JP3609527B2 - Electronic equipment - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a structure of a lead terminal and a manufacturing method thereof in an electronic device in which a lead terminal is integrally molded with a resin case material or a frame.
[0002]
[Prior art]
In general, a hybrid integrated circuit device includes a substrate on which a semiconductor element or the like is fixed and achieves a predetermined circuit, and a frame that forms a box shape with the substrate, and resin is injected into the space forming the box. Further, the box itself is a case material, and the substrate is mounted in the box and resin is injected.
[0003]
For example, Japanese Patent Publication No. 06-0666408 is an example, and FIG. Here, a box-shaped case material is used for the description.
First, there is a substrate 1 having at least an insulating surface. This substrate may be based on an insulating material such as a ceramic, a printed circuit board, or a glass substrate, or may be based on a metal material such as aluminum or Cu. In the case of a metal material, an insulating resin is coated on the surface in order to provide insulation.
[0004]
In any case, the surface has an insulating property, and the wiring 2, land, bonding pad 3 and the like are realized thereon by a copper foil patterning process or the like.
On the other hand, the box-shaped case material 4 is molded with polyimide, epoxy resin, or the like, but a lead terminal 5 made of metal is integrally molded with the case material 4 in order to realize connection with an external circuit. .
[0005]
The case material 4 shown in FIG. 5 shows a portion where the lead terminal 5 is molded, and the portion bonded and fixed to the substrate is also the periphery of the substrate or may be provided inside the substrate. . In either case, the bonding pad 3 and the lead terminal 5 are arranged close to each other, and the two are connected by a thin metal wire 6.
[0006]
[Problems to be solved by the invention]
In FIG. 5, vibration is generally applied to the wire bonding. This is especially the case with fine metal wires made of aluminum. That is, as shown in FIG. 3, when the energy applied to the bonding tool is the vertical axis (power) and the horizontal axis is time (Time), the bonding tool is positioned on the bonding pad 3 with a predetermined power. After pressing the metal thin wire 6 and confirming that it was attached, the power was lowered and pressed for a predetermined time to complete the bonding.
[0007]
For example, the impedance of the bonding tool is measured and the power is lowered when a certain value is reached.
However, the lead terminal of FIG. 5 has upper and lower natural frequencies as indicated by arrows, and when the natural frequency of the lead terminal 5 and the vibration frequency of the bonding tool match, they rise and fall at the same wavelength. However, the fine metal wire and the lead terminal are not fixed (bonded). Therefore, the impedance does not decrease, and it keeps pressing at the highest power as shown by the dotted line, so the crushed Al part (flat part) is not attached or attached, but it is impossible to mold the wire. In addition, there is a problem that the neck portion becomes weak and the neck portion breaks.
[0008]
For example, referring to FIG. 4, when AHz vibration is applied to the bonding tool 10 and this vibration is applied to the fine metal wire 6 for wire bonding, the lead terminal 3 has a natural frequency BHz, and the fine metal wire as it goes to the right. Since C is fixed, the frequency decreases to CHz and DHz. Therefore, if the frequency of both is compared, it can confirm that the metal fine wire was attached. This is realized by the software attached to the wire bonding device. The frequency of the bonding tool and the lead terminal is compared, and if it seems to resonate, the frequency is shifted and the appropriate point is searched for connection. ing. Therefore, there is a problem that an expensive software-equipped device is required, or depending on the software, an appropriate resonance point cannot be found, and pressing continues with high power.
[0009]
[Means for Solving the Problems]
The present invention has been made in view of the above-described problems. The lower layer of the bonding area of the lead terminal extends substantially vertically to the substrate with a support unit integrated with the frame, and the vertical vibration of the lead terminal in the bonding area is stopped. This is solved by having a stopper portion. That is, the stopper portion can substantially eliminate the natural vibration of the lead terminal, and the power of the bonding tool can be applied efficiently. Therefore, both of them do not resonate, and impedance reduction occurs in a predetermined time, and even if the device detects the completion of bonding by comparing the frequency of the lead terminal and the bonding tool, it can continue to apply more power. Because there is not, unreasonable wire molding is not added.
[0010]
If the cross-sectional shape of the lead terminal is an inverted T type, the upper surface is exposed and the periphery thereof is molded with a support portion made of an insulating resin, the horizontal bar of the reverse T is held by the resin support portion to prevent vertical vibration. be able to.
Further, the problem is solved by forming the lead terminal into a bowl shape whose section is rotated by 90 degrees, exposing the upper surface, and molding the periphery with a support portion made of an insulating resin.
[0011]
Further the lead terminals, and the cross section rectangular shape type, the support portion made of an insulating resin, solves in that it covers the sides near the lead terminals top to expose the lead terminals top other than this.
In order to prevent vertical vibration of these three lead terminals, the inverted T type is the stopper part at the lower horizontal bar, and the vertical type is the stopper part where the C-shaped part is inclined. Furthermore, since a part of the rectangular shape is covered with resin, the vicinity of both sides in the longitudinal direction becomes a stopper portion.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an embodiment of the present invention will be described with reference to FIG.
