edge of the opening 4.

After that, when the solder cream applied on the land 25 is melted and solidified by the reflow soldering process, each outer lead 8 and the land 25 are electrically connected by the solder pile layer 27 formed by the reflow soldering process. And mechanically connected. In this way, the outer lead 8 and the land 25 are electrically and mechanically connected to each other, so that the semiconductor device 15 is electrically and mechanically mounted on the mounting substrate 22.

The semiconductor device 15 has the housing hole 2 of the mounting substrate 22.
4 and the group of outer leads 8 is mechanically and electrically connected to the group of lands 25, the semiconductor device 1
0 is in a state in which it is not projected at all from the upper surface of the main body 23 of the mounting substrate 22. Therefore, even after the semiconductor device 15 is mounted on the mounting board 22, the electric wiring 26 can be formed on the upper surface of the mounting board body 23 by the screen printing method.

According to the above described embodiment, the following effects can be obtained. (1) An accommodation hole is formed in the mounting substrate body, the semiconductor device is inserted into the accommodation hole, and the outer lead of the semiconductor device is electrically and mechanically connected to the land formed on the opening edge of the accommodation hole. Since the semiconductor device can be reliably held in the accommodation hole of the mounting board, the semiconductor device can be mounted on the mounting board without protruding from the upper surface of the main body, and each outer lead of the semiconductor device can be mounted on the mounting board. It can be electrically connected to the land as each contact.

(2) By mounting the semiconductor device on the mounting substrate without protruding from the upper surface of the main body, the thickness after mounting can be reduced, and after mounting, the electrical wiring is screened on the upper surface of the mounting substrate main body. It can also be formed by an appropriate thick film forming technique such as a printing method.

(3) Since the outer lead of the semiconductor device is formed to have a small radial length, the area occupied by the semiconductor device on the mounting substrate can be suppressed to a small value, so that the mounting density can be further increased. .

Although the invention made by the present inventor has been specifically described based on the embodiments, the present invention is not limited to the embodiments and various modifications can be made without departing from the scope of the invention. Needless to say.

For example, the semiconductor device 15 is not limited to being mounted on the mounting board while being housed in the housing hole of the mounting board.
It may be mounted on the mounting surface of the mounting substrate 22A as shown in FIG. Even when the semiconductor device 15 is mounted on the mounting surface of the mounting board 22A in this manner, the radial length of the outer lead 8 is short, and therefore the mounting board 22A is mounted.
The area occupied by the semiconductor device 15 in the above can be sufficiently suppressed, and the packaging density can be increased.

Further, as shown in FIG. 7, a heat sink 16 is provided on the main surface of the tab member 10 to which the pellets 12 are bonded, opposite to the main surface of the pellet bonding main surface.
May be fixed. In the semiconductor device 15A having this heat sink 16, the heat generated in the pellet 12 can be radiated to the outside of the resin-sealed package 14 through the heat sink 16 very effectively, so that the heat radiation performance of the semiconductor device 15A can be improved.

In the above-described embodiment, the case where the outer leads are configured so as to project from the resin-sealed package in four directions has been described. However, the present invention is not limited to this, and the outer leads may be projected in two directions from the resin-sealed package. You may comprise.

Further, the pellet is not limited to be bonded to the tab member attached to the inner lead, and may be configured to be pellet-bonded to the tab suspended in advance on the lead frame.

In the above-described embodiment, the case where the mounting substrate is provided with the accommodation hole has been described. However, the accommodation recess for accommodating the semiconductor device is a through hole formed so as to penetrate through the mounting substrate in the thickness direction. However, the hole may have a bottom.

In the above description, the case where the invention made by the present inventor is mainly applied to the semiconductor integrated circuit device which is the background field of application has been described, but the present invention is not limited thereto and the resin-sealed package is used. The present invention can be applied to a semiconductor device such as a transistor and a hybrid IC, and a general mounting technique on a mounting substrate. In particular, the present invention can be used in cases where high density and thin mounting is required, and excellent effects can be obtained.

[0060]

The effects obtained by the typical ones of the inventions disclosed in the present application will be briefly described as follows.

