JPS5925386B2 - Mounting body and mounting method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Electronic devices such as radios, televisions, and video tape recorders are becoming smaller and thinner.

For this reason, the electronic components that make up these electronic devices, for example, in the case of resistors, have changed from solid resistors with lead wires at both ends to chip resistors, in which a resistor layer is printed on a ceramic substrate several nanometers square. It was. Furthermore, capacitors also changed to chip capacitors, which were made by laminating electrolytic layers several square meters in size. Also, in the packaging of engineering C, flat pack type packages, which are thinner and smaller, have come to be used instead of DIL type packages. Electronic devices are gradually becoming smaller and thinner through mounting using these smaller and thinner electronic components, but as the number of ICs mounted has increased in recent years, the method of mounting the ICs has become problematic. has been looked at.

The IC itself has circuit functions built into a Si chip using semiconductor technology, and the size of the Si chip is the actual size of the IC. The size of this IC (for example, a Si chip) makes it extremely difficult to handle when mounted on a printed circuit board, etc., so the electrode terminals provided on the Si chip were enlarged to make it easier to handle.
L-shaped and flat pack types are used. However, for this reason, the mounting area becomes significantly larger than that of the Si chip. For example, in the case of a 5n LSI with about 60 pins, if it is packaged in a flat pack type, its mounting area will be 22 x 22n, which is about 20 times that of a Si chip. This results in an increase in the mounting area of the device. The present invention is based on I
The purpose is to mount electronic components such as Cl chip resistors and chip capacitors in a high density and thin manner.

FIG. 1 illustrates a conventional mounting method that is considered to have relatively high density.

In FIG. 1, the details will be mainly focused on the implementation of the IC. Thickness 1~
Au. A wiring body 2 of Ag or silver/palladium is formed (FIG. 1a).

Next, a Cu layer 3 is formed (FIG. 1b). The Cu layer 3 is formed to a thickness of several tens to several hundred micrometers by resistance heating, vacuum deposition such as sputtering, or electroplating. A pattern j having an arbitrary shape is formed on the Cu layer 3 by photoetching (FIG. 1c). Next, an IC having an electrode terminal 5
The chip 4 is fixed onto the ceramic substrate 1 with a conductive adhesive or the like (FIG. 1d). A polyimide resin layer 6 is provided on the ceramic substrate on which the Cu pattern 3' and the IC chip 4 are mounted (FIG. 1e). The polyimide resin layer 6 can be formed by heating and pressurizing a polyimide resin film thicker than the 1C chip from above the 1C chip to obtain the structure shown in FIG. The resin may be formed by spin coating. Next, holes are opened in the polyimide resin 6 on the electrode terminal 5 of the 1C chip 4 and on the Cu pattern j to form openings 7 and 8 (FIG. 1f).

The openings 7 and 8 can be formed by applying a photosensitive resin onto the polyimide resin 6 and performing photoetching. A Cr/Cu film is deposited by vapor deposition on the surface where the openings 7 and 8 are formed, and a wiring pattern 9 is formed by photoetching to connect the openings 7 and 8. Obtain the structure shown in Figure 1g.

In the mounting method using the manufacturing method shown in FIG. 1, since the IC chip is mounted in the chip state, high-density mounting can be achieved, but it has the following drawbacks.

In the unlikely event that the IC chip is defective, the 1C chip cannot be replaced.

2. The number of process steps required to obtain the structure shown in FIG. 1g is too large, resulting in a low yield.

3. Furthermore, since the thickness of the ceramic substrate is required, the thickness of the mounted body increases.

The present invention aims to eliminate these conventional drawbacks.

The invention is explained in detail in FIG. For example, a plurality of openings 12 are formed in advance in a long polyimide resin film 11 having a width of 35 m1L (FIG. 2a). The thickness of the polyimide resin film 11 is approximately 125 μm, and the openings 12 are for inserting electronic components such as ICs, chip resistors, and chip capacitors. Next, a 35 μm thick Cu foil 13 was pasted (Fig. 2b),
Cu lead wires 13/ that protrude into the plurality of openings 12 and selectively connect between the plurality of openings 12 are formed by photolithography (FIG. 2c). The Cu lead wiring 13' is formed in a portion corresponding to an electrode terminal of an IC or chip component, which will be described later. A Ni plate (thickness 0.1 to 0.0
．． 2 μm) 14 is pasted onto the polyimide resin film 11 using an adhesive 15 (FIG. 2d). Next, solder bumps 16 are formed on the electrode terminals of the chip component 17, and the solder bumps 16 are inserted into the openings 12, and the heating jig 20 is
By heating to 0 to 400 DEG C. and applying pressure 21 from above the Cu lead wiring 1S, the electrode terminals of the chip component 17 are soldered and fixed to the Cu lead wiring. In the case of 1C18, solder bumps 19 or Au bumps are similarly formed on the electrode terminals, aligned with the Cu lead wiring 131, and heated and pressurized 217 using a heating jig 2σ to form the IC electrodes. The terminal can be connected by soldering to the Cu lead wiring 13' or by applying Sn plating to the α lead wiring 13' to form an Au-Sn eutectic (see Fig. 2). e). Finally, a protective film 22, 2 made of epoxy resin or silicone resin is applied and cured to obtain the structure shown in FIG. 2f.

