JPS62243302A - Method of attaching lead parts in electronic parts - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a device in which a plurality of resistance elements are integrated on a single electrically insulating substrate, or a device having a function like a lag network. network resistor, such as
The present invention relates to a method of manufacturing electronic components such as hybrid ICs in which various electric elements and magnetic elements are arranged in multiple layers, and more specifically relates to a method of attaching a lead portion to a substrate in such a so-called multi-pin type electronic component. .

[Conventional technology and its problems]

For example, in a so-called network resistor, the sixth
As shown in the figure, an electrically insulating substrate 20 made of ceramic or the like
A plurality of thick film or thin film resistance elements 21 are formed on the top by pattern printing and baking in a predetermined shape, and after undercoating, trimming is performed to have a predetermined resistance value, and each resistance element 21 is electrically connected. After attaching the lead frame 22 to the 23 electrode parts on the left and right ends of the board 20, the outer periphery of the board, including the parts, is covered with a synthetic resin, using an exterior mold, powder coating, or glass. It is usual to provide a protective exterior 24 with a coat or the like. Afterwards, the connecting portions of the lead frame 22 are cut and separated to form each lead portion 25.

When attaching the lead frame 22 to the substrate 20,
In the conventional technique, as shown in FIG. 5, a comb-shaped lead frame 22 is prepared, which is punched and formed so that a predetermined number of lead parts 25 integrally protrude from one side.

At this time, as shown in FIG. 6, each of the lead parts 25 is provided with a cut line 26 of an appropriate length along the longitudinal direction of the lead part 25 from its protruding edge, and one end is formed into a straight end 25a.
while the other end 25b is curved so as to sandwich the substrate 20 from the front and back sides, and the pair of left and right glue frames 22 are approached from both left and right sides of the substrate 20 to sandwich it. Thereafter, in order to strengthen the sandwiched state, both ends 25a and 25b were pressed from above and below.

This method of attaching the lead portion has the following problems.

That is, in order to smoothly insert the ends 25a and 25b into the ends of the substrate 20, the one end 25a of each lead frame 22 is bent, and the ends 25a and 25b are bent.
It is necessary to form the gap between a and 25b in advance so that it is larger than the thickness of the substrate 20, which increases the cost for forming the lead frame.

In order to sandwich the ends 25a and 25b between the substrate 20, it is necessary to move the pair of left and right lead frames 22 closer to each other from the thickness direction of the substrate 20, and also to separate the substrate 20 and the lead frames 22 so that their thicknesses are equal to each other. It is necessary to arrange them parallel to each other in the direction, and the structure of the working machine for this process becomes complicated.

In order to prevent each lead frame 22 from slipping off the board 20, after the insertion operation, the both ends 25a, 25
A work step is required to press both the front and back sides of the substrate 20 from above and below.

Therefore, there is a problem that the number of work steps increases and the manufacturing efficiency of the resistor cannot be improved.

Furthermore, the strength for sandwiching the front and back sides of the substrate 20 is increased by the strength of the both ends 2.
5a and 25b, each of the widths must be greater than a certain level, and therefore the width of each leeway portion 25 cannot be made narrower.

Therefore, it is impossible to shorten the distance between the plurality of resistive elements 21 on the substrate 20, and as the number of lead portions 25 increases, it becomes difficult to miniaturize the network resistor.

Similar problems have also occurred in hybrid ICs.

The present invention has been made to solve the above-mentioned problems.

[Means for solving problems]

Therefore, in the present invention, circuit elements such as resistive elements and/or conductors, and conductor films that can be connected to these circuit elements and/or conductors are formed in advance on an electrically insulating substrate, and leads are attached to each conductor film. This method employs a method in which the substrate and the lead frame are overlapped so that the flat glue portions of the frame are in contact with each other, and the conductor film and the lead portion are bonded by soldering or the like.

[Action/effect of the invention]

In the present invention, a conductive film such as an electrode film is formed on a flat lead portion of a lead frame on a wide surface of an electrically insulating board such as a board in a resistor or a multilayer wiring board in an electronic component such as a hybrid IC. Since the board and lead frame are overlapped so that they are in contact with each other, alignment between the two is easy. In addition to eliminating the difficulty of positioning when approaching the lead frame in the direction of its thinner thickness, the present invention also eliminates the need for clamping work, and can greatly simplify the work process. There is no need to complicate the working machine for this purpose.

Furthermore, when the lead portions are made to protrude from the conductor portions on both the left and right sides of the board, according to the present invention, a frame-shaped lead frame with the lead portions integrally protruding from both the left and right sides is adopted. It is also possible to stack the substrates so as to place them on the flat surfaces of the lead portions, further improving the workability of positioning.

To bond the flat lead part of the lead frame to the conductive film of the similarly flat board, after temporarily attaching both, use normal dip soldering, one-way solder reflow by heating in a reflow oven, or bonding by applying heat pulses using a laser, etc. Various methods can be employed, such as a welding method using pressure and heat, and spot welding using pressure and heat, and the strength of the bonded portion can be improved as necessary.

In the conventional method of clamping between a pair of glued ends, in order to ensure the strength of the bond with the board at the clamping part, the entire front and back of the board, including the outer periphery of the clamping part, is further coated with synthetic resin or the like. Although it is necessary to package it, in the present invention,
When the conductive film and the lead part on the board are in contact with each other, it can be firmly bonded to the solder plate, etc., and it is possible to bond electrically, such as resistive elements formed on one or both sides of the board, such as in multilayer wiring boards. By simply applying an exterior coat to cover the surface of circuit elements such as elements and magnetic elements such as capacitors, it is possible to significantly reduce the manufacturing cost of electronic components such as resistors, and to protect the circuit elements and conductors on the board. It is also possible to omit the thickness of the outer covering on the side surface where there is no membrane, thereby making it possible to create a compact structure by that amount.

Conventionally, a pair of ends of a lead part for holding the ends of the board are located in the width direction of the lead part, so the leads for each circuit element such as a resistor element and/or conductor on the board are arranged in parallel. However, in the present invention, only the width dimension of the flat lead portion corresponding to one end in the conventional case is required, and a large number of resistors can be arranged. When circuit elements such as elements and/or conductors such as jumper wires are formed on one or both sides of a single board and their lead parts are arranged in parallel, the pinch that is the installation interval of the lead parts can be reduced. It also has the effect that electronic components such as ICs and ICs can be made more compact.

〔Example〕

Next, an embodiment in which the present invention is applied to a network resistor will be described. FIG. 1 shows a lead frame 1 in the form of a metal strip, with lead portions 2 partially arranged in parallel from both left and right sides within a window area la. It is punched out with a pinch (for example, 0.635 mm) to protrude.

Each of the lead portions 2 is bent so that the free end side thereof can come into contact with one side of a substrate 3, which will be described later, in a cross-sectional shape.

Reference numeral 3 is an electrically insulating substrate made of ceramic or the like. By dividing a large plate along weakened lines such as grooves, it can be made into a size that will become a product after forming resistive elements, etc., which will be described later. For example, length 5 val, width 14 inches, thickness O
-6~0,7va) can be formed into a square chip.

On one side (lower side) of the substrate 3, a thick or thin film (for example, 0.635 mm thick) is formed by pattern printing, baking, etc., a resistive paste that will become an electrical resistor.
A resistive element 4 is formed. A pair of left and right conductor films 5.5 are applied and formed by pattern printing a conductive paste such as Ag or Ag-Pd that can be electrically connected to the left and right end portions of the resistance element 4. Therefore, both the conductor films 5.5 partially overlap at both left and right end portions of the resistive element 4.

Next, as shown in FIG. 3, this substrate 3 is stacked on the upper surface of the lead part 2 of the lead frame l with the resistor element 4 facing downward, and each conductor film 5, 5 of the substrate 3 is The flat part of the lead part 2 should be brought into contact with the lead part 2.

In this state, each of the lead parts 2 and the conductor film 5 are bonded through a process such as soldering so that they can be electrically connected.

In this bonding process, preliminary soldering is applied to either or both of the flat lead portion 2 of the lead frame and the similarly flat conductor film 5.5 of the substrate, and then both are immersed in a dip-type solder bath. Bonding, so-called soldering,
A solder reflow method in which the conductor films 5, 5 of the substrate 3 are placed on the lead part 2 is heated in a flow furnace to melt and bond the conductor film 5.5 to the lead part 2; Various methods are used, such as a welding method in which a thermal halus is applied to the contact point using a laser or the like, or a so-called spot welding method in which pressure and heat are applied to the contact point between the lead part 2 and the conductor film 5. Can be adopted.

After bonding the substrate 3 and the lead frame 1 in this way, the surface of the resistive element 4 and the lead portion 2 on the substrate 3 are
In order to protect the adhesive part between the lead frame 1 and the conductor film 5, a protective sheath 6 is applied by coating and baking a glass coat (see FIG. 4), and then the lead frame 1 is cut to protect the adjacent lead part 2. Once separated, the resistor as a product is completed.

As described above, according to the present invention, it is difficult to align the board and the lead frame so that they approach each other in the direction of their thickness, as in the case where the board is held between a pair of ends of the conventional lead part. Complicated work steps can be omitted, the resistor manufacturing process can be simplified, and the equipment for that purpose does not need to be complicated.

Conventionally, a pair of ends for sandwiching the board are located in the width direction of the reat part, so when arranging the reat parts for each resistance element on the board in parallel, it is necessary to narrow the interval between adjacent pinches. However, in the present invention, only the width dimension of the flat curved portion 2 corresponding to one end in the conventional case is required, and a large number of circuit elements such as resistive elements 4 and/or conductors can be connected together. It is also possible to reduce the pitch when forming on one or both sides of a single substrate 3 and arranging the REEAT portions 2 in parallel thereto, thereby making it possible to make the resistor more compact.

It goes without saying that the present invention can be similarly applied to electronic components such as hybrid ICs.

[Brief explanation of drawings]

1 to 4 show embodiments of the present invention, in which FIG. 1 is a plan view of a lead frame, FIG. 2 is a bottom view of a substrate, FIG. 3 is a perspective view showing the method of the present invention, and FIG. The figure is a sectional view of a completed resistor, Figures 5 to 7 show the prior art, and Figures 5 to 7 show the prior art.
Diagram - I frame plan view, Figure 6 shows the board and IJ
-F A perspective view of the frame, and FIG. 7 is a sectional view of the resistor. 1.22... Lead frame, 1a... Window location, 2.25... Lead part, 3, 20... Board,
5゜5...Conductor film, 6...Protective exterior, 4.21
... Resistance element, 23 ... Electrode part, 25a, 25
b: End, 26: Cut line.

Claims (1)

[Claims] (1) Circuit elements such as resistive elements and/or conductors and conductor films that can be connected to these circuit elements and/or conductors are formed in advance on an electrically insulating substrate, and each conductor film has a flat surface on the lead frame. A method for attaching a lead part in an electronic component, characterized in that the substrate and the lead frame are overlapped so that the shaped lead parts are brought into contact with each other, and the conductive film and the lead part are bonded by soldering or the like.