JPH06268105A - Structure for part package and manufacture of electronic circuit using part package - Google Patents

Abstract

PURPOSE:To provide a structure for part packages which is suitable for high- density mounting and can be easily tested in a mounting state and to which wiring can be quickly and easily added in the mounting state. CONSTITUTION:The lower end sections and their vicinities of lead frames 3 molded in a party package 1 are formed in part pins 2 and the upper end sections of the frames 3 are exposed from the top surface of the package 1 and respectively form pads 4. When such a constitution is used, tests can be easily performed by bringing tester pins into contact with the pads 4 even after the package 1 is mounted on a substrate. In addition, the soldering work for adding wiring to the pads 4 can be quickly and easily performed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a structure of a package of a component containing an electronic circuit and a method of manufacturing an electronic circuit using the package, and in particular, the component is mounted on a printed circuit board at a high density. In this case, the present invention relates to a technique for facilitating a test of the printed circuit board and a wiring change when a design change occurs and a technique for facilitating a test of an external component unit.

[0002]

2. Description of the Related Art The structure of a package of a conventional electronic circuit component is as shown in Japanese Patent Laid-Open No. 4-145683. In order to mount the electronic circuit component on a printed circuit board,
It is set with the lead frame facing the board. Further, as described in Japanese Utility Model Laid-Open No. 4-59973, the lead frame is formed in a flat plate shape, and no consideration is given to the test of individual components, the test when mounted on a printed circuit board, and the design change. It was

There is also a type in which a test pad is provided at the tip of a component lead frame, but this method is the same as forming a pad on a printed circuit board, so that the component mounting area is increased and high density mounting is performed. It was inconvenient for the printed circuit board.

[0004]

When it is confirmed that the conventional printed circuit board is manufactured correctly according to the circuit design, an in-circuit tester is used to bring the tester pin into contact with the component pin and supply a test signal to the result. Similarly, it was confirmed from the tester pin that was in contact with the component pin.

However, with the recent miniaturization and higher performance of devices, the logical scale of one printed circuit board has been dramatically increased in order to reduce the number of printed circuit boards used. For this reason, the components mounted on the printed circuit board are also becoming smaller and higher in density, and recently, imposition components having a component pin spacing of 0.3 mm have also appeared. When many such components are mounted on the printed circuit board, the conventional in-circuit test method for ensuring the manufacturing quality cannot be applied. This is because when the surface-mounted parts are connected to each other, when the tester pins are brought into contact with the component pins, the printed circuit board and the component pins are in an open failure state due to the solder float, and the tester pins are pressed into conduction. This is because it becomes a condition and misses the failure.

Further, when the size of the component pin becomes small and the pin interval becomes small, it becomes impossible to physically contact the tester pin with the component pin. In order to avoid this, a test-dedicated contact point called a test pad is also installed on the printed circuit board. However, this method requires an extra area on the printed circuit board for the test pad, which results in high-density mounting. It was inconvenient to do.

For the same reason, a design change occurs in a printed circuit board on which components having minute component pin intervals are mounted at a high density, and it becomes necessary to cut a printed pattern, or a jumper wire is added to the printed circuit board. When it is necessary to solder the printed pattern, it is extremely difficult to solder the jumper wire to the component pin because the pin interval is small even if the print pattern can be cut. Therefore, there is a problem that the design cannot be changed after the printed circuit board is manufactured.

[0008]

In order to carry out the manufacturing test of the high-density printed circuit board as described above, a pad for connecting the lead frame of the component pin with the same potential is provided on the upper surface of the component package mounted on the printed circuit board. This allows testing by contacting the pads on the component package without directly contacting the component pins.

Also, when connecting jumper wires between component pins due to design changes or the like, the design can be easily changed by connecting the wires to pads provided on the upper surface of the component package.

[0010]

The pad provided on the upper surface of the component package can transmit the signal received from the signal propagation medium contacting the pad from the outside of the component to the component pin of the component. Further, this signal can be simultaneously propagated to the electronic circuit in the external component package.

If a reference point is set on the upper surface of the component package, it can be used as a reference point for accurately obtaining the pad position on the component package when the operation of the tester pin is controlled by NC control.