A housing recess is formed in the mounting substrate body, the semiconductor device is inserted into the housing recess, and the outer leads of the semiconductor device are electrically and mechanically connected to the contacts formed on the opening edge of the housing recess. Since the semiconductor device can be electrically connected to each contact in the accommodation recess of the mounting substrate, the semiconductor device can be mounted on the mounting substrate without protruding from the upper surface of the main body. The thickness of the body can be reduced.

Since the outer lead of the semiconductor device is formed to have a small radial length, the area occupied by the outer lead on the mounting substrate can be suppressed to a small value.
The mounting density can be further increased.

[Brief description of drawings]

1A and 1B show a mounting structure of a semiconductor device according to an embodiment of the present invention, in which FIG. 1A is a front sectional view and FIG.

FIG. 2 shows the mounting board used for it,
(A) is a perspective view, (b) is sectional drawing which follows the bb line | wire of (a).

3A and 3B show a multiple lead frame used for manufacturing a semiconductor device according to an embodiment of the present invention, in which FIG. 3A is a partially omitted plan view and FIG. 3B is a front sectional view.

4A and 4B show a state after pellet and wire bonding, FIG. 4A is a partially omitted enlarged partial plan view, and FIG. 4B is a front sectional view.

FIG. 5 is a vertical cross-sectional view showing a molding process of a resin-sealed package.

6A and 6B show another mounting example of the semiconductor device which is an embodiment of the present invention, in which FIG. 6A is a front sectional view and FIG.

7A and 7B show a semiconductor device according to another embodiment of the present invention, FIG. 7A is a front sectional view, FIG. 7B is a half plan view, and the other half is a bottom view.

[Explanation of symbols]

1 ... Multiple lead frame, 2 ... Unit lead frame, 3
Outer frame, 4 ... Section frame, 5 ... Dam suspension member, 6 ... Dam member, 6a ... Dam, 7 ... Inner lead, 8 ... Outer lead, 9 ... Tab member mounting portion, 10 ... Tab member, 11 ... Pellet bonding layer , 12 ... Pellet, 13 ... Bonding wire, 14 ... Resin-sealed package, 15 ... Semiconductor device, 15A ... Semiconductor device with heat sink, 16 ...
Heat sink, 21 ... Semiconductor device mounting structure, 22 ...
Mounting board, 23 ... Mounting board body, 24 ... Housing hole (housing recess), 25 ... Land (contact), 26 ... Electrical wiring,
27 ... Solder layer, 50 ... Transfer molding device, 5
1 ... Upper mold, 52 ... Lower mold, 53 ... Cavity, 54 ... Pot, 55 ... Plunger, 56 ... Cull, 57 ... Runner,
58 ... Gate, 59 ... Lead frame escape recess, 60 ...
Resin (resin, molding material).

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Kazuya Takahashi, Kazuya Takahashi, 5-20-1 Kamimizuhonmachi, Kodaira-shi, Tokyo, Ltd., Semiconductor Company, Hitachi Ltd. (72) Inventor, Tadada Sakuraba Kodaira, Kodaira-shi, Tokyo 5-20-1 Honmachi, Hitachi Ltd. Semiconductor Division

Claims (3)

[Claims] 1. A mounting board in which a housing recess is formed in a main body, and a contact is arranged at an opening edge portion of the housing recess in one main surface of the main body, and a housing recess housed in the mounting board. And a semiconductor device in which an outer lead is provided so as to protrude from the one main surface side end portion of the outer peripheral surface of the package so as to face the contact, and the semiconductor device is the mounting substrate. A mounting structure for a semiconductor device, wherein the package is housed so as to be entirely immersed in the housing recess, and the outer lead is mounted in a state of being electrically connected to the contact. 2. A mounting board, characterized in that a storage recess is formed in the main body, and a contact is disposed on an opening edge portion of the storage recess on one main surface of the main body. 3. A pellet having an electronic circuit built therein, a plurality of inner leads and outer leads for taking out the electronic circuit of the pellet to the outside, and a resin-sealed package for sealing the pellet and each inner lead with a resin. In a semiconductor device provided with, outer leads are provided so as to project outward in the radial direction on one main surface side end portion of the outer peripheral surface of the resin-sealed package, and the outer leads are formed to have a short radial length. The semiconductor device according to claim 1, wherein the semiconductor device comprises: