JPH0453102B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a semiconductor device, and particularly to a carrier for an integrated circuit.

BACKGROUND OF THE INVENTION Integrated circuit carriers have an enclosure in which an integrated circuit can be placed and sealed.
This carrier starts near the integrated circuit and
It has multiple leads that pass through the side of the carrier and exit. Each lead is connected to one input/output pad of the integrated circuit by standard bonding techniques. In other words, the leads serve to connect the integrated circuit within the enclosure to the outside world. The leads connect the integrated circuit to a power source and operate the integrated circuit by making the necessary input/output connections.

A significant component of the manufacturing cost of semiconductor packages, particularly integrated circuit packages, is the package or carrier. A typical dual-in-line package (hereinafter referred to as DIP) is basically rectangular. The leads exit from the long sides of the rectangle, then turn at right angles and extend toward the bottom of the DIP package. As integrated circuits increase in functionality and become smaller in form factor, it is desirable to be able to make more connections to and from the integrated circuit, thus requiring an increase in the number of leads. Therefore,
Since the number of leads in the DIP package increases, the long sides of the rectangle must be made longer.

The problem is that the ends of the leads coming out of the DIP packaging cage are not constrained, so they tend to move laterally and come into contact with other leads. Unconstrained lead ends can lead to lead breakage and increase installation costs, as the leads must be straightened prior to being attached to a printed circuit board, for example.

<Problems to be Solved by the Invention> In order to eliminate these drawbacks, a protrusion with a continuous surface is formed from the side of the DIP package so as to protrude beyond the bottom surface, and the leads are It can be formed so that it comes out from the side surface of the package cage, extends from the side surface of the protruding stripe along a ridge portion corresponding to the lower end of the protruding stripe, and extends toward the bottom surface of the DIP package cage. If configured like this,
Since the lead is supported and restrained by the protrusion, the above-mentioned problems such as breakage of the lead are alleviated. However, in such DIP package cages, the ends of the leads that exit the package side and extend beyond the ridges are not constrained, so the leads tend to move laterally, thereby causing contact with adjacent leads. There is a risk that it may be damaged or damaged.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a carrier for integrated circuits that can restrain and support the ends of leads pulled out from a package and stably hold the leads.

<Means for Solving the Problems> According to the present invention, the carrier for an integrated circuit according to the present invention has a top surface 26, a bottom surface 28 parallel to the top surface,
an enclosure having at least one side surface extending from the top surface to the bottom surface, the enclosure further including a rounded top portion 62 extending beyond the bottom surface and located away from the side surface; At least one sloped portion 64 extending from the top toward the bottom
The bottom surface has a plurality of recesses 50 disposed adjacent to the ridges, one end located within the enclosure, and one end extending through the sides of the enclosure. , a portion extending along the inclined portion 64 so as to extend around the tip and be restrained in the first direction, and a portion of the recess so as to be restrained in a direction substantially perpendicular to the first direction. 1
The lead includes a plurality of leads having opposite ends located within the lead.

<Operations and Effects of the Invention> According to the present invention, each lead drawn out from the side surface of the package cage extends along the ridge protruding beyond the bottom surface and extends beyond the top of the ridge portion to the individual leads formed on the bottom surface. Since it is inserted into the recess of and is restrained, it is prevented from coming into contact with other objects at this end,
This substantially prevents the leads from laterally displacing and contacting adjacent leads, thereby causing short circuits and damage. For this reason, since the strength and rigidity do not need to be large, the leads can be made thinner or thinner, and the leads can be made lighter and the distance between the leads can be reduced. If desired, the ridge can be omitted and the lead end can be placed within the recess without a support such as a ridge.

<Example> As shown in FIG. 1, the basic shape of the carrier 20 is a square. The carrier 20 has an enclosure 22 and a plurality of leads 24. The leads can be made of a conductive material, such as a copper alloy. Enclosure 22 may be made of plastic, such as epoxy. Carrier 20 may be of any suitable shape, but as shown in FIGS. 1, 2, and 3, it has a top surface 26, a bottom surface 28, and four sides 32-35, with The bottom surface 28 is square, and the side surfaces 32 to 35 are rectangular, so that the overall shape is a flat box. FIG. 1 is a partially cutaway view of the top surface 26, and shows
Integrated circuit 29 is shown connected to leads 24 by a plurality of thin bonding wires 40 .