When a hole is formed on the upper surface of the component package for connection with the lead frame, a conductor (for example, a tester pin) for contacting the component pin from outside is brought into contact with the hole corresponding to the specific component pin. If you try
Positioning can be easily performed, and there is a function of preventing the conductor from shifting after coming into contact with the pin position of the external component.

If a recess is formed in the center of the pad provided on the upper surface of the component package, it functions to prevent the conductor contacting the pad from shifting. Further, when soldering the conductor, it also has a function of improving the placement of the solder.

If a bulge is formed in the lead frame inside the component package, it serves to widen the contact point with the space vacated on the upper surface of the package and improve the contact with the conductor contacting through the space. .

When a conductor is embedded in a space for contacting the conductor, which is vacated above the component package, it has a function of blocking moisture penetrating from the space vacated in the component package to the inside and is contacted from the outside. It has the function of protecting the lead frame from the conductor.

If a crack is formed in the lead frame in the portion exposed outside the component package, it works to facilitate the process when the pad and the component pin on the upper part of the component package are vertically separated.

When the upper surface of the component package is expanded, the pad area on the upper surface of the component package can be expanded without changing the mounting area on the printed circuit board, and the gap between the pads can be widened, so that the conductor can be easily contacted. Has a function to

[0018]

Embodiments of the present invention will be described with reference to the drawings.

FIG. 1A shows an embodiment in which pads for connecting to component pins are provided on the upper surface of the component package. In FIG. 1A, a component pin 2 is provided on a side surface of a component package 1, and a lead frame 3 connected to the component pin 2 advances from a component pin 2 to a side surface of the component package 1 and on a top surface 5 of the component package 1. The pad 4 is formed. In the figure, 1a indicates a reference point of the pad coordinate position.

FIG. 1B is a sectional view of a component of the embodiment shown in FIG. 1A, in which 2b represents an LSI chip and 2a represents a bonding wire.

FIG. 2 is a perspective view showing a state in which a plurality of component packages according to the present invention are mounted on the printed board 7 and the connection relationship between them is tested. In the figure, 20, 21 and 22 are parts according to the present invention, 9 is a tester pin for observing a signal from the tester 11, and 10 is a test terminal for supplying a test signal. When confirming the connection of the print pattern 8 between the components 21 and 22 on the printed circuit board 7, the observation tester pin 9 is brought into contact with the pad 211 on the component 21 and the pad 221 on the component 22 is used for signal supply. The tester pin 10 is brought into contact and a test signal is supplied. By observing this signal at the test terminal 9, it can be confirmed whether or not the print pattern 8 and the component pins 213 and 222 are properly connected.

An embodiment when a design change occurs will be described with reference to FIG.

In the figure, parts 20 and 21 are parts according to the present invention. When the pins of these parts must be connected by a design change, both ends of the jumper wire 12 are connected to the pad 212 of the part 21 and the part 20, respectively. Soldering to the pad 23 allows quick and easy connection.

FIG. 3A shows an embodiment in which the pad area is created by expanding the upper surface of the component when the shape of the component is small and the pad cannot be provided on the upper surface of the component.
FIG. 3B is a sectional view of the embodiment shown in FIG. Pads 4a in the figure show pads arranged in the expanded region, and pads 4b show pads arranged inside thereof.

FIG. 4 shows an example of the lead frame when the pads are three-dimensionally formed. In this example, a portion of the lead frame 41 is formed so as to project onto the upper surface of the component package so that a jumper wire can be wound.

FIG. 5A shows a sectional view of an embodiment different from the above. In this figure, a pad 70 is installed from the upper surface of the component package 1 to the inside of the component package 1 on the lead frame 2, and a conical window 73 is opened to make contact with this point. The conductor 71 for the purpose is embedded. The lead frame 2 has a bonding pad 2a and an LSI chip 2b.
The signal of the lead frame 2 can be propagated to the LSI.

A plan view of the component package of the embodiment shown in FIG. 5A is shown in FIG. 5B. FIG. 6A is a plan view of a lead frame used in the component package 1 of FIG. A bulge in the middle of the lead frame 80 (wide part)
Reference numeral 70 denotes a portion that comes into contact with the conductor 71 embedded in the window 73 opened on the upper surface of the component package.