In the present invention, the lead terminal structure that suppresses vertical vibration is the point of the present application, and the substrate is an insulating substrate such as ceramic, glass and printed circuit board, and the surface is insulated with a metal substrate such as Al, Cu and Fe. Any of these may be used, and a hybrid integrated circuit board is generally used.
[0013]
First, the hybrid integrated circuit board will be described. In other words, the hybrid integrated circuit board 1 that has been subjected to insulation treatment has conductive means formed on the surface. As the conductive means, a wiring pattern 2, a land, a pad (connection portion with an external lead), a bonding pad (bonding area), and the like can be considered. A semiconductor chip or a semiconductor IC is soldered to the land, and a resistor or the like is fixed to the wiring pattern by printing, and a chip resistor or a chip capacitor as a component is fixed by solder. Here, it is omitted for the convenience of the drawing.
[0014]
The hybrid integrated circuit board 1 employs an Al metal substrate having an anodized surface and aluminum oxide deposited thereon, and the conductive means is deposited by hot pressing through an adhesive resin layer such as polyimide. .
Naturally, the semiconductor element is mainly a bare chip, and is a diode chip, a transistor chip, an LSI chip, or the like, and other components such as a chip resistor, a transformer, and a chip capacitor are mounted on the hybrid integrated circuit board as necessary.
[0015]
In the chip and the conductive path (bonding area), a thin metal wire is wire-bonded as necessary to achieve a predetermined circuit.
In addition, the connection to the external circuit is such that one element lead terminal forming the connector is integrally molded with the case material, and the external lead is connected to the pad provided on the side of the hybrid integrated circuit board 1 by soldering. There are things that have been.
[0016]
The case material 4 is fixed to the periphery of the hybrid integrated circuit board 1 and has a box shape, or originally has a box shape and is fixed to at least a part of the inside of the box. In any case, a box-shaped space is provided, and an insulating resin is injected into the space for the purpose of passivation.
Reference numeral 4 shown in FIG. 1 is a support portion integrated with the case material, and the lead terminals are incorporated together during integral molding. The left end of the lead terminal 5 is connected to a bonding pad 3 provided in the vicinity thereof through a fine metal wire. On the other hand, the right end portion via the support portion extends outside the case and extends as an electrode of the connector. The connector is parallel to or perpendicular to the extending surface of the hybrid integrated circuit board. Therefore, in this case, the portion to be the support member is the same as the case material fixed to the periphery of the hybrid integrated circuit board 1. On the other hand, the support portion may be inside the hybrid integrated circuit board 1. In this case, the hybrid integrated circuit board is naturally extended from the case material fixed to the periphery of the hybrid integrated circuit board. Since there is a lead terminal inside the connector, the connector made of this is formed upward with respect to the hybrid integrated circuit board. The case material integrated with the support portion is fixed to the contact surface with the hybrid integrated circuit board via an adhesive. However, a metal, for example, Cu may be provided on the contact surface, and a Cu pattern may be provided on the hybrid integrated circuit board corresponding to the metal, and fixed through solder.
[0017]
The feature of the present invention resides in this lead terminal 5. That is, the stopper portion is provided so as to substantially eliminate the vertical vibration of the lead terminal. That is, FIG. 1 shows three types of lead terminals. By adopting one of these, vertical vibration is eliminated.
As described in the conventional example, if only the bottom and side surfaces of the lead terminal are in contact with the support portion as shown in FIG. 5, there is room for vibration upward as indicated by an arrow. That is, when vibration is applied from above with the bonding tool, the lead terminal also vibrates, and when both resonate (in short, resonating at the same frequency), the fine metal wire does not attach to the lead terminal.
[0018]
That is, in order to suppress the vertical vibration of the lead terminal, a stopper portion is provided on the lead terminal and the vertical vibration of the lead terminal is suppressed, whereby the fine metal wire and the lead terminal are fixed. That is, both are always fixed and the impedance is lowered, so that the solid line in FIG. 3 can be obtained. In other words, it is not necessary to keep pressing the bonding tool with much higher power.
[0019]
First, in the inverted T-shaped lead terminal on the left side, the horizontal bar 30 serves as a vertical vibration stopper. The resin is molded so that the upper surface 31 is exposed. Therefore, the lead terminal can be wire bonded without vertical vibration. The middle one has a rectangular cross section, and the upper surface near the side extending in the longitudinal direction is covered with resin. This portion serves as a vertical vibration stopper portion, and the exposed surface excluding this portion serves as a bonding area. Further, the right lead terminal has a hook-shaped cross section, and the inclined portion 32 extending downward with respect to the upper face of the hook has an angle Θ indicated by an arrow exceeding 90 degrees. This inclined part becomes a stopper part.
[0020]
FIG. 2 shows another embodiment. In this case, the support portion 4 is formed separately from the case material 33 and is molded together when the case material 33 is molded. The lead terminal is an inverted T type, but other lead terminals may be used. Also in this case, the vertical vibration of the lead terminal can be suppressed, and the fine metal wire can be bonded efficiently.
