CN1233930A - Method and device for mounting components on a support plate - Google Patents

Abstract

The electronics industry tends to use components that can be surface mounted on a substrate such as a circuit board. The components (5) can be surface-mounted upright on the circuit board (7) by using the leads capable of being surface-mounted on the components and the "single row in-line" method, and the component leads are also surface-mounted on the board. The bottom end of the lead wire (8) can be bent to form a foot (10) so as to effectively contact the circuit board. Guide and support pins are used to hold the component in place during mounting and connection and to support the leads on the component when mounted to a circuit board.

Description

Method and device for mounting components on a support plate

The present invention relates to a method of surface mounting an upright element on a support plate, and to an apparatus for surface mounting the upright element on a support plate.

Today's components that need to be mounted upright on eg a circuit board typically have straight leads that are inserted into holes in order to secure the component to the circuit board and to make electrical contact between the component and the circuit board. The leads can be configured as single-in-line (SIL). When installing this kind of component on the circuit board, the lead wire is inserted into the metal-plated hole on the board, and then the component is firmly fixed in the hole through the interaction of the lead wire, and an electrical connection is formed in the hole, so that the component The necessary electrical contact is obtained between the leads and the circuit board.

In the electronics industry, it is highly desirable that components mounted on a substrate, such as a circuit board, be surface mounted. Overall, components of this nature take up less space on the circuit board, since it is no longer necessary, for example, to form many holes. Such holes make it difficult to obtain a wire pattern on the underlying layer. In addition, the production process of circuit boards can be rationalized when only surface mount components can be used. Because the installation process of the hole and the wave soldering process can be omitted, the production is simple and the cost is low.

Utilize surface mountable leads on the component combined with single in-line technology, where the bottom end of the lead can be bent to form a foot in contact with the circuit board, and apply guide and support pins during the process of mounting and connecting the component to enable With the component mechanically held in place and the leads fastened to the finished circuit board, a stand-up component can be mounted on the circuit board with the component leads surface mounted on the board.

Surface mount contact leads can be produced from existing lead frames or from specially adapted contact leads. The leads can be bent into a suitable shape using a tool to form a foot on the corresponding lead, so that the lead can be effectively connected to the connection surface of the circuit board, regardless of the position occupied by the component when mounted.

The number of guide and support pins is preferably two or more, and the pins can be straight or slightly curved, but are always longer than the connecting leads so that these pins can be inserted into the guide holes of the circuit board. The guide and support pins allow mounting of components without loose clamps. Depending on the method used and the size of the components used it is also possible to use guide and support pins with few leads.

1A and 1B are distribution views of components mounted on a lead frame;

Figures 2A and 2B show the element of Figure 1 with its leads separated from the lead frame and formed into contact leads and guide and support pins of the present invention;

3A and 3B are views showing that the components of FIG. 2 are installed and connected to a circuit board;

Figures 4A and 4B show alternative embodiments of guide and support pins;

Figures 5A and 5B show alternative embodiments of contact leads.

Overall, surface-mount components use less space than components mounted in holes because better utilization of the surface of the underlying circuit board layer is used to deploy the circuit pattern. While discovering the greater capability of surface-mount components in the production of circuit boards, the potential to rationalize production was also discovered, as all components could be surface-mounted, and the process of mounting in holes and wave soldering could be omitted on the production line .

Starting, for example, from a rolled strip which generally consists of several longitudinally joined lead frame materials (see FIG. 1 ) in which each individual contact point 3 of a contact lead 2 is first connected to a corresponding contact face 4 on a component 5 , followed by removal of non-functional leads. The contact points 3 on the contact leads 2 of the lead frame can be firmly soldered to the corresponding component contact points 4 . The individual elements 5 are separated and tested from the frame-attached elements, see FIG. 2 , eg cut from them. This operation may be performed partly immediately before packaging, or during packaging, depending on the packaging process used. By forming at least one lead as a guide and support pin 6 suitable for perforated mounting in a circuit board 7 with a possible electrical connection to said circuit board, the remaining leads can be used as electrical contact leads between the component and the board 8.

Existing lead frames can thus be used for components to be surface mounted. Alternatively contact leads and guide and support pins can be applied directly to the component from outside for connection thereto. To fix the component in place on the support plate, two guide pins 6 are usually used, which pins are formed with lead wires that are usually cut off. The guide pins may be straight or slightly curved or inclined, as shown at 6' in Figure 4A, for example where the contact points and guide holes are aligned on the support plate. In some cases, it is also suitable to place the component upright directly on the support plate, in which case shortened contact leads and guide and support pins can be used, see Figure 4B.

Guide and support pin mounting holes 9 are machined in the circuit board 7 to facilitate mounting the element 5 on the board, and the above-mentioned pins and holes function as guide elements and support the document at predetermined positions on the board. The hole 9 on the circuit board is preferably not plated to maintain the correct hole size. The size of the pilot holes can vary according to the tolerance requirements of the assembly machines used by the lead frame and circuit board fabrication plants.

Despite the need for drilled pilot holes in the board, there is a saving on the part of the board manufacturer, as the large number of holes that would be required if using through-hole mounted components is not required at the moment. The provision of pilot holes in the board does not seem to pose a disadvantage, since the board has to withstand the drilling operation in order to make connections between the different layers of the board through the holes.

In addition to the above-described method steps for producing the component with contact leads 8 and guide and support pins 6 , bending of the lead ends 10 and equipment for encapsulation are required. The ends of the contact leads are preferably J-shaped as shown in Figures 3B, 4A, and 5A, gull-winged as shown in Figure 5B, and cut-away as shown in Figure 5C, where they are straight leads for direct connection on the circuit board. When the component is mounted on the circuit board, the free ends of the pins projecting outwardly can be removed, or, if necessary, bent or angled, to ensure that the component is securely fixed to the circuit board.

When the end of the contact lead is J-shaped, there is always sufficient surface contact with the contact surface on the circuit board, and this contact can ensure electrical contact. It is also possible to form joints 11 around which there is exactly the same amount of solder material even if the components are skewed to one side. The guide pins can be left completely straight, or can be slightly bent so that they line up with the center of the J-hook. Another kind of J-shaped bending is J-shaped hooks that are mirror images of each other, as shown in FIG. 5A , this bending is beneficial to make the components more firmly arranged on the circuit board. Similar mirror-symmetric configurations are also conceivable that contribute to enhanced component stability, such as mirror-symmetrical gull-wing and other similar shapes at the ends of the leads.

When packaging finished components with connecting leads and guide and support pins, the pins longer than the contact leads can be used as the contact surface of the adhesive tape, the finished components are wound on a delivery reel and delivered to the user.

Claims (12)

1. A method for upright mounting of a component on a support plate, characterized in that a component with leads is provided, at least one of which is formed as a guide and support pin, which is used when mounting the above-mentioned component on the support plate Components can be guided and supported while the rest of the leads are connected. 2. 3. The method of claim 1, wherein the ends of said leads are bent so as to contact the support plate before said connection is made. 3. 3. A method as claimed in claim 1, characterized in that, prior to making said connection, the contact leads are cut so that the straight leads are in direct contact with the support plate. 4. A device for surface-mounting components upright on a support plate, characterized in that leads (2) are connected to the component (5), at least one of which is adapted to be formed as a guide and support pin (6), the remaining leads being The function of the contact lead is used to connect the electrical contact point (4) of the component. When the component is mounted on the support plate (7), the guide and support pins are inserted into the holes (9) of the support plate, and the electrical leads are connected to the support plate (7). corresponding contact points on the board. 5. A device according to claim 4, characterized in that the contact points and guide holes are mounted in a row on a support or circuit board (7), and said guide and support pins (6) are inclined. 6. 4. Device according to claim 4, characterized in that said guide and support pins (6) are connectable to a belt. 7. 5. Arrangement according to claim 4, characterized in that the ends of the contact leads (8) are bent so that a better connection to the circuit board (7) can be made. 8. 7. Arrangement according to claim 7, characterized in that the contact lead end (10) is J-shaped. 9. 7. Arrangement according to claim 7, characterized in that the contact terminal wires (10) are gull-wing shaped. 10. 9. A device as claimed in any one of claims 7 to 9, characterized in that the contact lead ends face in mutually different directions. 11. 4. A device as claimed in claim 4, characterized in that the contact leads are cut away so as to form straight lines for direct connection. 12. 11. Arrangement according to claims 4-11, characterized in that, prior to assembly, the contact leads (8) and the guide and support pins (6) are formed by the leads (2) on the lead frame (1).

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