Since all leads 24 have the same configuration, it will suffice to consider a particular lead 43. One end of lead 43 is located adjacent to integrated circuit 29 and is connected to the integrated circuit by one bonding wire 40 . The lead 43 passes through the side surface of the enclosure 22 at approximately the center of the distance between the top surface 26 and the bottom surface 28, as shown in FIG. Lead 43 has flat sides 47 (FIGS. 3 and 5).

The corners connecting the sides 32-35 may be of any suitable shape, such as rounded, pointed or chamfered. Side surfaces 32 and 34 constitute a pair of side surfaces;
These sides are parallel and have approximately the same size. The same applies to side surfaces 33 and 35.

The lead 43 extends from one end 45 within the enclosure 22 to the outside of the side surface 34 (see FIG. 3), and further extends along the side surface 34 toward the bottom surface 28 with a flat surface 47. There is. All leads 24 exit the enclosure approximately centrally between the top surface 26 and the bottom surface 28. All leads have a flat surface 47. The bottom surface 28 has a plurality of recesses 5
0 (Figure 2). These recesses are separated from each other by a bottom section that is at the same level as the rest of the bottom surface 28. The bottom portion between the recesses may be slightly above or below the remaining bottom portion. The ridge may also be level with the bottom surface if the recess is deep. As shown in FIG. 2, the ends of leads 24 are within recesses 50.

As shown in Figure 3, each lead 2
4 extends beyond the plurality of ridges 53. These plurality of raised portions 53 are formed by protrusions extending beyond the bottom surface 28 along each side surface 32-35.
The raised portion has a slope that is coplanar with the side surfaces 32-35. Each lead passes into one recess 50 over the associated ridge. Therefore, each recess 50 is provided corresponding to the associated ridge,
Each ridge is associated with one lead.
If these ridges are formed by one protrusion, it is only necessary to associate one recess with one lead.

As shown in FIG. 4, each lead 24 extends beyond the ridge 53 and into the recess 50.
Each recess is separated by a bottom surface portion that is at the same or slightly higher level than the bottom surface forming the ribs 56. In this manner, the ends of the leads 24 extend along the sides, but lateral movement parallel to the sides is substantially restrained by the ribs 56. Therefore, the rib 56 is the lead 2
4 and prevents it from coming into contact with the adjacent lead 24.

Because the ribs prevent lateral movement, the leads can be made of thin or thin material.

As shown in Figure 5, one lead 4
3 has a flat surface 47 opposite one associated ridge 58 and extending beyond the ridge 58. Since the ridges 58 are identical in shape to the other ridges 53, it will be sufficient to describe one ridge 58 in detail. The slope 60 of the ridge 58 is coplanar with the side surface 34. The side surface 34 extends from its center to the bottom surface 28.
The section up to the same level can be made into a slope with a small inclination angle (for example, about 3 degrees). The surface of the ridge 58 extends from the ramp 60 through the rounded top 62 and from the rounded top 62 into a corresponding recess 66 . The angle of the second slope 64 with respect to the side surface is approximately 25 degrees. The ramp 64 extends generally away from the side surface 34 toward the bottom surface 28 and toward the opposite side surface 32 (FIG. 2).

In FIG. 5, two positions of lead 43 are shown. The lead 43 is first bent at the rounded top 62, as shown in dotted lines, and then a punch 68 (shown in dotted lines) contacts the portion of the lead beyond this bent portion. Punch 68 deforms the lead and is angularly displaced to a second position adjacent ramp 64 as shown in solid line. In this way, lead 4
3 ends 70 are placed in one recess 66. End 70 is prevented from moving laterally by ribs 73 and 74 (FIG. 2) of ribs 56. The corners 76 of the bottom surface 28 are also raised to obtain ribs, such as ribs 74 in FIG.

Even if a force is applied to pull the lead 43 away from the slope 60 and the side surface 34 of the enclosure 22, the end 70 of the lead 43 and a portion near it will contact the slope 64 to prevent such movement. After the deformation by the punch 68, the lead end 70 contacts the slope 64, so that the flat side surface 47 is not separated from the slope 60 due to its spring back action. Since the end 70 is within the recess 66, it is protected from contact with other objects. The ends of the other leads 24 are also within their respective recesses 50 and are protected from contact with other objects.

As shown in FIG. 5, the punch 68 moves from a first position shown in dotted lines on the right side to a second position shown in solid lines. This causes the lead 43 to bend along the rounded top 62,
Contacting or proximate to the slope 64. When lead 43 is deformed, even after punch 68 is removed and no longer in contact with lead 43, end 70
remains close to slope 64.

The enclosure 22 has chamfered edges 79 and 8.
0 (Fig. 1), and these edges are
It is useful for aligning the carrier in order to properly connect the leads to, for example, a printed circuit board.

In FIG. 6, two adjacent leads 100 and 102 of leads 24 are shown extending out from enclosure 22. In FIG. Leads 100 and 102 have openings or holes 106 and 108, respectively, near where they exit enclosure 22. The holes shown are rectangular, but may be any suitable shape. This hole increases the flexibility of the lead. Leads 100 and 102 extend downwardly into narrow portions 120 and 122, respectively. Leads 100 and 102 have tapered edges 110, 112 and 114, 116 between narrow portions 120 and 122, respectively. The narrow portions 120 and 122 extend beyond the ridges 130 and 132 into the two recesses 50.
(not shown in FIG. 6).
Leads 100 and 102 can be soldered to printed circuit board 200 at the lower portions 136 and 138 of the top of their respective ridges.

Connect leads 100 and 102 to printed circuit board 2
When soldering to the 00 contact pads 202 and 204, the lower portions 136 and 138 are in contact with the contact pads 202 and 204, and the solder 206 is deposited on the narrow portions 120 and 122 (only a portion of the solder adhered to the leads 102). (Illustrated). The solder is applied to the lower portions of the leads 136 and 1.
38 to connect the leads to printed circuit board 200. Soldering can be performed by reflow, ripping, waving or other suitable methods.

when connected to a printed circuit board or when coming into contact with other objects (e.g. when coming into contact with other carriers during transport) or when being inserted into a socket.
The raised portions 130, 132 serve to hold the leads 100, 102. When the enclosure 22 is inserted into the socket, the leads extending along the sides of the enclosure 22 between the tapered portion 60 and the socket entrance contact the conductors within the socket. Raised portion 13
0,132 or limit the amount of solder that accumulates between leads 100, 102 and enclosure 22 as a result of wicking (solder flow) effects, allowing bridging of solder 206 between adjacent leads 100, 102. is prevented.

Leads 100, 102 through holes 106, 108
is flexible and can compensate for changes in the dimensions of the printed circuit board due to thermal effects. Leads 100 and 102 are separated by region 140. The size of region 140 between lead 100 and lead 102 is approximately equal to the width of lead 100. Lead 102 has approximately the same width as lead 100. The width of the leads is the distance between them,
That is, it may be larger than the size of the area 140. If leads 100 and 102 are not perfectly parallel, the width of the leads may be made slightly less than the spacing between them. Thus, the width of region 140 can be slightly greater than, equal to, or slightly less than the width of lead 100. By spacing the leads by their relative widths, leads from other carriers (not shown) similar to carrier 20 are prevented from interlocking between leads 100 and 102. be done. Such engagement can result in damage to the leads, especially during automated processing steps.

Although the invention has been described with reference to the drawings,
It goes without saying that modifications other than those mentioned in the above description are possible within the scope of the invention.

[Brief explanation of the drawing]

FIG. 1 is a plan view of the integrated circuit carrier of the present invention, with a portion cut away to show internal details (not to scale). Second
The figure is a bottom view, Figure 3 is a side view, Figure 4 is a sectional view taken along line 4--4 in Figure 2, and Figure 5 is a cross-sectional view along line 5 in Figure 2.
6 is a partial view of the carrier showing the sides of two adjacent leads; FIG. (Explanation of symbols), 26...Top surface, 28...Bottom surface,
32-35...side, 43...lead, 50...
Recess, 53... Protuberance, 62... Top, 64...
Slope.

Claims (1)

[Claims] 1. A top surface, a bottom surface parallel to the top surface, and at least one side surface extending from the top surface to the bottom surface,
The bottom surface has at least one protuberance that protrudes outward along the surface direction of the side surface at a boundary with the side surface, and the protuberance includes a rounded top and a rounded top. , a sloped portion extending from the top toward the bottom surface, and the bottom surface has a plurality of recesses adjacent to the sloped portion, and further, the bottom surface has a plurality of recesses located in the enclosure. a portion extending through and along the side surface and extending along the raised portion to a recess in the bottom surface; and another portion located within the recess. A carrier for an integrated circuit comprising a plurality of leads, each having an end and a plurality of leads. 2. In the carrier for an integrated circuit according to claim 1, the raised portion is composed of a plurality of raised portions, and each of the plurality of leads is held by one raised portion corresponding to each lead. A carrier for integrated circuits characterized by: 3. The carrier for an integrated circuit according to claim 1, wherein the lead contacts the inclined portion to suppress movement of the lead.