FIG. 6B shows a state before processing the lead frame. Connection point 104 with bonding pad
The part is thin and the pad part 100 and the part pin 102 which are exposed on the upper surface of the part package are separated at a bending point 101. Further, the pad 100 is provided with a recess 103 in the center thereof. Figure 6
FIG. 6C is a diagram after the lead frame of FIG. 6B is molded.

FIG. 7 is a plan view showing an example in which the shape of the pad 121 arranged at the corner 120 of the component package is different from the shape of the pad 122 arranged other than the corner, and the top surface of the package is effectively used. Such a configuration is effective when the number of leads is large compared to the top area of the package and therefore the number of pads is large.

[0030]

The component package according to the present invention can be tested in a manufacturing test of a high-density printed circuit board on which the component package is mounted without incorporating a test-dedicated circuit inside the electronic circuit. Therefore, the overhead of the electronic circuit due to the test-dedicated circuit is eliminated, and it is not necessary to create a test pattern for the test-dedicated circuit. Furthermore, since the test method is only the continuity test, it is not necessary to use a high-performance tester for driving an electronic circuit, so that it is possible to perform the test using an inexpensive and simple tester.

Further, since it is not necessary to directly contact the component pins at the time of the test, the open failure due to the component pin contact is not overlooked.

In high density mounting of the printed circuit board, it is not necessary to provide a test pad or a changing pad on the printed circuit board, so that the mounting area can be effectively used and the design of the high density mounted printed circuit board is facilitated. There is.

[Brief description of drawings]

1 shows an embodiment of the present invention, (A) is an external view of a component package, and (B) is a sectional view of the embodiment.

FIG. 2 is an external view of a component package according to the present invention mounted on a printed circuit board.

3A is an external view of a component to which a component package showing an embodiment different from the above is applied, and FIG. 3B is a sectional view thereof.

FIG. 4 is an external view showing a lead frame shape of an embodiment different from the above.

5A is a cross-sectional view of a component package showing an embodiment different from the above, and FIG. 5B is a plan view thereof.

FIG. 6A is a plan view showing an example of a lead frame which comes in contact with the window of the component package, FIGS. 6B and 6C show an example of a lead frame different from the above, and FIG. The front perspective view, (C) is a perspective view after the molding process.

FIG. 7 is a plan view of an embodiment different from the above.

[Explanation of symbols]

1 ... Component package, 1a ... Pad reference point, 2 ... Component pin, 2a ... Bonding wire, 2b ... LSI chip, 3 ... Lead frame, 4 ... Pad.

Claims (10)

[Claims] 1. A component package including an electronic circuit and a lead frame connected to the electronic circuit, wherein a pad is formed by exposing a part of the lead frame on an upper surface of the component package. Package structure. 2. The structure of a component package according to claim 1, wherein a central portion of the pad exposed on the upper surface of the component package is recessed. 3. A structure of a component package, characterized in that a top surface of a pad exposed and formed on an upper surface of the component package of claim 1 is made flat. 4. The structure of a component package according to claim 1, wherein a pad exposed and formed on the upper surface of the component package is projected from the top surface of the component package. 5. The structure of a component package according to claim 1, wherein the pad formed by being exposed on the upper surface of the component package has the same potential as a terminal and a lead frame of an electronic circuit in the component package. 6. The structure of the component package according to claim 1, wherein a space directly contacting from the outside of the component package is provided in a part of a lead frame connected to an electronic circuit inside the component package. . 7. The component package according to claim 6, wherein a space in contact with the internal lead frame is provided on the upper surface of the component package, and the upper surface of the shape of the space is larger than the bottom surface and becomes narrower toward the inside of the package. Characteristic parts package structure. 8. The component package according to claim 1, wherein the upper surface of the component package is larger than the lower surface. 9. The component package according to claim 1, wherein pads that are connected to the same potential as the component pins are exposed and arranged on the upper surface of the component package, and a reference point is provided on the upper surface of the component package. The structure of the component package is characterized in that the positional relationship of the pads can be accurately determined. 10. A method of manufacturing an electronic circuit comprising a group of components having a pad connected to the same potential as a component pin on the upper surface of the component package, and a conductor electrically connecting the components to each other. A method for manufacturing an electronic circuit using a component package, characterized in that a conductive wire is connected to the pad corresponding to the component pin to add wiring for connecting the component pins after the electronic circuit is manufactured.