Returning to FIG. 1, since the lead terminal goes out and becomes a connector, it may be thinned as shown by reference numeral 34 or may be processed into a clip terminal shape sandwiching the substrate. In that case, in the case of the inverted T type, it is formed by drawing, so it is difficult to easily make it 34 or a clip shape, but the center and the right side can be easily formed by originally processing a thin plate with a press or the like. Moreover, vertical vibrations can be suppressed.
[0021]
Although not described in the drawings, a lead terminal having a stopper portion will be described with reference to FIG. That is, the lead terminal 5 is mounted on the support portion as shown in the figure, but is embedded up to the surface of the lead, but the tip of the lead (the front end portion in the drawing) is bent downward 180 degrees. It is just like a hook that catches things, and the bent part is embedded. Here, since the bent portion is embedded in the resin of the support portion, vertical vibration can be suppressed.
[0022]
【The invention's effect】
As is clear from the above description, vertical vibrations of the lead terminal can be suppressed by processing the lead terminal or by a resin molding method. In other words, the fine metal wire subjected to the vibration of the bonding tool and the lead terminal whose vertical vibration is suppressed do not resonate, so the fine metal wire and the lead terminal are connected, and there is always a decrease in impedance due to the bonding tool. Can be bonded without adding maximum power. Therefore, the thin metal wire is flattened into a corner and the neck is not cut off, so that the yield of bonding can be improved.
[0023]
If the cross-section of the lead terminal is inverted T-shaped, or if it is a saddle shape rotated 90 degrees, the lead terminal itself suppresses the vertical vibration of the lead terminal, and the connection between the fine metal wire and the lead terminal is ensured. Can be done.
Further, even when the lead terminal itself has an elongated shape obtained by pressing a flat plate and has a rectangular cross section, vertical vibration can be suppressed by wrapping the resin of the support portion to the surface.
[0024]
Particularly, a lead terminal having a saddle shape or a rectangular cross section is very useful because one of the lead terminals can be easily processed and used as a connector.
[Brief description of the drawings]
FIG. 1 is a perspective view illustrating connection between a lead terminal and wiring on a hybrid integrated circuit board according to an embodiment of the present invention.
FIG. 2 is a perspective view illustrating connection between a lead terminal and wiring on a hybrid integrated circuit board according to another embodiment of the present invention.
FIG. 3 is a diagram for explaining how to apply power of ultrasonic bonding.
FIG. 4 is a diagram illustrating vibration during bonding.
FIG. 5 is a diagram for explaining a connection between a hybrid integrated circuit board and lead terminals;
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Hybrid integrated circuit board 2 Wiring pattern 3 Bonding pad 4 Support part integral with case material 5 Lead terminal 6 Metal thin wires 30 and 32 Stopper part

Claims (4)

A substrate having at least an insulating surface; and
A wiring provided on the substrate, a bonding pad integrated with the wiring, a land on which a semiconductor element or a passive element is mounted;
A semiconductor element or a passive element electrically fixed to the land;
A support portion made of an insulating resin fixed to the substrate and integrally molded with lead terminals;
A bonding area provided in the support portion and exposing an upper surface of the lead terminal;
In an electronic device in which the bonding pad is disposed in the vicinity of the substrate located in the bonding area of the lead terminal, and has at least a bonding area of the lead terminal and a thin metal wire that electrically connects the bonding pad.
Under the bonding area lower layer of the lead terminal, the support portion extends to the substrate with a predetermined thickness,
An electronic device characterized in that the insulating resin covers the periphery of the bonding area on the upper surface of the lead terminal so that upward vibration is suppressed when the fine metal wire is connected to the bonding area with a vibrating bonding tool. . A substrate having at least an insulating surface;
A wiring provided on the substrate, a bonding pad integrated with the wiring, a land on which a semiconductor element or a passive element is mounted;
  A semiconductor element or a passive element electrically fixed to the land;
  A support portion made of an insulating resin fixed to the substrate and integrally molded with lead terminals;
  A bonding area provided in the support portion and exposing an upper surface of the lead terminal;
  In an electronic device in which the bonding pad is disposed in the vicinity of the substrate located in the bonding area of the lead terminal, and has at least a bonding area of the lead terminal and a thin metal wire that electrically connects the bonding pad.
  Under the bonding area lower layer of the lead terminal, the support portion extends to the substrate with a predetermined thickness,
When the fine metal wire is connected to the bonding area with a vibrating bonding tool, the cross section of the lead terminal is processed so that upward vibration is suppressed, and the periphery of the bonding area on the top surface of the lead terminal is the insulating resin. Electronic device characterized by being covered with. The electronic device according to claim 2 , wherein the lead terminal has an inverted T-shaped cross section . 3. The lead terminal according to claim 2, wherein a cross section of the lead terminal has a bowl shape, and an inner corner portion formed by a side surface and an upper surface is provided downward, and the corner portion has a shape exceeding 90 degrees. Electronic devices.

Images