Furthermore, in the case of the present invention, crossover wiring can be implemented using the above-mentioned Ni board.

This will be explained in FIG. Polyimide resin film 1
1 is opened to expose the Nl plate 14/, and the Cu lead wirings 231 and 23! ' and the exposed Ni plate 147
If the Ni plate 14' is soldered and fixed to the top, the 0
1 lead wires 23' and 23'' can be connected.
In FIG. 3, on the Ni plate 14', a wiring 131 that intersects with the Cu lead wirings 231, 23'' is formed on the polyimide resin film 1''. In the present invention,
Polyimide has been used as the resin film, but films of polyethylene, polyester, artificial mylar, etc. may also be used, and the Ni plate may be a Fe plate, Bs plate, etc. as long as it has conductivity and mechanical strength. , is not limited to Ni plates.

FIG. 4 is a plan view of FIG. 2.

An IC is placed on the polyimide resin film 11 in advance.
It has an opening 12 for inserting a tip 18 and a chip part 17.

On the polyimide resin film 11, CuI]-
A field wiring 13' is formed. The Cu lead wiring 13'
is a structure in which the wiring extends to a position corresponding to the electrode terminal of the Cl 8 or chip component 17 inserted in the opening 12, and furthermore, a structure that crosses the opening 12, such as the Cu lead wiring 13. It is formed in The Cu lead wire extending into the opening 12 is connected to the bump 19 on the electrode terminal of the ICl 8 and the bump 16 on the electrode terminal of the chip component 17. Further, on the opposite side of the polyimide resin film 11 on which the Cu lead wiring 13' is not formed, a Ni film is formed, which integrally has a base for increasing mechanical strength and a terminal for connecting the constructed circuit to an external circuit.
A board 14 is attached.

The Ni plate has an opening having approximately the same size as the opening 12 of the polyimide resin film 11, and has an external terminal 35 for connection to an external circuit. The existing Cu lead wiring 13'7 is fixed by soldering. A dotted line 36 indicates the position where the unnecessary portion of the Ni plate 14 is cut. The external terminal 35 is adhesively fixed to the polyimide resin film 11. As a more effective manufacturing method of the present invention, for example, as shown in FIG. 5, Cu lead wiring 13' extending into the opening 12 of the polyimide resin film 11 is bent.
In order to prevent accidents such as not being able to connect with the bumps of IC or chip parts, as shown in Figure 6,
By placing about 11 insulating plates 35 on the lead wiring 13' and fixing them with adhesive 36, the above-mentioned accident can be prevented.

FIG. 7 shows a cross-sectional view of the chip parts soldered. Next, an outline of mass production of the embodiment of the present invention shown in FIG. 2 will be explained with reference to FIG. 8.

The polyimide resin film 51 with feeding holes 50 formed in advance is moved to step 15 by the guide roller 52.
3, the punching machine 5 forms the desired shape.
4 opens an opening 5 for inserting IC and chip components.
form 5. In the next step 56, for example, 35μ
A Cu foil 57 coated with m-thick adhesive is placed on a guide roller 58.
and 59 to bond it to the polyimide resin film 51. In step 60, the photosensitive resin 61 is dropped from the nozzle 62 onto the adjacent guide rollers 63, 63' to coat the Cu foil 57 to a certain thickness, and the photosensitive resin film is exposed to an infrared lamp using the stepper 64. Dry at 65°C. Step V66 is a mask exposure process in which a mask 68 having a pattern 67 for forming Cu lead wiring is adhered onto the polyimide resin film 51 coated with the photosensitive resin, and ultraviolet light 70 is irradiated with an ultraviolet lamp 69. irradiate. The polyimide resin film 51 having the exposed photosensitive resin film is sent to step 72 by the guide roller 71 . The polyimide resin film 51 passes through a tank 74 filled with a developer 73 to reveal a Cu lead wiring pattern 75 made of photosensitive resin, and in step 76, the photosensitive resin pattern 75 swelled by development is removed. harden it using an infrared lamp JMoV. Next, in step 78, the exposed Cu foil is etched away using the photosensitive resin pattern 75 as an etching mask. The etching liquid is sprayed from a nozzle 79. Ni plate 81 for reinforcement by step 80
are pressed together by guide rollers 82, 82' and bonded together with adhesive or the like.

The Ni plate 81 is a long plate, and is provided with an opening 55' into which a chip component provided on the polyimide resin film 51 is inserted, and an external terminal 83. Step X84 is a process of soldering the Cu lead wire 85 to the solder bump provided on the electrode terminal of the ICl chip component. IC86, chip resistor 87, chip capacitor 8
8 are mounted on dedicated trays 86/, 87/, and 881, respectively, and the trays 86', 87', and 88' are conveyed below the respective openings 55, and the heated jig 89 is lowered. , for soldering. C. The soldered chip components are transported to step 190,
It is cut into the final shape as shown in 92 by a punching machine 91 for die cutting. As described above, the configuration of the present invention allows a consistent mass production system to be configured. Next, the effects of the present invention will be described while explaining the effects of Examples.

The polyimide resin film, which is the main constituent material of the present invention, is 0.125 m11 The Ni plate for reinforcement is 0.1 to 0.3 m
Since the thickness of the substrate is 1L, the thickness of the substrate itself is approximately 0.
Since it is about 4 to 0.5 mm, it can be mounted thinly.

Furthermore, since the present invention is a process in which IC5 chip components are soldered after the process of wiring the board mainly consisting of the polyimide resin film and the Ni plate is completed, there is no difference between the good finished board wiring and the good ICl chip parts. Since this method connects the two, the yield is significantly higher than that of the conventional example.

If the bump material on the electrode terminal of the ICl chip component is made of solder, even if a defective 1C or chip component is installed, it can be easily attached and detached by heating it again with a heating jig and replaced with a good one. It is possible to configure a system such as

The present invention is a so-called parallel construction method in which the process of creating board wiring and the process of fixing chip components to the board wiring are performed in completely separate processes. In the example shown in Fig. 1, a chip component is placed on a board, covered with polyimide resin, holes are formed on the electrode terminals of the chip component, a metal film is deposited on the entire surface, and a wiring pattern is formed by photolithography. By forming
This is the so-called serial construction method. For example, the yield in the case of two processes (the yield of each process is 90 (
(assumed to be L), in the case of the serial construction method, it is 0.9
×0.9=0.81, resulting in a final yield of 81 (Ff), whereas in the case of parallel construction, 1-(0.1X0.1)20.99, the final yield is 99 (fl). . As described above, the configuration of the present invention can provide an extremely high yield. In the configuration of the conventional example shown in FIG. 1, if a defective IC or chip component is installed, it is not possible to remove and replace only the defective chip, because the 1C In order to replace the 1C and chip parts, it is necessary to excavate the 1C and chip parts from the polyimide resin.

As a result, the wiring patterns of ICs and chip components are completely damaged. Furthermore, even if it is possible to replace the ICl chip with a new ICl chip component, it is necessary to start from the initial embedding process with polyimide resin, so in most cases, even if one chip is defective, the entire board must be declared defective. Therefore, the manufacturing yield was significantly lowered and the manufacturing cost was significantly increased. However, with the manufacturing method of the present invention, by heating the joints on the chip parts and the leads again with a heating jig, the chips can be easily attached and detached and replaced with good products. Furthermore, when mounting an IC or the like on a substrate by a method other than the example shown in FIG. Said IC
Not only is a process necessary for bonding the leads extending from the electrode terminals of the chip to the wiring board, but also a bonding area is required for bonding the extended leads to the wiring board.

The need for this bonding area directly reduces the packaging density, making it impossible to perform high-density packaging. In contrast, in the present invention, only the electrode terminals on the IC chip and the leads need to be bonded, so the bonding area on the wiring board, which was conventionally required, is unnecessary, and high-density packaging is possible accordingly. It can be done. Generally, if the lead length is at least 27 nm, the junction area is required to be 2×(LSI chip peripheral length) 77ZJ. Furthermore, with the configuration of the present invention, since the metal film can be used as the external lead-out terminal (35 in Figure 4) of the component circuit, there is no need to add a new external lead-out terminal, so the number of man-hours is reduced and the cost is low. It is possible to provide an implementation.

[Brief explanation of drawings]

Figures 1a-g are explanatory diagrams of the conventional high-density mounting method;
Figures 2 a-f are cross-sectional explanatory views showing one embodiment of the present invention, Figure 3 is a cross-sectional view showing an application example of the present invention, Figure 4 is a plan view of an example of a finished product of the present invention, and Figure 5 6 and 7 are explanatory diagrams of application examples of the present invention, and FIGS. 8 a to 8 c are perspective views showing an example of the mass production process of the present invention.

Claims (1)

[Scope of Claims] 1. A metal frame having a plurality of first apertures, and a plurality of second apertures formed on the metal frame and matching with the plurality of first apertures. an insulating film,
a wiring pattern formed on the insulating film, having protrusions in the plurality of second openings and selectively connecting between the second openings; A mounting body including a plurality of element pieces inserted and arranged from the opening side and connected to the protrusion and electrodes. 2. A step of forming a plurality of openings in an insulating film, a step of adhering a metal film to the insulating film, etching the metal film, and forming protrusions in the plurality of openings while selectively processing a wiring pattern connecting the openings to the insulating film; bonding a metal frame having a plurality of openings that match the openings of the insulating film to the insulating film; and a plurality of the metal frames. a step of inserting a plurality of element pieces into the opening portion, inserting the protrusion and the plurality of element pieces, and joining the protrusion and the electrodes of the plurality of element pieces, the insulating film and the metal frame; A mounting method comprising the step of cutting the into a predetermined shape.